title: Job satisfaction

text: Employee recognition is not only about gifts and points. It's about changing the corporate culture in order to meet goals and initiatives and most importantly to connect employees to the company's core values and beliefs. Strategic employee recognition is seen as the most important program not only to improve employee retention and motivation but also to positively influence the financial situation. The difference between the traditional approach (gifts and points) and strategic recognition is the ability to serve as a serious business influencer that can advance a company's strategic objectives in a measurable way. "The vast majority of companies want to be innovative, coming up with new products, business models and better ways of doing things. However, innovation is not so easy to achieve. A CEO cannot just order it, and so it will be. You have to carefully manage an organization so that, over time, innovations will emerge."


title: Job satisfaction

text: Mood and emotions at work are related to job satisfaction. Moods tend to be longer lasting but often weaker states of uncertain origin, while emotions are often more intense, short-lived and have a clear object or cause.


title: Job satisfaction

text: Some research suggests moods are related to overall job satisfaction. Positive and negative emotions were also found to be significantly related to overall job satisfaction.


title: Job satisfaction

text: Frequency of experiencing net positive emotion will be a better predictor of overall job satisfaction than will intensity of positive emotion when it is experienced.


title: Job satisfaction

text: Emotion work (or emotion management) refers to various types of efforts to manage emotional states and displays. Emotion management includes all of the conscious and unconscious efforts to increase, maintain, or decrease one or more components of an emotion. Although early studies of the consequences of emotional work emphasized its harmful effects on workers, studies of workers in a variety of occupations suggest that the consequences of emotional work are not uniformly negative.


title: Job satisfaction

text: It was found that suppression of unpleasant emotions decreases job satisfaction and the amplification of pleasant emotions increases job satisfaction.


title: Job satisfaction

text: The influence that genetics has had on a variety of individual differences is well documented. Some research suggests genetics also play a role in the intrinsic, direct experiences of job satisfaction like challenge or achievement (as opposed to extrinsic, environmental factors like working conditions). Notably, Arvey et al (1989) examined job satisfaction in 34 pairs of monozygotic twins who were reared apart to test for the existence of genetic influence on job satisfaction. After correcting for age and gender, they obtained an intra-class correlation of .31. This suggests that 31% of variance in job satisfaction has a genetic basis, the estimate would be slightly larger if corrected for measurement error. They also found that evidence of genetic heritability for job characteristics, such as complexity level, motor skill requirements, and physical demands.


title: Job satisfaction

text: Some research suggests an association between personality and job satisfaction. Specifically, this research describes the role of negative affectivity and positive affectivity. Negative affectivity is related strongly to the personality trait of neuroticism. Individuals high in negative affectivity are more prone to experience less job satisfaction. Positive affectivity is related strongly to the personality trait of extraversion. Those high in positive affectivity are more prone to be satisfied in most dimensions of their life, including their job. Differences in affectivity likely impact how individuals will perceive objective job circumstances like pay and working conditions, thus affecting their satisfaction in that job.


title: Job satisfaction

text: There are two personality factors related to job satisfaction, alienation and locus of control. Employees who have an internal locus of control and feel less alienated are more likely to experience job satisfaction, job involvement and organizational commitment. A meta-analysis of 187 studies of job satisfaction concluded that high satisfaction was positively associated with internal locus of control. The study also showed characteristics like high Machiavellianism, narcissism, trait anger, type A personality dimensions of achievement striving and impatience/irritability, are also related to job satisfaction.


title: Job satisfaction

text: Psychological well-being (PWB) is defined as "the overall effectiveness of an individual's psychological functioning" as related to primary facets of one's life: work, family, community, etc. There are three defining characteristics of PWB. First, it is a phenomenological event, meaning that people are happy when they subjectively believe themselves to be so. Second, well-being involves some emotional conditions. Particularly, psychologically well people are more prone to experience positive emotions and less prone to experience negative emotions. Third, well-being refers to one's life as a whole. It is a global evaluation. PWB is primarily measured using the eight-item Index of Psychological Well-Being developed by Berkman (IPWB). IPWB asks respondents to reply to a series a questions on how often they felt "pleased about accomplishing something", "bored", "depressed or unhappy", etc.


title: Job satisfaction

text: PWB in the workplace plays an important role in determining job satisfaction and has attracted much research attention in recent years. These studies have focused on the effects of PWB on job satisfaction as well as job performance. One study noted that because job satisfaction is specific to one's job, the research that examined job satisfaction had not taken into account aspects of one's life external to the job. Prior studies had focused only on the work environment as the main determinant of job satisfaction. Ultimately, to better understand job satisfaction (and its close relative, job performance), it is important to take into account an individual's PWB. Research published in 2000 showed a significant correlation between PWB and job satisfaction (r = .35, p < .01). A follow-up study by the same authors in 2007 revealed similar results (r = .30, p < .01). In addition, these studies show that PWB is a better predictor of job performance than job satisfaction alone. Job satisfaction more associate to mental health than physical health.


title: Job satisfaction

text: The majority of job satisfaction measures are self-reports and based on multi-item scales. Several measures have been developed over the years, although they vary in terms of how carefully and distinctively they are conceptualized with respect to affective or cognitive job satisfaction. They also vary in terms of the extent and rigour of their psychometric validation.


title: Job satisfaction

text: The Brief Index of Affective Job Satisfaction (BIAJS) is a four-item, overtly affective as opposed to cognitive, measure of overall affective job satisfaction. The BIAJS differs from other job satisfaction measures in being comprehensively validated not just for internal consistency reliability, temporal stability, convergent and criterion-related validities, but also for cross-population invariance by nationality, job level, and job type. Reported internal consistency reliabilities range between 0.81 and 0.87.


title: Job satisfaction

text: The Job Descriptive Index (JDI) is a specifically cognitive job satisfaction measure. It measures one's satisfaction in five facets: pay, promotions and promotion opportunities, coworkers, supervision, and the work itself. The scale is simple, participants answer either yes, no, or can't decide (indicated by '?') in response to whether given statements accurately describe one's job.


title: Job satisfaction

text: Other job satisfaction questionnaires include: the Minnesota Satisfaction Questionnaire (MSQ), the Job Satisfaction Survey (JSS), and the Faces Scale. The MSQ measures job satisfaction in 20 facets and has a long form with 100 questions (five items from each facet) and a short form with 20 questions (one item from each facet). The JSS is a 36 item questionnaire that measures nine facets of job satisfaction. Finally, the Faces Scale of job satisfaction, one of the first scales used widely, measured overall job satisfaction with just one item which participants respond to by choosing a face.


title: Job satisfaction

text: Job satisfaction can be indicative of work behaviors such as organizational citizenship, and withdrawal behaviors such as absenteeism, and turnover. Further, job satisfaction can partially mediate the relationship of personality variables and deviant work behaviors.


title: Job satisfaction

text: One common research finding is that job satisfaction is correlated with life satisfaction. This correlation is reciprocal, meaning people who are satisfied with life tend to be satisfied with their job and people who are satisfied with their job tend to be satisfied with life. In fact, a 2016 FlexJobs survey revealed 97% of respondents believe a job that offered flexibility would positively impact their lives, 87% think it would help lower stress and 79% think the flexibility would help them live healthier. Additionally, a second survey of 650 working parents revealed that flexible work arrangements can positively affect people's personal health, as well as improve their romantic relationships and 99% of respondents believe a flexible job would make them a happier person in general. However, some research has found that job satisfaction is not significantly related to life satisfaction when other variables such as nonwork satisfaction and core self-evaluations are taken into account.


title: Job satisfaction

text: An important finding for organizations to note is that job satisfaction has a rather tenuous correlation to productivity on the job. This is a vital piece of information to researchers and businesses, as the idea that satisfaction and job performance are directly related to one another is often cited in the media and in some non-academic management literature. A recent meta-analysis found surprisingly low correlations between job satisfaction and performance. Further, the meta-analysis found that the relationship between satisfaction and performance can be moderated by job complexity, such that for high-complexity jobs the correlation between satisfaction and performance is higher than for jobs of low to moderate complexity. Additionally, one longitudinal study indicated that among work attitudes, job satisfaction is a strong predictor of absenteeism, suggesting that increasing job satisfaction and organizational commitment are potentially good strategies for reducing absenteeism and turnover intentions. Recent research has also shown that intention to quit alone can have negative effects on performance, organizational deviance, and organizational citizenship behaviours. In short, the relationship of satisfaction to productivity is not as straightforward as often assumed and can be influenced by a number of different work-related constructs, and the notion that "a happy worker is a productive worker" should not be the foundation of organizational decision-making. For example, employee personality may even be more important than job satisfaction in regards to performance. Job satisfaction has also been found to be impacting the shorter job tenure among persons with severe mental illness.


title: Job satisfaction

text: Numerous studies have been done to show the correlation of job satisfaction and absenteeism. For example, Goldberg and Waldman looked at absenteeism in two dimensions as total time lost (number of missed days) and the frequency of time lost.


title: Job satisfaction

text: Self-reported data and records-based data were collected and compared. Following absenteeism measures were evaluated according to absenteeism predictors.


title: Job satisfaction

text: Only three categories of predictors had a significant relationship ratio and were taken in account further:


title: Job satisfaction

text: This research results revealed that absenteeism cannot be predicted by job satisfaction, although other studies have found significant relationships.


title: Okazaki fragments

text: Okazaki fragments are short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication. They were discovered in the 1960s by the Japanese molecular biologists Reiji and Tsuneko Okazaki, along with the help of some of their colleagues.


title: Okazaki fragments

text: During DNA replication, the double helix is unwound and the complementary strands are separated by the enzyme DNA helicase, creating what is known as the DNA replication fork. Following this fork, DNA primase and DNA polymerase begin to act in order to create a new complementary strand. Because these enzymes can only work in the 5’ to 3’ direction, the two unwound template strands are replicated in different ways. One strand, the leading strand, undergoes a continuous replication process since its template strand has 3’ to 5’ directionality, allowing the polymerase assembling the leading strand to follow the replication fork without interruption. The lagging strand, however, cannot be created in a continuous fashion because its template strand has 5’ to 3’ directionality, which means the polymerase must work backwards from the replication fork. This causes periodic breaks in the process of creating the lagging strand. The primase and polymerase move in the opposite direction of the fork, so the enzymes must repeatedly stop and start again while the DNA helicase breaks the strands apart. Once the fragments are made, DNA ligase connects them into a single, continuous strand. The entire replication process is considered "semi-discontinuous" since one of the new strands is formed continuously and the other is not.


title: Okazaki fragments

text: The work of Kiwako Sakabe, Reiji Okazaki and Tsuneko Okazaki provided experimental evidence supporting the hypothesis that DNA replication is a discontinuous process. Previously, it was commonly accepted that replication was continuous in both the 3' to 5' and 5' to 3' directions. 3' and 5' are specifically numbered carbons on the deoxyribose ring in nucleic acids, and refer to the orientation or directionality of a strand. In 1967, Tsuneko Okazaki and Toru Ogawa suggested that there is no found mechanism that showed continuous replication in the 3' to 5' direction, only 5' to 3' using DNA polymerase, a replication enzyme. The team hypothesized that if discontinuous replication was used, short strands of DNA, synthesized at the replicating point, could be attached in the 5' to 3' direction to the older strand.


title: Okazaki fragments

text: To distinguish the method of replication used by DNA experimentally, the team pulse-labeled newly replicated areas of "Escherichia coli" chromosomes, denatured, and extracted the DNA. A large number of radioactive short units meant that the replication method was likely discontinuous. The hypothesis was further supported by the discovery of polynucleotide ligase, an enzyme that links short DNA strands together.


title: Okazaki fragments

text: In 1968, Reiji and Tsuneko Okazaki gathered additional evidence of nascent DNA strands. They hypothesized that if discontinuous replication, involving short DNA chains linked together by polynucleotide ligase, is the mechanism used in DNA synthesis, then "newly synthesized short DNA chains would accumulate in the cell under conditions where the function of ligase is temporarily impaired." "E. coli" were infected with bacteriophage T4 that produce temperature-sensitive polynucleotide ligase. The cells infected with the T4 phages accumulated a large number of short, newly synthesized DNA chains, as predicted in the hypothesis, when exposed to high temperatures. This experiment further supported the Okazakis' hypothesis of discontinuous replication and linkage by polynucleotide ligase. It disproved the notion that short chains were produced during the extraction process as well.


title: Okazaki fragments

text: The Okazakis' experiments provided extensive information on the replication process of DNA and the existence of short, newly synthesized DNA chains that later became known as Okazaki fragments.


title: Okazaki fragments

text: Two pathways have been proposed to process Okazaki fragments: the short flap pathway and the long flap pathway.


title: Okazaki fragments

text: In the short flap pathway in eukaryotes the lagging strand of DNA is primed in short intervals. In the short pathway only, the nuclease FEN1 is involved. Pol δ frequently encounters the downstream primed Okazaki fragment and displaces the RNA/DNA initiator primer into a 5′ flap. The FEN1 5’-3’ endonuclease recognizes that the 5’ flap is displaced, and it cleaves, creating a substrate for ligation. In this method the Pol a-synthesized primer is removed. Studies show that in the FEN1 suggest a ‘tracking; model where the nuclease moves from the 5’ flap to its base to preform cleavage. The Pol δ does not process a nuclease activity to cleave the displaced flap. The FEN1 cleaves the short flap immediately after they form. The cleavage is inhibited when the 5’ end of the DNA flap is blocked either with a complementary primer or a biotin-conjugated streptavidin moiety. DNA ligase seals the nick made by the FEN1 and it creates a functional continuous double strand of DNA. PCNA simulates enzymatic functions of proteins for both FEN1 and DNA ligase. The interaction is crucial in creating proper ligation of the lagging DNA strand. Sequential strand displacement and cleavage by Pol δ and FEN1, respectively, helps to remove the entire initiator RNA before ligation. Many displacements need to take place and cleavage reactions are required to remove the initiator primer. The flap that is created and processes and it is matured by the short flap pathway.


title: Okazaki fragments

text: In some cases, the FEN1 lasts for only a short period of time and disengages from the replication complex. This causes a delay in the cleavage that the flaps displaced by Pol δ become long. When the RPA reaches a long enough length, it can bind stably. When the RPA bound flaps are refactorized to FEN1 cleavage the require another nuclease for processing, this has been identified as an alternate nuclease, DNA2. DNA2 has defects in the DEN1 overexpression. The DNA2 showed to work with FEN1 to process long flaps. DNA2 can dissociate the RPA from a long flap, it does this by using a mechanism like the FEN1. It binds the flap and threads the 5’ end of the flap. The nuclease cleaves the flap making it too short to bind to the RPA, the flap being too short means it is available for FEN1 and ligation. This is known as the long flap method. DNA2 can act as FEN1 as a backup for nuclease activity but it is not an efficient process.


title: Okazaki fragments

text: Until recently, there were only two known pathways to process Okazaki fragments. However, current investigations have concluded that a new pathway for Okazaki fragmentation and DNA replication exists. This alternate pathway involves the enzymes Pol δ with Pif1 which perform the same flap removal process as Pol δ and FEN1.


title: Okazaki fragments

text: Primase adds RNA primers onto the lagging strand, which allows synthesis of Okazaki fragments from 5' to 3'. However, primase creates RNA primers at a much lower rate than that at which DNA polymerase synthesizes DNA on the leading strand. DNA polymerase on the lagging strand also has to be continually recycled to construct Okazaki fragments following RNA primers. This makes the speed of lagging strand synthesis much lower than that of the leading strand. To solve this, primase acts as a temporary stop signal, briefly halting the progression of the replication fork during DNA replication. This molecular process prevents the leading strand from overtaking the lagging strand.


title: Okazaki fragments

text: New DNA is made during this phase by enzymes which synthesize DNA in the 5’ to 3’ direction. DNA polymerase is essential for both the leading strand which is made as a continuous strand and lagging strand which is made in small pieces in DNA Synthesis.  This process happens for extension of the newly synthesized fragment and expulsion of the RNA and DNA segment. Synthesis occurs in 3 phases with two different polymerases, DNA polymerase α-primase and DNA polymerase δ. This process starts with polymerase α-primase displacing from the RNA and DNA primer by the clamp loader replication Effect, this Effect leads the sliding clamp onto the DNA. After this, DNA polymerase δ begins to go into its holoenzyme form which then synthesis begins. The synthesis process will continue until the 5’end of the previous Okazaki fragment has arrived. Once arrived, Okazaki fragment processing proceeds to join the newly synthesized fragment to the lagging strand. Last function of DNA polymerase δ is to serve as a supplement to FEN1/RAD27 5’ Flap Endonuclease activity. The rad27-p allele is lethal in most combinations but was viable with the rad27-p polymerase and exo1. Both rad27-p polymerase and exo1 portray strong synergistic increases in CAN 1 duplication mutations. The only reason this mutation is viable is due to the double-strand break repair genes RAD50, RAD51 and RAD52. The RAD27/FEN1 creates nicks between adjacent Okazaki fragments by minimizing the amount of strand-expulsion in the lagging strand.


title: Okazaki fragments

text: During lagging strand synthesis, DNA ligase I connects the Okazaki fragments, following replacement of the RNA primers with DNA nucleotides by DNA polymerase δ. Okazaki fragments that are not ligated could cause double-strand-breaks, which cleaves the DNA. Since only a small number of double-strand breaks are tolerated, and only a small number can be repaired, enough ligation failures could be lethal to the cell.


title: Okazaki fragments

text: Further research implicates the supplementary role of proliferating cell nuclear antigen (PCNA) to DNA ligase I's function of joining Okazaki fragments. When the PCNA binding site on DNA ligase I is inactive, DNA ligase I's ability to connect Okazaki fragments is severely impaired. Thus, a proposed mechanism follows: after a PCNA-DNA polymerase δ complex synthesizes Okazaki fragments, the DNA polymerase δ is released. Then, DNA ligase I binds to the PCNA, which is clamped to the nicks of the lagging strand, and catalyzes the formation of phosphodiester bonds.


title: Okazaki fragments

text: Flap endonuclease 1 (FEN1) is responsible for processing Okazaki fragments. It works with DNA polymerase to remove the RNA primer of an Okazaki fragment and can remove the 5' ribonucleotide and 5' flaps when DNA polymerase displaces the strands during lagging strand synthesis. The removal of these flaps involves a process called nick translation and creates a nick for ligation. Thus, FEN1's function is necessary to Okazaki fragment maturation in forming a long continuous DNA strand. Likewise, during DNA base repair, the damaged nucleotide is displaced into a flap and subsequently removed by FEN1.


title: Okazaki fragments

text: Dna2 endonuclease does not have a specific structure and their properties are not well characterized, but could be referred as single-stranded DNA with free ends (ssDNA). Dna2 endonuclease is essential to cleave long DNA flaps that leave FEN1 during the Okazaki Process. Dna2 endonuclease is responsible for the removal of the initiator RNA segment on Okazaki Fragments. Also, Dna2 endonuclease has a pivotal role in the intermediates created during diverse DNA metabolisms and is functional in telomere maintenance.


title: Okazaki fragments

text: Dna2 endonuclease becomes active when a terminal RNA segment attaches at the 5’ end, because it translocates in the 5’ to 3’ direction. In the presence of a single stranded DNA-binding protein RPA, the DNA 5' flaps become too long, and the nicks no longer fit as substrate for FEN1. This prevents the FEN1 from removing the 5′-flaps. Thus, Dna2's role is to reduce the 3′ end of these fragments, making it possible for FEN1 to cut the flaps, and the Okazaki fragment maturation more efficient. During the Okazaki Process, Dna2 helicase and endonuclease are inseparable. Dna2 Endonuclease does not depend on the 5’-tailed fork structure of its activity. Unproductive binding has been known to create blocks to FEN1 cleavage and tracking. It is known that ATP reduces activity, but promotes the release of the 3’-end label. Studies have suggested that a new model of Dna2 Endonuclease and FEN1 are partially responsible in Okazaki fragment maturation.


title: Okazaki fragments

text: Newly synthesized DNA, otherwise known as Okazaki fragments, are bound by DNA ligase, which forms a new strand of DNA. There are two strands that are created when DNA is synthesized. The leading strand is continuously synthesized and is elongated during this process to expose the template that is used for the lagging strand (Okazaki fragments). During the process of DNA replication, DNA and RNA primers are removed from the lagging strand of DNA to allow Okazaki fragments to bind to. Since this process is so common, Okazaki maturation will take place around a million times during one completion of DNA replication. For Okazaki maturation to occur, RNA primers must create segments on the fragments to be ligated. This is used as a building block for the synthesis of DNA in the lagging strand. On the template strand, polymerase will synthesize in the opposite direction from the replication fork. Once the template becomes discontinuous, it will create an Okazaki fragment. Defects in the maturation of Okazaki fragments can potentially cause strands in the DNA to break and cause different forms of chromosome abnormality. These mutations in the chromosomes can affect the appearance, the number of sets, or the number of individual chromosomes. Since chromosomes are fixed for each specific species, it can also change the DNA and cause defects in the genepool of that species.


title: Okazaki fragments

text: Okazaki fragments are present in both prokaryotes and eukaryotes. DNA molecules in eukaryotes differ from the circular molecules of prokaryotes in that they are larger and usually have multiple origins of replication. This means that each eukaryotic chromosome is composed of many replicating units of DNA with multiple origins of replication. In comparison, prokaryotic DNA has only a single origin of replication. In eukaryotes, these replicating forks, which are numerous all along the DNA, form "bubbles" in the DNA during replication. The replication fork forms at a specific point called autonomously replicating sequences (ARS). Eukaryotes have a clamp loader complex and a six-unit clamp called the proliferating cell nuclear antigen. The efficient movement of the replication fork also relies critically on the rapid placement of sliding clamps at newly primed sites on the lagging DNA strand by ATP-dependent clamp loader complexes. This means that the piecewise generation of Okazaki fragments can keep up with the continuous synthesis of DNA on the leading strand. These clamp loader complexes are characteristic of all eukaryotes and separate some of the minor differences in the synthesis of Okazaki fragments in prokaryotes and eukaryotes.


title: Okazaki fragments

text: The lengths of Okazaki fragments in prokaryotes and eukaryotes are different as well. Prokaryotes have Okazaki fragments that are quite longer than those of eukaryotes. Eukaryotes typically have Okazaki fragments that are 100 to 200 nucleotides long, whereas fragments in prokaryotic "E. coli" can be 2,000 nucleotides long. The reason for this discrepancy is unknown.


title: Okazaki fragments

text: Each eukaryotic chromosome is composed of many replicating units of DNA with multiple origins of replication. In comparison, the prokaryotic E. coli chromosome has only a single origin of replication. Replication in prokaryotes occurs inside of the cytoplasm, and this all begins the replication that is formed of about 100 to 200 or more nucleotides. Eukaryotic DNA molecules have a significantly larger number of replicons, about 50,000 or more; however, replication does not occur at the same time on all of the replicons. In eukaryotes, DNA replication takes place in the nucleus. A plethora replication form in just one replicating DNA molecule, the start of DNA replication is moved away by the multi-subunit protein. This replication is slow, and sometimes about 100 nucleotides per second are added.


title: Okazaki fragments

text: We take from this that prokaryotic cells are simpler in structure, they have no nucleus, organelles, and very little of DNA, in the form of a single chromosome. Eukaryotic cells have nucleus with multiple organelles and more DNA arranged in linear chromosomes. We also see that the size is another difference between these prokaryotic and eukaryotic cells. The average eukaryotic cell has about 25 times more DNA than a prokaryotic cell does. Replication occurs much faster in prokaryotic cells than in eukaryotic cells; bacteria sometimes only take 40 minutes, while animal cells can take up to 400 hours. Eukaryotes also have a distinct operation for replicating the telomeres at the end of their last chromosomes. Prokaryotes have circular chromosomes, causing no ends to synthesize. Prokaryotes have a short replication process that occurs continuously; eukaryotic cells, on the other hand, only undertake DNA replication during the S-phase of the cell cycle.


title: Okazaki fragments

text: The similarities are the steps for the DNA replication. In both prokaryotes and eukaryotes, replication is accomplished by unwinding the DNA by an enzyme called the DNA helicase. New strands are created by enzymes called DNA polymerases. Both of these follow a similar pattern, called semi-conservative replication, in which individual strands of DNA are produced in different directions, which makes a leading and lagging strand. These lagging strands are synthesized by the production of Okazaki fragments that are soon joined. Both of these organisms begin new DNA strands which also include small strands of RNA.


title: Okazaki fragments

text: Although cells undergo multiple steps in order to ensure there are no mutations in the genetic sequence, sometimes specific deletions and other genetic changes during Okazaki fragment maturation go unnoticed. Because Okazaki fragments are the set of nucleotides for the lagging strand, any alteration including deletions, insertions, or duplications from the original strand can cause a mutation if it is not detected and fixed. Other causes of mutations include problems with the proteins that aid in DNA replication. For example, a mutation related to primase affects RNA primer removal and can make the DNA strand more fragile and susceptible to breaks. Another mutation concerns polymerase α, which impairs the editing of the Okazaki fragment sequence and incorporation of the protein into the genetic material. Both alterations can lead to chromosomal aberrations, unintentional genetic rearrangement, and a variety of cancers later in life.


title: Okazaki fragments

text: In order to test the effects of the protein mutations on living organisms, researchers genetically altered lab mice to be homozygous for another mutation in protein related to DNA replication, flap endonuclease 1, or FEN1. The results varied based on the specific gene alterations. The homozygous knockout mutant mice experienced a "failure of cell proliferation" and "early embryonic lethality" (27). The mice with the mutation F343A and F344A (also known as FFAA) died directly after birth due to complications in birth including pancytopenia and pulmonary hypoplasia. This is because the FFAA mutation prevents the FEN1 from interacting with PCNA (proliferating cell nuclear antigen), consequently not allowing it to complete its purpose during Okazaki fragment maturation. The interaction with this protein is considered to be the key molecular function in the FEN1's biological function. The FFAA mutation causes defects in RNA primer removal and long-base pair repair, of which cause many breaks in the DNA. Under careful observation, cells homozygous for FFAA FEN1 mutations seem to display only partial defects in maturation, meaning mice heterozygous for the mutation would be able to survive into adulthood, despite sustaining multiple small nicks in their genomes. Inevitably however, these nicks prevent future DNA replication because the break causes the replication fork to collapse and causes double strand breaks in the actual DNA sequence. In time, these nicks also cause full chromosome breaks, which could lead to severe mutations and cancers. Other mutations have been implemented with altered versions of Polymerase α, leading to similar results.


title: Australian megafauna

text: The term Australian megafauna refers to the megafauna in Australia during the Pleistocene Epoch. Most of these species became extinct during the latter half of the Pleistocene, and the roles of human and climatic factors in their extinction are contested.


title: Australian megafauna

text: There are similarities between the prehistoric Australian megafauna and some mythical creatures from the Aboriginal Dreamtime.


title: Australian megafauna

text: Many modern researchers, including Tim Flannery, think that with the arrival of early Aboriginal Australians (around 70,000~65,000 years ago), hunting and the use of fire to manage their environment may have contributed to the extinction of the megafauna. Increased aridity during peak glaciation (about 18,000 years ago) may have also contributed, but most of the megafauna were already extinct by this time. Others, including Steve Wroe, note that records in the Australian Pleistocene are rare, and there is not enough data to definitively determine the time of extinction of many of the species, with many of the species having no confirmed record within the last 100,000 years. They suggest that many of the extinctions had been staggered over the course of the late Middle Pleistocene and early Late Pleistocene, prior to human arrival, due to climatic stress.


title: Australian megafauna

text: New evidence based on accurate optically stimulated luminescence and uranium-thorium dating of megafaunal remains suggests that humans were the ultimate cause of the extinction for some of the megafauna in Australia. The dates derived show that all forms of megafauna on the Australian mainland became extinct in the same rapid timeframe—approximately 46,000 years ago—the period when the earliest humans first arrived in Australia (around 70,000~65,000 years ago long chronology and 50,000 years ago short chronology). However, these results were subsequently disputed, with another study showing that 50 of 88 megafaunal species have no dates postdating the penultimate glacial maxiumum around 130,000 years ago, and there was only firm evidence for overlap of 8-14 megafaunal species with people. Analysis of oxygen and carbon isotopes from teeth of megafauna indicate the regional climates at the time of extinction were similar to arid regional climates of today and that the megafauna were well adapted to arid climates. The dates derived have been interpreted as suggesting that the main mechanism for extinction was human burning of a landscape that was then much less fire-adapted; oxygen and carbon isotopes of teeth indicate sudden, drastic, non-climate-related changes in vegetation and in the diet of surviving marsupial species. However, early Aboriginal peoples appear to have rapidly eliminated the megafauna of Tasmania about 41,000 years ago (following formation of a land bridge to Australia about 43,000 years ago as Ice Age sea levels declined) without using fire to modify the environment there, implying that at least in this case hunting was the most important factor. It has also been suggested that the vegetational changes that occurred on the mainland were a consequence, rather than a cause, of the elimination of the megafauna. This idea is supported by sediment cores from Lynch's Crater in Queensland, which suggest that fire increased in the local ecosystem about a century after the disappearance of "Sporormiella ("a fungus found in herbivorous animal dung used as a megafaunal proxy), leading to a subsequent transition to fire-tolerant sclerophyll vegetation. However, the use of "Sporormiella" as a megafaunal proxy has been criticised, noting that "Sporormiella" is found sporadically in the dung of various herbivorous species, including extant emus and kangaroos, not just megafauna, that its presence depends on a variety of factors, often unrelated to megafaunal abundance, and that in Cuddie Springs, a well known megafaunal site, the densities of "Sporormiella" were consistently low. A study of extinct megafauna at the Walker Creek site in Queensland, found that their disappearance from the site after 40 kya came after an extended period of environmental deterioration.


title: Australian megafauna

text: Chemical analysis of fragments of eggshells of "Genyornis newtoni", a flightless bird that became extinct in Australia, from over 200 sites, revealed scorch marks consistent with cooking in human-made fires, presumably the first direct evidence of human contribution to the extinction of a species of the Australian megafauna. This was later contested by another study that noted the too small dimensions (126 x 97 mm, roughly like the emu eggs, while the moa eggs were about 240 mm) for the "Genyornis" supposed eggs, and rather, attributed them to another extinct, but much smaller bird, the megapode "Progura". The real time that saw "Genyornis" vanish is still an open question, but this was believed as one of the best documented megafauna extinctions in Australia.


title: Australian megafauna

text: "Imperceptive overkill"; a scenario where anthropogenic pressures take place; slowly and gradually wiping the megafauna out; has been suggested.


title: Australian megafauna

text: On the other hand, there is also evidence to suggest that (contrary to other conclusions) the megafauna lived alongside humans for several thousand years. The question of if (and how) the megafauna died before the arrival of humans is still debated; with some authors maintaining that only a minority of such fauna remained by the time the first humans settled on the mainland. One of the most important advocates of human role, Tim Flannery, author of the book "Future Eaters", was also heavily criticised for his conclusions. A surprisingly late date of 33-37 kya is known for a "Zygomaturus" specimen from the Willandra Lakes Region in New South Wales, the latest known date for any Australian Megafauna. This is well after aboriginal arrival in Australia around 50 kya.


title: Australian megafauna

text: A 2021 study found that the rate of extinction of Australia's megafauna is rather unusual, with some more generalistic species having gone extinct earlier while highly specialised ones having become extinct later or even still surviving today. A mosaic cause of extinction with different anthropogenic and environmental pressures was proposed.


title: Australian megafauna

text: The term "megafauna" is usually applied to large animals (over ). In Australia, however, megafauna were never as large as those found on other continents, and so a more lenient criterion of over is often applied.


title: Australian megafauna

text: The following is an incomplete list of extinct Australian megafauna (monotremes, marsupials, birds and reptiles) in the format:


title: Australian megafauna

text: The association was made at least as early as 1845, with colonists writing that Aboriginal people identified "Diprotodon" bones as belonging to bunyips, and Thomas Worsnop concluding that the fear of bunyip attacks at watering holes remembered a time when "Diprotodon" lived in marshes.


title: Australian megafauna

text: In the early 1900s, John Walter Gregory outlined the Kadimakara (or Kuddimurka or Kadimerkera) story of the Diyari (similar stories being told by nearby peoples), which describes the deserts of Central Australia as having once been "fertile, well-watered plains" with giant gum trees, and almost solid cloud cover overhead. The trees created a roof of vegetation in which lived the strange monsters called Kadimakara—which sometimes came to the ground to eat. One time, the gum trees were destroyed, forcing the Kadimakara to remain on the ground, particularly Lake Eyre and Kalamurina, until they died.


title: Australian megafauna

text: In times of drought and flood, the Diyari performed corroborees (including dances and blood sacrifices) at the bones of the Kadimakara to appease them and request that they intercede with the spirits of rain and clouds. Sites of Kadimakara bones identified by Aboriginal people corresponded with megafauna fossil sites, and an Aboriginal guide identified a "Diprotodon" jaw as belonging to the Kadimakara.


title: Australian megafauna

text: Gregory speculated that the story could be a remnant from when the Diyari lived elsewhere, or when the geographical conditions of Central Australia were different. The latter possibility would indicate Aboriginal coexistence with megafauna, with Gregory saying:


title: Australian megafauna

text: After examining fossils, Gregory concluded that the story was a combination of the two factors, but that the environment of Lake Eyre had probably not changed much since Aboriginal habitation. He concluded that while some references to Kadimakara were probably memories of the crocodiles once found in Lake Eyre, others that describe a "big, heavy land animal, with a single horn on its forehead" were probably references to "Diprotodon".


title: Australian megafauna

text: Geologist Michael Welland describes from across Australia Dreamtime "tales of giant creatures that roamed the lush landscape until aridity came and they finally perished in the desiccated marshes of Kati Thanda–Lake Eyre", giving as examples the Kadimakara of Lake Eye, as well as continent-wide stories of the Rainbow Serpent, which he says corresponds with "Wonambi naracoortensis".


title: Australian megafauna

text: Journalist Peter Hancock speculates in "The Crocodile That Wasn't" that a Dreamtime story from the Perth area could be a memory of "Varanus priscus". However, the story in question details dingoes attacking or frightening off the alleged "V. priscus", when the giant lizard died out nearly 46,000 years before the accepted arrival date of dingoes.


title: Australian megafauna

text: Rock art in the Kimberley region appears to depict a marsupial lion and a marsupial tapir, as does Arnhem land art. Arnhem art also appears to depict "Genyornis", a bird that is believed to have gone extinct 40,000 years ago.


title: Australian megafauna

text: An Early Triassic archosauromorph found in Queensland, "Kadimakara australiensis", is named after the Kadimakara.


title: Oliver's Army

text: "Oliver's Army" is a song written by Elvis Costello and performed by Costello and the Attractions, from the former's third studio album "Armed Forces" (1979). The song is a new wave track that was lyrically inspired by the Troubles in Northern Ireland and includes lyrics critical of the socio-economic components of war. Costello had travelled to Northern Ireland and was influenced by sights of British soldiers patrolling Belfast. Musically, the song features a glossy production and a keyboard performance inspired by ABBA, creating a juxtaposition between the lyrics and music that both critics and Costello have pointed out.


title: Oliver's Army

text: Released as the first single from "Armed Forces", "Oliver's Army" was Costello's most successful single in the United Kingdom, spending three weeks at number two on the UK Singles Chart and remaining on the chart for 12 weeks. The song also charted in New Zealand, the Netherlands, Ireland and Australia, and it spawned the successful follow-up single "Accidents Will Happen", which reached the top 30 in the UK.


title: Oliver's Army

text: "Oliver's Army" has since been recognised by writers as one of the highlights of "Armed Forces" and has received critical acclaim for its melody, production, and lyrics. The song has appeared on numerous rankings of Costello's great songs as well as on multiple compilation albums. It has been covered by multiple artists, including Blur.


title: Oliver's Army

text: Costello wrote "Oliver's Army" as a comment on the Troubles in Northern Ireland during the 1970s. He was inspired to write the song after seeing British soldiers patrolling the streets of Belfast. He stated, "I made my first trip to Belfast in 1978 and saw mere boys walking around in battle dress with automatic weapons. They were no longer just on the evening news. These snapshot experiences exploded into visions of mercenaries and imperial armies around the world. The song was based on the premise 'they always get a working class boy to do the killing'". Costello's family had roots in the Northern Ireland conflict; as his father, Ross McManus, recalled, Oliver's Army' is an important track for me... My grandfather was an Ulster Catholic, and as a child, I lived in an area where bigotry was rife". Costello's Irish grandfather, Pat McManus, had served as a British soldier during World War I and the Easter Rising.


title: Oliver's Army

text: According to "Sound on Sound", the title "Oliver" refers to English statesman Oliver Cromwell, who personally led the Parliamentarian forces which conquered Ireland in 1649. In addition to the Troubles in Northern Ireland, the song references other "imperialist battles" in Hong Kong, Palestine and South Africa. However, Costello later explained that the song was not intended to be a comprehensive political piece; he said "It wasn't supposed to read like a coherent political argument. It was pop music". He also pointed out that the opening lyrics "argued the absurdity of even trying to write about such a complex subject".


title: Oliver's Army

text: The song lyrics contain the phrase "white nigger", a racial slur which usually remains uncensored on radio stations. The usage of the phrase came under scrutiny, particularly after Costello used racial slurs during a drunken argument with Stephen Stills and Bonnie Bramlett in 1979. The same year, Costello's father published a letter in "Rolling Stone" defending his son against accusations of racism, stating "Nothing could be further from the truth. My own background has meant that I am passionately opposed to any form of prejudice based on religion or race...His mother comes from the tough multiracial area of Liverpool, and I think she would still beat the tar out of him if his orthodoxy were in doubt".


title: Oliver's Army

text: In March 2013, the radio station BBC Radio 6 Music played the song with the phrase removed, despite BBC radio stations having played the song uncensored for over 30 years. This decision attracted public criticism, with critics citing the intended anti-racist and anti-war theme of the single. In January 2022, Costello said that he would no longer be performing the song and asked that radio stations no longer play it. In an interview on Australian radio around the same time, Costello clarified he didn't specifically ask radio stations to stop playing the song, but he did state that the way some radio stations edited or bleeped the phrase called attention to the phrase without engaging the context in which it was written.


title: Oliver's Army

text: Dubbed "a 45 that radio could hardly refuse" by AllMusic's Mark Deming, "Oliver's Army" is a new wave song with a radio-friendly arrangement that has been described as "glossy". Deming noted the "pop-friendly production" and Costello's "almost jubilant-sounding vocal [distinct] from the traditionally dour (or threatening) Costello, who even embellished himself with some tight vocal harmony overdubs". The song was noted for keyboardist Steve Nieve's "buoyant" piano part, which was inspired by ABBA's 1976 hit single "Dancing Queen". Nieve has explicitly acknowledged the influence.


title: Oliver's Army

text: Many critics have made note of the juxtaposition between the song's music and lyrics; Jim Beviglia of "American Songwriter" said that Oliver's Army' heap[s] bucketfuls of the sweet stuff all over the instrumental arrangement to make sure his acerbic lyrics would get the audience they deserved", while Deming described the song as part of Costello's "most pungently political set of songs up to that time, but wrapped them in catchy melodies...that gave Elvis the Menace a real chance at cracking the singles charts in America". Janet Maslin of "Rolling Stone", summarizing the song's multiple dimensions, wrote, "You can hear it one way, or the other way, or both. Elvis Costello doesn't seem to give a damn what you do, and that’s no small part of his charm".


title: Oliver's Army

text: Costello later said "I don't think [the song's] success was because of the lyrics. I always liked the idea of a bright pop tune that you could be singing along to for ages before you realize what it is you're actually singing. Of course, the downside of that is some people only hear the tune and never listen to the words. After a while, I got frustrated at that".


title: Oliver's Army

text: "Oliver's Army" was first performed at the 1978 Roskilde Festival. At the time, the song was not seen as a potential hit. Bassist Bruce Thomas later said, "I wasn't particularly aware that that was going to be our anthemic song...It's hard to tell". Costello expected that the song would be used as a B-side. According to Costello, he was "about to scrap" the track until producer Nick Lowe convinced him to finish recording the song. However, the song was completed to be released on Costello's "Armed Forces" (1979).


title: Oliver's Army

text: "Oliver's Army" was released as the debut single from "Armed Forces" on 2 February 1979, backed with Costello's rendition of the 1937 show-tune "My Funny Valentine". The single became a commercial hit in the UK, reaching number two over a chart stay of 12 weeks, and remains Costello's most successful UK single release. Costello never reached number one in the UK. "Oliver's Army" was also a hit in other countries, reaching number 4 in Ireland, number 24 in Australia, and number 25 in New Zealand. However, the song failed to chart in the United States despite radio airplay and the success of "Armed Forces" in the U.S. The follow-up single "Accidents Will Happen" also saw commercial success, charting at number 28 in the United Kingdom.


title: Oliver's Army

text: A music video for "Oliver's Army" directed by Chuck Statler was released to accompany the song. Filmed in Hawaii while Costello and the Attractions were on tour, the video was shot at 4:00 a.m. in a strip club after the band could not find another location. It aired on MTV's first US broadcast day on .


title: Oliver's Army

text: As a result of the huge success of the single, Costello felt insecure about the relationship he had with his audience, particularly those who only recognised "Oliver's Army". He said, "I saw people responding without any kind of understanding or consideration. We'd play a set where we'd play brilliantly all night and then we'd do our hit single and people would go crazy. Yet they would be bewildered by the rest of what we were doing".


title: Oliver's Army

text: "Oliver's Army" has since been released on multiple compilation albums, including "The Best of Elvis Costello and the Attractions", "Girls Girls Girls", and "The Very Best of Elvis Costello".


title: Oliver's Army

text: "Oliver's Army" has attracted positive reviews from music critics. In 1979, Geoffrey Himes of "The Washington Post" praised the "compressed drama" of "Oliver's Army", along with all the other tracks on "Armed Forces", and highlighted the song's lyrics, despite calling it "almost a direct steal from Spector's hit with the Ronettes, 'Baby, I Love You'". Maslin called the track the "pièce de résistance" of "Armed Forces" and praised the contrast between the song's music and lyrics. Douglas Wolk of "Blender Magazine" named the song as one of the key tracks from "Armed Forces" to download, while Matt LeMay of Pitchfork Media called the song "stunning". Author Graeme Thomson called the track the "pinnacle of Elvis' ability to be all things to all people" and praised the way Costello "melded serious lyrics to insanely catchy pop".


title: Oliver's Army

text: The song has since been rated in numerous rankings as one of Costello's better songs. "The Daily Telegraph"s Martin Chilton ranked the song number one on his top 40 list of best Costello songs, calling it a "catchy tune with powerful lyrics". Jeremy Allen of "The Guardian" named the song one of the 10 best Elvis Costello songs, describing the song as "so smart and subversive that many were unaware it was a protest song at all" and comparing it positively against Costello’s eventual writing partner Paul McCartney's 1971 protest song "Give Ireland Back to the Irish". Ryan J. Prado of "Paste" ranked the song Costello's ninth best and said that "the song is great no matter how thinly you spread its political agendas". Beviglia named the song Costello's 12th best, and Brian Hyatt of "Entertainment Weekly" named it one of his top 10 Costello songs. "The Redditch Standard" named it Costello's top song.


title: Oliver's Army

text: For most of Costello's career — until January 2022, when he announced his decision to stop performing the song — "Oliver's Army" remained a mainstay of his live setlist; Thomson described the song as an "old crowd pleaser". Shortly after its release, Costello and the Attractions performed the song on television programmes for promotion. In a piece for "The Guardian", Costello mocked his dress from a performance of the song on "the Kenny Everett Video Show", recalling "During my 'Pop Star Period: 1978-79' I was a fashion disaster of checkerboard eyestrain. I wore powder-blue and pink suits, turquoise lamé jackets and pointy red leather Chelsea boots, but I usually appeared pretty glassy-eyed and shiny under the hot studio lights. No wonder the girls all swooned". Referencing his performance of "Oliver's Army" on "Top of the Pops", Costello sardonically wrote, "Checkerboard jacket alert..."


title: Oliver's Army

text: Costello performed "Oliver's Army", along with other political songs, as part of a 9 March 1984 protest concert against Margaret Thatcher during the 1984–85 mining strike. "Oliver's Army" was also performed at the 2013 Glastonbury Festival.


title: Oliver's Army

text: Britpop band Blur recorded a version of the song for "Peace Together", a compilation album released in 1993 to promote peace in Northern Ireland. OK Go released a cover on their 2014 rarity album "The Compleat 12 Months of (Rare, Unreleased) OK Go", while Cannon and Ball released a version on their 1980 album "Rock On Tommy". Comedian Frank Skinner performed the song when he impersonated Costello on a celebrity edition of "Stars in Their Eyes" in 1999, the mention of "nigger" replaced with "figure". Belle and Sebastian performed a live version of the song at a 2005 concert in Perth.


title: Oliver's Army

text: "Oliver's Army" has been performed by the original version's producer Nick Lowe, who sang the song at an event at the Great American Music Hall in 2010. The performance was part of an event titled "Costello Sings Lowe, Nick Sings Elvis – A Rare Bashing of Each Other's Songs", where Lowe and Costello performed each other's songs.


title: Sandy Helberg

text: Helberg was born in Frankfurt, Germany, the son of Tonia (née Altman) and Sam Helberg. His parents were both Holocaust survivors from German-occupied Poland, who met in a concentration camp. They emigrated to the United States in 1950, where his father, originally a barber, eventually became a real estate developer in Toledo, Ohio, where Sandy and his brothers Ted and Tom were raised.


title: Sandy Helberg

text: Helberg relocated to New York City and studied acting with Sanford Meisner at the Neighborhood Playhouse. He performed stand-up comedy and was part of an improv group that appeared in clubs in Greenwich Village. He later moved to Los Angeles, becoming an original member of the Los Angeles improv group, The Groundlings. Acting in several comedy films, in particular three Mel Brooks films "High Anxiety," "History of the World, Part I," and "Spaceballs", he starred in the comedy films "The Hollywood Knights" and "Up the Creek."


title: Sandy Helberg

text: Helberg wrote and starred in the short-lived 1977 syndicated TV series "The Lorenzo and Henrietta Music Show" and the 1979 CBS TV series "Flatbush". He has made numerous guest appearances on TV shows, including "Trapper John, M.D.", "Remington Steele", "Newhart", "The Jeffersons", "M*A*S*H", "Married... with Children", "The Wonder Years", "Night Court", "Fernwood 2 Night", "Knight Rider", "Too Close for Comfort", "Get a Life", "House Calls", "Cybill", and "Days of Our Lives" among others.


title: Sandy Helberg

text: Helberg co-starred in the NBC miniseries, "79 Park Avenue", and a CBS movie of the week, "More Wild Wild West." He played Yeoman Purser Burl "Gopher" Smith in "The Love Boat" pilot; however, when it became an ABC television series, Fred Grandy took over the role.


title: Sandy Helberg

text: Helberg and his wife Harriet wrote episodes for such television series as "The Golden Girls", "Perfect Strangers", "Dear John", and "Harry and the Hendersons". He also co-produced "USO Salute to the Troops" for HBO/TBS.


title: Sandy Helberg

text: Helberg has been married to Harriet Birnbaum, a casting director, since 1975 and has two sons, Mason and actor Simon.


title: Sandy Helberg

text: Sandy and Harriet adopted their granddaughter, Lily Rose Helberg, at four months old. Lily was born May 12, 2016.


title: X-ray tube

text: An X-ray tube is a vacuum tube that converts electrical input power into X-rays. The availability of this controllable source of X-rays created the field of radiography, the imaging of partly opaque objects with penetrating radiation. In contrast to other sources of ionizing radiation, X-rays are only produced as long as the X-ray tube is energized. X-ray tubes are also used in CT scanners, airport luggage scanners, X-ray crystallography, material and structure analysis, and for industrial inspection.


title: X-ray tube

text: Increasing demand for high-performance Computed tomography (CT) scanning and angiography systems has driven development of very high performance medical X-ray tubes.


title: X-ray tube

text: X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered on November 8, 1895, by the German physicist Wilhelm Conrad Röntgen. These first generation "cold cathode" or "Crookes" X-ray tubes were used until the 1920s. The Crookes tube was improved by William Coolidge in 1913. The Coolidge tube, also called hot cathode tube, is the most widely used. It works with a very good quality vacuum (about 10 Pa, or 10 Torr).


title: X-ray tube

text: Until the late 1980s, X-ray generators were merely high-voltage, AC to DC variable power supplies. In the late 1980s a different method of control was emerging, called high speed switching. This followed the electronics technology of switching power supplies (aka switch mode power supply), and allowed for more accurate control of the X-ray unit, higher quality results, and reduced X-ray exposures.


title: X-ray tube

text: As with any vacuum tube, there is a cathode, which emits electrons into the vacuum and an anode to collect the electrons, thus establishing a flow of electrical current, known as the beam, through the tube. A high voltage power source, for example 30 to 150 kilovolts (kV), called the "tube voltage", is connected across cathode and anode to accelerate the electrons. The X-ray spectrum depends on the anode material and the accelerating voltage.


title: X-ray tube

text: Electrons from the cathode collide with the anode material, usually tungsten, molybdenum or copper, and accelerate other electrons, ions and nuclei within the anode material. About 1% of the energy generated is emitted/radiated, usually perpendicular to the path of the electron beam, as X-rays. The rest of the energy is released as heat. Over time, tungsten will be deposited from the target onto the interior surface of the tube, including the glass surface. This will slowly darken the tube and was thought to degrade the quality of the X-ray beam. Vaporized tungsten condenses on the inside of the envelope over the "window" and thus acts as an additional filter and decreases the tube's ability to radiate heat. Eventually, the tungsten deposit may become sufficiently conductive that at high enough voltages, arcing occurs. The arc will jump from the cathode to the tungsten deposit, and then to the anode. This arcing causes an effect called "crazing" on the interior glass of the X-ray window. As time goes on, the tube becomes unstable even at lower voltages, and must be replaced. At this point, the tube assembly (also called the "tube head") is removed from the X-ray system, and replaced with a new tube assembly. The old tube assembly is shipped to a company that reloads it with a new X-ray tube.


title: X-ray tube

text: The X-ray photon-generating effect is generally called the bremsstrahlung effect, a compound of the German "bremsen" meaning to brake, and "Strahlung" meaning radiation.


title: X-ray tube

text: The range of photonic energies emitted by the system can be adjusted by changing the applied voltage, and installing aluminum filters of varying thicknesses. Aluminum filters are installed in the path of the X-ray beam to remove "soft" (non-penetrating) radiation. The number of emitted X-ray photons, or dose, are adjusted by controlling the current flow and exposure time.


title: X-ray tube

text: Heat is produced in the focal spot of the anode. Since a small fraction (less than or equal to 1%) of electron energy is converted to X-rays, it can be ignored in heat calculations.


title: X-ray tube

text: Heat Unit (HU) was used in the past as an alternative to Joule. It is a convenient unit when a single-phase power source is connected to the X-ray tube. With a full-wave rectification of a sine wave, formula_2=formula_7, thus the heat unit:


title: X-ray tube

text: Crookes tubes generated the electrons needed to create X-rays by ionization of the residual air in the tube, instead of a heated filament, so they were partially but not completely evacuated. They consisted of a glass bulb with around 10 to 5×10 atmospheric pressure of air (0.1 to 0.005 Pa). They had an aluminum cathode plate at one end of the tube, and a platinum anode target at the other end. The anode surface was angled so that the X-rays would radiate through the side of the tube. The cathode was concave so that the electrons were focused on a small (~1 mm) spot on the anode, approximating a point source of X-rays, which resulted in sharper images. The tube had a third electrode, an anticathode connected to the anode. It improved the X-ray output, but the method by which it achieved this is not understood. A more common arrangement used a copper plate anticathode (similar in construction to the cathode) in line with the anode such that the anode was between the cathode and the anticathode.


title: X-ray tube

text: To operate, a DC voltage of a few kilovolts to as much as 100 kV was applied between the anodes and the cathode, usually generated by an induction coil, or for larger tubes, an electrostatic machine.


title: X-ray tube

text: Crookes tubes were unreliable. As time passed, the residual air would be absorbed by the walls of the tube, reducing the pressure. This increased the voltage across the tube, generating 'harder' X-rays, until eventually the tube stopped working. To prevent this, 'softener' devices were used (see picture). A small tube attached to the side of the main tube contained a mica sleeve or chemical that released a small amount of gas when heated, restoring the correct pressure.


title: X-ray tube

text: In the Coolidge tube, the electrons are produced by thermionic effect from a tungsten filament heated by an electric current. The filament is the cathode of the tube. The high voltage potential is between the cathode and the anode, the electrons are thus accelerated, and then hit the anode.


title: X-ray tube

text: There are two designs: end-window tubes and side-window tubes. End window tubes usually have "transmission target" which is thin enough to allow X-rays to pass through the target (X-rays are emitted in the same direction as the electrons are moving.) In one common type of end-window tube, the filament is around the anode ("annular" or ring-shaped), the electrons have a curved path (half of a toroid).


title: X-ray tube

text: What is special about side-window tubes is an electrostatic lens is used to focus the beam onto a very small spot on the anode. The anode is specially designed to dissipate the heat and wear resulting from this intense focused barrage of electrons. The anode is precisely angled at 1-20 degrees off perpendicular to the electron current so as to allow the escape of some of the X-ray photons which are emitted perpendicular to the direction of the electron current. The anode is usually made out of tungsten or molybdenum. The tube has a window designed for escape of the generated X-ray photons.


title: X-ray tube

text: A considerable amount of heat is generated in the focal spot (the area where the beam of electrons coming from the cathode strike to) of a stationary anode. Rather, a rotating anode lets the electron beam sweep a larger area of the anode, thus redeeming the advantage of a higher intensity of emitted radiation, along with reduced damage to the anode compared to its stationary state.


title: X-ray tube

text: The focal spot temperature can reach during an exposure, and the anode assembly can reach following a series of large exposures. Typical anodes are a tungsten-rhenium target on a molybdenum core, backed with graphite. The rhenium makes the tungsten more ductile and resistant to wear from the impact of the electron beams. The molybdenum conducts heat from the target. The graphite provides thermal storage for the anode, and minimizes the rotating mass of the anode.


title: X-ray tube

text: Some X-ray examinations (such as, e.g., non-destructive testing and 3-D microtomography) need very high-resolution images and therefore require X-ray tubes that can generate very small focal spot sizes, typically below 50 μm in diameter. These tubes are called microfocus X-ray tubes.


title: X-ray tube

text: Solid-anode microfocus X-ray tubes are in principle very similar to the Coolidge tube, but with the important distinction that care has been taken to be able to focus the electron beam into a very small spot on the anode. Many microfocus X-ray sources operate with focus spots in the range 5-20 μm, but in the extreme cases spots smaller than 1 μm may be produced.


title: X-ray tube

text: The major drawback of solid-anode microfocus X-ray tubes is the very low power they operate at. In order to avoid melting of the anode the electron-beam power density must be below a maximum value. This value is somewhere in the range 0.4-0.8 W/μm depending on the anode material. This means that a solid-anode microfocus source with a 10 μm electron-beam focus can operate at a power in the range 4-8 W.


title: X-ray tube

text: In metal-jet-anode microfocus X-ray tubes the solid metal anode is replaced with a jet of liquid metal, which acts as the electron-beam target. The advantage of the metal-jet anode is that the maximum electron-beam power density is significantly increased. Values in the range 3-6 W/μm have been reported for different anode materials (gallium and tin). In the case with a 10 μm electron-beam focus a metal-jet-anode microfocus X-ray source may operate at 30-60 W.


title: X-ray tube

text: The major benefit of the increased power density level for the metal-jet X-ray tube is the possibility to operate with a smaller focal spot, say 5 μm, to increase image resolution and at the same time acquire the image faster, since the power is higher (15-30 W) than for solid-anode tubes with 10 μm focal spots.


title: X-ray tube

text: Any vacuum tube operating at several thousand volts or more can produce X-rays as an unwanted byproduct, raising safety issues. The higher the voltage, the more penetrating the resulting radiation and the more the hazard. CRT displays, once common in color televisions and computer displays, operate at depending on size, making them the main concern among household appliances. Historically, concern has focused less on the cathode ray tube, since its thick glass envelope is impregnated with several pounds of lead for shielding, than on high voltage (HV) rectifier and voltage regulator tubes inside earlier TVs. In the late 1960s it was found that a failure in the HV supply circuit of some General Electric TVs could leave excessive voltages on the regulator tube, causing it to emit X-rays. The models were recalled and the ensuing scandal caused the US agency responsible for regulating this hazard, the Center for Devices and Radiological Health of the Food and Drug Administration (FDA), to require that all TVs include circuits to prevent excessive voltages in the event of failure. The hazard associated with excessive voltages was eliminated with the advent of all-solid-state TVs, which have no tubes other than the CRT. Since 1969, the FDA has limited TV X-ray emission to 0.5 mR (milliroentgen) per hour. With the switch from CRTs to other screen technologies starting in the 1990s, there are no vacuum tubes capable of emitting X-rays at all.


title: Ælfgifu of Northampton

text: Ælfgifu of Northampton (, 990 – after 1036) was the first wife of Cnut the Great, King of England and Denmark, and mother of Harold Harefoot, King of England. She was regent of Norway from 1030 to 1035.


title: Ælfgifu of Northampton

text: Ælfgifu was born into an important noble family based in the Midlands (Mercia). She was a daughter of Ælfhelm, ealdorman of southern Northumbria, and his wife Wulfrun. Ælfhelm was killed in 1006, probably at the command of King Æthelred the Unready, and Ælfgifu's brothers, Ufegeat and Wulfheah, were blinded. Wulfric Spot, a wealthy nobleman and patron of Burton Abbey, was the brother of Ælfhelm or Wulfrune. The family again came under suspicion during the invasion of England by Swein Forkbeard, King of Denmark, in 1013–14, and further members were charged with treachery and killed. It is possible that Ælfgifu was a kinswoman of the wife of Ælfgar, Earl of Mercia, also called Ælfgifu.


title: Ælfgifu of Northampton

text: When Swein invaded, northern peoples, many of them of Scandinavian descent, immediately submitted to him. He then married his young son Cnut to Ælfgifu to seal their loyalty. Swein went on to conquer the whole of England and was accepted as King, but he died in February 1014 after a reign of only five weeks. Æthelred then sent an army which forced Cnut to flee back to Denmark, and in the opinion of historian Ian Howard, he left his wife and their baby son, Svein, the future King of Norway, behind with her family. They were anxious to make their peace with Æthelred, but unwilling to hand Ælfgifu and her son over to Æthelred to be killed, so they sent the mother and child with King Swein's body to Denmark. There she became pregnant again, and in 1015 or 1016 she gave birth to Harold Harefoot. In the period immediately following, she may have been given authority over some region of Denmark, perhaps that of a Danish-controlled area of the Baltic coastline.


title: Ælfgifu of Northampton

text: Her two sons were to figure prominently in the empire which their father built in northern Europe, though not without opposition. After his conquest of England in 1016, Cnut married Emma of Normandy, the widow of King Æthelred. It was then regarded as acceptable to put aside one wife and take another if the first wife was acquired through the non-Christian pagan ceremony of "handfasting" and nearly always for reasons of political advantage, a practice which might be described as "serial monogamy"; this was the case with the marriage of Ælfgifu to Cnut. The status of Cnut's two 'marriages' and their social context in England and Scandinavia has been discussed recently by Timothy Bolton. Emma's sons, Edward and Ælfred by Æthelred and Harthacnut by Cnut, were also claimants to the throne of her husband. Exactly how the second marriage affected Ælfgifu's status as Cnut's first consort is unknown, but there is no evidence to suggest that she was repudiated.


title: Ælfgifu of Northampton

text: After the defeat and death of Olaf II of Norway by forces loyal to Cnut, Cnut sent Ælfgifu with their eldest son Svein to rule Norway, in 1030. Their rule was, however, so harsh that the Norwegians rebelled against them. They were driven out, in 1034 or 1035, while Svein died of wounds in Denmark shortly after, probably in 1036. In Norway, where she was known as "Álfífa" in Old Norse, this period entered history as 'Álfífa's time'("Álfífuǫld"), remembered for her severe rule and heavy taxation. In the Norwegian "Ágrip", for instance, the following verse is attributed to her contemporary, the skald Sigvatr:


title: Ælfgifu of Northampton

text: Cnut died at Shaftesbury in 1035. Symeon of Durham and Adam of Bremen suggest that Cnut had reserved the English throne for Harold, while the "Encomium Emmae Reginae", written to defend Harthacnut's mother, Emma, claims that he had done so for Harthacnut. Ælfgifu was determined that her second son Harold should be the next English king. She had returned to England (at least) by 1036, while Emma's son Harthacnut was away in Denmark, at war with the Norwegian king Magnus I, and the Swedes under their king Anund Jacob. Emma's other sons, Ælfred and Edward, stayed in Normandy. With help from her supporters, Ælfgifu was able to secure the throne for her son. In the view of Frank Stenton, she was probably the real ruler of England for part, if not the whole, of his reign.


title: Ælfgifu of Northampton

text: The "Anglo-Saxon Chronicle" (versions C, D and E) describes how Harold and his men forcefully laid claim on the treasury housed in Winchester, where Cnut was buried and Emma (whom the Anglo-Saxons also referred to as "Ælfgifu" the queen) had taken up residence:


title: Ælfgifu of Northampton

text: Manuscript E, which is known for its Godwinist sympathies, adds a number of details, including the assembly at Oxford in 1037 at which Harold was elected king of England and the mustering of support north of the Thames, where the power base of Ælfgifu's family was concentrated.


title: Ælfgifu of Northampton

text: During 1036, opinion in England moved towards Harold. By August a report had reached Emma's daughter, Gunnhild, at the German court that her "unhappy and unjust step-mother" (i.e. Ælfgifu) was working to deprive Gunnhild's brother, Harthacnut, of the kingdom by holding great feasts, and trying by argument and gifts to persuade the leading nobles to give their fealty to Harold. Emma's encomiast attributes to her even more seriously dishonest methods. She makes Ælfgifu an accomplice in the murder of Emma's youngest son, Alfred, by suggesting that she was responsible for sending a forged letter to Normandy inviting Alfred to England. The "Encomium Emmae Reginae" also claimed that Ælfgifu's son Harold was a servant's son.


title: Ælfgifu of Northampton

text: Ælfgifu is not recorded after 1036, apart from a possible reference to her as the "lady", and it is not known when she died.


title: Garamond

text: Garamond is a group of many serif typefaces, named for sixteenth-century Parisian engraver Claude Garamond, generally spelled as Garamont in his lifetime. Garamond-style typefaces are popular and particularly often used for book printing and body text.


title: Garamond

text: Garamond's types followed the model of an influential typeface cut for Venetian printer Aldus Manutius by his punchcutter Francesco Griffo in 1495, and are in what is now called the old-style of serif letter design, letters with a relatively organic structure resembling handwriting with a pen, but with a slightly more structured, upright design.


title: Garamond

text: Following an eclipse in popularity in the eighteenth and nineteenth century, many modern revival faces in the Garamond style have been developed. It is common to pair these with italics based on those created by his contemporary Robert Granjon, who was well known for his proficiency in this genre. However, although Garamond himself remains considered a major figure in French printing of the sixteenth century, historical research has increasingly placed him in context as one artisan punchcutter among many active at a time of rapid production of new typefaces in sixteenth-century France, and research has only slowly developed into which fonts were cut by him and which by contemporaries; Robert Bringhurst commented that "it was a widespread custom for many years to attribute almost any good sixteenth-century French font" to Garamond. As a result, while "Garamond" is a common term in the printing industry, the terms "French Renaissance antiqua" and "Garalde" have been used in academic writing to refer generally to fonts on the Aldus-French Renaissance model by Garamond and others.


title: Garamond

text: In particular, many 'Garamond' revivals of the early twentieth century are actually based on the work of a later punchcutter, Jean Jannon, whose noticeably different work was for some years misattributed to Garamond. The most common digital font named Garamond is Monotype Garamond. Developed in the early 1920s and bundled with Microsoft Office, it is a revival of Jannon's work.


title: Garamond

text: Some distinctive characteristics in Garamond's letterforms are an 'e' with a small eye and the bowl of the 'a' which has a sharp turn at top left. Other general features are limited but clear stroke contrast and capital letters on the model of Roman square capitals. The 'M' is slightly splayed with outward-facing serifs at the top (sometimes only on the left) and the leg of the 'R' extends outwards from the letter. The x-height (height of lower-case letters) is low, especially at larger sizes, making the capitals large relative to the lower case, while the top serifs on the ascenders of letters like 'd' have a downward slope and ride above the cap height. The axis of letters like the ‘o’ is diagonal and the bottom right of the italic 'h' bends inwards. Garamond types have quite expansive ascenders and descenders; printers at the time did not use leading.


title: Garamond

text: Besides general characteristics, writers on type have generally praised the even quality of Garamond's type: John A. Lane describes his work as "elegant and executed with consummate skill...to a higher standard than commercial interest demanded"; H. D. L. Vervliet wrote that in his later "Gros-Canon" and "Parangonne" types (meaning sizes of around 40pt and 18pt respectively) he had achieved "a culmination of Renaissance design. The elegant line and subdued emphasis show the classic search for silent and transparent form".


title: Garamond

text: Modern Garamond revivals also often add a matching bold and 'lining' numbers at the height of capital letters, neither of which were used during the Renaissance; Arabic numerals in Garamond's time were engraved as what are now called text figures, styled with variable height like lower-case letters.


title: Garamond

text: Garamond worked as an engraver of punches, the masters used to stamp matrices, the moulds used to cast metal type. Garamond cut types in the 'roman', or upright style, in italic, and Greek. In the period of Garamond's early life roman type had been displacing the blackletter or Gothic type which was used in some (although not all) early French printing. Though his name was generally written as 'Garamont' in his lifetime, the spelling 'Garamond' became the most commonly used form after his death. H. D. L. Vervliet, the leading contemporary expert on French Renaissance printing, uses Garamont consistently.


title: Garamond

text: The roman designs of Garamond which are his most imitated were based on a font cut around 1495 for the Venetian printer Aldus Manutius by engraver Francesco Griffo. This was first used in the book "De Aetna", a short work by poet and cleric Pietro Bembo which was Manutius' first printing in the Latin alphabet. Historian Beatrice Warde has assessed "De Aetna" as something of a pilot project, a small book printed to a higher standard than Manutius' norm. Among other details, this font popularised the idea that in printing the cross-stroke of the 'e' should be level instead of slanting upwards to the right like handwriting, something imitated in almost all type designs since. French typefounders of the 16th century assiduously examined Manutius's work (and, it is thought, "De Aetna" in particular) as a source of inspiration: Garamond's roman, italic and greek typefaces were all influenced by types used by Manutius.


title: Garamond

text: An event which was to particularly define the course of the rest of Garamond's career came starting on 6 September 1530, when the printer Robert Estienne began to introduce a set of three roman types adapting the single roman type used in "De Aetna" to a range of sizes. These typefaces, with their "light colour and precise cut" were extremely influential and other Parisian printers immediately introduced copies. The largest size "Gros-canon" (42.5pt) particularly became a "phenomenon" in Paris: never before had a roman type been cut in so large a size. The designs copied Manutius's type even to the extent of copying the 'M' shown in "De Aetna" which, whether intentionally or due to a casting defect, had no serif pointing out of the letter at top right. This form was to appear in many fonts of the period, including Garamond's earlier ones, although by the end of his career he had switched to mostly using an M on the Roman capital model with a serif at top right.


title: Garamond

text: The period from 1520 to around 1560, encompassing Garamond's career, was an extremely busy period for typeface creation. Many fonts were cut, some such as Robert Estienne's for a single printer's exclusive use, others sold or traded between them (increasingly over time). The many active engravers included Garamond himself, Granjon, Guillaume Le Bé, particularly respected for his Hebrew fonts, Pierre Haultin, Antoine Augereau (who may have been Garamond's master), Estienne's stepfather Simon de Colines and others. This period saw the creation of a pool of high-quality punches and matrices, many of which would remain used for the next two centuries.


title: Garamond

text: Little is known about Garamond's life or work before 1540, although he wrote in a preface of having cut punches for type since childhood. He worked for a variety of employers on commission, creating punches and selling matrices to publishers and the government. Garamond's typefaces were popular abroad, and replaced Griffo's original roman type at the Aldine Press in Venice. He also worked as a publisher and bookseller. By 1549, a document from theologian Jean de Gagny specified that the goldsmith Charles Chiffin, who had cut an italic for his private printing press, should receive payment at the rate of "the best punchcutter in this city after master Claude Garamont", clearly showing that he was considered the pre-eminent punchcutter in Paris at this time.


title: Garamond

text: Vervliet concludes that Garamond created thirty-four typefaces for which an attribution can be confidently made (17 roman, 7 italic, 8 Greek, 2 Hebrew) and another three for which the attribution is problematic (one each of roman, Greek and Hebrew). If Garamond distributed specimens of his typefaces, as later punchcutters and typefounders did, none is known to survive, although one unsigned specimen in the Plantin-Moretus Museum collection, presenting a synopsis of his late "Parangon" type, may have been made around the time of his death or soon after.


title: Garamond

text: While some records such as Christophe Plantin's exist of what exact types were cut by Garamond himself, many details of his career remain uncertain: early estimates placed Garamond's date of birth around 1480, but modern opinion proposes much later estimates. A document called the Le Bé Memorandum (based on the memories of Guillaume Le Bé, but collated by one of his sons around 1643) suggests that Garamond finished his apprenticeship around 1510. This is considered unlikely by modern historians since his mother was still alive when he died in 1561 and little is known of him before around 1540.


title: Garamond

text: One particular question about Garamond's early career is whether he cut the typefaces used by Estienne from 1530. Because of Garamond's known connection with Estienne in his later career, it has been assumed that he cut them, but this was not mentioned in contemporary sources: Vervliet suggests that these 'Estienne typefaces' were not cut by Garamond and that his career began somewhat later. Vervliet suggests that the creator of this set of typefaces, sometimes called the 'Estienne Master', may have been a 'Master Constantin', recorded in the Le Bé Memorandum as a master type engraver of the period before Garamond but about whom nothing is otherwise known and to whom no obvious other body of work can be ascribed. If so, his disappearance from history (perhaps due to an early death, since all his presumed work appeared in just four years from 1530 to 1533) and the execution of Augereau on a charge of heresy in 1534 may have allowed Garamond's reputation to develop in the following decade.


title: Garamond

text: Regardless of these questions about his early career, Garamond's late career is well-recorded, with most of his later roman types (in Lane's view, his best work) preserved in complete sets of matrices at the Museum Plantin-Moretus, which has allowed example sets of characters to be cast, with further documentation and attributions from later inventories and specimen sheets. Of the Garamond types preserved, all include small capitals apart from the "gros-canon", and the "parangonne" uniquely includes terminal swash forms for a e m n r t (two forms) and z.


title: Garamond

text: Garamond cut more roman types than italics, which at the time were conceived separately to roman types rather than designed alongside them as complementary matches.


title: Garamond

text: Italics had again been introduced by Manutius in 1500; the first was cut by Griffo. This first italic used upright capitals, copying a popular style of calligraphy. The modern italic style of sloped capitals first appeared in 1527 and only slowly became popular. Accordingly, many of Garamond's italics were quite small and had upright capitals. Some of his italics did have sloped capitals, although Vervliet did not feel he integrated them effectively into the typeface design, "sloped capitals were (and stayed) a weakness in his designs."


title: Garamond

text: Garamond's italics were apparently not as used as widely as Granjon's and Haultin's, which spread widely across Europe. For example, on the 1592 Berner specimen, most of the romans were by Garamond but at least all but one, and probably all, of the italics are Granjon's. Similarly in the 1643 "Imprimerie royale" specimen, most of the italics are Granjon's. (Some books published by Garamond in 1545 use a very common italic of the period, not cut by him.)


title: Garamond

text: Garamond cut type for the Greek alphabet from the beginning of his recorded career: on 2 November 1540 he contracted to cut a series of Greek faces for the French government, to be used in printing by Robert Estienne. The resulting typeface, known as the "Grecs du roi", are very different from his Latin designs: again influenced by Greek typefaces used by Manutius (they were cut in three sizes, the same ones Manutius used), they were based on the elegant handwriting of Cretan scribe Angelo Vergecio, who used many ligatures and traditional contractions in his writing, and include a extraordinarily large number of alternate characters to faithfully replicate it. Arthur Tilley called the books printed from them "among the most finished specimens of typography that exist".


title: Garamond

text: The "Grecs du roi" punches and matrices remain the property of the French government. They were extremely influential and directly copied by many engravers for other printers, becoming the basis of Greek typeface design for the next two centuries.


title: Garamond

text: Although the "Grecs du roi" style was popular in Greek printing for the next two centuries, it is problematic for modern setting of body text, due to changing tastes in Greek printing: they are slanted, but modern Greek printing often uses upright type, and because Garamond's types were designed assuming that ligatures would be manually selected and inserted wherever needed; later metal types on the same model used fewer ligatures. Digital 'Garamond' releases such as Adobe's with Roman and Greek character sets often re-interpret the Greek, for instance with upright characters. A commercial digitisation from Anagrafi Fonts, "KS GrequeX", uses the OpenType format to include over 1100 abbreviations and ligatures, more than Garamond cut.


title: Garamond

text: According to Lane the most influential "Grecs du roi" copies were those of Granjon and Haultin, but others may have been cut by Jean Arnould and Nicolas de Villiers, amongst others. Another was made by Arthur Nicholls in London.


title: Garamond

text: Garamond died in 1561 and his punches and matrices were sold off by his widow. Purchasers included the Le Bé type foundry in Paris run by the family of Guillaume Le Bé and Christophe Plantin, who was in Paris at the time; the Frankfurt foundry often referred to by historians as Egenolff-Berner also came to acquire materials of Garamond's. Le Bé's son is known to have written to Plantin's successor Moretus offering to trade matrices so they could both have complementary type in a range of sizes. Konrad Berner showcased various types of Garamond's and other French engravers in a 1592 specimen, which named the types' engravers and would later be a source for historians.


title: Garamond

text: Plantin's collection of original Garamond punches and matrices survives at the Plantin-Moretus Museum in Antwerp, together with many other typefaces collected by Plantin from other typefounders of the period. The collection has been used extensively for research, for example by historians Harry Carter and Vervliet. Plantin also commissioned punchcutter Robert Granjon to create alternate characters for three Garamond fonts with shortened ascenders and descenders to allow tighter linespacing.


title: Garamond

text: Many modern revival fonts based on French renaissance printing are influenced by the work of Robert Granjon (c. 1513-90), particularly in italic. An engraver with a long and wide-ranging career, Granjon's work seems to have ranged much more widely than Garamond's focus on roman and Greek type, cutting type in italic, civilité (a cursive blackletter), and for the Vatican type in exotic alphabets including Arabic, Armenian and Hebrew. His career also took in stops in the Netherlands, Switzerland, Germany and finally for the last twelve years of his life Rome, where he ended his career in the service of the Vatican.


title: Garamond

text: Vervliet comments that Granjon "laid the foundation for our image of the way an Italic should look." Although he was not quite the first designer to use the idea of italics having capitals sloped to complement the roman, he "solved successfully the problem of a balanced inclination of the capitals, a feature much ahead of the designs with a more irregular slope of his Viennese and Mainz predecessors...and even compared to...Garamont. A proper optical harmony of the angle of slope is characteristic for all Granjon’s Italics; it allowed the compositor to use whole lines of capitals without causing too much giddiness." Granjon also cut many swash capitals, which Vervliet describes as "deliciously daring" and have often been copied, for instance in Robert Slimbach's revivals for Adobe (discussed below).


title: Garamond

text: Besides Garamond, Granjon and the "Estienne master", other engravers were active in the French renaissance style.


title: Garamond

text: Pierre Haultin particularly created many types which were very popular and distributed very widely around Europe: as a Protestant, he spent much of his career outside Paris working in Geneva, Lyons and La Rochelle and his nephew Jérôme established a career importing and casting his types in London, where his types were extremely common. In Carter's view Haultin "has been greatly underrated". Another engraver whose types were very popular in London was François Guyot, who moved from Paris to Antwerp and then London.


title: Garamond

text: In 1621, sixty years after Garamond's death, the French printer Jean Jannon released a specimen of typefaces in the Garamond/Granjon style. Jannon wrote in his specimen that:


title: Garamond

text: Seeing that for some time many persons have had to do with the art [of printing] who have greatly lowered it ... the desire came upon me to try if I might imitate, after some fashion, some one among those who honourably busied themselves with the art, [men whose deaths] I hear regretted every day [Jannon mentions some eminent printers of the previous century] ... and inasmuch as I could not accomplish this design for lack of types which I needed ... [some typefounders] would not, and others could not furnish me with what I lacked [so] I resolved, about six years ago, to turn my hand in good earnest to the making of punches, matrices and moulds for all sorts of characters, for the accommodation both of the public and of myself.


title: Garamond

text: Jannon was a Protestant in mostly Catholic France. After apparently working with the Estienne family in Paris he set up an independent career as printer in Sedan in what is now north-eastern France, becoming printer for the Protestant Academy. By his report he took up punchcutting seriously in his thirties, although according to Williamson he would have cut decorative material and engravings at least before this. Sedan the time enjoyed an unstable independence as a principality at a time when the French government had conceded through the Edict of Nantes to allowing a complicated system of restricted liberties for Protestants.


title: Garamond

text: The French Royal Printing Office (Imprimerie Royale) appears to have bought matrices from him in 1641 in three large sizes, roman and italic at roughly 18, 24 and 36 point sizes. (The contract is actually made for one 'Nicholas Jannon', which historians have concluded to be a mistake.) Despite the purchase, it is not clear that the office ever much used Jannon's type: historian James Mosley has reported being unable to find books printed by the Imprimerie that use more than two sizes of italic. His type would later be misattributed to Garamond. Despite this, it is known that authorities in 1644 raided an office in Caen where he had been commissioned to do printing. Warde initially assumed that this was the source of the Jannon materials in the Imprimerie Nationale before the government's purchase order came to light. Jannon's types and their descendants are recognizable by the scooped-out triangular serifs on the top left of such characters as 'm', 'n' and 'r', which curve to a steeper slant in Jannon's design compared to Garamond's. The italics are also very different from Garamond's own or Granjon's, being much more ornate and with considerable variation in angle of the capitals. Opinions of Jannon's engraving quality have varied; Warde found them "so technically brilliant as to be decadent" and "of slight value as a book face" (the surviving Jannon sizes were intended as display faces, cut at 18pt or larger) and Vervliet described them as "famous not so much for the quality of the design but as for the long-term confusion it created", although many reproductions of his work were successful in printing in the twentieth century. Jannon cut far more types than those surviving in the Imprimerie collection: before the misattribution to Garamond, he was particularly respected for his engraving of an extremely small size of type, known for his workplace as "sédanoise", which was popular.


title: Garamond

text: By the nineteenth century, Jannon's matrices had come to be known as the "Caractères de l'Université" (Characters of the University). It has sometimes been claimed that this term was an official name designated for the Jannon type by Cardinal Richelieu, while Warde in 1926 more plausibly suggested it might be a garbled recollection of Jannon's work with the Sedan Academy, which operated much like a university despite not using the name. Carter in the 1970s followed this conclusion. Mosley, however, concludes that no report of the term (or much use of Jannon's matrices at all) exists before the nineteenth century, and it may originate from a generic term of the eighteenth century simply meaning older or more conservative typeface designs, perhaps those preferred in academic publishing.


title: Garamond

text: The old-style typefaces of Garamond and his contemporaries continued to be regularly used and kept in the stock of European typefounders until the end of the eighteenth century and appear in the major French type foundry specimen books of the eighteenth century, of Delacolonge, Lamesle, and Gando. In Delacolonge's book, many fonts were shown "mutilated" or as "bastard" fonts: with replacement characters, specifically cut-down descenders to allow tighter linespacing. According to James Mosley French renaissance romans remained popular for slightly longer than italics, due to a taste for new italics, wider and with flat incoming serifs, introduced by the "Romain du roi" type and popularised by Simon-Pierre Fournier (see below): "it is common enough, in the second half of the eighteenth century, to find books set in a Garamond roman or a near copy mated with one of Fournier's italics".