title: Bob Monkhouse

text: The entire Monkhouse film and television archive is now held by Kaleidoscope, including all the material previously held by the National Film and Television Archive (NFTVA). It was catalogued and restored to digital formats for a major event at British Academy of Film and Television Arts (BAFTA) on 24 October 2009. Chris Perry, of Kaleidoscope and Kaleidoscope Publishing, said: "We are painstakingly transferring the important contents of the video tapes and restoring radio shows. There are many incredible finds, and the event [is] an exciting time for all concerned."


title: Bob Monkhouse

text: In his final years, Monkhouse hosted a show on BBC Radio 2 called "The Monkhouse Archive" in which he provided humorous links to clips of comedy acts spanning the previous 50 years.


title: Bob Monkhouse

text: In 1993 Monkhouse was appointed an Officer of the Order of the British Empire for services to entertainment.


title: Bob Monkhouse

text: In 1995 the British Comedy Awards gave him its Lifetime Achievement Award for Comedy, and eight years later, a few weeks before he died, the Television and Radio Industries Club awarded him a "Special Award for Outstanding Contribution to Broadcasting". He first appeared on "This Is Your Life" in 1982 and received a second appearance on the show on 23 April 2003, just months before his death.


title: Bob Monkhouse

text: In a poll of fellow comedians and comedy insiders to find the Comedians' Comedian in 2005, Monkhouse was voted among the best 50 comedy acts.


title: Bob Monkhouse

text: In a piece written several years after Monkhouse's death, critic and satirist Michael Deacon suggested that although Monkhouse had feared that his legacy as a comedian would be limited, as many people knew him only from his decades of work as a game-show host, his style of writing and performing could be seen as influencing many contemporary British comedians, such as Jimmy Carr (whose book on comedy "The Naked Jape" quoted several Monkhouse jokes), Michael McIntyre, Peter Kay, John Bishop, Lee Mack and Tim Vine.


title: Bob Monkhouse

text: Monkhouse was married twice, firstly to Elizabeth Thompson on 5 November 1949. The couple separated in 1967 and divorced in 1972. His second marriage, to Jacqueline Harding, lasted until his death. He had three children from his first marriage, but only his adopted daughter, Abigail, survived him.


title: Bob Monkhouse

text: His eldest son, Gary Alan, who had cerebral palsy, lived at Naish farm house, a residential home for the disabled in Christchurch Road, New Milton, Hampshire. He went to Saint Michael's School in Pinner and died in Braintree, Essex, in 1992, aged 40. Monkhouse was an avid campaigner for the disabled. His other son, Simon, a stand-up poet, from whom he had been estranged for 13 years, died aged 46 from a heroin overdose in a hotel in northern Thailand in April 2001.


title: Bob Monkhouse

text: Monkhouse lived in a house called "Claridges" in Eggington, near Leighton Buzzard, and had a flat in London and a holiday home in Barbados.


title: Bob Monkhouse

text: In his autobiography, he admitted to hundreds of sexual liaisons and affairs, but claimed that he only undertook this course of action because his first wife was unfaithful. His lovers before his second marriage included the actress Diana Dors, about whose parties he later commented after her death: "The awkward part about an orgy is that afterwards you're not too sure who to thank."


title: Bob Monkhouse

text: Throughout his career Monkhouse had jotted down jokes, odd facts, one-liners, sketches and ideas in a series of leather-bound books, which he took with him to every television, radio, stage and nightclub appearance he made. In July 1995 two were stolen, and Monkhouse offered a £15,000 reward. They were returned after 18 months, but the thief, although arrested, was never charged. On Monkhouse's death, the books were bequeathed to Colin Edmonds.


title: Bob Monkhouse

text: Monkhouse was a vocal supporter of the Conservative Party for some years. He later told his friend Colin Edmonds that this may have been a mistake, but that he wanted to be associated with a winner and he knew Margaret Thatcher could not lose the 1987 general election.


title: Bob Monkhouse

text: Monkhouse was diagnosed with prostate cancer in September 2001, and he died from this illness at his home on 29 December 2003. His widow, Jacqueline, suffered a heart attack and died in Barbados on 28 March 2008.


title: Bob Monkhouse

text: On 12 June 2007, Monkhouse posthumously appeared on British TV in an advertisement promoting awareness of prostate cancer for Male Cancer Awareness Week. Using computer animation techniques and a sound-alike actor, Monkhouse was seen in a graveyard next to his own grave (though in reality he was cremated) talking about the disease seriously, interspersed with humorous asides to another camera ("What killed me kills one man per hour in Britain. That's even more than my wife's cooking."). He ended by saying, "As a comedian, I've died many deaths. Prostate cancer, I don't recommend. I'd have paid good money to stay out of here. What's it worth to you?" before walking away from his grave and disappearing.


title: Bob Monkhouse

text: The advertisement was made with the support of Monkhouse's estate and supported by poster campaigns, including award-winning panels displayed in London Underground trains. Money raised went to the Prostate Cancer Research Foundation.


title: Membrane potential

text: Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. That is, there is a difference in the energy required for electric charges to move from the internal to exterior cellular environments and vice versa, as long as there is no acquisition of kinetic energy or the production of radiation. The concentration gradients of the charges directly determine this energy requirement. For the exterior of the cell, typical values of membrane potential, normally given in units of milli volts and denoted as mV, range from –80 mV to –40 mV.


title: Membrane potential

text: All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Transmembrane proteins, also known as ion transporter or ion pump proteins, actively push ions across the membrane and establish concentration gradients across the membrane, and ion channels allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane, and therefore create a voltage between the two sides of the membrane.


title: Membrane potential

text: Almost all plasma membranes have an electrical potential across them, with the inside usually negative with respect to the outside. The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of "molecular devices" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly sensed by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.


title: Membrane potential

text: In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the resting potential. For neurons, resting potential is defined as ranging from –80 to –70 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV). In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity. Action potentials are generated by the activation of certain voltage-gated ion channels.


title: Membrane potential

text: In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.


title: Membrane potential

text: The membrane potential in a cell derives ultimately from two factors: electrical force and diffusion. Electrical force arises from the mutual attraction between particles with opposite electrical charges (positive and negative) and the mutual repulsion between particles with the same type of charge (both positive or both negative). Diffusion arises from the statistical tendency of particles to redistribute from regions where they are highly concentrated to regions where the concentration is low.


title: Membrane potential

text: Voltage, which is synonymous with "difference in electrical potential", is the ability to drive an electric current across a resistance. Indeed, the simplest definition of a voltage is given by Ohm's law: V=IR, where V is voltage, I is current and R is resistance. If a voltage source such as a battery is placed in an electrical circuit, the higher the voltage of the source the greater the amount of current that it will drive across the available resistance. The functional significance of voltage lies only in potential "differences" between two points in a circuit. The idea of a voltage at a single point is meaningless. It is conventional in electronics to assign a voltage of zero to some arbitrarily chosen element of the circuit, and then assign voltages for other elements measured relative to that zero point. There is no significance in which element is chosen as the zero point—the function of a circuit depends only on the differences not on voltages "per se". However, in most cases and by convention, the zero level is most often assigned to the portion of a circuit that is in contact with ground.


title: Membrane potential

text: The same principle applies to voltage in cell biology. In electrically active tissue, the potential difference between any two points can be measured by inserting an electrode at each point, for example one inside and one outside the cell, and connecting both electrodes to the leads of what is in essence a specialized voltmeter. By convention, the zero potential value is assigned to the outside of the cell and the sign of the potential difference between the outside and the inside is determined by the potential of the inside relative to the outside zero.


title: Membrane potential

text: In mathematical terms, the definition of voltage begins with the concept of an electric field , a vector field assigning a magnitude and direction to each point in space. In many situations, the electric field is a conservative field, which means that it can be expressed as the gradient of a scalar function , that is, . This scalar field is referred to as the voltage distribution. Note that the definition allows for an arbitrary constant of integration—this is why absolute values of voltage are not meaningful. In general, electric fields can be treated as conservative only if magnetic fields do not significantly influence them, but this condition usually applies well to biological tissue.


title: Membrane potential

text: Because the electric field is the gradient of the voltage distribution, rapid changes in voltage within a small region imply a strong electric field; on the converse, if the voltage remains approximately the same over a large region, the electric fields in that region must be weak. A strong electric field, equivalent to a strong voltage gradient, implies that a strong force is exerted on any charged particles that lie within the region.


title: Membrane potential

text: Electrical signals within biological organisms are, in general, driven by ions. The most important cations for the action potential are sodium (Na) and potassium (K). Both of these are "monovalent" cations that carry a single positive charge. Action potentials can also involve calcium (Ca), which is a "divalent" cation that carries a double positive charge. The chloride anion (Cl) plays a major role in the action potentials of some algae, but plays a negligible role in the action potentials of most animals.


title: Membrane potential

text: Ions cross the cell membrane under two influences: diffusion and electric fields. A simple example wherein two solutions—A and B—are separated by a porous barrier illustrates that diffusion will ensure that they will eventually mix into equal solutions. This mixing occurs because of the difference in their concentrations. The region with high concentration will diffuse out toward the region with low concentration. To extend the example, let solution A have 30 sodium ions and 30 chloride ions. Also, let solution B have only 20 sodium ions and 20 chloride ions. Assuming the barrier allows both types of ions to travel through it, then a steady state will be reached whereby both solutions have 25 sodium ions and 25 chloride ions. If, however, the porous barrier is selective to which ions are let through, then diffusion alone will not determine the resulting solution. Returning to the previous example, let's now construct a barrier that is permeable only to sodium ions. Now, only sodium is allowed to diffuse cross the barrier from its higher concentration in solution A to the lower concentration in solution B. This will result in a greater accumulation of sodium ions than chloride ions in solution B and a lesser number of sodium ions than chloride ions in solution A.


title: Membrane potential

text: This means that there is a net positive charge in solution B from the higher concentration of positively charged sodium ions than negatively charged chloride ions. Likewise, there is a net negative charge in solution A from the greater concentration of negative chloride ions than positive sodium ions. Since opposite charges attract and like charges repel, the ions are now also influenced by electrical fields as well as forces of diffusion. Therefore, positive sodium ions will be less likely to travel to the now-more-positive B solution and remain in the now-more-negative A solution. The point at which the forces of the electric fields completely counteract the force due to diffusion is called the equilibrium potential. At this point, the net flow of the specific ion (in this case sodium) is zero.


title: Membrane potential

text: Every cell is enclosed in a plasma membrane, which has the structure of a lipid bilayer with many types of large molecules embedded in it. Because it is made of lipid molecules, the plasma membrane intrinsically has a high electrical resistivity, in other words a low intrinsic permeability to ions. However, some of the molecules embedded in the membrane are capable either of actively transporting ions from one side of the membrane to the other or of providing channels through which they can move.


title: Membrane potential

text: In electrical terminology, the plasma membrane functions as a combined resistor and capacitor. Resistance arises from the fact that the membrane impedes the movement of charges across it. Capacitance arises from the fact that the lipid bilayer is so thin that an accumulation of charged particles on one side gives rise to an electrical force that pulls oppositely charged particles toward the other side. The capacitance of the membrane is relatively unaffected by the molecules that are embedded in it, so it has a more or less invariant value estimated at 2 μF/cm (the total capacitance of a patch of membrane is proportional to its area). The conductance of a pure lipid bilayer is so low, on the other hand, that in biological situations it is always dominated by the conductance of alternative pathways provided by embedded molecules. Thus, the capacitance of the membrane is more or less fixed, but the resistance is highly variable.


title: Membrane potential

text: The thickness of a plasma membrane is estimated to be about 7-8 nanometers. Because the membrane is so thin, it does not take a very large transmembrane voltage to create a strong electric field within it. Typical membrane potentials in animal cells are on the order of 100 millivolts (that is, one tenth of a volt), but calculations show that this generates an electric field close to the maximum that the membrane can sustain—it has been calculated that a voltage difference much larger than 200 millivolts could cause dielectric breakdown, that is, arcing across the membrane.


title: Membrane potential

text: The resistance of a pure lipid bilayer to the passage of ions across it is very high, but structures embedded in the membrane can greatly enhance ion movement, either actively or passively, via mechanisms called facilitated transport and facilitated diffusion. The two types of structure that play the largest roles are ion channels and ion pumps, both usually formed from assemblages of protein molecules. Ion channels provide passageways through which ions can move. In most cases, an ion channel is permeable only to specific types of ions (for example, sodium and potassium but not chloride or calcium), and sometimes the permeability varies depending on the direction of ion movement. Ion pumps, also known as ion transporters or carrier proteins, actively transport specific types of ions from one side of the membrane to the other, sometimes using energy derived from metabolic processes to do so.


title: Membrane potential

text: Ion pumps are integral membrane proteins that carry out active transport, i.e., use cellular energy (ATP) to "pump" the ions against their concentration gradient. Such ion pumps take in ions from one side of the membrane (decreasing its concentration there) and release them on the other side (increasing its concentration there).


title: Membrane potential

text: The ion pump most relevant to the action potential is the sodium–potassium pump, which transports three sodium ions out of the cell and two potassium ions in. As a consequence, the concentration of potassium ions K inside the neuron is roughly 20-fold larger than the outside concentration, whereas the sodium concentration outside is roughly ninefold larger than inside. In a similar manner, other ions have different concentrations inside and outside the neuron, such as calcium, chloride and magnesium.


title: Membrane potential

text: If the numbers of each type of ion were equal, the sodium–potassium pump would be electrically neutral, but, because of the three-for-two exchange, it gives a net movement of one positive charge from intracellular to extracellular for each cycle, thereby contributing to a positive voltage difference. The pump has three effects: (1) it makes the sodium concentration high in the extracellular space and low in the intracellular space; (2) it makes the potassium concentration high in the intracellular space and low in the extracellular space; (3) it gives the intracellular space a negative voltage with respect to the extracellular space.


title: Membrane potential

text: The sodium-potassium pump is relatively slow in operation. If a cell were initialized with equal concentrations of sodium and potassium everywhere, it would take hours for the pump to establish equilibrium. The pump operates constantly, but becomes progressively less efficient as the concentrations of sodium and potassium available for pumping are reduced.


title: Membrane potential

text: Ion pumps influence the action potential only by establishing the relative ratio of intracellular and extracellular ion concentrations. The action potential involves mainly the opening and closing of ion channels not ion pumps. If the ion pumps are turned off by removing their energy source, or by adding an inhibitor such as ouabain, the axon can still fire hundreds of thousands of action potentials before their amplitudes begin to decay significantly. In particular, ion pumps play no significant role in the repolarization of the membrane after an action potential.


title: Membrane potential

text: Another functionally important ion pump is the sodium-calcium exchanger. This pump operates in a conceptually similar way to the sodium-potassium pump, except that in each cycle it exchanges three Na from the extracellular space for one Ca from the intracellular space. Because the net flow of charge is inward, this pump runs "downhill", in effect, and therefore does not require any energy source except the membrane voltage. Its most important effect is to pump calcium outward—it also allows an inward flow of sodium, thereby counteracting the sodium-potassium pump, but, because overall sodium and potassium concentrations are much higher than calcium concentrations, this effect is relatively unimportant. The net result of the sodium-calcium exchanger is that in the resting state, intracellular calcium concentrations become very low.


title: Membrane potential

text: Ion channels are integral membrane proteins with a pore through which ions can travel between extracellular space and cell interior. Most channels are specific (selective) for one ion; for example, most potassium channels are characterized by 1000:1 selectivity ratio for potassium over sodium, though potassium and sodium ions have the same charge and differ only slightly in their radius. The channel pore is typically so small that ions must pass through it in single-file order. Channel pores can be either open or closed for ion passage, although a number of channels demonstrate various sub-conductance levels. When a channel is open, ions permeate through the channel pore down the transmembrane concentration gradient for that particular ion. Rate of ionic flow through the channel, i.e. single-channel current amplitude, is determined by the maximum channel conductance and electrochemical driving force for that ion, which is the difference between the instantaneous value of the membrane potential and the value of the reversal potential.


title: Membrane potential

text: A channel may have several different states (corresponding to different conformations of the protein), but each such state is either open or closed. In general, closed states correspond either to a contraction of the pore—making it impassable to the ion—or to a separate part of the protein, stoppering the pore. For example, the voltage-dependent sodium channel undergoes "inactivation", in which a portion of the protein swings into the pore, sealing it. This inactivation shuts off the sodium current and plays a critical role in the action potential.


title: Membrane potential

text: Ion channels can be classified by how they respond to their environment. For example, the ion channels involved in the action potential are "voltage-sensitive channels"; they open and close in response to the voltage across the membrane. "Ligand-gated channels" form another important class; these ion channels open and close in response to the binding of a ligand molecule, such as a neurotransmitter. Other ion channels open and close with mechanical forces. Still other ion channels—such as those of sensory neurons—open and close in response to other stimuli, such as light, temperature or pressure.


title: Membrane potential

text: Leakage channels are the simplest type of ion channel, in that their permeability is more or less constant. The types of leakage channels that have the greatest significance in neurons are potassium and chloride channels. Even these are not perfectly constant in their properties: First, most of them are voltage-dependent in the sense that they conduct better in one direction than the other (in other words, they are rectifiers); second, some of them are capable of being shut off by chemical ligands even though they do not require ligands in order to operate.


title: Membrane potential

text: Ligand-gated ion channels are channels whose permeability is greatly increased when some type of chemical ligand binds to the protein structure. Animal cells contain hundreds, if not thousands, of types of these. A large subset function as neurotransmitter receptors—they occur at postsynaptic sites, and the chemical ligand that gates them is released by the presynaptic axon terminal. One example of this type is the AMPA receptor, a receptor for the neurotransmitter glutamate that when activated allows passage of sodium and potassium ions. Another example is the GABA receptor, a receptor for the neurotransmitter GABA that when activated allows passage of chloride ions.


title: Membrane potential

text: Neurotransmitter receptors are activated by ligands that appear in the extracellular area, but there are other types of ligand-gated channels that are controlled by interactions on the intracellular side.


title: Membrane potential

text: Voltage-gated ion channels, also known as "voltage dependent ion channels", are channels whose permeability is influenced by the membrane potential. They form another very large group, with each member having a particular ion selectivity and a particular voltage dependence. Many are also time-dependent—in other words, they do not respond immediately to a voltage change but only after a delay.


title: Membrane potential

text: One of the most important members of this group is a type of voltage-gated sodium channel that underlies action potentials—these are sometimes called "Hodgkin-Huxley sodium channels" because they were initially characterized by Alan Lloyd Hodgkin and Andrew Huxley in their Nobel Prize-winning studies of the physiology of the action potential. The channel is closed at the resting voltage level, but opens abruptly when the voltage exceeds a certain threshold, allowing a large influx of sodium ions that produces a very rapid change in the membrane potential. Recovery from an action potential is partly dependent on a type of voltage-gated potassium channel that is closed at the resting voltage level but opens as a consequence of the large voltage change produced during the action potential.


title: Membrane potential

text: The reversal potential (or "equilibrium potential") of an ion is the value of transmembrane voltage at which diffusive and electrical forces counterbalance, so that there is no net ion flow across the membrane. This means that the transmembrane voltage exactly opposes the force of diffusion of the ion, such that the net current of the ion across the membrane is zero and unchanging. The reversal potential is important because it gives the voltage that acts on channels permeable to that ion—in other words, it gives the voltage that the ion concentration gradient generates when it acts as a battery.


title: Membrane potential

text: The equilibrium potential of a particular ion is usually designated by the notation "E".The equilibrium potential for any ion can be calculated using the Nernst equation. For example, reversal potential for potassium ions will be as follows:


title: Membrane potential

text: Even if two different ions have the same charge (i.e., K and Na), they can still have very different equilibrium potentials, provided their outside and/or inside concentrations differ. Take, for example, the equilibrium potentials of potassium and sodium in neurons. The potassium equilibrium potential "E" is −84 mV with 5 mM potassium outside and 140 mM inside. On the other hand, the sodium equilibrium potential, "E", is approximately +66 mV with approximately 12 mM sodium inside and 140 mM outside.


title: Membrane potential

text: A neuron's resting membrane potential actually changes during the development of an organism. In order for a neuron to eventually adopt its full adult function, its potential must be tightly regulated during development. As an organism progresses through development the resting membrane potential becomes more negative. Glial cells are also differentiating and proliferating as development progresses in the brain. The addition of these glial cells increases the organism's ability to regulate extracellular potassium. The drop in extracellular potassium can lead to a decrease in membrane potential of 35 mV.


title: Membrane potential

text: Cell excitability is the change in membrane potential that is necessary for cellular responses in various tissues. Cell excitability is a property that is induced during early embriogenesis. Excitability of a cell has also been defined as the ease with which a response may be triggered. The resting and threshold potentials forms the basis of cell excitability and these processes are fundamental for the generation of graded and action potentials.


title: Membrane potential

text: The most important regulators of cell excitability are the extracellular electrolyte concentrations (i.e. Na, K, Ca, Cl, Mg) and associated proteins. Important proteins that regulate cell excitability are voltage-gated ion channels, ion transporters (e.g. Na+/K+-ATPase, magnesium transporters, acid–base transporters), membrane receptors and hyperpolarization-activated cyclic-nucleotide-gated channels. For example, potassium channels and calcium-sensing receptors are important regulators of excitability in neurons, cardiac myocytes and many other excitable cells like astrocytes. Calcium ion is also the most important second messenger in excitable cell signaling. Activation of synaptic receptors initiates long-lasting changes in neuronal excitability. Thyroid, adrenal and other hormones also regulate cell excitability, for example, progesterone and estrogen modulate myometrial smooth muscle cell excitability.


title: Membrane potential

text: Many cell types are considered to have an excitable membrane. Excitable cells are neurons, myocytes (cardiac, skeletal, smooth), vascular endothelial cells, pericytes, juxtaglomerular cells, interstitial cells of Cajal, many types of epithelial cells (e.g. beta cells, alpha cells, delta cells, enteroendocrine cells, pulmonary neuroendocrine cells, pinealocytes), glial cells (e.g. astrocytes), mechanoreceptor cells (e.g. hair cells and Merkel cells), chemoreceptor cells (e.g. glomus cells, taste receptors), some plant cells and possibly immune cells. Astrocytes display a form of non-electrical excitability based on intracellular calcium variations related to the expression of several receptors through which they can detect the synaptic signal. In neurons, there are different membrane properties in some portions of the cell, for example, dendritic excitability endows neurons with the capacity for coincidence detection of spatially separated inputs.


title: Membrane potential

text: Electrophysiologists model the effects of ionic concentration differences, ion channels, and membrane capacitance in terms of an equivalent circuit, which is intended to represent the electrical properties of a small patch of membrane. The equivalent circuit consists of a capacitor in parallel with four pathways each consisting of a battery in series with a variable conductance. The capacitance is determined by the properties of the lipid bilayer, and is taken to be fixed. Each of the four parallel pathways comes from one of the principal ions, sodium, potassium, chloride, and calcium. The voltage of each ionic pathway is determined by the concentrations of the ion on each side of the membrane; see the Reversal potential section above. The conductance of each ionic pathway at any point in time is determined by the states of all the ion channels that are potentially permeable to that ion, including leakage channels, ligand-gated channels, and voltage-gated ion channels.


title: Membrane potential

text: For fixed ion concentrations and fixed values of ion channel conductance, the equivalent circuit can be further reduced, using the Goldman equation as described below, to a circuit containing a capacitance in parallel with a battery and conductance. In electrical terms, this is a type of RC circuit (resistance-capacitance circuit), and its electrical properties are very simple. Starting from any initial state, the current flowing across either the conductance or the capacitance decays with an exponential time course, with a time constant of , where is the capacitance of the membrane patch, and is the net resistance. For realistic situations, the time constant usually lies in the 1—100 millisecond range. In most cases, changes in the conductance of ion channels occur on a faster time scale, so an RC circuit is not a good approximation; however, the differential equation used to model a membrane patch is commonly a modified version of the RC circuit equation.


title: Membrane potential

text: When the membrane potential of a cell goes for a long period of time without changing significantly, it is referred to as a resting potential or resting voltage. This term is used for the membrane potential of non-excitable cells, but also for the membrane potential of excitable cells in the absence of excitation. In excitable cells, the other possible states are graded membrane potentials (of variable amplitude), and action potentials, which are large, all-or-nothing rises in membrane potential that usually follow a fixed time course. Excitable cells include neurons, muscle cells, and some secretory cells in glands. Even in other types of cells, however, the membrane voltage can undergo changes in response to environmental or intracellular stimuli. For example, depolarization of the plasma membrane appears to be an important step in programmed cell death.


title: Membrane potential

text: The interactions that generate the resting potential are modeled by the Goldman equation. This is similar in form to the Nernst equation shown above, in that it is based on the charges of the ions in question, as well as the difference between their inside and outside concentrations. However, it also takes into consideration the relative permeability of the plasma membrane to each ion in question.


title: Membrane potential

text: The three ions that appear in this equation are potassium (K), sodium (Na), and chloride (Cl). Calcium is omitted, but can be added to deal with situations in which it plays a significant role. Being an anion, the chloride terms are treated differently from the cation terms; the intracellular concentration is in the numerator, and the extracellular concentration in the denominator, which is reversed from the cation terms. "P" stands for the relative permeability of the ion type i.


title: Membrane potential

text: In essence, the Goldman formula expresses the membrane potential as a weighted average of the reversal potentials for the individual ion types, weighted by permeability. (Although the membrane potential changes about 100 mV during an action potential, the concentrations of ions inside and outside the cell do not change significantly. They remain close to their respective concentrations when then membrane is at resting potential.) In most animal cells, the permeability to potassium is much higher in the resting state than the permeability to sodium. As a consequence, the resting potential is usually close to the potassium reversal potential. The permeability to chloride can be high enough to be significant, but, unlike the other ions, chloride is not actively pumped, and therefore equilibrates at a reversal potential very close to the resting potential determined by the other ions.


title: Membrane potential

text: Values of resting membrane potential in most animal cells usually vary between the potassium reversal potential (usually around -80 mV) and around -40 mV. The resting potential in excitable cells (capable of producing action potentials) is usually near -60 mV—more depolarized voltages would lead to spontaneous generation of action potentials. Immature or undifferentiated cells show highly variable values of resting voltage, usually significantly more positive than in differentiated cells. In such cells, the resting potential value correlates with the degree of differentiation: undifferentiated cells in some cases may not show any transmembrane voltage difference at all.


title: Membrane potential

text: Maintenance of the resting potential can be metabolically costly for a cell because of its requirement for active pumping of ions to counteract losses due to leakage channels. The cost is highest when the cell function requires an especially depolarized value of membrane voltage. For example, the resting potential in daylight-adapted blowfly ("Calliphora vicina") photoreceptors can be as high as -30 mV. This elevated membrane potential allows the cells to respond very rapidly to visual inputs; the cost is that maintenance of the resting potential may consume more than 20% of overall cellular ATP.


title: Membrane potential

text: On the other hand, the high resting potential in undifferentiated cells does not necessarily incur a high metabolic cost. This apparent paradox is resolved by examination of the origin of that resting potential. Little-differentiated cells are characterized by extremely high input resistance, which implies that few leakage channels are present at this stage of cell life. As an apparent result, potassium permeability becomes similar to that for sodium ions, which places resting potential in-between the reversal potentials for sodium and potassium as discussed above. The reduced leakage currents also mean there is little need for active pumping in order to compensate, therefore low metabolic cost.


title: Membrane potential

text: As explained above, the potential at any point in a cell's membrane is determined by the ion concentration differences between the intracellular and extracellular areas, and by the permeability of the membrane to each type of ion. The ion concentrations do not normally change very quickly (with the exception of Ca, where the baseline intracellular concentration is so low that even a small influx may increase it by orders of magnitude), but the permeabilities of the ions can change in a fraction of a millisecond, as a result of activation of ligand-gated ion channels. The change in membrane potential can be either large or small, depending on how many ion channels are activated and what type they are, and can be either long or short, depending on the lengths of time that the channels remain open. Changes of this type are referred to as graded potentials, in contrast to action potentials, which have a fixed amplitude and time course.


title: Membrane potential

text: As can be derived from the Goldman equation shown above, the effect of increasing the permeability of a membrane to a particular type of ion shifts the membrane potential toward the reversal potential for that ion. Thus, opening Na channels shifts the membrane potential toward the Na reversal potential, which is usually around +100 mV. Likewise, opening K channels shifts the membrane potential toward about –90 mV, and opening Cl channels shifts it toward about –70 mV (resting potential of most membranes). Thus, Na channels shift the membrane potential in a positive direction, K channels shift it in a negative direction (except when the membrane is hyperpolarized to a value more negative than the K reversal potential), and Cl channels tend to shift it towards the resting potential.


title: Membrane potential

text: Graded membrane potentials are particularly important in neurons, where they are produced by synapses—a temporary change in membrane potential produced by activation of a synapse by a single graded or action potential is called a postsynaptic potential. Neurotransmitters that act to open Na channels typically cause the membrane potential to become more positive, while neurotransmitters that activate K channels typically cause it to become more negative; those that inhibit these channels tend to have the opposite effect.


title: Membrane potential

text: Whether a postsynaptic potential is considered excitatory or inhibitory depends on the reversal potential for the ions of that current, and the threshold for the cell to fire an action potential (around –50mV). A postsynaptic current with a reversal potential above threshold, such as a typical Na current, is considered excitatory. A current with a reversal potential below threshold, such as a typical K current, is considered inhibitory. A current with a reversal potential above the resting potential, but below threshold, will not by itself elicit action potentials, but will produce subthreshold membrane potential oscillations. Thus, neurotransmitters that act to open Na channels produce excitatory postsynaptic potentials, or EPSPs, whereas neurotransmitters that act to open K or Cl channels typically produce inhibitory postsynaptic potentials, or IPSPs. When multiple types of channels are open within the same time period, their postsynaptic potentials summate (are added together).


title: Membrane potential

text: From the viewpoint of biophysics, the "resting" membrane potential is merely the membrane potential that results from the membrane permeabilities that predominate when the cell is resting. The above equation of weighted averages always applies, but the following approach may be more easily visualized.


title: Membrane potential

text: At any given moment, there are two factors for an ion that determine how much influence that ion will have over the membrane potential of a cell:


title: Membrane potential

text: If the driving force is high, then the ion is being "pushed" across the membrane. If the permeability is high, it will be easier for the ion to diffuse across the membrane.


title: Membrane potential

text: So, in a resting membrane, while the driving force for potassium is low, its permeability is very high. Sodium has a huge driving force but almost no resting permeability. In this case, potassium carries about 20 times more current than sodium, and thus has 20 times more influence over "E" than does sodium.


title: Membrane potential

text: However, consider another case—the peak of the action potential. Here, permeability to Na is high and K permeability is relatively low. Thus, the membrane moves to near "E" and far from "E".


title: Membrane potential

text: The more ions are permeant the more complicated it becomes to predict the membrane potential. However, this can be done using the Goldman-Hodgkin-Katz equation or the weighted means equation. By plugging in the concentration gradients and the permeabilities of the ions at any instant in time, one can determine the membrane potential at that moment. What the GHK equations means is that, at any time, the value of the membrane potential will be a weighted average of the equilibrium potentials of all permeant ions. The "weighting" is the ions relative permeability across the membrane.


title: Membrane potential

text: While cells expend energy to transport ions and establish a transmembrane potential, they use this potential in turn to transport other ions and metabolites such as sugar. The transmembrane potential of the mitochondria drives the production of ATP, which is the common currency of biological energy.


title: Membrane potential

text: Cells may draw on the energy they store in the resting potential to drive action potentials or other forms of excitation. These changes in the membrane potential enable communication with other cells (as with action potentials) or initiate changes inside the cell, which happens in an egg when it is fertilized by a sperm.


title: Membrane potential

text: In neuronal cells, an action potential begins with a rush of sodium ions into the cell through sodium channels, resulting in depolarization, while recovery involves an outward rush of potassium through potassium channels. Both of these fluxes occur by passive diffusion.


title: Membrane potential

text: Changes in the dielectric properties of plasma membrane may act as hallmark of underlying conditions such as diabetes and dyslipidemia.


title: Seventeenth Amendment to the United States Constitution

text: The Seventeenth Amendment (Amendment XVII) to the United States Constitution established the direct election of United States senators in each state. The amendment supersedes , Clauses 1 and2 of the Constitution, under which senators were elected by state legislatures. It also alters the procedure for filling vacancies in the Senate, allowing for state legislatures to permit their governors to make temporary appointments until a special election can be held.


text: The amendment was proposed by the 62nd Congress in 1912 and became part of the Constitution on April 8, 1913, on ratification by three-quarters (36) of the state legislatures. Sitting senators were not affected until their existing terms expired. The transition began with two special elections in Georgia and Maryland, then in earnest with the November 1914 election; it was complete on March 4, 1919, when the senators chosen at the November 1918 election took office.


text: Originally, under , Clauses 1 and2 of the Constitution, each state legislature elected its state's senators for a six-year term. Each state, regardless of size, is entitled to two senators as part of the Connecticut Compromise between the small and large states. This contrasted with the House of Representatives, a body elected by popular vote, and was described as an uncontroversial decision; at the time, James Wilson was the sole advocate of popularly electing the Senate, but his proposal was defeated 10–1. There were many advantages to the original method of electing senators. Prior to the Constitution, a federal body was one where states effectively formed nothing more than permanent treaties, with citizens retaining their loyalty to their original state. However, under the new Constitution, the federal government was granted substantially more power than before. Having the state legislatures elect the senators reassured anti-federalists that there would be some protection against the federal government's swallowing up states and their powers, and providing a check on the power of the federal government.


text: Additionally, the longer terms and avoidance of popular election turned the Senate into a body that could counter the populism of the House. While the representatives operated in a two-year direct election cycle, making them frequently accountable to their constituents, the senators could afford to "take a more detached view of issues coming before Congress". State legislatures retained the theoretical right to "instruct" their senators to vote for or against proposals, thus giving the states both direct and indirect representation in the federal government. The Senate was part of a formal bicameralism, with the members of the Senate and House responsible to completely distinct constituencies; this helped defeat the problem of the federal government being subject to "special interests". Members of the Constitutional Convention considered the Senate to be parallel to the British House of Lords as an "upper house", containing the "better men" of society, but improved upon as they would be conscientiously chosen by the upper houses of state legislatures for fixed terms, and not merely inherited for life as in the British system, subject to a monarch's arbitrary expansion. It was hoped they would provide abler deliberation and greater stability than the House of Representatives due to the senators' status.


text: According to Judge Jay Bybee of the United States Court of Appeals for the Ninth Circuit, those in favor of popular elections for senators believed two primary problems were caused by the original provisions: legislative corruption and electoral deadlocks. There was a sense that senatorial elections were "bought and sold", changing hands for favors and sums of money rather than because of the competence of the candidate. Between 1857 and 1900, the Senate investigated three elections over corruption. In 1900, for example, William A. Clark had his election voided after the Senate concluded that he had bought votes in the Montana legislature. But conservative analysts Bybee and Todd Zywicki believe this concern was largely unfounded; there was a "dearth of hard information" on the subject. In more than a century of legislative elections of U.S. senators, only ten cases were contested for allegations of impropriety.


text: Electoral deadlocks were another issue. Because state legislatures were charged with deciding whom to appoint as senators, the system relied on their ability to agree. Some states could not, and thus delayed sending senators to Congress; in a few cases, the system broke down to the point where states completely lacked representation in the Senate. Deadlocks started to become an issue in the 1850s, with a deadlocked Indiana legislature allowing a Senate seat to sit vacant for two years. The tipping point came in 1865 with the election of John P. Stockton (D-NJ), which happened after the New Jersey legislature changed its rules regarding the definition of a quorum and was thus elected by plurality instead of by absolute majority.


text: In 1866, Congress acted to standardize a two-step process for Senate elections. In the first step, each chamber of the state legislature would meet separately to vote. The following day, the chambers would meet in "joint assembly" to assess the results, and if a majority in both chambers had voted for the same person, he would be elected. If not, the joint assembly would vote for a senator, with each member receiving a vote. If no person received a majority, the joint assembly was required to keep convening every day to take at least one vote until a senator was elected. Nevertheless, between 1891 and 1905, 46 elections were deadlocked across 20 states; in one extreme example, a Senate seat for Delaware went unfilled from 1899 until 1903. The business of holding elections also caused great disruption in the state legislatures, with a full third of the Oregon House of Representatives choosing not to swear the oath of office in 1897 due to a dispute over an open Senate seat. The result was that Oregon's legislature was unable to pass legislation that year.


text: Zywicki again argues that this was not a serious issue. Deadlocks were a problem, but they were the exception rather than the norm; many legislatures did not deadlock over elections at all. Most of those that did in the 19th century were the newly admitted western states, which suffered from "inexperienced legislatures and weak party discipline... as western legislatures gained experience, deadlocks became less frequent." While Utah suffered from deadlocks in 1897 and 1899, they became what Zywicki refers to as "a good teaching experience", and Utah never again failed to elect senators. Another concern was that when deadlocks occurred, state legislatures were unable to conduct their other normal business; James Christian Ure, writing in the "South Texas Law Review", notes that this did not in fact occur. In a deadlock situation, state legislatures would deal with the matter by holding "one vote at the beginning of the day—then the legislators would continue with their normal affairs".


text: Eventually, legislative elections held in a state's Senate election years were perceived to have become so dominated by the business of picking senators that the state's choice for senator distracted the electorate from all other pertinent issues. Senator John H. Mitchell noted that the Senate became the "vital issue" in all legislative campaigns, with the policy stances and qualifications of state legislative candidates ignored by voters who were more interested in the indirect Senate election. To remedy this, some state legislatures created "advisory elections" that served as de facto general elections, allowing legislative campaigns to focus on local issues.


text: Calls for a constitutional amendment regarding Senate elections started in the early 19th century, with Henry R. Storrs in 1826 proposing an amendment to provide for popular election. Similar amendments were introduced in 1829 and 1855, with the "most prominent" proponent being Andrew Johnson, who raised the issue in 1868 and considered the idea's merits "so palpable" that no additional explanation was necessary. As noted above, in the 1860s, there was a major congressional dispute over the issue, with the House and Senate voting to veto the appointment of John P. Stockton to the Senate due to his approval by a plurality of the New Jersey Legislature rather than a majority. In reaction, the Congress passed a bill in July 1866 that required state legislatures to elect senators by an absolute majority.


text: By the 1890s, support for the introduction of direct election for the Senate had substantially increased, and reformers worked on two fronts. On the first front, the Populist Party incorporated the direct election of senators into its Omaha Platform, adopted in 1892. In 1908, Oregon passed the first law basing the selection of U.S. senators on a popular vote. Oregon was soon followed by Nebraska. Proponents for popular election noted that ten states already had non-binding primaries for Senate candidates, in which the candidates would be voted on by the public, effectively serving as advisory referendums instructing state legislatures how to vote; reformers campaigned for more states to introduce a similar method.


text: William Randolph Hearst opened a nationwide popular readership for direct election of U.S. senators in a 1906 series of articles using flamboyant language attacking "The Treason of the Senate" in his "Cosmopolitan" magazine. David Graham Philips, one of the "yellow journalists" whom President Teddy Roosevelt called "muckrakers", described Nelson Aldrich of Rhode Island as the principal "traitor" among the "scurvy lot" in control of the Senate by theft, perjury, and bribes corrupting the state legislatures to gain election to the Senate. A few state legislatures began to petition the Congress for direct election of senators. By 1893, the House had the two-thirds vote for just such an amendment. However, when the joint resolution reached the Senate, it failed from neglect, as it did again in 1900, 1904 and 1908; each time the House approved the appropriate resolution, and each time it died in the Senate.


text: On the second national legislative front, reformers worked toward a constitutional amendment, which was strongly supported in the House of Representatives but initially opposed by the Senate. Bybee notes that the state legislatures, which would lose power if the reforms went through, were supportive of the campaign. By 1910, 31 state legislatures had passed resolutions calling for a constitutional amendment allowing direct election, and in the same year ten Republican senators who were opposed to reform were forced out of their seats, acting as a "wake-up call to the Senate".


text: Reformers included William Jennings Bryan, while opponents counted respected figures such as Elihu Root and George Frisbie Hoar among their number; Root cared so strongly about the issue that after the passage of the Seventeenth Amendment he refused to stand for re‑election to the Senate. Bryan and the reformers argued for popular election through highlighting flaws they saw within the existing system, specifically corruption and electoral deadlocks, and through arousing populist sentiment. Most important was the populist argument; that there was a need to "Awaken, in the senators... a more acute sense of responsibility to the people", which it was felt they lacked; election through state legislatures was seen as an anachronism that was out of step with the wishes of the American people, and one that had led to the Senate becoming "a sort of aristocratic body—too far removed from the people, beyond their reach, and with no special interest in their welfare". The settlement of the West and continuing absorption of hundreds of thousands of immigrants expanded the sense of "the people".


text: Hoar replied that "the people" were both a less permanent and a less trusted body than state legislatures, and moving the responsibility for the election of senators to them would see it passing into the hands of a body that "[lasted] but a day" before changing. Other counterarguments were that renowned senators could not have been elected directly and that, since a large number of senators had experience in the House (which was already directly elected), a constitutional amendment would be pointless. The reform was considered by opponents to threaten the rights and independence of the states, who were "sovereign, entitled... to have a separate branch of Congress... to which they could send their ambassadors." This was countered by the argument that a change in the mode in which senators were elected would not change their responsibilities.


text: The Senate freshman class of 1910 brought new hope to the reformers. Fourteen of the thirty newly elected senators had been elected through party primaries, which amounted to popular choice in their states. More than half of the states had some form of primary selection for the Senate. The Senate finally joined the House to submit the Seventeenth Amendment to the states for ratification, nearly ninety years after it first was presented to the Senate in 1826.


text: By 1912, 239 political parties at both the state and national level had pledged some form of direct election, and 33 states had introduced the use of direct primaries. Twenty-seven states had called for a constitutional convention on the subject, with 31 states needed to reach the threshold; Arizona and New Mexico each achieved statehood that year (bringing the total number of states to 48), and were expected to support the motion. Alabama and Wyoming, already states, had passed resolutions in favor of a convention without formally calling for one.


text: In 1911, the House of Representatives passed House Joint Resolution 39 proposing a constitutional amendment for direct election of senators. The original resolution passed by the House contained the following clause:


text: This so-called "race rider" clause would have strengthened the powers of states over senatorial elections and weakened those of Congress by overriding Congress's power to override state laws affecting the manner of senatorial elections.


text: Since the turn of the century, most blacks in the South, and many poor whites, had been disenfranchised by state legislatures passing constitutions with provisions that were discriminatory in practice. This meant that their millions of population had no political representation. Most of the South had one-party states. When the resolution came before the Senate, a substitute resolution, one without the rider, was proposed by Joseph L. Bristow of Kansas. It was adopted by a vote of 64 to 24, with four not voting. Nearly a year later, the House accepted the change. The conference report that would become the Seventeenth Amendment was approved by the Senate 42 to 36 on April 12, 1912, and by the House 238 to 39, with 110 not voting on May 13, 1912.


text: Having been passed by Congress, the amendment was sent to the states for ratification and was ratified by:


text: The Utah legislature rejected the amendment on February 26, 1913. No action on the amendment has been completed by Florida, Georgia, Kentucky, Mississippi, South Carolina, Virginia, Alaska or Hawaii. Alaska and Hawaii were not yet states at the time of the amendment's proposal, and have never taken any official action to support or oppose the amendment since achieving statehood.


text: Most importantly, the Seventeenth Amendment removed state government representation from the legislative arm of the federal government. Originally, the people themselves did not elect senators; instead, states appointed senators. The senators represented the states' interests, while the House of Representatives represented the interests of the people.


text: The Seventeenth Amendment altered the process for electing United States senators and changed the way vacancies would be filled. Originally, the Constitution required state legislatures to fill Senate vacancies.


text: According to Judge Bybee, the Seventeenth Amendment had a dramatic impact on the political composition of the U.S. Senate. Before the Supreme Court required "one man, one vote" in "Reynolds v. Sims" (1964), malapportionment of state legislatures was common. For example, rural counties and cities could be given "equal weight" in the state legislatures, enabling one rural vote to equal 200 city votes. The malapportioned state legislatures would have given the Republicans control of the Senate in the 1916 Senate elections. With direct election, each vote represented equally, and the Democrats retained control of the Senate.


text: The reputation of corrupt and arbitrary state legislatures continued to decline as the Senate joined the House of Representatives implementing popular reforms. Bybee has argued that the amendment led to complete "ignominy" for state legislatures without the buttress of a state-based check on Congress. In the decades following the Seventeenth Amendment, the federal government was enabled to enact progressive measures. However, Schleiches argues that the separation of state legislatures and the Senate had a beneficial effect on the states, as it led state legislative campaigns to focus on local rather than national issues.


text: New Deal legislation is another example of expanding federal regulation overruling the state legislatures promoting their local state interests in coal, oil, corn and cotton. Ure agrees, saying that not only is each senator now free to ignore his state's interests, senators "have incentive to use their advice-and-consent powers to install Supreme Court justices who are inclined to increase federal power at the expense of state sovereignty". Over the first half of the 20th century, with a popularly elected Senate confirming nominations, both Republican and Democratic, the Supreme Court began to apply the Bill of Rights to the states, overturning state laws whenever they harmed individual state citizens. It aimed to limit the influence of the wealthy.


text: The Seventeenth Amendment requires a governor to call a special election to fill vacancies in the Senate. It also allows a state's legislature to permit its governor to make temporary appointments, which last until a special election is held to fill the vacancy. Currently, all but five states (North Dakota, Oklahoma, Oregon, Rhode Island, and Wisconsin) permit such appointments. The Constitution does not set out how the temporary appointee is to be selected.


text: Oklahoma, admitted to statehood in 1907, chose a senator by legislative election three times: twice in 1907, when admitted, and once in 1908. In 1912, Oklahoma reelected Robert Owen by advisory popular vote.


text: Oregon held primaries in 1908 in which the parties would run candidates for that position, and the state legislature pledged to choose the winner as the new senator.


text: New Mexico, admitted to statehood in 1912, chose only its first two senators legislatively. Arizona, admitted to statehood in 1912, chose its first two senators by advisory popular vote. Alaska, and Hawaii, admitted to statehood in 1959, have never chosen a U.S. senator legislatively.


text: The first election subject to the Seventeenth Amendment was a late election in Georgia held June 15, 1913. Augustus Octavius Bacon was however unopposed.


text: In "Trinsey v. Pennsylvania" (1991), the United States Court of Appeals for the Third Circuit was faced with a situation where, following the death of Senator John Heinz of Pennsylvania, Governor Bob Casey had provided for a replacement and for a special election that did not include a primary. A voter and prospective candidate, John S. Trinsey Jr., argued that the lack of a primary violated the Seventeenth Amendment and his right to vote under the Fourteenth Amendment. The Third Circuit rejected these arguments, ruling that the Seventeenth Amendment does not require primaries.


text: Another subject of analysis is whether statutes restricting the authority of governors to appoint temporary replacements are constitutional. Vikram Amar, writing in the "Hastings Constitutional Law Quarterly", claims Wyoming's requirement that its governor fill a senatorial vacancy by nominating a person of the same party as the person who vacated that seat violates the Seventeenth Amendment. This is based on the text of the Seventeenth Amendment, which states that "the legislature of any state may empower the executive thereof to make temporary appointments". The amendment only empowers the legislature to delegate the authority to the governor and, once that authority has been delegated, does not permit the legislature to intervene. The authority is to decide whether the governor shall have the power to appoint temporary senators, not whom the governor may appoint. Sanford Levinson, in his rebuttal to Amar, argues that rather than engaging in a textual interpretation, those examining the meaning of constitutional provisions should interpret them in the fashion that provides the most benefit, and that legislatures' being able to restrict gubernatorial appointment authority provides a substantial benefit to the states.


text: Notwithstanding controversies over the effects of the Seventeenth Amendment, advocates have emerged to reform or repeal the amendment. Under President Barack Obama's administration in 2009, four sitting Democratic senators left the Senate for executive branch positions: Barack Obama (President), Joe Biden (Vice President), Hillary Clinton (Secretary of State), and Ken Salazar (Secretary of the Interior). Controversies developed about the successor appointments made by Illinois governor Rod Blagojevich and New York governor David Paterson. New interest was aroused in abolishing the provision for the Senate appointment by the governor. Accordingly, Senator Russ Feingold of Wisconsin and Representative David Dreier of California proposed an amendment to remove this power; senators John McCain and Dick Durbin became co-sponsors, as did Representative John Conyers.


text: Some members of the Tea Party movement argued for repealing the Seventeenth Amendment entirely, claiming it would protect states' rights and reduce the power of the federal government. On March 2, 2016, the Utah legislature approved Senate Joint Resolution No.2 asking Congress to offer an amendment to the United States Constitution that would repeal the Seventeenth Amendment. , no other states had supported such an amendment, and some politicians who had made statements in favor of repealing the amendment had subsequently reversed their position on this.


text: On July 28, 2017, after senators John McCain, Susan Collins and Lisa Murkowski voted no on Affordable Care Act repeal attempt Health Care Freedom Act, former Arkansas governor Mike Huckabee endorsed the repeal on the Seventeenth Amendment, claiming that senators chosen by state legislatures will work for their states and respect the Tenth Amendment, and also that direct election of senators is a major cause of the "swamp".


text: In September 2020, Senator Ben Sasse of Nebraska endorsed the repeal of the Seventeenth Amendment in a "Wall Street Journal" opinion piece.


title: Battle of the Denmark Strait

text: The Battle of the Denmark Strait was a naval engagement in the Second World War, which took place on 24 May 1941 between ships of the Royal Navy and the "Kriegsmarine". The British battleship and the battlecruiser fought the German battleship and the heavy cruiser , which were attempting to break out into the North Atlantic to attack Allied merchant shipping (Operation Rheinübung).


title: Battle of the Denmark Strait

text: Less than 10 minutes after the British opened fire, a shell from "Bismarck" struck "Hood" near her aft ammunition magazines. Soon afterwards, "Hood" exploded and sank within three minutes, with the loss of all but three of her crew. "Prince of Wales" continued to exchange fire with "Bismarck" but suffered serious malfunctions in her main armament. The British battleship had only been completed in late March 1941, and used new quadruple gun turrets that were unreliable. "Prince of Wales" soon broke off the engagement.


title: Battle of the Denmark Strait

text: The battle was a tactical victory for the Germans, but its impact was short-lived. The damage done to "Bismarck"'s forward fuel tanks forced the abandonment of the breakout and an attempt to escape to dry dock facilities in occupied France, producing an operational victory for the British. Incensed by the loss of "Hood", a large British force pursued "Bismarck", resulting in her loss three days later.


title: Battle of the Denmark Strait

text: In April 1941, the German "Kriegsmarine" intended to send the recently completed fast battleship into the Atlantic Ocean to raid the convoys carrying supplies from North America to Britain. The operation was intended to complement the U-boat attacks on British supply lines during the Battle of the Atlantic. The two fast battleships and had just completed a similar operation, code-named Berlin, between January and March that year. The number of major warships available to the Germans was limited; "Bismarck"s sister ship was not yet operational, "Scharnhorst" was in need of a boiler overhaul after Operation Berlin, and "Gneisenau" had been torpedoed while in Brest, France. Work on the heavy cruisers and , both under refit in Germany after their own raiding operations, was delayed by British air attacks that struck supply depots in Kiel. Admiral Günther Lütjens, the fleet commander who was to command German forces during the planned Operation Rheinübung, sought to delay until repairs to "Scharnhorst" were completed or "Tirpitz" could join "Bismarck", but the "Oberkommando der Marine" (Naval High Command) instructed Lütjens to begin the operation as soon as possible to keep pressure on Britain's supply lines. As a result, the only vessel available to support "Bismarck" was the heavy cruiser .


title: Battle of the Denmark Strait

text: The British Royal Navy learned of "Bismarck"s sortie after the Swedish cruiser spotted the vessels passing through the western Baltic Sea on 20 May; "Gotland"s report was passed to the British naval attache in Stockholm, who forwarded it to the Admiralty. British reconnaissance aircraft confirmed the Germans' presence in Norway. Now aware that major German warships were at sea with the intention to break into the Atlantic, the Royal Navy began to despatch vessels to patrol the likely routes, including the heavy cruisers and to cover the Denmark Strait between Greenland and Iceland. Another group, consisting of the battleship "Prince of Wales", the battlecruiser , and a screen of six destroyers, under the command of Vice-Admiral Lancelot Holland in "Hood", cruised to the south of Iceland to intercept the Germans once they were detected. "Norfolk" and "Suffolk" spotted "Bismarck" and "Prinz Eugen" on the evening of 23 May; "Suffolk" was fitted with radar that allowed them to shadow the Germans through the night whilst remaining outside of German gun range.


title: Battle of the Denmark Strait

text: "Prince of Wales" was a newly commissioned "King George V"-class battleship, similar to "Bismarck" in size and power. "Prince of Wales" had not yet been properly "shaken down", and her crew was inexperienced. She still had mechanical problems, especially with her main armament. The ship had sailed with shipyard workers still aboard working on her.


title: Battle of the Denmark Strait

text: For 20 years after her commissioning in 1920, "Hood" was the largest and heaviest warship in the world. Combining eight massive BL 15-inch Mk I naval guns with a top speed greater than any battleship on the sea, "Hood" was the pride of Great Britain's navy, and embodied the world dominance of British naval power. Despite this, "Hood" had one conspicuous flaw as compared to the super-dreadnought battleships she served alongside: as a battlecruiser, much of her bulk was dedicated to extra engine power instead of comprehensive armour coverage. This came from her design as a Admiral-class battlecruiser to meet the threat of the German "Mackensen"-class battlecruisers during World War I.


title: Battle of the Denmark Strait

text: While her 12-inch belt armour was considered sufficient against most capital ships she was likely to encounter, her 3 inches of deck armour left her vulnerable to plunging fire at long range. At the time of her commissioning in World War I, naval gunnery was severely inaccurate at the ranges necessary to produce plunging fire, and "Hood's" greater speed and maneuverability were seen as an acceptable trade-off. However, as the accuracy of naval gunfire increased in the inter-war period, "Hood" was eventually scheduled to receive an upgrade in 1939 that would have doubled her deck armour to 6 inches, but the outbreak of World War II meant the upgrade never took place. She thus sortied to war at a marked disadvantage against the new capital ships of the Axis powers.


title: Battle of the Denmark Strait

text: Aware of "Hood"'s inadequate protective armour, distant to the southeast of where the battle took place, Holland's superior (Admiral Sir John Tovey) considered ordering him to have "Prince of Wales" sail ahead of "Hood". With the ships in this position, Tovey concluded the better-protected "Prince of Wales" could draw the German battleships' large-shell gunfire. Ultimately, Tovey did not give the order, later saying "I did not feel such interference with such a senior officer justified."


title: Battle of the Denmark Strait

text: The "Kriegsmarine" had hoped that the "Bismarck" force would enter onto trans-Atlantic commerce raiding, from the Norwegian Sea via the Denmark Strait, undetected and unopposed. The Germans based this hope upon a transit from German territorial waters on the North Sea; and, through the territorial waters of German-occupied Norway into the Norwegian Sea, undetected by aerial searches; neutral ship encounters; and traditional "coast-watching" observations performed by formal and informal efforts of maritime intelligence gathering, in the neutral and occupied countries surrounding the North Sea.


title: Battle of the Denmark Strait

text: In the event, the ground-level coast-watching observations from both neutral and occupied territories identified the principal combatant units sortied for the Exercise Rhine operation from the moment they left German territorial waters. The combatants ("Bismarck" and "Prinz Eugen") were identified by in-country coast-watchers located in Denmark; who were able to identify the ships and communicate with their clandestine contacts, the dates and times of the German surface units, moving in their designated coast-watch areas of responsibility.


title: Battle of the Denmark Strait

text: The ships of neutral Sweden acknowledged the transit of the main combatants in the normal shipping lanes in the North Sea, and reported on them in their normal routine to their maritime authorities. Swedish territory as well hosted individual ground-level coast watchers who were able to follow and report on movements in Swedish coastal waters. These observations were passed directly to Royal Navy intelligence by routine maritime diplomatic channels maintained by the British naval attaché in Stockholm. Thus, when "Bismarck" and her escort moved into the unoccupied fjords of German-occupied Norway, for final coastal refuelling and topping off of ships' stores and supplies, the RAF (weather permitting) was able to keep a final watch on the location and timing of the German raider force.


title: Battle of the Denmark Strait

text: Holland's battle plan was to have "Hood" and "Prince of Wales" engage "Bismarck" while "Suffolk" and "Norfolk" engaged "Prinz Eugen" (which, Holland assumed, still steamed behind "Bismarck" and not ahead of her). He signalled this to Captain John C. Leach of "Prince of Wales" but did not radio Wake-Walker, who as Commander of the 1st Cruiser Squadron directed "Suffolk" and "Norfolk", for fear of disclosing his location. Instead, he observed radio silence. Holland hoped to meet the enemy at approximately 02:00. Sunset in this latitude was at 01:51 (ship's clocks were four hours ahead of local time). "Bismarck" and "Prinz Eugen" would be silhouetted against the sun's afterglow while "Hood" and "Prince of Wales" could approach rapidly, unseen in the darkness, to a range close enough not to endanger "Hood" with plunging fire from "Bismarck". The Germans would not expect an attack from this quarter, giving the British the advantage of surprise.


title: Battle of the Denmark Strait

text: The plan's success depended on "Suffolk"s continually unbroken contact with the German ships. However, "Suffolk" lost contact from 00:28. For 90 minutes, Holland neither sighted the German ships nor received any further news from "Norfolk" or "Suffolk". Reluctantly, Holland ordered "Hood" and "Prince of Wales" to turn south-southwest but he detached his destroyers which continued searching to the north. However, the loss of contact should be understood as temporary and tactical only; and not strategic in terms of the tactical outcome. "Suffolk" lost contact with its reconnaissance target (the enemy fleet) in what was essentially a closed, confined rectangular space; aligned generally northeast (the entrance to the Denmark Strait) to southwest (the exit of the Strait into the Atlantic). The enemy units were firmly constrained by the Greenland ice pack to the north, and the extensive Royal Navy minefield to the south along the coast of Iceland. Given the prior warning of the German sortie, there was ample time for the Royal Navy to place armed reconnaissance at both ends of this narrow alignment. "Suffolk" and "Norfolk" were at the eastern entrance to the Strait (where contact was made immediately upon "Bismarck"s entry). Holland was waiting at the western end as the "Bismarck" force exited the Strait.


title: Battle of the Denmark Strait

text: Strategically, it was an unquestioned fact (including the approximate timing) that "Bismarck"s and "Prinz Eugen"s entrance into the Atlantic (the fundamental objective of Rhine Exercise), was known from the moment the fleet left German territorial waters. And that was a long enough time span before the fleet's final fitting out for transit to the Denmark Strait, that Lütjens could not have helped but to realize, that his force would not under any circumstance enter the Atlantic undetected nor would it enter unopposed. And by the time it was opposed, it would occur with forces that would likely ensure his fleet's ultimate destruction. And such destruction would take place before any supply convoy units (the whole purpose of the operation) were threatened by Operation Rhine Exercise.


title: Battle of the Denmark Strait

text: Before contact was re-established, the two squadrons missed each other narrowly. Had the German ships not altered course to the west at 01:41 to follow the line of the Greenland icepack, the British would have intercepted them much earlier than they did. The British destroyers were just to the southeast when the Germans made this course change. If the visibility had not been reduced to , the German vessels would probably have been spotted (since generally on a calm, clear day ship lookouts can observe large objects and ships about 12 miles (19 km) distant on the horizon. And if the ship's lookouts are in a crow's nest, the observable distance is even farther).


title: Battle of the Denmark Strait

text: Just before 03:00, "Suffolk" regained contact with "Bismarck". "Hood" and "Prince of Wales" were away, slightly ahead of the Germans. Holland signalled to steer toward the Germans and increased speed to . "Suffolk"s loss of contact had placed the British at a disadvantage. Instead of the swiftly closing head-on approach Holland had envisioned, he would have to converge at a wider angle, much more slowly. This would leave "Hood" vulnerable to "Bismarck"s plunging shells for a much longer period. The situation worsened further when, at 03:20, "Suffolk" reported that the Germans had made a further course alteration to the west, placing the German and British squadrons almost abeam of each other.


title: Battle of the Denmark Strait

text: At 05:35, lookouts on "Prince of Wales" spotted the German ships away. The Germans, already alerted to the British presence through their hydrophonic equipment, picked up the smoke and masts of the British ships 10 minutes later. At this point, Holland had the options of joining "Suffolk" in shadowing "Bismarck" and waiting for Tovey to arrive with "King George V" and other ships to attack, or ordering his squadron into action. He chose the latter at 05:37. The rough seas in the Strait kept the destroyers' role to a minimum and the cruisers "Norfolk" and "Suffolk" would be too far behind the German force to reach the battle.


title: Battle of the Denmark Strait

text: "Hood" opened fire at 05:52 at a distance of approximately . Holland had ordered firing to begin on the leading ship, "Prinz Eugen", believing from her position that she was "Bismarck". Holland soon amended his order and directed both ships to engage the rear ship, "Bismarck". "Prince of Wales" had already identified and engaged "Bismarck", whereas "Hood" is believed to have continued to fire at "Prinz Eugen" for some time.


title: Battle of the Denmark Strait

text: Holland was a gunnery expert; he was well aware of the danger posed by "Hood"s thin deck armour, which offered weak protection against vertical plunging fire. Holland therefore wanted to reduce the range as quickly as possible, because at a shorter range the trajectory of "Bismarck"s shells would be flatter, and the shells would therefore be more likely to hit the armour belt protecting the sides of the ship or glance off the top deck, rather than penetrate vertically though the deck armour. Holland closed the range at an angle that placed the German ships too far forward of the beam, which meant that only 10 of the 18 British heavy guns could train and presented the Germans with a bigger target than necessary. One of "Prince of Wales" forward guns became unserviceable after the first salvo, leaving only 9 still firing. "Suffolk" and "Norfolk" tried to engage "Bismarck" during the action but both were out of range and had an insufficient speed advantage over "Bismarck" to rapidly close the range.


title: Battle of the Denmark Strait

text: The Germans also had the weather gauge, meaning that the British ships were steaming into the wind, with spray drenching the lenses of "Prince of Wales"' "A" turret's Barr and Stroud coincidence rangefinder and both British ships' "B" turret rangefinders. The shorter based () ones in the director towers had to be used instead. Holland had "Prince of Wales" stay close to "Hood", conforming to "Hood"s movements instead of varying course and speed, which made it easier for the Germans to find the range to both British ships. It would have aided Holland's gunners if they had both fired upon "Bismarck" as originally planned, since they could time precisely each other's salvos to avoid mistaking one ship's fire for the other. The British could also use "Concentration Fire", where both ships' main armament salvos would be controlled by one ship's fire control computer—probably "Prince of Wales" modern Admiralty Fire Control Table.


title: Battle of the Denmark Strait

text: "Prince of Wales" struck her target first. She would ultimately hit "Bismarck" three times. One shell struck the commander's boat and put the seaplane catapult amidships out of action (the latter damage not being discovered until much later, during an attempt to fly off the ship's War Diary on the eve of her final battle). The second shell passed through the bow from one side to the other without exploding. The third struck the hull underwater and burst inside the ship, flooding a generator room and damaging the bulkhead to an adjoining boiler room, partially flooding it. The last two hits caused damage to "Bismarck"s machinery and medium flooding. The hit also severed a steam line and wounded five of "Bismarck"'s crew by scalding. The damage to the bow cut access to of fuel oil in the forward fuel tanks, caused "Bismarck" to leave an oil slick and reduced her speed by . "Bismarck" was soon listing 9° to port and lost of freeboard at her bow.


title: Battle of the Denmark Strait

text: The Germans held their fire until 05:55, when both German ships fired on "Hood". Lütjens did not immediately give the order to begin firing. "Bismarck"s first gunnery officer, "Korvettenkapitän" Adalbert Schneider, asked "" (Permission to open fire?) several times without receiving a response, until the captain of "Bismarck, " "Kapitän zur See" Ernst Lindemann, impatiently responded: "" (I'm not letting my ship get shot out from under my arse. Open fire!)


title: Battle of the Denmark Strait

text: A shell hit "Hood"s boat deck, starting a sizable fire in the ready-use ammunition store but this fire did not spread to other areas of the ship or cause the later explosion. It is possible that "Hood" was struck again at the base of her bridge and in her foretop radar director. There has been contention over which German vessel struck "Hood"; "Prinz Eugen" ("Kapitän zur See" Helmuth Brinkmann), was firing at "Prince of Wales", following an order from the fleet commander. The Gunnery Officer of "Prinz Eugen", Paul Schmalenbach is quoted as saying that "Prinz Eugen"'s target was "Hood".


title: Battle of the Denmark Strait

text: At 06:00, Holland ordered his force to turn once again to port to ensure that the aft main guns on both "Hood" and "Prince of Wales" could bear on the German ships. In terms of the force balance this would nominally give Holland's force the advantage of 18 large caliber (14/15 in.) guns (10 in "Prince of Wales", 8 in "Hood"); to 8 (8 - 15 in. in "Bismarck").


title: Battle of the Denmark Strait

text: During the turn, a salvo from "Bismarck", fired from about , was seen by men aboard "Prince of Wales" to straddle "Hood" abreast her mainmast. This straddle meant that some of the salvos fell to port, some to starboard (of the hull), and some precisely aligned over the center of the main deck of "Hood". It is likely that one shell struck somewhere between "Hood"s mainmast and "X" turret aft of the mast. A huge pillar of flame shot upward 'like a giant blowtorch' in the vicinity of the mainmast.


title: Battle of the Denmark Strait

text: This was followed by an explosion that destroyed a large portion of the ship from amidships clear to the rear of "Y" turret, blowing both after turrets into the sea. The ship broke in two and the stern fell away and sank. Ted Briggs, one of the survivors, claimed "Hood" heeled to 30 degrees at which point 'we knew she just wasn't coming back'. The bow rose clear of the water, pointed upward, pivoted about and sank shortly after the stern. "A" turret fired a salvo while in this upright position, possibly from the doomed gun crew, just before the bow section sank.


title: Battle of the Denmark Strait

text: Splinters rained down on "Prince of Wales" away. "Hood" sank in about three minutes with 1,415 members of the crew. Only Ted Briggs, Bob Tilburn and Bill Dundas survived to be rescued two hours later by the destroyer .


title: Battle of the Denmark Strait

text: The Admiralty later concluded that the most likely explanation for the loss of "Hood" was a penetration of her magazines by a shell from "Bismarck", causing the explosion. Recent research with submersible craft suggests that the initial explosion was in the aft magazine and that it spread to the magazines via the ammunition trunks. It has been suggested from examination of the wreckage, found in 2001, that the magazine explosion in the armament near the mainmast caused the vertical blast of flame seen there, and this in turn ignited the magazines of the aft guns that caused the explosion that wrecked the stern. This explosion might have travelled through the starboard fuel tanks, igniting the fuel oil there, setting off the forward magazines and completing the destruction of the ship.


title: Battle of the Denmark Strait

text: The wreck of "Hood" revealed the bow section bereft of any structure. A huge section of her side is missing, from the 'A' barbette to the foredeck. The midship section had its plates curled outward. Moreover, the main parts of the forward structure, including the conning tower, were found about away from the main wreckage. This has sparked theories that the forward magazines exploded as a result of the force, flames and pressure, caused by the detonation of the aft magazines. However, a team of marine forensic scientists has found that implosion damage to the forward hull due to the rapid sinking of the "Hood", is the most likely cause of the state of the forward hull, and they do not support any theory that the forward magazines exploded.


title: Battle of the Denmark Strait

text: "Prince of Wales" found herself steering towards the sinking "Hood". Her commanding officer, Captain Leach, ordered an emergency avoidance turn away from "Hood"s wreckage. This violent change of course disrupted her aim and put her in a position that made it easier for the Germans to target her. She resumed her previous course but was now under the concentrated fire of both German ships. "Prince of Wales" was struck four times by "Bismarck" and three times by "Prinz Eugen". One shell passed through her upper superstructure, killing or wounding several crewmen in the Compass Platform and Air Defence Platform. Pieces of another shell struck her radar office aft, killing the crewmen within.


title: Battle of the Denmark Strait

text: A shell from "Prinz Eugen" found its way to the propelling charge/round manipulation chamber below the aft gun turrets, and a shell from "Bismarck" hit underwater below the armour belt, penetrating about into the ship's hull, about below the waterline, but was stopped by the anti-torpedo bulkhead. Fortunately for "Prince of Wales", neither shell exploded, but she still suffered minor flooding and the loss of some fuel oil. Contrary to some mistaken opinion, the shell that struck "Prince of Wales" below the waterline did not endanger her magazines, as it came to rest abreast an auxiliary machinery room.


title: Battle of the Denmark Strait

text: By this time, serious gunnery malfunctions had caused intermittent problems with the main armament, leading to a 26% reduction in output. According to Captain Leach, he decided that continuing the action would risk losing "Prince of Wales" without inflicting further damage on the enemy. He, therefore, ordered the ship to make smoke and withdraw, 'pending a more favourable opportunity'. "Prince of Wales" turned away just after 06:04, firing from her rear turret under local control until the turret suffered a jammed shell ring, cutting off the ammunition supply and making the guns inoperable.


title: Battle of the Denmark Strait

text: Despite efforts by crew members and civilian technicians to repair the shell ring, it took until 08:25 for all four guns to be back in service, although two of the guns were serviceable by 07:20. This temporarily left only five guns operational, but nine of the ten were operational in five hours. The final salvos fired were ragged and are believed to have fallen short. The ship retired from the battle around 06:10. Thirteen of her crew had been killed, nine were wounded. The timing of "Prince of Wales" withdrawal was fortunate for her, as she had come into torpedo range of "Prinz Eugen" and turned away as the German cruiser was about to fire.


title: Battle of the Denmark Strait

text: On "Bismarck" there was tremendous elation at the sinking of "Hood". There was also a keen expectation that they would close on "Prince of Wales" and possibly finish her off. Lindemann requested that Lütjens allow "Bismarck" to do just that. Even if Tovey's squadron had left Scapa Flow the previous day, he would still be more than away from "Bismarck" – even if "Bismarck" diverted to sink "Prince of Wales" (a chase Lindemann calculated would take only two or three hours).


title: Battle of the Denmark Strait

text: Lütjens refused to allow Lindemann to give chase, giving no explanation. Lindemann repeated his request, this time more assertively. Lütjens held firm orders from the German Naval Commander, "Großadmiral" Erich Raeder, to avoid unnecessary combat with the Royal Navy, especially when it could lead to further damage that could hasten delivering "Bismarck" toward the waiting hands of the British. He broke off combat instead of pursuing "Prince of Wales" and ordered a course of 270°, due west. "Bismarck" had fired 93 of her 353 base-fused Armour Piercing (AP) shells during the engagement.


title: Battle of the Denmark Strait

text: This clash between the two senior German officers reflected their disparate and distinct command functions. As captain of "Bismarck", Lindemann operated first and foremost as a tactician. As such, he had no doubt that his ship's immediate objective was to destroy "Prince of Wales", and he had pressed his case as far and hard as he should. Lütjens, as fleet chief and task force commander, operated at the strategic and operational levels. To some degree, his orders were clear – attacking convoys was his priority, not risking "a major engagement for limited, and perhaps uncertain, goals". Nevertheless, Raeder had also ordered Lütjens to be bold and imaginative, to accept battle if unavoidable and conduct it vigorously to the finish.


title: Battle of the Denmark Strait

text: The reality was that Lütjens' orders did not cover a spectacular success like the one just achieved. His priority therefore was to stick to his instructions - to concentrate on sinking merchant shipping and avoid encounters with enemy warships whenever possible. Moreover, before leaving Germany, Lütjens had told Admirals Conrad Patzig and Wilhelm Marschall, that he would adhere to Raeder's directives. This meant he did not intend to become the third fleet chief to be relieved for contradicting Raeder's orders; Marschall, one of his two predecessors, had been relieved of command for not following his orders to the letter despite the fact that Marschall's analysis of the changes in the tactical situation since the orders were issued resulted in the sinking of the British aircraft carrier and its two escorting destroyers. Nor was he predisposed to discuss his command decisions with a subordinate officer.


title: Battle of the Denmark Strait

text: Even if he had known it was the untried "Prince of Wales" he was fighting and not "King George V", Lütjens would probably have stuck to his decision. Following her would have meant exposing the squadron to further gunfire as well as to torpedo attacks from "Norfolk" and "Suffolk". He would have risked his ships and crews on an expressly forbidden opportunity. Lütjens would also have been facing a foe that was still combat effective, despite the hits taken the RN's damage assessment was that damage sustained was limited and caused no significant reduction in combat efficiency.


title: Battle of the Denmark Strait

text: Between 06:19 and 06:25, "Suffolk" fired six salvoes in the direction of "Bismarck", having mistaken a radar contact with an aircraft for "Bismarck". "Suffolk" was actually out of gun range of both "Bismarck" and "Prinz Eugen" at the time.


title: Battle of the Denmark Strait

text: Holland's death led to responsibility for "Prince of Wales" falling to Wake-Walker in "Norfolk". With this command came the responsibility of coping with "Bismarck" until enough British warships could concentrate and destroy her. His choice was either to renew the action with "Bismarck", or ensure that she be intercepted and brought to action by other heavy units. Wake-Walker chose the latter course, continuing to shadow the German ships. Further offensive action, he concluded, would cause more damage to "Prince of Wales" than to "Bismarck" and endanger his cruisers, plus he knew Tovey was on his way. He ordered "Prince of Wales" to follow "Norfolk" at her best speed, so that "Norfolk" and "Suffolk" could fall back on her if attacked. At 07:57 "Suffolk" reported that "Bismarck" had reduced speed and appeared damaged.


title: Battle of the Denmark Strait

text: Since "Bismarck"s receiving the first hit in the forecastle, all six of the ship's 26-man damage control teams had worked to repair the damage. When it was reported that the tips of the starboard propeller could be seen above water, Lindemann had ordered counterflooding two compartments aft to restore the ship's trim. He then sent divers into the forecastle to connect the forward fuel tanks, containing a much-needed of fuel, first to the tanks near the forward boiler then to the rear fuel tank by way of a provisional line running over the upper deck.


title: Battle of the Denmark Strait

text: Both these manoeuvres failed. Lindemann then requested permission to slow "Bismarck" and heel the ship first to one side then the other to weld patches from the inside to the holes in the forward hull. Lütjens refused, again without comment. Eventually, he had to agree to slow the ship to to allow hammocks and collision matting to be stuffed in the holes of the No. 2 boiler room and the auxiliary boiler room to stop the growing ingress of seawater. This attempt also failed. Boiler Room No. 2 was shut down, with a loss of speed to .


title: Battle of the Denmark Strait

text: As well as taking on seawater, "Bismarck" was leaking fuel oil. Lütjens ordered "Prinz Eugen" to drop back and see how much of a trail she was leaving astern. The carpet of oil was broad enough to cover both sides of the ship's wake, was all colours of the rainbow and gave off a strong smell – all of which helped disclose "Bismarck"s location.