Hi, my name's Andy and in this video we're going to be looking at the latency that we can get when running videos over a 2110 network. Now, if you're fairly new to the idea of video over 2110, one of your reservations might be that you're a little bit worried about the latency, that you can have a lot of delay. It's going to be really hard to get things synchronized up. So what we've done here, we've created a little setup so that you can actually see what happens and what the latency actually is. And spoiler alert, it's not going to be a problem. This is not a scientific setup. We're not looking to precisely define the amount of latency in nanoseconds. This is just to give you an idea of what kind of latency you can expect in a practical situation. So just to explain what we have here, I have a little video splitter. So I have a signal coming in via HDMI and then it comes out twice as an SDI signal. Once with the blue dot on the cable going into the blue dot monitor, which if I disconnect turns off and then again with the cable with the red dot going into the red dot monitor. Now if I disconnect this cable, then there's no signal coming in here. So nothing being displayed on the screen down there. And I have here two fusions, which are part of our media net IP range. Now this fusion is encoding the SDI signal as 2110, and this fusion is decoding the 2110 signal into SDI. So I'm going to take the SDI signal coming out of the splitter and feed it into the encoder. I'm simply going to plug the SDI cable in here, and then once it's in, then the signal comes out of the splitter. Once goes to this monitor here. As you can see, the other signal is going through the cable into the fusion, which is then encoding it, sending it via the fiber to our switch. And then it goes through the switch out of this fiber into this fusion device. And then we get an SDI signal, which comes out of here. So if I take this SDI cable, which remember is connected to this monitor, I plug it in to the output of the fusion, then the signal we get here is exactly the same signal as it's coming from our video player. But now instead of going the direct route over the cable from the splitter to the screen, it's actually going from the splitter to the encoder into the switch, back out to the decoder, and then into the monitor. And we've taken a slow-mo camera, which is filming the two screens side by side. So you can see what the difference is with the frame count between the video that is going directly and the video that is going over the IP system. Now, a couple of things to be aware of when you're looking at the results of this. So as you can see here with a slow-mo of the direct connection, we're going from frame to frame. Now, this video was originally encoded in 50 frames per second. And here our player is playing it at 25 frames per second, which explains why you can only see the even frame numbers. Secondly, if you're dealing with a big network, you are going to see slightly more latency. Here we're running both devices off the same switch. Typically per switch, you can expect to have about five microseconds of latency. So if you're dealing with a big network, then you could start to notice that. In this case, we only have the one switch. And obviously any big network does depend on PTP for the synchronization between the devices. So there are other things that you need to think about, but with a very simple setup here, you can see what kind of delay you can realistically expect.


The Appalachian Advantage plan is the simpler, better way to get the phone you actually want instead of paying hundreds of dollars up front.  It's called the Appalachian Advantage available at Appalachian Wireless. The Auxure Volunteer Fire Department will be holding their annual Haunted Hay Ride starting Friday, October 14th. It wouldn't be scary if I told you everything. We're going to have probably 60 people up the holler. They'll be doing graveyards and witches and clowns and a number of things. Due to the summer's flooding, the Hay Ride had to be moved to the Jenny Wiley State Resort Park. However, in moving, the Hay Ride became longer than years past. We have been doing the Hay Ride in the campground probably for 12 to 15 years, but since the flooding and so many campers are over there with the people that were displaced, we had to find a new place. Tickets for the Hay Ride are $10 for adults and $5 for children. Food vendors will also be present at the Hay Ride. For more information about the event, you can visit the A-V-F-D Haunted Hay Ride event page on Facebook. For Mountain Top News, I'm Kelsey Dean.


Welcome myself, Girdhar Jain, Assistant Professor in Electronics and Telecommunication Engineering, Valchan Institute of Technology, Solapur. Now, today I am going to deliver a lecture on short channel effect in eMOSFET. Now, learning outcomes of the session are at the end of the session, students will be able to describe a short channel effect in eMOSFET. So, this is VI characteristics of eMOSFET. So, the figure shown on the left hand side is the circuit used for simulation. Phi gs is varied from 1 to 5 volt and between drain and source, phi ds varied from 0 to 5 volts. So, this is diagram used for simulation. And on the right hand side you can see the characteristics, drain characteristics, ids versus phi ds for different values of phi gs, phi gs 1, 2, 3, 4 and 5. And this dotted line is boundary that is phi gs minus phi t is equal to phi ds. Towards left hand side is the non-saturation or linear region. On the right hand side of the dotted line is saturation region. And for phi gs less than or equal to phi t, that is your cutoff region. So, that part already we have studied. Now, let us understand this short channel effect. Now, if length of channel is large, then the short channel effect is negligible. But if length of channel is small, then this effect is not negligible. So, here you can see the part of construction of each channel MOSFET. So, E MOSFET that is N channel. So, P substrate, then 2 heavily doped N regions N plus N plus 1 is right hand side is drain. This is source and in between drain and source insulating layer of SiO2. And through polysilicon material it is connected to the gate as shown in figure. Now, generally the substrate is connected to the source. And we apply positive voltage between drain and source for N channel E MOSFET. Now, if substrate is connected to the source, then substrate goes to the ground. And positive voltage will be applied between N plus drain N type drain and the P type substrate. So, here a P N junction is formed. And as the N is connected to positive and the substrate P is connected to negative, a P N junction formed between drain and substrate is reverse bias. Now, if V DS is increased, what will happen? The reverse bias voltage will gone increasing and a depletion layer is formed between this P N junction between the drain and substrate as shown in figure. And as V DS is increased, this depletion layer penetrates into the substrate and it penetrates into the channel. Thereby, the effective length of channel is reduced as shown in figure and it is L effective. So, this is a short channel effect. Means, if V DS is increased, the depletion layer which is formed at the drain and substrate is penetrated into the channel and thereby reducing the effective length of channel for the conduction. Then I DS in this saturation region is given by beta V DS minus V T bracket square by 2. And for saturation region, the condition is V DS minus V T greater than 0 and less than V DS. Where beta is mu epsilon upon T O X W by L, where mu is mobility, epsilon is permittivity insulating layer, T O X is the thickness of oxide layer, W is width of channel and L is length of channel. Now, L effective is given by L effective is equal to L minus L short. L short is shown in the previous diagram. This is L short and this L short is given by L short is equal to square root of 2 epsilon Si divided by Q into N A in the bracket V DS minus in the another bracket V DS minus V T bracket close bracket close. So, this is L short. So, epsilon is the permittivity of Si O 2 permittivity of Si then Q into N A in the bracket V DS voltage between drain and source V GS minus V T, V T is threshold voltage. And due to this short channel effect, it is so according to short channel effect, what will happen? Due to increase in V DS, length of channel is reduced. As the length of channel is reduced. So, there is increase in drain current. There is increase in drain current and this is given by the equation I DS is equal to beta by 2 in the bracket V GS minus V T square into another bracket 1 plus lambda into V DS. Original equation is beta by 2 in the bracket V GS minus V T square. That is in saturation region. So, due to short channel effect, the second bracket 1 plus lambda into V DS is added. Where lambda is the channel length modulation factor and its value is given by 0.0 it value is 0.02 V raise to minus 1 2 0.005 V raise to minus 1. So, this is the range of lambda. So, lambda is short channel length modulation factor. Now pause this video and think on the following. Shall we obtain the value of lambda? Knowing the device characteristics, the value of lambda can be obtained as shown in figure. So, figure shows the VI characteristics for the N channel E MOSFET. So, ID versus V DS for different values of V GS. So, here V DS minus V T 2 whole then V DS minus V T 4 whole, 4 whole, 8 whole. So, these are given. And for this, now if you extend these characteristics in the form of dotted line. So, all the dotted line, there are four dotted lines of the four characteristics and they will meet at one point which is minus V A. And this minus V A is equal to minus 1 by lambda. Means you can obtain lambda is equal to 1 by V A, lambda is equal to 1 by V A. So, in this way the value of lambda can be obtained. And once the lambda is obtained, you can estimate for the increase in drain current due to short channel effect. So, in summary, a short channel effect is nothing but due to increase in V DS. The depletion layer formed at between drain and substrate is penetrated into the channel and effective length of channel is reduced. And thereby there is a increase in the drain current with increase in V DS in the saturation region. So, this is a short channel effect. Now, the advantage of the short channel effect that area of MOSFET is reduced. Hence, more number of MOSFETs are fabricated per unit area means large integration. And gain of MOSFET is increased, so more drain current. And the disadvantage is if V DS is increased, then get loses the control over IDS. So, this is a short channel effect. So, these are the references, principle of CMOSVLSI design, NEL, Weste and Kamran Isirjian person education. And secondly is electronic design by Martin Rodden and others. Thank you for watching the video.


We celebrated some birthdays last month. I had a big one and square turned 12 Now you might know square as the little white card reader that plugs into cell phones that lets you take payments on the go but we've actually developed a suite of hardware solutions to help merchants take payments and A suite of software to help merchants manage their business and that software is called dashboard and This is what dashboard looks like Merchants use dashboard to keep track of their business They can see their payment activity. They can send invoices and they can run payroll Dashboard is the home base for square sellers And dashboard is an ember monolith Today i'm here to talk to you about modernizing our massive ember monolith dashboard My name is abry newton and here i am at ember conf in 2018 with tomster and zoe I have been working with ember for about five years Two years in our dashboard application and three years in a separate application That was a greenfield app and it's a little more modern because it was newer I have been participating in code upgrades and migrations and dashboard and have recently been driving engine adoption from a product team not an infrastructure team role And i'm here to convince you that you can build ambitious web applications with ember that stand the test of time Today I will convince you that with ember you can build for the long term Ember apps can be used for years almost a decade in our case This is important because time is a finite resource When we at square have done the analysis in the past a rewrite is always more expensive than the proposed upgrades By spending less time on total rewrites, we're able to spend more time Working on features for our customers and there's less chance of regression And finally when we stick with ember, we're able to build knowledge and expertise in our engineers That is long lasting rather than changing frameworks every couple of years Our engineers become fluent in ember which makes them more productive over the long term Today we'll convince you that with ember you can build resilient apps Ember apps can be used by tens of thousands of people every day and have hundreds of developers contributing because we've seen this in our app And today we'll convince you that with ember you can build apps that evolve We built an app in 2011 and now in 2021 we are using 2021 web technology in fundamentally the same app So long as you're on the standard ember path ember makes upgrading easy via documentation and semantic versioning Long-term support or LTS releases, which are versions of ember that receive security updates for an extended time after their release And code mods and lints Code mods are tools that automatically make the tedious syntax changes to your code that you would normally have to do manually Code mods can help ensure that you are using the latest patterns and platform features And lints are static code analysis tools used to flag programming errors bugs stylistic errors and suspicious constructs and they often use code mods to automatically fix violations in code But even in applications with weird wear Which i define as deprecated packages or experiments in code where we've strayed from the standard ember path those times You know when we've decided to roll our own It's possible to stay current with some effort Even in a massive application We've done this over the last 10 years Our app has a dedicated team that runs most of our upgrades which helps a lot But they do it in conjunction with product teams because they don't know how everything in the app works Um, but upgrading is possible even without a dedicated team Though it will be easier if you don't use any weird wear In a much smaller more standard app. I was a dedicated upgrade team in addition to my product feature responsibilities So this is the story of square dashboard To give you some context This is the commit visualization of the last almost eight years that dashboard has been in its own repository And to give you a sense of scale in 2020 We had an average of 140 developers contributing every quarter with an average of 1500 commits per quarter And by my count, we've had over 600 individuals contribute to this code base at one point or another in their careers at square But this isn't 100 percent my story to tell I joined in 2016 and then I switched to a non dashboard ember team for about three years and came back to dashboard in 2020 Several of my co-workers helped me write this talk and I want to thank them for that So let me take you back now to 2010 Wow, do you remember what the web looked like in 2010? I honestly didn't until I saw this screenshot At this point for square our main product was swiping a card on your phone and emailing our texting or receipt instantly In 2011 we have a slightly newer looking website. It's still very simple though You can take a payment you can see your balance and you can see when your balance will be paid out to your bank account And in november of 2011 we introduced sprout core one Which was a precursor to sprout core two, which was later renamed to ember In our ruby mono repo next to our urb templates and the commit message for this says first day of hacking And that's exactly what it was. It was basically 100 lines of script tags in 2012 We had what we considered sort of our logged in web Payment experience. It's so cute, right the buttons have shading and depth Um, this is the view layer of our original square rails app There's a simple trap of transactions and you can click to view your receipt details And you can filter your transactions by date In 2013, uh, we started to break up our web properties into separate apps Dashboard was already getting too big and slow and early code sharing via gems and get sub modules didn't work well And so we moved dashboard into its own repository And it was a rails app and we were using ember rails and we added ember version 1.0.0. rc3.4 How's that for a version number? And in 2013 our app has some tabs across the top adding more functionality as we are developing more features In 2014 we did a total redesign in css rewrite And now this is where it starts looking much more like the modern web to me And as you can see we continue to add features across the top In 2015 in january, we upgraded to ember 1.7 and for reference 1.7 was released in august of 2014 At this point in time upgrading wasn't a big priority for square and we didn't have a team primarily focused on doing it Um, this is also where we decided to start looking at our dashboard navigation project and figuring that out But other than that there is not a lot going on at the moment with the ember framework and dashboard We're busy building features. Uh, for example, we built and launched a square payroll Ember wasn't being super high maintenance and it just kind of faded into the background In 2016 in january ember is still on 1.7 and dashboard And then in june ember 1.13 lands And it was that was launched to the community in june of 2015 for about a year behind But luckily we didn't get stuck on 1.12 So when I joined in august we were on ember 1.13 and I am told I dodged a bullet because I showed up late in math Or maybe I showed up right on time In any case a lot of people had a bad experience upgrading to ember 1.13 because it was really painful And ember maintainers learned from that experience and they try not to do that anymore and they tried to make upgrades a lot easier 2016 was a year of more features Everything at this point was written in coffee script That's because when we started dashboard in 2012 javascript was a very different language You know es5 didn't exist es6 was introduced in 2015 And so coffee script was created to as an attempt to expose the good parts of javascript in a simple way And the code compiled one-to-one the equivalent javascript and there was no interpretation at runtime And so coffee script was the web the way to write web applications easily and that's what we were using But by 2016 We have es6 and so we're starting to add new code and javascript and and at the same time we were encouraging component use in ember Components had been available starting in 1.0, but we sprout core folks held on to the mvc structure a little longer And so for me in 2016 I was learning ember I was learning es6 syntax and I built this cute component that shows you your subscriptions and your monthly charges And in december we upgraded dashboard to ember 2.0, which had been released in august of 2015 That brings us to 2017 And I am dubbing 2017 the year of upgrading This is where I think our dedicated team really shines They were the ones driving this upgrade timeline. So product engineers didn't need to know how to upgrade our app But they still worked with the product teams to verify that the features were still working And so this verification process and Requiring many teams to work together means that our upgrade timeline is a little slower than you might expect So in january, we upgraded to ember 2.1 and 2.2, which had been released in the fall of 2015 In february, we got to 2.5, which was released in april of 2016 In may we got to 2.7 and 2.9, which had been released in july and october of 2016 So at this point we're about six months behind And in september we got to 2.15, which was released that month And so we're all caught up And in december we moved to an ember cli app and we had to rename hundreds of components to match ember cli conventions Which we did with a code mod And we also upgraded to ember 2.16.2, which had been released a couple months earlier Around this time coffee script was deprecated in favor of es6 and java script And so we decided to do a coffee script migration using a tool called decaffeinate Which is a code mod that converts your coffee script to java script And it was written by one of our developers and is an open source tool We had coffee and donut parties and we would be hanging out in a conference room running the code mod all together So it was like a really great bonding experience for dozens of engineers helping out with the migration But now my name is on thousands of lines of code that i didn't actually write At this point we also have a team effort to manually eliminate partials Components we're becoming and now are the preference in the writer frontend community And this was an effort to move our code to match the current ember path to make upgrading easier In august of 2017 we figured out what we were going to do with our navigation structure and we split out this navigation into a separate ember app And so now even to today we have two ember apps running on the same page And one of our developers actually updated the ember inspector to support two ember apps And that was pretty painful, but we got it working and now you can choose which ember app you want to expect inspect But this is actually a must much less active repository and actually Renovate bot which updates dependencies is contributor number two In 2017 we also created something that we called sub apps They weren't in repo add-ons, but for simplicity You can think of them as in repo add-ons and we did later convert them to be in repo add-ons And we used a code mod to move all of our files around and this decomposition led us run fewer tests in ci Which made builds faster and less prone to dealing with flaky tests, which was a good thing for developer experience It also gave us better code organization because each product team Had their own sub app that they owned But it also created a lot of weird where that we had to maintain over the years And we struggled to maintain isolation between our sub apps So when the isolation wasn't perfectly enforced Uh developers could break our main branch By changing code another sub app relied on Without knowing that the sub app was going to break because ci wouldn't run the test for that other sub app And so their their pr would pass and go green, but then the main branch would fail And we used linting to help maintain isolation, but it definitely wasn't perfect Um in any case, I think people tend to underestimate how much experimentation you can do in ember We were experimenting with our dashboard navigation and with sub apps You know at this point we have two ember apps running on the same webpage And I think that ember gives you more flexibility than you might think And you'll see that as I keep explaining the next couple of years in dashboard history But I think you also have to balance that flexibility with your tolerance for weird wear In 2018 in january We created a first version of our css library that was released as an ember add-on And we had extracted common styles and components from dashboard to be used across many of our square ember apps Uh, and then we also upgraded to ember 2 dot 18 which was released that month In april dashboard got its first engine And in august we upgraded to ember 3.1 which had originally been released in april earlier that year On 2018 we also added a package called wire js And this is based on squares open source package called wire which is designed to incorporate protocol buffers and android and java We use protobufs for a lot of our services service communication And it's often easier for developers to create apis for our dashboard front end using protos But protobufs are the worst on the front end And so wire js is what we built to make it a little bit better One of our tools one of our developers built this tool to make it easy to consume and use protobufs apis in dashboard And it also let us do a little bit of like modeling without using, you know Ember model or ember data or some other structure on the front end But this is definitely a weird wear alert for you This package hasn't been open sourced and I think we'd like to find a better solution But it hasn't been top priority But other than that in 2018 We just keep building features and we never really hit sort of a cliff of like we can't keep going because of the framework or whatever else And that momentum is important because it helps our engineers trust ember as a reliable stable framework And they continue building up their fluency with the framework's patterns making them more efficient In 2019 we rewrote the dashboard home page and we added these widgets And you'll notice that the navigation looks different We ended up writing the home page as an ember add-on which is starting to modernize our dashboard even more In march we upgraded to ember 3.2 which was originally released in july of 2018 In april we got to 3.6 which was released in december of the prior year And in august we upgraded to ember 3.12 which was released that month So we were again caught up and that is an lts version Um, we also started doing more with yarn workspaces So yarn was released by facebook in 2016 and we were actually pretty early adopters in dashboard and brought it in And then yarn workspaces were released with yarn 1.0 in 2017 and we added them to dashboards shortly thereafter But we didn't start using them earnestly until 2019 because workspaces were buggy For many of the first releases of yarn Probably until about 1.12 which was released in 2018 at the end of the year And we actually ended up contributing a fix to ember cli so that it could find ember add-ons in a workspace And what we had Experimented with and discovered was that you know in repo add-ons work and you can do that But for us workspaces were a better solution We had learned with our sub apps that when you use in repo add-ons You don't really know where the boundaries are between add-ons and the app code and between individual add-ons And yarn workspaces let us keep our add-ons in the dashboard monorepo, which improves dependency management While also delineating boundaries using standard ember add-on patterns Um, and then at this point my team restaurants started moving our sub app code into a real add-on which is an important move in towards app decomposition with engines because engines wouldn't have access to sub app code or in repo add-on code At this point we also added a react running concurrently inside of ember in dashboard There was a team that needed photo editing capabilities for a feature they were building and that allows merchants to Insert their own images into marketing emails that they send And they decided they wanted to use a package called photo editor sdk which was a react app And so we ended up packaging the react app into an ember add-on So that we could use the ember asset loader to asynchronously load and execute the entire react framework and app code And we did extra work to make sure that react would be lazy loaded Only when you visit that feature's page, so you won't always be loading react And it's important to note here though that we're not actually sharing any merchant context with the react app In 2020 we upgraded to ember 3.16, which is another lts And we opened the pr in may and unfortunately It's still open because we had too many observers in ember model that broke going trying to get to ember 1.13 But even though we're behind we're feeling okay because we're on an lts And for a little background ember model is a lightweight modeling library for ember with a limited feature set And it was released as an open source project in 2013 and we started using in dashboard around that time And its last release was in 2018 and we had continued to maintain a special square branch to patch problems as we continued to encounter them But we had ended up using ember model for several several years and in 2020 it all came to a head and we encountered this crossroads Ember model was weird where and it was breaking dashboard So like we had before almost annually we asked Is this the breaking point? Is this where we decide to toss it all and rewrite it? And if we do that should we rewrite it in react? And the answer was no we decided That though the upgrade path was costly in the short term there were so many benefits and the long term that it was worth it to migrate from ember model to ember data We'd get rid of the ember model weird where and there would be thorough better documentation and more community support for using ember data And we would also get more extensive functionality for the models that we migrated We also realized that we'd be able to upgrade ember more quickly in the future and finally Rewriting in any other framework we knew would be at least an order of magnitude more difficult than the proposed migration Although we didn't know the exact difficulty The established ember path has a lot of value and so we decided to stick with it So we started an ember model to ember data migration and to give you a sense of scale We've converted over 800 models in about 500 files off of ember model And we're well on the way. We're not done yet But i'm really excited about octane features to come that we'll be able to get once we're able to upgrade past 3.12 And to be more on like a standard ember path again and ember infrastructure So we won't have to go through this kind of painful migration again In 2014 square open sourced a package called qunit bdd which stands for business driven development for testing Which we used extensively in dashboard But in 2017 square deprecated this package recommending that folks use mocha instead for bdd style tests However, we continue to use this package into 2020 and we knew that it was weird wear And so one of our developers wrote a code mod to switch from qunit bdd to more regular qunit modules And another developer wrote a code mod to remove some custom assertions that we had built into dashboards qunit in favor of qunit dum And i really like qunit dum i had used it on my other team and was excited to have it back Um And i think it's important to recognize that ember the ember open source community has a lot to offer And i'm excited that we are going to continue incorporating more of it into dashboard In 2020 we also had a push for more engines We created a generator for conveniently setting up add-ons and engines in our dashboard monorepo My first ember i wrote my first ember engine in the monorepo And i ended up writing a lot of documentation about how to do it And since then i've taught A class on how to build engines internally and we've seen an uptick in teams interested in building their own engines And we've also started a typescript conversion Um, so you may be asking why engines? We have decided that engines are the future for square dashboard because they improve development for hundreds of our engineers They give us better code organization like sub apps did And better understanding of what product teams own which parts of code Engines are a new and for us a better isolation primitive because it makes it less likely that we're going to collide with other teams Because our engines own their namespaces Uh engines also let us share code between ember apps So we can have it running in multiple places with a single source of truth Which saves time for our developers while giving our customers a better product experience Um, ultimately we hope That we with enough lazy loading of engines that the customer experience will be faster when loading dashboard because they'll only have to Load the pieces that they need when they need them And engines and their dummy apps make iteration much much quicker for developers Running the dashboard app or test locally can take anywhere from 30 to 60 seconds to do a full rebuild after making changes Ember dummy apps and tests can build rebuild in three to five seconds and this makes developers feel more productive and it just feels better Um, and in the future we're looking forward to hopefully be able to deploy end in engines individually Instead of requiring a complete deploy of the entire model with when changes are ready to go out And this will make it easier for teams to own their production code and not be blocked by other teams And here we are in 2021 and we have come a long way So what made this possible? Think number one is all of the tooling. Um, we used code mods and lints extensively And lints were especially important because they let us Um, make sure that migrate during migrations. We aren't regressing and we aren't introducing a now bad pattern Another thing that was was a lot of time Um upgrading requires attention. We had a dedicated team that was anywhere from, you know, three to eight engineers So it wasn't too big uh to maintain our app and it has gotten smaller and more focused over time And we also have an internal community of developers that are encouraged to work on these sort of platform features inside of dashboard in addition to their product work Another thing that made this possible is ember stability, you know Upgrading and doing this over the last 10 years is part of ember's philosophy And that like this is a good idea and a good path ember doesn't say start over Which is good because we've considered a square and we can't afford to start over And upgrade paths are helpful and lts versions are, you know, the backstop when we can't upgrade quickly enough And if you stick within the standard path and patterns you can leverage ember for a long time and still have room to explore And finally the open source community Um, so ember is opinionated and the patterns are widely used which make it easy to google And easy to transfer knowledge between ember apps I left after three years and ramped up to dashboard Uh at the beginning of last year faster than my manager was expecting because I was fluent in ember Um, but also I think it's important to note that like Weirdware is part of the ember ethos and it's a sanctioned enough path that so long as you periodically revisit your decisions To see if you should change them It's okay, you know ember doesn't want stepping off the path to be a full eject And but I will say that it's the weird way that makes updating updating and maintenance difficult But upgrading and reversing weirdware decisions is possible and we are proving that even today So today, I hope I have convinced you that with ember you can build for the long term With ember you can build resilient apps and with ember you can build apps that evolve We've used ember for 10 years for our main front end project at square and we have chosen to stick with it Looking ahead We want to continue decomposing our monolith into engines and this is going to require that we finish the ember model upgrade And that we move those models then into add-ons that the engines can access And also that we move global values into services for the engines We're also looking forward to upgrading to octane and good news. You don't have to get rid of jQuery to upgrade to octane Um, but we are actually already using some octane features in dashboard despite still being on 3.12 Things like angle bracket components native class native classes and decorators the on and function modifiers and splat attributes Now currently we are not able to support glimmer components and the at-track property We're going to have to continue removing deprecations to get to 4.0 We've essentially silenced a lot of deprecations instead of doing the work to remove them so to fix them. So we'll have to do that We're going to continue upgrading our tests and tags And we're going to write more typescript And yes, we're hiring


Hello everybody Andrea here, so I have been a dental professional for about 17 years, I have my own mobile dental hygiene practice, so. I want to talk to you guys about what is the cost of dental teeth cleanings, because I can ask this question, all the time. There is definitely a range so even for new patients for me, that is typically the first question people ask is how much do you charge. For a teeth cleaning and I explain it does vary and i'm going to show you guys some pictures in a moment of why. A dental professional will tell you it does vary, we need to see when person to really know. We can give you an idea, depending on certain things you tell us, and that is how long has it been since your last cleaning.  Somebody who comes more often hopefully won't have any gingivitis hopefully they won't have any periodontal disease, so those are basically. Infections inside the mouth that can happen if you don't take care of your teeth gums properly by regular teeth cleanings but having that said if it's been 10 years. We are just so happy to see you we're not going to make you feel bad if it's been 20 years if you've never had your team clean be. Before we are going to work with you hopefully work out a payment plan, so you can have your teeth cleaned and things are going to look amazing Okay, so let me share some pictures with you. How much a teeth cleaning would be and why okay so i'm going to switch the slide here, so.  They can get pretty bad sometimes, so if you're a bit squeamish I guess beware. Or you might not want to watch this I don't know it doesn't get much worse than this, but this is just kind of a little taste of it Okay, so look at these photos.  Some more work done because they have cavities they have stain a teeth cleaning won't get rid of cavities Okay, so if you have cavities that look like this. We can only do so much with the cleaning anyway, but just to kind of show you guys the difference Okay, so the next slide. If your teeth look like this this isn't so bad, but notice how there is more stain on the bottom there's tartar. or calculus, some of us call it tartar some of us call it calculus, it means the same thing plaque on the bottom Okay, so the more plaque tartar calculus stain you have. It takes us longer to clean the teeth, we need to use different instruments we're cleaning above the gum line below the gum line the gums might have a lot of bleeding so that takes us longer it depends on how difficult the case is so. What I tell my clients is I do have quite a range I let them know it could literally be 100 and and you know $80 or it could be $400 I know that's quite a range so 180 is usually the cheapest. 400 if you have extreme stuff going on i'm working hard for like the full hour I can't see we're taking off like 20 years of staying. it's going to cost you different right, but the nice thing what I like to offer my patients is if I have a patient that says. Can you do as much as you can I have $200 that's as much as I can afford right now, can you do as much as you can absolutely. So what I do is I, I will do as much as I can of what the client can see, so I would take away this you know staying first. I might not work at the teeth at the back, because I might not be able to get that far with that amount of time and that amount of money. That the patient has you know, so I kind of work on the the areas that they can see because, as a as a patient. You wouldn't be very happy with me if I clean the back teeth it cost you $200. And you said oh I thought you were going to get rid of the same here why didn't you do that it doesn't even look like I had my teeth cleaned. I might have been working hard for that full hour, but you don't care you want your stain removed, so I will do that first, so I do work with payment plans. Another photo just to show you guys, so this is a very light amount of stain. This is a child to by the way, because you can see the teeth are coming in here, but this would be easier to clean. Then this you know, so this with this amount of stain depending on how easy it is to take off might cost $100 maybe even less like it's hard to say, to be honest with you. Without seeing it inside the mouth how things look so this is going to cost less than this, this is going to cause more because there's more going on, so you guys just that makes sense. Another slide here so gingivitis and perio these are gum infection, so we don't just look at the teeth. We look at the tissues around the teeth, but notice how there's a little bit of redness here there's a lot of redness here if we see this. That usually means there's plaque and tartar stuck underneath the guns, so you might be looking at this picture and saying oh the teeth look pretty good what's the big deal that's not going to cost too much. And I might think the same thing right, but then when I look at the tissues around the teeth I go there's a big it's puffy here. It should never be puffy that usually means something's wrong there's plaque and tartar underneath. there's some redness here, so we have to clean underneath the gums as well, we don't just clean the teeth here. If we just did that your tissues would be puffy red swollen you would have gum. Infection everywhere not cool, so we also clean underneath the gums so just because things might look okay you don't have staying limited plaque there might be a lot hiding underneath the gums it depends on. If you're using mouthwash what toothpaste how often you brush the foods you're eating, so we look at a lot of things so just to quickly show you guys again. This would cost different than this, we have this we have this and then there you go so. But please keep in mind, we will never think Oh, this person's teeth are dirty you what is wrong with you. we're not going to lecture you we're not going to yell at you, I guess I can't speak for every dental professional. But I don't do that I make it a point to tell every new patient or even if there's just patients asking questions like hey Andrea. I just want to know how much do things cost, are you okay if I haven't been in for like two years or 20 years. I would love to see that is my job is to clean the teeth, I personally do the very best I can to work with your. What your budget is if you if you have insurance you don't have insurance it doesn't matter I work with what you can afford. And we go from there, so let me know you guys, if you have any questions, I hope that helps to shed some light on why some people's teeth. are easier to clean why some people's mouths are harder to clean and why it's really hard for us to give you a cost estimate so let me know. If any questions, thank you guys so much for watching click like on this video because that does help to support me, I would really appreciate it, you guys are awesome and we'll talk to you very, very soon.


Should we sally forth and continue to find out the limit of our process you got to go to the brakes man science Go till it breaks seems scary that's that's your bone to pick


Oh, one more thing I wanted to mention. We'll be talking about the brainwave entrainment of monaral beats later in the program. You'll understand what that means when we get to it. But we have some playing right now in the alpha frequency range, hoping that we'll put you in a state of calm, relaxed focus and concentration to be able to retain the information from this presentation more. OK, let's see. So making brainwaves. Brainwaves are also known as neural oscillations. Here we go. So the brain is an electrochemical organ. And that means that electricity is produced by the chemical changes in the brain at the neuron level. A neuron or a nerve cell is the basic unit of the nervous system, and that's a cell that carries electrical impulses. The dendrites, well, here we go. So the dendrites are the branches that receive chemical messages from other neurons, which are converted into impulses. And your neurons don't actually twirl around like that in your brain, so either mine might. I don't know, I don't know, but not yours. The soma refers to the central cell body. The axon is the trunk of the neuron that sends messages or impulses to other neurons. You can see that demonstrated by that little beam of light that's coming down. And the axon terminal contains the buds at the end of the axon from which chemical messages are sent. Then the synapses are the small gaps that separate neurons found between the axon of one neuron and the dendrites of another. So basically they would be linked up head to tail. Brainwaves are generated by the synchronous firing of neurons known as pyramidal neurons. So that's a special type of neuron that lives in your brain. They reside in the brain's cortex. They fire synchronously in what are known as neural ensembles. Because the neurons dendrites all point in the same direction, their synchronized activity creates an electric field that can be measured from the scalp. The instrument that does this measuring is the electroencephalogram, or the EEG. So that's a diagram of how that electrical current is generated. Brainwaves share the same characteristics that all waves do and are measured by their frequency, amplitude, and phase. These characteristics are extracted from neural recordings using time frequency analysis to determine a person's brain wave frequency. In general, EEG signals have a broad spectral content similar to pink noise, but also reveal oscillatory activity in specific frequency bands. So these are the most common brainwave bands. And there are five basic brainwave oscillation patterns that I will be focusing on today. They are gamma, beta, alpha, theta, and delta. Gamma is the brainwave frequency that is the fastest with a frequency range between 40 and 200 hertz. And these occur when different brain regions fire in harmony, such as in moments of insight. Gamma is also associated with peak concentration and high levels of cognitive functioning. Neuroscientists believe that gamma waves link information from all parts of the brain together, causing the brain to work most efficiently. So that's like a whole brain. Beta waves, associated with a frequency range of 14 to 30 hertz, and hertz again are cycles per second. These are the type of brainwaves generated by our brains when we are fully awake and alert. Our brains generate beta waves when we are thinking actively, problem solving, engaging in productive activity, or actively communicating with others. Beta waves in the higher frequency range also are associated with states of high alert, such as fear and agitation. Alpha waves, associated with frequency levels of 8 to 14 hertz, are the type of brainwave our brains produce when we become relaxed. So that's what we're aiming for right now. Generally speaking, alpha waves are produced when we're super calm, but very much still aware of what's going on around us. They can be associated with unwinding in a stress-free environment, after work, light meditating, or engaging other forms of quiet contemplation. Beta waves are produced when our brains begin to calm down to an even greater degree and are associated with states of reduced consciousness. Beta frequencies are covered by a range between 4 and 8 hertz. We produce these during light sleep or dozing, deep meditation, profound visualization, hypnosis-related states, and drowsiness. And delta waves are the type of waves produced when we are actually unconscious or asleep. Frequencies here range between 1 and 4 hertz. And in addition to deep regenerative sleep, this state is a key contributor to immune system function and a person's overall physical health. Next, we'll explore the ways that neurotransmitters contribute to brainwave states and ways that brainwave states lead to the release of certain neurotransmitters that produce physiological effects that are beneficial in learning, memory, and wellness. So there is a two-way thing going on there. Neurotransmitters are the chemical means of communication between the neurons that are diffusely distributed in the brain, and they are responsible for the creation of the brainwaves. So you can kind of think of them as the electrical current. There are hundreds of neurohormones, neuropeptides, and neuromodulators, but a few among them are the most important and well-studied. These include dopamine, serotonin, acetylcholine, Y-aminobutric acid, or GABA, and glutamate. There is a connection between different neurotransmitters and different regions of the brain, as well as different brainwave frequencies and regions of the brain. As far as we can tell, each brain center generates impulses at a specific frequency based on the predominant neurotransmitter it secretes. In other words, the brain's internal communication system is based on frequency. When we send in waves of electrical energy at, say, 10 hertz, certain cells in the lower brainstem will respond because they normally fire within that frequency range. The frontal lobes have dopamine in abundance, which creates the predominant beta waves of these lobes and is responsible for alertness. The main neurotransmitter of the parietal lobes is acetylcholine, which is responsible for the creation of alpha waves and determines the thought processing time and the speed at which the brain works. Temporal lobes abound in GABA, which produces theta waves and generates a natural analgesic, tranquilizing and generating a calming response in the mind. While the occipital lobes are serotonin rich. Serotonin is converted into melatonin by the pineal gland and creates delta waves responsible for the deep sleep stages. The prefrontal lobes are rich in glutamate, which generates the gamma rhythm.  Since these neurotransmitters are produced once a certain brain wave frequency range is reached, it is also desirable to affect what neurotransmitters are being produced by bringing a person into a specific brain wave frequency range. This process is known as brain wave entrainment. It's also known as neural entrainment or brain wave synchronization. So those are all the same things. Brain wave entrainment is any procedure that causes one's brain wave frequencies to synchronize with a periodic stimulus, which could be sound, vibration, or light, having a frequency corresponding to the intended brain state, for example, to induce a trance, sleep, relaxation, or focus. Brain wave entrainment was first identified through scientific tests in 1934, but brain wave entrainment has been happening for a long time. We'll talk about some examples of brain wave entrainment throughout history now. And we'll start by discussing the use of visual stimuli. Ancient scientists were fascinated by the phenomenon of flickering lights. Apuleus experimented in 125 AD with a flickering light produced by the rotation of a potter's wheel, finding that it could reveal a type of epilepsy. That's probably something that we're most familiar with through pop culture out of flickering lights and strobe lights, hypnotode and such. Ptolemy studied in 280, the phenomenon of the flickering generated by sunlight through the spokes of a spinning wheel. He noted that patterns and colors appeared in the eyes of the observer and that a feeling of euphoria could be experienced. Clinical reports of flicker stimulation appear as far back as the beginning of the 20th century. Pierre Genet, a French psychologist and psychotherapist, reported that by having his patients gaze into the flickering light produced by from a spinning spoke wheel in front of a kerosene lantern, they showed a reduction in their anxiety and hysteria. Not long after the discovery of the alpha brain wave by Hans Berger in 1929, researchers found that the strength of the wave could be driven beyond its natural frequency using flickering lights. This is called photic driving, which is another word for brain wave entrainment using photic or light stimulation. In the 1930s and 1940s, scientists such as W. Gray Walter and others used powerful electronic strobe lights and the new EEG equipment to alter brain wave activity, producing trance-like states of profound relaxation and vivid imagery. Next, we'll talk about auditory stimulation. Music has long been known to have evident psychological and physiological effects on humans and to be used intentionally for that purpose. We're familiar with the term photic driving for light now, so this would be known as auditory driving. Early examples of auditory driving are seen in the drumming of indigenous peoples in Africa and the Americas. The repetitive drumming used in tribal rituals is typically a rhythmic beat close to the frequency of EEG delta and lower theta waves in the 0.8 to 5.0 Hertz range. Some theorists consider the auditory driving of the theta wave to be a possible entry into an altered state of consciousness. Remember, theta waves produce calm and reduced consciousness. We produce these during light sleep or dosing, deep meditation, profound visualization, hypnosis-related states, and drowsiness. The ancient Indian system of nada yoga is a science of inner transformation through the power of sound. Nada or nad yoga is the conscious use of sound vibrations like chanting, mantra, and musical resonances to treat various spiritual and psychological conditions. Practitioners focus their mind in meditation and then use sound to access the higher states of consciousness and healing. This meditative state is again characterized by the theta frequency range. In ancient Greece, music and medicine were also closely connected. They had the same god, Apollo. The contributions of several philosophers, mathematicians, and writers, including Aristotle, Hippocrates, Homer, Plato, and Pythagoras were instrumental in developing the music-healing connection. These philosophers were convinced that music could be used therapeutically. This belief was put into practice when those suffering from manic episodes were treated with flute music and those plagued with symptoms of depression were instructed to listen to dulcimer music. Ancient Greeks were even said to treat hangovers with music, the right kind. It is also important to note that ancient Greece, we know very little about their system of musical notation, so musical elements such as tempo, rhythm, and pitch remain lost to the ages as far as these therapeutic musical numbers were concerned. Some of this ancient knowledge was put to rest until the 1700s when Diogel measured physiological responses on the effects of music. He brought live musicians to his laboratory and his patients' bedsides to conduct experiments and record his findings. And he worked in a mental hospital in Paris. This is an example of probably someone who could benefit from this bedside chamber music. This is a patient who is experiencing hysteria there. His published paper in the 1800s showed that music lowers blood pressure, increases cardiac output, decreases pulse rate, and in general assists the work of the parasympathetic system. So this tendency for the body's physiological responses to synchronize with some external stimulus is now known as the frequency following response. You may have heard other studies about how some kinds of music are beneficial for studying. By playing music pulsed at about 60 beats per minute, the frequency following response can induce alpha brainwave states. Listening to these rhythms naturally paced to our body's state of relaxation causes the breath and heartbeat to become calm and regular. The slow, large-o or adagio movements of baroque music composed by such 17th and 18th century musicians as Vivaldi and Bach follow the 60 beats per minute pattern that has the most powerful and relaxing effect on the mind. Other types of music with faster tempos can be used to induce beta brainwave states. And I do want to make the distinction here that this is talking about tempo and beats per minute, not wavelengths and cycles per second, which we have been talking about up to this point. So there are two paths to entrainment. There's the frequency following response where body rhythms and pulse follow the beats permitted of the music, and the body physiological reaction affects the brain and the brainwaves and neurotransmitters produced. In the other direction, brainwaves can entrain to hurt cycles like in the photic flickering effect, and the brain affects the body and its physiological response. I also want to mention here that this is not the same theory behind the Mozart effect, which is not based on the brainwave entrainment research I'm covering in this presentation and which has been debunked, but that's for another presentation entirely. Okay, so coming into the present, we'll talk about the field of psychoacoustics. Psychoacoustics is the scientific study of how music and sound impact the nervous system psychologically and physiologically. Simply, it is how sound impacts the mind and the body. The principles of brainwave entrainment have been incorporated into experiments with sound generated to bring people into specific brainwave states through binaural, monoral, and isochronic beats. Sound has also been combined with light pulses in audio-visual entrainment. Binaural beats were first theorized in 1839 by Heinrich Wilhelm Dove, but first scientifically tested and proven in 1973 by Dr. Gerald Oster, a medical doctor and biophysicist. With binaural beats, brainwave entrainment happens inside the brain and is caused by a physiological response. Upon hearing two tones of different frequencies sent simultaneously to the left and right ears, the brain perceives a third tone based on the mathematical difference between the two frequencies. For example, if a 200 hertz sound frequency is sent to the left ear and a 200 hertz to the right ear, the brain will process these two frequencies and perceive a new frequency at five hertz. The brain then follows along at the new frequency of five hertz, producing brainwaves at the same rate of hertz. This is another example of the frequency following response mentioned previously, which is used here to entrain brainwaves directly rather than indirectly through entraining bodily responses of breathing, pulse rate, and muscle relaxation. Monoral beats are the result of mixing two separate steady tones externally, producing nearly the same sound as that of the binaural beats. The concept behind monoral beats and monoral brainwave entrainment is the same that underlies binaural beat entrainment. Two slightly different steady tones are introduced to each speaker and the resulting sound is mixed before it reaches the ear. So the result is similar to a binaural beat, but since the produced tone is formed outside the skull, monoral beats do not require headphones to work, whereas binaural beats do.  It is very effective because the tone is not heard at all during the pauses, although accompanying music may provide a background. The contrast between on and off is very high, inducing a strong neural response. In comparison with the binaural beats, where you hear a continuous sound that fluctuates in volume, you hear a sound at distinct time intervals with isochronic beats. Some people compare it to the sound of a helicopter to give you that reference. So there we go again, internally five hertz. So combining the effects of light and sound entrainment, audio-visual entrainment uses flashes of light and pulses of tones to guide the brain into various states of brainwave activity. Audio-visual entrainment devices are often termed light and sound machines or mind machines. Besides entrainment to external stimuli, there are other methods of changing one's brainwave frequencies. Meditation. One safe, simple way to alter one's own brainwaves in both the short term and the long term is through meditation. Meditation has roots in the contemplative practices of nearly every major religion. It can be broadly thought of as the cultivation of basic human qualities, such as a more stable and clear mind, emotional balance, a sense of caring mindfulness, and love and compassion. Studies on mindfulness meditation have shown an increase in the prevalence of alpha wave activity, not only during meditation, but also during other daily activities. Alpha waves are likely responsible for creativity and relaxation. Because alpha waves are so internally focused, they also make it easier to recognize bodily sensations such as pain or pleasure. This would explain why mindfulness meditation helps people conquer depression, anxiety, and chronic pain. By increasing the presence of these calm, self-reflective brainwaves, meditation allows people to think more clearly and soothe their own negative emotions. Another study published in 2014 in Scientific American talks about modern technologies used to offer insight into the effects of meditation. In the year 2000, the 14th Dalai Lama brought new focus to the study of connections between science and Buddhism by launching the subdiscipline of contemplative neuroscience. He did this by inviting scientists to study the brain activity of expert Buddhist meditators, defined as having more than 10,000 hours of practice. For nearly 15 years, more than 100 monastics and lay practitioners of Buddhism and a large number of beginning meditators have participated in scientific experiments at the University of Wisconsin-Madison and at least 19 other universities. Advances in neuroimaging and other technologies enabled scientists to gain insight into what happens in the brain during three major forms of Buddhist meditation. Focused attention, mindfulness, and compassion and loving-kindness. Focused attention meditation aims to tame and center the mind in the present moment while developing the capacity to remain vigilant to distractions. A brain-scanning study at Emory University has pinpointed several distinct brain areas that become involved as attention shifts. Mindfulness or open monitoring meditation tries to cultivate a less emotionally reactive awareness to emotions, thoughts, and sensations occurring in the present moment to prevent them from spiraling out of control. In mindfulness, the meditator remains attentive moment by moment to any experience without focusing on anything specific. Expert meditators have diminished activity in anxiety-related areas, such as the insular cortex and the amygdala. The meditation practice known in Buddhist tradition as compassion and loving-kindness fosters an altruistic perspective towards others. Brain regions that fire up when putting oneself in the place of another, the temporal parietal junction, for instance, show it an increase in activity. Before the benefits of meditation were widely known in Western society, people were already experiencing the benefits of these practices via the relaxation response. The term relaxation response was coined by Dr. Herbert Benson, professor, author, cardiologist, and founder of Harvard's Mind Body Medical Institute. The response is defined as your personal ability to encourage your body to release chemicals and brain signals that make your muscles and organs slow down and increase blood flow to the brain. Dr. Benson's book basically took his studies on the benefits of transcendental meditation and demystified it for a Western audience. The relaxation response is a helpful way to turn off fight-or-flight response and bring the body back to pre-stress levels. Dr. Benson describes the relaxation response as a physical state of deep relaxation which engages the other parts of our nervous system, the parasympathetic nervous system. Research has shown that regular use of the relaxation response can help any health problem that is caused or exacerbated by chronic stress. Exercise is also very important in brainwave maintenance. Exercise alters brain chemistry by increasing dopamine, norepinephrine, and serotonin. These chemicals are produced during the alpha and theta states. Tai Chi and yoga exercise studies demonstrate numerous benefits, increased relaxation, including decreased anxiety, a trend for increased EEG activity in the theta and alpha ranges, and reductions in depression, anxiety, and sleep disturbances. Although exercise is considered a form of stress, it seems that what makes exercise-induced stress different from stress due to negative life events is that, in contrast to psychological or bad stress, physical or good stress is associated with increased inactivation of the stress hormone cortisol into cortisone, which is in its inert form, and increased brain levels of the fatty acid AEA, brain-derived neurotrophic factor, and serotonin. In particular, it seems that aerobic exercise modulates hormone, neurotrophin, and neurotransmitter levels. Yoga and aerobic exercises bring about a rise in the levels of dopamine, GABA, and acetylcholine levels, while anaerobic exercises build up the serotonin levels in the brain. Exercise is also shown to play an important role in the learning process, one of the desirable targets for brainwave entrainment. The first positive effect of exercise is an increased oxygen flow to the bloodstream. Aerobic exercise has been shown to pump more blood throughout the body, including the brain. More blood means more oxygen, which increases capillary health and the growth and plasticity of the frontal lobes. A second physical benefit comes from the release of protein IGF-1, which triggers the release of brain-derived neurotrophic factor, BDNF, which in turn stimulates neural growth and learning, and this has been called Miracle Grow for the Brain, so you don't have to put Miracle Grow on your brain. Studies have shown that exercise enhances student learning and positively affects emotional and physical well-being. Research also shows that we continue to grow new neurons throughout our lives. Therefore, a third and perhaps most important benefit of exercise is neurogenesis. One of the places in the brain neurogenesis has been found is in the hippocampus, which is involved in the storage, consolidation, and retrieval of information. Research has also shown that exercise plays a role in the generation of new cells in this structure. And biofeedback. In the 1940s, psychologists and other researchers began to investigate artificial ways of giving people feedback about otherwise hard to monitor states. For example, they developed machines that picked up electrical signals from muscles and converted these signals to lights, visible signals that might reflect the degree to which a person was unknowingly tensing up his or her muscles. It was a short step from here to see if people could learn to alter these signals and thus change their own physical or mental states in desirable ways. Researchers eventually created the term biofeedback to refer to procedures that allow people to monitor their physical and or mental states and train themselves to change these states. Neurofeedback is the term for biofeedback that gives people feedback about their own brainwaves. Neurofeedback devices collect information via EEG, galvanic skin response, and heart pulse and breath rate monitors. These devices measure stress and relaxation parameters and then play back the signals to the user so they can use the signals as a beacon to guide and steer themselves into a relaxed state. These have increasingly incorporated the use of video feedback and gamification. There has also been a growing consumer market for these devices. Check out Amazon when you get home. Two other elements that are not necessarily brainwave entrainment methods, but which are foundational to the functioning of the brain are diet and sleep. The food we eat directly affects the efficiency of the neurotransmitters in our brains. Nearly all of the brain's neurotransmitters are composed of amino acids. We obtain amino acids from the food we eat, so it makes sense that what we eat affects the amount and efficiency of these brain chemicals. The amino acid tryptophen, synthesized from carbohydrates, is used to produce serotonin, a neurotransmitter that creates feelings of well-being and calmness. Tyrosine, an amino acid found in proteins, is used to make dopamine, a natural stimulant. Amino acids are also used to protect DNA and brain cell components from damage. The quality of the food we are eating also matters. Recent findings have also confirmed the benefits of highly unsaturated fats, commonly referred to as omega-3 fatty acids. These fatty acids, found in cold water fish, flax seeds, eggs, and certain meats, are crucial for hormonal balance and the immune system, both of which are essential for a healthy brain. Studies in animals have shown that diets without omega-3 fatty acids lead to learning and motor problems and may affect systems that use dopamine and serotonin in the frontal cortex. And sleep. Quality sleep and getting enough of it at the right times is essential. Without sleep, you can't form or maintain the pathways in your brain that let you learn and create new memories and it's harder to concentrate and respond quickly. Sleep is important to a number of brain functions, including how neurons communicate with each other.  There are periods during the sleep cycle when the brain is as active as when you are awake in solving a problem, which may be exactly what the brain is doing. Some researchers call this the nocturnal aha moments that we may wake up from a dream and have the answer synthesis of something that we've been working on.  Given that sleep is a time when brain cells replenish themselves and when connections made during the day are strengthened, sleep deprivation can have a major negative effect on brain functioning. So coming back to the libraries, we've been all around through time and space and science and we're right back where we started here. Today we've talked about brainwaves and different methods to help get brainwaves to a desired frequency range and that different brainwave ranges are helpful for different tasks. So this is a diagram that shows of different brainwave frequencies, their ranges and the general characteristics. So this can be a really helpful chart to figure out how to use the different brainwave and treatment ranges to focus on different programs. Brain researcher, Ned Herman, believes that knowledge of brainwave states enhances a person's ability to make use of the specialized characteristics of those states. These include being mentally productive across a wide range of activities such as being intensely focused, relaxed, creative and in restful sleep. So this opens the door for us to offer library programming in a way that leverages these brainwave frequencies or library classes, events, that leverage these frequencies and practice. And we're already offering many programs that do this at our branches. I know that many of us already offer meditation, yoga, Tai Chi, musical programming, study classes, all these different types of things. So one option that we have to use this information that I shared today is to pair these programs with information sessions about brainwaves that explains the benefits of those particular activities. I did this last summer when bringing the Muse of Baroque group to my library to play and presenting a brainwave entrainment talk focused on the effects of Baroque music and learning afterwards. Making the program and the presentation directly relevant to each other led to a very engaged audience and hopefully one that was entrained to relaxed learning. Another option would be to have a guest speaker come talk about the different biofeedback consumer technologies that are currently available. This talk could also include discussion on the plethora of brainwave entrainment videos available online through YouTube and other sites. So having an expert to come in to kind of help people along to find out what is of good quality and what has sound science involved is very important because this is a very popular field increasingly so nowadays. So there is lots of varying information out there. There are lots of books out about the brain as well and having a nonfiction book group highlighting these topics is also an option. We can also utilize brainwave entrainment to make an environment during programs that supports the kind of activities our patrons are doing. If we want to relax with a coloring club we could be playing alpha brainwave entrainment music in the background. If we want to boost creativity at an art program we could attune to those brainwaves that are focused in the creativity range. What about hosting classes for training in new skills from computers to knitting with the learning entrainment music? How about we use it for after school crowd control to calm people's senses? I've not looked into the ethics of these but... We can also use these to market and promote our programs that appeal to the specific types of desired outcomes. So if we want to market programs for study programs, study skills, learning then we can promote the kinds of brainwave entrainment that go along with those programs as well as relaxation and wellness. Those are just some ideas that I have in my brain but we all have brains that are generating brainwaves and great ideas right now so I'm also curious to find out about what you all take back with you and the places that you go with this information. Thank you very much. Oh yeah and if anyone has any questions I am happy to answer questions. That is a very good point about this to practice everything with caution and I do know that some of these ranges have been used to completely make people lose all control of their bodies. Yeah I actually had an electronics music professor when I was in college who he and his buddies thought it would be like really great to go into their music hall with the equipment that would be able to play these frequencies because they thought it was a big joke and they had to crawl out of the room so yes please take all of this with caution maybe stay out of those lower ranges work towards optimizing your relaxation, your meditation skills and your focus. Oh let's see so this sound is actually from a file from YouTube and I first got into the topic of binaural beats when I was working for the Brisbane Library down in San Mateo County and our system had a box set by a psychoacoustic engineer named Tom Kenyon called the ultimate brain so it had multiple different disks and different brain wave frequency ranges along with a guide book and I had not been familiar with this technology previous to that but as mentioned in my intro it was one of the first things that I found that could actually help me fall asleep and stay asleep so I in my time in research and finding out more about this and doing this presentation at other libraries I've had other people come up to me to let me know that they have also experienced the benefits of using binaural wave entrainment. Oh yeah white noise I don't know too much about that as far as entrainment is concerned but that does give kind of like a broader range of frequencies in the sonic envelope so I think that can be soothing to people who want to kind of disperse their focus from the individual sounds and the environment to be kind of like a broader range of sound and I do know that white noise machines are also used to block sound and speech especially in environments requiring privacy like therapists or psychologist offices so that's probably another reason why people are able to use that for sleep. Okay, oh yes please. Yeah that's, so ASMR is recorded with the use of binaural microphones so it's actually more accurate to how you hear than using a single microphone and splitting that sample. And I do know that there has been a push to remove ASMR videos from sites like YouTube for some reason I think it has to do with its connection to the belief that it is a factor of sex work which is really not accurate. Yeah that's also what I, yeah. But if, I don't know how familiar everyone here is with ASMR but it's a type of recording where people respond physically to soft touch or very close sound like this so there are lots of videos you can find online with people talking very close and very silently about this and it's really important to some people that don't have the ability to have somebody close in their life like that. So that's a little bit of a, yeah. So that's another area of research to go into and I really appreciate all of your questions because like I could go on for days about this stuff. I was only able to like include some of the copious research I unearthed but I will be sure to send around links or information with the different sources that I use so that you can follow up on those different scientific studies. Thank you.