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Today, I would like to share with you my thoughts about how ideas and methods from physics can be used to help us broaden our understanding of the brain. There are two broad ideas. One idea is that we are embedded in the physical world and therefore our sensors have to obey physical principles because we interact with photons, we collect sound waves and other signals from the environment. And today I will tell you some broad ideas about why I think hyperbolic geometry is applicable, is relevant for many aspects of organization in the nervous system and also how symmetry breaking can be used to categorize biological complexity. There is a viewpoint that one of the distinguishing features of biological systems is that they are quote-unquote complex, they are composed of many heterogeneous elements and so maybe that's one of the distinguishing parts from physics where we have many body systems but the units are homogeneous. So I will describe how some ideas about phase transitions can be applied to understand and categorize biological complexity. I am at the Salk, I am in the computational neurobiology laboratory but half of my talk will be today actually about plants, tomatoes, strawberries, blueberries and other plants and the reason I became interested in plants is because there is a long-standing idea in neuroscience that in order to understand the brain we cannot do it in isolation but coupled to the natural environment. And for the sense which is our faction which is one of the least understood senses, the sense of smell, the natural world is to a large extent is defined by plants. So that's how I started with physics and we will talk about a little bit of chemistry and we will see how hyperbolic coordinates can help us categorize the sense of smell. So a general idea, so in the smell but also in visual system, so imagine that our world, our visual, our goal is to figure out what's happening, what's out there, so that's how we use our senses. And there is a certain hierarchy within the natural scenes, you can imagine that there are hidden causes such as three bears or other object trees. And then they all reflect light, they reflect sound waves and they result in rather detailed measurements that are spread out in the world. And the job of our nervous system is to reconstruct this. We receive detailed measurements corresponding to say, intensities of light across our sensors. And the job of our, of the brain is to figure out what are the hidden causes that led to those observations. So one of the recurrent themes for today's discussion is that both natural scenes and the nervous system have opposing matching hierarchical organization. When it comes to the sense of smell, when preparing for the stock, I read this article that was actually written by Alexander Graham Bell more than a hundred years ago where he lamented the fact that in the sound and we have a theory of light because we have a way of measuring light and we have a theory of sound because we can measure sound waves. But how do we measure distances between orders? So he said it's very obvious that we have many very different kinds of smells from violets to roses and others, but until you can measure the likenesses and differences you have no sense of order. So that's one of the problems that we would like to address. It's still an unresolved problem and I will describe our approach, our ways towards that. So if we think about human order perception, especially we were discussing yesterday in other circumstances, if you're buying wine, right? They describe to you it's rosy with, I'm not a big wine drinker, but you know there are a lot of qualitative terms. And sometimes it says, where does this come from? So you know we will characterize this smell in terms of whether it's natural or chemical, it's rosy, does it smell like a mushroom, and that just begs for something more quantitative. So the goal is to find what is the dimensionality of oral factory perception. And the goal is to ultimately produce a set of coordinates such that you can say my preferred wine coordinates are 3.5, 2.4, and 7, and that's my preferred wine. Somebody else can prefer a different wine, but you know just like in the science of color I can say I want to paint my walls pink, but I can also go to a store and say give me the color with these RGB coordinates. In the color it's a little simpler because we only have three receptors. In the alfaction we have hundreds of receptors, but that still does not exclude the possibility that this space is low dimensional and this is what we found. So in thinking about this problem it was interesting that I learned this apparently that the way we classify orders is very similar to how species were classified before Darwin. So they would classify, apparently there were these games played in Europe for how to classify species based on the set of overlapping descriptors and in ways that are analogous to how we describe orders. So they would say what is the shape of the hoof, what is the shape of the paddle, all kinds of qualitative descriptors. So apparently Darwin knew that there is a mathematical mapping from a set of descriptors such as here to a hierarchical network and that's what the mathematical fact he used to reconstruct the tree. So the idea is that if I have a, I can represent a data structure as a kind of a category within a category in terms of overlapping circles, but I can also equivalently represent it as a tree. So the largest, so for each circle here the X and Y coordinates become X and Y coordinates here, but the Z coordinate is the size of the circle. So the largest category gets assigned the highest Z coordinate and the smallest circle gets assigned the lowest Z coordinate. So one can see that the all-encompassing category is the root of the tree and then it branches to a smaller circle. So there is a mathematical mapping from one set of descriptors to a tree. So that's one of the suggestions for, these are some of the facts that I used to propose that perhaps the hyperbolic coordinates might be relevant for the categorizing of orders. The idea is that the way we use smell is, you know, I want to figure out whether something is good for me to eat or not. So it's in a very correlative way. So the idea is that the molecules are produced in correlated manner by hierarchical biochemical pathway within a plant and so our observation of individual order molecules will be like leaves in that tree. So I roughly organized the talk into three parts. I will talk about hierarchical organization of natural orders. So this is an example of a study of natural seen statistics. And we'll talk about neural representations and going inside the nervous system and there I will switch modalities to talk about vision which is one of the best-studied visual systems in neuroscience. And the third part will be application of symmetry breaking to understand cell types that are encoded to one dimension. So moving on was the natural orders. As I mentioned, the structure of the factory space is very complicated and hard to understand. So if we think about a strawberry and for insects, for example, its plants are a very important source of natural orders. One of our collaborations is on bees and insects and it turns out that the bee can navigate to a flower but then it has to make a very important decision whether to land on a flower or not. And it will land or not depending on sometimes she needs pollen, sometimes she needs nectar. And when the flower is pollinated it changes its smell. And the bee is very dangerous for it to land on the flower because once it lands the spider can hide under the flower and if there is a spider that's the end for the bee. So she uses alfaction to make important decisions. So in any given plant or a flower there is a complicated mixture of molecules approximately. So people have measured 80 molecules per sample and we took advantage of datasets that are publicly available from food industry. So they're interested in creating a perfect strawberry, a perfect blueberry, a perfect tomato. As you know that when the plant is, when you grow your own strawberry it smells nice but then when we go to, when I go to supermarket then sometimes they don't even smell at all. So and smell is a big component of how we perceive taste. The two senses are very coupled. So when people study this is a dataset from this paper and so they look at different genetic varieties of strawberries. So there are approximately 80 different genetic varieties of strawberries in this dataset. And each of these genetic varieties is measured in terms of approximately 80 different monomolecules. So here is the concentration of this molecule from this sample or of the same molecule across a different sample and so on. So my way of thinking about it, of how are we going to define distances between molecules? Previous attempts were to define distance between molecules based on the chemical structure. But it turns out that molecules that have similar chemical structure can smell differently and so on. So that hasn't been particularly successful and in fact one of the leading models of the olfactory system is that it's randomly organized such that they have a set of receptors and each of the receptors has more or less random selectivity for the odorants that are out there. And one can use ideas from compressed sensing and other techniques to figure out from these sensors the composition of orders. So our approach was to define statistically distance between molecules, meaning that I will define distance between molecules. If they are more correlated across these samples, then they will get assigned a smaller distance. The idea is that this is how I use an olfaction in every day.  So if it smells bad, then maybe there is, I learned by prior experience that maybe there is a certain bacteria that is poisonous and that maybe I shouldn't eat the sandwich. So we use the olfaction in a very correlative way. So that's how the, so this is, the motivation was to define distance between molecules based on statistics. If they are often co-occurring in the natural environment, they get assigned smaller distances in our approach. So now imagine that I have 80 molecules and I give you distances between them. So the next question is on what surface I can embed these molecules? So suppose I give you distances between major cities on Earth and if they from London to Brisbane, from London to New York, from London to Beijing. So at some point we will figure out that the distances are not consistent with the flat geometry. So in our case the distance matrix will be between say monomolecular orders and we will try to figure out what are these distances with what geometry they're consistent with. So and the spherical geometry, so for each order we measure distances with other orders and we figure out whether it's consistent for example with spherical geometry or not. So the mathematical approach is that we get molecules, so in this case six but in reality it's about 80 and we measure pairwise distances between all molecules. Then we generate points randomly from different candidate geometries and we measure distances between them and then we are going to compare them and to do that we will use a topological analysis that was developed by Vladimir Ritskov and colleagues and basically it says give me if I'm given this matrix I'm going to threshold it at for example the given level and if the correlation is higher than my threshold then I will assign a link between nodes 3 and 5 and so on and then I will measure a set of cycles or holes in this network this is my joke with Swiss cheese but in this network and we can measure these cycles and holes in many dimensions so for those who work with topological analysis it will be the number of the Betty curves in one, two and three dimensions so in one dimensions a circle then kind of a prism and also in three dimensions. So I view this topological analysis as the first step in performing nonlinear dimensionality reduction because we only have 80 molecules we do not have that many samples to sample the surface so we want to find kind of roughly in ways that are invariant towards nonlinearities in measurement what is the how whether this sampling of a surface is consistent with the data so in this particular case the the data points will be in black triangles and the measure the variability from the model geometry will be in these colored yellow. Is it guaranteed that you can always find a consistent? No it's not guaranteed so it's a way of I would say ruling out geometry so we can so I will show you that some geometries we can allow it and some we can say they're consistent but that doesn't exclude that if I have more data maybe that geometry will also be ruled out yes sit again. Have you measured the distance? Yes so the distance matrix it's a key question thank you for your question so the distance is a correlation in Pearson correlation coefficient between two orders like p1 and p2 here across different samples so going back here so this is the distance between say p103 all and p103 1 you measure you take a correlation between these values and one can try different measures for example one can take a logarithm prior to taking correlation coefficient and we did it in both ways and the results didn't change so there is some flexibility with respect to how to define a distance is that is that okay so it's a correlation across samples the distance is a correlation between two molecules across samples and in principle it just for the strawberry but this is sort of a segment of the natural world and then we will try to broaden it to bigger categories so we tried starting with strawberry data we tried three candidate geometry so of constant curvature so spherical euclidean and hyperbolic and the hyperbolic is our favorite because it provides a continuous approximation to a hierarchical tree like networks so what we found was that the hyperbolic geometry matched the strawberry data but not the and we could rule out spherical and euclidean uniformly distributed points so this is an example of analysis that I showed on the previous slide the triangles are data from strawberry and this is Betty numbers one two and three and then if we look at euclidean the first we fit parameters of the model such as dimensionality to to match the first Betty number but then use these fitted parameters to see how they would match Betty numbers two and three and it's are clearly not consistent with the data same thing for the spherical model and for hyperbolic it was consistent so that doesn't exclude the possibility that um you know with additional measurement maybe the curvature will not be constant and we optimize the curvature here so in this model we optimize the curvature and also the geometry was that to match the data we had to take points near the edge of the space I will I will show you visualization of the space so it turns out that there are more data sets the student who did this work I asked him to take a look at the strawberry and he came back and said I have more data sets I found data set of samples of mouse urine blueberry and tomatoes so this is like many samples here so each time each data set is approximately 80 different monomolecular orders and it turns out that the hyperbolic geometry in three dimensions and was points lying near the edge of the space describe all four data set and the optimized curvature value was also similar across the data set so now I'm going to visualize so we found that we want to find the points in the 3D hyperbolic space so instead of two-dimensional tree we are going to go to a three-dimensional tree and many of you know but so the hyperbolic space is difficult to visualize so if I if this is in like a 2D hyperboloid but I can squeeze it into a Poincaré disc and the distance between the two points kind of goes has to be evaluated by going closer to the center now this in 3D instead of a Poincaré disc we will talk about Poincaré sphere and we then use the modified the multi-dimensional scaling with the hyperbolic metric to find to put points actual automolecules into that Poincaré sphere and this is visualization of the two molecules two example molecules before I started that didn't tell me anything but just maybe maybe you know more about the chemistry but this if your brain turns out it's some molecule that is characteristic of berries from Finland so these are all kind of characteristics melt from berries and just to remind you that when I said we rolled out spherical geometry it's true so this is a representation of the hyperbolic space squeezed into Poincaré sphere and the reason is that to emphasize this fact I'm showing you the the geodesic between the two points that goes closer to the center so in my you know the way I think about it this is a continuous approximation to a tree so in order to compute the distance we have to go closer to the center of the tree and then come back up is that okay so and we can visualize this sphere three 3D oh we fit them based on the Betty curves so whether whatever fits so higher dimensions didn't fit the Betty curves could be rolled out by the Betty curve analysis so as I mentioned it's like an idea you know in general to perform nonlinear dimensionality reduction is difficult so we can use topological analysis as the first clue about what is the dimensionality of the space and what is the metric and once we determine dimensionality and the metric we can embed points in that space yes so beta one is the number of cycles cycles in one dimension so it was four points it's like a square so and then beta two is like a pyramid so the number of cycles in two dimensions and beta three the number of three-dimensional cycles in the network and what happens is that if you go back to that network that approach so in reality so as I said that you have to threshold this metric at some level and for a given threshold you will get some number of cycles in one two and three dimensions and then you can adjust this threshold and what you get is a Betty curve because the number of cycles and I will be it's shown here in the I guess I'm not showing Betty curves in the beginning when the threshold is very high the network is not connected so there are no cycles and then you add more edges to the network so cycles appear and then at some point the network becomes fully connected and again there are no cycles so generally as a function of the threshold or the edge density it increases the number of cycles and then decreases and then if you integrate that curve that's the Betty number one and then same thing for Betty number two is the number of cycles in two dimensions it grows and then it drops to zero and then three grows and drops to zero and then we integrate this curve to have one number and in doing this it becomes independent of the setting of the threshold and that's one of the advantages of this method because it's invariant over its one-to-one non-linear transformations of the distance matrix what's the difference well in our case it's x squared plus y squared plus d squared minus t squared equals to a constant with a corresponding constraint so it's a point career ball model but I thought that it's a version well in the Minkowski spacetime is curved I thought that Minkowski spacetime was curved really yeah so it is curved so the I mean it is curved I have a curvature and everything so so you know I don't know what you mean by flat or curved but it has a curvature it's not a euclidean metric Minkowski space is not a euclidean metric yes well maybe we can discuss it later but because I think I can map it to both both spaces yeah so this is technically it's a point career ball model so it has one minus and some pluses and we can I'm not going to argue you know whether it's three pluses and one minus or vice versa but it is curved and we have a curvature of seven so so this space so far that I showed to you had data points that were purely based on statistics but now we actually have ratings of how much people like these strawberries and these orders so now the color of these points represent how much people like the order so in one can see even though we didn't say anything about the nervous system there is a continuous mapping here such that there is a region of space in in this case where that people prefer best so this is one of the so the color here is the normalized pleasantness value and we can define this red axis that goes from most pleasant orders to the least pleasant orders and this is sort of the prediction of how we can predict the pleasantness of new orders kind of separating the orders into some sets to find the axis and others to test predictions and one can have significant predictive power for new monomolecular orders and this was actually one of the open problems in alfaction of how to predict how the order will smell based on its physical chemical properties and yes there was a question here yes good yeah thank you that's right so you can we did it actually for both individual molecules and for orders so the in this graph each point is a molecule and now there are two ways to can to evaluate either we assign pleasantness to the order by how much it was correlated was the reported pleasantness when part of the mixture so it's kind of correlation between with the reported pleasantness in the mixture and it's and it's correlated and its concentration or you can instead of these points you can plot mixtures that correspond to different orders so if I have for you know a mixture will have 80 components and for each 80 components I have 80 points and they take a weighted combination of these orders to put points into into the space so in the paper we have a sphere that where each point is an order and another sphere where each point is a sample okay so yeah yes so intensity yes so for now the intensity we haven't systematically studied the intensity the right so yes yes so there is intensity in axis I would say it's the next question one answer is that to some extent our depending on one can to some extent our within within a certain range our perception is invariant towards intensity and then of course there are violations of this so we didn't specifically look at intensity in this case because it's was normalized correlation there are yes that's right the intensity matters but also you know the order identity because I can be at different distances from the order source and we would like to know what it is and then a separate question of how far it is so because the space is low dimensional three-dimensional actually most of the points here lie near the boundary of the space we can predict we can look at other axes so in this case molecular boiling point how easy this molecule evaporates so that's a green axis or how acid was the sample and it's again the correlation between the order concentration and acidity in the sample and one can see one that there is these axes predict these values for new orders but more interestingly now because the space is curved you can if you know the coordinates along these to other axes you can predict coordinates in the pleasantness axis so there is a way of predicting how pleasant the order is based on its other properties so the close this is close to the summary of the first part and I would like to summarize it with the fact that we find that there are hyperbolic coordinates are consistent with the orders implying a hierarchical organization for orders and the all the orders are kind of the leaves in this tree so the idea is that they are volatile and therefore they do not react too much with each other and so they do not lead to other new molecules and so they are all equally kind of distant from the hierarchy of chemical reactions and so how they are perceived in the brain so there are the alfactory system is one of the oldest sensory systems in some way it's the simplest and it has what from a machine learning perspective would be a three-layer neural network and some of you know that there is a theorems from going back to Kalmagorov that we can use this type of architecture to encode any function and and perhaps this is what the alfactory system is doing because we have receptors they have some sensitivity to the molecules so that's receptors are like hidden layer and then the neural responses in the in the cortex would combine responses from from the receptors or from the glomeruli to reconstruct what were the smells that were present so the theorem by Kalmagorov says that you can approximate any function so if it smells like this maybe it means a predator and run away if it smells like the different way maybe it's food and you can hide it for the winter so one can encode any function but of course the size of this layer can be very large so that's the trick and it turns out that each receptor requires a separate gene and the family of alfactory receptors is the largest gene family one of the largest gene families in our body so if I want to increase the accuracy of the alfactory systems every cell in my body has to carry an extra gene so it's of course a very expensive solution our other senses we are not particularly we don't rely on alfaction in everyday life so there are so the information capacity well we do but we rely on vision much more or that's quality so anyway one can quantify the information capacity for the alfactory systems but in vision and other senses there is a different solution many of you know there is a revolution in machine learning where they say that the accuracy of the number of the expressive power that we can achieve using these architectures can be exponentially increased if we instead of relying on three layers we will stack these layers and that's sort of the solution that has been found by newer sensory systems including vision and auditory system so in in my second in the middle part of my talk I will describe briefly our progress in understanding what happens across these hierarchical transformation stages in vision it is a it's a very old problem and right now one of the challenges for example in machine learning is we can train this deep network that it will predict many things based given the data but we would like to understand what is it how does it do it the focus is on explainability and it's perhaps instructive that that's the problem that we have been facing in systems neuroscience and if you've been working on it for about 50 years because we have a brain it's a deep neural network and we would like to know what exactly it does so in the visual system there's a hierarchy of areas the first processing stage is primary visual cortex in the back of the brain and this was analyzed or the first breakthrough was from Hubel and Wiesel who got their Nobel Prize by demonstrating the ignorance in v1 are sensitive to edges to orientations within the different scenes so decomposing the visual scene into little edges so here's an example of the neuron from the primary visual cortex from their paper such that if the edges horizontal there are no responses and if the edges 45 degrees the neuron if this is the voltage across time across the neurons membrane and one can see there are these they're called spikes in the voltage stereotypic events in the voltage trace across the membrane so when the edge for that neuron is at 45 degrees it produces lots of responses and then when the edge is horizontal for that neuron it doesn't and therefore each place and for each orientation there is a corresponding edge in the primary visual cortex so from the primary visual cortex signals go to secondary visual cortex and it's still not known what does this does and then they go through a series of edges and at the end in the inferior temporal cortex we find different kinds of neurons when it's the animal sees the hand the neuron responds with lots of spikes now this is the number of spikes per second if you simplify hand to a method the response is reduced for that neuron if it shows a face the response is further reduced but then if you show it a hand at 90 degrees the response comes back so now how do we wire signals from v1 which represent edges of individual digits in ways that are invariant towards the position of the hand rotation of the hand size of the hand and not get confused with a metron or a hand so it's a very complicated problem but what gives me hope is that and I spend a lot of effort analyzing the signals that there is a enormous amount of convergence even from this area v1 to the area v4 so visual area 4 approximately each neuron in v4 collects ultimately signals from 1 6 of the v1 surface so it's a huge amount of convergence and if it was without any patterns or any order I think all the hope of selectivity would be lost so I spend a lot of effort understanding how signals propagate within the visual system it's very technical work so I will just summarize briefly so think about that we have layers as in deep network from say retina or thalamus which is another relay nucleus to primary visual cortex secondary and v4 but here comes a trick that each unit here that in the machine learning is just a single threshold like unit in reality is a systematic network where a signal is a process across layers in specific ways and how to think about this well we try to find a model that an element of a circuit and the methods are described here that can capture some of this complexity but at the same time can be manageable and from the fitting perspective so the way we did it is kind of fit summarize this unit as a threshold linear unit with respect to an argument of the logistic function that depends on multiple input components from one matrix and then we're going to diagonalize that matrix so it's semi convex so this this unit can be fit in a convex way but also we can then find the eigenvectors and relevant modes for each of the units so each of the units has multiple features so I'm glad I would be happy to go more into detail but in the interest of time I will just summarize the results so a signal so if you are faced with this you are looking at the koala bear here signals go from v1 to v2 and then they split into v4 an area empty with middle temporal area sometimes known as v5 and in v1 roughly things code edges such as the edge here in v2 neuron's recent work shows that they represent textures and they called second order edges so what's a second order edge is like here this is an edge that has similar orientation similar luminance on both sides but the texture is different and then in area v4 neurons are sensitive to curvature and color I think so this is a broad description and in area mt is like pattern motion so I will just summarize what we found for v2 fitting these rather complicated semi-dip networks with each unit that is modeled taking to account what we know about neurobiology and what we found for example here is one example analysis for area v2 and instead of being sensitive to one edge as in v1 it now collects information from a number of edges and positive edges that excite the neuron are in blue but it also sensitive to edges that are orthogonal that are in red that suppress the neural response and that's important because what does it mean to have an edge it means to have the edge of the correct orientation and absence of an edge of the wrong orientation this is one example v2 neuron this is another example so they will be sensitive to different types of textures and then it's only the first part of the model and then the second part of the model is how the signals are pulled so this element is actually very small and the model says well it's going to be tiled across the visual space over some range that we will determine by fitting and then we this is an experiment kind of the fitting mask that we construct from the data and for most of the neurons it's uniform so the corresponding neuron would be recording a patch of texture but for some neurons this the mask is biphase going between negative values here to positive and such neurons a will be able to encode the second order edges and b they're pulling masks are very similar to what Hubel and Wiesel described for v1 neurons including luminance but here we find the masks that v2 neurons apply to v1 output so there is a kind of a hierarchical approximate repeating computation going on from different stages of cortical processing and this is another summarizing another maybe six years of work in area v4 we find that the neurons are tuned to curvature so here example relevant features for v4 neurons but there is a range each neuron has we could find at least two features and usually they had a similar curvature so range range from so there's a one two three four five six neurons each neuron is quantified in terms of the two features and some neurons are more curved and some neurons are less curved and those that are turns out that were more curved were less positioned invariant one can understand this as if I want to quote the contour I need to be more precise about its position if the curvature is tight and linking back to the hyperbolic coordinates in the first part of the talk there is actually all the evidence that our visual perception is also hyperbolic and one of the ongoing efforts is to put these features as elements of a hyperbolic system and so I have maybe seven minutes or is it seven minutes yeah okay so the phase transitions and but characterizing biological complexity so what I described was hierarchical organization natural world how it can be described as hyperbolic coordinates hierarchical visual representations and then this is for neurons that are sensitive different features in the environment but there's another type of hierarchy that some neurons there's a set of neurons that are devoted to encoding the same feature in the environment the same signal but at different thresholds the reason is that suppose that we need to do a kind of an analog to digital conversion in the brain meaning that if this is the feature contrast it can be say temperature or any other environmental variable of interest it can be for example the degree to which the edge matches the the visual the natural scene matches the pattern that we are seeking and it fluctuates in time and now I have a neuron that is supposed to report to me the value of this coordinate but neuron to the first approximation is a threshold like thing and if if I just have one neuron encoding one feature the most I will be able to convey one bit of information so I will not have full value about the underlying signal one bit per kind of unit of measurement but if I have many receptors then and they are all very precise then I can stack them according to the distribution of input signals then in this way from the pattern of their responses they can reconstruct the the underlying analog variable so in the limit the optimal distribution of thresholds should match the distribution of input signals and that's result that was derived by Simon Laughlin but now there is a trick well the point is that each neuron doesn't have a perfect threshold in order for it to have a very small there is some variability in either the signal the input signal there is noise or variability in the threshold so it turns out that the optimal solution if each of these threshold like devices is has a finite uncertainty associated with this threshold then it's no longer like this but it's actually kind of clumped into groups and the number of groups in exact position of the groups depends on metabolic constraints it depends on the amount of noise and ultimately if the noise is too big then it's optimal to have all neurons be with one threshold and just average their responses this is a qualitative picture and now I can show you the quantitative analysis for two neurons and white I'll explain why it leads to cell type specialization so the idea is suppose I have I simplified this problem very much I have an analog variable and I'm going to encode it with two thresholds and they each threshold has a certain amount of noise that is plotted on this axis and what's plotted on this axis is the threshold difference between neurons so I'm asking is it what is better is it better to set the thresholds equal or separate so for example if there are two workers and they're unreliable sometimes I have to assign to them to do the same task and average the results and when they get more reliable you can assign them different tasks in order to get the overall job done so this is the same idea so we compute how much information jointly the two neurons provide about the underlying analog signal as a function of threshold difference and when the noise is large the information is maximized when the threshold difference is zero so that's the redundant solution you just average the results then this information surface has a bifurcation so this single maximum splits into two maxima and the moment the noise falls below the critical point and one can see that it actually matches the landow theory of mean field theory of phase transitions we can identify all parameters noise is equivalent to temperature information is equivalent instead of maximizing information you minimize the free energy what's this there's a symmetry breaking is the exchange symmetry between neurons because initially in this situation I have two identical neurons to identical detectors with the same amount of noise and I have to randomly assign one of them go towards a threshold that is closer to the mean and one will go further from the mean so in biology as you might know there's these events called gene duplication so you have identical gene and then they're duplicated and one is mutated and usually one has higher sensitivity receptor and the low sensitivity receptor so that's the idea we can actually test these ideas in the retina which is the the sheet that is in our eye and it turns out that there are neurons that are sensing light increases these are on cells the yellow cell here and light decreases which are off neurons turns out that the off neurons have smaller amount of noise and they split into subpopulations and it was very puzzling why for each of the type of on type there is a pair of off cell types and now we can explain this actually with no adjustable parameters because we can place the position of this critical point if I know the kind of the average threshold position then we can make a prediction for this critical point and it separates the values for the off cells from the on cells explaining why the off cell types split into sub types the everyday illustration of these ideas is that you might notice that we prefer to read black letters on white paper and not vice versa so it turns out we have higher acuity in the off channel than in the on channel so it's much easier to have been constructed a black paper and a little bit of white ink but we have a lower resolution and so this is an illustration for why in the off channel we have smaller noise and higher acuity and there are more cell types and more neurons in the off channel there is more I can say about this because it turns out that these two cell types have slightly different noises and in this case this picture of the phase transitions gets converted from a second order phase transition to a first order phase transition because this surface tilts now and the analog of the magnetic field is the difference in noises between these two neurons so the the one that has less noise goes towards the mean of the distribution and the one that has larger noise goes towards further from the mean of the distribution so as a summary the work I presented we had three parts the LFACTION was done in collaboration with brand smiths who studies BLFACTION and was interested in natural statistics of orders and the work was done by Yuan Chengzhou a student at UCSD and Ilan Zhang did information theoretic calculation for random coding in the factory system the the visual work in v4 was done in collaboration with laboratory of John Reynolds and analysis Jude Mitchell, Anirvandhanyi and Minchenko are former postdocs who now have their independent faculty positions Ryan Rovenkamp is a student who is now a postdoc in my lab and he did analysis of v2 neurons that we did using the data set that was made publicly available online from Jake Gallant's laboratory and actually there was a lot of this work under was based on a large background work on computational methods and how to fit these deep networks that have multiple components at each unit to neural data so some of the work that we are there it is ongoing is analysis of this recurrent circuit I mentioned that each kind of computing unit in the cortex has a stereotypic architecture and we are interested in those recurrent networks we think a lot and there's a I think a match between this is like infotaxis solutions that we were inspired by Masimo's Virgasola's work together with British Rhyman matching the infotaxis solutions to how worms search for food and also thinking about eye movements and actually within cells with yeast in collaboration with Vicky Lundland and the Salk Institute I didn't talk at all about auditory perception but prediction is very important in addition because we have to think about in auditory perception and in the music it's the prediction is very important part of it and the retinal work that I mentioned was done in collaboration with Stephen Bacos's laboratory at Stanford so this is my qualitative summary slide of why I think the hyperbolic geometry is applicable to neuroscience and the reason is the one word summary is speed because these tree-like networks allow for fastest communication between different parts such that the system can respond best to internal and external perturbations and of course this is true both for for different kinds of animals both for plants and for us so in final I would like to thank Terry who is a great mentor at the Salk Institute and my group who joins me in Vishenu thank you for your attention


Hi viewers, I have an announcement for you. C-prestorming, which is a reliable test series for UPSC prylums, is offered by Arshaan Kauraiya's Academy. Already three batches are running successfully and the fourth batch, which is having its first test on 21st of December, is open for enrolment. See aspirants, do make use of this test series. It will be really helpful for clearing your prylums in an easy manner. With this happy notes, let's start our Hindu newspaper analysis brought to you by Shankaraiya's Academy for the day 17th of December 2022. Displayed here are the list of news articles that we have chosen for today's discussion. See today we have and eight articles are from different topics. Now without wasting much time, let's get into the first news article discussion. Now have a look at this news article. This news article is about a notice issued by the National Green Tribunal to the Tamil Nadu state government. Why the notice was issued? Because the state government plans to construct a monument of the Merina beach in Chennai. The monument is supposed to be in the shape of a pen and it is planned to owner the former chief minister of Tamil Nadu Dr. Kannanithi. Here the problem is not with regards to the monument but where it is planned to be constructed. That is the problem. It is proposed to be located around 360 meters into the bay of Bengal from the Merina beach. So it is planned in a Merain ecosystem. That is why environmentalists are concerned over it which led to the filing of a public interest litigation. The moment I sit Merain ecosystem is involved you should have understood that the coastal regulation zone notification comes into play. See the proposed monument falls under the CRRZ1A then CRRZ2 and CRRZ4A areas. So it is worried that the monument might affect the Merain ecosystem. Therefore now the NGT has sought the state's response to the PIL. In this regard let us see about NGT from preliminary perspective. See it was established in the year 2010 as a statutory body and it was established under the National Green Tribunal Act 2010. It functions as a specialized judicial body that is equipped with expertise solely for the purpose of adjudicating environmental cases in the country. That is why it is dealing the case with respect to the Merain ecosystem. See for fulfilling this purpose the tribunal is empowered to deal with the subjects in the legislations mentioned in the Schedule 1 of the NGT Act. I had given what are all the legislation see just go through it this is very much important because in prilams they might give these legislations and ask which among the following are present or not present like that questions may be asked. Okay now coming back see there are several reasons behind its establishment which forms its objective. First is for the effective and expeditious disposal of cases relating to environmental protection and conservation of forest and other natural resources. Secondly to enforce an illegal right relating to environment. Then it is also empowered to grant relief and compensation for damages to persons and property and for any other matter connected with it. So to carry out these objectives know it has presence in five zones namely the north, central, east, south and west. But the principal bench is situated in the north zone which is headquartered in Delhi. Then it enjoys several powers like it is not bound by the procedure laid down under the code of civil procedure 1908 but it is guided by principles of natural justice. Also its orders know are binding and it has the power to review its own decisions. If this fails the decision can be challenged before the supreme code within 90 days. Other than this know the tribunal is mandated to dispose applications or appeals finally within 6 months of filing of the sale. Then what about its composition? See it is headed by the chairperson who sits in the principal bench and it also has two sets of members who are judicial and expert members. Then each set can have at least 10 but not more than 20 members. So that's all regarding this news article. See through this news article you had known why this case was filed and then we had known about this NGT and its role in dealing with environmental cases. So with these key points in mind let's move on to the next news article discussion. Now have a look at this snippet article. It mentions that a marathon was organized by the Indian army to celebrate Vijay Duvas. See what is a Vijay Duvas? Vijay in Hindi means victory and Duvas means day. So a Vijay Duvas is celebrated to remember the bravery and sacrifices of the Indian defence forces especially in a war. We normally hear about Kargil Vijay Duvas which is celebrated in July. Then this Vijay Duvas is for which war? It is to commemorate the victory of India over Pakistan in the 1971 war. See here the war was fought between the allied forces of India and Bangladesh on one side and Pakistan on the other. Now let us quickly recap what led to the war. See it all began in the 1970 due to the internal crisis of Pakistan. Don't forget here that at that time Bangladesh was a part of Pakistan. That is from 1947 to 1971. This Bangladesh was part of Pakistan and was called as East Pakistan. But the people of Bangladesh region recented the domination of western Pakistan and the imposition of the Urdu language on them. It was an unfair treatment to the Bengali culture and language of the Bangladesh region. So they started protesting and demanded fair representation in administration and fair share in political power. This popular struggle against western Pakistani domination was led by Sheikh Mujibur Rahman. Remember he had an additional demand of autonomy for the eastern Bangladesh region that is liberation of Bangladesh. In between all this elections happened in the then Pakistan. Awami League won the elections in eastern Pakistan which was led by Sheikh Mujib. Through this the Awami League secured a majority in the proposed constituent assembly for the whole of Pakistan. But the government dominated by the western Pakistani leadership refused this scenario and took three actions. One is it refused to convene the assembly. Second it arrested Sheikh Mujib. Third is the Operation Searchlight. Pakistani army was used in this operation by which the mass movement of the Bengali people was suppressed. You know that at that time Pakistan was a military rule and the presidency of general Yahya Khan. As a result of this operation thousands were killed. Even today Operation Searchlight reminds one of the most horrific examples of mass atrocities and brutal killings in recent history. This operation led to a large scale migration of Bangladeshis into India. See around 80 lakh people migrated. So it created a huge refugee problem for India. And India intervened. It supported the demand of independence by the people of eastern Pakistan and held them financially and militarily. This resulted in a war between India and Pakistan in December 1971. After a long war on 16th December 1971 the Pakistani forces having 93,000 troops surrendered unconditionally. They surrendered to the Allied forces of India and Bangladesh in Dhaka. The end of the war resulted in the freedom of Bangladesh. That is why this war is famously known as the Bangladesh Liberation War. Since at that time Indira Gandhi was a prime minister. Newspapers reported like this. Yahya yields to Indra ends war. So India was bound to celebrate this historic military victory over Pakistan. For that every year on 16th December Vijay Duvaz is celebrated. Its objective was to commemorate this glorious occasion. Also to pay homage to our gallant soldiers who made the ultimate sacrifice in the service of the nation. So that's all regarding this news article discussion. See we took just the snippet article and discussed about the Bangladesh Liberation War in a brief manner. And then we saw why this Vijay Duvaz is celebrated. So this is the way we take a small article and cover which is very much relevant for our UPS examination. With these key points in mind now let's move on to the next news article discussion. Have a look at this news article. The news article says that the Supreme Court set aside a direction given by the Allahabad Eye Court. The case in question here regarding theft of electricity by a person. He was awarded a total jail term of 18 years. The Allahabad High Court also held the sentence to protect the convicts personal liberty. The Supreme Court set aside the direction of Allahabad High Court. While pronouncing the judgment our Chief Justice of India said that the right to personal liberty is a precious and inalienable right recognized by the Constitution. This is about the news article. In this context now let us go through article 21 of the Constitution which grants right to life and personal liberty. See article 21 as we all know deals with the right to protection of life and personal liberty. The article says that no person shall be deprived of his life or personal liberty except according to procedure established by law. This article mainly restricts the state which is nothing but the government here from encroaching upon a country's citizens right to personal liberty. There is one exception that is provided in this article itself. It says that the state can encroach upon the citizens right to personal liberty by procedure established by law. That is if the parliament makes a law that restricts the citizens right to liberty then the government can encroach on our rights. So this is about this article 21. See this is a very important article. Various judicial and constitutional experts are of the opinion that if there is a competent judiciary then by a wider interpretation of this article all other fundamental rights can be derived from it. This is why in the Unikrishnan's case our Supreme Court termed this article as the heart of the fundamental rights. Now let us see the evolution of article 21 through various Supreme Court judgments. As I already said from the plain reading of article 21 we can interpret that if the parliament makes a law that restricts the citizens right to liberty then the government can encroach on our rights. But let us say for example if the parliament tomorrow makes a law that says that every citizen in India must wake up at 4 a.m. every day and do Surya Namaskar. Then our executive that is our government will implement it. Although this law encroaches upon the right to personal liberty and prevents our right to sleep till 11 a.m. we cannot oppose it. This is because the law was made by a competent parliament. This would be the case if article 21 is taken literally. So this provision of article 21 was always controversial. So obviously there were various cases regarding this. Now let us see some important cases in this regard. The first important case is the AK Gopalan was a state of Madras case that occurred in 1950. In this case our Supreme Court made a narrow interpretation of article 21. In this case our Supreme Court said if a competent legislature makes a law providing that a person may be deprived of his liberty in certain circumstances then the law is valid. The validity of such a law cannot be questioned in the court of law. That is how arbitrary unreasonable or unjust that law is if such a law is passed by a competent legislature its validity cannot be questioned in the court of law. Through this judgement the legislature held an upper hand over the judiciary. See this opinion prevailed from 1950 to 1978. In 1978 the famous Menaka Gandhi was a student of India case arrived. In this case our Supreme Court interpreted article 21 quite literally. The court said even though article 21 has word procedure established by law it inherently means due process of law. After this interpretation by the Supreme Court the advantage that legislature held over the judiciary came down. Now the judiciary and parliament were placed on the same footing. Now if the legislature makes an arbitrary unfair or unreasonable law that is taking away our personal liberty its validity can be questioned in the court of law. Even though such a law in question is passed by a competent legislature ok. Here you have to know that the British follow procedure established by law whereas if you take USA they follow due process of the law. See the Supreme Court re-hydrated the same opinion in the Francis Croyle Mullen vs Union Territory of Delhi 1981 case. In this case the Supreme Court said that under article 21 no one shall be deprived of his life or personal liberty except by procedure established by law. But this procedure must be reasonable, fair and just and not arbitrary, whimsical or fanciful ok. So through this judgment also the Supreme Court placed a restriction on the power of the legislature. The next major Supreme Court judgment regarding article 21 is the Unni Krishnan was a state of Andhra Pradesh that occurred in 1993. It is one of the important judgments that expanded the scope of article 21. See in the judgment the Supreme Court said right to life under article 21 actually means the right to live a meaningful, complete and dignified life. So to live a dignified life the court said the following rights are required. The rights include the right to go abroad, right to shelter, right against solitary confinement, right against custodial death, right of every child to a full development and right to pollution free water and air. So this is why at the start of the discussion I said if there is only article 21 and there are no fundamental rights a good judiciary can interpret it literally and provide all the fundamental rights from it. There are some other Supreme Court judgments also regarding article 21 which we can cover in the future discussion. This discussion regarding article 21 was useful. See we had taken various judgment to say that article 21 is very much important. In your preliminary perspective if you take knowing what is article 21 and what are all covered in article 21 that will be more than enough. But when you take it means perspective is article 21 the heart of fundamental rights then you can utilize these points to enhance your answer. You can make really your answer look unique and worthful. So with these key points in mind let's move on to the next news article discussion. Look at this editorial article. This editorial article talks about the recently concluded UNSC special briefing on global counter terrorism approach. See the briefing was convened by India in New York. The briefing highlighted the hurdles to better counter terrorism cooperation and ways to address it. So in this backdrop let us understand some of the important points that is mentioned in the news article. Also we will have some basic understanding about UNSC. Before that the syllabus relevant to this news article is highlighted here for your reference. You can just go through it. See now before getting into the context of the article have this basic understanding. The Security Council was established by the UN Charter in the year 1945. And it is one of the six principal organs of the United Nations. Its primary responsibility is to work to maintain international peace and security. See the council knows headquartered at New York and that is why the briefing was held in New York. Now if you have a doubt about why India convened the briefing. It is because India is the president of UNSC that is United Nations Security Council for the current month that is for December 2022. Yes the UNSC is composed of 15 members in which 5 will be permanent members and 10 will be non-permanent members. The 5 permanent members include China, France, Russian Federation, United Kingdom and the United States. Whereas the 10 non-permanent members are elected for two year term by the General Assembly. These 10 non-permanent seats are distributed on a regional basis. See India has served 7 times in the UN Security Council as a non-permanent member. And in January 2021 India entered the UNSC for the 8th time. So this is all about the membership of the UNSC that you have to know. Now remember the presidency of UNSC rotates among the 15 member states of the council monthly. The head of the country's delegation is known as the president of UNSC. The president coordinates actions of the council, decides policy, disputes and sometimes functions as a diplomat or intermediary between conflicting groups. See each member of the Security Council has one vote. So if a decision has to be made in UNSC, 9 members among the 15 member states have to vote positively. Among those 9 members, 5 permanent members of the council have to vote concurrently. That means a no vote from any one of the 5 permanent members of the council will block the passage of the resolution. So apart from reaching an agreement through mediation or dispatching a UN mission to settle the dispute, the Security Council also oversees the work of UN peace operations through periodic reports from the secretary general and council sessions. See the UNSC can even impose sanctions in response to a threat to international peace and security. So in that line note the UNSC convened a special briefing on the global counter-terrorism approach. See this UN global counter-terrorism strategy is a unique global instrument. Its purpose is to enhance national, regional and international efforts to counter terrorism. And it was adopted by consensus 15 years ago that was in 2006. This is the first time in which all UN member states agreed to a common strategy and operational approach for fighting terrorism. This move of UNSC since a clear message that all forms and manifestations of terrorism are unacceptable. So while briefing on the global counter-terrorism approach, our external affairs minister listed 4 hurdles for better counter-terrorism cooperation. Let me list out one by one for you. First one is state support for financing terror. Then multilateral mechanisms that are opaque and agenda driven. And the third one is the double standards and politicization of counter-terrorism according to where terror groups belong. And the next frontier here he was mentioning about the use of emerging technologies such as drones and virtual currency by terrorists. See note all these points all are important and the article also mentions that the sanction regimes launched after 9 by 11 are in chaos. There are many instances where the strength of sanction regimes is checked. For example while easing Taliban's path to power in Kabul the UNSC's permanent members especially the US and the UK tested the flexibility of the sanction regimes.  And the third such instance is when the P5 nations refused to come together to accept India's 1996 proposal for a comprehensive convention on international terrorism. See the briefing by India is therefore working to put words into action while the rest of the world test the strength of sanction regime. See India even convened a UN counter-terrorism committee meeting the No Money for Terror Conference and an Interpol Conference also. So to conclude the article says that the government should keep on focusing on giving a new strength to the global agenda and counter-terrorism architecture. See India should highlight the necessity for international cooperation on the matter and it should persuade all nations to contribute resources to the fight against terrorism. So that's all regarding this news article. See in this news article we had covered regarding UNSC also holistically and we also made a point to discuss what was briefed in the global counter-terrorism approach by our external affairs minister. See when the hurdles that we had mentioned are removed no the fight against terrorism or we can say the counter-terrorism approach can be implemented effectively. So in brief we can say that that the state support for financing terror should be stopped then multilateral mechanisms that are opaque and agenda driven then the double standards and politicization of countering terrorism then terrorists using emerging technologies such as drones and virtual currency should all be restricted then only the counter-terrorism approach can be efficient. So these key points in mind now let's move on to the next news article discussion. Take a look at this article it talks about a rice festival which was organized in the district of Vainat that is in the state of Kerala. See the rice festival was organized with a motto of promoting climate resilient rice varieties and this was done by a Kerala based organization called Thanan and this organization planted nearly 300 climate resilient varieties of traditional rice on 1.5 acres of land. So this is the crux of the news article given here and in this discussion we will learn about the rice crop and the conditions required for its cultivation. See a variety of food and non-food crops are grown in different parts of our country and it is depending upon the variations in soil, climate and cultivation practices. Major crops grown in India are rice, wheat, millets, pulses, tea, coffee then you can also go in for sugarcane, oil seeds, cotton and jute etc. Now let's specifically see about rice cultivation in India. As we all know rice is the staple food crop of a majority of the people in our country. It is a cariff crop which requires high temperature generally about 25 degree centigrade and high humidity with rainfall above 100 cm. Here I said cariff crop am I right? What does it mean? Cariff crop means the crops which are grown between June to November. Now coming to the regions of rice cultivation in India. See rice is grown in the plains of North and North Eastern India then even in the coastal areas in the deltaic regions. Development of dense network of canal irrigation and tubules have made it possible to grow rice in areas of less rainfall. For example you take Punjab, Haryana, even western Uttar Pradesh and parts of Rajasthan. In these places and all rice has been grown because of irrigation ok. So from this we can see that rice is grown all around our country. So now the next question is who are the leading rice producing states of India? As of 2020 to 2021 the top 3 rice producing states of India are West Bengal, Uttar Pradesh and Punjab. See around 36% of India's total rice production is from these 3 states alone. For example if you take West Bengal it contributed 30.62% of the total rice produced in India. Then Uttar Pradesh nearly 12.81% while Punjab accounted for 9.96%. Now let's see a few points about the article given today. See the festival which the article reports about is aiming to sensitize people by showing the significance of conserving traditional crops. See they have the ability to withstand harsh climatic conditions. And these traditional crops have wider adaptability and resilience suited for the particular climate in which it is cultivated for longer periods. So by conserving these traditional crops we can reduce the risk of changes in environmental conditions. Not only this we can stop crop failures then we can reduce market fluctuations and attacks of the pests and diseases. So these are all the advantages of preserving traditional crops. So with this we have come to the end of this discussion. See we quickly revised about rice crop then we moved on to see what is the importance of traditional crop. When you just revise traditional crop it is important for preliminary perspective. But when you read about the importance or significance of a traditional crop you can utilize it when your mains answer is based on this hybrid versus traditional crop. Always know to take an article in both prylums as well as mains perspective. So these key points in mind now let's move on to the next news article discussion. Take a look at this news article. This news article talks about wheat acreage. See according to the news the wheat acreage has increased 3% so far in the ongoing rainy season. So in this news article discussion let us quickly go through wheat and the conditions necessary for its growth. See wheat is the second most important cereal crop in India after rice. It is primarily a crop of temperate zone but it is a highly adaptable and it can be grown beyond even the 60 degree north altitude as well as in temperate and frigid regions of the far north. See it can also be cultivated in tropical and subtropical zones also. Wheat is able to withstand extreme cold and snowfall and begin growing once springtime warm weather arrives. So from the shore to 3300 meters above sea level it can be grown. So in short we can say that the best wheat is grown in regions that benefit from cool damp conditions for the majority of the growing season succeeded by dry warm conditions to allow the grain to ripen. Hence its cultivation in India is done during winter that is in Rabi season. This Rabi crop requires a cool growing season and a bright sunshine at the time of fry benning. See it is requiring 50 to 75 cm of annual rainfall evenly distributed over the growing season. About 85% of the total area under this crop is concentrated in north and central regions of the country. That is in the Indo-Gangetic plain then the Malwa Plateau and Himalayas up to 2700 meter altitude. Being a Rabi crop it is mostly grown under irrigated conditions but it is a rain fit crop in Himalayan highlands and parts of Malwa Plateau in Madhya Pradesh. And if you note about 14% of the total crop area in the country is under wheat cultivation. When you talk about the leading wheat producing states Uttar Pradesh, Madhya Pradesh, Punjab, Haryana and Rajasthan stands at the top. See the yield level of wheat is very high in Punjab and Haryana whereas in Uttar Pradesh, Rajasthan and Bihar they have moderate yields. See the states like Madhya Pradesh, Himachal Pradesh and Jammu and Kashmir grows wheat under rain fit conditions that is why they are having low yield. So that is all regarding wheat you have to know. This is very much related to your preliminary perspective. With this information you can attempt any prelims based questions. So with these key points in mind now let's move on to the next news article discussion. Take a look at this article. It talks about the issue of linking Aadhar with Otar ID. The issue was brought up in the parliament by two opposition MPs responding to the question. The issue was brought up in the parliament by two opposition MPs. Responding to the question, law minister of India said that Aadhar linking with the Otar ID is not mandatory. The minister also informed the Rajasabha that more than 54 crores of the nearly 95 crore total Otars have opted to link their Aadhar details with Otar ID. So this is the crux of the news article given here. In this context now let's learn about Aadhar in a very detailed manner. Before that the syllabus relevant to this news article is given here for your reference. Kindly go through it. Now let's start our discussion. Firstly let us start with the origin of Aadhar. See developed countries and even developing countries like China have databases of their citizen while also providing for each adult individual citizen of the country a unique identification number. Such a unique identification number assigned to a citizen would be a proof of his or her identity for a variety of purposes. This is with respect to global scenario. Now coming to India, presently there are different means of establishing identity in India. Such as you can take electoral identity card, income tax that is PAN card, then passport, ration card, driving license, birth and education certificates etc etc. However none of the systems are equipped to handle a population figure that exceeds more than 100 crores in India. So this is where Aadhar becomes important and this is the exact reason why Aadhar was introduced. See according to the government no centralized database of the citizen of the country with a set of unique identification number has several potential benefits to its citizen. Because it will improve the efficiency of administration. So this is all about the need for Aadhar in India. Now let's see how Aadhar was introduced in India. To undertake the mission of providing unique 12 digit number to the persons who are residing in India, unique identification authority of India was established in the year 2009. See it was established after a notification by the Planning Commission. Nandan Nilakini the co-founder of Infosys was appointed by the then government to head the project. See he is the same person who is now heading the development of open network for digital commerce which is abbreviated as ONDC. ONDC is being developed by the Government of India to open the digital marketplace in India. Here note that ONDC tries to break the monopoly of foreign companies acting as intermediaries in the digital marketplace. If successful it will bring a huge change in how digital marketplaces operate in India. Now coming back to our Aadhar. See what we have seen till now is the need and how Aadhar was introduced in India. Now let's see the technical details of Aadhar. See Aadhar is a 12 digit individual identification number issued by the unique identification authority of India. This is on behalf of the Government of India. This number will serve as a proof of identity and address anywhere in India. That is any individual irrespective of age, gender who is a resident in India and satisfy the verification process laid down by the unique identification authority of India can enrol for Aadhar. Here you must note two things. Firstly to enrol for Aadhar he or she need not be a citizen of India. Being resident in India is alone enough for enrolment. Here a resident is a person who has resided in India for 182 days in the last one year preceding the date of application for enrolment of Aadhar. So in any case Aadhar number cannot be a proof of citizenship or domicile. Secondly any individual irrespective of age and gender meaning even children right from their birth can be enrol for Aadhar. But for children below 5 years no biometrics will be captured. Later between the years 5 and 15 no the UID of children that is the unique identification of the children have to be updated with their biometrics of 10 fingers iris and facial photograph. And for this alerts will also be sent to the registered mobile number of the parent. See I have said that Aadhar had been implemented through a notification by the central government in the year 2009. But this changed in the year 2016 to empower the system of Aadhar in India. So parliament gave statutory backing in the form of Aadhar that is targeted delivery of financial and other subsidies, benefits and services act. So now the system of Aadhar governance in India has statutory backing. So this is all about the technical details of Aadhar that you have to know. Now coming back to the issue discussed in the article. The issue is that according to a judgement of the supreme court Aadhar can be used to identify welfare scheme recipients. See through this judgement supreme court has allowed government to exclude those beneficiaries of the welfare schemes who don't have Aadhar card. This judgement makes us question whether Aadhar is necessary for obtaining other identity cards in India. The answer for this question is no. So you have some understanding now right? With this now let's see the issue of voter ID linkage with the Aadhar card. Election commission of India has recently started the process of linking voter ID with Aadhar card. This has raised concerns about whether government can exclude voter IDs which are not even linked with Aadhar. This is why the opposition MPs no raised the question. And as we have seen already law minister has said that voter ID linkage with Aadhar card is purely a voluntary exercise. With this we have come to the end of the discussion. See through this discussion we saw about the origin and need for Aadhar in India. Then we also saw about whether Aadhar is necessary for receiving welfare measures from the government. And finally we ended our discussion by seeing the recent issue of linking Aadhar with the voter ID. See it is purely voluntary and not mandatory. So with these key points in mind now let's move on to the next news article discussion. Have a look at this news article. This news article reports that in Kerala a petition sought a CBI investigation into an issue. Whether Kerala High Court dismissed this petition. So can anyone seek CBI investigation? Let us find out now. See CBI that is Central Bureau of Investigation as its name suggests is a premier investigative agency of India. It functions with a dual responsibility. One to investigate previous cases and second to provide leadership and direction to the police force across the country. Especially in fighting corruption. See fighting corruption was one of the basic objectives with which the agency was set up. Here you should know that originally the organization was created as the special police establishment. After that the organization has grown so much. So we will see its growth and timeline now. See it was set up as SPE in 1941. That is as a special police establishment with a pure mandate to investigate cases of bribery and corruption. But its jurisdiction was limited to the transactions with which the then war and supply department of government of India was concerned. In this time the special police establishment functioned under a DIG in the then department of war. Later in 1942 its mandate was extended to handle cases of corruption on railways also. But to further extend its jurisdiction an act was passed in the year 1946 called the Delhi Special Police Establishment Act. This act brought in many crucial changes to the special police establishment or SPE. Firstly the SPE's name was changed to Delhi Special Police Establishment that is the SPE. And as I already said it extended the SPE's jurisdiction to union territories. This is as per section 2 of the act. This means the Delhi Special Police Establishment can investigate offenses in the union territories also. But the same jurisdiction can also be extended to other areas by the central government. It can be extended to railway areas and states. So this is provided by section 5 clause 1 of the act. But for that no one condition is to be satisfied as per section 6. See the condition is acquiring the concern of the concerned state government. Another major change was SPE's superintendence was transferred to the home department. Then its functions were enlarged to cover all departments of the government of India. Then another major development happened in the year 1948. This is when a post of Inspector General of Police of the Special Police Establishment was created and the organisation was placed under his or her charge. In 1953 an enforcement wing was added to the SPE's establishment. So from 1953 to 1963 cases under different laws were entrusted to the SPE's establishment. Thereby it was authorized to investigate offenses under 91 different sections of the Indian Penal Code and 16 other central acts. But in the year 1963 there was need for a central police agency at disposal of the central government which could investigate many other cases other than bribery and corruption. So this led to the setting up of Central Bureau of Investigation by a resolution in 1963. See it was mandated to have many divisions namely investigation and anti-corruption division, technical division, research division, crime records and statistics division, legal and general division then even administrative division. Here the investigation and anti-corruption division is nothing but the Delhi Special Police Establishment. But with time many other divisions were added to the organisation. So currently the divisions are anti-corruption division, economic offenses division, special crimes division, directorate of prosecution, administration division, then policy and coordination division, lastly the central forensic science laboratory. So we can see that in the last 75 years the organisation has evolved from an anti-corruption agency to a multi-faceted, multi-disciplinary central police law enforcement agency. Here know that CBI derives its power to investigate from the Delhi Special Police Establishment Act only. But what cases can they investigate as per section 3 of the Act? They are authorized to investigate only those cases which are notified by the central government from time to time. But with time now the CBI has grown to handle cases of conventional crimes such as murder, kidnapping, terrorist crime etc etc. And also economic offenses, banking frauds and crimes with international linkages can also be handled by them. Apart from this even the Supreme Court and High Courts entrust cases for the investigation to the CBI based on petitions filed by agreed parties. So from all these it is clear that the Supreme Court and High Court have the power to entrust cases to the CBI. Other than this know it also acts as the nodal agency for enhancing interstate and international cooperation in law enforcement. Also here you have to note that the director of CBI as Inspector General of Police of Delhi Special Police Establishment is responsible for the administration of the organisation. Currently CBI is functioning under Department of Ministry of Personnel, Pension and Public Grievances. So that's all regarding CBI you have to know. See we had known the entire timeline of the evolution of CBI along with that itself we saw the functions or the roles or the powers that CBI has and this much is enough for your examination perspective. So with these key points in mind now let's move on to the next part of the news article discussion which is a preliminary practice question discussion. See today we have five questions in which three I will be discussing and two will be a quiz question for you. Now let's start with the first question. It is regarding the National Green Tribunal. See here three statements are given and you are asked to find the incorrect statement. So let me start with the first statement. It is a statutory body. Yes that statement is correct because we saw that this NGT or the National Green Tribunal was established in the year 2010 under the National Green Tribunal Act. Am I right? So it is a statutory body. Now look at the second statement. It has the power to grant relief in the form of compensation and damages to affected persons. Yes this statement is correct. They can grant compensation. And now look at the third statement. It is chaired by the Chief Justice of India. See this statement is incorrect because the qualification to be a chairperson is a former or incumbent judge of the Supreme Court or Chief Justice of High Court. The chairperson is appointed by the central government in consultation with the Chief Justice of India. See during discussion we just saw that it is headed by the chairperson but the qualification we did not see. Am I right? That is also covered in this question. Now what is the answer for this question? Since it is demanding for incorrect statements, your answer here will be option B, three only. Now look at the second question. It is regarding the CBI discussion. Here you are asked to find the correct statement. Here four options are given. Let me start with the first option. See option A is incorrect. CBI derives its power to investigate from the Delhi Special Police Establishment Act 1946. So it is incorrect. Now look at option B. It is also incorrect. See as per section 2 of the Delhi Special Police Establishment Act, it can swore to take up investigation of offenses notified in section 3 only in the union territories. Taking up investigation by CBI in the boundaries of a state requires prior concern of that state as per section 6 of the Act. Then the central government can authorize CBI to investigate such a crime in a state but only with the concern of the concerned state government. See the Supreme Court and high courts however can order CBI to investigate such a crime anywhere in the country without the concern of the state. See be clear with this. They can take sumoto cases in union territories but if in case of state they must have the concern of the state government. Now look at option C. It is correct because it does not say only the Central Vigilance Commission enjoys superintendence over the CBI. The superintendence of CBI related to investigation of offenses under the Prevention of Corruption Act 1988 lies with the Central Vigilance Commission and in other matters with the department of personal and training in the ministry of personal pension and grievances. So to conclude, the Central Vigilance Commission enjoys the superintendence of CBI. Now look at option D. It is only partially correct. See CBI is the Interpol of India. So CBI acts as an interface between the law enforcement agencies of India and other countries to ensure such cooperation. It facilitates exchange and sharing of information by these agencies. It also published the red notices of the fugitive criminals wanted in India. But it does not deal with their extradition. See the ministry of external affairs is the nodal agency for extradition of fugitives. CBI Interpol can help the law enforcement agencies in raising or locating the fugitive. So that is why this option is incorrect. Now finally what is the answer? Yes it is option C. Now look at the third question. See it is regarding the Bangladesh Liberation War of 1971. While covering the Vijay Devas we also covered about this Bangladesh Liberation War. Am I right? So now look at the first statement. It was a war between Bangladesh, India and Pakistan. Yes right. Because Bangladesh and India was on one side and Pakistan was on the other side. So this statement is correct. Now let us look at the second statement. Indira Gandhi was the Prime Minister of India during the war. Yes this statement is also correct. Even I displayed a news article right saying that Yahya yields to Indira ends war. So now what is the answer for this question? Since the question is demanding for correct statements. Both statements are correct. So your answer here will be option C. Both 1 and 2. See now if you see that the Bangladesh Liberation War and all they are discussed and this question was easy for us to answer. Likewise if you see the quiz question they are also based on some of our article discussion. So if you had keenly observed the discussion you can easily arrive at the answer for those quiz questions. We will all answer the question in the comment section and the right answer will also be posted in the comment section itself. And displayed here are two main practice questions for you. See go through the question and try writing answer for these questions. It will be really helpful for your main examination. And that's all for today's discussion. If you like this video do like, share and comment and don't forget to subscribe to the Shankar Is Academy's YouTube channel. Thank you for listening.


to Exotic Wine Travel. I am your host, Matthew Horky. Hi, I'm Sherin Tan. Welcome back to the show today. This is an exciting episode because we are going to talk about our two-month experience with the Coravin Wine Access System right here. So before we get started, I wanna thank Coravin for sending us a sample of the Coravin Model 2 Elite to use in our video series on sipping Santa Barbara, Recommended Wines and Producers book. We wrote about the wines of Santa Barbara County. Other than that, this video has not been paid for in any way. We're just giving our feedback. And for those of you who don't know, Coravin is a wine access system. And what it is, it's designed to extract wine without pulling the cork. So what happens is there's a surgical grade needle. You stick it on a device, we'll show you later. You insert it into the wine, it pumps out argon gas into the bottle to protect the wine from oxidation.  Cork bottle's supposed to stay fresh for several years. That's what Coravin claims. For the screw cap, which we're about to use, they say three months. So let's talk about, we've had experience with Coravin before, but it's before we were using it on a daily basis. What do you think after two months of use? With that, we have friends who are using Coravin and we tasted the wine set we'll end in a cork bottle for a few months and it tasted nice. But this time around it's a little bit different because we tasted it when it was fresh and then we tasted it again a couple of days later or a couple of weeks later. Still tastes good, but this is the very first time that we are trying it from the bottle. At first, or even now, you can't say that you 100% trust the product unless you have your own personal experience, right? I do think that, you know, I don't get any oxidation notes or whatever from all the wines that we tasted, but I still somehow think maybe there is some slow oxygenation or something like that. I don't know. She wants to be a little bit skeptical. We will film when we come back, we're leaving the US soon. When we come back in the US in a year or maybe another couple of years, we will access bottles that we've opened and see how they've developed after two years. So I personally have been loving the Coravin because we can taste a bunch of different wines. If I want just a glass of something, I can have a glass of something without opening the whole bottle and wasting the wine, right? Yeah, just last week, we had the Laundry 1 wine lover, Judy Matio, and we opened how many bottles? 15 bottles at lunch. Three of us, I mean, that's the good thing about Coravin, you can try a lot. So the proof is in the pudding. We are gonna open a wine right now that's been opened for almost two months. And this interesting thing about this is this Coravin just released the screw cap top. And what happened, we did it before, I'll put it up on the screen.  It has a membrane and you're supposed to be able to use the Coravin Model 2 with it and we're gonna see how it is.  Yeah, but you were pretty quick. Yeah, I was gonna claim that this is supposed to last three months. This was opened on February 13th, 2018 and we're filming this on April 2nd, 2018. So almost two months. Let's give this a go. This is the Stoltman Vineyard Sauvignon Blanc 2016. This was surprisingly good when we tasted it. Remember we were actually very crisp wine. It doesn't show in terms of color. This is a clear bottle. Any notes of oxidation, which is good, right? Let's give this a go. It's not too cold. Let me show you how to use it. You just clamp the Coravin on like this. Clamp it out nice and tight. I just purge out the needle with argon to make sure there's no oxygen in it. Then I'm gonna insert the needle right through the membrane and let's see how this tastes. You just pump it right here. Short, quick pumps. I'm just gonna put some in yours and you can dump it in mine. And what this does is it puts argon in so that displaces out the liquid and pushes out the wine outward like this. I've actually found people have complained about cartridges running out too early. You know, we went through 30 samples about a pour about this big before our cartridge ran out. Cartridge is supposed to last actually three whole bottles. Here's where the proof is in the pudding and Sherin is a super honest person so we are not going to hold back Stoltman 2016 Sauvignon Blanc from Santa Barbara County, California. Let's give it a go. I have, in other occasions, I felt like the wines did taste different even though it wasn't oxidized. But this one, no. This is really separate. I was expecting, and you can see a little gas, I don't know if you can see this, a little bit of gas bubbling up for the argon mixing up with the oxygen. I am very shocked. I picked this bottle because it's aromatic, it's fresh. It would probably, if there were signs of oxidations they would be showing on this. Smells pretty darn fresh, let's see how it tastes. What do you think? It's still fresh. Sherin's very picky, I mean, obviously, wow, this is really impressive. This is someone young, Blanc grown on limestone soils. Good job by Corvin. I guess this is gonna get a thumbs up and we're just gonna have to do future videos in the future to see wines that we have accessed for over a year. I think that will be very exciting. I'm skeptical again, but you know, we'll see. Thank you Corvin so much. Guys, if you liked this video, please subscribe to our YouTube channel, Exotic Wine Travel. I will see you as the next episode.


The hydrophobic gating model suggests that ion permeation through pores is inhibited by the hydrophobicity of the pore walls, rather than a physical occlusion of the pore. This model has been studied extensively in potassium channels, but its effects on the function and structure of these channels remain unclear. In this study, molecular dynamic simulations were used to investigate the effect of hydrophobic gating on potassium channels. It was found that the activity of potassium channels is strongly correlated with the hydration level of their cavities, suggesting that insufficient hydration is a major obstacle to ion permeation. Furthermore, enforcing dehydration of the cavity caused the channels to transition from one state to another, indicating that the dewetting of the cavity is a crucial step in the gating process of potassium channels. These results suggest that the hydrophobic gating mechanism is responsible for the regulation of potassium channel activity and structure. This article was authored by Ruoshu Jiu and Bert Eldergrut. We are article.tv, links in the description below.