okay that's scary it is so cheap that you can yell let's go how's it going everybody dahtodoy here back with some more dragon ball fighters ranked matches this time playing a team of Goku blue Vegeta blue and Bardock really I just wanted to play Goku blue and Vegeta blue but Bardock biases gives a lot of stun time so it also allows Goku blue to get some crazy stuff and it allows Vegeta blue to get some crazy stuff I don't know if we'll be hitting any of that against a dragon ball super broly player but hey if it happens up wait I just realized is are they playing Kepler that they just have a Kefla icon okay well that's disappointing if it was a Kefla player we might have gotten the UI dramatic finish dude I would have been stoked look at me thinking about what could have what is going on I was reminiscing on better times that never happened I guess they weren't reminiscing then hey I'll take it okay all right we're done talking about the past that also wasn't the past because it never happened let's go Vegeta blue help me out of this ain't no super dashing loud vanish I'll go low I'll have to go low make him go mid screen three bars not gonna spend any of it obviously wow he is dude he is grabbing I don't know why he did that but it scared me all right let me just uh oh no that was supposed to be my bad my bad okay I always forget that the punch is the other but I always think of the punch is the other button my bad we stop a super dash I'll take sliding three bars not gonna use it for much whoa okay gotta stop jumping in that was my lesson learned Broly thank you okay I don't know if the lesson needed this this much imprinting on me wow that was a lot of damage oh god okay dodge it oh no wow he had me he had me ready do it he's vanishing everywhere all right there we go all we have all we have to do is loop drop the loops that's fine course correct even if you can't finish a full serving of loops some are better than none as Evan wow Goku blue solo on health you know I gotta start it off risking it walk that get rid of that oh that is so cheap that you can dash out of that why did you that oh it's fine we're gonna recover we're not dead yet I can't believe that I called the assist out but in no world that I think it would actually it level one to Goku blue level one to Vegeta blue stack on a Bardock on top and I think we got ourselves a game that was a really fun one I feel like I was just getting constantly attacked there was that one section with Broly there where it was just Dragon Ball I could not see where Broly was going teleports vanish it well vanishes the teleport command grabs now I'm just gonna 2h watch this something he didn't he didn't see assist see us is gonna seal the deal into Broly's auto combo in the corner we all know where Broly combos go from here am I gonna get sparked again no okay the earliest the early sparking seems to be an anomaly that did hit me oh what a smart decision oh and I got reset I didn't know how that would work all right we'll take that that was scary I definitely got reset like three times that I did not see any of them coming really I didn't expect to reflect I thought I'd get a 2h my way back dash heavy talk to me then Broly say what you gotta say I think he's saying it I think he's saying it pretty loud and clear he does not want my health bar sticking around all right vanish now these keyblasts they'd get buffed if he super dashes oh I'm bad at the game though I am bad at the game you can't trust what I'm gonna say I am bad at the game you were supposed to you're supposed to big bang there that's another buff they gave Vegeta blues the ability to big bang there you can also super out of it I didn't have the bar though so I was just gonna go with the the classic special move speaking of not having a lot of bar my health bars looking a little low what a shot oh what a back dashes what man this guy is firing back nice vanish again no no it's fine we're still alive oh 6m caught us man he's gone for the 6m a lot but I'm so afraid of that command grab that it never pat it never crosses my mind to really look out for it nice super dash I'm gonna mash why did I do it why did I do it whoo love to see it I will take that to age yes correct read on my part he is oh god he is if he's getting hit by these these that means he's he's hitting something yep if he was getting hit by that that many he was doing it but is that fast or slow please punish it good we're gonna have to go at the bar dock though to finish that up bar doc gotta finish the plate please finish your plate no no I messed up oh no bar doc come on your your your son was watching bro you gotta finish your plate where are the manners oh Broly is just destroying me this is the Broly show right now okay two bars nice oh it's Broly combos okay it still didn't get too bad I mean it got bad I'm mashed I mashed again I was afraid of either 6m or not dragon rush just a command grab from Broly you know what we can still win this I'm gonna I'm gonna call it we can still win this that was sick over here it's a transmission come out let me seal the deal Broly's gone you I go who's gonna be a problem but if we get through him it's all over okay did not no no no no you're not supposed to do that oh my goodness oh what a 2h no you I go who see assist he didn't use it aww double that was crazy the 2h to UI assist bro I gotta say after that game I think I think if I could say three words to this guy it would be leave me alone I that game was does a reckless alright back dash this time yeah super dash I'm not too shocked I'm getting attacked but and he does reflect to I never expect reflect I expect more um oh caught me I expect like a super dash or maybe like a jab here in there I guess it's DBS Broly so he doesn't really have a fast normal you know what I'm making the call I think early sparks the wave here I think this is the game for early spark we need to establish a dominant lead get a few of these characters down so that we can move on to the next one let me go let me go let me talk to him please I know I was too high I know I did the vanish way too early but forgive me forgive me just this once Broly okay don't want to forgive huh forgive and forget not in your language I guess he just he does do a lot of yelling let's go okay that's scary it is so cheap that you can yell give me that dude it's so that falling move is so cheaper that situation I don't remember what it hit me beforehand but whenever he fought I'm stunned that was the most I'm alive go go go operation save blue Goku was a go okay it's fine and we saved blue Goku that was the main goal that was the most Broly play I've ever seen in my life that was the most that was the most blue Goku play I've ever seen a lot where I didn't even know he had DBS Broly see assist all right can I just get bar dock out here I know it costs an extra bar for no reason but I got to protect these assists man I don't got sparking to look back on anymore I need these assists I never expected whoa come on nice all right I don't even know if this will kill to be honest blue Vegeta impressed me I'm not impressed I'm impressed again let's go I'm impressed I knew that dragon was gonna hit I was landing I was just like yeah let's go dude I'm ready now it's just you I Goku will he do the comment how again will he Super Dash I don't know I'm jumping in nope he's yeah I didn't even I don't think I meant to click Super Dash I don't think so I mean I could have it's me I Super Dash I I all I know is breathing fine dining and Super Dashing but I don't think I meant to the oh what am I stupid I'm alive Operation Save Blue Vegeta is a go oh and I messed up royally Operation Save Blue Vegeta oh I threw a key blast through key blast instead of blocking both equally viable strategies oh that move is cheap I you like Goku's number one in the game it's just facts oh my god it's just it's logic I do actually think that though like what do you do bro what do you do well obviously I played that one really poorly but that move is medicine dude that to age is a menace you cannot it's just not free I mean there's things you can do but then you I Goku kind of has stopped doing this you know it's what now you just know it's a weakness this classifies is bullied oh I did I didn't block all right we got to bring it home with blue Goku I'm getting bullied by that move three bars while I can I can raw level three right now I think I got my answer oh he just wasted it all don't switch yes we're still in the running wow hmm that was a very close game we were getting bullied bro bro why did none of you that are watching this video step in to stop that somebody should have intervened that was did you see the Broly stamp I could tell from the very DNA of that player that he had a Broly stamp ready I just didn't know it until I saw the stamp all right we found another match and this opponent is a great priest rank so that is the second highest rank in the game and he's playing jeering up on point and this is kind of like a nothing detail but his profile pictures were all jeered he's got the background I think I'm gonna we were talking about bullying before I think this is going to be the next level beyond he's also playing the popsicle jeer hold on oh and he's got he knows the sea assist that's a great sea assist people sleep on that one I don't know about that be assist oh dragon rush caught me asleep at the wheel I needed somebody wake me up if I'm gonna if I'm gonna win this game I need to be wide awake get off of me oh that would have been sick I try to get a vanish in there I thought he'd go for a grab of some sort whoo hold on hold up we're not out of it just yet I'm gonna spark nice alright I'll take this I can't believe that didn't work I got a so nice I had to attempt it what is with me what is with me he boy went for the match he knew I was gonna mess up the mash and scramble is so good oh that messed up the that messed up the uh I'm really spamming that move we got a cool it on that oh that would have worked whoo nice to us I think would that have hit me even if I went behind I don't know but it looked like a read now what a drug yeah I gotta give myself if I'm giving him credit I gotta give myself credit on that one that was a great um dragon rush there boom Niagara pommel down into the ground we have a little bit of a health lead on scene go on but again we use spark really early oh beautiful what a clash oh nice bit of a scramble win for us there come down let Bardock do the rest of the talking Vegeta you take it easy take it easy on the sideline all right if we can just get done with Vegeta no assist are left beautiful key blast I was really looking for another rocket kick once he did it once it was kind of on my radar couldn't even 2h that I don't think you thought I landed on that side take him down a peg okay spark get that out of the way no defense come on now is not the time for my defense to be failing me so spectacularly does a level 3 kill he doesn't want it bad reflect I panicked I panicked I should have just blocked I should have tried to buy more time it's coming down to a match of a genus super dash I never thought it would happen not like that man this has been a wide range of a video fighters I feel like we got a really talkative fun match and now we're in the serious so it is no fun zone it's I'm not having fun I didn't block the overhead that was the I feel like that was the simple option to I definitely thought he'd run in low or dragon rush or something like that that's where all my focus went game one it it went okay for us but we couldn't bring it home that's the disappointing part especially since we took so many victories on like scramble scenarios so now we got to play a more honest game down tech super dash classic definitely did not expect to see that all right he seemed to try to reset us a lot classic jeering oh it was too slow if it was a bit faster that would have been a great choice but that third hit of Goku blue is not for the scramble that is for the block pressure that is bad news for us he tech that you're in you're in you got you go past the defenses oh okay you're good you're good you win you win get him back in that corner oh that's so fast jeering you're so fast you're so good jeering you're so good I listen I thought you were good since season 3 season 3.5 maybe crazy all right we sparked there nice reaction time as well we're dealing with a jeering player he's got the reaction time our cancel out every option covered oh what a raw tag as well don't challenge him don't challenge him I didn't listen to my own advice why am I challenging I keep thinking that if I mash the good results what happened we got oh man we got to clean it up I think it's too late to clean it up honestly no it's not oh I didn't block low okay hold on focus I want if I'm going out I want to go out with dignity at least I'm not going out with dignity am I all dignities long gone it's time to just pack our bags fellas don't let them see our tears don't let them see your tears fellas we're going out with pride ah was that gonna hit oh it did it did hit we're going out with no pride arxist give me one more game arxist I know it says two but patched another game for your boy please just one more caddy one more game don't take me away from this arxist


what's going on guys it's your boy DPJ here today with another destiny video and in today's video we have top five warlock nova bombs of the week and some of the clips you guys have submitted are absolutely insane they really are now we had titan fist of havoc last week and we're doing warlock nova bombs today and I will do a probably a golden gonna blade dancer in the next few days so if you have any amazing clips be sure to send them into the email I just linked in the top of the video in the description now enjoy the video and I'll catch you on the next one heavy ammo available three opponents down fantastic work I can't believe what I'm seeing we all on YouTube every damn day watching these videos of brand new games bid at the bid many are the same that's why you gotta go and find DPJ destiny gameplays weekly snipes heavy uploads gonna have you a hype started in the UK now he's worldwide DPJ go and subscribe


All right, so we're going to go ahead and get started. The PGY2 class, we're presenting the afferent anatomy, and then we're also going to go over some relevant clinical diseases. Kind of a brief overview, touch on a little bit of what's in the BCSC, and I think some of the others have brought in some other information as well. Tina is going to join us as soon as she can get here. She's taking care of a procedure this morning. So I'll start out with the visual pathway here. And this just is the brief overview that you can get kind of looking at everything that's involved in the afferent system. Includes everything from the very front of the eye, from the cornea, through the eyeball, to the retina, to the optic nerve, through the apicaeism tract, and into the brain, and into the visual cortex and the occipital lobe. So all of these pieces are susceptible to damage and susceptible to injury, and can cause different types of disease states that we worry about. As far as the retina goes, here's your overall view of the posterior pole here. This is your fovea, this is your macula, optic nerve. We all take a look at this every day. The things to keep in mind here, and these are kind of points that are emphasized in VCSC that will be important for OCAPs, are just these kind of nuanced measurements that you sort of need to memorize. The optic disc, where it's located, creates a physiologic blind spot that's about 17 degrees from the fovea. And the size of that blind spot is about, if you roughly remember, five degrees. That will be close enough approximation. It's actually a little bit larger in the vertical plane than in the horizontal plane. And that's just due to the different shape of the optic nerve in the vertical plane. The fovea itself normally measures about a disc diameter, which is about 1.5 millimeters. And it's located 4 millimeters temporal and 0.8 millimeters inferior to the optic disc. So you can see it's not exactly horizontal straight across. And that's another good point to remember. As far as the orientation of the nerve fiber layer within the retina, you can see that there's radiations here. And that's important to keep in mind that these cells that are coming in temporally here pass through this horizontal graphene. And they're going to course over the macula. And so when you have injury to particular areas of these vessels that are feeding these areas, you're able to correspond the visual deficits to where those nerve fiber layers are injured. And then the other thing to keep in mind is that as you get more nasally here, you're going to have these fibers coming in really steep angle. And that will cause some of these bow tie configurations, which some of the other presenters are going to go over a little bit later. As far as the really super high level, super low level detail of the cellular organization, I'm not going to go over everything today. Dr. Manlis is going to touch on a lot of this in his lectures. But the important thing to remember is that light pathway actually comes, the retinas sort of flipped upside down. So the photoreceptor cells are actually the furthest away from the light pathway as it comes in. There are a few of these ganglion cells that are located right here in the ganglion cell layer that actually do have some light sensing capability. And these are called these internally photosensitive ganglion cells here. And then the light signal passes all the way through here and gets processed in the outer segments of the photoreceptors. There's also a number of other cells in this section that are important to know about. So bipolar cells are important in vertical transmission of information. These other cells here, we have amocrine cells. There are some interplexiform cells that aren't labeled here. And then we also have the horizontal cells, the horizontal cells that stretch across. And those are actually important in signaling between photoreceptors and between ganglion cells, which is important in distinction of contrast and also in determining spatial location of these light signals that we're getting. And then the last sort of anatomical point that I want to point out here is that in the center of the retina, right in the fovea, there's almost a one-to-one ratio and generally is a one-to-one ratio of the photoreceptors to the ganglion cells. And that's important because you want to have your highest sensitivity of picking up those visual signals in that area. In the periphery, when you get further out, the ratio really expands and it gets out to about one to 1,000. So you see this one ganglion cell here. And this is just obviously a cartoon demonstration. But one ganglion cell is supplying hundreds and thousands of photoreceptors, which is important for processing information and being able to synthesize and say, OK, I know that there's an object coming from this way. That's the important piece of information that I need from that signal. Then I can turn and look at it and see the object and make out more details. I'm not going to go over any of these in any great detail, but the BCSC presents a couple of examples. Basically, any type of retinopathy is a problem affecting the afferent pathway of the visual system in terms of the retina. A couple of these important points to know I've highlighted here. Vitamin A deficiency is one that we probably don't think of all that often, but it's one that can cause problems with the photoreceptor signaling. And the key finding here is that if you were to do an ERG on somebody who's low in vitamin A, you would see rod dysfunction. And then a couple other things. We always are screening patients who are taking placonil for lupus and various other rheumatologic diseases. So the important thing to know is that that risk of damage, that bullseye maculopathy that we see with placonil, is increased risk with duration of treatment greater than five years, and then also with a cumulative dose once it exceeds 1,000 grams. And typically, the recommendations are to screen one year into treatment or any time during that year, and then annually once patients have been undergoing five years of treatment. So you don't have to screen patients every year when they're on placonil. And then there are also some perineoplastic syndromes that are associated. So last point I want to make about the retina is that when you have a patient with decreased vision and you're trying to sort of parse out whether this is an optic nerve or a retinal problem, these are just a couple of things that you can consider. They're both going to have vision changes. So that's common to both pathways. But in terms of the other things that you can look at, color vision is going to be slightly different between the two. Typically with retinopathy, the amount of color vision loss, if there is any, it parallels the degree of visual acuity loss. Whereas if there's optic neuropathy, there tends to be a more dramatic change in color vision. So that's a really quick and easy test. You can do it at the bedside. If you're doing a consult, bring your handbook and just go through those color plates. And even the basic most simple test is grab your phenylephrine and hold the cap up and just test color sensitivity between the two eyes. Secondly, I want to point out that metamorphopsias and photopsias are much more common in retinopathy. And particularly, photopsia usually indicates a problem in the outer segments of the retina. You're rare to have an afferent pupillary defect with a retinal problem, whereas you're more commonly going to have one if there's an optic neuropathy. And then lastly, and this is kind of a subtle distinction because there are some conditions where you will have scatoma in the retinopathy. But typically, there's more distortion of the lines in the Amsler grid with retinopathy as compared to just chunks missing when there's an optic neuropathy. All right. All right, so picking up where Becca left off, the kind of next step in the afferent pathway would be the optic nerve. So this is basically the confluence of those axons of the ganglion cell layer. Again, some numbers kind of picked out from BCSC that seem to be very testable on OCAPS. So a confluence of about 1 to 1.2 million ganglion cell axons. And then they exit through the lamina cabrosa, which contains approximately 200 to 300 channels. So that fact that this is a relatively small number of channels for a lot of axons.  I totally agree. Yeah. Yeah.  It has nothing to do with taking care of it. Yes. Absolutely. Yeah. A lot of nonclinical information that seems to be tested. We actually brought that up in our, as we were discussing preparing this lecture. So the combination of that fact paired with kind of this unique blood supply, which I'll talk about in a second, is responsible for the particularly sensitivity of the optic nerve to all different types of damage. So whether it's ischemic, inflammatory, compressive, toxic, metabolic, lots of different things. We've touched on it a couple already. And we'll touch on a few more as we go through the lecture. Some of the measurements. So the diameter of the optic disc, it's approximately 1.5 millimeters at the optic disc. And then about 3 millimeters after it acquires its myelin coating. And then if you include the optic nerve sheath, it's about 6 millimeters in diameter after that. So just posterior to the sclera, I kind of mentioned this, the optic nerve requires a dural sheath. Clinically relevant in this point is that it's contiguous with the periorbid of the optic canal and then the arachnoid membrane. So you do get this channel, the sub-arachnoid space, that choruses all the way up to the posterior globe and is contiguous with the rest of the sub-arachnoid space of the cranium. So any elevation, as we've all known, have seen at this point, most likely, elevation in ICP can really be visualized quite well often in the posterior pole. I actually saw a guy in clinic yesterday that looked probably worse than this and is going to get an optic nerve sheath fenestration today. And then it's also just important to note that in the optic nerve, at least in the retro-bulbar space, there is an approximate retinal topographic representation that's maintained, but later we'll kind of see that that can get rotated and changed. As far as the blood supply, so the optic disc and then the bulbar optic nerve before it actually leaves the sclera, receives a blood supply largely from the branches of the posterior ciliary arteries. And I've seen in some places, actually doesn't mention this in BCSC, at least not in the neuro section, but there's this circle of Zinn-Holler that is mentioned in a few of the pictures that I looked up. But then the retro-bulbar, the orbital optic nerve, receives a blood supply largely from small peel branches coming off of the ophthalmic artery, not the central retinal artery itself. The central retinal artery and vein travel within the anterior 10 to 12 millimeters. So they actually travel underneath, but then they'll pierce that optic nerve sheath at about 10 to 12 milliliters posterior to the globe. And then this, I don't really go into this. We'll probably talk about what's in the superior orbital fissure outside and all that stuff. But I wanted to bring this up because it did talk a little bit about the anatomy. So the optic nerve travels posteriorly through the optic canal. And within the optic canal, we have the ophthalmic artery that traverses the optic canal with the optic nerve. And then it is separated from the superior orbital fissure by this optic strut, which terminates superior is the anterior clinoid. And that seems to be a landmark that's talked about not infrequently when we're reviewing MRI and CT images. And then the optic canal is 8 to 10 millimeters long, 5 to 7 millimeters in diameter. And it's anchored tightly within that canal. So that's why a lot of these traumatic injuries can cause some shearing forces to the optic nerve and cause damage right within that canal. Next, we talk about the optic chiasm. So it's the 8 to 12 millimeter intracranial portion of the optic nerve, or where it terminates. And then it measures about 12 millimeters wide, 8 millimeters long, and 4 millimeters thick. Located anterior to the hypothalamus and third ventricle. And then it's blood supply. This comes up over and over again. Blood supply of the various portions of the afferent system is from small branches off the proximal anterior cerebral and anterior communicating arteries. As far as the location of the optic chiasm relative to the cella, we talk about that most are just superior located, about 10 millimeters above the cella. But there are about 17% that are located anteriorly or what we would call prefixed, and 4% that are located posteriorly. So here we're just, so this is normal where the optic nerve comes. The chiasm is just right above the cella and the pituitary. But then there's this prefixed orientation where it's just anterior and then post-fix where it's posterior. On MRI, I pulled up some pictures that you can kind of see this as well. So this is normal with the optic chiasm here, pituitary. And then we've got an example of a prefixed, a little more anterior and then a post-fixed, post-fixed, a little more posterior. Within the chiasm, as we all know, there's crossing of fibers. So it's the nasal retina and it's approximately 53% of those fibers cross the opposite side. So a superior temporal visual field defect contralateral to a central scatoma is helpful in localizing a lesion to the junction of the optic nerve or a junctional scatoma. I'll show a couple examples of visual field deficits like that on the next slide. And then also it mentions that macular fibers tend to cross posteriorly. And so if you get a posterior lesion on the optic chiasm, then you can get this bi-temporal scatomatous field defect. Here are a couple of examples. So lateral chiasmal or junctional lesion can cause this ipsilateral central scatoma. I couldn't find the best representation but contralateral temporal hemianopia. And to some degree, a lot of the visual field examples I brought up, you know, it would be more of just a superior temporal defect and then a central scatoma. But you could get this temporal hemianopia. If it was posterior central chiasm, then because those macular fibers cross posteriorly, then a lot of times you'll get this bilateral hematomous temporal hemianopia. But this again can be in degrees. So it could be just more of a central defect. But if it's a more extensive lesion then it can grow to be almost complete. Some of the common offenders, and that you'll see or at least we'll see as we rotate through neuroclinic or pituitary adenomas, paracellar meningiomas, cranioferringiomas, so on and so forth. But you also have to consider infectious inflammatory and then neoplastic or lymphocliferative. Okay, our questions are numbered a little weird just because I was too lazy and didn't go change the numbers. But so these, I guess we can do them just as we go along if that's okay. It'll mix things up. So here's just a few questions based off what we talked about so far. So if we're keeping track, you can just write down our honor system or whatever. So approximately how many ganglion cell axons contribute to the optic nerve? What's that? Oh yeah. Bonus points for that, so okay. And then true or false, the ratio of photoreceptor cells to ganglion cells is highest in the periphery and lowest of the phobia and which cells participate in signal processing within the rental layers. And that can be multiple answers. I can't remember if the next slide is, oh, I can see. Okay, this is the answer. So if everyone is ready, there's the answers. All right, I think that's it. You're about the second one? Yeah, that was true. Yeah, it's the, no, it's, so it depends on how you read it. So it's photoreceptors to ganglion, so you have more. So the ratio is, oh, I mixed that up, okay. It's true. Yeah, it's true. You have less photoreceptor cells. Yeah, no, I was thinking if it's a smaller ratio, if it's one to 1,000, but I mixed up the wording of the question. Sorry. You guys got it, you get the point. All right. So it's interesting how the optic, from the fibers from the retina rotate about 90 degrees as they travel through the optic tracts and through the lateral geniculate nucleus. So this is a picture, like a cross-section of the lateral geniculate nucleus. And as those fibers come through, the upper retinal fibers actually rotate 90 degrees to lie immediately in the LGN. And the lower retinal fibers rotate to lie laterally. And in the center, it's called the hyalum, we have the macular fibers. And the way I remember this, just lowers lateral retinal fibers. And the optic tracts themselves, they proceed circumferentially around the hypothalamus. And right before they hit the lateral geniculate nucleus, the pupillary pathway fibers branch off and they go to the pre-tectal nucleus here. So the pupillary pathway is separate. These fibers actually correspond to non-visual retinal ganglion cells, SL axons, that are in the retina itself. And then there are also, there's another offshoot of fibers that project onto the suprachiasmatic nucleus itself to regulate our diurnal cycles too. So the LGN, it's shaped like a mushroom. It's located in the posterior thalamus, on the lateral to the midbrain. And it has a dual blood supply. So from the internal carotid artery, the anterior carotid artery corresponds to the blood supply to the macular region. And the posterior cerebral artery has an offshoot, the posterior lateral carotid artery that corresponds to the blood supply in the medial and lateral aspects of the LGN, you'll see a picture of that soon. And the LGN itself is divided, the gray matter is divided into six layers that are tested again. So going from inferior to superior, the inferior levels are the M cell fibers or the magnocellular fibers that have axons from the retina itself again. And these are responsible for motion detection and it's the larger receptive field. The four superior layers are the P cell axons that are part of the cellular. And these have to do with spatial resolution and color perception. These are just mind mnemonics, so M for motion and P for pretty colors. And in between those layers, you have the K cell axons. These are still under investigation, you don't know exactly what they're responsible for, but we know they're somewhat responsible for color vision as well. And also if you notice, one other way to memorize this is going from inferior to superior. It goes in alphabetical order, M to P. And then sometimes these layers are tested as well. So layers one, four, and six receive axons from the contralateral eye here. And two, three, and five receive axons from the ipsilateral eye. So as you can see, each eye has a magnocellular layer and two parvocellular layers that correspond to it. And I'm not this will be useful, but my mnemonic I came up with again for this is that the ipsilateral size has all prime numbers that are in a row, so two, three, and five, not like one, three, and five, but always two, three, and five. So going further back to these, the axons that originate from the retinal ganglion cells actually terminate in the LGN. And then you have the second order neurons that arise from these ganglion cells. So lesions beyond the LGN in the optic radiations and beyond actually have normal pupillary light reflexes because we saw how the light pathway comes off off of the fibers before the LGN is hit. And you actually don't see optic atrophy because the second order neurons are the ones that are affected. And it's also interesting how the optic tract lesions and LGN lesions have their own type of typical visual field defects. So we see that in all retrochiasmal lesions there are contralateral haemonomous haeminopias. But in the optic tract and LGN lesions these are incongruous specifically. So this is thought to be because the nerve fibers of the corresponding points in the retina. So for example, the left eye right upper quadrant and right eye right upper quadrant because of the rotation of the fibers and the difference in the blood supply as well between the lower retinal and the macular fibers, the corresponding fibers don't lie exactly adjacent to one another. So if you have a common lesion like a compressive mass lesion or aneurysm that causes these type of defects, it can affect the fibers of one eye but not the other. Ischemic insoles are less common. I can show you here, this is the kind of defects that these ischemic insoles often form. These are sectoranopias and sector sparing haemonomous haeminopias. So you can see here again the hylum which corresponds to the macular region is supplied by the posterior corridor and that comes from the posterior cerebral. So you see this contralateral haemonomous horizontal sectoranopia and the lower retinal fibers in the lateral region and the upper retinal fibers in the medial region are supplied by the anterior corridor artery and they can form the sector sparing haemonomous haeminopia. So optic tract syndrome is a triad of typical findings that we see in patients who have optic tract lesions. The three things that we usually see are incongruous contralateral haemonomous haeminopia. We actually see an RAPD on the contralateral eye. So this is because the majority of the optic tract is composed of fibers that have already decasated. So they're mostly nasal fibers and so more of the contralateral eye fibers are hit than the ipsilateral eye and you see a contralateral RAPD. You also see a bilateral RNFL atrophy or optic atrophy in this sort of bowtie configuration you can make out here. It's subtle sometimes when you're examining patients but it can be a clued as to where the lesion is. So why does that happen? We actually saw this in a patient during neurology or neurology rotation. So it's a little bit confusing but if you look at this picture it starts to make a little more sense. So you have the optic nerve here and this is the nasal area, nasal retina, nasal to optic nerve and then you have the macula temporal to it but in the nasal half of the macula the fibers enter right here right here at the optic nerve and all the nasal fibers seem to enter in this bowtie configuration and the temporal fibers enter superiorly and inferiorly. So with unilateral bowtie when you see that it's usually because there's a contralateral optic tract lesion because the contralateral eye hasn't corresponds to the nasal fibers and then the bilateral bowtie atrophy that corresponds to chiasmatic lesions because that's where the nasal fibers decasate so both eyes are hit. So this is a better visual description of what's going on there. So in the optic tract lesion you see the unilateral bowtie and you see the sorry, unilateral bowtie on the contralateral side and the ipsilateral side has a temporal pallor to it. So you can see here in the optic tracks the nasal fibers from the contralateral eye make it over and the temporal fibers from the ipsilateral eye travel this way and you can see it why there would be a configuration in that sense and this is an example of a patient with an MS lesion in the optic tracts. So finally the last section here for me the optic radiations. So the second order neurons they connect at the LGN and then project back to the occipital cortex and here there is again a 90 degree rotation but there's a correction of that 90 degree rotation. So the lower retinal fibers that were originally lateral are again lower and the medial retinal fibers are again, or the upper retinal fibers are again upper rather than being medial. So the inferior fibers, they travel a bit anteriorly here through myr's loop and then project posteriorly to the occipital cortex here and the superior retinal fibers in the parietal lobe they project just straight back instead of going anteriorly first. So you see the typical pie in the sky and pie on the floor lesions where you have the peripheral contralateral hematoma superior quadrantinopia and anterior temporal lobe lesions and you have the contralateral inferior hematomous quadrantinopia for the parietal lobe lesions and sometimes we'll actually see that patients who have these lesions end up having almost like a hematomous hematopia but if you look closely you can sometimes see that their defect is denser superiorly for temporal lobe lesions or denser inferiorly for parietal lobe lesions. And usually these lesions are called the ischemic insults in the MCA territory. Sometimes we see the compressive lesions as well of course. All right, are you ready for some more questions? Second set of questions. I'll just read three of these. So why do lesions and the optic radiation show no optic atrophy on exam? Go to the next one. What type of visual field defects do patients with optic tract lesions have? Is it contralateral? Is it ipsilateral? Is it congruous? Is it incongruous? And this third one hopefully my nemonic maybe helps somebody. Fibers from the right cell, parvocellular, right eye sorry right eye parvocellular ganglion cells will terminate in which level of the left LGN. So right eye, contralateral LGN, which levels are affected? And this is one of those test questions that come up sometimes. Last one, in the triad of optic tract syndrome on which side is the RAPD observed? Ipsilateral to lesion or contralateral to lesion? The answer is here. So the reason why we don't see optic atrophy when we don't examine lesions in optic radiations is that it's posterior to the LGN. So that's second order neurons and we don't have that optic atrophy. The type of lesion that we defect that we usually see on visual fields with optic tract lesions are incongruous, contralateral, hematomus hemiopias. And then fibers from the right eye, parvocellular ganglion cells will terminate on the left LGN correspond to one, four, and six because the ipsilateral eye corresponds to prime numbers in a row, so that's two, three, and five. And the last one, in the topic tract syndrome, we usually see the RAPD on the contralateral side of the lesion because the majority of fibres in the optic tract are decasated fibres that are nasal. Good morning, sorry I'm late guys. We had to do an LPI bi-laterally on a bi-lateral angle closure patient, so I apologize. Last but not least, in our AFRIN pathway, we are finally back to the cortex, primary visual cortex, where we're going to end our journey this morning. So following the lateral geniculate nucleus, our tracts come backwards, as Straff said, both through the temporal lobe and through the parietal lobe to get back to our primary visual cortex. The center of the primary visual cortex is known as broadband area 17, or the striate cortex. And it lies back here, kind of straddling the chalcarin fissure right in the back of the occipital lobe. And that's where all of our fibres will come from the optic tract and terminate here. Kind of as Straff had alluded to, our inferior fibres will travel anterior first, and then lateral all the way around the temporal horn to end up back in our chalcarin fissure here. And like she had said, our superior fibres will come posteriorly through the parietal lobe and end up again back in the chalcarin fissure here. As a reminder, our fibres and the superior retinal quadrants will end up in the inferior visual field, of the inferior visual field will end up superiorly and the contrary is true for the inferior retinal quadrants or the superior visual field. And through all of this, we maintain a retinotropic distribution, meaning that kind of visual field pattern is maintained onto the cortex. Really importantly, remember here, the cortex is very much weighted around the macula. 60% of the cortex is focused on the first central 10 degrees of the macula. And then actually 80% of the cortex is focused around the actual central 30 degrees. So we're very macular heavy in terms of the cortex here. The superior cortex, again, receives information from the inferior visual field and we maintain that retinotropic distribution, which I didn't really know what that meant or had a hard time kind of understanding what that meant, but that just means that the pattern that you see in a retinal visual field is maintained all the way back to the cortex in terms of how we are interpreting that visual information coming to the central part of the brain and the occipital lobe. These areas are important to know. So like I said, we have the broadmen area, which is our primary visual cortex, but then we have V2 through V5, which are also these other more complicated, higher visual functioning cortex regions that I have seen come up in questions before. All of the information will come back here to V1 and then kind of demonstrate forward to these other areas, V2 through V5 for higher cortical visual interpretation. In terms of V3 and V2, we consider these to be contiguous with V1, meaning that this information kind of directly passed to both of those. V4 and V5 are important to remember because V4 is the area that's sensitive to kind of our interpretation of color. And along with that, we consider this to be the area of our interpretation of the what. What are we seeing? What are we interpreting? And that V4 is down below. I just remember it in order. So V4 kind of lower and V5 up above. Cerebral achromatopsia is basically where we aren't able to discern color at all. Patients will describe lesions in this area as seeing the world as dull. They don't see any sort of discernment between color. They will just see various shades of gray. And that means that we've hit somewhere along this pathway from V1 to V4 or the V4 region itself. V5 is important to note up here in the superior temporal sulcus that this is where we sort of discern information in terms of where. So movement and direction of objects, things coming at you being able to discern between stationary and non-stationary and where spatially, visually spatially that information is all kind of here in the V5 area in terms of higher cortical function. So then kind of focusing on occipital lobe lesions themselves. We talk about lesions in the occipital lobe as being either sparing or macular involving depending on how the occipital lobe is being actually affected by the lesion. So why do we get this macular sparing versus non-macular sparing phenomenon? Most people will agree that there is kind of dual innervation of the occipital lobe that allows for this phenomenon. The posterior cerebral artery provides the majority of the blood flow to the occipital lobe. However, there is a small branch of the middle cerebral artery which reaches all the way back and provides some dual supply for the central part of the occipital lobe. Therefore, if you take out your posterior cerebral artery but the middle cerebral artery is maintained, you'll have a homonymous defect that will actually spare the macula usually between five and 10 degrees centrally because that middle cerebral artery is still intact providing that central macula with some blood flow. If you have a situation where you have sort of global ischemia and anoxic brain injury, something like that that hits everything, then certainly we wouldn't expect to see any sort of macular sparing lesion in the cortex. And then briefly going to cortical blindness. If we're hitting the occipital lobe, I think cortical blindness can be a really interesting phenomenon. In terms of acquired cortical blindness that we see in patients who were born with normal cortical function, as far as we know, anoxic brain injury is the most common kind of global injury to this area. Traumatic brain injuries, particularly those that affect the occipital lobe directly. Eclampsia and rarely create clamsia can also cause these phenomenon, CJD, an infection. And then I also was reading about anti-epileptic drugs and there's a variety of anti-epileptic drugs that will create sort of a intermittent or non-permanent cortical blindness that can be acquired. And if you stop the AED, it can actually resolve. In terms of congenital causes of cortical blindness, so traumatic brain injury, birth trauma, occipital lobe malformation, so congenital lesions that way, perinatal ischemia, again, these sort of global ischemic events hitting the occipital lobe. And then meningitis and encephalitis in our newborns can also cause cortical blindness that is irreversible and kind of congenital right from birth. Two phenomenon to know with cortical blindness, so Anton Bobinsky syndrome and Ridduck syndrome. Anton Bobinsky syndrome is where we basically have a patient who's cortically blind, but they are in denial of that loss of visual interpretation.  I have no difficulty with any sort of vision loss. Why are you asking me that? So that's Anton Bobinsky syndrome. And then Ridduck syndrome is actually where the patient will kind of run into objects because they're not really aware of their lack of visual spatial information coming into them. So both of these are common with cortical blindness. With all of our occipital lobe lesions and cortical injuries, patients in their absent visual fields will often have other light phenomenon, visual phenomenon in those fields. So commonly complaining of circular lights or other things as the brain's trying to come up with information in those areas that are absent, I also read a few studies where if patients had recently had, say, a stroke or some sort of ischemic injury to an area, and they did have some scintillating imagery or visual affects in that area, that that sometimes was an indicative kind of sign that they may actually get some of that vision back. So I'm kind of demonstrating that the retina was trying to still kind of fire away at the cortex and keep that imaging going. I remember these two phenomenon because I remember that Anton, for some reason, he's in denial. And then Ridaq somehow sounds like a sound that I would make if I ran into something. So like, oh, Ridaq, impressive. So I don't know if that's helpful for me, for who it was. So that was kind of the majority of the cortex. It's really important to remember those V1 through V4 areas. And then our macular sparing lesions, why we may or may not have macular sparing vision, and then kind of phenomenon that can create and represent cortical blindness. Can I just say something about Ridaq? Yeah. So George Ridaq was a World War I physician who was in the trenches and saw soldiers whose little lobes had been damaged in the war. But so Ridaq's syndrome is, like you say, the person runs into stationary objects, but what's really peculiar is that anything moving, they can see. So if you were to lift up something and move it, then they can see it. But if it's stationary or just static, they can't. So it's kind of a dissociation between something moving and something stationary. One more question. I think we do this one. Yeah, so these were just actually repeat to over here. Oh, okay. What, oh, did my not, three questions on the computer. Maybe this wasn't the most up to date. But that's okay. Do you want me to just, I think, I suppose, so my first question was just, is it, so if you have, you take out your PCA on the right-hand side, where and what do you expect to see in terms of your lesion? So you would expect to see a contralateral monomest effect that would be macular sparing, given that your posterior cerebral artery was compromised, but your MCI, you would assume, would be still intact unless there was a global scheme you can dream. I think I did a true or false on areas four and five. Do you guys remember area four and area five? Wearing what? Perfect. Color vision is wear.


Hello everyone, welcome to the next lecture in the topic analyzing the spectral reference curve of commonly occurring earth surface features. In the last lecture, we started discussing about the spectral reference curve of vegetation. We have covered what factor influences the reference curve of vegetation in the visible part of EMR and we have also started discussing about the NIR portion. So, today we will continue with that particular topic. So, as I told you, it is the leaves internal structure that is the orientation of different types of cells and the air gaps that will control the reflectance of leaf in NIR portion. And I also said that leaves has typically very high transmittance and reflectance in the NIR part. And what we can decipher from this is like since each type of vegetation has like a different internal structure like some leaves will have different orientation of cells, different species of vegetation will have different orientation of cells and so on. So, as different types of vegetation will have different internal structure of leaf then essentially the NIR portion will be influenced by the type of vegetation that is causing the reflectance and may be useful in vegetation classification or species classification that is one advantage we can remember it. It is some people have like attempted it to classify different vegetation species by looking at NIR reflectance. This is one thing we have to remember. Second thing what we have to remember is I told you that the energy in NIR portion that is entering the leaf will undergo multiple reflectances that is as it encounters different different surface between a cell and air gap between a cell and water. It will undergo multiple reflectance which will cause the the upcoming reflectance to be more diffuse. That is I told you that reflectance can be specular or diffuse. And the final net reflected energy that is coming out of the leaf will be more diffuse in nature when compared with the specular when compared with say visible portion which can be specular reflection. That is normally the EMR which is reflected in a diffuse manner will contain more information about the object that reflected it. That is it has interacted little bit more with the object that from which it got reflected and it will carry additional information about the particular object. Normally we prefer to have like a diffuse reflectance than specular because specular will be like what will happen is high amount of energy will be reflected in one particular direction which may cause like a bright spot in the image which may not tell us more information about the object of interest. Say like when we look at like still come water bodies from certain angle we may get like a bright reflectance like a sun glint we call. So, such sort of bright reflectance spots may not provide us more information about the object. But the radiance which is coming in from the object normally or which is reflected in a diffuse manner will carry some information about the object of interest. So, essentially the energy in the NIR portion will be more diffuse when compared with the energy that is being reflected in the visible portion of EMR. Coming back to the general reflectance and transmittance characters of a leaf we will just look at this particular figure in the slide. So, here if you can see this particular portion is like on the left side of the axis we have reflectance. On the right side of the axis right side y axis the secondary axis we have transmittance. So, reflectance increases from 0 to 100 along this direction here and transmittance increases from 0 to 100 in this particular in the secondary axis from top to bottom. So, if you see essentially the reflectance and transmittance curves are almost like superimposable on each error like if the reflectance is low transmittance is low if the reflectance is high transmittance is high and so on. So, essentially they are like they have like a very close relationship with each error that is reflectance and transmittance. And also we know that reflectance plus transmittance plus absorptance is equal to 1 and hence absorptance is equal to 1 minus reflectance plus transmittance. So, this shaded portion in between is the absorptance or the energy that is absorbed. If you look at these particular things what we can sense is in the visible domain let us less than 0.7 micrometers absorptance is pretty high with very low reflectance and transmittance. On the other hand when we move to the NIR portion that is from 0.7 to 1.4 micrometers reflectance is pretty high somewhat close to like say 50 percent or something. Transmittance is also pretty high something around like say 40-45 percent and absorptance is quite low. And again the absorptance increase when we move to the SWR portion maybe we will study about SWR portion little later. But what I want you to just observe is compare with the compare the absorptance between the visible portion and the NIR portion. In visible absorptance is pretty dominant with very low reflectance and transmittance whereas in the NIR portion absorptance is very minimal with really high amount of reflectance and transmittance. And as I already told you this behavior this high transmittance and high reflectance is essentially to prevent the leaf from undergoing irreparable damage and hence leaf will absorb very little amount of NIR. So, maybe the visible portion and the NIR portion can give certain information about the amount or the presence of vegetation and its healthiness. So, a healthy green vegetation if you just remember the spectral reference curve we could have observed that reflectance is pretty low in the red portion and the reflectance is very high in the NIR portion. So, maybe we will just try to understand how the reflectance will vary in the red and NIR portion for a vegetation starting from its initial stages to its harvest stages. So, that is given here in this particular scatter plot. Here what we are going to see is if we plot red reflectance versus NIR reflectance. So, red is there in the x axis NIR reflectance is there in the y axis. If we can plot the reflectance we will be able to clearly decipher between a bare soil line and a vegetation line that is we will see in the later part of this lecture or in the upcoming lectures that soil has almost like a linearly increasing curve almost. So, as the wavelength increases the reflectance of soil will increase. So, essentially red reflectance and NIR reflectance it will slightly increase like this. It will be like a linear line high reflectance in red normally will have high reflectance in NIR and so on. But for vegetation as vegetation grows to like a bigger level then reflectance in NIR will be increasing and there will be strong absorption in the red portion that is low reflectance in red high reflectance in NIR that is we will come to this particular slide or this particular figure figure B here. So, let us imagine like one particular pixel or one particular land parcel which is essentially we are starting with like bare soil. Let us say it is like a small agricultural plot the farmer is going to prepare the plot for agricultural purposes. So, before agriculture the farmer will prepare the land he will he or she will water the land the land will be like prepared. So, let us say it is the point is somewhere here the reflectance the red and NIR reflectance is somewhere here. This is like corresponding like wet soil. Wet soil will have relatively lower reflectance in all the bands in compared to a dry soil. So, now the vegetation begins to sprout and begins to grow. When that happens as vegetation grows the reflectance in red will go down because of the strong absorption of red because of chlorophyll pigment. On the other hand reflectance in NIR will increase. So, this particular point may move something like this along this particular curved line that is decreasing red reflectance increasing NIR reflectance. So, there will be like a point where the crop would have reached its maximum growth cycle. After that the plant will be ready for harvest. Once it is when it reached its maximum growth cycle it may be ready for harvest the farmer would have harvested it and then this particular point may land up somewhere here indicating like a harvested land containing just like a dry soil without any vegetation. So, this is how a particular pixel where vegetation grows will typically behave. So, what is the take-home message from this particular slide is? So, vegetation has like a characteristic reflectance and if we combine the red portion and NIR portion we will be able to study about like the growth of vegetation. So, as vegetation grows so essentially reflectance in red portion will go down and down because of high absorption of red wavelength by chlorophyll. On the other hand when vegetation grows it leaves size will increase lot of its internal structure of leaf will develop and hence NIR will be beginning to strongly reflected and transmitted and hence the reflectance in NIR will increase. So, that is why if we observe the reflectance of like one particular land parcel in a full growth cycle of a crop we can observe this particular pattern in which the reflectance data moves or aligns itself. Now, we have seen general introduction about behavior of leaf in visible and NIR portion. Now, we will take like leaves in different different stages of its senescence that is different stages of its life cycle and then we will analyze how the spectral reflectance curve look. So, in this particular slide we have four different leaves a green leaf, a yellow leaf, a red leaf and a dark brown leaf. The dark ground leaf is like kind of dead leaf when sample was collected from below the tree and these three the green yellow and red leaf were still alive present in the tree itself and this is collected from on the ground at the bottom of the tree. So, this is like a dead leaf. We will start with a healthy green leaf. For a green leaf what we are observing is typical low reflectance in the blue portion, low reflectance in red portion which is like pretty low income even compared with blue and slightly higher reflectance in the green portion. After this in the NIR portion reflectance increases drastically and it remains high almost up to like say here we are talking about 1 micrometer, okay. Now, we will move the yellow leaf. Yellow leaf means there is a change in pigment from chlorophyll. Now chlorophyll has become like less dominant and some other pigments starts to dominate the leaves characteristics. So, for yellow leaf what happens is the reflectance in red also increases, reflectance in green also is pretty high and reflectance low only in blue. So, green plus red combined together will give a yellowish color to the leaf and in NIR portion still we are observing like quite high reflectance value. Now comes the red leaf. So, after this this is like another stage of maturity in leaf. So, there the leaf is strongly absorbing in both blue and green portions that is chlorophyll is like almost absent and only some other pigments are present. So, this leaf is like almost towards the end of its life cycle. So, what happens only red reflectance dominates a lot and NIR reflectance slightly reduces. For this brown leaf entire in the entire visible portion reflectance is pretty low and then the reflectance in NIR has fallen down. So, the general observation from these four leaves are if the leaf is healthy then typically the reflectance in red will be very low and leaf will be green in color because of increased reflectance in green portion by chlorophyll. As the leaf moves to its different stages chlorophyll pigment will begin to reduce some other pigments may start to dominate which will give a different color to the leaf or if the leaf undergoes stress some sort of stress water stress nutrient stress infestation by some insects whatever some other pigments may try may dominate and hence the color of leaf may change essentially it is indicated by change in reflectance in the red portion first. For a healthy leaf reflectance in red will be very low but when leaves undergo certain number of stress or when some other pigment dominates reflectance in red will increase. If you look at the NIR portion till the leaf is like almost at its final stages like for the except for the red leaf the NIR reflectance was pretty high because until the leaves internal structure is damaged completely leaves will maintain its high reflectance in NIR portion only when the leaves internal structure itself is damaged because of like the final stages of leaf or the leaf is like about to die and fall off then only NIR reflectance will go down. So, what it means is NIR reflectance will be relatively higher even when the leaf is undergoing significant amount of stress or some other pigment is dominating like normally we would have seen in our daily life that when vegetation undergoes water stress when we do not water our plants after few days its leaf color will start turning yellow and then the leaf may die right we have observed that. So, when the leaf turns yellow what it means because of absence of water the plant underwent or undergoing a water stress its chlorophyll content is beginning to reduce it is not able to sustain itself some other pigments is now becoming dominant which gives leaves its characteristic yellowish color or reddish color that means reflectance in red has already increased but till then NIR reflectance will be fairly high only when the leaf has undergone change in its internal structure itself like the leaf is now dead it is now crumbling then only the reflectance in NIR will be coming down. So, if you look at the visible and NIR portion of the spectrum only in these two parts the first signal of leaf senescence or the first signal of leaf stress whatever either due to senescence or due to stress it will be shown characteristically as increased reflectance in red portion rather than decreased reflectance in NIR band. So, you should remember this I am talking only about visible and NIR range whenever leaves is undergoing different stages of its life cycle or whenever leaves is undergoing some sort of stress it will be signaled through increased reflectance in the red portion first then there will be like change in reflectance along the different different portion of visible like reflectance in green may come down reflectance in red may increase lot in come back to green and so on and finally only when the leaf internal structure itself is going to change NIR reflectance will come down. So, visible portion if you compare visible and NIR visible is like pretty useful for understanding vegetation stress or vegetation senescence and so on. So, that is why normally we will see in later part of this particular topic coming upcoming lectures that combining NIR and red portion or reflectance combining the reflectance in NIR and red portion will help us to understand the healthy or healthiness or how or the vigor of vegetation that is present in the land surface. Till now we have seen the spectral reflectance property of vegetation in the NIR and visible portions. Now, we will move on to understanding the spectral reflectance property of leaf in the SWR portion that is wavelength starting from 1.4 to say 2.5 or even 3 micrometers. So, the reflectance in SWR portion is strongly influenced by leaves water content as leaves water content increases reflectance decreases in the SWR portion. In this particular figure given in the left side of the slide we have plotted leaves with different different water content level and how its spectral reflectance will look. Maybe we will start with leaf with 100% water content where all the air gaps are filled with water all air gaps filled with water. We call this the amount of water content leaf as turgidity. So, turgidity normally refers to the amount of water content within the leaf it is a general term we use and if a leaf is completely filled with water with 100% water we call that particular leaf as turgid it is fully turgid that is it is filled with water. So, maybe we will start with such a fully turgid vegetation that is like the dark black curve given here. This is a typical characteristic healthy vegetation curve that we have already seen with like very low reflectance in red very high reflectance in NIR. And if we compare come to the SWR portion the reflectance is relatively lower that is lower than NIR but fairly higher than the visible part and also if you look only in the SWR portion that is the 1.4 after 1.4 we can see as wavelength increases reflectance goes down linearly. So, this we have to remember in the SWR part as wavelength increases reflectance goes down almost linearly this we have to remember and also reflectance in general goes down with increasing water content. Okay. So, this is for like for healthy leaf this is this will be the curve and also there are like three strong dips like here it is not that it stops at 2.5 but there are like three strong water absorption bands in the 1.4, 1.9 and 2.7 micrometer portions of EMR spectrum that is as vegetation water content increases this particular absorption bands in this 1.4 and 1.9 will become very dominant and it will become very strong. And as the leaves water content decreases say now the leaf content is water content moved to 75 percent reflectance has increased slightly and also the absorption band has become slightly less stronger. And as we move higher and higher we can see that say we will just go to this 5 percent curve this dotted line the top line reflectance is very high in the SWR portion and the characteristic dips seen around this 1.4 and 1.9 micrometers are almost absent that is the dips are like present only like very minimally. And you can also see that even at this stage of very low water content NIR reflectance is pretty high actually like it will also increase with increasing in with the drying out of leaf but you can see that at 5 percent means vegetation will undergo like a significant water stress it will not be able to do photosynthesis with full efficiency and hence red reflectance is increased also green reflectance is increased that this leaf is not yet died not yet undergone like full effect of water stress only like water has reduced at that particular time and hence it shows very high reflectance. So, what essentially it means is the amount of water content will in general influence all portion like as the water content increases the reflectance will go down but this is very strongly seen in SWIR portion of vegetation. So, if we want to study vegetation water stress the immediate signal will be coming from SWIR portion like it may take some time for vegetation to undergo stress for the change in red reflectance it may take still longer time for the vegetation to for the leaves internal structure to completely get disturbed for a reduction in NIR reflectance. But in SWIR portion as soon as the vegetation water content changes the reflectance will change. So, this is one of like the most suitable band for understanding or for studying about how much water content a leaf has. So, as the leaves water content increases the reflectance will go down pretty fast in the SWIR portion of electromagnetic spectrum. But if we want to use these characteristic dips 1.4 and 1.9 we will not be in a position to use them because we have already seen that atmospheric absorption also plays a major role in remote sensing and the same portions 1.4, 1.9, 2.7 or water vapor absorption band that is present in atmosphere. So, when we take a remote sensing image when we take a remote sensing image we will not be able to clearly see these particular dips we will not be able to understand whether these dips are due to atmospheric water vapor or due to vegetation water content. So, we will not be using this but the other portions other surrounding portions say roughly 1.5 to 1.7 or after 2 all these things will carry certain information about leaf water content which we will use it for studying whether the leaf is having water or not. So, this particular slide gives another example of how like a green grass and a dry grass look it is like a green grass with good amount of water and a dry grass which is like almost dead at its dead stage. You can see like as the leaves became dry the reflectance increases in general in almost all bands and this is like undergone lot of stress and hence the reflectance in visible portion also has changed drastically. So, very high reflectance in red portion, green portion and everywhere but NIR still remains. So, NIR is not a very good portion to study the water stress but it helps us to study some other thing we will see later. But for understanding water stress it is always good to use the SWR portion which will first show immediate signals. It will take some lack time or sometime will be used up before water stress influences leaf pigment and causes a change in leaf colour. It will take some time and it will take further time to change the reflectance in NIR. So, as leaf dries out its reflectance will increase this is what we have to remember. So, I already told you that the 1.4, 1.9 or the 2.7 micrometer wavelength which are characteristic water absorption bands we will not be in a position to use it for remote sensing purposes because of atmospheric absorption. So, when Landsat thematic mapper one of like the early sensors Landsat 5 satellite was launched it is one of the major application was global vegetation monitoring. So, the bands were chosen such that different properties of vegetation are observed clearly that is it had bands in say green band and red band where it absorbs the pigments contained within the leaf. Then it also had a NIR portion like it had a band in this particular NIR portion which will help us to tell whether the leaf is really healthy or not which signals about leaves internal structure. Then it also had a band around like 1.5 to 1.7 micrometer range which will help us to study the leaves water content. So, different bands of this particular sensor was chosen such that different properties of leaves or different properties of vegetation can be properly observed and understood. So, essentially in this particular lecture what we have seen is how reflectance of vegetation will vary in the NIR and SWR portion. So, primarily in the SWR portion it is the leaves water content that controls the spectral reflectance property of leaf. So, just as a summary of the entire thing the spectral reference curve of vegetation can be divided into 3 portions the visible part NIR part and SWR part. In the visible part the leaves pigments or the absorption by those pigments will dominate the spectral reflectance pattern. In the NIR portion the leaves internal structure will dominate the spectral reflectance pattern and then in the SWR portion the leaves water content will influence the spectral reflectance property. So, whenever vegetation undergoes water stress it will be first signaled in the SWR portion and when the vegetation undergoes some sort of stress because of lack of water for some time or change in growth cycle there will be like a change in reflectance in the visible portion because of change in pigments. And pretty late like once the vegetation undergoes significant amount of stress for a prolonged time then only reflectance in NIR will change till then reflectance in NIR will be pretty high. So, with this we will end this particular lecture. Thank you very much.


Once you've created your type form, and you've sort of sent it out into the wild, and people are responding to it, you're going to want to monitor the process, see how many responses you have, and who's getting to it, and just see how well it's performing. You can do that by coming to analyze, clicking on that, and then using just the first selection here, which is metrics, it says monitor your type form across devices. Now, I created a type form and mean a couple of other people, we just threw in some fake data. So we would have something here. But this gives you an idea. In the last hour or so, I've had eight responses to my survey. The first thing we have over here is unique visits. That means how many different people, and we had repeats and truthfully, we only had a few people, but we had different machines. And you can look at the total, meaning every response or unique responses from individual people, those are going to be useful in different circumstances. So I'm going to leave that up to you. But let me know that everybody who started it finished it, that's going to be unusual in the real world. It took 45 seconds, shorter is better when it comes to surveys. And it says that two of the unique visits were from laptops, three of them were from smartphones. Not surprisingly, the smartphones took a little bit longer than the laptops.  And so this doesn't tell you what the answers were, but it tells you where the responses came from. And that's simply a way of assessing the performance or the reach of your type form, which leads you into actually analyzing the data, which we'll look at next.


What is up? Everybody branding it all here. Three of my favorite bets for this week's BMW championship over at Fandall Sports Book. I like Rory McElroy again this week. I know he missed the cut a week ago, lost two and a half strokes off the tee, but of the four strokes gained stats off the tee is the most predictive McElroy's gained strokes off the tee and 80% of his past 50 rounds, according to Fantasy National. So you expect that to bounce back, speed and bouncing back. A lot of strokes putting as well. But he's 11th on tour this season. The putting numbers have been good for Rory. On the year, don't have a whole lot of information on Wilmington, but we do know from the scorecard that there are six or seven sort of abnormally long holes, including two par fives over 630 yards on the back nine. Distance is going to matter. Irons are going to matter. And that's kind of a setup for Rory McElroy any time we get it. I also like Xander Schoffley this week. We don't probably don't really think of Xander as being a long hitter, but he's long enough. 60th percentile and driving distance gained over the past 50 rounds, which obviously is above average. And there's a difference between being short, being super long and being somewhere in the middle, you know, at or above average. And that's where Xander is. And that's totally fine because he's also got 85th percentile iron play. He's one of the best putters on the planet. He's going to vent grass as well. And he has three no-cut wins in his career on the PG Tour, plus a total score tour championship win, if you want to count that. So the high floor, the high ceiling from his good T-degree in play and putting through that all-around game is really what makes me understand out in no-cut events. I also like Max Homa this week. If you think of golfers who are long off the tee, have good irons and have good putting, it's a pretty narrow list because those are all three really great traits to have. But Homa fits that. He's got 76th percentile driving distance, a nice 69th percentile score in long-term iron play, 87th percentile in long-term putting. He won at Riviera in 2021, kind of proving he can do some damage in tough fields. And frankly, he's an upside player. He's one of seven golfers in this field to have an 80th percentile week or a spike week in tee to green play and at least 50% of his events over the past year and in 33% of his putting. So half the events tee to green, a third in putting and the other six golfers who fit those, they're all 27 to one or shorter. I like Homa as an outright, but also top 10 and top 20 as well for this week. That'll do it for my favorite bet for the BMW Championship. Best of luck this week. Let's hit a winner.


Would you like to know about other ways to make money aside from your normal job? You probably have hit a mental wall, trying to figure out different ways by which you can make more money. Thankfully, this article covers 30 ways by which you can make some extra cash aside from your normal full-time gig this year, as well as the requirements to get started with them. If you are an entrepreneur or an ambitious person, we especially invite you to join our Motivational Channel which was designed to give you daily inspirations so that you will have the strength to pursue and achieve your most important dreams. We call this channel Hunt TV, and you can join in the description box. 1. CV Resume and Cover Letter Writing The high competition on the few available jobs have made crafting and reviewing of CVs and cover letters a lucrative way to make money. With a few online courses, you can become a professional CV writer, and via freelance platforms such as Upwork, Guru, ETC, you can generate extra cash for yourself. 2. Blogging This is an exciting way to make extra money. It involves sharing personal experiences, latest trends, or news on your favorite niche. And after growing your viewers and subscribers to a particular number, you could be paid for ads to be posted on your blog. Sites like WordPress and Blogger are what you need to get started. 3. This is another exciting and entertaining way of blogging. Blogging could be done by creating a YouTube channel and posting videos on diverse or specific subjects. 4. Video Editing Video editing is used to arrange and present all video information, including films and TV shows and video ads. As the number of online interviews, skits, ads, ETC increases, the demand for video editors are on the rise as well. Software is like Adobe Premiere Pro and a few online courses can get you started. 5. Animation Animation making is one skill that won't be going out of the market soon. More so, there are now really cool websites and applications that allow you to create animations without prior knowledge of rigging and modeling. You could register on platforms like FIVAR, Guru, ETC, and create adverts and other animations for clients. 6. SEO Expert This is an individual who knows how the search engine optimization works and how to apply it to increase the relative placement of websites in search engines. It is no news that many businesses are looking for ways to get their businesses online. With a sound knowledge of SEO, you are sure to make cool cash. 7. WhatsApp Instagram Influencer These are people with high social media followers who get paid to post ads and are even made ambassadors of products to push and influence their followers into patronizing those companies and products. Well, now you know you can make good use of your WhatsApp and Instagram audience. 8. Storytelling and Content Creation The bedrock of every business is content writing. Over the years, storytelling has been seen as a vital way of making businesses known and driving sales. So the act of storytelling and content creation is very lucrative as business owners are looking for people who can write down the story of their brand. Good news is that websites like HubSpot, Skillshare, ETC offer professional courses to learn how to. 9. Copywriting This is the profession of writing copies and ads with the aim of advertising. A sales copy is written content with the intent to grow brand knowledge and eventually compel a person or a set of people to do a specific task. This is a hot cake in the freelance market because every business owner wants sales. 10. Forex Trading This is the prediction of the rise and fall of the foreign exchange currency price. The foreign exchange market is a globally distributed market for currency trade. For you to be a forex trader, you have to dedicate your time to in-depth learning on how the market works generally. With consistency, you will be able to make awesome cash from trading. However, it has its risks too. 11. Affiliate Associate Marketing This is a process by which an associate earns a commission for advertising another brand or company's products. All you the associate needs to do is search for a product you enjoy, then promote that product and receive a part of the profit from each sale made. Examples are Jumia Agents, VTU Agents, ETC. 12. Podcasting This is like an online radio where broadcasts are made available for download. All you need to get started is to select a niche and an application such as Speaker or Ankor. 13. Network Marketing This is called multilevel marketing MLM. It is a type of business where independent contractors invest in an organization and earn a brokerage on products being sold and also get benefits for referring other people into the business. This trade attracts a lot of people as they can be the boss of their own. Examples are skincare companies like Ori Flame, ETC. 14. Ghostwriting These are those people passionate about writing but are skeptical about publishing or don't want to have their names out in public. If you're on this table, you could tell your books, stories, to interested people and get paid. You, however, do not get to speak about writing sold works. 15. Social Media Marketing This involves organizing campaigns for brands on social media platforms to raise awareness or drive sales. With knowledge of Google tools, various social media platform tools and a few courses on HubSpot, you are good to go. 16. Social Media Management This is the process of designing, planning and posting content on various social media platforms for organizations and individuals who are too busy to do so. Just like social media marketing, all you need is knowledge and data. 17. Website Design This being very broad includes different sorts of skills and branches in the creation and maintenance of websites. You could choose to learn all or only the ones that interest you. Even with knowledge on certain ready-made websites using WordPress or Wix.com, you can make cool cash. 18. Software Development To earn from this, you must learn certain programming language. But that is not an issue because FreeCoded.com, W3Schools.com and a host of other websites are packed full with needed resources. 19. Graphics Design With knowledge about graphics creation from scratch or via applications like Canva, you can work remotely designing logos, mock-ups, etc. for individuals and brands. 20. Course Sales Platforms like Udemy and the likes have made it easier for the course sales market. You can create video courses in any field of your choice and upload on platforms where people pay to get them. 21. Investments This is the setting aside of a specific amount of money in anticipation of getting profit in return. Investments can either be long term or short term, depending on your choice. 22. UI Design User interconnection engineering is the design of user interconnection for machines such as computers, home appliances, mobile devices and other electronic devices and also for software to make usage easy. 23. Online Consultancy You can use your expertise in your field to consult for and coach people remotely. It is an exceptionally lucrative side income source for those who are practically oriented, especially those in the medical field. On freelance platforms like FIVAR, you could consult for people across the globe. 24. Public Speaking This has to do with rendering a speech to a live audience on a particular subject. You could start as a volunteer speaker or sell your skills on social media. Just like many other skills, public speaking can be learned. 25. Mini-Importation This is when a person imports in small scales at a very low price and sells at a higher price. The only thing you need to do is reach out to companies that sell cheaper stuff. Thankfully, there are various online classes on how this works. 26. Ship Dropping This is a supply chain management method in which the retailer doesn't keep goods in stock but instead transfers its customers' orders and shipments particulars to either the producer or another retailer who then ships the products to the customer. All you need to get started is a few contacts of foreign producers or retailers. 27. Typing It is the process of writing or entering text by pressing keys on a typewriter or computer devices. This can also be done as a side hustle and knowledge about Microsoft packages is usually a plus. 28. Translating In order for you to earn via translating, you have to be proficient in more than one language. Many website owners are looking for those who can translate their websites for them as they look forward to going global. Translators work on freelance platforms. 29. Editing Tons of good writers are searching for people to help them edit and proofread their manuscripts for a fee. With a sound background in the language required and a few courses from EDX or Corsair, you can make money. 30. Webinar Hosting Maybe you are an HR personnel or a project manager or a photographer or even a high school teacher. This is a lucrative way to make money. You can host paid classes based on your area of expertise on WhatsApp, Facebook and other media platforms to teach people. Don't forget to always develop a passion for whatever you venture into. Your passion to any scheme is directly proportional to how much you will make out of it. And just before you go, watch other videos on YouTube. If you are an entrepreneur or an ambitious person, we invite you to join our motivational channel. The objective of the channel is to give you daily inspirations so that you will have the strength to pursue and achieve your most important dreams. We call this channel Hunt TV and you can join in the description box. We love you.