I have been following the entire IDAC on YouTube since morning, probably. So one request to everyone over here is because the only comment on YouTube throughout the day which was common, not audible. So it's a request to everyone, please keep the mics as close as possible so that at least everybody can listen all the insightful things that we're going to share now. So a lot of us in the panel come from the real good old days of advertising and digital marketing when digital was starting in the country. Me and Manas have worked very closely almost for 15 plus years now. And today we are sitting in the same forum discussing the role of independent agencies as we call it challenger agencies, how we are shaping the entire landscape of digital media or rather advertising as per say. So as the introduction has already happened, I would want to first thing first go to Dev and understand how the data, the first party, second party, third party data is going to impact us. Most of the clients today talk about conversions and how the data is going to affect us. Dev, would you like? Yeah, sure. So I hope I'm audible. So the way I am looking at it is, you know, obviously there is a huge amount of UN cry about third party data and the amount of data that gets in the hands of publishers. And I think to a large extent it's quite a reasonable concern that a lot of people have. The only thing is that there's enough and more that's happening to build an alternate way of identifying or creating cohorts of behaviors, I would say, without sharing any personal information. So there's so much that is happening, whether it is through universal IDs that a lot of, you know, independent partners are building, whether it is through really focusing on building first party data that a lot of brands have started doing, which is whether it is through their own D2C website, whether it is through communities. All of that is also happening in a very big way. Or I was reading this strategy around contextual targeting, which, you know, obviously a lot of us do rather than talking to actual users or specific users, I would say you end up talking to cohorts who are reading or consuming a certain kind of content. So there are ways in which I think the two things can happen. It is not that efficient targeting means that you have to necessarily know everything about a user and capture a lot of private information about them that they may not want to share. But there could be a workaround that has started emerging. So I think in the long term, this will probably be a more effective way of meeting both ends, essentially. That's my sense. I guess. Wonderfully said. However, a minus I would want definitely your two cents on this. The data deprecation as I know you come from hardcore media background, right? From Samsung days to today, whatever you are doing. Plus, you handle one of the most demanding performance clients as I know. So as per you, how difficult it's going to become. Can you just guide us because we are also agencies, right? We would want to understand how to address this. The performance, how the performance will get affected because of the data deprecation, the first party data. We all understand what happened to media maps, right? When you talk about data, we were having a session just next door. And what we were talking about is at times we overanalyze data. And we talk about digital being a measurable medium, which is why many a times, if 50 lakhs are spent, it becomes 5 lakhs. Whatever is measured, it costs. And we also know historically back in the day that TV se koi koi question pujta nahi tha. And when we start overanalyzing things, then the pie goes smaller. While it's solving the same purpose, probably giving you a better customer through precise targeting. When we do it on digital, but because of the fact that we tell them that we can have real time reporting, probably it will attribute through view through conversions for the final performance and everything else also. So many a times, the pie gets smaller. While it is doing a better service than probably a TV advertising would be doing and probably giving you a better audience through CTV advertising. Still, we are the ones who are deselling our own products to the customers also at times. And it has to be, when we look at the entire consumer journey also, the whole world talks about awareness, so we have to do TV and do something else. So the strategy should be that in the entire AIDA model, which is awareness, interest, desire, action, and using those customers for talking about your own products also. In the entire journey, we should talk about the entire journey rather than only conversions most of the times because there is a certain cycle to the brand as well. You know an established brand probably like a Bajaj and HDFC who already has a great brand salience, their brand plus generic keywords are well known in the outside industry very well. They probably don't need that amount of awareness indexing and everything else, which is attached to it. While in the current set of things where so many investors have invested in say new startups and everything, they are the ones who actually need a lot of awareness indexing, a lot of buying and also creation of first party data over a period of time to reach a certain situation where they can only bank on performance. But till that time, there is an important need to spend a lot of money on awareness, reaching the right set of customers, getting high on the consideration set also. And in situations where you do not have as much budgets to probably do awareness indexing, you have to rely on the category and the competition to create that category and you need to bank on that for your own products. Thank you. That was very insightful. So you just used the keyword while addressing the situation, CTV. We all understand connected TVs. Probably I had my first smart TV back in 16 or 17, but we never used to call it CTV those days. So Shraddha, would you like to throw some lights on how the connected TVs are playing or what role are they playing in today's media landscape and how digital agencies can embrace that instead of just using it as a jargon or a keyword, but actual utility in our media mixes? Yeah, better. So I'll start with a small anecdote. Today if you look at CTVs or connected TVs, we are only 25 million as per the last stats, right? It's not huge given the fact that we are 700 million as an internet audience. But the best part is the decisions for any marketing plan are taken. Hello. It's that. It's that. Hello. It's gone again. So the discussions happened in boardrooms. Now I was sitting with an FD of a renowned brand who is the largest in its category and when we were doing this discussion, he was like, I have stopped watching TV. I only watch Netflix and Amazon. Do you watch it? Mr. Sharma, do you watch it? That's where the discussion genuinely starts, right? It's not difficult to sell connected TV in a boardroom still despite the number is 25 million. But it's also a great platform for you to now see what this can bring in terms of innovation, precise targeting, better placements, right? Because you can only say that I want to target somebody who's watching a new horror category or fashion category. Bach is a sample plan, right? On TV, it is on a sample set. But here you have exact data.  But at the end of the day, still it's better than the TV that is going on there, right? So I think from the perspective of future, from the perspective of MDs and CEOs, it's a great platform to advertise on. The next thing which I think connected TV can bring in is a lot of lower funnel and mid funnel as well. I am watching a show and what happens is, let's say I'm watching Night Manager and my husband will be like, I like this girl. Yeah, let me just tell you a little more details about it. Here's the name of it and then we'll go to Wikipedia and search her age and other stuff about her. But what we don't realize is it's not just about the girl or the boy that you're watching on the TV, but you can also actually see the product that they're using, right? You can actually see that, okay, if this is the product that you're watching, is there a way of knowing more about this place or product? Can I buy it? So there's a lot of integration for this audience on connected TV which you don't find in your regular TV. So it's more two ways. I might also have a survey which says, did you like the project that I was watching? We had Netflix and Ranveer Singh which was wild and something where we have interactivity. We could change the cost of what we're watching, right? So that was, I think it has a great future and would be helpful in terms of driving more two-way communication. Thank you. So that was pure play media insights given to us from Shraddha. But again, I derive another keyword over here. So I think I would want to ask Ranjeet over here. So on connected TVs, as very clearly mentioned, it's still a TV but measurable, right? That's how I can zero on, right? But as it is measurable, so just because we are seeing the technology is evolving every day, even on TVs, right? Sony, LG bringing something new every day. So can we say in future, the journey can be completed, the consumer journey on connected TV from seeing an earth to completing a transaction within the TV frame and not moving to another device? Is it possible or is that innovation which is going to take over this entire journey or is it the creatively we're going to entice the customer to complete the purchase cycle within the TV ecosystem or the connected TV ecosystem? So I think the one important part of connected TV is that the TV in its own form, which used to be a social experience at home, is slowly giving way to a personal TV. So like your personal mobile phone, most houses today have two, three TVs. And so it's a personal TV for them. Your question actually is that in a social experiment, in a social setting, shopping, if you're watching a soap with your family together, kids and stuff, may not be the right, I would say, thing to solve also. But when you have a personal TV, like my daughter today would watch her show on her own TV and would actually go back and search those stuff that she's watching on a mobile phone. Like, I mean, what you're saying, that how can you bridge the gap between that experience of shopping or exploration between those two devices. In fact, there are certain applications in the US who are trying to solve that.  So I think those things are there. Amazon has tried with Alexa and Alexa TV also. So yes, I mean, in future you'll be able to shop off TV, but it will be equal to a personal experience, not a social experience or to say at home. I agree, shopping has always been a personal experience for all of us. Yeah, I'll try and answer that and disintegrate into two parts. So at home, there are multiple devices and devices are connected. And I was also in a closed room session there and this question was asked. So if you put, say, a coupon code or something there, it's a 20-seconder which goes there. And by the time you probably take something out to purchase something and do the entire process, those 20 seconds are gone. But the IP addresses are captured. So the system understands that these are the IPs from where an entire family is probably connecting and they might have witnessed a certain ad. So for me to attribute to that specific ad, I can target the device which is running on the same Wi-Fi and an IP. That's where my entire journey probably can be completed from a screen, which is a smart screen, coming back to my phone and the system knows the frequency at which it is being served, probably showing it in that ecosystem again, might continue that journey and eventually culminate into a purchase pattern which can happen. And this is also an integration probably of a couple of things. There are some products like Silverpush had a product that if you're seeing something on TV, you can probably target them on your mobile phone. And what CTV is providing you an entire ecosystem that you can do that along with this and then culminate into an action later on. So those twin-screen problem, I think it's solved there. Pretty bang-on, I would say. Both the answers, Ranjit, what the example of Amazon Echo was bang-on. And I don't have the numbers right now, but I was going through this study back in the U.S. is happening. The majority of the list shopping, as we call it, the regular groceries are done through Amazon Echo now. People just while moving to the office tell the Echo that, okay, please arrange all these stocks for me when I'm back. And actually it is happening. And what Manu said, for non-grocery shops, which may be a mobile phone or anything which is of larger purchase value, probably a connected experience is more important than a connected TV alone. So a follow-through communication from our TV to the same IP mobile address because once we are home, we are all connected to the same Wi-Fi and we cannot deny that. So yes, I think both the answers are bang-on and we both, or rather we all are aligned to that. Now coming on another challenge that all the agencies, the challenger brands or the independent agencies as we all are face is the content part. So if we look at the pitches that we all make, the pitches were pitches and still are the same pitches which are driven by ideas followed by great creatives, some out-of-the-line rational to explain those ideas and creatives and then coupled with great media integration ideas, everything, right? But from top to bottom, we see content being part of everything from an idea stage to the campaign stage to the media stage. So we are living in the content economy. The content creators are probably having bigger top-lines than us. So how relevant the content is today for any pitch, is it? That you have to have a content creator only to win the pitch or without a content creator? Micro, macro, influencers, I don't know. So I think you can answer me, Mr. Mehta. Yeah, so I just want to first double-check on the question but the next session is by Prajakta Kohli. So I think while we speak about top-lines I think we will have her as a benchmark, the way that how individual brands have probably gone above the roof and have actually nailed the entire market. Now there's a word that's roaming around. They are calling it single-person unicorn. Oh, is it? Yeah. Mr. Beast is moving in that direction. Logan Paul, he is. He is that way. So we really feel that while the entire economy is taking its shape, right? I really don't see this not happening that there are going to be maybe single-person unicorns or people with 100 million following just creating content in Marathi. So the population of Marashtra would be, I think, 90-nought crores or something like that. So I really feel that if at all there is a channel like Mr. Beast, right? That's probably 10 crores right now and it's growing like anything. So I feel speaking about creators, that's a very sound arena where now a lot of agencies are trying to figure out how to capture that market, how to probably have something in the intersection of content, XROI, X creators. But I want to understand the question. So what you said is right. But my point was, see, we are looking at, we are independent agencies, but today we see even creators are getting cartilized. They're part of larger celebrity management groups. The cost of a creator has skyrocketed, right? So for me to buy a television artist to endorse my product, whether we are creators, TV artists are coming cheap today for me. Trust me, right? I cannot comment on the efficacy of both, right? Who is going to create a bigger hype for me? Probably if my product is for Gen Z. If I'm selling a real me air bud, probably. A creator might work better, but if I'm selling an FMCG product, a TV seller will still work for me more, right? But this is the constant debate that will continue. My only point is in the current age, like, times recently entered the creator business, right? The creators, which as an agency, I might be paying 100,000. Today I have been requested to pay 500,000 for the same. My clients question this, right? So as we are sitting on this forum, how to address this question? That's my point is. Or shall I go with micro, macro, instead of the bigger A-listers? What is that? So I think there's a technical answer to it. I'd want to touch upon that. But before that, just a little bit of context around what we guys do. Maybe that question is relatively more relevant to the work that we guys are into. So we are this influencer platform that's predominantly in the vernac space. We pivoted into now a SaaS that's supporting marketing agencies, create their own communities of influencers and brands via a full-fledged tech experience. More on this later, but the fact that right now the entire age is so much to do with going hyper niche, hyper-local. If at all you have an influencer that is relatively wider in terms of their reach, versus if you get influencer who are hyper niche, so we call it the 6R theory in culture X.  The first aspect of it is reach, of course, which is their fandom. Second is so much to do with the kind of resonance that they have, the category that they lie in. The third R is so much to do with the largely reputation that they hold, what kind of background that they have. Somebody like Ranveer Kapoor will have a relatively sound reputation versus somebody who's just starting out as an actor walking in Bihar. So that's another R. Then it's so much to do with region. We are all speaking about vernacular and stuff like that. We are speaking about then the relevance of that influencer, what category he comes from. Then we are speaking about the, of course, ROI aspect, the rates of that particular influencer. So it is reach, resonance, relevance, reputation, region, and then we speak about the rates of that particular influencer. So there's like a small science around... Probably we have to add those pointers in our next pitches. Do give those, all the Rs. We want those Rs. from you. You know, I think one thing on this is you asked about whom to use. Exactly. A larger question. So, you know, purely from a personal experience of talking to clients and investing in something you're saying. So, client today, and at least many of us are here, client today want, first of all, first, a creator-led content. It does not need to be influencer. It could be a creator, which is a resident, or you get a content creator. So, influence comes later. How can we do creator content itself? Thus, I mean, in our experience, clients like Swiggy and tons of them really today, we have put a full-fledged soundproof studio just to create content for... So, the demand from the client today is to first, you know, all those graphics and stock to... All that to have authentic content, which are creator-led content. And I think one very important change that influencers have brought in is to show the brands and agencies the possibilities, right? I mean, today a homemaker can create as good a content as the agency can create, right? So, it's very important that the benchmarks are there. Now, agencies today have to first match to the content quality of a creator. That's one. And then, you know, in order to... So, if a brand is a D2C or brand is a long-tail brand, we have worked with Mama from day one of their time. We have seen that early brands are built on volume, not on one of or two of things.  But smaller brands, we're tying up with mid-tier influencers, but for longer time, so that the impact on that... But first is a creator-like content. Depending on size of the brand, you can look at a long-term perspective or a campaign-specific big name. And, you know, I think important is that whom you are serving, generally creator-like content is very, very important today. Just one thing to add, while an agency has to see the content creation space, right, they have to see themselves as a mutual fund for IGC, that is influence generated content. The debate is so, I think earlier we had sessions where we had Herschel speaking that if it is AI versus HI, Human Intelligence versus Artificial Intelligence, he made a specific slide to cut verses to and. So now it's not AI versus HI, it's AI and HI. In a similar fashion, is it a macro-influencer or a micro-influencer? No, I really think that we'll have to pick in a very diversified fashion that you'll have to have some macro-influencer to add up to the credibility of the campaign and then based on the XR, like 6R theory or something like that, or maybe based on some sort of relevance or your set of individual agency signs, just bifurcate in hyper-local categories too. So just choosing one I think could be a very I would say very loud approach which can also fall back so that's one way I would want agencies to see. So I'll just add an angle of, you know how it pans out. I'll just quote an example so back in the day, two years back we were doing a campaign for outfit 7, Talking Tom and Friends and we were providing app downloads and in-app actions later on and this we were doing with content which the brand had provided and we first, you know, went back to them and said that why don't we use an influencer, why don't we use Shilpa Shetty and because she has kids also so it's contextually relevant and maybe it has a better effect and we were getting a cost for download of 12 rupees and when we used Shilpa Shetty we started getting the same download for one and a half rupees so there is definitely an influence which was created it might vary by category as well and if you look at the current, the way it's spanning out for Facebook and Google they are coming back and saying why don't we do branded content with influencers so that the ROI the click-through rates, the engagement rates, all of those are going up and that in a larger scheme of things it should be tried and tested and not taken on face value it might work with certain influencers who are contextually relevant but having a random list of people who have influence overall, I don't think so that's the way to go about it and to the second question there is a certain way the influencers need to be used so there would be certain film stars certain cat-a influencers cat-b influencers and cat below that as well, cat-c also so one might be for creation of reach, one might be for creation of influence of quality followers and the third would be as an overall awareness perspective as well so each of them solves a different purpose and if it can be tracked back to the final attribution if that's in place in India and everywhere else also while we talk about the journeys and everything but people judge you on the last attribution for sure but if that's in place then I think the entire scheme will work and the clients will also understand overall I just like to add one more thing here I think you know what happens is it's more like branded content versus content that's being put together by another individual that's really what this is about not so much about macro-macro in my opinion because you know I think all of them are quite effective and in that train I think social proofing could be just as effective which means I don't even know who's saying what I mean who is this person and this person is just a regular consumer regular mom or regular whoever who's the consumer but he or she brings in an additional social proof by saying listen I use this product and it works very well for me and that itself can have a huge amount of value at times sometimes even more than an influencer because people now know that an influencer is being paid but a proper organic review can have a far more impact as well so I think it's and from a larger brand perspective it's also about building that balance you know so you don't want your feet to look like it is just a lot of people talking about products without any real product the brand so to say how's being created so it's I think it's a little bit of a mix and match that you need to do so that the branded content and you know content by people can coexist together perfect I cannot differ on that and Ranjit what you just added sometime back I totally agree it's a bang on theory that brands need creators more than influencers I can recollect that because one of the real estate clients that we were handling we went ahead and did a campaign with bloggers on YouTube who talk about only real estate in that particular market their followers were hardly 1300, 2000, 5000 they started reviewing the project and the bookings skyrocketed the content was mediocre the equipments used was super mediocre but the context was most relevant I believe instead of going glamzy and glittery and promising like a a-lister these were young people in their 20s and they were reviewing the real estate the product, the flat, the quality and because they were in this space of real estate review and it worked so yes now I can relate what you said and even Manas added a lot of the last attribution model is required for sure the collective approach so another point is starting from here because as we collaborate and partner with a lot of publishers influencers probably within the agency scope we have certain agencies like culture X who is servicing agencies as well as clients probably so in terms of partnership and collaboration like larger global group agencies from WPPs, Omnicoms or LBI's of the world the independent agencies what is the edge that we have which can be the right mix because we won't partner together probably we may partner with culture X let's accept the reality right because if we will partner the world will call it a merger that these two identities are merging together the collective revenues and everything probably but we may not partner on a project until unless client says that X agency handles my social, Y handles my media please go ahead and create this campaign together otherwise we may not go together as a collective effort for a pitch to win a client so as an independent agency what is that one X factor that keeps us ahead as for you guys we are all survivors of this apocalyptic world of independent agencies where we were bitten by this bug back 14 sorry 5-7 years ago probably so please somebody anyone can help us you know we actually are sitting together and we work together on the same plan so he and me work on Bami Boko Pants together right and we meeting for the first time but and you use the word when we started the whole panel was challenger we are just challenger we are hungry also and it's survival of the fittest also because right that many agencies have come in the same road like in the area where I have my office I was the only one 5 years back now there are 4 more agencies in my lane itself right the problem is the entrant to business is zilch now that's the problem now in this whole space where survival of the fittest is we are cutting the cost madly he is saying that we are spalling the market by telling them too much measurement matrix we are also cutting down the cost to drive that business and get that business back and now if we have to work together there will always be an angle being a human that why don't I get that business instead of the other person getting that business it's very difficult for 2 people of the same rank it's like 2 students in the same class trying to work together that business out but in group agencies where you know the client will not give the mandate of a particular service to another agency you do that like in Panasonic I am working with a Denso I am working with Mediacom where we all have our individual roles clearly defined and we can't merge so we know that no matter how hard we try we will not be able to get that part of the business or pie of the business so that's working very well but the reason why there is no independent agency versus a group agency is pure hunger as well as the attention that they are ready to give to that client today if you look at a group M and I am no offense to anybody from group M sitting here but no offense but the kind of time and attention a group M employee will give versus a founder driven agency will give to a client depending on their budget is way apart and that's what first of all drives them to us second is consistently good work so if you've been their right hand like we say that one of the key things that we define us as is we are your chote not chotu chote is basically who will go and murder for you also not the chotu who will bring your food so if you are the chote of the client then you are basically their right hand who is saying that I have already told you your problem whether it is a brand problem or business problem we will figure out a solution for you we will not say please send me the brief over an email and then we will get back to you in a week so the ownership that we have towards our clientele is way different which in a country like India which is not planned every brief was to be delivered yesterday not tomorrow that's where I think independent agencies to be very honest have been really successful and then the third thing comes the pitch that you were saying if you had a great pitch you did a better idea you genuinely was able to crack that moment at that time of the day you are home so these are three big reasons I think independent agencies still get this I have one point to her point really I wanted to say that thank you so much we have it has become the relationship very toxic no yeah so I think what you said is right that they come to us but I tell you on our partnership I will just take a minute because we are an 11 years old company and we couldn't have been here without partnerships I think I met couple of folks here also why Optima and couple of folks with whom we have worked long long back so I think I tell you partnerships are very important when both the party are not insecure about each other right and if you have those partnerships retain those partnerships so we are partnerships you have production partners production partners are working 7-8 years it's important to have a say a boundary that this is what you are doing this is what you are doing and most partners will not eat into your business because they know that if I have to work long time then the kind of relationship I was mentioning that we are younger that they cannot go beyond us we are solving them the partner is not solving the problem so as long as they are dependent on us for their solution any partner you bring any partner is sensible and long term part you know I mean long term thinking then partnership works in fact today post 11 years about 10 odd employees of ours have started their own company small agency or production house XYZ we still work with them actually so insecurity goes side make and have boundaries and have long term view you can have long term partnerships also and without partnerships independence it cannot grow because you can't have everything in one one yeah Ranjeet I am sad that you forgot our collab we have just collaborated we have I mean like he said that of course our collaboration is anyway we have to end up with culture X also I mean and I'm meeting first day yeah yeah so yes I have a metaphor to what you are saying I would want the group I would probably consider the group companies as the elephants one who are as hungrier than as hungrier like us right I call us like the wolves of the marketing street and then like probably so maybe culture X that way is not the wolf but we probably are trying to set the jungle right so by the way the collab that you guys are speaking about right is also collab that we thought that somebody will have it for us while we were like a marketing agency or like maybe we were trying to create a marketplace of our own and the moment you are not able to get that we raised capital and we were like we are going to be the one who will actually partner with a lot of other agencies and give them that environment to actually build something on top of it but yeah I think interesting point yeah thanks I'd like to add one more thing from a collaboration we were actually just discussing this before we ended on stage right we only talk about collaboration to drive revenue whereas we are not talking about collaboration to make the industry better right somewhere at the end of the day let's say I will not take a name of client who has not paid me for 6 months now what will he do he will just go to another agency and say that you know I have my pitch open why don't you come over and pitch me it's a big brand name nobody knows what happens with the finance department but I can pick up a phone on let's say Dave and Manus I know them well beforehand right I can pick up a phone on them and say that this is what happened with me on this agency I am an ex-interactive right so I genuinely pick up a phone on you know Rahul who's now moved for a sense or Abhishek like you know what happened with that client do you think it's worth pitching them what are the challenges when you face working with that client because today getting a business is not difficult there's enough and more business in the market the challenge is to retain them and maintain that relationship it's very difficult so we need to collaborate beyond just getting business we need to collaborate at a level of whether this client is right whether this rules and regulation is right whether this employee is right it's become a one-way street with employees today they can bash you anywhere but you are nowhere to talk about how that employee drove ownership within your organization so there has to be a lot more collaboration to date together for example in Delhi I have another friend who's running another company I knew the account was not coming to me and because I have another exclusivity with another client so I called him I said you know what here's a client I'm going in your contact why don't you pitch there's another small agency that I have I will not pick a retainer of a particular size so I pick up the phone on him and say you know what I'm not picking up this retainer I know this client very well let me recommend you and you guys get that business so I think collaboration has to go way beyond what we think today it is wonderful you put I have three instances to mention sorry I may just bore you a bit the first is what you said earlier about the toxicity of the relationship although you did not Ranjit said but you kind of endorsed it right that at the challenger agency I'm calling it toxic I think because we kind of service clients above and beyond than a global agency that's right I'll tell you a small case in 1819 a client which was working with ARM called me right and called me and they said like we want you to guys to come and fetch and meet me and we want you guys to take the account I was aware that they were the clients of ARM I immediately asked but you guys were working with ARM what happened no we are not happy with them I said then I cannot make you happy either I honestly said that because all the three people or four people of ARM are all good friends and we know each other for more than 15 years and we have grown together in this industry and I cannot do anything extra to help them or make a please them a God knows what and I said it straight over the phone that I'm sorry if they cannot make you feel better or happy even I can't that was the first instance second you said about the pitches the best day the best attempt the best effort the best idea wins you the game another thing so we started a small we bootstrapped we were in a thousand square feet office moved to four thousand twelve thousand square feet slowly gradually right the furniture was bad second hand to the swanky nice everything happens over time so there was this pitch we won it was a new mobile phone entering the market the CMO was from an existing mobile brand we won the pitch everything wonderful the CMO decides to come to our office we were a midsize office back then he comes to our office for a coffee he sits with us he goes back he says we can't give you the account I said why he said no I think Ogilvy is better I said no Ogilvy is best I can't question that but we are talking about this pitch we were better you only said during the pitch he said no no I think you cannot handle the load I just saw your infrastructure so just because we were a midsize midsize challenger brand or smaller agency they clearly said I think your infra is not adequate enough to handle us and we could not debate that the third point which was again beautifully said by Shraddha collaboration has to go beyond business one of my clients did not pay me later on filed for bankruptcy and these were media monies not the retainer monies which I could have written off I had to pay back to all publishers from my own pocket slowly gradually eventually yes I paid off everything I think Idaq is the first edition of Idaq and I possibly am very happy if you can come up with another idea which can create a collaboration sort of body for us which can act a kind of a referendum or sort of a charter which at least hygiene charter which we all can follow and another hundreds of young agencies who are coming up a knowledge sharing platform about clients about even manpower which is the biggest problem with us I think the world will be a better place thank you so much everyone this is working now Google has paid some billion dollars to government right now just because they moved some policy here there couldn't they pay for your bills I mean somewhere Idaq should figure out a way that somebody is making so much I remember five years back I was billing 3D 360 through Singapore entity of Google right and there is something called a equilabitax and I don't manage taxes that's something that my another partner manages and I'm sorry this is honesty on this forum and they asked me to pay it and I had not charged that to my client and I was arm twisted that my account will be shut and for that for a year begged in front of them sir we are small we are a challenger brand do something like everything like everything but nothing worked we had to pay that money from the revenue we made from that year and that's the challenge that you are facing that commission don't even talk about what we are on you know we are challenger brand we don't earn we have all burnt our fingers 7, 8, 10 years of our existence luckily we survived the pandemic trust me most of my peers that I know from the industry started their shop have shut down we survived we were strong enough to survive so I think IDAC should take out more initiatives anybody can add any valuable inputs about it I'm more than happy I have a question I think to put a few guys and I think this is very important because this is something that the topic was that the times are evolving how can the independent agencies solve upon what are the existing challenges you guys almost have decades of experience I think we must give it to E4M to actually solve this I think they are the ones who can solve for us by having a forum like that maybe interact and so on so forth when I have the snack of always asking questions the moderation opportunity will come soon no I just wanted to probably touch upon these things maybe one of them could probably answer that question would you like to pick it up my question just was that if you guys have to go back maybe tens of years of experience and if you guys have to probably give one piece of advice with whatever you guys have achieved in almost a decade that right because there are also going to be a lot of emerging agencies which can actually benefit out of your decades of experience right what is that one piece of advice and if you could do something differently maybe touch upon that please a little bit these are like very intense questions but could we have one of you answer would you like to try and answer that to the youngest 10 years back I would have wanted to say no more saying a yes on some of the things which the client said and probably should have the wherewithal and the hard work with all the hard work which we have put in I think have a larger repository of TGA and target audience and brands to work with so that you can with full confidence say no to people who are unreasonable and from a pedigree standpoint while E4MS provided a brilliant forum for all of us agencies are not recognised as much you know you might want the client to be here and talk about it but the nitty gritty of each of the services which are there we all have gone through the entire process and we know all of that as well so to the younger self of course I would market myself so much so that I have the ability to say no at a certain price or to something which is unreasonable over a period of time I think which is why we have survived because we don't sell cheap also well put Interesting interesting take well with that let's humbly thank our panellists with a big round of applause for sharing their knowledge


So, uh, I like wearing Spider-Man clothes. If you looked in my closet you would see so many spidey hoodies and outfits that I'm honestly ashamed to admit that I would struggle to look in my closet and find clothes that actually don't resemble Spider-Man in any way. But naturally, that just means I'm familiar enough with all kinds of Spider-Man clothing and merchandise enough to where I can make a YouTube video about it. So here we are. So there's like two types of Spider-Man shirts and only one of them is really interesting to me. There's shirts with Spider-Man on them and then there's shirts that try to make you look like Spider-Man.   If I could just be Spider-Man instead. What do I have to lose? My social credibility?   I'm Spider-Man! Okay, maybe not this shirt.  Like this is just a shirt with Spider-Man's chest piece ripped off and slapped on. That's not good enough.  If you want, you can just wear the shirt with the Spider logo on it. These are definitely more of a low effort choice and on the bright side, less people will look at you funny for wearing these in public.  With these, it really just depends on what kind of Spider logo you like. I don't like this particular Spider logo because I think it's too long and oddly shaped. I'm just, I know some people might like it. I'm just, I don't, I didn't write out why I don't like it in the script, so I can't go in depth. I just don't like it. I think logos like these work on places like the Tasm suit because it has the longer midsection to go along with it. But when you sort of just put it out naked on the suit like this, it sort of looks weird. It's long and awkward. And the Tasm logo looks way cooler anyway, so you might as well have just used that one.  I think logos that fit a more squarish even shape on the chest usually work well whenever put on a shirt.   You'd be surprised as to how easily accessible getting your hands on a wide selection of Spider Man cosplay hoodies are. I own a couple of cool ones myself, and I'll do a little, a little fashion haul and show you. Man, I have a, I have a lot more of those shirts than I thought I would. That's not even the last of it either.   And all you have to do is get your hands on some puff paint or a thick Sharpie, and you can really turn anything into a Spider Man hoodie. Here is my favorite hoodie of all time. It's just your average red hoodie, but it's got this faded spray paint-esque design with a spider logo on it. Or what about my black suit turtleneck hoodie? I only wear this one every now and then, but I like it a lot. But fine, fine.  Then I'll take you to the holy grail of Spider Man hoodies. This isn't your average printed shit, or anything you could replicate at home. These hoodies have embroidered Spider logos, hoods that zip up into Spider Man masks.  And they cost about $50 a pop in your heyday. But anyway, here is the classic Spider Man hoodie. This jacket is almost entirely based off of Todd McFarlane's artwork, which makes it even better. It's pretty much spot on, aside from the front spider missing the rounder legs, but it still looks amazing.  I got this hoodie a couple of years ago, and I still throw it on every now and then.  It's okay, I guess. They also did a Tasm 2 version with detailed printed fabric.  These logos are all incorrectly sized compared to the actual Tasm suit, and the lenses on the hood look way more ridiculous than they did on the last one. I've seen this hoodie in public without the lame mask hood. I think it looks good casually. But then again, you know, I'm here to be hypercritical about the design. So, casually, I think it's a cool hoodie, but it does not hold up under scrutiny.  Children! If you thought the Spider-Man hoodies before were insane, these kids' clothing items are even crazier! Like, bro, look at this kid!  Not only does he have a Spider-Man hoodie, but the pants on top of that!  Damn!  Would I wear this if I could get this in my size?   All right, but let's talk about something even cooler that you can wear as an adult. This is Super X. This is one of the coolest clothing companies that I have ever seen in my whole life.   I want the whole outfit. I don't want just the hoodie. I want the whole outfit. Look at it. It's like a combination between the color block, fashion trend, and superheroes.    I want one of these so bad.  Look at it. It's got lines and paneling all over it. It's over-designed. It's over-designed. I don't care. I don't care if I put this on, go out in public.   I don't even have any critical assessment to give you. This is no longer a video where I'm basing words off of a script that I've pre-written. I'm flying off the handle.  I'm done with this video. Hello. We're here in the title card, or the end card, rather. If you want, I livestream every Friday where you can check out my streams. I'll be working on my Spider-Man show, which I'm still working on. And if you become a member to the channel, you can get all access to previous live streams that I've done that are stored away for members only, and you can have hours. I'm literally not kidding, hours and hours and hours of PSM content. So if you want more of me, become a member of the channel, literally any tier, and you can get access to all my vods for your membership subscription. And if you only want one, you can cancel it anytime, whatever. Thank you all so much for watching. And if you want to hang out with me anytime soon, come see me on Friday, where I'll be live streaming. I usually start at about 8 a.m. anytime after that on a Friday, 8 a.m. EST.


Today's lecture what we will do is we will look at another application where we can possibly get a simplified solution for fluid flow problem okay and the idea is we are not going to be doing stability analysis. We just have to get a solution now to a problem which where we can exploit the presence of different length scales. So this particular problem is going to be called a shallow cavity flow. So as far as shallow cavity flow is concerned, first of all order exactly is a cavity, just think of a rectangular channel okay and let us say there is a top plate which is moving with a particular velocity u0 okay. So there is a fluid which is confined here and this is the rectangular channel and let us say as always it is extending to infinity outside the plane of the board. So we are looking at the story in this 2 dimensional plane okay, so no variations in the direction perpendicular to the board. So what we expect is that the liquid is going to be dragged by the top wall and it is going to circulate, definitely can penetrate the wall. So you have this kind of a situation, so actually this is a very classic problem. This problem is called the lid driven cavity and this is one of the first problems people solve in computational fluid dynamics. So you write down the equation of continuity, equation of momentum in x and y directions and then you solve using some numerical method okay. So this flow field is obtained using computational fluid dynamics okay. So the question of course is whether we can actually make some kind of a simplification and get some idea about the flow field okay and under some conditions. So when you talk about a shallow cavity, we are talking about a cavity whose depth, let us say this is the z direction and this is the x direction and let us say the extent in the z direction is d that is this distance and the extent in the x direction is l okay. So if d by l is very much smaller than 1 okay and we have a shallow cavity. What we would like to do is analyze this problem and see if we can get some idea about the flow field inside okay by exploiting this factor d by l being very much less than 1. Now where is this important? So for example you can have thin films okay or you can have maybe even microfluidic devices. So supposing you have a very thin film of liquid on a solid surface and either the lower surface is moving and the upper surface exposed to atmosphere okay you would have a situation where this is a thin film and that is the direction which is being dragged for example. And this of course instead of a solid solid wall you will have a solid gas wall but again the business of these 2 lens scales is going to be present and so basically the presence of these lens scales d by l being very much less than 1 d by l is a small parameter you can think of already an epsilon coming up here and how I can possibly use this epsilon force simplifying equations and getting some insight that is the idea okay. And microfluidic devices for example we long back spoke about something called a slug flow and the basic idea in a slug flow situation is supposing you have a 2 phase flow and let us say this is oil and this is water you would have things like oil slugs almost occupying the entire channel okay, separated by water. So what is going to happen the oil is going to be flowing okay and this is going to be continuous stream of oil drops or oil slugs flowing and of course there is also water present here which is also flowing. Again if you do what we did yesterday that is work in a moving reference frame that is you are sitting on the oil drop and moving along with it. It would be like the oil is stationary and the wall is moving backwards okay sitting the water occupied portion and moving again the wall is actually moving backwards. So what you can see is when you have this kind of a relative motion between the wall and this you are going to have internal circulations inside the slug okay. In the moving reference frame we have let us say we forget about the film this guy is moving backwards. So this is something like your lid driven cavity problem okay. Only thing is instead of solid walls I have a liquid-liquid interface and it is approximating this to this okay and what I am going to observe is I will have some kind of a flow pattern of that kind and a flow pattern of that kind here. So some vortices are induced okay. So the point I am trying to make here is when you have this kind of a slug flow regime you would have because of the viscosity you would have vortices induced okay and the one way to understand this is to look at this problem in a moving reference frame. So rather than look at the because actually this is an unsteady state problem because at any instant of time you will have one particular portion occupied either by oil or by water okay. So just like yesterday we went to a moving reference frame I go to a moving reference frame and I say look the walls are moving backwards liquid is stationary and what this means is you have these internal circulations. Now what we want to do is we want to understand these internal circulations because that is going to help in mass transfer and heat transfer and things like that. So when you are trying to do some kind of a reaction and let us say there is some species here which has to be transported from the aqueous phase to the organic phase or vice versa. This flow is going to actually help in moving the species okay. So what one wants to do is one wants to understand how these vortices are actually going to be developing and whether we can get some idea about the magnitude of the velocity. Of course one approaches do CFD okay and the other approaches see if we can get some insight without doing CFD. And like I told you at the beginning what you can do is you can get these analytical solutions get some idea and if you are really interested you can do a CFD and get a more rigorous solution and in some limit the CFD can be validated by this analytical solution because at the end of the day CFD is going to always give you some nice pictures nice graphs and results. So the numerical accuracy of these results can be verified only by verifying this and some limit for example that gives you some confidence in your CFD results okay. So the idea is removing reference frame the wall moves back okay and in each slug we have internal circulations okay, internal circulations and this is important to understand mass transfer for example in reactions. So typically what will happen is there will be some species here and another species in this phase both have to come together to one phase for the reaction to occur okay and this convection is going to be deciding the whole thing. So how do you go about analyzing this? So the point I am trying to make here is this problem is very similar to that problem okay. You have a rectangular wall and the only difference is the boundary condition here. Here I have a solid wall but here I have a liquid-liquid interface but if you neglect the fire that is going to get deflected that means again perpendicular component of velocity will be 0 but you will have tangential component of velocity for example okay. So how do we go about, so this is just a motivation for doing this kind of a shallow cavity problem okay and typically in micro channels the slug length can be 5 to 10 times that of the diameter. So maybe we can push our luck and try and get some understanding of the flow field here using the shallow cavity limit. So what we will do is look at the flow in the original problem that we had in the shallow cavity and this is the problem DL maybe I will do what has been done in Gary Lille U0. In Gary Lille he has this business I think this is the x direction and that is the z direction. The lower plate is the one which is moving in the U0 with the velocity U0 in the positive x direction okay. Clearly what is going to happen is liquid is going to get dragged and going to form some kind of a vortex okay. This whole problem can be analyzed by dividing this entire domain into 2 parts okay. The central portion here which is the core region and the portions on the other 2 sides which is the near wall region okay. So I am dividing the entire domain into 2 portions. The central portion which is core and here where the fluid is actually going to be bending backwards. So there is a difference in the physics in both these regions. For example if you focus somewhere in the central portion of the core region you do not have the effect of these walls okay. For all practical purposes you can view the flow as being almost parallel only thing is the flow is the positive x direction in the lower portion and in the negative x direction in the upper portion okay whereas here and therefore for all practical purposes you can imagine that the vertical component of velocity is 0 I mean in some limit of course there is small vertical component of velocity but that is going to be negligible whereas here the vertical component of velocity is going to be comparable to the horizontal component of velocity okay. So in the core region the u and w sorry w is much smaller than u whereas near the wall the w is comparable to u. We are also going to look at macro fluidic applications and very small channels and the flow through the small channels the characteristic Reynolds number is going to be very low okay. So we are talking about very very slow flows. So what we will do is we will try and analyze this situation using the low Reynolds number limit. So rather than write everything and then put Reynolds number equal to 0 I am just going to at the beginning itself put the inertial term is equal to 0 write my equation of continuity and equation of momentum okay. So let us do that. So we focus on lower Reynolds number flows which means we drop the inertial terms on the left hand side of the Navier-Stokes equations okay. And what am I left with the equation of continuity which is du by dx plus dw by dz equal to 0 and then 0 equals minus dp by dx plus mu d square u by dx square plus d square u by dz square okay and 0 equals minus dp by dz plus mu. So what I have done and gravity I am not worried about just imagine the gravity is actually absorbed into one of these pressure terms okay as a gradient. So this is your modified pressure. So that is my equation of continuity the y direction is outside the plane of the board I am neglecting. So this is the regular thing that we have. So what we want to do is we want to simplify this make it dimensionless okay and then exploit the fact that d by l is very much lower than 1 and see what kind of simplification we are going to get. So see this business of the length scale in one direction being much smaller than the other is something which is you have seen in boundary layer flows for example okay. The thickness of the boundary layer is very very small. So what is the argument you make over there? You say that look in order for the equation of continuity to be satisfied for both the velocity component both these terms actually contribute okay. The characteristic scales which are written down there that w is much smaller than u we need to have an estimate clearly what is the characteristic scale in the of the velocity in the x direction it is u0 because that is the lower plate velocity. What about the characteristic velocity in the w direction that is going to be decided by the problem here in the sense that both these terms have to contribute okay and I am going to scale the length in the x direction with l and the length in the y the z direction with d because those are the characteristics scales in the respective directions okay. So u characteristic in the x direction is u0 x characteristic is l and y characteristic is sorry z characteristic is d okay and we need to know what is w characteristic okay.  So the idea is that these two terms have to balance each other and they can balance each other only if this is of the order of magnitude 1 and so this implies that w characteristic is d by l times u0 or epsilon u0. So it is epsilon times the u characteristic okay and so what I am going to do now is I am going to use this in my momentum equations make them dimensionless okay and get an idea about what is happening. What I want you to understand is the regular flows when you have a pipe flow the pressure drop is something which you impose experimentally okay whereas in this particular problem there is going to be a pressure gradient which is going to be decided by the flow okay. So dp by dx and dp by dz is something which I do not know something which I have to find out earlier the second point is a flow you said because that is a pressure driven flow that is controlled by you experimentally. So you impose dp by dx and then you find out what the velocity field is you get a parabolic profile okay. Here remember the flow is going to be driven by the wall and so dp by dx and dp by dz is something which I need to find out okay. So let us do this I also do not know what is p characteristic because the characteristic pressure is going to be something which is decided by the flow and the fluid properties clearly things like viscosity okay and the dimensions of the channel. So p characteristic is also an unknown.  I like to get d by l out so I am going to take out d square and the z direction I have d that comes out. So I have d square by l square here okay. Remember this is made dimensionless with l that is coming here this is made dimensionless with respect to d so that comes here I am taking out a d so that d comes there. So clearly this d square by l square is epsilon square. So if I have chosen my characteristic scales properly what this tells me is that the second derivative in the x direction is much smaller than the second derivative in the z direction. See the z direction my distance is very small so that the variations are much sharper. So when I have to compare these 2 I can actually neglect this in comparison to this okay. So basically this is an order of 2 orders of magnitude lower than this depending upon epsilon. This is an epsilon square term but what I need to do is I need to choose my p characteristic so that this pressure gradient in the x direction is going to balance the term in the z direction the second derivative of the z direction okay. So then only this will balance that. So I am saying I am going to neglect this compared to this okay. So this is epsilon square that is epsilon square and I have 0 equals minus dp by dx times p characteristic by l plus mu u0 by d square times d square d z star square. Now p characteristic is chosen as mu u0 times l divided by d square or mu u0 by l times 1 by epsilon square okay. So basically the characteristic pressure which is actually developed inside the gravity is given by this okay. So if you choose this then this becomes equal to that and your simplified equation of momentum in x direction is minus dp star by dx star plus d square mu star by d z square that is your dimensionless equation of momentum okay. So this pressure force basically the 2 important forces are the pressure force and the viscous force okay. Gravity anywhere you are neglecting inertia is gone so that is and there is something very similar to what you have seen in your second partial flow you have pressure and you know your viscous force. Only thing is I need to account for this guy bending back and all that and dp by dx is not known to me okay. So now let us do the other direction 0 that is the z momentum equation okay. That is what we have to do and what I will do is go to the other side of the board. I am going to start with this by d z star. This is p characteristic which I know and this is which I found from that and this is going to be given by d plus mu times w characteristic is u0 times epsilon okay that comes out and I do my usual stuff which is bring a d square outside here right and I am left with so I have the same stuff l coming as the characteristic so that l comes there this gives me d, d comes out, d comes out that d goes there okay. So now remember what is p characteristic?   So in the limit of epsilon tending to 0 or if you actually did a perturbation series solution and if you found out the solution in terms of a power series okay. So what you would get is in the limit of epsilon going to 0 this term is going to be negligibly small compared to this okay. So if you look at the terms of order epsilon to the power 0 this is going to give me minus dp star by dz star equals 0. In other words the pressure variation in the z direction is not there clearly the region is so thin in the z direction for all practical purposes you can actually neglect the pressure gradient in the z direction whereas the pressure gradient in the x direction is given by this momentum equation which we wrote over there okay. So basically what we have done is we have used the fact that epsilon is very small and rather than do a very formal power series expansion what you should do is now you should seek p as p0 plus epsilon p1 w as w0 plus epsilon and then equate coefficients but those equations are independent of epsilon. The epsilon is occurring only here so I am just getting the zeroth order solution directly by putting epsilon equal to 0 okay. I mean your zeroth order solution or the base solution how do you find just put epsilon equal to 0 you get a base solution. So I am going to get the base solution just by putting epsilon equal to 0 okay. You can do a more formal thing like we did earlier and then look at the first term then you will get this because we need to solve and now I am going to drop all the stars okay 0 equals minus dp by dx 0 equals by dz these are the terms at epsilon to the power 0 these are the 3 equations which we have. So let us look at how we can proceed what does this imply dp by dz is 0 implies that the pressure is a function only of x okay is 2 thin in the other direction so neglect the variation that direction this implies pressure is a function of x okay. So if pressure is a function of x alone okay then I can integrate this d square u by dx squared dz squared equals dp by dx that is from this equation okay. For my equation of the momentum in the x direction d square u by dz squared is dp by dx this is a function of x I am going to integrate this twice but since this is a partial derivative in the z direction what I have is these constants we are going to come they can actually be functions of x okay. So integrate this once you get du by dz equals dp by dx dp by dx times z plus c1 of x okay integrate this one more time you get u equals dp by dx times z squared by 2 plus c2 of x these guys are functions of x because I have a partial derivative I have total derivative I have been constant okay. So remember u can be a function of x because the dp by dx can change with x that is what this means dp by dx remember the function b is a function of x so since pressure is a function of x I am allowing for the fight that u can change yeah yeah yeah z that is right. I thought I wrote z but I guess I did not okay. Now you have to put those boundary conditions what are the boundary conditions at z equal to 0 u is 1 because that is how I made a dimension list and that z equals 1 I have u is 0 because the upper wall is stationary right. So when I put z equal to 1 when I put z equal to 0 I have u equal to 1 okay that tells me c2 is equal to 1 c2 of x is 1 u of 0 equals 0 implies c2 of x equals 1 okay and at z equal to 1 u is 0 and 0 equals dp by dx times half plus c1 plus c2. So c2 is 1 and therefore c1 is okay that is c1 so now I actually have the expression for my velocity u is dp by dx times z squared by 2 plus c1 is c1 x is dp by dx times half minus 1 times z plus 1 okay. I am going to group my dp by dx terms together which one minus dp by dx yeah yeah okay thanks yeah as always you guys are right man and this is minus right so I need to put a minus here I think that is it. So that is your velocity field and it is something like it is a parabola of course and remember but have you solved the problem yeah we need to find w but we know u we know we do not know u because we do not know dp by dx dp by dx is something we said I need to find out what is dp by dx remember it is not that I am imposing a pressure gradient it is the wall which is moving. So how do I find out dp by dx I need to use some condition about the flow. So let us look at to give an idea and to prompt you yeah yeah so I am looking at the core region right and the core region how is the flow somewhere on the top is going from the bottom is going from left to right and for all practical purposes you have this kind of a flow. Now what do we expect is there a net flow across this line you have a confined liquid liquid is confined whatever liquid is going to go from left to right we have a steady state situation okay whatever liquid is going from left to right must be the same as the liquid is coming from right to left okay. So what that means is the volumetric flow from left to right must be balanced by because there is nothing the liquid is not leaving your 2 walls you have 2 rigid walls the liquid cannot go out. So whatever liquid is coming from left to right must actually come back from right to left. So the total volumetric flow rate across this line must be 0 okay and that means the fluid going from left to right across in the fluid the flow rate equals the flow rate from right to left okay which means the net flow rate must be 0 or integral u dz from 0 to 1 must be 0 okay because I have confined liquid and then I am just moving this fellow so I am going to use that condition and of course I know u I am going to use that and find out dp by dx. So put this here and if you do the algebra you will get this is used to find dp by dx equals 6 okay. I mean you can just do this integration and you can find out that dp by dx is 6. So what that means is dp by dx is indeed a constant okay and something similar to what you had for your Heggen-Boysel flow when you say that the pressure gradient is a constant. So if dp by dx is 6 now you go back to that equation earlier we said p was a function of x but I know it is linearly varying. So dp by dx is constant which means that u is not a function of x, u is a function only of z okay. This implies u is a function of z alone it is independent of x okay. So u is independent of x therefore what this means is you have something like a fully developed flow situation d u by dx is 0 okay. That means d u by dx is 0 I will just say it is analogous to fully developed flow and from the equation of continuity dw by dz equals 0 from equation of continuity and since you have 2 solid walls w is 0 at the walls therefore w is 0 everywhere implies w equals 0 everywhere. So what we have done so what have I done we basically got an idea about what the flow field is at the 0th order when epsilon is very very small when epsilon is 0 okay. So the 0th order solution tells you that there is no vertical component of velocity in this core region what I am focusing okay. The velocity is almost fully developed so there is no change in the x direction and the exact dependency on z is given by that just put dp by dx equal to 6 you will get that. So you will get something like I mean if you really did the and plot it or something we put z equal to 1 that has to be 0 which is I put z equal to 0 you get some 1 or something okay yeah dp by dx is 6 3 this is z is it yeah thank you yeah this is z okay yeah yeah then I am okay because z equal to 0 should be 1 I was wondering it is not satisfying the boundary condition out of all of this. So yeah now z equal to 0 to 0 and z equal to 1 that is happening that is good if that is happening then everything is fine yeah z square minus z plus 1 minus z yeah. So 0th order solution is like this okay and this is 1 actually bottom the profile you get something like a parabola which is bending back like normally you have a parabola which is 0 and the 2 walls but here you have a parabola which is 1 here drags and then actually goes back to 0 okay. So let me see if I can draw this properly if I draw this properly it is 0 here then it is something like plus 1 is it yeah something like this this is 0 and this is plus 1 of course this is plus 1 that is the value of the velocity okay. So varying from plus 1 to 0 moves to the right and then bends back this is also not right this is also not right I really need to plot this function this is not right why is it not right yeah that is right this is not correct this is not correct. So what is the right thing clearly this is wrong nothing goes beyond 1 that is one reason and the velocity has to be negative and the way I have drawn it everywhere it is positive okay. So you need to draw it right and let us draw it right for a change which is going to be like this 0 and this is plus 1. So that is basically one application for shallow cavity flows and then you can do this also for the near wall region and then you can do it for different boundary conditions and stuff like that that is I think with that will stop.


Hi, I'm Marco Varone and I'm a PhD student in the lab of Professor Giovanni Ciriello at the University of Lausanne. Today, I'm happy to introduce you to Cell Charter, a framework to study the special organization of tissues from special omics data. So I will show you how it works, how it was the base for an interesting discovery in the study of lung cancer, and something that I'm showing for the first time, which is, let's say, unconventional use of Cell Charter to detect artifacts from immunofluorescence data. So tissue architecture is being intensely studied using techniques like single cell technology where every individual cell in a sample is separated and then sequenced. However, this process makes us lose the information about the original location of the cells in the tissue. But in the last years, special omics techniques have emerged as a new tool to study tissue architecture because they allow to capture the molecular information RNA for special transcriptomics and proteins for special proteomics, while maintaining knowledge on how the cells were arranged specially in the tissue. And so in addition to the usual cell by gene matrix, we also have the coordinates of every cell in the data set. And so these data are having a huge success in many fields of biology, such as developmental biology, neuroscience, and the study of diseases like cancer. And so this special information allows to complement cell clustering in identifying cell types and states with special clustering, which means clustering cells based on the composition of cell types and states around in the neighborhood. So special domains represent cellular niches where specific cell types tend to co-localize. This pushed us to develop Cell Charter, a framework to identify, characterize, and compare special domains. The workflow of our special clustering method is the following. We start from multiple slides of special omics data, where every point here is a cell or a spot containing multiple cells. And for every cell or spot, we have molecular information, such as RNA, protein, or even multi-omics data.  And then we use the special information to perform what we call neighborhood aggregation step. And this is the part in which we incorporate the molecular information of the neighbors into the cell data. And this neighborhood aggregation is fairly simple, but that's what makes it extremely scalable. And to do that, we encode cells in the special omics experiment as a network, with cells connected if they are in special proximity. And here we use the term cell, but of course this study also offers spots in case of technologies that don't have single-cell resolution. And so then for every cell, we do the following. We take the feature vector of the cell, and then we move to the first hope neighbors. So the neighbors are distance one, and we take the features. We aggregate it in some way, and for example, taking the mean, and then concatenate with the results of the previous vector. Then we move to the two hope neighbors to take the mean of their features and concatenate it again. And we repeat this until we reach a certain distance L, which is usually not big, around three or four hopes. And the final features of the cell are the concatenation of these vectors. And so we repeat this for every cell in the dataset and obtain a matrix of cell by this new set of features that include also information on the neighbors of every cell. And then we can use standard clustering on this matrix using a Gaussian mixture model to obtain our special domains. But in my PhD, we're interested in studying intratumor heterogeneity. So can we use cell charter to characterize it? Intratumor heterogeneity can manifest itself in two ways. A heterogeneity of the tumor cells mean that subpopulations can form from selected mutations or by adapting to different environments and tumor microenvironment heterogeneity. Meaning that within the same tumor, cancer cells can be surrounded by different cellular niches, and this may influence how they evolve. And it's important to note that these two types of heterogeneity are not independent, because different phenotypes of tumor cells can induce changes in the microenvironment and vice versa. And so we analyzed a special transcriptomics dataset of lung cancer patients from the nanostring cosmic technology, and among all domains identified by cell charter, some of them really picked our interest. Two domains were almost exclusively composed of tumor cells, which are the cluster 0 in pink and the cluster 12 in brown. And we can see this through the cell type enrichment plot in the top right. Here the size of a dot is proportional to the enrichment of a certain cell type in a certain domain. And these two tumor subpopulations are molecularly different. The pink domain is undergoing response to hypoxia, which is the lack of oxygen, while the brown one is more proliferative. But what is interesting is that the two domains are in contact with distinct special domains. In particular, the pink domain is in contact with the one in green, enriched in neutrophils and NK cells, and the brown one is in contact with the light blue domain, enriched in CD4 memory T cells and other tumor cells. And this wasn't the only patient in which we saw the first association between hypoxic tumor and hypoxic tumor niche and the neutrophil niche. So we saw it in also other two large-scale special transcriptomics and proteomics data sets of lung cancer. And so this analysis showed that through cell charter, we were able to characterize the two types of intratumorogenicity that I described before. We saw two subpopulations of tumor cells with different transcriptional states, but also surrounded by different microenvironments. And we showed all these results in a publication that came out in last December. But for the purpose of this video, I also wanted to show a sample that we did early on during the project, but it didn't end up in the publication, which is how we used cell charter in a slightly different way from what we designed it for in the first place. So I was analyzing some immunofluorescence data. This is, for example, a spleen where almost all cells are positive for the marker CD45. And sometimes the immunofluorescence experiment can give some artifacts where the antibody is not washed away properly. And this leads to some false positive signal that sometimes cell segmentation algorithm can mistake for real cells. A possible solution would be to find a better segmentation algorithm, but an alternative would try to find a way to identify and filter out these false positive cells. And if you look at the image closely, you can see that the areas of true tissue show quite some variability and heterogeneity in the expression of the CD45 marker, while in the artifact area, the signal is very smooth and constant. This means that when we construct the special features of a cell in the true tissue area, the neighbors are going to have heterogeneous value for that marker, while for a cell in an artifact, all these neighbors have very similar values. And as I mentioned before, one is not limited to use the mean to aggregate the neighbors values. For example, we can use the variance. The aggregation of the neighbors in the true tissue will have a moderate variance of their values, while the variance for neighbors of the artifact cell will be near zero because they have very similar values. And to show this on our sample, we can plot the mean neighbor variance for each cell, and we can clearly see which cells are an artifact because they're darker in lower variance. And on the right side, we see the distribution of these variances with a sort of bimodal distribution. We can easily set a threshold to separate the two modes, and we can see that it perfectly identifies the artifact that we can then filter out. This is something that we didn't show in the paper, but shows the flexibility of choosing the aggregation function that better suits the type of signal that you want to capture. To conclude, I give you a brief sneak peek into cell charter, which is a framework that we developed to study cellular niches from specialomics data. And I show that in the context of lung cancer, tumors undergoing response to hypoxia seems to be associated with the presence of neutrophils. However, we still don't know which causes which, and it's something that we would like to explore in the future. We'll learn more on the computational and biological side in the paper, so if you're interested, please give it a look and let me know what you think. And finally, I showed a use case demonstrating that the simplicity and flexibility of cell charter allows to use it for purposes different from the original one. So if you want to know more, check out the paper and the repository, and of course if you have any questions feel free to contact me and I will be happy to hear from you.