I think a few might be on your screen.  It's on the other side of the windshield. Hanging from the poles. Oh, I gave too much of a hint. That was too much. An empty step deck behind me right now. And we've crossed into Minnesota, USA. I gotta go down here and pick up a preloaded trailer. It feels good to be back down here again.  So we're on the way down to Thief River Falls, Minnesota. It's a couple hours south from our home base in Manitoba. Tolstoy, Manitoba into Lancaster, Minnesota. We're going down highway, what is this, 59? This is highway 75. I think it's 59 until we get to the US border then it turns to 70. I don't know. We're on the eastern edge of Minnesota here. Pardon me, the western edge of Minnesota. It's good to be back with our American friends. They've welcomed me back again. Across the road at Pembina, North Dakota into Emerson, Manitoba, because we'll be loaded then. Oh, and here's border patrol. Wait, maybe not. No, never mind, I just thought of border patrol. Go and check out what's the sugar gosh doing down here. But if you pull them over, you gotta check them out. That's you doing it. So we're here and everything has been changed around since I was here last. I haven't been here in a couple of years, but this used to all be wide open and all the flatbed trailers would be loaded over there and here. Now I see all the empty ones are here. Another one over there, I'm gonna put mine over here. And I see our loaded ones are over there. I'm guessing I'm taking one of those. I'm not too sure, but we're back in America. Everything is so much nicer.  But the budget down here to build infrastructure, this has had a bit higher than our budget in Manitoba. All right, we got a big province, not so many people. We kind of like it that way. We like being secluded, it's quiet. Not a lot of people around is too cold. Most people don't want to come to Manitoba. I don't blame them. And we like it the way it is now. However, with few people on a big land mass and all this empty land, we do have a lot of territory to maintain. And a lot of our taxes go into our healthcare system, which as a Canadian, I'm completely fine with. I know that it gets abused, but especially going through everything we're going through right now in the world, it's nice to know that if you need a doctor, that you can go see a doctor and you don't owe the doctor anything when you leave. All right, it's all sort of collected from us all as we live our lives. And then as you get older, it's there. But I don't want to turn this into a healthcare topic. Keyboards are firing up already. I can hear it over there, okay? Let's talk about infrastructure and roads. And the US down here spends a lot more money maintaining their roads and stuff. And it's just better built, to be honest with you. Doesn't mean that I don't like my country any less, I really do like living up there. And I don't mind the roads the way they are. You know, it could be worse, they could all be gravel. Well, then again, most of them are gravel. But all of them, even the main ones could be gravel though, it would be bad. So at least we got paved roads. This, maybe it's just cause it's a little different. I, maybe it's just all in my head, but it is nice to be down here again. I always love coming to visit the US. And I'm only allowed to visit now for work purposes and essential purposes. And I can't wait for them to open the borders up again for recreation purposes or pleasure purposes, whatever you want. I can't wait for them to open the borders again and let us just come down for a visit. For no reason at all other than to enjoy the beautiful country. I feel like we might be coming close to that, but I could be wrong, I don't know. I hope so, cause I'd love to come down here. I'd like to go down to Sturgis for bike week. That's what I'd like to do, but I don't think it's going to be open by then. That's next month already. Who knows, maybe. Look at that American air. That American asphalt. In a Canadian truck, eh? Just down here for a visit, eh? Don't mind me, I'm just picking up some snowmobiles, eh? Getting ready for the winter there. Picking these up, bringing them back. Took a little while for them to figure out which trailer for me to take. This one was most pressing for the 108 DB. So let's tire down, go get our paperwork, and make our way back to Canada. You guys down here in America have a very hot sun. You gotta do something about that. It's a problem. Got everything tied down here. Didn't have a ratchet that would meet the right spot at the back here, so I had to use a manual forewrench ratchet, or a portable, sorry, manual. I've just gotta wrap this around here. It's such a way that this extra, like this, like that, it's not gonna fly away on me. Where can I put this? I can always put it back there again. I like to have it nice and neat tucked up in here. Ah, I know. I'll go around it like this. I'll sort of pin it to this. So, no, no, no, we want it to pull it shut, not pull it open. On this side, okay, there we go. Around, oh, thanks, though. Now it's so pretty loose. Ah! Sometimes you just gotta get a little creative. That should work. Keep my eye on it. Time to go home. Time to bring these big old American machines up to Canada where they can be enjoyed. I think these are snowmobiles. Hello? Oh, no, quads. That would make a lot more sense with that ball of fire so hot in the sky right now. I was wondering, why are we bringing snowmobiles back home? No, no, no, these are summer toys. Summer toys, okay. Cool. I guess I should roll these up first.  That's a little one, but it's awesome. I like it. So I got my load of main machines. Open my, I just checked my straps to make sure that they were tight. I still kind of see them flappin' around a little bit by there. See, you can't crank the straps down completely like really hard on these crates because you'll break the crates. You want to strap them down tight, not too tight but not too loose. Find the sweet spot. So yes, we are headed back up to Canadian. Just a short visit. I know I'm sorry to disappoint you. You know, maybe one day we'll go on a road trip and our personal vehicles for holidays down in the US. We got friends we want to visit and, you know, we're big kids. I want to go to Disney World. So we'll end up down there again but for now, this is where we're at. Beautiful country out here. This is the Manitoba sign. We're back in Canada. Nice little short trip into the US. It does feel different. You know, it looks exactly the same and the scale's open. That's not a very nice welcome. It does feel different, you know? Even though everybody looks and sounds exactly the same, maybe it's just in my head, you know? It feels different. This feels like home. That feels like vacation.  So enjoy that. You're welcome.  It's like, hey, welcome home.  I've said that before. So I'm very nice to ask how heavy people are. Weird way of getting in here. Well, look at this. They repaved everything. That's about time. I'll compliment them on that. You remember how bumpy it was going through here? All right, hopefully they let us through.  There's a, that's life right there. Sometimes you're the windshield, sometimes you're the bug. I think that's how the saying goes, right? I don't think I'm going fast enough for him to keep blinking the light. Sometimes you're the windshield, sometimes you're the bug. In this case, you guys were the windshield. Lucky you. And this date took way longer than I thought it would. And I haven't really been dragging my feet either. It's just, there's so many more steps when you cross the border. Gotta go here, gotta stop here, gotta check in here. Gotta make sure this paperwork is done over here and that paperwork over there. That guy's brave sleeping at the scale. I would never do that. Now is this a stop sign for me? Why is it way over there?  That's, as long as you're on their property, they can inspect you any time they want to. I'll say that they would, maybe they'd have some common decency and wouldn't. I wouldn't be able to pass them, you know, an overambitious officer. Maybe they're having a bad day, they wanna make your day bad too. There's a big parking lot there, we'll tell you. Welcome to Morris, home of the Manitoba Stampede. It's like the Calgary Stampede, except, itty bitty. It's actually pretty cool. I haven't been there, I've always wanted to go there. The last couple of years has been canceled, obviously, but it's actually pretty fun from what I've heard. I think that looked like my boss's car. I think that was him anyway, he waved. We're back to the Canada flags up on the light posts. What was I talking about? I got distracted by the boss man driving past in his fancy car. Ah yes, the Stampede, Morris Stampede. I've been meaning to go and experience it once. I guess we'll have to do that once everything opens up. Manitoba's been a little bit behind other provinces in Canada in lifting all mandates and stuff. I know we're on the path towards that right now, so things are looking up. Alberta is ahead of us, the Saskatchewan's ahead of us. Of course, everyone's ahead of us, I mean. We're Manitoba. Can't be the first at anything. Don't want to stand out, you know? The nail that sticks out gets hammered, so we just sort of, you know, say somewhere in the middle, somewhere in the middle. I think most of Canada forgets we exist most of the time. Like talk to your average Canadian, like not me. Talk to like, if you ever find a Canadian anywhere, ask them if they know anybody from Manitoba. I can pretty much tell you they're probably gonna say, Manitoba? Nope. That's one good thing about my videos, I'm putting this on the map. Just reminding everybody, hey, that's Manitoba's right here. We still exist. You always keep flying over us, and that's fine, you can keep doing that, but just remember, we're still here. Oh, you want to race, bud? You want to race? Let me show you the power of my Peter. Show me some more power in that, bud, if you want to get past me. Come on, I'll show you what you got. I figured, yeah, he's got no governor. That's not fair. Here can go faster than my Peter. It's not my choice. It's been really nice sort of hitting the highway today, going down to Thief River and back. It's almost makes me miss the highway, the long trips, you know? Of course I missed them. I love the highway, I loved that job. I love being over the road. But, you know, I love my family more. And right now, right now I just need to be at home. No more trailer behind us. Dropped it off in the yard there where they can either get it ready for the highway driver or they might need to unload it. Park the truck. Tuck it away in my little corner back here. This is my space back here. You'll leave it alone. Peter that I'm hearing that I'm done. And we'll go home and enjoy the weekend. Got all my stuff. Until we meet again, girl. Have a good weekend.  I'm inviting boys over, okay? Be good. Crazy kids. Oh, got that AC pumping. Man, you know, when you think of Canada, you probably don't think of this heat, but whoa! It's hot! I got in the last one in today. Look at that. Oh, watch out, look at that. Which reminds me, I left my time sheet in the truck and I need to mark down the time I'm leaving before I forget. Silly me, because if I don't do that, I'm going to forget. I know me. I know me well. Some might say I know me best. Some might disagree. I don't know. I leave it in my orange folder. There you are. I forget to every single day. Lookie-doke, lookie-dokey. Okay, doke. Now we can leave. And then our paperwork and everything. So a couple more things to do before we go, but we should be out of here in about 10 minutes. Well, I left my trailer here to be unloaded, but it kind of defeats the purpose when the next driver comes in and parks right beside my trailer. They have a shunt truck. They'll move it if they need to move it. Or, hey, it's not gonna get touched on Monday, probably, so. They can move it on Monday or I can move it on Monday. They'll figure it out. And look at this guy. There's a dump truck here. I thought I heard rumors that we bought a dump truck, but I don't know if this is ours or not. Look at this thing, shiny. I hope I get a drive that. Look how shiny that is. I wish my truck was that shiny. I've put in a request, but not for this one. I just put in a request for a shiny truck, but look at that. That looks fun. Are we getting into the dump truck business now? We got our fingers in every pie. We do everything. Everything. You need something hauled. We're the guys to call. We'll haul it. Okay, I'm pushing my button here. Excuse me. Excuse me, you're supposed to be open by the time I get here. Do you know who I am? Excuse me. The slowest gate ever. I need some Jeopardy music. Okay, there we go. Look at this. I'm like the last one here. There's nobody here. Even the shop's gone, gone home. Everybody's gone home. Who's Sugar Josh? Last guy here. Long day. But it was fun to go visit America again. Everything is still just as I left it, for the most part. For the most part. I miss going down there regularly. We have really nice neighbors next door. It's nice living next to them. And it's nice to go see them. But we're back up here in our home, Manitoba. And it also feels good to be home. I like it here too. We have a good region. Really good region. Anyways, I'm pretty tired. I'm gonna call it a day here. Thanks for hanging out with me today and coming all the way down to Minnesota with me. Hope you have a great weekend and I'll see you tomorrow.


Okay, there seem to be some streaming problem. I hope everyone can hear me and see me Let me know in the comments right now. Just so I know We had some technical problems Okay, let's see who's here checking the chat Well, if it's your first time my name is Robin Shaw and I am a youtuber and I live here in South Korea And we see Kavinu is here sleepwalker Leila Michelle hello Okay, all the regulars all the important people are here and the less important people will come late So hello everyone. Let's get started. If you have any questions, let me know and I'll do my best to teach you No tea today All right, let's see who's who else was here and and Shad CK Mike Schmidt MD Mubasher Okay, thank you, Michelle and sleepwalker. You can all see me. There was a little bit of a technical difficulty The live wasn't starting usually when I hit Start live It starts within about 10 seconds today. It wasn't starting. So I had to restart and I was worried I was worried something bad would happen, but nothing happened. We're all here. Let's get started How was your week and Leila's coming in with the Questions right away Did you get up to anything? Okay, that's an interesting question. Let's go to the board for this one I think I'm gonna make my Image a little smaller Did you get up to anything this weekend and did I use it in the proper way in the right place? Well, I Don't usually use this expression. So I'm gonna check it I'm not saying it's wrong. It sounds right. It sounds like something I'll put an alternative so it is possible to say this it's not wrong Native I'm sure native speakers say this. I don't did you get up to anything this weekend? This get up to anything would be the same exactly the same as did you Do Here we'll keep now. I can't match the color. I want to go back to the blue Get up to this would be the same as do Did you get up to? Did you do anything this weekend? So this get up to would have the same meaning as do And so did you do anything this weekend? Yes, I did. I went to the park So did you get up to anything this weekend? Yes, I did. I went to the park. It means the same thing and We can also say what did you get up to this weekend? And again the get up to Means do same thing So what did you do this weekend? What did you get up to this weekend? Yeah, they're both okay native speakers are gonna say that you could say get up to or just More commonly would just be did you do anything or what did you do this weekend? But that's okay. They let you used it correctly Our devices are not perfect sometimes unfortunately, well, I'm gonna blame YouTube for my errors today I'm not blaming myself. Sometimes it's human error, but today. I think it was a YouTube error Did you get up to this? Did you get up to anything this weekend? Similar question when someone says Did things work out that means is everything that means is is everything going well or not? Well, yeah, it's similar let's look at the the tense So the did is asking about the past tense So I'm gonna change you this Well here, let's change them both present tense first and All both past tense. Let's match the tense So if we're talking about now today, I'm gonna use our things Working out and Now is everything going well? So these are both present tense They both use the continuous form ing and yes, they mean the same thing Did things work out again? Let's change it to the past. Did everything Go well And yeah, that means the same thing. So both of these mean the same thing are things working out So is everything going well in your life? So You're going through life right now and I want to know If you're solving your problems and everything is okay. I could say are things working out Is everything going well and in the past Did things work out at work yesterday? Did everything go well at work yesterday? So they mean the same thing just match the tense Hello Frida Happy birthday MD Mubasher Ali Happy happy birthday to you And Kavinu hello, I'm doing well. I hope you're doing well too. Do you have any questions Kavinu? You've been studying English? Finny, hey Any other questions coming in? I had a Sundays are my busiest days because I'm filming new videos some Lot of new videos these days some are good some are not so good, but I'm trying to Film a lot. I filmed a lot of videos for my new Channel coming out soon about IELTS Yeah, I have to go to Seoul every Sunday. I just film videos on Sunday, so I film videos I go to Seoul about 8 a.m. And today I started Talking to teachers and things about 9 a.m. And I filmed until about 5 p.m. It's exhausting. I talked I met and talked to about 20 people today For the videos and it's hard work. It's very hard work Hello, Alyssa Fanny is asking does it work? I'm not sure what you're asking about does it work? How about does it work? What do you mean doesn't work? What does doesn't work mean? I'm not sure Fanny. Can you explain? I'm doing well for Eda Sleep Parker has a question. So let's take that to the board. Let's take that to the board Let's take a look what's going on Robin that's me Is it natural to say? He is liked by people. All right, let's break that up Is it natural to say? Let's put quotation marks. He is liked by people Or is it better to say? people Like him interesting question. Let's take a look I'm gonna get rid of this this these extra words And just focus on our two sentences He is liked by people People like him well sleepwalker you You perfectly identified the active and passive voice. So I'm gonna move people like him is the active voice and He is liked by people. It's the passive voice What's and let's change these colors active and passive So what's the difference between active and passive? Well, I'm not really gonna teach that but I'll briefly mention Subject verb object this is Subject and we're directing our action towards something that is the active voice and he is liked by people The receiver this is the receiver of the action and the receiver of the action moves to the front the focus of a passive voice is The receiver of an action and your question. Is it natural to say which one is natural to say? Well, both of them are natural to say But as a rule we should try to always use the active voice It's always better to use the active voice so people like him You can use the passive voice. That's fine. That's fine. It's not wrong But as a rule in English Try to use the active voice try to use the active voice. So I'm gonna say if you want a Real answer People like him is better Anyone else have questions? Let me know Michelle. You got any questions Alyssa? Fanny Farida Basher Covino Alright Layla says I heard a native speaker use Fish out and I tried to make my own sentence. I try to fish. I try okay fish out This would be idiom. I tried. Let's put a past tense. I tried to fish out. I My wallet. Okay, so it's a phrasal verb. There you go phrasal verb idiom Idiomatic idiomatic phrasal verb. I'm just gonna put the grammar points down here fish out Let's put a color. I don't know that color and Let's try to get us in just to show how Layla spread up fishing out was broken up All right, I tried to fish my wallet out of the garbage can did I use fish out properly in the sentence? Yes, you did. I tried to fish my wallet out of the Garbage can and what is fish out being?  I'm explaining fishing to catch the fish So we also have this expression fish out, which means you kind of dive into something in this case the garbage You're going in and searching trying to find something And pull it out.   So I went digging in the garbage searching and I fished it out like a fish Used it properly Covino in this week. I have been studying and reading Some lessons related to English. Sure. All right. Good. Let's take a look at your sentence Covino And let's fix up in this week Let's just cut. We do usually don't say in this week. We can just say this week this week I have been studying and reading some lessons Related to English. Everything else is great. This is good. I have been good grammar studying and reading Some lessons related to English. Good to hear keep keep it keep it up So Fanny continued lay this question. Does it work is not related to Lay this question about Just because the word has work doesn't mean it's the same Workout and does it work? That's not the same. So does it work? Doesn't work in that sentence How can you tell someone you don't like their Style teaching you want to flip this teaching style For filming videos or you found them. They don't know how to teach Okay, how do you can you tell someone you don't like their teaching style? When maybe when filming videos when I'm filming videos or I'm not sure what you mean here. This is where it gets confusing You found them How can you tell someone you don't like their teaching style when filming videos or you found them? They don't know how to teach or you found out maybe you found out They don't know how to teach I'm not sure what I'm not sure what you're trying to ask Do I tell people I don't like their teaching style on new teachers? You're talking about my story or you're talking about another video. I'm not sure what you're trying to say Leila Try it again Vijay Saloni, let's take a look he fell through the window causing the glass to break Looks good or he fell through He fell through the window causing the glass to break or he fell through the window causing It's the same What do you mean? Vijay are you pulling a joke? This looks like the same sentence. He fell through the window. He fell through the window Causing the glass to break causing the glass. Oh to broke This is wrong. All right. I got it. I got it right here Causing the glass to break causing it If we're using causing Something we we don't want to use past tense. We just want to keep it the infinitive to break So this this one's correct. He fell through the window causing the glass to break Similar sentence, let's see if we can make our own sentence Is he she? She ate too much causing Button on her pants to pop So we don't want to use I didn't say popped past tense I just use pop the button pop popped off present tense So sleepwalker. Oh, so active voice is priority. Thank you. Yes Everyone you you know a lot of students are always asking me, how do I make the passive voice? Probably because teachers gave homework change the active to the passive voice and yes You should know how to change active to passive and sometimes we use the passive voice, of course But priority should should try to use active voice as much as you can Peter Dell. Hello Technical My picture is not moving Yeah, I see my picture is not moving and I'm not sure why Well, well the show must go on Pictures not moving. Let's see if we can See there's something wrong with YouTube Oops, that's not Can you can you see the whiteboard? So if you can see the whiteboard, I'll continue on Spelling of whiteboard Can you if you can see the whiteboard? Do you see words on the whiteboard? The whiteboard is working. All right. Thank you. So we'll just continue I don't know why my video is not moving, but I can still keep teaching with the whiteboard Yeah, my my video picture stopped and Alyssa doesn't care Ali wants me to do his homework Please use prep positions. I live. Oh, this is your homework. I'll do a few I live in Barrow Razoo rum pure Maybe in rang per In rang per First one is my village second one district and division. I think it's all in in in Okay, Farida What's the difference between contagious and infectious are they similar with slight difference differences Yeah contagious as far as I know, let me check is just more of the spread easy to spread These are actually dictionary words so Yeah contagious here Highlight on the green or not that color So contagious is diseased. It's easy to spread and Infection means something can be spread. So What's the difference? For the most part, it means the same thing from what I can tell there might be some little difference. I think contagious Here's one little difference. I think contagious is more used human to human and Infectious can be like animal to human We don't usually use animal to human as contagious. So human to human is more contagious The disease is easy to spread and maybe animal to animal or animal to insect or animal to human is more infectious All right, this is Alyssa's question. Does the word? pontificate have a negative connotation after his presentation has Pontificated about his success for an hour. Well, I've heard the word pontificate, but I do not use it And I'm gonna check it because That's a big word for me Pontificate so does it have a negative connotation? It has no connotation to me because I don't understand it As far as I understand you're expressing an opinion, but if someone used the word Pontificate I might have a negative opinion not because of the word, but because the person used that kind of It's a big word not so common So I might not like that person for using such a big word now Does is a pontificate a negative sentence? I don't think our negative word. I don't think so I don't think it has a negative connotation. I Don't use it enough Says express one's opinion in a way considered annoyingly pompous and dogmatic So it could have nature according to one definition. It does have a negative. I just don't use that word. It's kind of old Yeah, I would say From the dictionary Seems to have a negative connotation to the to the user who uses that word But I'm not recommending people go out and use that word. Don't use but pontificate Convenience, sir. By the way, you're busy within the week. I'm busy every day All right, ladies trying again her sentence of what I want to say nowadays. You hired someone some Teachers for filming videos. Yes, but at the beginning when you found out they don't know how to teach How do you tell them that you don't want to work with them? Well, I hire teachers and if they don't teach well, I don't hire them again. So Usually I choose good teachers before I work I Do my best to find good teachers Yeah, see I am still If the whiteboard is working we can still learn Could you let me know which word you often use while writing instead of but well you can use however I Use but I like I like ice cream however Cake is delicious, too So, however, it's not exactly as a but but and if we go to the but Synonym what else? Let's do a still he studies a lot Still He is stupid So this is not so common, but we could use sometimes still as a bot But the best thing to use for a bot is bot Take a look here. Is there any mistake in my in my following sentence? I'm getting I'm getting started taking the rest of drawing courses. No I'm getting started it seems you don't want to use a present continuous there. I'm I'm getting start or you want to reduce the verbs. I'm Starting getting and started is two verbs get and start. Let's reduce it to I'm start. Oh, you got a third one I'm getting started taking as three verbs there I'm gonna reduce two I'm starting The rest of my drawing courses. How about that? I'm starting the rest of my drawing courses You don't want to use so many verbs Convenience sir, can this word be pronounced please features features? This is a chur's chur's features What this is from MD Mubash Ali. What do you do in your daily life? I wake up I work I edit videos I Write scripts I teach that's my daily life as a teacher Why that froze today, you know, I've been doing live streams for Years and my image has never froze before Let's see if I can fix it. Oh, I think I fixed it Tell me if you see me moving around I didn't need Think I fixed it and MD Mubash Ali is asking How do you pronounce my name so I would say MD that's short for Mohammed, right? Mubasher Mubasher, I'm not sure how you pronounce it Ali MD Mubasher Ali, I hope that's correct not working now. Okay, we got it. We got the image back Let's get rid of red. Let's go back to blue All right, this is from Layla the spoon slid out of my hand the spoon slipped out of my hand I checked the meanings of slip and slid I Am I found there similar too much? So what is the nuance between there? Okay Yeah, okay. I'll let you have this one So she's focusing on slid and Sliped so I don't have a spoon right now, but I do have a pen and our video is working. So I'll put the Pen and you know if if I move my hand The pen Slid out of my hand now. I could also say the pen Slipped out of my hand. So the same thing. So what is the difference?  What's the difference? Well, I think slipped means more accidental So You know the pen slid out of my hand. I Wanted it. I want it to slide out of my hand, but slipped is a kind of a more accidental. Oh, it just slipped Oops kind of it slipped. Oops So they mean the same thing just slipped would be a little more accidental that that happened But basically they mean the same thing that nuance Sai blue tyong So he blew tyong sir. I have to ask my friend about the well-being of her family member as well Then how should I say how are you and your family doing? That's looks good Or how are you in your family? Okay? Let's take a look at these two sentences. How are you and your family doing? How are you and your family? Same thing same thing both are okay both are good to use How are you and your family? Or how are you and your family doing? Both are okay. The sound is very low. Jeez. I got more technical problems. How's the sound everyone is the sound low? Robin, when will we have another vocab lab? Maybe March? Because I'm too busy now and Michelle has a question. So let's get on Michelle's question. Please. What's the difference between grasp and grip interesting also very similar words today and To me they mean the same thing They mean the same thing to me Let's take a look what the internet says Internet doesn't say much Well Same so Michelle I cannot find a differ there might be a difference, but to me Grasp like here's my pen again, and I'm gonna grasp it and I'm gonna grip it Means the same thing to me there might be some Some small difference, but basically they mean mean the same thing and You had a second question tired and weary or wait I'll go back. There is a difference between grasp and grip. I'm gonna say grip is more common So that might be a difference Tired and weary. I'm gonna say tired is more common, but weary Weary is kind of I think more of a very tired Let's see weary weary. I don't use weary too much. Yeah, so tired and weary weary is more of a very tired So If something said I'm weary, I would understand though. They're very tired. Okay, so that one's easier There's a little bit difference weary is very tired Ferreta has some questions How long have you been living in South Korea about 22 years do you like the life in South Korea? Yeah, I like it here Korea is okay. I've been here a long time because it's a good life Laila as you know, it's not good to start a sentence with but so it's okay to start a sentence with but Not informal writing. So if I want to start a sentence with another word instead of but So I asked you which do you prefer? Again? I keep repeating Laila It is 100% okay to start a sentence with but when you're talking to people you can start a sentence with But when you're chatting with people you can start a sentence with but But when you're writing When you're making formal formal speech or formal writing Then you don't you shouldn't use but you shouldn't start with but So if you're if it's formal writing we use however Use however Please pronounce my nephew's name. These are this isn't This is Mubash for this last time we're gonna do pronouncing names because that's not related to learning English. You're just I feel like a monkey Poke poke do this poke poke do that Because this is not English, right? This is not an English name. So why am I pronouncing it? You should tell me how to pronounce it. So in English if I saw this I would say Jamir rule Islam Jamir al-Islam Sleepwalker I came across the word arcs. It's connected with characters in movies, but what exactly doesn't mean Okay, a story are a story arc Stroy no we want a story So yeah, if you're watching Movies or TV shows They're gonna have an arc let's see if there's a year I'm just gonna post the Definition so a story arc is an extended or continuing storyline. So If you're watching a drama And You got four main characters and we're following the lives of four main characters and this show This character meets a new girl So the second show might be about that new girl the third show might be about that girl So that's a story arc that kind of new storyline of the new girl So this TV show with four characters might have a main story like these four characters are growing up in their life and But they will each have probably their own story arc their own special story So then this guy meets a new girl So a few episodes follow his relationship With that girl and then maybe they break up and that story arc finishes So we call it a story arc So yeah, just a storyline as you know, not the main storyline but kind of a Secondary storyline is the arc I'm a bit confused about the two following sentences You don't know how doing it You don't know how to do it. Well, I don't know where you saw this because this sentence is not English This is wrong. This is not a sentence. So we can delete this doesn't exist in English and This is the only sentence You can say you don't know how to do it. Is that a question or a statement? You don't know how to do it. That's the only way what I'm not sure where you saw that other one, but it is wrong. I Suppose your voice is low. Yeah, I I don't speak very loud Because I have neighbors and right now it is 1115 p.m. So I don't want to talk too loud. I Might wake my neighbors He came by to see if she was lonely one thing led to another and he stayed the night One thing led to another Hmm one thing led to another. All right, so This person is telling a story this man came to see if a girl was lonely and Many things happened. Maybe they had dinner. Maybe they went for a walk. Maybe they watched Netflix many many things happened in this story But this person doesn't want to Talk about all those things So to quickly summarize many events They're using the expression one thing one action led to another action to another action Many things happened, but they don't want to say all that they just said one thing led to another and The result of the story he stayed the night so when I read this sentence it seems like This this couple had sex he came to see if this woman is lonely one thing led to another's We can imagine that they became close and he stayed the night So it's often used in in sexual stories. So I'll do it another story myself. I Met a girl on the train One thing led to another and now we are married All right, so this is not so sexual but So I met I met a girl on the train First meeting and now we are married. Okay, so you can imagine the meeting point and the marriage point There was a lot of action in the middle. A lot of things happened. Maybe years of actions But I summarize that one thing led to another you can imagine a normal story You know, I met a girl we fell in love blah blah blah blah. I don't want to tell you all that story I just summarize one thing led to another and now we're married Alyssa is snooping around the same as stalking. Ooh, I was snooping on my ex-husband's Facebook profile Well No, they're not the same Snoop snooping around. I'll just Get everyone else to understand. So snooping around means kind of looking Looking for information you shouldn't be looking for So, you know, I'm curious about my friend So I'm snooping around his room when he's not there So I'm looking around his room trying to get some information about my friend So snooping around is kind of a little bit negative, but it's not illegal Stalking is illegal that is when you are Following someone getting getting involved in their life This is illegal. So If you use the sentence I was snooping on my ex-husband's Facebook profile Yeah, that's not illegal That's not illegal. I Didn't know you had an ex-husband, but you know, we learn we learn something every live stream Yeah, it's not illegal to check out your Ex-husband's Facebook so snooping on we could also use the word spying But it's not stocking stocking is a illegal thing where you're threatening someone Following them scaring them if you're snooping on your ex-husband's Facebook profile, he probably doesn't know you're looking But if you're stalking him, he knows you're following him So Alyssa do not stalk your ex-husband That's what I'm trying to say So he blew Taeyang does the word ought mean the same as should well. No, we have to say ought to is the word That's called a semi modal Does it mean the same as should? Yes, it does So in a sentence you ought to there you go ought to make sure you have that to they go together ought to You ought to know everything about it You should be knowing known it's If it's the same sentence we just change ought to to should Yeah, they mean the same thing You ought to know everything about it. You should know everything about it should is a modal Octo is a semi modal Mean the same thing Mubasher has a lot of questions today. Please other ways to say my power went out Well, my power went out is the best way my power went out My electricity Switched off But still my power went out is best my electricity switched off another one my I Think those I can't think of another way to say that My electricity switched off my power went out. That's all I have and sleepwalker So the whole way of the character in a movie. Yeah in a movie it could be There it's I think character or the story arc works better in TV shows Yeah, it could be in the movie of a character Yeah, it's possible, but I think it's more appropriate to use care a story arc Character arc in TV shows, but they work in movies When an electronic gadget it's not working Then what should be the proper to a It's not working As you said, it's not working. So my phone is not working or I could say my phone is dead My phone Has no power Okay, those are probably the main one. So I'll just change that my phone is not working My phone is dead. That's that's very popular. My phone has no power or the battery is Dead on my phone the battery is dead Dead which often means no power. This is dead. No power Farida Who Farida you got a You got an interesting question Farida. I'm not sure if I can answer on YouTube.  You've been warned be careful. It's not clean Now everyone's leaving my live stream right now to go Google good dominatrix All right, Leila I didn't expect This meaning of one thing led to another. It's an interesting meaning to me. Okay. Good to hear Palavi hello Welcome back Alyssa. Hey, that was just an example. Yeah, Alyssa sure All right Leila says I heard the instructor of drawing say we as artists get to draw both Shadow and the light so get to has the same meaning of have to In this case, I'm confused Yeah We get to draw I think it's yeah, I think you're right in thinking it's more of a have to Just the way they expressed it, you know, not a net not every native speaker is perfect at English. So You're right in your thinking Okay, what's the difference between I would go I will go Modals so I would go I would go to this is a You know if we're gonna use the if statement here and conditional I would go to the beach If it was summer, I will go to the beach All right, let's start with the bottom one. I will go to the beach. So it's a future plan Future tense. I will go to the beach I would go is You know, we is a conditional sentence. We're using if here. Look at that if So it's a possibility It's not an exact plan. This is an exact plan. I will go to the beach next week I would go to the beach. So it's an imaginary situation It's possible. I would go to the beach if If It was summer now is not summer. So I'm not going to the beach. Okay You you can't have a sentence This is impossible. So a lot of people confuse. Okay, if if If I say I would go to the beach, I will go to the beach. What's the difference? No, you cannot just say I would go to the beach This is requires more information in this sentence Okay, I hope that helps Yeah, sleepwalker bdsm. Yeah, you sleepwalkers an expert on dominatrix. I can see Uh pilavi, could you please tell me what is f word? Well, I can't tell you so Uh, it could be the f word is a bad word. So in english There is a bad word that starts with f We can't say it because it's bad. So we say the f word Because I can't say it. It's youtube and this is a clean Live stream. I can't say that bad f word. So you have to imagine. What is the worst? Bad word in english that starts with f I can't say it, but I can say the f word and you should understand what it Understand what what it means Layla has I feel too hard to pronounce this word. Oh, it looks like a difficult word parallel parallel parallel parallel Alyssa Am I working overtime? What time is it? It's 11 30 and we're gonna finish up in a few minutes I'll finish up these questions Is this correct? We were on the edge of our seat Intrigued who will win the competition Low and behold, I think that's low and behold The power went out Yes, that's correct. I'm not going to teach all the points of this You got a lot of things you got a lot of idioms and expressions here edge of our seat intrigued low and behold We were on the edge of our seat intrigued and Google here is telling me after intrigued we should put about we We were on the edge of our seat intrigued about who Would win I'm making another adjustment. We're on the edge of our seat intrigued about who would win the competition You said who will it's okay Low and behold the power went out Okay, Layla has a conversation a I don't like to hear about that topic anymore. Please just drop it Okay, b. Okay. I'm sorry. Did I use just drop it properly? Above dialogue. Did he yep, just drop it Yep, you used it correctly. That means if you say just drop it, that means you don't want to talk about it anymore Please drop it or just drop it Don't talk about that topic anymore. So you used it correctly See the side phallic. Hello Layla Do native speakers use compound adjectives with hyphenated and commonly he's an open-minded person. Yes, we do Every day I use use those with hyphens appropriate preposition abide by please make a sentence with I can't understand it One of the most common please abide by the rules And abide by in this case will just be follow Just follow the rules abide by the abide by So abide by is more more of a formal follow of rules or the law So please abide by the rules very common sentence or please abide by the law Follow the rules follow the law Frida I unfortunately use the f word a lot, but I'm trying not to use it. Yes So instead of the f word you can you can say fudge Oh fudge Lots of important words today I heard a native speaker say What did you hear them say? I'm feeling way better. Does it mean I'm getting better? Yeah, I'm getting better. I feel way better ways used to emphasize It's a intensifier More better So let's Put in yesterday So if I said I'm feeling way better than yesterday now I can take out that way It's just an intensifier like very Or really So I'm feeling better than yesterday. That's all it means Today I'm feeling better than yesterday now. I put in the way I'm feeling way better than yesterday. So I'm feeling more really a lot more better than yesterday Kavinu your question is too big right now Could you confirm that there's a tense called conditional progressive tense or something in the language? What is your conditional progressive? Okay Or something in the language. How can I send this mean mean from that? I don't know the name of that tense Properly. Well, if you don't know the name I can only go conditional progressive Which the form here says would plus b Plus present Participal verb i and g an example sentence would be I would be traveling around the world Okay, I'm not going to go into detail because this this would take if Take more than a minute to explain uh, yeah, there is a there's a conditional progressive tense There are specific usages for it, but sorry. That's a little too much of a question to answer right at the end Kavinu Maybe next time and Mubasher says Please correct these sentences. Let's take a look how much charge you have on your phone. How much charge left? So this left means remaining on your phone I have 32 Two percent left would probably be how a native speaker says it. Okay, so in this case left Means remaining, you know the word re what did I write there remaining The word left has many meanings so, uh left like left right or Left I I went home. I left to home But in this case left would have re meaning of remaining. So how much charge do you have left? How much charge Here I'm going to move that left. Do you have left? On your phone and I'm going to change charge to power Or or how much battery? Do you have left on your phone or how much battery power? Do you have left on your phone? I have 32 left this This is more what a native speaker would say. How much battery power do you have left on your phone? How much battery power do you have remaining on your phone? I have 32 remaining. I have 32 left Uh, you helped me out last night. Thanks to you Sure thing. Do native speakers use sure thing instead of you're welcome. Yeah sure thing You're welcome. Sure thing is a way to say you're welcome. Sure thing. No problem And we'll bash her again. I'm going to end up I'm going to end this live stream in a minute or two Get in any last questions or comments. I'm going to finish up soon I'm going to the bathroom to take a shower. Is it a correct sentence? Yeah, that looks fine I'm going to the bathroom to take a shower. Yep Okay I'll have a get your vaccine. I couldn't call you because okay, let's take a look Jamiro is M. There you are I couldn't call you because my phone is dead. That is correct That's correct And Layla Did you start eating your new videos? You still film with the teachers? I think you mean editing You yeah, I slowly editing, you know, it takes me a long time to edit. We might see the The new video in March Maybe All right, thank you for watching everyone. I'm going to end the live stream now We had a few technical difficulties difficulties We had a good a lot of good questions Um I'm just seeing the final comments come in. Thank you for watching and uh I hope to be back next week with more energy. We'll see how we'll see what happens So good night, everyone. Take care and be sure to study English Um continue to study English. I know it's a struggle, but Keep don't give up. Keep doing it. So take care everyone


So, hello, everyone. End of the day, everyone is tired. I will try to be a little bit entertaining. So I am from Aberdeen. And actually this talk came after a good number of very interesting talks with rise a little bit of discussion. Particularly Andrea Stork the Overday, Andrea Karaniya Stork izgleda nekaj izgledajših reakcija. To je nekaj, da se počutite, z vsej hrabrištih fizicistov. Všeč nekaj izgledajši, nekaj izgledajši nekaj izgledajši biologij. Vse sem fizicist, tako da, da. Zelo je vse. V kandu, kaj imam počutiti, je tudi tudi, nekaj izgledajši, ki so evoči počke. Sveč, je nisem prijevno v svojo izgledanje več da je vse več, in je odpovojova na svojo vse vzostavljenje vsojoj, čudovite vsoje, in nekaj nekaj, nekaj nekaj, nekaj nekaj, nekaj nekaj, nekaj nekaj, nekaj, nekaj nekaj, In jaz je vsi obstahen odčivati, that this is in a very similar situation of what you encounter when you try to describe via the dynamic of fluids in more traditional physical set ups. Čest jah je, ki je to pričočen, tako je to svote, kdjeli zelo bilo nepoten, ki počtučijo tkaj semetri in počtuče okončne vršenje naši tem, ker je objevično objevaj nožnjih zeltikov. Evnoj bolje nedev ojunju. Neljere s vršenjem koncertem Piranic, ešte legcrivi so nisak všim počku, pričo to prične silni stren si.  To je ongojnja vrkla, tako je nekaj vrkla. Sreč smo nekaj izgledaj. Na različne, zelo, da se poživajte. V ideju je poživajte močnje. Sreč smo poživali o poživajte močnje. Jeste svoje dve izgledaj. Staljnje vrkla, šepe, vrkla in embryogenes in zebrafiskih embryo. In vse čo je zelo v abadju zelo, in nekaj občan, nekaj razladu vsak des travail, vse četko otvorega, Pravno je, da zelo, da ini nekaj interaktiv, vse del nekaj, analizovana in interasja in v tom, da je ono tako spokojovo in nešto evojenju aj in neč vzreti na vse. Tudi sarr, na povrstvenjem, ki da bi izgledali skoljiom nespečenje z vrvič plenty, če prvna su povrstvenje in ki se se pravati do trupov, Do they know where we have to go back? And how can you understand if they know where is their nest? But it could also be a problem that when you study the migration of large animal groups, are they going by a precise direction in mind, which can be dictated by a lot of different factors some individuals knowing where to go, magnetic field for migrating birds, configuration of the terrain, and so on and so forth, Or, they are just picking a direction, somehow a random, they find in internal consensus, there is nothing outside their group telling where to go, and then they go for a stroll, like they won't have some leisure. Like it's probably the case of the births of Irene and Andrea and many other people. Another example where this kind of question is very relevant, I've been discussing with Kizhejer and his collaborators in Dundee. They study cellular migration embryogenesis and the primitive straight formation in many embryo, in particular they study the cheek embryo, involves large scale highly coordinated flows, which involves 10 to the 5 of more cells. They believe, and there are some indication that this is driven by some kind of external field, chemotactic field, mechanotactic effects, so on and so forth. But the question, this is an example, let's see if it goes. This is some imaging from a paper of Dundee group, and you can see large migration flow here, cells on the boundary of the embryo. And this flow basically creates the primitive streak, which basically underlie the symmetry and the cordal spine of many, many, basically all vertebrates. So the question is, how can you tell in all of these cases if your collective motion is spontaneous or not, or there is something which is driving it? One, of course, can look at the time series of the orientation, so I can look where the group is going. And we know that if, I mean, this is basically what Offer was doing, that if you look at the direction where you're pointing, that the angle which defines the direction in which you are moving into dimension for simplicity, if you're not directed by any external field, it's going to perform a random walk, a persistent random walk with a certain length. And so one can think that in the other case, otherwise your animals, your particle know where they go, and so you expect them to fluctuate less. And indeed, here there are two cases, they are taken out of the simple Vyček model, we have seen it many times. So you can see immediately, these are time series of the angle, how the angle changes in time. So here I have checking the quantity for 100,000 time steps a lot. There are two different cases. I can tell you one came from a directed motion where there is an external direction, which came on top of interaction between your particle, and the other it's a totally free case where the particle self-organized without any external. So you can easily, I mean, each of you can tell, OK, this will be the free case and this will be the one with an external imposition where basically you don't turn a lot. But then suppose that you don't have access on such a long time series, you start to look at the thing on ten time, shorter time scale. This is the same time series, but just cut much earlier. You can start to doubt which is the correct one. Then you go 100 time shorter, you wonder which is the directed and which is spontaneous. Not totally sure. You can, of course, zoom, and maybe you can get some idea. You can use a little bit more refined techniques like auto correlation function of your time series, which I'm showing here.  And there is even a worse scenario where I'm not giving you two cases where I tell you this is spontaneous and this is directed. I just have one set of data and I have to decide if it's spontaneous or not. And remember also that the kind of diffusion in a group of N individuals, which perforce spontaneous collective motion, decreases with the number of individuals in the group. So the kind of noise becomes, in a sense, smaller and smaller, the kind of meandering and the persistent length growth. So short time scale is really difficult to tell by difference. There is an alternative way, which came from statistical physics and this is what I'm going to discuss here. And it's again based on the study of correlation function between fluctuations. So the main claim, which I'm trying to convince you, is that the nature of correlation between fluctuations equal time correlation. So here I'm talking about just looking at how a fluctuation in velocity or in the density at a certain point in your system correlates at the same time with another fluctuation at a distance r. Now, the nature of this correlation is radically different between the case of spontaneous collective motion and the case of collective motion, which is directed. In principle, if you have a system large enough and you are careful enough, you can be able to detect this kind of difference without accessing to a very long time series, basically looking at a few frames of your system. And this claim, which could turn out to be a powerful method to analyze data and to distinguish between the two cases, spontaneous and driven collective motion. Ok, now the story gets a little bit technical. I will try to keep some kind of not too complicated level due to the hour. The idea, you have already seen this kind of idea. When you, I start with spontaneous symmetry breaking. So there is nothing in the world which tells the group where they have to go. They just choose themselves. They talk one with each other locally. So they talk with their neighbors. They try, for instance, like birds to align their velocities and then they pick up a random one direction. And this is what physicists call spontaneous symmetry breaking of a continual symmetry. I don't know why there is written transition there. Sorry, mistake. That's spontaneous symmetry breaking. So you have already seen this drawing in many of this talk. Basically what happens is that since every direction is equivalent, once your birds, your particles pick up a direction, it doesn't cost basically nothing to change a little bit. And when there is a little bit of a fluctuation which brings you aside, nothing tells you this is wrong. Since you don't know where you have to go, you're just going around in some direction. This fact turns in the fact that the system is neutral to this mass situation. So you basically have this extremely long range correlation which emerge in your system, which you've seen in a lot of this talk. I mean, this is something basically you cannot escape if you have spontaneous collective motion. And this is true in a basically old system you can think of where you have spontaneous symmetry breaking, this continual symmetry and where there is nothing to tell you where to go. Another peculiarity, which I'm going to use in this method I'm proposing, is that in these systems the relative position of particles of neighbors, of beasts, of cells actually is coupled to the fluctuations. If they move, so if there is a fluctuation locally, it can make to sell diverge or to sell converge. So there is a coupling between the velocity and the density. So it turns out that this coupling makes also density fluctuation became long range. You can wonder why I saw interesting density fluctuation but the point is that I think density fluctuation are easier to measure. To measure velocity fluctuations, to measure velocity in the system, you need a little bit of tracking, maybe not a very long trajectory, but you need to identify for instance where the bird you have at time t goes after some milliseconds or some time anyhow. And this is not totally trivial why it is much easier to just find where in each snapshot of your experiment where particles are without knowing where they are going to be after a little bit. So in a sense density are very easy. Of course this theory has been worked out more than 20 years ago now. I am going to give a brief overlook but first the consequences you have already seen these kind of experimental data which came from Irena Giardina group in Rome. This basically tells one of the consequences I told you is that the correlation between velocity fluctuations for instance in a flock of birds either this spontaneous motion should be scale free but the correlation length is basically as large as the system size so it grows with the system size there is not a finite correlation length. And this is a proof that this kind of universe size applies. To bird there is a word of cautious that I want always to add since I mean their paper is clear but there has been some misinterpretations sometimes this has nothing to do with the bird being near a critical point where there is an order to disorder transition. The bird actually are highly ordered in this flock the fluctuation from order are extremely small but this is just a consequence of this spontaneous symmetry breaking which applies to the entire phase of collective motion so you don't need to be close to a transition. You can be terribly ordered with very small fluctuation and you still will see this kind of orientation fluctuation. Then there is something that is not speed scale free part but this is not pertaining to the stock but it doesn't have to do with order-disorder critical point in the sense of phase transition. Ok Velocity correlation now this consequence also means I mean this kind of property also means that if you go to Fourier space and this is something you already saw with Andrea Cavani's talk this for a number of reasons is more practical it's also a little bit technical but basically makes extremely easy to compute correlation function in Fourier space so basically what you have to do is just this operation you have to take here rj all the position of your particles in a certain snapshot you test the q represent wave numbers ok it's a vector in Fourier space you just have to take a different q typically small approaching the inverse of the system size and compute this sum where you take the exponential of this complex number which is the product between the q and the position of the births you take this sum over all the births then you take the model of square of this number reason what is simple you take an average if you can over a few different snapshot and you have basically your Fourier transformer correlation function ok and this is something which is rather simple to compute now these Fourier transform correlation function is some peculiarity like it's different in different direction if you look in different direction in Fourier space this is terribly complicated to measure even numerical simulation and I don't think it's simply accessible in experiments but what you can do you can average overall direction this improves your statistics and basically leaves you with the essential behavior of this object which is it is diverging with a certain exponent sigma as you go to smaller and smaller wavelength and I'm going to show you in a moment what it's doing and actually under some hypothesis this tonerantive theory tells you also which is the value of this exponent which is diverging there is a precise number for the criteria I'm going to show you it's of interest for physicists but it's not essential to discriminate between directed and spontaneous collective motion ok and then other consequence you have already seen today in your talk on bacteria is that this system are extremely sensitive I mean they have extremely large fluctuation in the local density ok and that's it this has been actually measured for instance this kind of things in a totally different system which is a system of epithelial cells we have measured actually this epithelial cells let's see ok when they express this protein here and you have seen this in the talk of Christina Marchetti also they basically have a transition to collective motion which apparently is spontaneous since when you go to measure these structure factor introduced before in density as a small q you exactly find this kind of divergence ok this is not extremely extended data which is due to the fact that we could for the moment only measure these on relatively small system of a few thousand cells but now we are trying to extend these but in principle this thing should go growing and diverging in zero as long as you increase the size of your system which means you are exploring smaller frequencies ok and also these other property which is connected to this one which is that fluctuations are extremely larger it means that if you go and measure for different sizes for the box in your system of particle and the fluctuation of this average these fluctuation are extremely large are larger than the square root of the number of particle which is what you expect in system which behave better which don't do spontaneous collective motion ok and again this is experimental data in this cell epithelial cell system and this dashed line is the theory ok so basically you have this kind of properties in this system this is spontaneous collective motion ok, I spare some details now we go to see what happens when the collective motion is not spontaneous but on top of this particle we choose a direction where is a preferred direction in space and to do this I put this kind of field H to exemplify I choose a V-check model and I put an external field of amplitude H in a certain direction, constant which tells on my particle as this direction is slightly better than the others ok and so basically I am pulling in a sense I am telling go that way before I anticipate the result of the theory then I don't think I will have the time to enter into the details but the results are the following what I told you so far about this long range correlation this divergence etc and actually I am introducing a cutoff in my system so if I look in real space I introduce a cutoff length which depends on my field above which this cutoff length depends on one over my field to a certain power certain power can be computed but this is again not so important and this telling me that my correlation are long range up to this length and then poof, they die and then the system realize the situation of the system realize that they are not spontaneous but there is some kind of overall direction the larger is the field so the stronger I am pulling my system the earlier this cutoff happens ok, that's video so this is something very clear if you go to Fourier space it's even simpler since a certain point when my q became small enough my divergence is cutoff and instead of growing as the wave number q goes to zero my system is going to go to a constant value ok, so there is a length scale or the inverse of a length scale Fourier space after which all that I told you doesn't imply anymore and my system behave decently and actually one can work out the expression a leading order in q and in the external field amplitude h for this structure factor ok, so before I had a divergence like one over q to some exponent this is just a pre-factor which depends on all the details of my system and not going to enter too much into that but now there is this correction which is linear in the field which tells me basically that when q became very very small and h is much larger than q this thing doesn't diverge anymore but it stops at a certain limit one over h ok I don't how much time do I have? 40, so ok maybe I can just give a flavor of how this thing is computed so this is a idodynamic equation of toner into theory so the idea as I told you is very similar to what you do in in Navias when you describe a fluid with Navias stocks basically find the important field of your problem which are connected basically to symmetry and conservation law so in this case you have the density since your particle are conserved at least on the time scales of the problem so the number of particle you have doesn't change and then you have the local average velocity since the essence of what your system is doing is breaking the invariance of all the direction in space and picking one so there is a breaking of the symmetry in your system so this is the script should be the scripted by a vector which tells you where you are going so these are the slow field of your theory and then you basically write this kind of partial differential equation which includes ok this is can look a little bit curious but basically includes all the possible derivatives to the lowest order which are compatible with the symmetries of the problem ok basically so you put everything so if there is not a strong reason not to put a term in this equation you put the term ok and then you can look so actually these are all adaptive terms these are all diffusive viscous terms there is a noise source since you want to equation in your system there is a pressure which is here and there is this magic term which is already seen which is exactly the term which luckily breaks the continuous symmetry and tells this velocity field to be non-zero, to be a value here which is v0 which is non-zero ok and this is basically the original theory of tournament 2 and there is a pressure which is here and what we do is just to add external field there is nothing particularly fancy you add this external field and you can go on now you consider the fluctuation in your system so small changes with respect to the average velocity and the average density of your system so you just see what happens if you put small fluctuation in your system you work out horrible equation which came from the previous one but this can be done so you go to Fourier space which is a standard technique you linearize with equation so you just consider at the beginning very small situations and you discard everything which is higher and basically at this point becomes a problem of linear algebra even if a little bit annoying and this leads you compute the structure factor in Fourier space at least to leading order in the so for small wave number and for small external field now technically you have to integrate over this time frequency to get the equal time structure factor you do all your calculation and you get this result here this is a prefector which I hope is correct and then this is this behavior you saw there is this one over q to some power the prefector in your field which act as a cutoff so the only thing is that here you have an exponent 2 which is what you get out of linear theory remember I basically said I consider all small situations now the original equation if you go back and look at also no linearities and this becomes a little less trivial to take into account and you can use basically dynamic randomization group arguments which is what also Andrea Cavagna talk about over the day and there are basically number of arguments to conjecture that to a certain degree that this exponent from being a q square became a q z ok and this is what gives you this characteristic length scale I show you before in the results ok and so you get basically this kind of final result you also average in all the direction as I told you in your life and you get this final result now we are going to test so you can test in numerical simulation these kind of things to start with I took again the V-check model I showed you before with an external field and what do you see here there are a lot of curves here is my structure factor here I have this wave number I told you so I measure as smaller as smaller wave numbers these correlation function in Fourier and I have different value of this external field they are pretty small compared to interaction but they already do the job and you see if I don't have an external field these things diverges like 1 over q to the z which is this line and the black dots seems to diverge as soon as I put even a small very small value of h at a certain point this term here became small and this dominates and so tends to have my system converge so basically my structure factor converges to a finite number basically the message is if you look at this quantity in experimental data you should be able now this is a very extreme case where I have an extremely small external field but look I don't know at this purple curve which is still small it's 100 of the interaction between particles the effect of the external field but you see that the purple line very clearly turns and doesn't grow anymore while the black line which is spontaneous motion grows indefinitively so basically if you're able to measure up to these small frequency which means up to these large sizes you will see a clear difference in the fluctuation correlation and you can say ha directed motion then you can test the value of exponents by doing some rescaling and more details which are more for physics you can check that the normalized theory works better than the original linear theory before doing Rg you can actually check which is simple just taking the value of this structure factor for q going to zero that what is left exactly scales like 1 over h and this is actually verified very neatly in the structure factor you can look again at the giant number situation which also the general friction get cut off if you take a box which is large enough at certain point they stop fluctuating in an anonymous way the number of particles in the box became larger than this cut off length introduced by the external field you see that the fluctuation becomes normal so this is possibly another way of measuring this kind of directed motion but they are strongly correlated ok ok this is a small detour there are other predictions which came out of this theory which basically tells you how the order parameter is going to change when you apply an external field the external field promotes to a certain extent order and this is telling you this theory can also tell you how the other parameter changes thanks to the applied external field this is basically what defines the susceptibility in physics and just adding this slide the susceptibility is diverging in the thermodynamic limit and there are consequences of this spontaneous symmetry breaking and I am just adding since recently the Nis Bartolo group actually happened to measure in a in a system of self propelled colloids submitted to an external flows which plays a role of this external field H had some measure of this response of the system to the external field which are compatible with our theory which predicts initially some kind of linear increase of your order parameter and after a certain value of the external field which depends on the system sides a growth with the exponent one third so this is already an experiment verification of another aspect of this theory and the last thing that I want to show you I don't have an experiment as I told you and the nobius objection on what I show you so far is you showed us the Vitchek model the Vitchek model in a sense is a wonderful model but it's a little bit dull particle just orient one with each other there is no steric repulsion there is no I mean the model is fully compressible so if you want to set this to people interesting in to send migration the cells are not like Vitchek particle cells occupy a volume they actually the kind of epithelial cells also Christina discussed are at the confluent limit where the pecking fraction is one or even slightly larger than one so can you still detect density fluctuations and correlation of density in this kind of system so I basically use the same model you have already seen in a few of these talks to call it collision on Vitchek model essentially it's a Vitchek model where you also have steric repulsion and I added an external field so not only my particle likes to go in the direction where they get pushed and this is what does the spontaneous ordering but also they have a direction which is better than the other which is given by this angle theta h so I'm just playing exactly the same game but in a model which is a little bit richer and this model actually has been shown to be able if you tune the parameters smartly enough to reproduce very closely the data of the cellular migration experiment I showed you at the beginning of my talk so the full dots are this model tuned and these open dots is the experiment I showed you before so I want to put myself in with a model which is reasonably close to experiment in cellular migration and to see the same thing and basically this is what I got again here I have a structure factor here I have a case where my field is 0 so the motion is totally spontaneous and I have this divergence as far as I like to go and here I applied very small field here the smallest is compared to the same constant between different particles essentially so 10 to the minus 2 and 2.5 10 to the minus to very small values but again you can see that if you look at one of this curve the green one for instance you see a clear movement towards a constant value so this is a clear sign of directed motion this is a clear sign of spontaneous motion if you want you can also divide sorry this should be q not h you can also divide by q to this magic power z I show you in the case of spontaneous motion you are flat in the case of directed motion you decrease this depends on how you prefer to look at the data so the point is there is a qualitative difference between these two kind of situations collective motion and directed motion and I believe that it is possible to observe in if you have large enough system if you have large enough number of particles to observe in real experiments and it can be used to discriminate for wild beast cellular migration and fish and other groups between these two cases and the recipe is very simple first of all hope that your moving system is large enough otherwise if you have 10 particles that's not the idea for you then compute the structure factor as I told you and all you need to know is the position of each particle or of many of the particle if you miss a few doesn't matter since this is statistical measure so if you have a 10% loss of your particle you can still survive now check the behavior of this quantity of loku if it is diverging you are spontaneous if you are constant you are driven that's the basic idea by the way these also work all the result I told you also work if your external field only affects a fraction of your particle so if you have a 10% of informed particle in your system since they know where is the nest they know where they want to migrate all these result apply it doesn't matter as long as you have a finite fraction of your particle which they know where they want to go all I told you is true so it's quite general there is one word of advice this is criteria maybe I mean the point is it could be that your system is not large enough to observe this kind of saturation of a structure factor this tells you if you are directed if you see a saturation and you are moving you are clearly directed it could be that if you see something it is just since you are not looking at a large enough system so if you have a very, very tiny preference for the direction maybe you need a larger system to detect so we cannot exclude directed motion with this method in principle but we can confirm it if we see this kind of saturation and the thing is moving that is going to be directed motion there is no doubt in terms list, but not last what we would like to do next and they would like to do this with the group of Roberto Charbino in Milano is to try a controlled experiment of course one could apply to a case where you know that there is chemia texis but an idea is to have one of these cellular migration experiment on some micro graded substrate so basically the idea is to take the substrate in which these cells are crawling and scratch it with parallel lines and the cells should be encouraged by this way to follow the parallel lines so we are introducing a preferred direction in our system and we believe that in this case we should observe the signature of directed motion so this is what we would like if we get some findings in the next months and that is basically the conclusion so my talk I have to thank my group in Aberdeen the black people is the people who collaborated to this kind of project and these are my external collaborators the people in Milano and John Turner in Oregon


Hello everyone. Sorry, it takes a bit so long here for me, but I'm ready now, so it's nice to see you all here, man. I'm seeing a couple of familiar faces, so that makes me a bit nervous. Okay, my name is Drep. I'm a web engineer at Tenna. Yeah, so where we make publishing easy or actually even fun. Today I'm going to talk to, I'm going to share to you part of how we make publishing somehow easy, but I have to warn you first that it's going to be a slightly sensitive topic. Who comes? Who are ready to talk about who comes? Not that kind of who comes, because we're going to talk about who comes? I mean who's in wordpress. That's what we're going to talk about today, not really the hook up that you know. Okay, so Dastun gave an overview in his talk earlier about registering a custom post type using an action hook. Did you see that? Did you see that? This is actually a follow-up talk on it. So Dastun, if you're here, thank you so much. So hooks. Hooks are part of the plugin API that refers to places where you can insert or change what wordpress is currently doing or outputting by default. To put it in a simple way, hooks allow you to intervene or possibly alter the result or execution. There are two kinds of hooks. There's actions and there's filters. Let's go ahead first with action. So actions are hooks that allow you to execute at a specific point during the runtime. This includes things like creating or initializing widgets, registering a custom post type or adding a menu. These are just a few of the many things you can do with actions. Filters on the other hand is the type of hooks that allow you to modify the result or data before it is used. You're allowing an external force here to contribute to the data before you use it further down in the execution. Yeah, so let's go right away to the anatomy of a wordpress hook. Actually, a wordpress hook can be called also as an execution point or a meetup point. By invoking this function, you are marking an area in your code where you allow others to hook up to process something. Anything hooked on in this action will be summoned or executed when the runtime reaches this execution point. The do underscore action is where it all begins. So when you see the red highlight there, that means it's required. It's not really part of the wordpress code or syntax. It's just my own desire to add that. So when you see the red highlight, that means a red flag. No, your edge is required. So the do action here is obviously a part of the action and action meaning. Next is the name of the action or event. And this is something you need to know in order to associate your function later on. It can be any name you want that makes sense to you. And as long as it has no spaces, as suggested by our wordpress on standard or best practices. Next one is the argument. And it's green. It's highlighted in green out because it's just optional. You can pass a single argument or more or even none at all. Whatever you feel like associated functions might be needing to do its necessary task. All in all, you can put it this way too. Hey, at this location where I put this do action, please execute all functions that are attached to this hook name. And also, please make these arguments available too. So you're kind of like commanding that part or execution point. I've got some examples here. These are with different implementation of do underscore action. We have do action with only the hook name as the parameter. We have another one with a hook name and a single argument or data. And the last one has hook name and three arguments. So that's how you can probably, that's how the variation of using do action. And those are all valid. Now that we know how to apply or mark a place in our code for those actions, let's look at adding an action. Adding an action is the act of hooking a function to an event where our event here is the hook name. To hook up, to hook up, not to the person, to hook up in our code, you need to simply invoke add underscore action. Then the hook name, in this case, it's my underscore action. This is the name of the action that tells what event your function should be associated with. And that function is the callback parameter. And it's mostly a function defined in your plugins and in your themes. It's basically the function that you would like to be processed. The next parameter is the priority number. Priority number is the number in which the function attached to an action are executed. If you haven't realized yet, we can hook up a number of functions to an action or event. Later on, you would want your function to get called first or in order for that to happen, you would add a lower number. Or if you want your callback function to get called later, you would add a higher number here and actually change the default. So if you're not going to add anything there, then we'll be passed to the add action function. And lastly, we have the argument count that simply identifies the number of arguments to pass to the callback function. And this should not exceed to the number of arguments given by the action. Remember that we are invoking or calling the due action earlier and there's arguments, those are only the limited number of arguments that you get passed to the function. By default, it's an argument count of one. I have different formats here of invoking and add action that we can look at. The first, let's start with how they differ in callbacks. The first one has normal callback format for procedural programming. We have an idea earlier by the talk of Jan Linux. He talked a bit about procedural versus object programming. The first example has a procedural approach. The second one is for a namespace callback functions. Namespace. So you don't mess with a namespace. And our last example here is if you are associating a class method as a callback. A class method needs to be in an array with an object instance as the first element followed by the method name. We also have different priorities in our example. Setting a lower number there would execute the callback earlier. That's the first example. Adding a 10 or no priority would be the normal order. In case that the hooks has the same priority number, they are executed in the order they were added in the action. And our last example has a higher number. That would mean this gets executed later. So if you want your function to be executed later and overwrite those coms before your function, you might want to add or to bump the number like 999 or go crazy like 999, or whatever. But as long as it's really higher. But make sense of it. Just control your function. How about if they have a different argument count? By default, you are passing one parameter which you may not use in your function. Sometimes in action, you may not use the parameter being passed in. The second is an example of passing in three arguments. And the third is actually valid. But really, passing 999 arguments to your callback function, that truly needs some code from you there. If you can, if you can add, well, if you can add, you can also remove. To remove an action, you only need to invoke remove underscore action and pass the name of the hook. Together with the same argument that you added the hook. Remember you added hook earlier, then you need to pass the same argument. It should have the same callback and the same priority number. So yeah, we have a couple of examples coming up. Who are Pokemon Go players here or hobbyists? Anyone? Hey, hey, don't, don't fool me. I mean, okay. Thank you to those who participate. I'm just curious, you know, but you might find some rare documents around here. So good luck. Okay, here we are trying to register a custom post side Pokemon. And registering a custom post side needs to execute early in the runtime. That's been talked about this earlier. So I'm just like, you know, repeating like some, some a bit of it. So we can make sure. So we need to make sure we hook up to the right action. This is very crucial WordPress that you need to hook up to the right action. There might be a lot of actions in WordPress, but you need to hook up to the right person I mean action. WordPress core has has a hook in place after the initialization stage where we can hook up our code. And that is the in it. So this is part of the WordPress core code. So they you can see how helpful, helpful documentation here because you can either go to WordPress quote code reference website to look for for to look at how to use it. Or you can simply rock on it right in your favorite ID. That's how I actually that's how I actually do most of the time. If I'm lazy to go to a website, I can just like go find a function right in the WordPress installation files, right? You can just like see some cool documentation. And so thanks to our core contributors who are like contributing documentation and make our lives easier. So now that we that we know where to hook, we want to we want them to associate our function Pokemon underscore in it, where we where we have our necessary codes to register the customer side. So yeah, in our Pokemon in it. So there you go. And viola you have a registered customer side by hooking into the action. He hooking into the action. There are tons of available action hooks in WordPress. There's in it, which is commonly used when registering a customer side and anything that needs to be executed earlier in the runtime. We have double P in it as well. We have double P head, which is commonly used to print third party script in the header as well as WP footer. If you'd like to place the script down in the footer, save post to process something after saving a post and add meta boxes, widgets in it for registering a widgets who doesn't like widgets. So now let's proceed with the filters. Let's take a quick look at the anatomy of a filter home. A filter will always return a value. That's the difference of this when it comes to the action hook. A filter will always return a value which then will be passed to another callback that is attached or that is hooked to the same filter. Or it can return back the value for use in the current page request. Here's where we are storing the final filtered result or value. Then we are officially calling the apply filter, apply underscore filters. This is what this is what allows the value to be filtered hook name is the first parameter as always. The record next parameter is the value being filtered. Of course, if you know if you want to filter something, you need something to be filtered. And an optional one or more parameter as always. Here are some implementation of our apply filters. You can simply pass the hook name and the value to the filter. Or you can add an argument as supporting data to hook's callback. Or you can add this directly as the expression in a conditional statement and see because since it can return a value. So there's something to validate there when you're adding it in a conditional statement. Adding a filter hook is pretty much the same as actually adding an action hook. This time we only have add underscore filter instead of add underscore action. And the rest has the same pattern as in add action. The callback, the priority number and the argument count. Still remember that? And it also has the same thing with removing a filter. And again, it must have the same argument. It's really important to have the same argument. Otherwise, the WordPress will read it as different than what you're trying to actually remove. Here's an example of filter hooks. We're filtering the post title here in the hope of making its title to be more Pokemon-ish. So again, it's Pokemon. So sorry. Yeah, so we will be using, in this case, we would want to use the underscore title that is readily available in WordPress and capture its value in your callback function. So here's a documentation of a black filters, that title that's already in place in the WordPress form. Then do the necessary operation from there in your function. And make sure to return the filtered value. So if the title, for example, is cat, then you would like cat to convert into meow or anything to be more Pokemon-ish, then you can do that. Or just the idea is you can always filter the title. Whatever your requirements in your project, whatever the requirements of your project would whatever needed in your project. Another example, if you're looking for a way to remove the CSS classes that are added by default when displaying menu in your template. You know, at first, when I work with displaying a menu, and then I feel like there's a bunch of classes being added there, and I'm not even using it. So I'm looking for a way to remove them for the semantic purposes of my HTML. So there's a nav menu CSS class filter is the way to go. You can add a filter. You can add a filter and assign a callback that that would return an empty string. That means no, that means no classes, no CSS classes. And that would get rid of those CSS classes for you. Or you can also achieve this with a helper function available in WordPress scores such as underscore underscore return underscore empty underscore string. I'm gonna feel like giving my address right. So there's available filter callback here return empty string, and that's right in the WordPress already. So you don't need to you don't need to write your own return return empty string callback for you to get rid of the empty string. There's already available WordPress. There's also return false return true return zero, and more of which are and more and a lot and a whole bunch more, which are intended as call filter callback function, provided by WordPress. So I suggest you find them like a Pokemon. No, they're pretty they're really rare, but you can always find them in our WordPress in the WordPress core. Again, there are tons that you can find in WordPress core. So please get to know them as much as possible and also utilize them whenever you can. We don't just end here by knowing how to add or how to remove an action. But there are also things you need. We need to keep in mind when working with hooks. A hook should have a descriptive descriptive descriptive name. It should clearly describe describe the event or location or data in a compressed format. For example, admin underscore in it. Yeah. So by seeing it, you'll know right away that whatever you hook up, whatever you hook up there would when whatever you hook up there would admin whatever you hooked up there will be will be fired when admin is initialized. Use hook to supplement an action, not the main action itself. It should not be dependent on the outcome of goods being executed from the hook. If a if any hook doesn't exist, it should not break your side at all. Knowing you can pass any number of argument doesn't warrant you to make all the things available to your callbacks. Only pass arguments that would make sense in the current context, and that would support the callback functions in accomplishing its task. And don't leave your developers friends hanging. Give them the best legacy you can ever leave behind by documenting every hook you have. And as you can see earlier, the admin in it, there's a documentation you can just simply read it and you know right away how to use it and what's the available argument that you can use. As important as knowing how to use hook is why we use it in the first place. Our plugins or teams can have codes spread all over the template, but hooks can can help you keep your logic separated. When working with a large code base deployed in a production environment, it's a very crucial moment to push features coming from a background of working with a VIP websites. Implementing a hook allows you to to more safely abstract a feature as a module or plugin and you can activate or deactivate it without breaking the site. And it makes your plugin more extendable, especially in a platform that becomes a very beautiful ecosystem. Thanks. And that's all. Thank you. Anybody has questions for you? Please be pretty sure. Anyone? No? Okay, maybe since we are late, maybe you can catch a little bit later. So yeah, thank you again. Our next