All right, good afternoon. Welcome back to your operating systems. So first bit of housekeeping. Course evaluations are out. I please fill them in because my job depends on it. So there's also a bunch of other programs at the university. You have a bunch of great TAs in the course. So if you wanna nominate them for things, you can. They would definitely appreciate that. I think there's other things so you can go ahead but please fill them out because that's like the feedback the university sees. So went to try and restructure the course so hopefully it worked out. Feedback helps new iterations of the course. Hopefully it's new iterations you don't have to see. So I like having you guys but I don't wanna see you guys again. So we'll try and pass the course. So with that, we're kind of winding down on the content. So today and tomorrow we'll have new content. Past that will probably just be review or open office hours because you'll probably be slammed with other courses. And may as well, we already did the heavy lifting at like the first part of the course where we didn't understand what the hell was going on but we have a pretty good grasp of it now hopefully. And yeah, I'll also do the early marking of lab six just so you can have a clear conscience about that. So I might do it today at some point and then definitely do it again Wednesday or whenever I can remember to run it. But today we are going to end up with end in allocators. So we talked about some general allocators before that you would do for malloc if you do happen to have to implement malloc but we'll talk about some allocators that are actually used. The slab allocators basically what you're doing in lab six your bitmap because everything's the same size and we'll see the buddy allocator because it's got a sweet name and also it works out quite well and the kernel actually uses it. So we were talking about the general problem where allocations are just random sizes that you have to deal with. Well, the buddy allocator is not as general as that. It actually restricts the problem. So whenever you request memory it gives you back a block in a size of a power of two which typically works pretty well for computers. And if you're something like the kernel or something like that where you control all your allocations you can make sure you allocate everything in size powers of two so everything works out nice. So typically this is how allocations work anyways. So the kernel uses that. So the only blocks the memory allocator gives you are of size powers of two. So it won't return you 37 bytes. No weird sizes are all gonna be powers of two. And if we restrict our problem to just be powers of two while we can do fast searching we can do fast merging and we can do things really, really simple gives us a nice algorithm and our only sacrifices were not as general as we could be. So the most basic strategy for implementing a buddy allocator is to use multiple lists. So before when we were talking about free list we just had one general free list and that free list kept track of how big the holes were what size allocations it can actually do so on and so forth. So for buddy allocator instead of having one general free list we have a free list for each power of two. So you restrict the request to be powers of two so if you wanna formalize it a bit more all the requests are gonna be two of the K where K is some number, some whole number or integer where it'd be zero up to N and N is the greatest thing you can support. So if capital N was 10 then you could support one kilobyte which isn't that much so typically it would be much larger than that. So no matter how many levels you have your implementation uses N plus one free list so it has a free list for each specialized size of a block and now our algorithm becomes really simple well if there's a request of two of the K well we just search the free list until we find a big enough block. So if the request comes in it's two of the K so it's two to the eight something like that while we would search the free list for the two to the eight free list where we know everything is like 256 bytes we would search through that if that doesn't have any free blocks which means we can't perfectly allocate it to a block then we're just going to search the next biggest one because we can't search the next smallest one. So we would search to the power of nine or 512 then if that fails we go up another level so another power of two, do, do, do, do until we finally find a free block and then what you do as soon as you find a free block you recursively divide it in half until it's the correct size. So if I find something that's like to the power of to the power of 10 and I actually want to the power of eight while I would take that to the power of 10 blocks split it into two to the power of nine blocks and then take one of those to the power of nine blocks and split it into two to the power of eight blocks and then use one of the two to the power of eight blocks. So the idea behind this is that since we're recursively dividing it and it's powers of two so each entry we take and we divide it into two, they're actually buddies so that's where the buddy comes from because they are beside each other like they're contiguous addresses so essentially you have a buddy so someone was broken apart with you, your twins whatever you want to think of it as and then for de-allocations the hardest part if you actually implement the free list that we saw yesterday is actually coalescing memory together so if you free something that's beside another free block and you want to make a larger free block well that involves a lot of searching sometimes and it's kind of a pain if you actually go to implement it while if you have this buddy algorithm and you de-allocate something well you can check if the buddy is also free so if you get freed and your buddy is free you know ahead of time that you're contiguous so you can just coalesce them back to one bigger block and add it to the free list that is bigger than you and you can also do this recursively so if that made his buddy available then you can coalesce it, go back up and merge everything back together so there's a recursive solution for doing the allocations and the de-allocations so this is what it would look like so for this picture we'll assume that our buddy allocator is managing 256 bytes so at the top so anything that has a dark background up there is just for illustration it's what the original block was and it means it's not used and it's not free it's just an illustration of what the buddy blocks look like so if it is managing 256K or 256 bytes well if it needed to do some allocations so here there's a natural allocation for 32 bytes and 64 bytes well at some point it would have had to broke apart this 256 into two 128's that are buddies of each other and then it broke apart both 128's into 264 and then in one case one of the 64's was broken into two so that it could actually do an allocation of size 32 so anything with a colored background means it's allocated and the program's actually using it for something so there's a 32 byte allocation that's in use there's a 32 byte block free that is of size 32 and for 64 bytes there's 264 byte blocks free and then one of the 64 byte ones is actually used by an allocation so if you were to draw this out too and had a free list so you would have a free list for every level so the free list for this top level of 256 it would have no entries because nothing is free for 128 it would also have no entries because everything is free for 64 bytes it would have two entries so there's 264 byte blocks available and for 32 bytes there's one entry available yep, yep, yeah so the starting configuration here would be that there's one you'd start off with one 256 byte block in the free list and then that's it so you start off with one entry in the free list the total amount of memory you're managing and then all the other free lists are just empty so whenever there's an allocation you can go ahead and recursively break it, yep so the 64 byte one has two blocks available because of this one here and this one so there's only two things available at that level because the blue box is like a natural allocation and then this one with the dark background was broken into two to do the 32 byte ones so 128 has zero available so it was broken apart into a bunch of 64 byte ones yep, yeah so ideally we would want the blue 64 byte one here maybe but this is after the programs run for a bit so you can't determine anything like that so you'd probably end up with a situation that looks more like this when you're actually running a real program but yeah, you're right ideally it would be allocated to the left so its buddy is already in use so if both of them got deallocated we could just go ahead and do it okay so now let's assume we have an allocation someone request an allocation of size 28 bytes well if someone allocate or request 28 bytes I can't do that because it's a we only deal in powers of two so the easy thing to do is well we round it up to the next power of two so what's the next power of two to 28? 32, yeah so I'll round that request up to 32 and I will start searching for blocks that are 32 and I'm going to lose four bytes due to internal fragmentation so because the allocator only deals with blocks powers of two so A, the wasted space is within a block so that would be internal fragmentation so in this case I would be looking for anything of size 32 because that is free and right now this I have a free block of size 32 so I don't have to worry about splitting buddies or doing anything like that I could just go ahead and make the request and I'll illustrate it in green so now the interesting thing comes in if we have another request for size 32 currently if I look if I had a free list beside 32 I have no 32 blocks free so I would have to look up to the next power of two so I would have to look up I see oh I have 264 byte blocks free so I should just split one in half and then I can make a 32 byte entry so I'd pick the one on the left for example I would split it into two 32 byte ones one would be left free because it's the buddy I just made and then we would fulfill that 32 byte request so any questions about that? Okay well then what will happen if we free the 64 byte block one then so which is the one in blue or teal or whatever you want to call that color yeah so I would free this one so if I free the 64 byte one well now it's free and as part of the algorithm you can check your buddy so it's like the buddy system or anything else that's called like that check if it's also free in this case it's also free so I would just coalesce them back to a big 128 byte block so now if a request comes in for 128 I can go ahead and fulfill that and that's where we would be at so any questions about how this works at all so yeah this is an easier way to coalesce memory everything has a partner everything has a buddy so you're essentially guaranteed that if the buddy's free well you can coalesce the memory back together because hey you're friends right you're twins so these are actually used in the Linux kernel so buddy allocators are used in pretty much every kernel I know of and it's because it has some very nice properties it's really fast especially compared to the general dynamic memory allocation where you have to worry about different sized free blocks maybe you have to search the entire free list to see if something is free here you can just check a list that's the right size and then know whether you have to go up or go down it's essentially logarithmic which we all like logarithmic algorithms so you don't have to check every single possibility you only have to check a log of possibilities so it also avoids external fragmentation because all the free physical pages everything's contiguous everything has a buddy so you're always guaranteed to be able to coalesce everything every block of the same level is the same size so you have no issues with that and the disadvantages is well there's going to be internal fragmentation so if your requests aren't in powers of two then you are screwed because you only deal with powers of two so you're going to be wasting some memory because every request we're going to round up so we're always going to have that but if you're something like the kernel or you implement this for your own program if you really really want to do your own memory allocation well you do all of your own allocations so if it's not a power of two you can just not do that you can choose to not do that if you're the only one using the allocator so the next one is a slab allocator and this is basically the approach for lab six so slab allocators take advantage of the fact that if all your allocations are the same size everything's the same fixed size well we can just allocate all objects from a dedicated pool and all the structures of that type are the same size so if every object is the same size one slot is as good as any other slot so it doesn't really matter and you could extend this so you have every object type has its own pool of blocks with the correct size so for lab six you essentially have a slab that keeps track of what blocks are allocated so it keeps track of everything of size block size which for you is one kilobyte and then there's also a bitmap that keeps track of all the inodes and all the inodes are the same size so all your inodes are like 128 bytes so they're all the same size so one slot in the table is as good as any other slot and you only need one bit to keep track of your inodes if it's used or not so if you extended this so your file system essentially just has two types of objects it has blocks and inodes but if you did this for your own program well you could do that same approach for every object that has the exact same size so you could just have a pool that I don't know say you just put aside a megabyte or something and all your objects are of size I don't know 16 or even just a weird number while you can just allocate objects in and out of that one megabyte of memory and manage that one megabyte of memory yourself just using something like a bitmap so you can kind of think of like a slab it's just like a cache of slots and all the slots are the same size so your inode table in lab six that's like your cache of inodes so there you essentially have 128 inodes of size 128 size so everything is the same size one thing is as good as any other slide so instead of a link list so you'll note in your file system there's no link list to keep track of allocations there's just a bitmap and what a bitmap is just so you have it here in the slides as well it's just one bit corresponds to one slot and zero means that slot is free and usable and one means that slot is allocated and you shouldn't use it so if you need to allocate something well you would just search that bitmap and search for a zero anywhere and if you find a zero anywhere you find where that bit corresponds to in terms of like inodes for example and then you would return that slot and set the bit to one and then for deallocations they're really really simple you just set one bit from zero to one and then you can just reuse that slot you don't even have to zero it out if you don't care about security at all or anything like that so that's what your inode table basically is and your operating system would actually like your kernel knows how to use that file system so if any of you are far enough in that lab where you actually mount your file system and can see it well it's just a normal file system so if you wanted to you can create files on there you could put you could copy some of your lab there it's not big enough to fit everything probably but you can copy files and everything and then look at your file system in that file afterwards and find that hey the kernel changed it because it added files to the file system because you edited a file there or something like that and you can also have combinations of this too so a slab could be implemented on top of a buddy allocator where you essentially use a buddy allocator to manage huge swaths of memory and then you treat each one you give each one like a bitmap and then slabs of different sizes so like this is what it could look like if you're using a buddy on top of a slab so say you have two objects of size A and B well what you might do is you might allocate a large slab that you use for multiple objects of that type and you might allocate that from the buddy allocator so you might ask the buddy allocator for a large amount of memory so say I want one megabyte I want two megabytes something like that and then you fit all of the objects on that big block of memory from the buddy allocator and you just have a bitmap and then from that bitmap you have have or may slots fill that so in this case the slab one A would be from the buddy allocator and then it would have a bitmap in this case it's just keeping track of four objects of size whatever and then we would have another slab that would be from the buddy allocator that has another four slots in it that would also have a bitmap to keep track of whether they are free or not and then you could have slabs B1 or B2 that have larger objects so they again would be from the buddy allocator and then you're managing the big blocks of memory you get from the buddy allocator so in this case I can fit only two and in this case the red ones mean that they're allocated and the clear ones mean that hey they're free you can use them so you might notice a bit of a weird thing here that hey if I have two slabs for A1 and A2 I should probably just coalesce them together into one big slab and I might also be able to fit another A here so instead of having eight in this example I might be able to fit a ninth one if I don't have separate slabs so that's also something you could do but you would have to do your own coalescing and manage an even bigger block of memory so it's just kind of up to you however you implement this so in this example we don't we have two separate blocks for A's objects and within a little slab here there's some internal fragmentation because again we used a buddy allocator for this so any questions about this? Cool. All right well that's even more memory allocations so we blasted through this so the kernel, the kernel has to do its own memory allocation but it doesn't have to go as general as if you have to deal with user programs that use malloc so what the kernel actually does is something called the buddy algorithm which is real world restricted implementation so it only deals with powers of two and keeps a free list for each individual powers of two and has very nice properties where because we just split everything in two and we have powers of two well everything has a buddy so if we need to merge and make a bigger block well if we split off from a buddy we know we can do that without any complicated checking or anything like that and then the next thing we saw is the slab allocator that takes advantage of having fixed size objects to reduce fragmentation the nice thing about that is if everything is of the same size well you don't have any fragmentation because that was one of our conditions for fragmentation and keeping track of the allocations is really really fast, really simple we don't need link lists at all we can just use a bitmap where just one bit keeps track of whether something is free or not so with that I will just stick around and we can work on lab six or I'll deal with any lab six questions or any other questions you have but just remember, pulling for you we're all in this together


What's going on Doof Squad? It's Logan here, we're back here again with another video and now today I'm sitting down on my chair because today we're going to be doing a new series, another new series and if you guys don't know what the series is, it is what you can see by the title of the video we're doing editing breakdowns of music videos because since I took a video course or a film course last year I've been doing YouTube for quite some time as well so I know quite a lot of stuff but last year at my film course I learned quite a bit about like editing transitions and all like just everything like that and I felt like I should do something like that so people can get like an eye on how much effort well how much more effort gets put into the music videos that um kpop idols really release well basically like the companies release but I am going to be going through idols new song hun and we're going to be going through a breakdown of that we're not just going to be reacting to it we're going to be watching it and when I see something we're going to pause it we're going to milk through it and I'll tell you guys what it is and all that stuff I just feel like it's going to be something fun okay like something a bit fun a bit different uh so yeah let's just do this okay so before even going on you can tell that there is a blur effect around uh soya on um the they probably use a camera blur and then did a mask and I did a mask that goes around like a oval shape around here uh because you can't really get that from a lens you can't get a lens that uh does that type of uh focusing so yeah anyways so let's get into this let's click on that beautiful as always just a jump cut no a jump cut oh oh I still love this song okay so back there you guys going to tell okay I didn't go back far enough right there I did a zoom out zoom out effect and I love these uh it's like it's basically you're doing a transform on the clip so when you do that it just like you can make it zoom out it's like got like kind of a warp type of um feeling to it and then there was probably if I can pause it right there was probably a blur on it or it was just fast okay 0.25 now this is just freaky okay so from what we saw from that it was just a it was just a zoom out there was no blur nothing like that it was just a zoom out from um soya on and then so she was like in the middle of the frame and then they zoomed it out so she was still in the center of the next frame for the next section for the music video so yeah that's uh definitely fake they wouldn't have her with real blood if you couldn't tell I guess I'm not too sure some people would think that's real blood but it's fake but oh wow those are nice nails and uh this is a focus from a camera and you can tell because it's like the oh let me get rid of that um like you can tell because of the edges the edges of her hand and it's like very very very well done so it's like from a camera with the focus on it uh so yeah that it's a nice weak focus touch right there uh she looks so beautiful here a minute now if we go back so there's definitely some lens flares there they uh definitely have a purple kind of screen over it uh as well just so it gives off that vibe um but yeah that's a lens flare uh if you couldn't tell they probably made that in after effects the lens flare uh there's a few there's a few edits in this music video which I freaking love but later on but yeah um as you can tell here there's a lens flare um and it's uh the the reflections off her nails is probably just the original light but uh the rest of that is just if you couldn't tell in this section here there's a lot of blurring in and blurring out on uh shuhua just look at that set man oh no i like legit look at that set that set is so good so good oh oh this is what i love like there's fade ins fade outs there's masking there's so much stuff in this section um with uki like legit just like we'll slow it down a bit we'll slow it down a bit so we can um see that we won't go 0.25 because that should be scary before but yeah if we go down to 0.75 so like there's fade ins there's also um masking like so she she's there she's actually there that's where she's standing but then they masked it out with the mirror and then bam she's there and then just like simple mirror that's just a simple mirror effect that you could do in premiere pro and then she was masked behind a wall here which is uh really well done it's a nice simple one and you can tell that there's a bit of favoring on the mask uh behind the wall or on the wall because you can still see her eye and stuff back there like this is a beautiful set and and like yeah there are mirrors but also you can tell when it's edited with the reflections um it's real nice okay let's go back to the normal because uh yeah there's not that much stuff of this a few seconds oh i love that now the smoke here it could either be it was done on set or they just added in a little bit of a smoke screen um and then uh i lowered the opacity on it for uh premiere pro or after effects or whatever software they use for editing um but it's uh it's a nice nice weave you can just download them on youtube um cloud glasses cloud glasses oh she's so beautiful man they're all so beautiful i love stuff like this so before it was like ah i love that so like with the movement they just like did the same they did a cut with her movement so it zooms out and it just looks so nice i've always liked that stuff and it's also within the beat so when um so he undoes it it just looks nice and like the cuts between clips just go so smoothly in this in this music video it's because it's because the way that they're cutting it if there was quite a few cuts here it's like so you guys focus on people's eyes when you watch a video right do like do you focus on their eyes or mouth whatever you focus on because for me i focus on people's eyes um when i watch a music video and um this is what most people do so when there's a cut for something the focus point that you want to focus on you've got to like kind of make it so that when the there's a cut the person's eyes that are focused on that one part so right now we're all focused on uki right here um probably with the next cut there'll be something right here that we'll be focusing on um see so she was like just like in the center she was in the center for the next shot but then you look up at her eyes here to see her expression and in the next shot her whole face is up there where her eyes were so it just like goes through smoothly and like her eyes are still on the same level from that shot but at closer distance for this shot if we just like go here so it's like it's like on the same level so you can quickly just like go to the next spot which is real nice like i just love stuff like that i try and do that with my videos i try and make it so when i do a cut that it's like a nice clean cut so you can go to the next part um and uh when is that that we get to the part that i really like it's just a nice simple masking anyways so let's just continue watching this see what happens next like nice smoke and see they use the smoke for so you have like focusing here you're like you're legit you're focusing in the center you don't know where to look so your eyes would just go to the center for this and then bam bam was there a mask there i'm not too sure let's slow it down um i'm pretty sure there was a masking with the smoke um speed 0.25 no so it was just a cut but since there's still smoke there um it still looks like it is a clean cut and since you're focusing on the center of the smoke we go back to uki's eyes but then there is the smoke that kind of goes over then which makes her eyes look more just like more like you want to focus on the eyes more see i like that i like that you couldn't tell it wasn't a mask but what they did was they used the walls they used the walls i don't know the pillars they used the pillars so like when that pillar i want to try i gotta go back to slow mo god damn it man we'll go 0.5 for this oh god damn it so like you start focusing on this because it's going past uki so you focus on that and then the next second when you're focusing on it like she's gone right now and then bam me unappears exactly where your eyes should be and like that's what i like it's just a nice it's like it's just a nice eye tracker um that i really like um it's just so nice so nice see see it happened again just the clean cuts so the clean cuts so we're focusing here and then she's there and then she's there again and then and then they want you to focus on the scorpion in the jar for this shot here instead of uki because uki is um blurred out at that and they're trying to get you to focus on that scorpion so like those clean cuts for like just from from here on with me on because oh that was actually a nice nice thing so you're like you're focusing on the eye there and then we go on to uki's other eye which is quite nice but then see you're focusing there focusing there and then you're focusing here it's like it's like in the same spot and then with the next shot she's back to here and then bam we're looking at the scorpion again like that it's just nice simple stuff like that that i like are you guys liking this video series i'm not too sure but anyways let's continue going on with this oh see that is what we like oh there was even a cut um behind soya look see it's like all black and then it goes to oh you saw a flicker at flickers flickers with her eyes but that is cool okay so me being the dumbest that i am i didn't really explain this i just said well that's so cool so what actually it is is that um you can just like add it's just like a clip of soya on and then they um resized it so it's small and they masked it they masked um the clip so it like fits in with um i forgot whose eyes that is but it fits into whoever's eyes that is and um then they make it so it like looks like it's uh reflecting and all that stuff because of the lighting that they used that they probably did this in um adobe after effects and then uh yeah so that's that's all that they did for the eye reflection shot and yet again when you guys look at this eye here you're focusing on soya and then what do you see next right here you see so young you see so young like legit right there when it first happens and then you track with her to go to here with the camera movement and now i'm assuming that this camera movement here where it goes like that was done in premier pro or the editing software that they use they just did a zoom in and then did a rotation at the same time and then snap back to the original shot um which was nice oh look at that this is where it starts happening where does have a look at this bam bam bam bam those are all masking transitions which i love so if you guys don't know what a masking transition is it's when let's say okay so what they do for the masking transitions is that for the shot there's just a pole there's just a pole at the end of the shot and then they just go past it and then at the end of the pole they'll just transition the next clip in behind the pole so they'll like mask it out if that makes sense so it's like it's like you're cutting something out with scissors that's basically how you think of it okay so you cut something out with scissors and then you you just want to make it so that the transition is just nice and slick and when they do it so fast here it's just so nice it's just so nice now this this here we all love this shot right we all love this shot here so this is probably done in after effects obviously done in after effects with the hologram uh there are i i don't know how to make that but i guess if i watch tutorial i could potentially easily make a hologram you'll just have to be in front of a green screen get lighting right and then it'll just all come down to the the editing with the lights the lighting and then getting the flicker effect on which isn't actually a flicker effect ain't that hard but yeah like you can make it actually you know yeah i could probably make the hologram but um yeah it's it's just a nice nice simple thing done in after effects which just looks so clean like this legit just looks so clean oh so good oh look at her eyes man i mean i mean it's just her eyes are beautiful now with that here with this transition right here now they could potentially this could potentially be a mask they could have done this shot just in case if something went wrong or something like that um there could be a mask on here they could not be i'm not too sure it could just be part of the shot where they go past the pole but they could it could be a mask so that it can go to the another clip so that it throws better or something i'm not too sure but uh when i saw this i did think about that but it's probably all just one shot this no masking but if they could use this for a masking if there was another shot that was better after it went past the pole if that makes sense um so yeah yeah and then after that we're focusing on this which is so nice i love that so much it's just such an easy thing to do you just get a square and then you just cut it in nice and like nice and tidy and then you just zoom in you can zoom in you've got to use the transform um effect to be able to zoom through it it's just like um BTS uh idols video where Jimin's mouth opens it's the exact same thing um but instead of just Jimin's mouth multiple times it's uh with that suitcase with the girls and like in different shots and then it gets to this clip here which you can see like i can you see it at the end i want to see yeah you can see it at the end you can see the clip at the end so it's just nice and smooth so nice so nice and i like that i like so it like flashes uh it flashes with them dancing in the background did you just oh wait let's let's slow down let's let's slow down speed 0.25 see it flashes with them dancing in the background i want to try and pause on it okay i can't pause on it but you can see right that's them in the background and yeah that's basically all i like those fast cuts yeah that's basically it there's this text can easily be done in uh after effects so yeah that was the editing breakdown for idols Han alone uh song what do you guys think about it you guys enjoy this if you guys did enjoy it then let me know uh some other music videos that you don't need to do this for i'll do this series like once or twice a week um because it does take quite some time to edit these video well i'm not really edit it will take take some time to record these videos so i need to have like the the time space to be able to record them um but yeah um let me know what you guys think what music videos you guys want me to break down next and uh also subscribe you guys that are new to the channel because there will be more of video editing breakdowns music really kpop music video editing breakdowns for you guys and uh there's also gonna be more of those um series on um koreaboo where i like read stuff down and like make funny videos of those there will also be the late to the party reactions where i react to videos that i have not reacted to yet so like old ones i can react to some like i i've i've never seen um like girls generation g i've never seen the music there for that but i'll listen to the song on spotify um so i can react to that music video and all that stuff so that's what late to the party is and then there's also the reactions for new kpop releases when they come out i react to those and uh yeah other than that uh there's gonna be all for this video you guys did enjoy and uh yeah other than that i just said and yeah other than that so many times but yeah other than that i hope you guys have a great day and just keep on smiling and i be your stuff


Hello everyone, I am Dr. Shreya Bhatt, JR-3, Department of Radiodiagnosis Narayan Medical College and I am going to be presenting Case Series on Fetal Anomalies, Ultrasonography a Boon for the Society. Introduction, Ultrasound is the standard and first choice method used for fetal anomaly screening. It is a real-time imaging modality that is easily available, cheap, easy to use and safe for fetus since it does not contain ionizing radiation. The second trimester ultrasound is commonly performed between 18-22 weeks of gestation. Historically, the second trimester ultrasound was often the only routine scan offered in a pregnancy and so was expected to provide information about gestational age, number, type of multiple pregnancy, placental positioning, pathology as well as detecting fetal abnormalities. Many patients now have several ultrasounds in their pregnancy with the first trimester and a nuclear translucency assessment being particularly common. The second trimester ultrasound is now less often required for dating or detection of multiple pregnancies but remains very important for detecting placental pathology. AIM, this case series describes the importance and imaging characteristics of ultrasonography for diagnosis of various fetal anomalies and congenital syndromes. Now case one, a 25-year-old primary gravidah female came to the Department of Radio Diagnosis for routine level 2 scan. She had no present chief complaints. Patient had abnormal hands and feet. These are the hands and feet of the female. She demonstrated lobster claw feet and hands with only two fingers. Bilateral fetal hands show absence of thumb, index and middle finger with visualized right ring, little finger both appear however fused. Bilateral feet show split foot with lobster claw appearance, similar to the mother. So the final diagnosis was ectodictile of bilateral hand and feet, Kashnaugibh Baur syndrome. Case two, a 25-year-old primary gravidah female came to the Department of Radio Diagnosis for routine antinatal scan. She had no present chief complaints. Ultrasound demonstrated a single intrauterine fetus as at 17 weeks of gestation by AC and FL with absent bony calvarium. The bony calvarium appeared to be absent hair and frog eye. Frog eye appearance was seen upon coronal section of the face. Spina bifida with cystic lesion in the lumbar region was also seen in all the three planes. This was the post-op image of the fetus after delivery. So the final diagnosis was enenkephaly with myelomaningocele, which is in the neural tube defect spectrum. Case three, a 20-year-old multi-para female came to the Department of Radio Diagnosis for routine level-to-scan. She had no present chief complaints. Bony defect was demonstrated in the occipital bone with herniation of the brain, occipital encephalocene. Also variable degree of absence of cervical vertebrae were visualized. Cervical vertebrae were not visualized clearly and the fetus had hyper-extended neck and head. Midline cleft lip was also visualized. This was the cleft lip and this is the 3D image of the cleft lip. This was image of the fetus after delivery with midline cleft and occipital defect, occipital encephalocene. So the final defect was enenkephaly, which is a neural tube defect spectrum. Enenkephaly is a rare neural tube defect with characteristic retroflexion of the fetal head as was seen in our patient. Cervical defect in the occipital bone, associated occipital encephalocene can be seen, which was also present in our patient, associated with spinal rachitis. Case 4. A 28-year-old multi-para female came to the Department of Radio Diagnosis for routine level-to-scan. She had no present chief complaints. She had a past history of misabortion six years back. Cystic lesion was seen with an enlarged posterior fossa was revealed that was contiguous with the widened fluid space between the cerebellar hemisphere. So this is the large cystic lesion. Absinthe, absence of vermis was also noted and spina bifida with a cystic lesion. This was seen in the dorsal region in all the three planes. This was the image of the fetus after delivery. This is the myelomeningocele, which was seen. So the final diagnosis was herniated dandy walker cyst with dorsal myelomeningocele. Case 5. A 32-year-old multi-para female came to the Department of Radio Diagnosis for routine level-to-scan. She had no present chief complaints. She had a past history of recurrent pregnancy losses. On the level-to-scan single ventricle was seen with absence of pharx in between and midline fused thalamine. So mono ventricle was visualized. Also this sagittal section shows a mono ventricle with a single coroid plexus. Apart from this cleft lip was also seen with cleft palate. This is the 3D image showing cleft lip and cleft palate. So clubfoot or CTEV was demonstrated in the same patient. So the final diagnosis was alobar holoprosensifeli with cleft lip, palate and bilateral CTEV. Typical findings of holoprosensifeli in its alobar form as it's supposed to be image in the first trimester, holoprosensifeli may be associated to other midline defects and many of aneuploidy such as trisomy 13 tau syndrome. Now case 6, a 25-year-old multi-pair female came to the department of radio diagnosis for routine antenatal scan. She had no present chief. Exial and coronal ultrasound images show fetal stomach. This is the fetal stomach in the thoracic area displacing the fetal heart towards right. So here we can see the fetal stomach is in the thoracic region of the fetus. Cerebral diagnosis, left-sided congenital diaphragmatic hernia. Congenital diaphragmatic hernia accounts for a small portion of diaphragmatic hernia. However it is the most common non-cardiac fetal intra-thoracic anomaly. Case 7, a 20-year-old multi-pair female came to the department of radio diagnosis for routine level 2 scan. She had no present chief complaints. Multiple small cystic spaces were seen in the right lung. These are the small cystic areas which were seen in the right lung. Right lung appeared ecogenic as compared to left. This was the left lung and this is the right lung. With multiple small cystic areas, left lung also appeared hypoplastic as compared to right. This is the side clip which shows multiple small cystic areas in the right lung. So the final diagnosis was congenital pulmonary airway malformation C-PAM in a fetus. Congenital pulmonary airway malformation C-PAM are multi cystic masses of segmental lung tissue with abnormal bronchial proliferation. C-PAMs are considered part of spectrum of bronchopulmonary foregut malformations. Case 8, a 25-year-old multi-pair came to our department for routine antinatal scan. She had no present chief complaint but she had a past history of intrauterine demise. Below are the ultrasonography images of fetal heart within which the left atria and ventricle appear hypoplastic not showing any vascularity on Doppler studies. So this is the hypoplastic left left heart, right heart appears to be normal, similarly no vascularity is seen on the left side. This side clip shows that there is a single great vessel, this likely pulmonary artery. No other great vessel is visualized in the vicinity. This image, this clip shows single ventricle and atria on the right side and left heart appears hypoplastic with a single great vessel. So the final diagnosis was hypoplastic left heart with single great vessel, spectrum of hypoplastic left heart syndrome, hypoplastic left heart syndrome which is a complex combination of cardiac malformations can be detected with prenatal evaluation with ultrason providing an option for pregnancy termination to the patients or intrauterine interventions may be performed if the patients which to continue the pregnancy. It also guides the clinicians to prepare for the postnatal interventions as and when required. Case 9, a 20-year-old multi-para came for routine level 2 scan. She had no present chief complaints. Antinatal ultrasound demonstrates a large protuberance from the anterior abdominal wall consistent with an umphalocene. The urinary bladder is exposed and opens through the abdominal defect with the bladder margins continuous with the abdominal wall resulting in a muco-cutaneous junction. Size of the extrafied bladder is variable here. So urinary bladder is herniating out through a defect. So the final diagnosis was fetal umphalocene with bladder exostrophy. Using fetal conventional sonography the presence of spinal defect in combination with the absent bladder and abdominal wall defect should allow the diagnosis of OEIS to be considered. The distinction from isolated bladder exostrophy umphalocene as in our case is important because clinical neonatal outcomes are different. Case 10, a 25-year-old multi-para came for routine antinatal scan at 22 weeks. She had no present chief complaints. Fetal urinary bladder is over-distended giving a classical keyhole appearance. There was bilateral hydronephrosis also noted. So this is the classical keyhole appearance with dilated urinary bladder and dilated urethra. So the final diagnosis was posterior urethral valve keyhole appearance. Posterior urethral valve is also referred to as congenital obstructing posterior urethral membranes, COPUM, are common congenital obstructive lesions of the urethra and common cause of obstructive uropathene infancy. Keyhole sign may be seen all ultrasound due to distension of both bladder and urethra immediately proximal to the valve. MCU was performed after the delivery of the same fetus who now presents with frequent urination and distended abdomen. In there was dilatation of the posterior urethra, this with bladder neck hypertrophy. Bladder wall had multiple traviculations. There was right-sided grade 5 vesico-uritric reflex demonstrated in the same child. Lastly, case 11, a 25-year-old female came to our department for level 2 scan. She had no present chief complaints. She had a history of recurrent pregnancy losses due to the same pathology. There is evidence of a narrow thorax with shortened ribs as seen here as compared to the abdominal circumference. The abdominal circumference was normal, but the thorax was shortened as compared to the abdominal circumference. There were associated limb shortening. All the limbs were shortened and multiple cysts were also seen in bilateral renal areas. So multiple renal cysts were also seen. So the final diagnosis was narrow thorax with shortened ribs and all four limbs which is exfixiating thoracic dysplasia also known as June syndrome. Exfixiating thoracic dysplasia also known as June syndrome is a type of rare short-limb skeletal dysplasia which is primarily characterized by narrow constricted thoracic cavity, cystic renal dysplasia and characteristic skeletal features. It is also sometimes classified as one of the short rib polydectile syndrome. We discussed 11 cases of various rare and common fetal anomalies diagnosed via antenatal ultrasonography. The use of ultrasound in the prenatal diagnosis of fetal genetic syndrome is rapidly evolving. Advancing technology and new research findings are aiding in the increased accuracy of ultrasound-based diagnosis in combination with other methods of non-invasive and invasive fetal testing. The use of three-dimensional ultrasonography in diagnosis of fetal clefts when suspected on two-dimensional ultrasonography greatly increases the sensitivity and specificity. Ultrasound can be used throughout the pregnancy to detect various fetal abnormalities. First trimester ultrasound is increasingly being used for knuckle translucency tests and also for early limited anatomical survey. Ultrasound in the first trimester has been shown to be effective in screening of aneuploidy conditions such as Trisomy 21. First trimester ultrasound largely focuses on ultras on knuckle measurements in assessment of chromosomal syndrome risk. However, second trimester ultrasound can identify much more specific defects that follow a different pattern for each genetic syndrome. Importantly, some fetal anomaly is more easily visualized later in the second trimester. Third trimester ultrasound can also be used as an enjunct to second trimester anatomical survey to follow the evolution of the identified fetal anomalies. The third trimester ultrasonography as a screening tool for fetal genetic syndrome however has limited utility. So finally the conclusion, antenatal ultrasound has evolved as a boon for society as it allows early detection and screening for fetal genetic syndromes which has improved the quality of life of many individuals. First and second trimester ultrasound provide information on possible fetal abnormalities. However, routine second trimester anatomy ultrasound is the most accurate at identifying structural abnormalities. Three-dimensional and four-dimensional ultrasounds are useful at junks in the diagnosis of select fetal anomalies and however, a normal ultrasound does not eliminate the possibility of a genetic syndrome. So these are my references, thank you.


I've decided to quit coffee for two weeks and here is what happened Hey, what's up, Greg here the founder of your own inception welcome to my channel If you want to achieve limitless performance then subscribe below to start a journey. Yeah, I decided to quit coffee for two weeks And today I want to share this experience with you I want to talk about what happened why I did it What are the benefits the side effects you can expect from doing this courageous decision or making it and at the end I will tell you also if you want to quit coffee as well how to do it in the best way possible So you don't suffer from the side effects that come with it So if you're ready, let's just begin now I've been drinking coffee for the past probably like seven eight years something like that And I really love coffee. I love the smell of it. I like the taste of it I like experimenting with coffee. I make bulletproof coffee. I you know prepared in different ways I bought a school and espresso machine I made different types of coffee like a Turkish way like I like the grease How would people do it in Greece and so on so I'm a big fan of drinking coffee. I'm not an expert, but yeah I really love it and one of the reasons I like it so much is because I really Love the benefits that you can get from drinking coffee and because of the caffeine that a coffee has But recently I started noticing some very weird stuff going on with me So after a couple of days of hard work, I Gradually increased the amount of coffee I was drinking during the day So I went from one coffee on one day to probably three in four coffees on Thursday and Friday and After a couple of weeks actually after two weeks of doing that What happened was I had a very severe crash and this crash repeated like every two weeks approximately So whenever I increase the dosage of coffee to three to four coffees per day I actually noticed that my body was just shutting down the I got this, you know severe crash I had some severe side effects like brain fog like Jerry like, you know, my heart was You know going wild and at first I wasn't really sure this is connected to coffee But then you know, I experimented a bit. I tried different things. I Optimized my daily habits and I figured out. Yeah, it was probably the coffee making those issues So as a consequence, I made this courageous decision and decided to quit drinking it for just two weeks and see what happens Now just before I tell you my experience I just want to tell you that we probably know about but if you don't coffee is a very powerful stimulant It is the most widely used stimulant in the world and while it is a very Effective energy booster it increases your attention It increases your energy and it provides a lot of antioxidants at the same time It can be quite dangerous if you over-drink it because you get dependent to it And by doing that, I mean you cannot Saturday without a cup of coffee And all of a sudden you're drinking two three four five cups of coffee per day And then you know, you're gonna get this massive crushed it, you know, quite often people talk about So yeah, you have to look at the caffeine that you get with coffee as a pretty strong Stimulant, it's not just like, you know a random thing that kind of makes you feel better But it's quite a strong stimulant. So you have to be careful with it So when I decided to quit coffee, um, I thought that was gonna be an easy task I mean what like two weeks without coffee. That's like nothing I can easily do it and honestly in the beginning. Yeah, it was quite easy Well kind of but then after two to three days without coffee.  I Was really unmotivated in the morning I had no energy like I usually had this routine in the morning Which included drinking cup of coffee, but then, you know, there was no coffee anymore and I switched it to tea Obviously I put in this. This is one of my favorite cups And I put tea in it to kind of a trick my mind. Obviously it didn't work I mean why did I expect? But anyway, yeah, I try a lot of things and after the first couple of days Really, you know, wasn't feeling well and I was starting to get worried like where this is leading to and and why am I so am I so Dependent to coffee. I mean, that's that's insane. I wasn't I wasn't aware of that before but after a couple of days So it was I think after a week or something Yeah, there were all the problems were gone basically when I woke up. I felt very motivated. I felt energized I kind of I didn't miss my I mean, honestly, I missed my cup of coffee because of the taste and the smell But I felt pretty good without it. I was definitely much more energized Also during the day, I felt much more energized also like after like eating a meal or something, you know I didn't have this typical need for a coffee and that was quite Encouraging basically I was quite positively surprised so after like seven to ten days all the side effects like the jittery the brain fog the lack of motivation and energy were gone and I felt extremely well and you know from day to day after like 15 days and you know just before I Drank my first cup of coffee again. Um, I was just feeling better and better and better And I was really shocked that um, you can feel so good even without, you know, your daily caffeine dose So yeah, and after the 20-day period, I didn't need my coffee anymore I didn't even think about it when I passed on coffee shops. Yeah, of course, I I Saw people drinking coffee. I smelled it and I you know, I some of the memories got back But the part of that, you know, I really didn't need it to be focused to have energy to be in a great mood Yeah, that was quite a positive thing. So look if you are suffering right now at this moment Like if you think you're dependent to drinking coffee if you cannot start working in the morning without a cup of coffee Then you probably are dependent and in this case, I would definitely recommend you making a two week detox from caffeine Not because coffee is harming you in any way like it's not really harmful But you're gonna feel so much better if you can do this now the best way to do it That's in my opinion is that you find an alternative to drinking coffee something that will Not smell and look like coffee But it will provide some of the benefits that coffee provides without the side effects in my opinion The best option is drinking Jiromata tea. You can find more information below about this amazing South American tea I switched to take like immediately. I drank like two to three cups of Jiromata every day It does contain some caffeine So keep that in mind, but very low amount and after like one week I switched to green tea I had a pretty strong green tea which again It contains a little bit of caffeine, but they're like a very little amount So there's nothing to worry about and you know, if you do this what's gonna happen is Yeah, you can expect to have a mild crash at the beginning This crash will probably include some kind of brain fog some kind of loss of motivation You won't be in such a good mood in the morning But as soon as you change this as soon as your body kind of gets rid of you know, all the caffeine that's hiding in it What's gonna happen is you'll regain your energy. You'll regain your focus You will regain your motivation and as soon as you do this as soon as you find like an Alternative that you can drink in the morning that is part of your daily habit your brain will get revived That's how I call it usually And it will kind of figure out okay now when I drink this cup of tea I need to perform before it was coffee now It's tea. That's fine. Okay, I can do it So yeah, you should you know kind of a feel much better in about a week ten days Something like that and what you're gonna figure out is you know with coffee You get this spike of energy and then the crash follows if you drink bulletproof coffee This is a coffee with MCT oil and some people put butter in it. I try to avoid butter But anyway, so what happens is that you have constantly those Spikes of energy and then crash falls a spike and crush After you kind of a get rid of coffee for like 10 15 days You don't have the spikes obviously and they're no crushes obviously, but your baseline of energy increases Okay, so you have more energy by default at least that's what I feel and I you know checked some other people doing the same thing What were their experiences and they kind of you know talked about exactly the same thing Sure, you're gonna still miss and if you love drinking coffee I mean you're gonna still miss the taste and the smell and stuff and I'm not telling you to start drinking coffee Forever, but you know just making such a detox every now and then can be very beneficial By the way guys, if you like this video, please press the like button below So the question is what did you after two weeks of drinking no coffee all it kind of depends on how you feel Now what I did is I drink one cup of coffee per day During the week so from Monday to Friday, and I try to avoid any kind of coffee during the weekend That's kind of a my strategy that I'm trying right now It works really well because I still get a lot of the benefits from drinking coffee And the crashes that I usually got are like non-existent at this moment Especially if I add some amp-sity oil to it. So if I prepare the bulletproof coffee So that's one thing you can do so you can by detoxing your body You can kind of a decrease the amount of caffeine You will basically need in the future on a daily basis to operate on how you want to operate So you can still drink your cup of coffee because you like the taste obviously and by avoiding coffee during the weekend You kind of make you know this weekly detox. I would call it the weekend coffee detox, you know And yeah after a while you will feel much better You will have more focus more energy the the spikes of energy won't be so so, you know It won't be so high and you know when the crash happens It's gonna be pre-mile crash if it's going to happen And I can imagine you can do this for weeks and weeks and maybe months, you know without having to do a longer detox So yeah, that's what you can do and I think you're gonna be very happy about it Once you go through it. So yeah, that's it for this video. Thank you for watching guys If you have any questions don't hesitate to contact me Don't forget to follow your reception on Facebook Instagram and hope to see you soon guys. Take care


Welcome to Learning English, a daily 30-minute program from the Voice of America. I'm Dan Novak. And I'm Dan Friedel. This program is designed for English learners. So we speak a little slower and we use words and phrases, especially written for people learning English. Coming up on the program, April 1st is the 20th anniversary of the start of Gmail. Some people thought the launch of the email program was a joke because of its release on April Fool's Day. Brian Lin has the story. Anna Matteo has the Health and Lifestyle Report on AI Chatbots designed to help people with mental health issues. Later, Andrew Smith and Jill Robbins present the lesson of the day. But first... When Google launched Gmail in 2004, it quickly grew into one of the Internet's most popular email services. At the time, though, many people thought the Gmail launch was a joke. This is because it was announced on April 1st, April Fool's Day, and Google's co-founders Larry Page and Sergey Brin had already established themselves as April Fool's Day pranksters. One year, Google published a false job opening promising job seekers a position at a research center on the moon. Another year on April Fool's Day, the company said it was considering adding a tool that would permit users to smell search results. Page and Brin later said Gmail's launch was the perfect April Fool's Day prank. This is because they felt the new offerings or features might have seemed too good to be true for users. Gmail launched as a free service. The new features included an increase in storage space up to one gigabyte per account. While that amount may not seem like a lot today, at the time it was considered very large. In 2004, for example, one gigabyte was enough to store about 13,500 emails. This compared to just 30 to 60 emails that could be saved with the then-leading email services run by Yahoo and Microsoft. In addition, the new Gmail included Google's search technology. This permitted users to quickly find specific emails, photos, or other data stored in the service. Gmail also introduced a feature that grouped multiple email communications about the same subjects. Former Google executive Marissa Meyer spoke to the Associated Press about her involvement developing Gmail at the company. The original pitch we put together was all about the three S's, Meyer told the AP. She explained that the S's stood for storage, search, and speed. Meyer helped design several products at Google before leaving the company and later becoming Yahoo's chief executive. When Gmail's launch happened in 2004, some readers began contacting the AP to suggest the news agency must have been fooled by Google's announcement. But that reaction by users was part of the charm of making a product that people will not believe is real, said Paul Buchheit. He recently spoke to the AP about his efforts to help build Gmail. Buchheit explained that the Gmail project was developed quietly at Google, which even gave the effort a secret name. He noted that at the time, he was just Google's 23rd employee hired. The company now employs more than 180,000 people. Although the Gmail launch captured a lot of publicity, it started out being offered only to a limited number of people. This is because at the time Google only had enough computing power to support a small number of users. When we launched, we only had 300 machines and they were really old machines that no one else wanted. That's what Buchheit told the AP. We only had enough capacity for 10,000 users, which is a little absurd, he added. But the account limitations actually led to more interest in the service and persuaded large numbers of people to request new Gmail accounts. At one point Buchheit said invitations to open a new account were selling for $250 each on eBay. Over time Google was able to increase the number of new Gmail accounts it established as it expanded its data centers. This move sped up the process of getting a new Gmail account. But the company did not begin approving all new Gmail requests until it officially opened up the service to the world in 2007. A few weeks later on April Fool's Day in 2007, Google announced a new service called Gmail Paper. The service was described as a way for users to print their email out on paper and send it through the regular mail. But this time Google was actually joking. I'm Brian Lin. From VOA Learning English, this is the Health and Lifestyle Report. The Mental Health Chatbot Ear Kick greets users with a friendly looking panda that could fit easily in a children's program. When users talk about anxiety, the panda gives the kind of comforting statements that a trained mental health professional, called a therapist, would say. Then it might suggest breathing exercises or give advice on how to deal with stress. Ear Kick is one of hundreds of free chatbots aimed at dealing with a mental health crisis among young people. But the co-founder of Ear Kick, Karen Andrea Stefan, says he and the other creators do not feel comfortable calling their chatbots a therapy tool. Whether these chatbots or apps provide a simple self-help tool or mental health treatment is important to the growing digital health industry. Since the apps do not claim to diagnose or treat medical conditions, they do not need approval from the Food and Drug Administration or FDA. The industry's position is now coming under more careful examination with recent developments of chatbots powered by artificial intelligence, AI. The technology uses a large amount of data to copy human language. The upsides are clear. The chatbots are free. They are available 24 hours a day and people can use them in private. Now for the downsides. There is limited data that the chatbots improve mental health and they have not received FDA approval to treat conditions like depression. Vale Wright is a psychologist and technology director with the American Psychological Association. She said users of these chatbots have no way to know whether they're actually effective. Wright added that the chatbots are not the same as traditional mental health treatment. But she said they could help some people with less severe mental and emotional problems. EarKick's website states that the app does not provide any form of medical care, medical opinion, diagnosis or treatment. Some health lawyers say such claims are not enough. Glenn Cohen of Harvard Law School said, if you're really worried about people using your app for mental health services, you want a disclaimer that's more direct. He suggested this is just for fun. Still, chatbots are already playing a role due to an ongoing shortage of mental health professionals. Britain's National Health Service has begun offering a chatbot called WISA to help with stress, anxiety and depression among young people. This includes those people waiting to see a therapist. Some health insurers, universities and hospitals in the United States are offering similar programs. Dr. Angela Skrinsky is a family doctor in the American state of New Jersey. When she tells her patients how long it will take to see a therapist, she says they are usually very open to trying a chatbot. Her employer, Virtua Health, offers Wobot to some adult patients. Founded in 2017 by a Stanford-trained psychologist, Wobot does not use AI programs. The chatbot uses thousands of structured language models written by its staff and researchers. Wobot founder, Allison Darcy, says this rules-based model is safer for healthcare use. The company is testing generative AI models, but Darcy says there have been problems with the technology. She said we couldn't stop the large language models from telling someone how they should be thinking instead of facilitating the person's process. Wobot's finding was included in a research paper on AI chatbots published last year in Digital Medicine. The writers concluded that chatbots could help with depression in a short time, but there was no way to study their long-term effect on mental health. Ross Coppel, of the University of Pennsylvania, studies health information technology. He worries these chatbots could be used in place of treatment and medications. Coppel and others would like to see the FDA review and possibly regulate these chatbots. Dr. Doug Opel works at Seattle Children's Hospital. He said, there's a whole host of questions we need to understand about this technology so we can ultimately do what we're all here to do, improve kids' mental and physical health. And that's the Health and Lifestyle Report. I'm Anna Mateo. Anna Mateo is with me now to talk more about this week's Health and Lifestyle Report. Thanks for joining me, Anna. Hi, Dan. Thanks for having me. So today's story is about chatbots essentially playing the role of mental health therapists. This presents some opportunities as well as some challenges. What are the problems with these mental health chatbots powered by AI? Some mental health experts have experimented with AI-powered chatbots and they have found that these chatbots tell people what to do rather than teaching people how to get better. Another problem experts are finding is that AI-powered chatbots often do not say the right things in emergency situations. What do you mean by emergency situation? Well, let's say a person is having thoughts of self-harm. Some mental health experts and even emergency responders are trained in how to deal with this. The chatbots do not seem prepared or able to correctly help these people. Okay, so we've heard some problems that may be caused by mental health chatbots, but how can they help people dealing with mental health problems? Well, some research has shown that they may be able to help people with less severe mental health issues by providing comforting statements, advice, or techniques for handling things like stress. And unlike an actual person, these bots are available 24 hours a day. As we like to say, 24-7, 24 hours a day, 7 days a week. But with the shortage of mental health professionals, these bots could be a good alternative, meaning another choice for some people. But as the experts in the story say, it is too early to determine whether these bots are actually effective or give good advice. It sounds like for now, people should not be looking for bots as a replacement for actual therapists and certainly not anyone with serious mental health problems. Thanks for coming on the show, Anna. You're welcome, Dan. Thanks for having me. English has launched a new program for children. It is called Let's Learn English with Anna. The new course aims to teach children American English through asking and answering questions and experiencing fun situations. For more information, visit our website, learningenglish.voanews.com. My name is Jill Robbins. And I'm Andrew Smith. You're listening to the Learning English podcast. Welcome to the part of the show where we help you do more with our series Let's Learn English. The series shows Anna Matteo in her work and life in Washington, D.C. Today's lesson has three parts. First, you will hear and repeat a few informal expressions Anna uses that are very common in American English. Next, you will hear Andrew and me having a native speaker conversation. Third, you'll get to practice hearing and listening to phrases that begin with the word what. We have a lot to do in today's lesson, so let's get started. Here's Anna in lesson 19 when she learns that she is going to make a new TV show. I have a new assignment for you. Your skills are perfect for a new show. A children's show. A children's show. That is awesome. When do I start? You start next month. Start thinking of ideas for the show. I have tons of ideas. I can show children what it's like in outer space or gray. Tons of is an informal way of saying a lot of. A ton in the units of weight used in the United States is 2,000 pounds, which is about 907 kilograms. So that's why a ton of or tons of means a lot or very many. Anna has a lot of imagination, so she has tons of ideas. I have tons of ideas. And there are tons of things we can talk about based on the Let's Learn English series from VOA Learning English. Here's some more examples with the expression tons of. So, Andrew, I'm going to Charlotte, North Carolina next weekend for a work meeting. But I haven't had time to plan my trip. And I don't really know what to do. Oh, don't worry about that. There's tons to do. There are more than one really good art museums downtown. There are major sports teams. There's an NBA basketball team and NFL football team, soccer teams. There's a very good symphony orchestra and a lot of good restaurants. You will have plenty to do. Yeah, I'm sure I will. Hey, I meant to ask you, could you help me move my office furniture if you're not too busy? Yeah, no problem. I've got tons of time. Speaking of the office, do you have any paper clips? Oh, I've got tons of them. Take all you want. Andrew, pretty soon our listeners will have tons of examples. That's true. I think they probably get the idea. But they should remember that tons of is a little bit informal. And it is used more in speaking than in formal writing. That's true. So how about teaching another informal expression? Well, how about, how about? Yeah, we can do that. Here's Anna and Jeannie in lesson 14. Anna needs some clothes to wear and a Jeannie appears and tries to help. Tonight, I am going to the theater with my friends. But I don't know what clothes to wear. Maybe this magazine can help. Her clothes are beautiful. I really want a friend like her to help me. I am Jeannie. You want help? I am here to help you find the right clothes. Awesome! How about jeans and a t-shirt? No! Jeans and a t-shirt are too casual. How about something more formal? Sure! When Anna says how about, she means, what if we try this? Awesome! How about jeans and a t-shirt? And when we speak quickly, we sometimes drop the ah sound from about and just say about. So it sounds like this. How about this? Or how about that? How about we listen to Anna one more time? Can you put on a jacket? Why not? I love the jacket! How about a hat? I think we can find tons of examples of people saying how about. I'm sure we can. But how about we do something else? There's something Anna says at the end of Lesson 19 that we could talk about for our native speaker conversation. Let's listen. I have tons of ideas. I can show children what it's like in outer space or in the deep, dark ocean. Those are great ideas, Anna. Please, go think of more at your desk. Yes. What other things can I show them? Mount Everest. Everyone has different skills. You have skills. I have skills. The important thing is to know what you are good at. Until next time. I think Anna has some useful advice. It is important to know what you are good at. Yeah. For example, last week I realized that I'm good at catering. You know, like setting up food and tables for a party. It's probably something I learned from watching my mother. Let's move on to our third topic for today. Phrases that start with the word what? Grammatically, these are called noun clauses. But you don't have to worry about the name. Just listen to the word order. You hear the word what? Then you hear a subject followed by a verb. Here's Anna again in lesson 19. Excited that she's going to have a new TV show. The noun clause is at the end. A children's show. That is awesome. When do I start? You start next month. Start thinking of ideas for the show. I have tons of ideas. I can show children what it's like in outer space. When she says what it's like, you hear the word what plus the subject it plus the verb is using the contraction form it's. So normally when we ask a question with words such as what or where, the verb comes before the subject like when we say what is your name. But if we put the what or where inside a sentence or statement, the subject and verb change places like this. I want to know what your name is. The words what your name is are the object of the verb no. So their job in the sentence is to function like a noun instead of a question. So that's why the word order is not like a question with what. It can be tricky to reverse the subject and verb order correctly. But don't worry. We're going to give you tons of examples. I can show children what it's like in outer space. And how about these examples? I can show you what I want. I can show you what I need. I can tell you what I think. I can tell you what I see. You can show me what you want. You can show me what you need. You can tell me what you think. You can tell me what you see. I can tell you what to do. I can tell you where to go. You can? Yes, I can. Go ahead. Tell me some more. I can tell you what time it is. I can tell you what the weather is. I can tell you what my cat likes to eat. I can tell you where my cat likes to sleep. I can tell you what it's like to watch the moon and stars at night. I can tell you what I went. I can tell you what I need. But I can't tell you what to do because that's really up to you. You know, I think that's true. You can't tell me what to do. But you can give me some good advice. Well, here's some advice for our listeners. Practice repeating the sentences you hear on this lesson of the day. And use the Let's Learn English series to find many more examples of things you can learn to say. That is some good advice. We hope you've enjoyed today's lesson of the day on the Learning English podcast. I'm Andrew Smith. And I'm Jill Robbins.