What's going on everybody welcome back to another breaking news story and all the tournaments that are being played in Melbourne right now Have been stopped for Thursday and no play will continue due to a test that came back positive for COVID-19 The Australian Open came out on Twitter to announce what has happened So here is from the official Australian Open Twitter account health authorities have advised us that a hotel quarantine worker has tested positive for COVID-19 those associated with the AO who quarantine at the hotel now need to be tested and Isolate until they receive a negative test they go on to say we will work with everyone involved to Facilitate testing as quickly as possible There will be no matches at Melbourne Park on Thursday an update on the schedule for Friday Will be announced later today and we also have a little bit of information on an email that was sent to all the players The authorities have advised that everyone who stayed at the Grand Hyatt between the 16th and the 29th of January We need to be tested and isolate until they receive a negative test result So there you have it players that were in quarantine during that time at the Grand Hyatt They will be under isolation for the next 24 hours They're not allowed to do anything players that aren't a part of that hotel will be able to go and do their normal thing They'll be able to train on the Thursday. They'll be able to do their normal thing But this affects a lot of players 500 to 600 players this is going to affect and it also affects the Australian Open That's supposed to start on Monday now that we've lost a day due to this All the tournaments are gonna be pushed back a day and the finals of these events players are gonna have to play two Maybe three matches in one day It's almost like we've had a rain delay and we've had to push everything back But we don't have any time after this week because the Australian Open starts on Monday So what will happen? I don't know. Let me know down the comments below Do you think this is gonna affect the Australian Open? Do you think it's gonna push the Australian Open back? What are your things gonna happen so players being suspended for a day? We'll come back Friday. Hopefully we get some tennis


Hello and welcome back to the craft box. My name is Brenton today. We're collecting the level 55 death spell Which is a virulent plague Are you pleased with the magic you got from Eric weird room?  He may need your help But I go and speak with him in north guard in grizzly. He may need your help, but I am sure he will make it worth the effort Okay, um, I'll let us head on over to north guard The rule relent plague I can never say that. I'm basically just a mess Weakness. Yeah, basically mess weakness. I think it is. Yeah, something like that Level 55. So good done this a while ago. I just chose not to I Don't know why but I did So, yeah, let us go and get this spell To Ravenwood To grizzle hind to the world tree Into bottle be Let's go Let go go go go go go go go But I'm bum Okay, grizzle hyme grizzle hyme. Yes Here we go. So here's storm and 8,000 health, which is kind of crazy So, yeah, let's talk to Eric and see what he wants us to do even though We know we have to um defeat someone who is storm and his 8,000 health Welcome back say I could use your help The room down it is clear that fate sent you here at this time I need help and can offer magic in return an evil Grendel named scab rock Stole my bag of rune spells and I fear he means to do terrible things with such power Can you go to his cave in Soudreland and recover my bag of rune spells if you do so? I'll gladly share my magic with you. Okay, I'll be back when I'm at Gabbrocks cave Okay, we are back More magic for me I might just eat you now though Okay, let us defeat you Luckily I actually thought that the minion would be myth but he's not so that is fantastic Um, we're gonna do that I'm gonna draw We are going to do you start off like no perps.  Whoa? What okay? Okay, okay, and Pure blade one and Blade two Okay Just waiting for him to storm lord and stun me before I hit Wouldn't be surprised if that happened blade three Hello Cyclops.  Who knows Who knows so many explanations for this blade for and We'll faint and hopefully kill both Yeah, we'll faint just because we can why not Faint Fizzle unlucky Fizzle unlucky No fizzle Good, okay, and here we go What's gonna happen Cracken Fizzle unlucky. Oh gosh Don't even have another one that is more than unlucky. Oh well, we will fortify. I really need some more accuracy Hmm Really need to get that accuracy. Okay, now we're like low health. That's not good Da-da-da-da-da-da-da-da Don't really want you Or you this is bad This is bad. I might have spoken too soon about this not being a scary battle. We were on 288.  Okay, 288. Okay good.  That's always good Just as well we hit We might actually be able to kill the boss, which is good Boop boop boop boop boop. I wasn't wasting those blades on just some minions. So yeah Okay, didn't quite kill but that's still did a lot. That's 3,000 health Nice Back to full health boy Yes, okay now we can hit Sure, we kill hopefully Who knows? Maybe if we crit Which we didn't do Unlucky. We didn't kill either. That is unfortunate Well, we're full health so not too big of a deal We are just going to Blade we don't need to but we're going to Oh Didn't do too much surprisingly and what's this one?   I have connection issues sometimes in this game.  I am in your debt. Let me reward you with a spell Okay, there we go that was Rulent plague which basically OP weakness for all enemies for three pups So yeah, that was good So yeah, thank you for watching them to leave a like and subscribe and if it was subscribe press the little bell So you know exactly when I post another video and remember craft outside the box


Hello friends. I'm Sanjay Gupta. I welcome you on Sanjay Gupta Tech School. So this is my website where you can find all Salesforce related videos. Those are created by me. So in this video, I'm going to discuss about SOQL in Epics. So I will demonstrate you various things. So here you can see all these points I will be demonstrating you with the help of Salesforce org. So first I will be telling you how we can write simple SOQL. So basically SOQL stands for Salesforce Object Query Language. So whenever you want to perform any query on standard or custom objects, then you need to write SOQL. So SOQL basically fetch the records which are available in a particular object, whether it is standard or custom. So we will cover these points one by one so that you can understand various things that we can apply on SOQL. So first I'm going to tell you how we can write simple SOQL. So this first point we are going to cover. So moving to the org, so I'm going to open anonymous window where I will be writing the Epics code so that you can understand how we can use SOQL. So first I'm going to create a list of account that is ACCList equals to a new list of account. So always remember whenever you query the records, you store them in a list because there may be chances that you are querying multiple records. So you need to write this. And whenever you write SOQL, you need to use these square brackets. Then try to use the commands that we are using in SOQL in uppercase. But as you know, Apex is case insensitive so you can write in lowercase as well. But best practice is we can write them in uppercase. So I'm going to select ID name. Now from should be in capital, then the object name. So this is a standard SOQL. So I'm going to select ID and name field from account. Now if I execute this query only, so it will fetch all available accounts. Those are available in the account object and will be stored in ACCList. So don't use queries like this. Apply some where clause or limit so that limited number of records should be queried. So right now I'm using limit two. So only two records will be queried and to show them, I'm using system.debar. So this ACC list. So in single quotes, this message will be printed as it is. And this is the list that contains the records which are queried from this SOQL. So this will be displayed on debug log. So now I'm going to execute this and I'm checking this checkbox as true. So it will automatically open the debug logs. So I'm executing this. Now I'm clicking on debug only. So here you can see two records are available. ID and names are available. So this is first record and then second record. So this way we can apply SOQL so that we can query the records related to any object. If you are using any custom object, then you need to use underscore underscore C as well. So here you can see I have two custom objects, students and books. Right? So let me open student. So you can see the API name of student is underscore underscore C and here I have fields. So yeah, for a student name, we have name fields. So I'm going to apply this now. So I'm changing this to student underscore underscore C will be student list. And here I'm pasting object name. So select ID name from student underscore underscore C limit to and I'm going to print student list. So this way you can use custom object in SOQL. So again, I'm going to execute this. So now two students record will be queried and their ID and name will be displayed. Right? So we have record types as well. So those are also displayed. So first student name is Sanjay and record type then another student name is Martin. So record type and ID. So these information are available for custom objects. So this way you can apply SOQL on both standard and custom objects. Right? So I hope you understood how we can write simple SOQLs. Now how to use SOQL for query editor. Right? So this is anonymous window. So here also we can execute SOQLs but here you can see query editor is also available. So here also you can apply SOQL. So you can write select ID name from account and let's say limit 10. So if I click on execute, yeah, so don't put semicolon.  So ID and names are displayed and 10 records are queried. So whenever you are doing development work, so sometimes we just need to validate like we have written correct SOQL or not. So to validate that you can write your SOQL in query editor and if it is executing successfully, so you can see the queried result will be displayed here. So here you can see query results total rows 10 are available with ID and name. So this way also you can execute your queries but if you are using anonymous window, so in anonymous window you can perform any other operations as well like you can create list variable and you can display the queried result that is stored in list. So through system.debug you can display that and you can see the debug logs as well. So in query editor we can apply SOQL only. So if you want to use other statements as well, so you can open anonymous window and then you can execute the codes. So now I'm minimizing this. So we will be using this anonymous window only. So now SOQL with conditions. So we can apply conditions as well. So let's say right now we are using limits. So I am removing this and here I'm applying where name equals to Sanjay. Right. So only those students information will be queried where name is equals to Sanjay. Right. So I am again executing this. So you can use where clause to put any kind of condition. So here you can see the student whose name is Sanjay. The record is queried automatically and it is displayed. So I hope you understood. So based on any field you can apply the condition. Then I'm picking one more thing from the bottom like use variables in query for applying conditions. Right. So I'm now putting this Sanjay in a variable. So let's say I'm using string variable student name and in this I'm assigning this value. So sometimes it might happen like you have some variables and you want to put that variable in the where clause. So how you can do that. So after equals to you need to put semi sorry colon and then the variable name. So if you are putting a name as a constant, then you need to put that in single quotes and without using colon sign. But if you are using variable. So in that case, if you're using variable, so you need to use this colon sign and then the variable name. Right. And variable is having this value as Sanjay. So right now name field will be compared with this variable. If a value matched, then the related records will be queried and those will be available into into this student list that we are printing. So I'm executing this. So clicking on debug only. So here you can see same results are displayed. Right. If I change the name. So let's say I'm choosing Martin executing this code. So here you can see Martin records are available and it might happen like if you put any name that is not available. So let's say Martin one. So this name is not available in student object records. So if I execute this, so you will see nothing is displayed, right, because nothing is queried. So this way you can apply where clause with the help of variables. So I hope you understood this as well. So this limit number of records return we already covered. So now I'm going to pick this null check null check on list return through SQL. So right now you saw I tried to search for the records where student name is equals to Martin one, but no record found. So the student list is containing nothing. So always remember whenever you are applying a loop on this list, let's say I'm applying a loop. So for student underscore underscore C S colon student list. So this way we can apply loop on the list queried. Right. So if this list is containing nothing, so we don't want to execute this loop so that unnecessary these statements won't be executed. So before starting this loop, you can check a student list dot is empty, right. So if this list is empty, so this is empty method will return true. But in that case, we don't want to execute this loop. So we can put not before this and we can put this loop inside this if right. So this way you can implement your statements right now if this condition is true, it means if a student list is not empty, then only this loop will iterate and you can perform operations here. And if list is empty, then this loop won't be repeating. So this way you can apply null check on the list written through SOQL, right. Now moving to next point that is count queried records, right. So we can count the records we queried as well. So for that, I'm going to use this thing count. And I'm going to create one diesel variable that is C. And I'm going to store the result into C. And here I am printing count equals to NC, right. So I'm putting Martin here and making this as comment, right.  So you can put count and then brackets here. So the records which are queried, they will be counted and the result will be stored into C. So here you can display that. And maybe if you are implementing this apex and calling it with the help of trigger, so in that case, we won't be using system.debug. Instead, we will be using the returned results to do some operation, right. So for demonstration purpose, I'm using the system.debug. So when you will be seeing my videos related to trigger plus apex. So there you won't be seeing this system.debug. So we will be applying some operation on the queried results. So now I'm executing this. So right now we are getting familiar with the apex. So here you can see count equals to one because one record is available there. Now, if I move here, so here you can see various accounts are available, which are starting with tech, right. So I'm going to count all these. So here you can see total seven records are available, which are starting with tech. So now again, I am converting it to account and here putting account where name equals to. So I'm putting tech here. So I'm just modifying this condition again name. I'm putting like. So I'm removing this variable and putting tech and then percent, right. So if name is starting with tech and having anything after this tech. So those records will be queried. So I'm checking name. So name should be starting with tech and having any other characters as well. So those records will be counted and they will be displayed. So right now we are not using these, sorry, this variable. So I am executing this. So you will see count will be displaying value as seven. So if I debug only, so here you can see seven is the count because the count records whose name starts with tech are total seven records. So this way you can apply this way close as well where we are using name like and then tech person, right. So, so we covered this thing as well now ordering query results. So ordering means we can we can apply ascending and descending, ordering whatever we are querying. So again, I'm going to use this ACC list. So I'm putting it here, ACC list, then ID comma name from account where, so where name is like this, right. And order by name. So by default, order by applies ascending order. If you want to apply descending, so you need to write this BESC. So right now I am going to display it in ascending order on, right. So let me show this ACC list and here I'm writing ACC list. So it will be executed. So now I'm removing this variable as well. So executing this. So you will see the result will be displayed in ascending order automatically. So first account is tech school, then tech school one. And if I go further, then you can see tech school two, then tech school three, tech school four. So this way in ascending order based on name, they are displaying. Now if I want to display these in descending order, so I can apply BESC and click on execute. So this way you will see the output will be available in the descending order. So tech school seven, tech school five, then tech school four. So this way you can see now records are arranged in descending order. So this way you can apply order by based on any field that is available in your object. And if you don't put anything after the field, then order will be ascending. And if you want to display them in descending order, you need to put BESC, right. So I hope you understood this as well. Then limit we already discussed, like you can apply limit 10, limit five. So those records will be queried, then use variables in query for applying condition this we already checked. Now next thing is query related records. So we can query records from parent to child as well, and we can query from child to parent. So first I'm going to cover parent to child. So account is parent for contact. So I'm going to fetch account and all the related contact with a particular account as well. Right. So for that purpose, first I'm going to object manager and I'm searching for contact. So whoever is a child, we need to open that and you need to search for the lookup or master detail. So on contact, you can see account is the lookup. So account is on parent side and contact is on child side. So we will be using this child relationship name. So whenever you query child records through parent, so you need to use this child relationship name in the query. So let me show you how we can do that. So select ID name, then bracket, then inside parenthesis, you need to write child query. So select ID name from context. So here you need to use the child relationship name. Right. So this is, this parenthesis will be querying the child records and here select ID name and after that we have from account. So this will be querying the parent record. Right. And here, if we go here on account, so tech school seven, if I go, so here you can see one contact is associated. So I'm going to put name equals to tech school seven and I'm removing all these things and I'm going to press enter so that it will be in new line. So now you can see, so this select ID name, this will be for account. Then in parenthesis, we are querying the child records of contact. So always remember that you need to go to child record, then you need to identify the lookup to parent and then you can search for the child relationship name. So here you can see, we are querying parent to child. So we are applying SOQL on parent and internally we are querying child records as well. So this is the parent record where name will be tech school seven and its related context will be queried automatically. Right. Now, how we can display the result or how we can iterate that. So we need to check this ACC list. If it is not empty, then we are going to iterate it. So this way I can iterate it. So results are available in ACC list. Right. So I'm going to use this. So if I display this complete variable ACC and let's say I just want to display the context. So ACC context. So here I need to write ACC dot context. The child relationship name will be having the details related to contact. So one account will be available in this ACC and the related context information will be displayed on me. Right. And I'm putting this here. So this will print whole details, including account and related context. But while iterating this loop, we are just fetching the contact details only. Right. So two results will be displayed. So now I'm going to execute this. So here you can see this is ACC list, which is showing on the account details, but it is having context as well that you can see that is displayed in with the help of line number 10 system dot debug. So contact details, contact. So this is the account ID that is available on contact. So if you match these two IDs, which is displayed in first output and account ID, which is available in second output, both are same. Right. And this is the contact ID 0, 0, 3, 2, W, then 0, 0. And this is the contact name Sanjay Gupta. So if you see the related context, so here a contact name is Sanjay Gupta. So only one contact is available here. That's why one contact is displayed. Right. So let me create one more contact here. So here you can see account is automatically populated. So I'm putting Vikas Gupta and saving this. Right. And let me execute that again. And this time I am fetching phone as well. Right. So whenever this ACC dot context will be displayed, so account, sorry, contact ID, contact name and phone, all these information will be displayed. So this time this tech school seven account is having two related contacts. So two contact details will be displayed. So again, I'm going to execute this. So here you can see in first output only account details are displayed and then contact one name Sanjay and phone. Then if I scroll, so here you can see name Vikas Gupta and phone. So these details, so two contacts are related. So both are displayed here. Now, if you want to apply some logic on these contacts, so here you can apply one loop as well, one more loop. So what you can do, you can write contact on equals to ACC dot contacts. And you can apply this. So this ACC is having one account details and that account may be having related contacts. So we are fetching those contacts through here as contacts will be contacts can be more than one. So we can iterate them as well here in this nested loop and you can apply any logic here. Right. So this way you can apply loops as well. So here in this you can see we can apply SOQL for loops as well. So right now I am wearing this and storing into a list and I'm using list here, but later on what you can do, you can cut it from here. You can cut it from here and you can put it here as well. So this is also correct. So whatever you are querying will be available one by one in ACC. And then if you want to fetch the contacts, so you can write ACC dot contacts. So this way you can also apply SOQL in for loop. So I hope this thing you understood. So now next thing is one more thing is remaining that is querying parent values from child. So let me explain one more thing like if we have custom object and we want to apply parent to child relation in SOQL. So how we can do that. So here I have two objects, student and books. So student is parent and book is child. So let me show you that if I search for book and if I go to the field, so here you will see a student look up, yeah, here it is. And if I open this, so now I am on book object which is on child side because it is looking up to student. So that is on parent side. And here you can see child relationship name. So I need to use books while querying the records. So I will be applying the SOQL on student and through student I will be fetching the related books. So let me apply that as well. So here I am putting student underscore underscore C. This will be student list. It will be student. So ID name will be same then for book. Let me search some fields for book as well. So what we can fetch, we can fetch book name ID. Right. So I am leaving them as it is phone I am removing. And here we need to write books that is child relationship name from student where name equals to Sanjay. So the student name should be Sanjay. And for that Sanjay student, whatever books, records are related, they will be queried. Right. And here I am, so let me put this here so that you can understand this also. So I am putting it here. Right. Removing the statement. And this will be printing the student list. So yeah, no, this won't be executed because we are putting query here. And this time, this if condition is also not required because we are putting SOQL in for loop. So if you are putting SOQL directly in for loop in that case, that if condition is not required because if nothing is queried, so this loop won't be executed. So I am removing this loop as well. So we are just going to print book details. So student books details. And here I am using student underscore underscore C STD. And here I'm writing STD dot books. So this way you can modify your query. So we are querying student details as well as the related book details. So this is parent to child query and the results will be available into STD. So through STD, you can fetch the parent details. And if you write STD dot books, so in books, our child records will be available. And further, you can apply a loop as well that I demonstrated already like account contact relationship. So similarly, you can apply that loop as well. So now I'm going to execute this one error. Okay, so, okay, here one thing you need to remember. So earlier we were working on standard objects. That's why we used contacts only. But right now we are working on custom objects. So with child relationship name, you need to append this underscore underscore R as well. So now I'm executing this. Okay, so here also you need to put this so books underscore underscore R. So this thing is very important. So if you are working on standard objects, then you can use child relationship name as it is. But if you are working on custom objects, then for child relationship name, you need to add underscore underscore R. So this thing is very important that you need to remember. So now I'm executing this. So here you can see student book details. So let me go to student records. And I'm opening Sanjay. So here in the letter, you can see two books are available. So let me open, yeah, two books are available. So if I open this, so here you can see book 005 and book 006, two records are valid. So this way I hope you understood how we can apply parent to child query on both standard and custom objects. So this thing is very important. So whenever you will be implementing your apex, so these queries will be required. So I hope now you understood. So one more thing is remaining now child to parent. So I will be demonstrating it for both standard as well as custom. So right now let's understand it for custom first, then I will be applying it for standard objects as well. So I'm removing all these things. So what we need to do now we need to apply query on book. So, so this way I'm modifying it. So this time we have book list. So I'm removing these. So equals to select ID name. And now through this book, I need to query student name as well, right? So whatever book details I want to query, I just want to fetch a student name as well like which student this book is associated. So whenever you are applying child to parent SOQL, so you need to put this thing student underscore underscore R. So again remember, these are custom objects. So whenever you are querying from child to parent, so for parent referencing, you need to use student underscore underscore R then dot and then field name, right? So field name for student name. Yeah, so here it is name. So I'm using it. Then you can apply from book underscore underscore C where name equals to, so let me take a particular name. So I'm taking this name B dash 0005 because it is associated with Sanjay. So I'm putting it D dash 0005 and then system dot debug book list plus book list. So now I'm going to execute this. Yeah, so it is showing some error. Yeah, currently this I need to just remove. So it is executed opening debug only and here you can see it is showing book ID, book name and student name. So that name field field is containing ID. So it is showing that thing. So if you want to fetch any other, if you want to fetch any other field of students, so let me search, let's say we want to show roll number as well. So what you can do, you can write student underscore underscore R dot this roll number underscore underscore C. Let me execute this. So let me check. So what is happening? Basically, we are creating name and roll number. So if we are printing this book list as a whole. So those name and roll numbers are actually not printing. So what we can do, we can iterate a loop. Let's say for book underscore underscore C, then here we can apply book list and inside this loop, you can apply a system dot debug student name. You can write B dot student underscore underscore R dot name and you can copy this, paste it and for student roll number from here you can copy this and you can paste it, right? So now here you can apply if condition as well so that you can check book list is empty or not, right? So we can apply that as well. If not, book list dot is empty. So if this condition will be true, then this follow will be executed. Otherwise not. So I'm putting it here inside if, right? Now if I execute this, so you will see name and roll number will be displayed. So in the top you can see only related student ID is available. So we are querying from child to parent. So parent record ID is available here and then if we iterate that in loop so that we can fetch the name and roll number or other fields as well.  So one by one each book records will be available into B and then you can apply whatever logic you want to apply. So B or you can say book list is having a book ID, book name, then related student name, related student roll number. So all these things are available one by one in this B variable if we iterate the loop and then you can apply the logic and later on also you can apply this whole SOQL here as well. So if you do this, if you apply it here, so in that case you don't need to write this and all the things, those you are querying like related to child record as well as to parent record you can iterate in the loop. So in this case we don't require this, right? So this way you can implement it. So I hope now you understood how we can apply a child to parent. Now one more thing if you want to apply this on standard object, if you want to apply this on standard object, so let me do that also. So I'm removing all these statements. So I'm just modifying this. So what I can do here I am writing account. So I am using child as contact and parent as account. So account name, I'm querying, removing these from contact where name equals to Sanjay Gupta and I'm removing this because I have one feed account.name. So here I can write account.name. So here you can see account name, right? So remember that when we were using custom object, so we used underscore underscore r but this time we are using standard object. So we don't require underscore underscore r here and we can directly query the fields which are available on parent side while querying the child record. So if I execute this, so the contact whose name is Sanjay Gupta, so that context related accounts will be displayed. So clicking on debug only, so here you can see five record matched. So for four there is no account associated with the contact but for one account is associated so that name is displayed here. So this way you can apply child to parent query. So I hope now you understood each and everything that I demonstrated in this video. So I hope you understood whatever related to SOQL I explained and demoed in this video. So do apply all these things in your org as well so that you can learn like how we can use SOQL in APEX in Salesforce. So if you want to watch more Salesforce related videos, so you can go to this website and there you can find links of all the videos that I created. So thank you for watching this video.


Hey, Psych2Goers, welcome back. Before we begin, we'd like to mention that this video is for educational purposes only. Please do not diagnose yourself or others. Also, please note that the official term for skin picking disorder is exhortation disorder, the official name used by the DSMV. With that said, let's begin. We've probably all seen people pick up their skin before, whether it's at a pimple, a scab, or a dry, flaky skin. However, not everyone who picks at their skin has a serious problem. So, what differentiates normal skin picking from abnormal skin picking?  This video will discuss the diagnostic criteria of skin picking disorder, or exhortation disorder. According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or the DSMV. Number one, the person keeps picking at their skin. People with skin picking disorder repeatedly pick at their skin, often for hours. Skin picking can be automatic. For example, a person could be talking on the phone and be picking at their skin without even realizing it, or it can be more focused, where the person is well aware that they're picking at their skin. Nevertheless, as a result of the skin picking, the person develops scabs and wounds and feels the need to cover it up with clothing or makeup. Number two, the person has tried to stop picking at their skin. The criteria also requires the person to have repeatedly tried to stop picking at their skin without success. They may have reached out to people to help them stop as well. The potential reason why they find it difficult to stop picking at their skin may be because it gives a sense of relief and feelings of satisfaction after picking at their skin. In short, if it makes them feel good, it's hard for them to stop. Number three, skin picking causes clinically significant distress in other aspects of the person's life. Skin picking causes the person to experience distress in other areas that matter to them, such as their ability to focus in school or at a workplace. The person could feel shame, embarrassment or humiliation as a result of the way that they act. Examples of clinically significant distress can include avoiding all forms of social contact because they worry about what others might think about them picking at their skin in public or like avoiding classes because they're worried about not being able to resist the urge to pick their skin in front of other students. Number four, skin picking must be differentiated from other disorders. A common criterion in the diagnosis of other disorders in the DSM is that the disorder should be distinctly different from other disorders. In this case, skin picking cannot be attributable to other disorders. In particular, skin picking disorder needs to be differentiated from other experiences such as delusions in a psychotic disorder, efforts to improve appearance in body dysmorphic disorder, stereotypes and stereotypic movement disorder or obsessions and compulsions in OCD. And there you have it, the diagnostic criteria of skin picking disorder as described by the DSMV. For someone to be diagnosed with skin picking disorder, the behavior has to be frequent to the point of affecting their performance in everyday life and has to cause them distress. They also have to have attempted to stop picking at their skin and these symptoms must be distinguished by symptoms of other possible disorders. Have you or someone you know been diagnosed with skin picking disorder and would like to share your experience? What other psychiatric disorders would you like to learn about? Let us know in the comments below. Give this video a like and subscribe to Psych2Go if you enjoyed this content. And as always, thanks for watching. We'll see you next time.


Officers of the Zamfara State Police Command have arrested or rescued rather full-female victims of kidnapping after three weeks in captivity. The Command's Public Relations Officer, S.P. Mohamed O'Shea, who is narrated, the women were kidnapped in Bilbis, community of Safir, local government area by suspected armed bandits. The Zamfara State Police Command deployed police tactical operatives attached to Operation Restore Peace in Zamfara State to the area with a mandate to rescue the kidnapped women, Hill and Harteen. The operatives acted on credible intelligence which led to the successful rescue of the kidnapped victims. All the victims were medically treated at the hospital and later debriefed by the police before being reunited with S.P.A. families. Click the notification button so you get notified about fresh news updates.


Hello everyone, welcome to the next lecture in the course remote sensing principles and applications. Today we are going to continue discussing about the spectral properties of various commonly occurring earth surface materials. In the last lecture we discussed about the spectral reflectance property of water and what factors will influence the spectral property. Today we are going to start with the concept of understanding the spectral reflectance of snow. So before moving on to understanding the spectral reflectance of snow, we will just get introduced to small introductory concepts about snow. So snow is nothing but a collection of ice crystals or ice grains, air, water and other contaminants mixed together. Everything like ice plus air, whatever everything mixed together will form like snow pack. The snow occurring at different places in the globe will vary a lot in the size. Size means the grain size, how big or small the grain sizes, the density or the packing of the snow, the amount of contaminants present etc. So snow exhibits a very high amount of variability from place to place and time to time. And also compared to any other material in the globe, snow has the highest or brightest reflectance especially in the visible band. Like we might have experienced this, some of us might have seen snow really or some of us might have seen it at least in televisions or movies which is snow appears extremely white and bright in the visible domain. So snow is like the brightest among most other occurring earth surface features. And also snow or its particle size and everything this will be under like constant evolution. That is when snowfall occurs today after a certain period of time, snow will undergo some change like it may become more dense, the grain size may increase or some contaminants may get added to it etc. So snow shows high degree of change in both spatial and temporal domain. So when we want to understand the spectral property of snow, we should realize that the final reflectance or the final spectral property we obtained from snow is an integrated effect of the ice grain, air mass, water molecules and other contaminants mixed together. So it is not only the spectral reflectance of ice but also like mixture of several different things that could be present in the snow. So some of the factors that influence the spectral properties of snow are first thing is the grain size, how big or how small the snow grain sizes, age of the snow. Most likely snow will become larger in size as it ages like more and more accumulation may fall, it may grow larger in size, hence snow age will influence it. Then presence of any liquid water molecules within the snow will affect the spectral property of snow. Then the solar zenith angle in which angle the sunlight is falling on snow, then presence of any contaminants may affect the spectral reflectance from snow and also the thickness of the snow pack, whether the snow is really thick or it is like shallow etc, will all these things will have the ability to change the spectral property of snow. First we will look at the general spectral reflectance curve of snow and how it changes with grain size as well as the wavelength of observation. First if you look at this particular slide, here we have plotted two curves, one is the spectral reflectance curve for fine snow that is snow with fine grains or smaller grain size and then this orange curve is the spectral reflectance curve for snow with larger grain size. If you look at them, first what we are observing is for both the grain sizes whatever be the grain size, the general pattern is invisible up to say 0.7 micrometers. Let us draw some line somewhere here, up to this the reflectance of snow is extremely high in the order of like above 90 percent. So the reflectance of snow is extremely high in the visible domain and also up to say 0.8 micrometers. Only after like when the wavelength enters NIR band after it crosses the 0.9 micrometers, the reflectance begin to decrease drastically and after crossing this 1.4 micrometers the reflectance is quite low in compared to the reflectance in visible. And hence here also we can divide the reflectance into visible and IR bands. I generally make it as IR which comprises both NWIR and SWIR. So highest reflectance occurs in visible band and in NIR the reflectance begins to decrease and it decreases overall we can observe the trend is decreasing as the wavelength increases the overall trend. So in general the reflectance will decrease in increase in wavelength in the IR domain except these 2 like small peaks almost the overall trend of reflectance is coming down or decreasing as the wavelength increases starting from NIR band. So this is the general property of snow or general spectral reflectance curve for snow. Among this the coarse grained or coarse grained means larger grained snow will have still lower reflectance than snow which is composed of fine grains. And hence the grain size how small the grain sizes will increase the reflectance. So finer the grain size higher will be the reflectance, coarser the grain size or larger the grain size lower will be the reflectance. So this will be in general applicable across all bandwidths and this effect will be more pronounced in the NIR and SWIR ranges. Say we will again go back to the curve here if you look at or compare both the curves the difference between both the curves is very minimal in the visible domain. Both the curves are almost close to each other and still we have very high reflectance not much of a difference. Once we enter or once we cross this 0.8 micrometer when we enter the NIR portion of electromagnetic spectrum the differences begin to increase the difference between fine grained snow and coarse grained snow. And as we progress or as we increase along the wavelength we are we can observe larger difference in reflectance between fine grained snow and coarse grained snow. This difference is again highly amplified in the SWIR domain. Say here we can observe the peak here is much higher when compared with peak here. Here also this is one thing and also we can note a characteristic dips closer to the water absorption bands even in case of snow 1.4 and 1.9 micrometers characteristic dips may most likely will be present. So in general in order to understand the spectral reference property of snow snow has very high reflectance in the visible bandwidth and the reflectance begins to decrease starting from NIR and in general the reflectance decreases as wavelength increases. Then for fine grained snow or snow packed with smaller grain size the reflectance will be higher than the snow with larger grain size and this difference in grain size is highly amplified in the infrared domain especially NIR and SWIR domain of electromagnetic spectrum. So this particular slide further emphasizes how grain size influences the spectral reflectance of snow. So the figure given in the left side spectral reference of snow with snow having grain size with varying radius is being plotted. So the radius starts from 50 micrometers and goes all the way up to 1000 micrometers. We can observe as the grain size increases the reflectance keeps on decreasing continuously. The difference is not much in the visible domain but it is much higher in the NIR and SWIR domain. Maybe this will give the figure on the right side and will give a more clear picture like here we can see how the reflectance varies as a function of square root of grain radius. So in the x-axis we have square root of grain radius in the y-axis we have the reflectance. We can see invisible domain or even up to say 0.8 micrometers or the change in slope of this curve is fairly shallow. So which signifies that reflectance does not vary much with increasing grain size up to 0.8 micrometers. Once we cross this 0.8 micrometer domain then the reflectance begins to increase quite fast as the grain size increases and it is like highly amplified as the wavelength increases. We can just compare the, we can compare how the reflectance changes, how fast it decreases for wavelength starting from 1.1 micrometer up to 1.8. Even in 1.8 it is almost like kind of low exponential kind of decrease. It starts pretty high reflectance then suddenly it falls to very low reflectance. This signifies that grain size plays a major role in controlling the reflectance of snow and this difference is highly amplified in the infrared domain of electromagnetic spectrum. The next feature that we are going to see is the snow age. We have already seen that as the snow ages or as the snow becomes older the grain size tends to increase more and more snow may fall on it it may become densely packed or the grain size may increase and when the grain size increase we know the reflectance will decrease. So in general as the snow ages the reflectance decreases primarily because of increase in grain size. An example is given here in this particular slide. So this is the spectral reference of fresh snow with the density of about like 0.2 grams per cubic centimeters. Here it is a 20 day old snow this dark black line with a higher density. So as the snow becomes older it will get more dense and its grain size will increase leading to a decrease in spectral reflectance observed. Then snow may undergo process of melting and refreezing or water may get added to the snow pack. So presence of water in the snow pack will make the snow to form larger clusters that is let us say some small water droplet is present there. So snow particles may tend to form cluster around it and in general became like one large mass or one large cluster. This kind of occurrence or this kind of practice may increase the overall grain size of the cluster like in order to cover the single water drop many number of smaller grain crystals snow grain crystals may surround it and became one larger cluster which will affect the spectral reflectance. So primarily if the snow grain size changes or if snow forms cluster because of presence of water molecules within it then its reflectance will go down because it is more related with the change in grain size rather than presence of change in water. In the visible NIR presence of mere water may not change the reflectance much but if the snow becomes cluster due to the presence of water and becomes one large mass then it may affect the reflectance of snow and also once snow melts and then refreezes the reflectance may not be as high as the first initial phase that is given here in the slide. See here the spectral reflectance curve A indicates the reflectance curve for original cold snow with some density value then when the snow melts the reflectance curve falls to curve B which is like a dotted black line represented here. So the reflectance decreases as the snow melts then the same snow refreezes but the refrozen snow the reflectance will not increase as much as the original condition. So this will increase from the melted state but still the density the density has increased and hence the reflectance will be lower than the original reflectance that was first observed in the snow was completely in a frozen state. So presence of water also will try to bring down the reflectance of snow particles. The next property we are going to observe is the solar zenith angle. So solar zenith angle basically signifies in which angle solar radiation comes and falls on the snow pack. So in general as the solar zenith angle increases the reflectance will increase that is if the snow surface is like this let us assume the sun is directly shining from overhead that is sun is at the zenith angle is 0. That is the case we will we can measure one sort of reflectance curve then as the sun's zenith angle increases then the solar or sorry the snow pack reflectance will increase. So an example is given in this particular slide. So here you can see the reflectance curve is plotted for one particular snow grain size with varying solar zenith angles. So we can observe in general the reflectance increases as the solar zenith angle increases. So this is for one particular snow size without changing it and everything is measured with direct solar radiation. So diffuse by direct ratio is 0 that is whatever is the energy measured or plotted in this particular curve everything is primarily due to the direct radiation from the sun and the diffuse radiation is completely controlled for building this curve and diffuse radiation is 0. So that is why the diffuse to direct ratio is given as 0. This is because objects may behave differently under the influence of diffuse radiation. So in order to understand the effect of direct solar radiation controlled lab experiments were carried out where the diffuse radiation was completely cut out and only direct solar radiation was allowed to fall. And finally presence of any contaminants. So I told you before that snow has the highest reflectance among most of the commonly occurring earth surface features especially in the visible domain. So whatever be other objects when it falls on snow it will reduce the reflectance of snow say some sort of dust, some sand particles, some vegetation, something whatever falls on snow will in general have lower reflectance than the original reflectance of snow. This is highly true in visible domain. So presence of any contaminant will decrease the overall reflectance of snow. A very good example is given in this particular slide. So here we can see like this is like a fresh snow taken during like just after like winter season after everything got like accumulated can see how bright it is. So the figure on the right side it is taken after certain time period in like spring and summer season where a large fraction of snow has melted and due to the spring and summer season lot more like particles got travel and got settled in top of the snow cover. And this changes the total reflectance of snow. So we all know that we might have heard in scientific articles and all like deposition of any dust particles over the snow will lower its reflectance which will alter the energy balance of the snow pack. It may faster or it may make the melting to occur more fast. So the presence of dust will not only change reflectance it also has a larger implications in maintaining the surface energy balance of snow. So this covers the spectral reflectance property of snow basically. But remember one thing whatever the spectral properties or whatever the different factors that control them we have discussed most of the curves have been obtained under strict lab conditions like as I told you in the just in the previous example above the solar zenith angle in order to study the property of snow only under the influence of direct sunlight diffuse skylight was made zero in by controlling other factors in the laboratory. It is possible only in control lab conditions but during field experiments or during field visits we may not see the patterns a very good example is soil like when I explained about the properties of soil I told you that fine grained soils like silt or clay has higher reflectance than coarse grained soils like sand this is under lab conditions but under field conditions this may be completely reverse fine grained soils like clay or silt may have lower reflectance because of various other factors involved. So on field and in laboratory the conditions may be extremely different and we should always apply our due diligence when we try to compare the spectral reference curve obtained during field measurements and with the spectral reference curve obtained under controlled laboratory conditions we should always consider what are all the differences or what are all the other factors that may play a role in changing the spectral reflectance curves obtained under field conditions. So, if we look different remote sensing images and if the image has both snow and cloud then there may be a confusion for us to identify which one is snow and which one is cloud we may be able to identify using some other features like snow may be occurring like a large pack or clouds may have like some specific patterns or it may cast shadow on the ground all those things may act as clues to us when we look at an image but how to differentiate cloud and snow spectrally we will see from this particular slide. So, in this slide the spectral reference curve of snow and cloud is actually being represented. So, here you can see in the visible domain or even up to like NIR bandwidth the reflectance of snow and cloud are more or less similar. So, it will always be impossible for us to spectrally differentiate cloud or snow up to NIR domain say up to say 1.4 micrometers or something. But once we cross the 1.5 micrometer domain or 1.4 micrometer domain then the reflectance of snow will decrease drastically but cloud will still have higher reflectance. So, the best possible band to observe cloud or to differentiate cloud and snow will be the SWIR band short wave infrared band greater than 1.5 micrometers. In wavelength less than this value or less than this threshold reflectance of snow and cloud will be more or less the same and we may not be able to differentiate them spectrally. We may have to do based on other features as I told based on like cloud shadows or something but spectrally differentiating cloud and snow may not be possible in wavelength less than 1.5 micrometers and after 1.5 micrometers they may become more clear and visible. So, with this we end the spectral properties of snow. The next topic we are going to enter is what is known as a spectral indices or more commonly known as vegetation indices. I prefer to use the term spectral indices because nowadays such indices are being developed unused not only for studying about vegetation but also for various other features on the earth's surface. So, in common we will use the term spectral indices but when we talk especially about vegetation then we may use the term vegetation indices. So, what exactly a spectral index is? So, spectral index is singular term and spectral indices is the plural term. So, what exactly a spectral index is? A spectral index is a combination of reflectance in more than one band of electromagnetic spectrum. Here band especially I am talking in wavelength less than 2.5 or 3 micrometers especially visible NAR and SWR domain. So, if we combine the reflectance of certain feature in more than one band such that the combination produces one single numerical value out of it like we may divide one over the other we may add something or we may multiply one with some other factor whatever. Essentially we are combining the spectral reflectance of a feature in more two or more than two different bands such that they produce one number one numerical value. And by looking at that particular numerical value we will be able to tell some information about the physical or other properties of that particular feature of interest. So, one of the earliest spectral indices that was developed is like a ratio index that to for vegetation say a small introduction I will give. Say in olden days when the when remote sensing was primarily used for understanding the or monitoring the vegetation people were having difficulties in comparing the spectral reflectance images acquired during different dates or during different places etc. Because as I told you the spectral reflectance curve we obtained from remote sensing images may not only be affected by the terrain but it may also be affected due to surface topography, solar illumination angle, atmosphere and various other factors. So, in order to remove them people were trying different concepts or different methodologies. Once a simple methodology that was developed using a ratio index. So, ratio index is just dividing the spectral reflectance or reflectance value in the red band or combining the spectral reflectance value in red band and NIR band that is rho NIR by rho red. So, this was one of the earlier developed spectral index we called it as the ratio index because it is a simple ratio dividing the spectral reflectance in NIR band by red band and the primary use of this is to monitor vegetation that was the major aim with which this index was developed. So, why what it will do if you look at this NIR is in the numerator red is in the denominator. So, when we we already know that for a healthy vegetation NIR reflectance will be quite high and red reflectance will be quite low and when vegetation undergoes stress red reflectance will increase that also we have seen like we have seen how red reflectance increase and how blue shift occurs that is how the red shift move towards the shorter wavelengths those things have already seen. So, for a healthy vegetation this ratio will be very large and for vegetation the stress or some sort of diseased vegetation this ratio will be smaller. So, just by looking at the value people were able to get some information about the vigor of vegetation vigor means the healthiness of vegetation and also after doing the ratio people are also able to remove some effect of topography, solar illumination etc. These two are like cortically placed bands next to each other. So, the effects may be more or less equal. So, people when they took the ratio of these two spectral reflectance values they were able to observe the features more clearly or they were able to reduce the effect of topography, solar illumination and various factors. So, the primary aim of developing such ratios or such spectral indices were to first thing to increase the information content about any one biophysical property of the feature under discussion. That is here in the example vegetation how healthy a vegetation is. So, just by looking at this number this ratio value we will be able to tell higher the number more healthier the vegetation is that sort of simple analogy we will be able to reach it and also it will reduce some other unwanted effects due to topography, solar illumination, atmosphere and so on. So, spectral indices helps us to remove some unwanted effects and also brings to the front more clearly some important biophysical characters about the feature of our interest. So, this was like one of the earliest spectral index that was developed. But the problem here is in the especially the ratio index is the values are unbounded unbounded in a sense let us say due to some reason the reflectance in red goes very close to 0. Then the ratio becomes extremely high it is it will approach towards infinity and also let us say some other reasons may or even the any difference in kind of like calibration may take the values to negative values sometimes it will happen like even if you process some satellite data you will understand due to the varying calibration constants used some reflectance value may go to negative region it is like mathematically it will happen not physically. So, under certain circumstances the ratio or the number may behave very widely it is unbounded as red reflectance decreases the value may increase suddenly all these problems will occur. So, from this particular simple ratio index people started developing other indices so that simple biophysical factor can be studied more in detail or in a clear way and at the same time some other unwanted effects will be removed. So, in this particular lecture we have seen about the spectral reflectance property of snow what factors will influence the spectral reflectance properties and also we have started discussing about what is known as a spectral index. So, in the next lecture we will see or we will get introduced to some of the few commonly used spectral indices and the major applications for which they are employed. With this in this lecture thank you very much.


In this video, we're gonna discuss the solution for question 10 on the practice midterm exam for calculus two math 12-20. And we're asked to compute the anti-derivative of x e to the negative x dx. Now this one right here when I look at it, this one screams integration by parts, right? Where we're gonna set u equal to x and dv equal to e to the negative x dx. And so why does this one scream integration by parts? Well, let's first remember what integration part says, right? If you're integrating u dv, this week will u v minus the integral of v du. So we have to look for a function for which we want to take its derivative. And we wanna look for a function for which we wanna take its anti-derivative. Well, because of the e to the negative x, the anti-derivative and the derivative are really just basically the same thing. It'll be e to negative x. There's not really much of a difference there, but there is an advantage by taking the derivative x, it's gonna vanish, right? The derivative of u will just be dx there. It just disappears. And then like I said, the anti-derivative of e to negative x is negative e to negative x. And so if we apply that principle, our integral will look like we have to take v times u, which gives us negative x e to negative x. And then we have to subtract the integral of negative e to negative x dx. For which case we have a double negative, they cancel out. And now I just have to find the anti-derivative e to negative x and look at that, I've already done it. How wonderful. And so our final answer would then be negative x e to negative x. We're then gonna negative e to negative x. And perhaps the most important part here is remember the plus c, right? This is an indefinite integral. We're looking for the family of anti-derivatives. And so forgetting the c is as if we take the initial value that our c was zero, right? We don't want that. So for full credit, we do need the plus c. You don't wanna forfeit that point there. But otherwise we get this very nice integration by parts. You're gonna wanna make sure you don't integration by parts for this exam.