I have a site made by wordpress. This site has some google rankings on 1st page in some keywords. Some pages appeared on 1st page of google search. However, since about 2 months ago, some ranking drops have been beginning as below.  Also, appeared keywords in google search console were reduced. Is this happening as a result of google penalty? I had no black seo to this site.
There has been a significant drop (90%) in traffic from Google to one of my well-established sites (6+ years) in the last week. Searches show that the top 3 wide keywords all dropped 4 spots. Searches for other keywords do not show ANY results in the first 10 to 25 pages of results, while previously one 1st or 2nd page at most.  Since there are , the question really is:  What steps are necessary to figure out what caused such a drop?  There have been no major changes during this period or the last month on the site and certainly not in the homepage which has dropped in rank. Over all the years of running this site and plenty of others, I have never experienced this. There are is duplicate content on my site and I have rigorously used canonical links for the last few years to ensure it is not misinterpreted as such.
How to center an element horizontally and vertically 24% tax on first pay in the UK? Quite a similar thread to others I've seen here - hope I'm not repeating the same questions again!   I just got my first payslip after arriving in the UK and noticed that the tax is far higher than the HMRC rate for my salary bracket.     I did some research but couldn't find any reason why I would be taxed at 24.23% of my gross this month AND then an additional amount for NI.    I have about £640 back pay from April that is only being paid now,but even so, it doesn't explain the rather large discrepancy between the HMRC rate and what I'm seeing here.   Any ideas? Why "a user" instead of "an user"? I am getting confused while using an article an. Because an is used while referring to vowels (a,e,i,o,u).  But today I read an article where for user they used a user.  My question is, why was an not used?  Could someone explain this with an example? This is a follow-up to this question:   Hans Bethe wrote a paper in 1944, "Theory of Diffraction by Small Holes," Phys. Rev. 66, 163. I don't have access to the paper, but from descriptions online it sounds like he proved the following. Suppose a plane wave impinges on an absorbing sheet, and there is a hole in the sheet of diameter $d$, with $d&lt;\lambda$. Let $P_0$ be the power incident on the hole, and $P$ the power diffracted through the hole. Then the transmission is $T=P/P_0=(d/\lambda)^4$.  As a practical application, I think this explains why microwaves don't leak strongly through the metal grille in the front of a microwave oven.  Questions:   Does the thickness of the sheet matter? From references online, it sounds like the hole is treated as a waveguide...? This seems to relate to cutoff frequencies of waveguides, etc.? It seems to me that Huygens' principle would give $T=1$ for $d\ll\lambda$, since in this limit the wavelets are in phase. Why is Huygens' principle invalid here? Is this related to question #1? Is there a simple argument for the proportionality to $(d/\lambda)^4$? Or if not, how does one prove this using the gory details of Bessel functions, etc.? I'm working on a 2nd order passive low pass filter, consisting of two passive low pass filters chained together.         &ndash; Schematic created using   Let \$ H(s) = H_1(s)H_2(s) \$ where \$ H_1(s) \$ and \$ H_2(s) \$ are the transfer functions for each separate filter stage.  Then \$ |H(s)| = |H_1(s)||H_2(s)| \$  Knowing the magnitude of a passive low pass filter,   $$|H(s)| = \dfrac1{\sqrt{ (\omega R_1C_1)^2 + 1} } \times \dfrac1{\sqrt{ (\omega R_2C_2)^2 + 1} } = \dfrac1{\sqrt{((\omega R_1C_1)^2 + 1)((\omega R_2C_2)^2 + 1)}} $$  Then trying to find the cutoff frequency:  $$ \left(\dfrac1{\sqrt{2}}\right)^2  = \dfrac1{\sqrt{((\omega R_1C_1)^2 + 1)((\omega R_2C_2)^2 + 1)}} $$ $$ 2  = \sqrt{((\omega R_1C_1)^2 + 1)((\omega R_2C_2)^2 + 1)} $$ $$ 4  = ((\omega R_1C_1)^2 + 1)((\omega R_2C_2)^2 + 1) $$ $$ 4  = (\omega R_1C_1)^2(\omega R_2C_2)^2 + (\omega R_1C_1)^2 + (\omega R_2C_2)^2 + 1 $$  And I'm stuck. Research on the web tells me \$ \omega_c = \dfrac1{\sqrt{R_1C_1R_2C_2}} \$, but I can't find why? Can anybody show my the derivation to find this? Using select by attributes then calculate field on selection in ArcPy? ArcGIS Pro 2.3  I want to create a standalone script which runs outside of ArcGIS Pro (for automation purposes), which selects features (with blank attributes) in a feature class and runs calculate field on those selections.  The code below doesn't work. It updates all fields, not the selected ones.  import arcpy arcpy.management.SelectLayerByAttribute(r"C:\Automation\Categories\Coal\Coal_automation.gdb\CLAIMS", "NEW_SELECTION", "Claim_Spend_in_£ = ''", None)  arcpy.management.CalculateField(r"C:\Automation\Categories\Coal\Coal_automation.gdb\CLAIMS", "Claim_Spend_in_£", '"Unrecorded"', "PYTHON3", None) print ("Done")   How can I write the code to run calculate field on a selection? I have the following enumeration:  public enum AuthenticationMethod {     FORMS = 1,     WINDOWSAUTHENTICATION = 2,     SINGLESIGNON = 3 }   The problem however is that I need the word "FORMS" when I ask for AuthenticationMethod.FORMS and not the id 1.  I have found the following solution for this problem ():  First I need to create a custom attribute called "StringValue":  public class StringValue : System.Attribute {     private readonly string _value;      public StringValue(string value)     {         _value = value;     }      public string Value     {         get { return _value; }     }  }   Then I can add this attribute to my enumerator:  public enum AuthenticationMethod {     [StringValue("FORMS")]     FORMS = 1,     [StringValue("WINDOWS")]     WINDOWSAUTHENTICATION = 2,     [StringValue("SSO")]     SINGLESIGNON = 3 }   And of course I need something to retrieve that StringValue:  public static class StringEnum {     public static string GetStringValue(Enum value)     {         string output = null;         Type type = value.GetType();          //Check first in our cached results...          //Look for our 'StringValueAttribute'           //in the field's custom attributes          FieldInfo fi = type.GetField(value.ToString());         StringValue[] attrs =            fi.GetCustomAttributes(typeof(StringValue),                                    false) as StringValue[];         if (attrs.Length &gt; 0)         {             output = attrs[0].Value;         }          return output;     } }   Good now I've got the tools to get a string value for an enumerator. I can then use it like this:  string valueOfAuthenticationMethod = StringEnum.GetStringValue(AuthenticationMethod.FORMS);   Okay now all of these work like a charm but I find it a whole lot of work. I was wondering if there is a better solution for this.  I also tried something with a dictionary and static properties but that wasn't better either. Is "coachee" even a word? If I am Rita's coach, is Rita my *coachee? (yikes) Is that even a word? Would it be correct instead to say she is my ward? What about terms for people at the other end of a mentor, sponsor relationship? How to use EntityFieldQuery with dates? I need to select entities with specific dates.   How should the following be formatted. Do I need to parse 15-May-2010  Also how I get the error page.   function events2() {  $query = new EntityFieldQuery(); $query   -&gt;entityCondition('entity_type', 'node', '=')   -&gt;propertyCondition('status', 1, '=')   -&gt;propertyCondition('type', 'event')     -&gt;propertyCondition('field_event_date', '15-May-2010', '=');  $result = $query-&gt;execute();   return $result;  } Could the Horcruxes be destroyed with Avada Kedavra? In The Deathly Hallows Hermione says this about destroying Horcruxes:     “It doesn’t have to be a basilisk fang,” said Hermione patiently.   “It has to be something so destructive that the Horcrux can’t repair   itself. Basilisk venom only has one antidote, and it’s incredibly   rare—"      "That’s a problem we’re going to have to solve though, because ripping, smashing, or  crushing a Horcrux won’t do the trick. You’ve got to put it beyond magical repair.”   Mad-Eye Moody from The Goblet of Fire tells us this about Avada Kedavra,     ...there's no countercurse. There's no blocking it.   but also that,      Avada Kedavra's a curse that needs a powerful bit of magic behind it - you could   all get your wands out now and point them at me and say the words, and I doubt   I'd get so much as a nosebleed.    Harry is also seen once attempting to use Crucio on Bellatrix Lestrange in The Order of the Phoenix out of anger at the death of Sirius, but he fails. She tells him,     "You need to mean [Unforgivable Curses], Potter! You need to really want to cause pain - to enjoy it - righteous anger won't hurt me for long - I'll show you how it is done, shall I? I'll give you a lesson -"   Even if Harry and company are not powerful enough to perform the curse themselves, they know several powerful wizards (Kingsley, Lupin, et al.) who could likely perform the curse.  Lastly we know that Voldemort himself destroyed the last bit of his soul that was inside Harry with Avada Kedavra.  Could the Horcruxes be destroyed with Avada Kedavra as well? When were the 'and' and 'or' alternative tokens introduced in C++? I've just read this  from Reddit.  They mention and and or being "Alternative Tokens" to &amp;&amp; and ||  I was really unaware of these until now. Of course, everybody knows about the , but and and or? Since when? Is this a recent addition to the standard?  I've just checked it with Visual C++ 2008 and it doesn't seem to recognize these as anything other than a syntax error. What's going on? Uniform random variable as sum of two random variables Taken from :  Show that it cannot be the case that $U=X+Y$ where $U$ is uniformly distributed on [0,1] and $X$ and $Y$ are independent and identically distributed. You should not assume that X and Y are continuous variables.  A simple proof by contradiction suffices for the case where $X$, $Y$ are assumed discrete by arguing that it always possible to find a $u$ and $u'$ such that $P(U\leq u+u') \geq P(U\leq u)$ while $P(X+Y \leq u) = P(X+Y \leq u+u')$.  However this proof does not extend to $X,Y$ being absolutely continuous or singular continuous. Hints/Comments/Critique? I've recently searched how I could get the application's directory in Java. I've finally found the answer but I've needed surprisingly long because searching for such a generic term isn't easy. I think it would be a good idea to compile a list of how to achieve this in multiple languages.  Feel free to up/downvote if you (don't) like the idea and please contribute if you like it.  Clarification:  There's a fine distinction between the directory that contains the executable file and the current working directory (given by pwd under Unix). I was originally interested in the former but feel free to post methods for determining the latter as well (clarifying which one you mean). Fix terminal after displaying a binary file The union of a strictly increasing sequence of $\sigma$-algebras is not a $\sigma$-algebra Let's stop displaying a user's accept rate Cannot Select Linked When Sync Selection Is Enabled My final goal is to generate Impulse Response Functions in R.  I have variables that are non stationary when I set k = 5 in a Unit Root test, and they are cointegrated which to my understanding prompts the use of the VECM, from which the Vec2Var argument is used to then generate IRFs. However, my response functions from this methodology do not decay over time and mostly do not revert to the zero line.  Furthermore, I noticed that when I input first differenced variables into the VECM as opposed to level data above, response function do revert to the zero line. Therefore my first question is: 1) is it appropriate to use differenced variables in a VECM model?  Secondly, as an alternative I am considering restricting the number of lags used in the Unit Root tests so that the variables are not all non-stationary; in this case 2) would the use of VECM be void and the VAR with first differences be a more appropriate model? Again, using differenced data is giving me better response functions that revert to zero in the long run. However, 3) is it ok to use the VAR for stationary/non-stationary data in levels where these variables are still cointegrated?  Also, I am using growth rate variables, 4) should I still long transform all variables and use logs in all tests?  Thank you for the help! If $G$ has no proper subgroup, then $G$ is cyclic of prime order This is something I'm supposed to be able to prove for an upcoming test, but I can't find anything to help me prove this in my notes or the chapter, which is on cosets and Lagrange's theorem. If all I start with is the group having no proper subsets, then that means any subset is the whole group. By Lagrange's theorem, that means the index is $1$, but that doesn't get me anywhere. Where do I start? Centos mysql version is 5.5 however PHPmyadmin still says version 5.1 When i run the following in my console:  [root@****~]# mysql -u root -p -e 'SELECT VERSION();' Enter password: +-----------+ | VERSION() | +-----------+ | 5.5.39    | +-----------+   Which should be the correct version.  However when i enter my PHPMYADMIN on my server it has the following specs:  Server: Localhost via UNIX socket Program: MySQL Programversion: 5.1.73 - Source distribution   So which version is the correct one and how do i make sure that the database is running on 5.5?  Note  I have already restarted sql several times without any changes