I learnt that the permeability of an ion across the membrane contributes to the membrane potential as much as(or even more than) its concentration and electrical gradients. And so far I've made peace with the fact that Sodium, having a very low permeability, doesn't contribute much (through its own movement) to membrane potential despite having a high electrochemical gradient directed towards the cell's interior. Now, the confusing thing is that, if I imagine dumping some sodium ions (with their positive charge) on the cell's exterior, this would affect the electrical gradient of potassium (and in fact other ions)--because more positivity is recorded externally-- making potassium in particular less &quot;ready&quot; to diffuse out of the cell. The result of which would be a depression (that is a more negative value ) of the resting membrane potential. If potassium's extracellular concentration were increased instead, a similar effect would be observed. What exactly is wrong with this reasoning? I'm putting this forward because my Professor mentioned only extracellular potassium ion as having an effect on membrane's resting potential.
Why do we say there is an overall negative charge on the intracellular side of the plasma membrane at rest, and an overall positive charge on the extracellular side when both potassium and sodium are positively charged ions, and they are in relatively equal amounts on either side? It seems to me that both sides should be positively charged, and I can't get my head around it.
Backup of clients' directory to Windows Server 2008 We have a machine running Windows Server 2008, and we need to take backup of folder from a desktop on LAN. This folder is not shared.   Is there any tool or software to do this, or can a scheduled task be made which should automatically take the backup of that folder date-wise &amp; make a copy on server? Ie can we do it through Schedule Tasks option ?  Desktop systems have Windows Vista/Windows 7. Why would a company like Apple be buying back its own shares? What is the reason that a company like AAPL is buying back its own shares? Does it have too much cash and it doesn't know what to do with it? So it is returning the cash back to investors? How to prove sum of powers property of roots of unity? We know that $1+\alpha_1+\alpha_2+...+\alpha_{n-1}=0$ where $\alpha_i$ are the roots of $z^n=1$. How can I prove that: $$1+\sum_{i=1}^{n-1}\alpha_i^m=\begin{cases}0\quad m\in Z,m\not\equiv0\pmod n\\n\quad m\in Z,m\equiv0\pmod n\\\end{cases}$$ How to input integer value to an array, based preceeding row + column values? AJAX: Check if a string is JSON? I’ve recently purchased a new Mac Mini, and I’ve been importing my old pictures into the Photos app.  I want to have these photos backed up to iCloud, along with the photos currently on my iPad. I then want everything synced to my Mac Mini, but not to my iPad, which has limited storage capacity.  Is it possible to have the Mac Mini and iPad set up to backup to iCloud, but only download backed-up photos to the desktop? When should "into" be used rather than "in to," and vice versa? "Into" (one word) and "in to" (two words) are frequently confused.  In what situations should the former be used?  The latter? How to automatically generate N "distinct" colors? Suddenly Okular will not open any more I have made my laptop double boot a few months again, with Ubuntu 18.04.1 . I have been working with okular to open pdf files (for the commenting option) but suddenly okular doesn't work anymore. When trying to open okular I get the following error:     Unable to find the Okular component: Cannot load library /snap/okular/39/usr/lib/x86_64-linux-gnu/qt5/plugins/okularpart.so: (libKF5JSApi.so.5: cannot open shared object file: No such file or directory)   I don't understand how to solve this problem. Okular was working fine until today and I didn't change anything to my ubuntu system in the mean time. Perhaps the problem comes from the fact that I have been working on windows the last few days and also used the windows ubuntu app.   How can I make okular work again? Is static HTML the fastest? I have been researching several different techniques to deliver web content fast, like nginx and node.js.  When it comes down to performance optimization http expires headers and gzip come to mind. After that come common techniques like sprites and CDNs etc.  But I am wondering.  What would be the very fastest technique to load a website?  Is static html the very fastest that can be? Or is there something else even faster? PDF editing within Apex/Visualforce Is there any measurable time dilation when Earth reaches perihelion? Can we measure such a phenomena relative to the motion of the outer planets? What software programs are used to draw physics diagrams, and what are their relative merits? Undoubtedly, people use a variety of programs to draw diagrams for physics, but I am not familiar with many of them.  I usually hand-draw things in  which is powerful in some regards, but it is time consuming to do things like draw circles or arrows because I make them from more primitive tools.  It is also difficult to be precise.    I know some people use LaTeX, but I am not quite sure how versatile or easy it is.  The only other tools I know are Microsoft Paint and the tools built into Microsoft Office.  So, which tools are commonly used by physicists?  What are their good and bad points (features, ease of use, portability, etc.)?  I am looking for a tool with high flexibility and minimal learning curve/development time.  While I would like to hand-draw and drag-and-drop pre-made shapes, I also want to specify the exact locations of curves and shapes with equations when I need better precision. Moreover, minimal programming functionality would be nice additional feature (i.e. the ability to run through a loop that draws a series of lines with a varying parameter).  Please recommend few pieces of softwares if they are good for different situations. What is the most practical way to implement camera/viewport to a 2D-game?  I've read, that I should store the object world position instead of position relative to the screen?  Current situation:  I have implemented a simple 2D-game where I load objects and levels from XML-files. Currently the level XML-file looks like this:  &lt;map&gt;    &lt;tile obj="ground" x="0" y="555" /&gt;    &lt;tile obj="ground" x="16" y="555" /&gt;    &lt;tile obj="ground" x="32" y="555" /&gt;    ... &lt;/map&gt;   All objects have a 2d-vector "position" storing their current location on the screen.  What I want it to be:    In the picture:   Camera is either 800x600 or 640x480 Blocks and sprites are 16x16 pixels. World size may vary The coordinates probably should be normalized relative to the world, not to the screen? Viewport position relative to player's x, y and moves when the player reaches camera dead zone (similar to ).   I'm asking pseudo examples / articles, but if you need to know what I'm using for the development: SDL &amp; C/C++. Prove $\mathbb{Z}_2 \times \mathbb{Z}_2$ is not isomorphic to $\mathbb{Z}_4$ Let $X$ de a vector space and $A\subset X$. If we define $A+B :=\{a+b|a\in A, b\in B\}$ I am trying to show that    $$ \begin{equation} 2A \subsetneq A+A, \end{equation} $$  i.e., it might happen that $2A \neq A+A$. I was able to show that $2A \subset A+A$, but I am not able to come up with a counterexample to show that the converse is not necessarily true. If I assume $A+A\subset 2A$ and let $x\in(A+A)$, then by its definition we have $x=a_1 + a_2$ for some $a_1,a_2\in A$ I guess I could naively say that $a_1+a_2 = 2(a'_1+a'_2)$ where $a_i=a_i/2$ for $i=1,2$ and I guess $(a'_1+a'_2)$ might not be an element of $A$ in some concrete case but I am not able to come up with anything and I've spent more time than I would like to admit. Any suggestions?  Thank you. What exactly are the spikes, or peaks and valleys, caused by in pictures such as these    Wikipedia states that "From the point of view of magnetic energy, peaks and valleys are energetically favorable", but I'm not exactly sure what that means, or how it works. Why isn't the fluid just happy being attracted to the magnet in a semi-sphere shape? Could it be that it gains a magnetic charge, so it attempts to repel itself at the same time? Just pulling at straws here. event.returnValue is deprecated. Please use the standard event.preventDefault() instead I've not seen/read any female Orcs mentioned in the movies or in the books. In one of the movies, an Uruk-hai is momentarily shown emerging from a giant, grown-Orc sized flesh packet. So are they created with spells, or do they follow the Standard Reproductive Model. virtual methods