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User talk:MichaelBillington

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User talk:Giawa

Interested in C++, C#, Java, OpenGL, GLUT, Tao Framework, OpenAL, AI, 3D Optimizations, 3D (Collisions, Physics, Animation, Implementation), Electronics, Integrated Circuits, Digital to Analog and Analog to Digital Conversion... okay... The list goes on, and I can't learn it all :(

I'm enrolled at the University of British Columbia in the Electrical Engineering program. I try to come back to wikiversity every so often to write new articles on the stuff that I love (computers!), but finding the time these days is tough. Good luck with whatever you chose to pursue, and once you've learned what you want to know you should come back to wikiversity and post it!

title: User talk:Giawa


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Wikiversity talk:Main Page/Archive 2

Main Page | talk | archive

 * Please archive conversations from August at Wikiversity talk:Main Page/Archive 1
 * Please do not edit these archived sections

New page design
Trevor has done extensive work to create a very nice design for the main page, moved to new page: Main_Page/Design (old page User:Trevor MacInnis/MainPage). It could still be tweaked but it is better than what we have. (See original discussions above in "new page format") Shall we take a quick head count on using the new design -- 24 to 48 hours? Enough time for sense of no objections? Reswik 18:14, 23 August 2006 (UTC)

Original version
Do you support or oppose using this design on the front page: Main Page/Design (new location)?
 * -- tweaking needed; can go up; design 2 has more code cleanup done so prefer that Reswik 18:14, 23 August 2006 (UTC)
 * - Sure. Looks great, why not? This is a new place, should be able to experiment with a few things. --HappyCamper 20:08, 23 August 2006 (UTC)
 * I would prefer larger fonts across the board. Scrolling is better than squinting. However, it does provide a crisp image of professional design and will no doubt continue to evolve.  Mirwin 04:20, 24 August 2006 (UTC)
 * I like it; very unique, but also clean and functional. There are some minor usability issues, but I'm sure they could easily be resolved. --Aepex 06:17, 24 August 2006 (UTC)
 * . I support Trevor's efforts, but this design isn't ready for implementation.  (Please see User talk:Trevor MacInnis/MainPage for some of my objections.)  It has the potential to evolve into something better, but it would be a mistake to rush it onto the main page before it's ready.  (I'm not saying that it can't be tweaked after it goes live, but it should be further along than this.)  —David Levy 07:29, 24 August 2006 (UTC)
 * It's definitely better than the current Main Page, but I think it could do with some tweaking. I don't like that overlapping globe thing, for a start – Gurch 12:31, 24 August 2006 (UTC)
 * - Great work! Think marketing guys, a great design like his can enhance user experience thus attracting more users and make people more willing to contribute. Rayshan 14:14, 24 August 2006 (UTC)
 * Like Gurch, I don't like the overlapping globe, nor the overlapping boxes. I feel like there are too many boxes, and this moves away from my vision of Wikiversity, which in my minds aims at being user-friendly and intuitive. Well done for your work however. guillom 14:36, 24 August 2006 (UTC)
 * - Wikiversity is still too small to have something like the wikipedia main page redesign.  If you don't like it, work up your own design.  I think we all can agree this is better the the present one.--Rayc 02:05, 25 August 2006 (UTC)
 * No, not all of us agree that it's better. The issue of aesthetics is subjective (and I'm clearly outnumbered on that front), but the time/date stamp feature is sometimes broken (due to caching), and I guarantee that the text is more difficult for people with visual impairments to read.  (This is an area in which I have some degree of expertise.)  Accessibility is of the utmost importance, and I'd like to think that it would be considered before any new design is rushed into use (even if it looks good to most people).  The current design isn't flashy, but it's quite functional.  Can we please not take a step back in this regard?  The problems that I've cited can be addressed (and I truly see a great deal of potential for a nice design that sacrifices no usability), if only we can be slightly patient.  —David Levy 03:52, 25 August 2006 (UTC)
 * I agree that usability is important. I think a few days of review is a good thing for a really new design, even in a good project. Trevor has tweaked the design. See below. Reswik 13:13, 25 August 2006 (UTC)

 * - I know I just joined, but I must say that from seeing the link to the design from the home page, I must say that it is quite nice for this site. It would really look well as it would show our own Wikiversity creativity, and not just use the standard setup.--Hd.G 06:04, 25 August 2006 (UTC)
 * - better than current one. --Steven Fruitsmaak (Talk) 16:18, 25 August 2006 (UTC)
 * Awesome job! I love the colors and the concept! -Yorktown1776 16:32, 16 September 2006 (UTC)

Modified version
Please post opinions regarding Main Page/Design 2. Do you support or oppose its adoption, and how does it compare to the original version?

 * Note: I'm aware of a minor display bug in Internet Explorer 6. (The image is off-center and lacks a right-hand border.)  Please assume that this issue (which does not exist in Firefox or Opera) will be corrected when the code is refined.  —David Levy 09:59, 26 August 2006 (UTC)

 * As they are now, I like Main Page/Design 2 slightly better than Main Page/Design- even though "Design 2" is quite plain, it 'gels' nicely - looks seemless. If I had a (very minor) tweak, it would be to centre the Browse box text under the "Welcome to Wikiversity" - as well as changing the motto/byline (but that's being worked on elsewhere). Good work everyone :-) Cormaggio 10:43, 26 August 2006

 * -- On a discussion string on his talk page, David points out that he cleaned up template formats and CSS code in working on Design 2. For this reason, I think we should post Design 2. Once the usability issues are addressed in Design 2, I think it can be posted. I prefer a few design aspects of both versions. We can polish and negotiate design features over time. A few design issues: I think it is important to include a sizeable graphic or photo (which could have a link to a blurb about how that item relates to wikiversity) near the top in whatever design evolves. I would like to see more white space in the main top title box. I prefer the mix of blue/tan in heading bars in Design 1. I like a "menu" line centered under the main title box but a top right box menu can work too. Reswik 17:27, 26 August 2006 (UTC)

 * - I'm sorry guys but I have to say that the 1st design is better and here's why: The use of icons helps to make the content graphically stand out. Graphics could generally be comprehended faster than words alone. (Although I don't think all the icons correctly represent the content, such as the broom). As far as color and layout goes, 1st design nicely group sub-content together in "boxes", but it may sometimes look a little "too much". 2nd design looks a lot cleaner, but I recommend something between main content and "Wiki in other languages" so everything don't blend together with the background. Also how about making "Wiki in other languages" and "Sister projects" centered? 66.177.92.226 17:36, 26 August 2006 (UTC)

 * thanks for points. I agree that some of design elements of Design 1 are more desirable (as I mention just above). But, we need to go with Design 2 code clean up or recreate that in Design 1. Perhaps it is easier to adjust graphic elements and reintroduce icons in design 2. Not sure. Reswik 17:49, 26 August 2006 (UTC)

 * In modifying the design, I drew upon the comments expressed here and those expressed by literally hundreds of users during the English Wikipedia's main page redesign process. Over there, the use of icons (including these exact images) was rejected by a clear majority of respondents (many of whom noted that they created an "unprofessional" or "childish" appearance).  As you noted, there is no strong connection between these images and the content that they accompany.  They serve purely as decoration, not as navigational aids.
 * The non-stylized Wikiversity in other languages and Wikiversity's sister projects sections (present in both versions) reflect an overwhelming consensus that emerged during the aforementioned English Wikipedia discussion. The idea is to visually differentiate between the dynamic and static content.
 * Indeed, one of my goals was to make the design cleaner and easier to read (which also entailed the use of larger text), and I believe that I've succeeded. —David Levy 18:08, 26 August 2006 (UTC)

 * I like Design2, but didn't notice a link to the tour. Would be nice if one were added, or made starker if it's there. Dev920 14:45, 27 August 2006 (UTC)
 * I've added the link. :)  —David Levy 15:17, 27 August 2006 (UTC)
 * Thankyou. :D Dev920 15:28, 27 August 2006 (UTC)

 * again, better than current one.--Steven Fruitsmaak (Talk) 19:01, 27 August 2006 (UTC)

 * looks better than both the current one and option 1, and is more organized than option one.--Hd.G 03:48, 28 August 2006 (UTC)

 * It looks good to me. Thanks for larger text. Mirwin 06:57, 28 August 2006 (UTC)
 * i agree that design version 2 is clearer and more to the point (although i do like the wikitrek blurb in design 1) --Smithgrrl 16:52, 28 August 2006 (UTC)

 * The overlap between the blue and orange where the "About • Browse..." links are is bothering the hell out of me, probably because I'm a web designer. I would support if that were changed.--  digital  _  me   16:56, 28 August 2006 (UTC)

 * Were you thinking that we would have two separate columns, one blue and one orange (tan)? Or, were you thinking something like what is now on Design 2 -- a blue bar across the top. Reswik 01:16, 29 August 2006 (UTC)

 * I oppose either change (and I've reverted).
 * As I noted on your talk page, the logic behind my configuration is that readers tend to notice solid elements of the same color that they're already looking at. If the left side of the page is predominantly blue and the right side is predominantly tan, they'll be more likely to concentrate on one and ignore the other.  By placing blue section headings below a tan header (and vice-versa), the users' eyes will naturally be drawn to both sides of the page.
 * One thing that became clear during the English Wikipedia's main page redesign process is that it usually isn't a good idea to rush to make major changes in response to a single criticism (especially when the status quo has generated generally positive comments). Nine times out of ten, you'll only end up upsetting more people than you please.  :)  —David Levy 01:39, 29 August 2006 (UTC)
 * The tan is drawing my eyes away from the main content, what we need is something to counterbalance it. Perhaps adding blue borders would help, but right now, the right side is too visually heavy.--  digital  _  me   02:34, 29 August 2006 (UTC)
 * Did you see what the page looked like with the all-blue header? The left side completely dominated.  Then, with blue on the left and tan on the right, it looked like two isolated entities (with the left side still dominating because it's much wider).
 * To me, the page looks fairly balanced now. If anything, the left side still stands out slightly more (because of the aforementioned width).  —David Levy 02:51, 29 August 2006 (UTC)
 * I think the current design looks better than the variations I explored last night. However, after trying to simplify the top, I think the approach of the new design in general has yielded looks that are too "busy" and distracting up top. If anyone wishes to play with the design, perhaps further work will resolve that. (I am not going to work on the design until after this passes). After this new design (which is certainly an improvement) is approved, I'm going to start working on further revisions on sandbox pages, perhaps variants of this design (or other another similar one), that have the masthead only across the top with two columns underneath. Reswik 14:19, 29 August 2006 (UTC)

 * I love the second page design. It looks wonderful and easy to organize new information into. It's inviting. OneWomanArmy --Diana 01:04, 5 September 2006 (UTC)

Comments

 * Summary of discussion (revised): This needs revisions for usability, then this can be posted. A strong majority would like to see this design posted (10 or 11 of 13, including 2 comments on Trevor's design talk page), and some say tweaking is needed first. Almost all would like to see the design tweaked somehow. In response to feedback, Trev has done extensive tweaking now, two rounds at least, including in response to above comments, to improve this. A few minor things remain to do. This is almost ready. ...
 * A longish discussion string from here moved to: Wikiversity talk:Main Page/Design.
 * See section above for Design 2 comments. Please share your comments about design 2 above.

Feel free to adjust the design:
 * Trevor moved the current version of the design to: Main_Page/Design.
 * Forked version of the design: Main_Page/Design 2
 * To do:
 * [Done] The right column text still needs work.
 * [Done--problem found--see comment below] Can someone check usability in JAWS or Window-Eyes.
 * Can someone check readability in the Safari browser at various screen resolutions?
 * Thanks, Reswik 20:52, 25 August 2006 (UTC)

 * I've been attempting to adjust the design, but the style templates are making this very difficult for me. If Trevor (or someone else) could move most of the code into the page itself, it would be much easier to edit.  I tried substituting some of the templates on a test page, but that broke much of the page.  —David Levy 21:19, 25 August 2006 (UTC)

 * [We figured out how to work with the templates.] Due to right column text size issues, I think the right hand Communication blurbs needs to be edited into shorter length at each bullet point. Reswik 21:31, 25 August 2006 (UTC)

 * Problems found via JAWS with new design -- these need to be addressed. See discussion on Wikiversity talk:Main Page/Design
 * Graphic/photo issue -- Should there be a photo or graphic in the top right area of the new design page? (The current top page photo is there and needs to be resized and/or centered if it stays.)

 * This is a comment that should be registered, but probably not acted on yet. The front page fails this accessibility checker - can we get a user familiar with accessibility issues to take a look at the new page and see if they can navigate through it? --HappyCamper 15:12, 26 August 2006 (UTC)

 * Contrast is disappearing: Design 1 and 2 are converging in appearance (due to Trevor adopting some of David's revisions). Design 2 code is partly revised for usability issues and being revised further. Reswik 15:58, 27 August 2006 (UTC)

 * Don't forget to include the new stuff that was recently included on the orginal main page. The drafts are starting to become out of date.--Rayc 04:57, 1 September 2006 (UTC)

Strafing
If i understand right, the goal of this project is to teach a man all the things (positive ofc) possible. Look, and if I have some Defrag strafing (computer sport game) skills? Is it forbidden here to teach people such things? Thank you.
 * I've no idea of what that game is, but I don't see a problem in uploading material that teaches people about how to play computer games - we haven't set policies yet on delineating our content (such as exists, for example, on Wikibooks). Just a side thought, but I think it would be really interesting to see what computer games can teach us about the world - if that could be developed, it could be a fantastic resource. Cormaggio 19:32, 24 August 2006 (UTC)
 * Oh, ok, thanks. I haven't played it for about a year, but i can ask world champion for it. Thanks!
 * Or, you oculd be a stunt coodinator for Wikiversity the Movie. Great gameplaying skills put to good use!--Rayc 01:54, 26 August 2006 (UTC)

And hopefully we can teach women too! I really get tired of the sexist language. It's so embedded in education as well as everything else. I can't be silent about it. It DOES matter. Already I feel excluded. No, the goal of this project is to share, collect and strive to educate human beings.User:OneWomanArmy--Diana 01:09, 5 September 2006 (UTC)
 * Absolutely. I feel terrible that you feel excluded. Of course it matters. I just didn't respond to this part of the sentence, because there were other things that the questioner (whoever he/she is) wanted to know about. But you're absolutely right to bring it up. Wikiversity is education for all. Cormaggio 14:57, 5 September 2006 (UTC)
 * I feel it important to note, in a pure and strict sense of education, that Latin is a root of English. The use of what appear to be masculine pronouns are also neuter pronouns based on context. Man, as in mankind, should not be misunderstood to mean only male humans, but the idea of all of humankind is expressed in that single word as best as possible. We shold also note that language begins verbally and becomes a written language after, logically but not necessarily chronologically as they can happen simultaneously. Some contexts provided druing speach may not be as easily communicated through written word. In any case, I don't think colloquial habits should be maligned, as over time any individual who increases in education naturally revises their use of language to an extent. To immediately highlight errors or discourteousness in the way in which a question is asked in lieu of adressing the content of question seems to me to be agaisnt the intent of Wikiversity. I also feel at this point that in order to not be misunderstood, I need to qualify that this is not not meant to be a personal attack of any kind nor truly a correction of previous behavior, but to highlight that a certain tolerance of each other will make the education process itself go more smoothly. And I hope we can all see that education will help each of us to refine ourselves from our current sate. Talonhawk 01:40, 13 September 2006 (UTC)

Favicon Suggestion
Your favicon is currenlty identical to wikipedia's... I keep links in my toolbar with only the icon, and I think having the hat would make more sense in any case. Just a random thought. 68.222.136.209 12:04, 2 September 2006 (UTC)
 * Yep, thanks, and fully agreed that we'll have to change that icon. We're currently in the process of changing our logo, though - details of which here. Maybe we should wait until that's decided? Cormaggio 16:28, 2 September 2006 (UTC)

Cooperation with Wikihowto
I would like to invite everyone to cooperate with Wikihowto. I think we nead a way to make Wikihowto an Wikimedia project. Andi think Wikiversity could, maybe not replace Wikihowto, but at least evolve hand in hand. I think the both Wikiversity and Wikihowto are made to evolve together, don't you think? Please think about it if you do and tell other people about this two projects. (moa3333) 80.236.113.58 12:01, 6 September 2006 (UTC) hm... there is one of these (insert link to Wikihow)--24.208.123.129 01:38, 7 September 2006 (UTC)

 * I made a link to Wikihowto at Educational Wikis. --JWSchmidt 02:05, 7 September 2006 (UTC)

I cant sign up!
It wont show me the security code, and i only see the dreaded little red x. :( --24.208.123.129 01:35, 7 September 2006 (UTC)Geobeedude
 * Account creation seems to be working now. --JWSchmidt 01:53, 7 September 2006 (UTC)

i still cant see the verification code.
 * There must be something wrong on your end, because other continue to be able to sign up, and I just checked and saw the codeword. I suggest trying to create an account from another computer, after that you'll be able to login from home as normal. - Trevor MacInnis 00:40, 11 September 2006 (UTC)
 * Signups are working fine. I suggest you try accessing Wikipedia through a free web based proxy, as these may alter the image as it is passed on. --Draicone (talk) 07:46, 13 September 2006 (UTC)

Vandal fighting unit
Similar to wikipedia:WP:CVU, I've established this page to co-ordinate vandal fighting efforts (although I doubt this is very important right now). I'm a developer for wikipedia:WP:MWT and I intend to alter it slightly to work with Wikiversity. Input would be appreciated. --Draicone (talk) 07:45, 13 September 2006 (UTC)
 * Please take a moment to read WV:SHRINE before you consider starting a vandal fighting project here. -- sebmol ? 16:06, 13 September 2006 (UTC)
 * I understand, and the goal of VFU is to identify vandalism, as once we reach a few thousands articles there will always be edits that go unnoticed. Any system established would include at least a couple of sysops and focus around recording vandalism attempts and reporting them to sysops (/custodians/admins/bureaucrats) so that appropriate action can be taken. --Draicone (talk) 12:39, 14 September 2006 (UTC)
 * I appreciate your enthusiasm but I also want to point out that vandalism and dealing with it is not supposed to be a big deal. People report it or notice it, it gets taken care of, we move on. By creating pages like the VFU, we're just creating yet another place for vandals to feel like they get any attention from us which presumably is exactly what we're trying to prevent. -- sebmol ? 18:23, 14 September 2006 (UTC)
 * I understand. However, I've clarified VFU and I really just want to establish a system in place and educate users on how to deal with vandalism - currently, there's no way of knowing what to do with vandalism besides revert it unless another user tells you what to do. There's nothing saying, "Contact a sysop at [ [here]  ]". Just reverting vandalism is good, but if vandals continue to compromise pages, people need to know what to do about it - in fact, they need to know what to do about it in the first place. I suppose a 'unit' is a bad idea, as it gives the impression of many vandal fighters actively reverting vandalism (which, unlike en:wp, is clearly not the situation). I simply felt that having a few users develop a page to educate the public on dealing with vandalism was useful. --Draicone (talk) 09:12, 15 September 2006 (UTC)

3/4th
We have spent 3/4th of wikiversity's existance redesigning the main page. Could we just throw one of the designs up there and call it good? It can always be reverted.--Rayc | (Talk) 04:28, 16 September 2006 (UTC)
 * We've got some content started, there's hundreds of pages listed at Special:Allpages. --Draicone (talk) 08:10, 16 September 2006 (UTC)
 * If we are talking about a "design change" then the new main page should have the same content as the current main page....just with a new design. I'm reluctant to switch to either Main Page/Design 1 or Main Page/Design 2 because they have content changes. It is not easy for me to follow the trail of of past discussions starting at Wikiversity talk:Main Page/Design 1 that might explain the content changes. There was a request made at  (Request custodian action) that "Design 2" be used, but there are no discussions at all at Wikiversity talk:Main Page/Design 2. If there are going to be content changes (new image, "where you can teach to learn and learn to teach", etc) then I would like to see a summary of the content changes and a description at Wikiversity talk:Main Page/Design 2 of how those changes were selected. --JWSchmidt 13:57, 16 September 2006 (UTC)
 * The bulk of the new design discussions are described here: Wikiversity_talk:Main_Page, with links in that discussion to points elsewhere. The discussion includes various summaries as does the admin request page. JW, since you have objected to the new design in the past (on the Design 1 talk page) and as you are responsible for many of the recent new content changes/tweaks on the old front page design since the new design was developed (and hence you can best summarize those), I do not think you should serve as facilitator on this issue. Just my opinion, Reswik 14:26, 16 September 2006 (UTC)
 * I have only had a few comments and suggestions about the new main page design. I originally wondered if what looked like an overlap in rectangles in the upper right corner was a an error. I was told that it is a design feature. I requested that there be efforts made to make it easy to read any blue text placed on a blue background. I think it is reasonable that any page content changes existing in the new design be summarized and justified all in one place. There is a difference between making changes to the main page (the most observed page of the wiki) and making changes on a page that ranked 92nd in terms of page views during the last week of August and 246th so far during September. --JWSchmidt 15:51, 16 September 2006 (UTC)
 * Another summary: Of expressed views about posting the new design, there is a strong majority in favor of posting the new design. Usability issues seem to have been addressed. I do not wish to summarize this further or put work into reconciling the old main page and new main page. If you want to revise Design 2 feel free. A further review of the details of summaries provided already in several places and how to deal new emergent issues due to edits to the old main page will be hopefully a task that a custodian or other volunteer who posts Design 2 will take on, whenever. Personally, I believe Design 2 is ready to post and be adjusted by the community. It is past time for that. Reswik 20:51, 16 September 2006 (UTC)
 * Yes, I'm just talking about the main page. Lot of other stuff has been done, improved, etc, but the main page, the most visable page, is pretty much the same as it was a month ago. Is there anything I can do to help out with the redesign? Have you considered the three click rule?--Rayc 18:26, 16 September 2006 (UTC)

 * I've implemented the main page as set out on Main Page Design 2. I've also refactored it a bit so individual parts can be edited by users without custodian privileges. Should this not work, the subpages can be protected as needed. -- sebmol ? 22:29, 16 September 2006 (UTC)

project page picture
why were Image:South African classroom.jpg chose. Is wiki international? I mean that it which explain all people should be choose.
 * It was changed from a bunch of dead white guys. It's an exact opposite picture and a stop gap until we get a random picture function or a logo to put their.--Rayc 18:28, 16 September 2006 (UTC)

Engineering PORTAL
the engineering link on the main page needs to go to Portal:Engineering and Technology, not School:Engineering
 * Changed it. Now the comSci people will have a 3 click path to there page from main.  --Rayc 18:43, 16 September 2006 (UTC)
 * That is ok, since before it was a 5 click path because you kept getting redirected to the wrong place. Damien Black 22:04, 16 September 2006 (UTC)

the engineering link was changed back to School:Engineering... why is it the only school there and why isn't it pointing to Portal:Engineering and Technology? Damien Black 23:27, 16 September 2006 (UTC)
 * Well, It might of been because of the main page switch over, though if not, there probably is a good reason for it. Math also has a school on the main page.--Rayc 03:26, 17 September 2006 (UTC)

Main Page picture
This new picture on the Main Page is certainly looking better than the previous one, and it associates on school and learning more efficiently, but its big problem is that there are no people in it at all. And since this aspect is very important, if I had to choose between them, I'd choose the old happy corridor instead of this sad abandoned lonely classroom. The old picture reflects the Wikiversity's openness and community way better than this looking-good, but wrong-message-sending one. --George D. Bozovic talk 23:22, 16 September 2006 (UTC)

 * Oh, I see, the pictures are changing daily. Good idea! --George D. Bozovic talk 01:08, 17 September 2006 (UTC)

An empty lecture hall isn't very wiki-ish, in my view, but I understand what "beta" means and will be back to see the steady improvements. Thanks for all the efforts. | Gardner Campbell 18:02 24 September 2006 (UTC)

Main Page: New Design
Nice design. Congratulations to the designers. 205.189.97.202 01:15, 21 September 2006 (UTC)

 * Yes, thank you very much to Trevor MacInnis and David Levy for their talented and extensive work in creating and refining the new main page design. Thank you also to everyone who shared input and comments. :) --Reswik 01:28, 21 September 2006 (UTC)

Motto for Wikipedia?
"Help create a motto and a slogan for Wikipedia." It should be Wikiversity, shouldn't it? –Dilaudid 21:47, 21 September 2006 (UTC)
 * Thanks for the hint, I've changed it. How embarrassing...-- sebmol ? 21:51, 21 September 2006 (UTC)
 * That makes me laugh. 205.189.97.202 02:18, 22 September 2006 (UTC)

Talk archive
Done talk needes to be deleted or archived to give focus to current talk. Archiving done talk for a month on a separate page provides users a place to check up on done talk they initiated, more graceful than deleting directly. If you can improve this, please do. Ideas? Thanks! :-) Rogerhc 04:27, 25 September 2006 (UTC)
 * I don't understand what you mean by this. Most of the time I just make a page like Wikiversity talk:Main Page/Archive 1 and place all of the non-current talk on there. You shouldn't ever completely delete anything.  --Mateo 18:05, 25 September 2006 (UTC)
 * I'll see if I can write a bot to auto archive the talk page, or better yet, find a bot that's already been written. --Draicone (talk) 23:15, 26 September 2006 (UTC)
 * w:User:Werdnabot might be useful, operated by w:User:Werdna – 86.138.33.165 22:39, 29 September 2006 (UTC)
 * If somebody is willing to give me approval and operate as a liason, then I can activate Werdnabot here. Werdna 09:09, 9 October 2006 (UTC)
 * Currrently I'm the only person authorised to give bot status on Wikiversity - the only unfortunate thing is that, when it comes to all things technical, I haven't a clue :-). But you could liaise with User:Sebmol (who, as far as I know, is working on a similar bot). Cormaggio 10:10, 9 October 2006 (UTC)

relation to wikipedia?
Does participation in this project require participation in wikipedia? I don't support wikipedia for a variety of reasons, but would like to edit here. What is the nature of the relationship between the two, beyond that they are owned by the same people. thanks. --Mateo 18:05, 25 September 2006 (UTC)
 * Well, a number of editors here, including myself also edit Wikipedia, so that's a definite connection. Also, many policies, and indeed articles are adapated from Wikipedia as the project gets started.  This project requires no participation in Wikipedia, so you shouldn't have to worry about that.--  digital  _  me   01:51, 26 September 2006 (UTC)

UC Berkeley offers courses and symposia through Google Video
UC Berkeley offers courses and symposia through Google Video. Should each Wikiversity course link to the relevant videos, if any are available? --DavidCary 05:57, 30 September 2006 (UTC)
 * I don't see why not. We encourage the use of learning materials, including those which cannot (due to technical or legal restrictions) be offered directly through Wikiversity. I'm not sure how many videos we'll actually have, however. --Draicone (talk) 09:22, 1 October 2006 (UTC)

General layout suggestions
I would like to suggest the following: I think Wikiversity should, as a general layout devide in accordence to the following hierarchy : ( the arrows are directed from high to low hierarchy.) general schools(e.g chemistry, psychology --> more specific schools(analytical chemistry or developmental psychology) --> courses --> lectures . Under that hierarchy I think each lesson/lecture page should have side pages (like "edit this page" and "discussion" ) in which a Q&A page from actual students and proffesors would be held. I'm only suggesting a discussion on "the general layout" and not making a pinpointed suggestion. If there is already a discussion on General layout somewhere then I'm truly sorry for I did not find it anywhere. in that case, please move my suggestions to the right place. --(User: Eshy, Israel - unregisterd Wikimediaist.)

 * A way of using "schools" was developed during the period of time that Wikiversity existed at Wikibooks (see b:Wikiversity:Wikiversity Schools). In that system, one school does not contain other schools. The curent system for a hierarchy of academic subjects is described at Namespaces and Naming conventions.

 * "each lesson/lecture page should have side pages (like "edit this page" and "discussion" ) in which a Q&A page from actual students and proffesors would be held" <-- I agree that Wikiversity needs to find good ways to promote discussions, question and answer sessions, debate, etc among participants. It is easy to make links to subpages that can hold discussions. Hopefully the wiki software will be improved so as to provide additional features such as threaded discussions that are easily searchable. --JWSchmidt 22:46, 30 September 2006 (UTC)

 * "I completely agree with you that each topic should have a virtual classroom with it so that students can interact, since the classroom weather virtual or real is where the true learning takes place. :)"

title: Wikiversity talk:Main Page/Archive 2


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World Literature 1

Welcome to World Literature 1

World Literature 1 guides you through what are considered by many scholars to be the most important foundation literary texts for all human cultures. Once you have read and thought about all these texts, you will have learnt a lot about the way we tell stories and the themes (constant ideas) and images (imaginary pictures) that have influenced writing around the world.

The following course uses the Norton Anthology of World Literature. You can buy or borrow any edition of the book, and begin with volume 1.

Unit 1. The Beginning of Narrative: The Epic of Gilgamesh. Read the introduction to ancient literatures of the Middle East, and then tackle the Gilgamesh. It's probably easiest to read it chapter by chapter.

As you are reading, make notes to yourself about how the story works. Which characters and plot devices seem familiar to you from other stories? In particular you might compare the Gilgamesh to the plot and characters of STAR WARS and/or SPIDERMAN or BATMAN BEGINS. What characters and/or plot developments seem different?

Unit 1 a. The Old Testament. Compare the style of writing with the Gilgamesh. Eric Auerbach argues that the Old Testament is written in a short-hand kind of style, because it's addressed to an audience who already know the stories thoroughly and therefore they need brief "reminders", which the tellers of the stories can then expand upon in discussion.

One of the themes in the epic of Gilgamesh is the meaning of life. Gilgamesh at the beginning is depicted as a tyrant but transforms into a good king after his first battle with Enkidu showing that one has the chance to transform their way of life. He’s then driven by the aspiration of making his name remembered forever, ultimately leading to Enkidu’s death as punishment for his arrogance. This makes Gilgamesh face his mortality making him obsessed with seeking the secret to immortality, ending up losing his key to an everlasting life thus accepting his mortality. Civilization: Enkidu, though a mirror to Gilgamesh, he is an innocent version of mankind living in harmony with nature like an animal. Enkidu’s sexual encounter with Shamhat for seven days and six nights plays a civilizing role as she teaches him the way of love, language and other human characters Pride: From the beginning, Gilgamesh is depicted to proud and this can be attributed to him being one-third man and two-third god leading to the gods deciding to teach him a lesson by sending Enkidu, his mirror, to humble him. Even after forming a friendship with Enkidu, though he transforms to be a good king, his quest to the forest whereby they killed Humbaba is motivated by pride which leads to Enkidu’s death.

Various archetypes that can be found in the narrative, some of them include the; ruler, hero, explorer, villain, and the sidekick. Gilgamesh at the beginning of the narrative is a tyrannical ruler; he forced his subjects to excessive labor, ordered them to go on battle constantly, and raped every woman he was interested in. Although flawed so much, he can transform into a good king and all this is due to his encounter/ friendship that ensued with Enkidu. Thus Enkidu can be depicted as the hero type as he challenged Gilgamesh enabling him to be a good person and generally a king. Gilgamesh is also depicted as an explorer; he was the one with the idea of going into the “land of Cedars” and together with Enkidu they traveled to the forest; after Enkidu’s death, he went on a mission to seek immortality which he, unfortunately, did not achieve. Humbaba, the forest protector is depicted as the villain as he cast mortals (by killing them) out of the forest, thus being taken as the evil character though that is his role as the guardian of the forest. One may say that Enkidu is a sidekick. He was on Gilgamesh side during battles, and without him, Gilgamesh would not have been able to defeat any of the people/ creatures he fought. Enkidu did do a lot of work and took little credit for them and when the narrative needed a scapegoat, he was used as one even though the mistake being punished was not his doing. These archetypes aid us to understand the Gilgamesh way of life; his reasoning on a decision . Gilgamesh should be included in a college course on World Literature as it is a significant literary work since it is the world’s oldest surviving written poems and can, therefore, be termed as a source of ancient events. The story is dated to about more than 4,000 years ago giving a picture of how Mesopotamia was in the Ancient days: the narrative gives details of civilization in that era. Mesopotamia is known as the “cradle of human civilization” since the first cities began there. Gilgamesh portrays civilization to have both positives and negatives helping one to realize the ambiguity in civilization during that era and determine if it still applies to this era. The narrative also shows the reader the way of life which is depicted by Gilgamesh life and his seek of immortality. The author depicts how in life people search for wholeness and in the midst of it become confused; showing that life, death, and one’s realization should be united. The epic of Gilgamesh is also a captivating source of the Great Floods and Human beliefs. The narrative mentions the Great Floods which are also mentioned in the Bible which is an interesting detail for historians in determining whether this event was real or not. The belief and inclusion of the gods in the poem gives the idea of human beliefs being there from ancient times.

title: World Literature 1


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Talk:PHP/Variables

Factual errors
The example and the text in this section is wrong. The second example will work without any errors (in any configuration, even if E_ALL is set). Instead, the result will be 4 * pi, because the interpreter will cast the string to an numeric value, which means, that every char from the beginning of the string will be threated as a numeric value until an invalid character occurs.
 * Variable conversion

Samples:

This behaviour is well documented, see PHP Manual.

 * Declaration

First, the C++ example is wrong. The string value should be double-quoted, because single-quotes have a different meaning in C. However, in C++ you would simply write something like string msg = "Stuff"; which is quite straightforward.

The second PHP example is also wrong, because the keyword "var" can only be used within PHP4 classes and not in global context. To "declare" a variable in PHP you have to assign a value, e.g. $a = 0. --The preceding unsigned comment was written by 84.44.172.234 (talk - contribs)
 * Thankyou for your suggestions. If you find something is wrong with the article, go ahead and fix it! Just click 'edit' at the top of the page. I'm not quite sure what you mean by the variable conversion issue - '42' * pi works perfectly and multiplies pi by 42, not 4. --Draicone (talk) 00:24, 3 October 2006 (UTC)

 * I mean the second example, not the first one. It says, that '4string2' * pi would lead to an error or a warning, but this is wrong. Instead, PHP will cast the string like i mentioned in the first comment.

 * Comparison C++ and PHP

The comparison of PHP and C++ variable declaration (in fact, what you show is declaration plus intialization) is completely useless and misleading: In the PHP example you simply show a variable initialization, while in C++ you show a function (why??), a declaration of a variable and an assignment statement. You can't compare these two examples. The equivalent C++ code (using integral types) would be like: char* a = "Hello"; ...which is as simple and straightforward as the PHP code.

Automagically
Automagically? That's not a word! :-) --Jimmytharpe 18:07, 29 January 2007 (UTC)

title: Talk:PHP/Variables


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Contact resistance in transistors

Background
Contact resistance in transistors is the resistance between the metal and silicon in a contact. This is due to the difference in the bandgap energies between the two materials. The closer the bandgap the less resistance.

Early on in the semiconductor world, Aluminium was used as the metal, however this was replaced by copper which provided a better contact resistance.

If the example of a 1 micron and a 0.1 micron manufacturing process with aluminum contacts is taken into consideration it will become apparently clear how important this is becoming. The resistance of the device (R) is equal to the contact resistance (PC) divided by the area (A). For aluminum to heavily doped silicon the contact resistance is around 1x10-6 ohms cm2.

For the 1 micron example the area will be (1x10-4)2 which equals 1x10-8 cm2 thus the resistance will equal 1x10-6 / 1x10-8 which will equal 100 ohms. The 0.1 micron example the area will be (1x10-5)2 which equals 1x10-10 cm2 thus the resistance will equal 1x10-6 / 1x10-10 which will equal 10,000 ohms.

Measurements on the metal to find the contact resistance has been the Cross bridge Kelvin Resistor, however in small devices it has been noted that the results have not been very acurate using the standard calculation. Understanding, better calculations and a new measuring technique was introduced in a 2002 paper "A simple approach to understanding measurement errors in the cross-bridge Kelvin resistor and a new pattern for measurements of specific contact resistivity (Mizuki Ono, Akira Nishiyama, Akira Toriumi : Solid-State Electronics 46 (2002) 1325-1331)".

Cross Bridge Kelvin Resistor (CKR)
Above shows the structure of the CKR. In an ideal situation the arm's of the silicon and metal layers would be the same width of the contact but due to alignment margins this is impossible under normal manufacturing processes. It was seen that by moving the contact area around the arm's would provide different resistance measurements which has provided a lot of mystery around the device until the 2002 paper by Mizuki Ono. This paper showed how the effect of the extra silicon affected the results and hence why the measurements changed when the contact area was moved around.

Ono Equation
Pc= specific contact resistivity           Ps= sheet resistance

Using this equation, we can more accuratly calculate the contact resistance for the metal's using the standard CKR and hence are able to use premade version by accuratly finding out the measuremnets required using an appropriate electron microscope.

Ono Design
This design was created as a replacement to the CKR, due to the large length the design irradicates a lot of the errors, the CKR is prone to, and thus gives a more accurate result. For this to work, the length L must be longer than (Pc/Ps)1/2 in which case the equation I=(W.Vo)/sqrroot(PcPs) where Vo is the voltage at the right edge of the contact hole. Vo can be found by extrapolating the ratio of voltage between the potential terminal of the metal and each potential terminal in the silicon active layer (ie Vsa, Vsb and Vsc).

Additional files
[[Media:contactresistance.sxw]] - my Final year project report on contact resistance (At Queens University, belfast) in open office format Contact resistance tool mentioned in final year project is avaible upon request

title: Contact resistance in transistors


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User talk:Puggy

Hello Puggy!

Welcome to Wikiversity! If you decide that you need help, check out Help desk, ask the support staff, or simply ask me on my talk page (you can access it clicking on my pseudo below). Please remember to sign your name on talk pages using four tildes (~~); this will automatically produce your name and the date. I am very interested by microtechnology and micro-electronics, feel free to contact me if you need.

By the way, you need to choose a valid license for this image you have uploaded: Image:Contactresistance1.PNG. Are you the author?

guillom 11:31, 2 October 2006 (UTC)

Image copyright problems

 * This is the image in question. Please provide a license template and source for it. Thanks. – Mike.lifeguard | @en.wb 22:00, 13 February 2008 (UTC)

title: User talk:Puggy


title: File:Contactresistance2.PNG


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User:Rcorreia

Name: Ricardo João Cruz Correia

Homepage:

title: User:Rcorreia


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User talk:Rcorreia

Welcome to Wikiversity. --JWSchmidt 13:53, 2 October 2006 (UTC)

title: User talk:Rcorreia


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User:Axis Mundi

The Japanese language is a complex and beautiful language which is daunting to say the least if you want to learn it. I have been studying the language for three years and am interested in helping to build online language learing tools. I am also interested in helping beginners with any questions they may have. Let me know if I may be of any help.

title: User:Axis Mundi


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User:Sdorrance

Sdorrance is the username for real person [mailto:sam.dorrance@gmail.com Sam Dorrance]

To see what I have been up to on Wikiversity, click here. I also contribute to Wikipedia.

Bio
I am a 22 year old college graduate who lives and works in the Northeast. Although I have a busy schedule, I am consistenly more and more interested in Wikipedia and other Wiki-projects and so I am trying to get myself more familiar and more involved as a somewhat-active member of the community. I don't really like cell-phones, or phones of any kind. Peace and quiet and solitude suit me fine now that college is over.

Interests
Although I was educated at the College of Wooster, at which the philosophy department is largely dedicated to the Analytic tradition, I maintain a broad interest that transcends the analytic/continental boundary - limited only by my distaste for Plato and Ayn Rand. My Junior Thesis was a Kantian critique of development aid, and my Senior Thesis was the creation and evaluation of a Heideggerian philosophical theology.

'''I am new to Wikiversity, so I do not know how much I can help or where I will be able to contribute the most. It will most like be confined to philosophy, however.'''

title: User:Sdorrance


title: File:Various-133-1000cf.jpg


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File:Various-110-1000cf.jpg

Summary
{{Information
 * Description=This image is from the website for the London Borough of Richmond upon Thames and their Classroom of the future.

Dead link
According to this, the funding for "Classroom of the future" ended in 2003. It does not surprise me that this link is now dead.

Try this link. I (John Schmidt) contacted Cristian Marcucci, Assistant Media Officer of their Press Ofice and asked if Wikiversity can use their images. He replied by email, "The images on the Council website are available for public use. Please feel free to use them." }}
 * Source=http://www.richmond.gov.uk/classroom_of_the_future
 * Date=
 * Author=London Borough of Richmond upon Thames
 * Permission=

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User:Smockdotcom

Hi I live in Manchester, England and teach basic maths.

title: User:Smockdotcom


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Wikiversity:Archive

The Wikiversity Archive contains past proposals, ideas and discussions interest into which has died out, for which no consensus was reached or which have become obsolete. Those pages are preserved here for future interest and to avoid having the same discussions over and over. Feel free to add new pages to the archive which are of no more use within the Wikiversity namespace.

Old proposals

 * /Organizing Self-Management/ - created 18th August, 2006; archived 3rd October, 2006
 * No early policies - created 28th August 2006; archived 10th May 2007
 * About - created 19th August 2005; archived 10th May 2007

de:Wikiversity:Archiv el:Βικιεπιστήμιο:Αρχεία συζητήσεων Βικιβήματος

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Template:Historical

This template adds pages to Category:Wikiversity archive.

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Wikiversity:Organizing Wikiversity

 This page is loosely based on an older page: Archive/Organizing Self-Management

This page is for brainstorming, discussing and detailing how Wikiversity is organised, both from a technical point of view (ie custodians) and its relationship with other projects and organisations.

Custodians and maintaining Wikiversity
See main article: the Wikiversity Maintenance Hub

The Wikiversity community appoints people to carry out administrative functions on Wikiversity, for example to delete obsolete pages. More detail can be found at Custodians and current requests at Candidates for Custodianship and Request custodian action.

Wikiversity and Wikimedia
Wikiversity is a project of the Wikimedia Foundation. This means that it is bound within a general community, with a vision of providing the world with access to free information. It also means it has access to a range of people with various expertise, resources (eg. financial, technical), and organisational/community structures to support its ongoing development. Whether Wikiversity wants or needs to set up some sort of structure (such as a committee) to interface with Wikimedia's organisational structure is yet to be fully discussed.

Outreach
As exciting a project as Wikiversity is, it may be desired to enter into collaboration with other organisations/communities/projects. What could Wikiversity be good for and what kinds of projects would be fitting? Please see Wikiversity outreach for details (and A Letter to globaltext.org for an example).

Accreditation
Discussion continues as to whether Wikiversity is to pursue the option of becoming some sort of accredited institution, and how this would be done. See Wikihigh and Accreditation.

Note: The Wikimedia Board of Trustees directed the Wikiversity community not to include credentials and accreditation in the Wikiversity project (see Original proposal).

How you can help right now!

 * 1) De-orphan pages - "Orphaned pages" have no links to them from other pages. You can find appropriate and logical pages to allow others to access orphaned pages and create links to the orphaned pages at those pages.
 * 2) Categorize pages - Uncategorized pages need categories or need to be tagged as uncategorized.
 * 3) Put pages in the right namespace - You can make sure pages are in the proper namespace.
 * 4) Moving (renaming) pages so that they comply with naming conventions can help Wikiversity to be more organized.

Explanation of Structure
A highly visible link to a page explaining Wikiversity structure (Portal>School>Department, etc.) should be on every page somewhere, to help orient confused visitors; it can cause quite a bit of confusion when a user sees "Faculty" and thinks they're going to find a list of people, for example. See: Namespaces.

title: Wikiversity:Organizing Wikiversity


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Template:Wikiversity organization

  Organization of Wikiversity
 * Portal
 * News
 * Chat
 * Policies
 * Discussions

 * Support staff

title: Template:Wikiversity organization


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Nobel Prize in Physiology or Medicine

Welcome to the Wikiversity learning project for the Nobel Prize in Physiology or Medicine.

Participants in this learning project explore the science and practical applications for each year's Nobel Prize in Physiology or Medicine.

The Wikipedia articles about topics related to each Nobel Prize in Physiology or Medicine tens to be very technical descriptions of the underlying science. The goal of this learning project is to complement the Wikipedia articles in two ways. The first goal is to provide a user-friendly introduction to the topic. This means creating learning resources for people who would normally be unable to understand a technical Wikipedia article on the topic. These user-friendly introductions might particularly focus on the practical medical implications behind Nobel Prize-winning scientific research. The second goal is to provide learning resources that allow interested university students to explore the science behind each awarded Nobel Prize in more detail than is possible with the related Wikipedia article.

By year

 * 2006 Awarded to Andrew Z. Fire and Craig C. Mello for their discovery of RNA interference. Learn about RNA interference.

title: Nobel Prize in Physiology or Medicine


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Wikiversity:Centralized discussions

Wikiversity users frequently discuss proposed changes to our project policy; these may take the form of new proposals, amendments to existing policies or guidelines, or straw polls. These discussions generally take place on relevant talk pages. They may also occur at Wikiversity-Beta, on IRC, and on our mailing list.

The Colloquium provides a central area both for giving notice of discussions elsewhere and for debate itself. Despite regular archiving, these pages tend to grow rather lengthy. It's not always easy to know what issues are active.

The box template cent is a centralized list of ongoing policy discussions and polls. It is found on pages where such debate takes place and, of course, you may refer to it directly at any time. Editors maintain this list by adding ongoing discussions and polls and by periodically removing inactive issues.

Usage

 * This page is for explanation of the way in which we use cent.
 * Wikiversity talk:Centralized discussions is for discussion of this process only.
 * Template:Cent contains the actual box content of ongoing policy issues. It should be edited to stay current at all times.
 * Template talk:Cent contains technical documentation of the template as well as discussion of related technical issues.
 * You may create any page of the form Wikiversity talk:Centralized discussion/Some topic if it does not appear that any particular existing talk page is the correct place for a policy-related discussion. Please note that there are a great many talk pages; a very large number of discussions are ongoing. Before creating yet another debate page, check to see that the topic is not already under discussion elsewhere. Search the project for keywords related to the topic in question.
 * Discussions are summarized at Centralized discussion/Conclusions.

Cautions
Like any tool, this may be misused. Kindly exercise restraint, assume good faith, and allow process to take its course. Please don't add new policy ideas indiscriminately; trial balloons are better floated at Colloquium. This template should be reserved for ongoing discussions. Remember, its usefulness is in inverse proportion to its size.

Before joining a debate, it might be wise to gather some background, especially on complex or long-standing issues. Please be courteous to your fellow editors and read existing discussion before adding your own comment. It's hoped that cent will contribute to the opening of policy debate and the broadening of consensus; but of course no good purpose is served by uninformed comment. Stay cool!

title: Wikiversity:Centralized discussions


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Wikiversity:Candidates for Custodianship/SB Johnny

This is an archive of community discussion related to the nomination for full custodianship of User:SB Johnny.

The period for comments on this nomination starts on September 27, 2006, at 17:28 UTC and ends on October 2, 2006, at 17:28 UTC.
 * Mentor:
 * Evaluation
 * I nominate SB Johnny for full custodianship. SB Johnny has been a probationary custodian since August 27, 2006. SB Johnny is also an administrator at Wikibooks and has helped coordinate the transfer of Wikiversity content from Wikibooks to Wikiversity. This coordination has been facilitated by SB Johnny's participation at IRC freenode #wikiversity-en, Colloquium and Import. After having served the community during the probationary period, SB Johnny should be confirmed by the Wikiversity community as a custodian. --JWSchmidt 02:28, 27 September 2006 (UTC)
 * Comments
 * I fully support SB Johnny. I've met SB several times on IRC and have watched his actions on Wikiversity. I've only seen good work conducted in a professional and courteous manner. I think SB Johnny would be an excellent custodian. -- sebmol ? 06:39, 27 September 2006 (UTC)
 * Full support too ; good'ol'fellow. Let's make his broom « official ». guillom 17:07, 28 September 2006 (UTC)
 * Good user. Full support! --HappyCamper 01:14, 29 September 2006 (UTC)
 * Full support!-- digital  _  me   03:14, 29 September 2006 (UTC)
 * I strongly support the user. He has made some excellent contributions to wikiversity and I am sure he will be an excellent custodian. --Draicone (talk) 03:41, 29 September 2006 (UTC)
 * Full support - SB_Johnny is a great and solid contributor and custodian. Cormaggio 13:32, 3 October 2006 (UTC)

Closing comments
All community comments supported full custodianship for User:SB Johnny after a one month probationary period ending 27 September, 2006. The period for comments on this nomination was from September 27, 2006, at 17:28 UTC and ends on October 2, 2006, at 17:28 UTC. SB Johnny became a community-approved custodian on October 3, 2006. --JWSchmidt 23:09, 3 October 2006 (UTC)

I'm an admin on wikibooks, and an old-school vandal/spam fighter and newpage patroller on en-WP. I'd be happy to help out with the pagemove process, etc., then help keep an eye on things later. --SB_Johnny | talk 13:27, 27 August 2006 (UTC)

 * JWSchmidt be a wonderful mentor, thanks.--SB_Johnny | talk 13:36, 27 August 2006 (UTC)
 * JWSchmidt be a wonderful mentor, thanks.--SB_Johnny | talk 13:36, 27 August 2006 (UTC)

 * was made a probationary custodian on 27 August 2006; mentor = JWSchmidt.


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RNA interference

The Nobel Prize in Physiology or Medicine in 2006 was awarded to Andrew Z. Fire and Craig C. Mello for their research on RNA interference. The goal of this learning project is to complement the Wikipedia article about RNA interference in two ways. The first goal is to provide a user-friendly introduction to the topic. This means providing learning resources for people who would normally be unable to understand a technical Wikipedia article on the topic of RNA interference. The second goal is to provide learning resources that allow interested university students to collaboratively explore the science behind each awarded Nobel Prize in more detail than is possible with the related Wikipedia article. If you have not done so already, take a look at the Wikipedia article about RNA interference then select one of these learning paths:

 * 1) Explore a user-friendly introduction to the practical medical implications of RNA interference that arise from the Nobel Prize-winning scientific research of Andrew Z. Fire and Craig C. Mello.
 * 2) If you were able to read and appreciate the Wikipedia article about RNA interference then continue reading below and participate in further exploration of this subject.

RNA interference was discovered as a mechanism used by cells for regulating gene expression. This discovery has quickly resulted in the widespread use of artificial interfering RNAs as an important laboratory research technique for altering the amount of specific proteins inside cells. There is also active study of the potential value of RNA interference for medical applications.

Short review: RNA interference in cells

This section and the next few sections briefly introduce RNA interference (RNAi) and will orient you towards the activities. See the Wikipedia article about RNA interference for more a more detailed introduction to RNAi.

The normal function of RNA interference inside cells depends on the production of double stranded RNA (dsRNA). Base pair-complementary RNA strands (ssRNA) can be produced by transcription of both template DNA strands of some genes (Figure 1). In other cases, the protein-coding RNA sense strand might be produced by a virus and the antisense RNA strand produced by the host cell. The sense and antisense RNA strands form double strand RNA (Figure 2, top) that is processed to small (about 20 base pairs long) inhibitory RNA (siRNA). The siRNA can form a molecular complex with proteins that first strip away the sense strand of RNA, making the antisense inhibitory RNA (iRNA) available for base pairing with messenger RNA (mRNA). This targets a specific mRNA for destruction (Figure 3), resulting in inhibition of the biological function that would otherwise be served by the protein coded for by the mRNA.

There had long been interest in the idea that it might be possible to alter gene expression by using single strands of nucleic acid that might base pair hybridize with a specific target in cells. However, it was only in 1998 that experiments were described showing the unexpected power of double stranded RNA to block gene expression. The experimental system used was the worm Caenorhabditis elegans. This was a useful experimental system because the developmental orgin of all of this organism's cells is known and it is possible to inject RNA into early embryos and observe changes in the pattern of development.

Protection against viruses
An important aspect of RNA interference is its role in protecting organisms from some deleterious effects of viruses. Such a role for RNA interference was first found in plants, but has also been found in some animals.

Gene expression knockdown experiments
RNA interference is now a widely used biology research technique that can be applied to both cultured cells and whole animals. RNA interference can be used to selectively reduce the level of expression of a specific protein. Clues to the function of the protein can be obtained by observing changes in cell or organism behavior after knockdown of expression.

Medical applications
It has been suggested that knockdown of expression of proteins by virus-delivered siRNA might be effective for future treatments of Amyotrophic lateral sclerosis  and other neurodegenerative diseases. Working with laboratory mice as an experimental model system for the human disease ALS, Miller et al showed that loss of muscle function could be slowed using RNA interference.

Detailed Review
RNAi is discovered as a defense system to prevent attack of viral and parasitic RNA. Later on, other fuctions of its emerged, like endogeneous gene regulation. This system is able to seen in Caenorhabditis elegans, Drosophila, yeast as well as can be done in mammals. Main mechanism of RNAi is revealed by Fire and Melo. It is used in many laboratories to induce gene silencing in organisms by delivering appropriate dsRNA (double stranded RNA). RNAi can be utilized as an analysis tool to understand function of genes therefore let us to obtain an evolutionary view. It is also possible to determine mutant genes, which cause death of the organism, via RNAi. RNAi centered techniques for full genomic screen provides oppurtunity to identify specific genes via testing a given trait with high trustability. CRISPR interference is an alternative for RNAi in prokaryotes. CRISPR and RNA interference mainly differ at structures of the components, however, pathways share similarities. Increased studies ulliminated the way that RNAi work and let scientist to utlize it better.

Basic Mechanism of RNAi in Mammals
Three main components of RNAi silensing includes Drosha, Dicer and Argonaute (Ago) proteins. Both Drosha and Dicer are the members of RNAase III family. They have ability to cut dsRNA by leaving 5’ phosphate head and 2 nt (nucleotide) overhang at 3’ end. With this property, they are responsible for processing of newly transcribed small hairpin non-coding RNAs to smaller pieces. The pieces are 21- 25 nt dsRNAs. Drosha only found in animal cells. After, one of the strands of 21- 25 nt dsRNAs loaded into RISC (RNA induced silensing complex). This complex is the direct effector of mRNA translational inhibition and it is mainly based on members of Argonaute (Ago) protein family. Slicing activity of Ago is dependent to perfect complementarity of guide RNA with target RNA. Imperfectly matching leads to generation of several scenario containing translational inhibition, prevention of de- adenylation and nuclease degradation by P body. While each scenerio is possible alone itself, also combination of them can be observed. Some Ago including complexes may provide inhibition of transcripition via affecting chromatin structure or causing modification on histone proteins .Basic mechanism of post-transcriptional gene silencing in mammals is given step by step in figures named Part 1, Part 2, Part 3, Part 4, Part 5.

RNAi in other Organisms
RNA interference is an highly conserved mechanism but components of the system may be distinct from one organism to another, even some contributers of the mechanism may be deficient in some cases.

C. elegans: C. elegans is a transparent roundworm. It has 1mm length. Diet of its consists of bacteria. By means of the efforts of Dr. Sydney Brenner, this animal became one of the strongest model organism. Ago- guide RNA interraction forms the base of RISC(RNA induced silencing complex). Ago has two extremely characteristic domain called PAZ(PIWI/ Ago/ Zwille) and Piwi. These domains are responsible for holding guide RNA in a way that does not close the side which base pairing occurs with target mRNA. In PIWI, catalytic role is borne by DDH motif which is similar to RNase H family catalytic. Problem on the residues of DDH on Ago2 results in cancellation of slicing of target.

RDE- 1 is a type of Ago in C. elegans, works with rde- 4. Without rde-4, decline on siRNA level happens. RDE- 4 has a binding motif which provides better interraction with long dsRNA, instead of short ones like siRNA. This protein is not just linked with rde- 1 and dsRNA, also have connection with the other elements of RNAi. Rde- 4’ s main responsibility is recognition of long dsRNA and presentation of it to DCR- 1.

SID- 1, a type of membrane protein of C. elegans, provides passage of exogeneous dsRNA, into C. elegans cytoplasm. Homologs of SID- 1 found in mammals however not found in Drosophila. MicroRNA has crucial effects on differentiation and time of development of this organism. Different organisms have different anatomies and physiologies which cause application of separate techniques to force organism to accept service of dsRNA. Introduction of dsRNA to C. elegans can be achieved via several methods. These methods are:

a)	Direct injection. dsRNA including solution is ejected to the body cavity. In this method, RNAi response arises throughout the body.

b)	Production of trangenic amimal that express target dsRNA. The technique is limited with the tissue that the technique applied.

c)	Immersion of the organism to the solution of dsRNA. Ingestion of RNAs leads generation of RNAi response.

d)	Feeeding with bacteria which are genetically modified to produce target dsRNA.

Drosophila: Drosophila genus hosts one of the model organism named Drosophila melanogaster.

In Drosophila, dicer- 1 and dicer- 2 found as paralogs of Dicer. As dicer- 1 plays role in generation of miRNAs, dicer- 2 included in synthesis of siRNAs. Explanation of this discrimination originates from structural differences. While dcr- 1 does not have helicase domain, dcr-2 suffers from absence of PAZ domain. However, in terms of function, dicer- 1 and dicer- 2 don’ t have a thick boundary wall that separates them from each other. Both of the enzymes are obligatory for functioning of the siRNA mediated destruction of target mRNA and gene silencing. PAZ domain of Dicer works with RNase III domains in order to provide determination of 3’ overhang ends of target RNAs. RNase IIIa and RNase IIIb gather to take over catalytic process that dicer is responsible for. Linkage of these domains with Ago occurs at the side of PIWI domain of Ago. Efficiency of the enzyme is highly dependent to 3’ overhang nucleotide sequence After Dicer processing, small noncoding RNAs passed into RISC.

List of members belongs to RISC of Drosophila  :
 * Ago2
 * dFXR (Drosophila Ortholog of Fragile X Mental Retardation Protein)
 * VIG (Vasa Intronic Gene)
 * Tudor- SN
 * R2D2
 * Aubergine
 * Armitage- RNA helicase
 * Others

While RISC loading occurs, guide strand selection is carried out by the help of R2D2 protein. As passenger strand is gong to be degraded, other one used as a guide. Identification of passenger and guide strand of siRNA is achieved accourding to thermostability of ends of strands. At the time of guide strand selection, Dicer connects to less stable 5’ end of siRNA as R2D2 binds to more stable one, in thermodynamicity. Less stable ended one loaded into RISC. In Drosophila, separation of passenger and guide strand is carried out by Ago2.

Usage of less stable strand on RISC lowers, even minimize, posibility of off targeting. PAZ of Ago contact with 3’ end of siRNA while PIWI domain makes connection both with RNase III domains of Dicer and phosphate headed end of siRNA single strand. PAZ affinity towards 3’ overhangs originated from aromatic residues on it. Different members of Ago family bind to distinct siRNAs. All of four Ago of mammalian cells can connect to miRNA. As opposite to mammals, Drosophila melanogaster has only Ago1 in its miRNA pathway.

Drosophila has 3 type of siRNA based RISC as shown in table located below.

The I Factor is the structure that is the cause of the disorder named as Hybrid Dysgenesis, in Drosophila melanogaster. This disorder contains abnormalities mainly based on high mutation rate. I Factor repression is maternal and have long term effect. Repression of the factor carried out by the help of RNAi. One strong scenerio about it suggests siRNAs for repression originated from egg cytoplasm. Another elements occurs to cause other types of Hybrid Dysgenesis. One of them is called P element, which are DNA transposons. High level of transposible element activity drives cell to death. P element is under the control of RNA mediated mechanism.

PEV (Position Effect Variegation) is the result of chromosomal rearrangement of the place of euchromatic gene. The euchromatic gene transferred next to heterochromatin and euchromatic characteristics of the translocated gene disappears, gene become silenced. PEV is well studied in D. melaogaster eye and body pigments. PEV is mainly related with propagation of methylation.

HP1 based silencing is achieved by the help of RNAi components. Expression of transposable elements of Drosophila is majorly controlled at transcription level. RNAi connected to gene silencing via Polycomp proteins in Drosophila. Polycomb response elements helps silencing via employing Polycomb complex. Stuck at RNAi machinary provoke rise in transcription of heterochromatic genes.

S. pombe: Although Schizosaccharomyces pombe is a fungus, because of its high similarities with other eukaryotes, it became a good choice to work on some cellular events including RNAi based heterochromatin generation. In S. pombe, also known as fission yeast, RNAi has considerable effects on the formation of heterochromatin. Centromers, telomeres, locus of mating- type and ribosomal DNA are the regions under the control of RNAi mechanism in terms of chromatin modification.

Heterochromatin is the name of sites exposured to methylation on lysine 9 of H3, a type of histone protein. Methylation occurs with the help of Clr4, a histone methyltransferase. Number of methyl inserted to H3 can vary from one to three. Loss of Clr4 directly means that loss of H3K9 methylation. Clr4 has chromo and SET domain. SET plays role in the methylation. Abnormality on SET domain causes results in changes on the methylation level at some loci of S. pombe.

Clr4 also mediates Swi 6 to bind to related loci. Methyl addition to lysine 9 residue lets Swi 6, a chromo domain protein in fission yeast, to link to H3 by the help of its chromo domain. Dimerization of Swi 6 proteins may lead other proteins to associate with Swi 6 via interraction surface resulted from dimerization.

Acetylation of target residue blocks methyl insertion. Therefore histone deacetylase activity is needed. This requirement is carried out by the enzymes of HDACs (histone deacetylases). Sir2 and Clr3 are the examples of HDACs with Clr6, which has broad target catalog that makes it crucial.

Presence of RNAi mechanism is as significant as functioning of Clr4 and Swi6. RITS (RNA induced transcriptional silencing complex) and RDRC (RNA directed RNA polymerase complex) are the two complexes that are the components RNAi mediated generation of heterochromatin in Schizosaccharomyces pombe. RITS composes of Ago1, Chp1 and Tas3 besides siRNA bound to Ago1. In RITS, Chp1 is responsible for interraction of the RITS with H3K9me2 (2 methyl added to lysine 9 of H3) via its chromo domain. In the absence of one or more components of RITS, remainings can associate but activities of this “half” RITS is not capable of doing activities of fully equiped RITS. Dcr1 and Clr4 are required, alongside Rdp1 (RNA dependent RNA polymerase 1) catalytic activity, for RDRC- RITS linkage. Relation of RITS with both siRNA biogenesis and chromatin structural changes is an evidence of presence of feedback mechanism working between RNAi and chromatin modification. H3K9 methylation at the telomeric, centromeric and mating- type region is not totally cancelled out in the absence of RNAi. This is because of RNAi independent pathways in S. pombe, like Taz1 protein in telomeres. Experiments suggest that other chromo protein Chp2 takes over the job of Chp1 at related loci.

Heterochromatin has impotance on mating- type determination. Abnormalities found in the heterochromation structure of mating- type switching genes, can drive haploid cell of S. pombe to death.

Arabidopsis: In plants, the place for Drosha is filled with the Dicer homolog protein called Dicer- like 1. Plants produce four Dicer Like Proteins, abbreviated as dcl. Four of each bears separate jobs. Processes of pre- miRNAs (precursor miRNAs) are carried out via dcl- 1 while dcl- 2 is responsible for production of siRNA used in defense mechanism against to viruses. Dcl- 3 generates siRNAs that are the part of chromatin modification and silencing at transcription level. The last dcl enzyme named dcl- 4 cares formation of trans- acting siRNAs which are involved in regulation of accumulation mRNAs.

Dcl- 1 is escorted by Hyponatic Leaves1 (HYL1) and Serrate (SE) to function in Arabidopsis. While HYL1 is a dsRNA binding protein , SE is the encoder of C2H2 zinc finger protein, which affects miRNAs’ relation with leaf polarity in Arabidopsis. It is current truth that SE and HYL interracts. Dcl- 2, 3 ,4 are mainly involved in siRNA generation pathway. Dcl- 1 also has crucial missions in the formation of natural antisense short interfering RNAs. Thus, this event is an example demonstrates dcl- 1 is not restricted with miRNA genesis.

Before process of Dcl, Arabidopsis utilizes HASTY, homolog of exportin 5, in order to export miRNA from nucleus.

Methylation of miRNAs is carried out via HEN1 protein as a general step of miRNA biogenesis in plants. Methylation happens after Dcl functions. 2 overhang of 3’ end of miRNA duplex is favored substrate for HEN1. Change on the size of overhang may cause to dramatically decline or stop of HEN1 methylation acitivity. HEN1 functions regardless of the 5’ end characteristics. In addition to 3’ end nucleotides, 2’ OH of end nucleotide at 3’ end is significant determinant of methyl addition. Methyl is added to this 2’ OH. Efficiency of methylation changes with the length of miRNA, in vitro. Again in vitro, HEN1 has ability to methylate both siRNA and miRNA duplexes. Methylated miRNA enters RISC after processed by Ago for separation of passenger strand from the guide one.

Most of the Ago from Arabidopsis are capable of slicing target RNA. As opposite to animals, plants have miRNAs capable of destructing intended mRNA when perfect or barely perfect matching between mRNA and guide strand is provided. At 3’ end of mRNA, just after translational termination codon, a region called 3’ untranslated region is localized, abbraveated as 3’ UTR. This region contains miRNA response elements (MREs). In mRNA metabolism of plants, interraction between miRNA and MREs determines mRNA will be degradaded or not while in animals, this relation just may cause inhibition of translation.

MiRNA cleavage remains smaller RNA particles which will be degraded by exonucleases, like XRN4. Before exonuclease activity, a few modification like insertion of adeninosine or uridine to the end of target molecule can be required.

Plants utilizes its phloem or/and plasmodesmata to propagate RNAi response to other cells of the plant body. Unlike animal miRNA genes, those ones belongs to plants are intergenic and do not exhibit co- transcription and/or translation. Production of miRNA controlled via feedback mechanism that is mediated by means of miRISC activity on mRNAs of Dcl- 1 and RISC components. It is thought that miRNA evolves fast in plants. This idea is supported with the observation that most of miRNA of Arabidopsis are nonconserved in poplar and rice.

Drosha
In human, DGCR8 and Drosha associates with each other.

Dicer
Insertion of ATP triggers production of siRNA by interraction of ATP with helicase/ATPase domain located on one the Dicer of Drosophila and Dicer of C. elegans. Although mammalian Dicer has helicase/ATPase domain, no influential effect of ATP occurs, in the absence of Dicer in mammalian cells does not inhibits RISC activity.

Two example of dsRNA bindind domained proteins, that associate with human Dicer, are TRBP and PACT. TRBP is an effective component for optimum silencing by siRNAs and endogeneous miRNAs. Additionally, the proten contributesto regulation of some other mechanisms like control of cell growth.

Dicer works under the presence of the Mg2+ which can be replaced with Co2+ or Mn2+. Dicer even can process dsRNA that have blocked ends with RNA tetraloop or DNA- RNA duplexes. It converts these ends to 2nt overhang 3’ ends. After that it continues its normal pathway.

Human Dicer works regardless of ATP. This condition is more or less same for UTP, TTP, GTP etc. and nonhyrolyzable ATP analogs. In chicken- human hybrid cells, lack of Dicer is ended up with the mislocation of RAD1 and BupR1 heterochromatin related proteins.

Efficieny of Dicer- 1 enzyme in Drosophila is dependent to Loqs, a type of protein.

Dicer- 2 from Drosophila melanogaster cannot function without ATP  as other RNA helicases are not able to do, too. Functioning of Girdia intestinalis Dicer void of helicase domain demonstrates dispensability of the domain for working of the enzyme.

An extremely conserved part of RNAase III family proteins is called endonuclease domain. It is found in the form of tightly associated dimer. Because of dimerization, a space form between monomers which dsRNA molecule sits. The space is named “catalytic valley”. The valley carries negative charge on itself which lets magnessium ion to interract. Magnessium ions locate close to ends of this valley.

RNase IIIa domain cuts from 3’ end of one strand of dsRNA while RNase IIIb refers to cut from 5’ end of opposite strand.

In Girdia, distance between PAZ and RIIIDs domains is equivalent to the length of cleavage product. Thus it is thought that length of miRNAs and siRNAs determined by structure of Dicer.

Ago
PIWI domain is the slicer of Ago in RISC. PAZ of Ago contact with 3’ end of siRNA while PIWI domain makes connection both with RNase III domains of Dicer and phosphate headed end of siRNA single strand. PAZ affinity towards 3’ overhangs originated from aromatic residues on it. Different members of Ago family bind to distinct siRNAs.

Intrerraction between Ago and Dicer is achieved by the help of Hsp90 protein. This linkage can be disrupted via block of Hsp90 by means of Hsp inhibitors.

RISC
Size of overhangs is one of the most important factor affecting the RNAi activity. As even change in phoshate head of siRNA may result in severe effects on the mechanism of RNAi, its absence means directly loss of RISC stability.

Available Mg2+ is an obligation for catalytic activity of RISC.

RDRP
RdRP primarily belongs to viruses. It directly contributes to viral gene transcription and replication, in viral systems. In general, RdRP carries 4 main domain, palm ,fingers, thumb and N terminal domain that connects fingers to thumb domain.

It has cleft for sitting of template RNA strand. This template creates base pairing with small part of primer RNA

RdRP, in general, known as a type of error prone polymerase.

Details of RNAi in mammals
Neither sense nor antisense strand of dsRNA alone can trigger RNAi response. Both strands together is needed to do it.

Generally, transcripts of miRNA genes, pri- miRNAs, have at least 1000 nt. After operation of DGRC8/DROSHA on pri- miRNA, pre- miRNAs are gained with 60- 70 nt length, 2nt overhang at both side and 10 nt loop at one side. All of these process happen in the nucleus.

Seed sequence is the region of off-target mRNA that match with 6-7 nt of siRNA sequence. If siRNA on RISC has seed sequence coomplementary to 3’ UTR of mRNA, it behaves as miRNA and prevents transcription of that mRNA, which is not real target RNA molecule. Off target effects could drive cell to death by cellular toxicity. H3K9 and H3K7 of mammalian cells are the targets of methyl addition via siRNA directed mechanism. With this methylation silencing at the level of transcription achieved at related si- RNA targetted promoter sequences.

Vigilin is one of the RNAi protein involved in the relation of RNAi with heterochromatin formation. DNA repair protein DNA- PK (DNA Protein Kinase) behaves like a bridge between vigilin and HP1 (Heterochromatin Protein 1). With its kinase activity, vigilin complex promotes phosphorylation of HP1.

DNA- PK is not only repair protein that vigilin interracts. Another “bridge” protein is ATM which found in DNA Damage Response signaling. Drosophila has ortholog of ATM called dATM that helps HP1 to sit true place on telomeres.

Synthetic shRNAs (small hairpin RNAs), which has 25- 29 nt long and are 2’ overhanged at 3’ ends, are more effective than siRNAs that have the same target sequence. The main problem of the usage of these shRNAs and siRNAs is that they cannot generate permenant or inducible slincing on the cells of mammals. The reason for transient effect is lack steps of amplication process of RNAi involved in another systems. Each cell division and formation of each RISC declines the nnumber of siRNAs whose effect is not amplified. However some solutions are available so as to enable stable gene silencing in mammalian cells.

RNAi machinary is capable of realizing even one nucleotide difference between two mRNA molecule. Because of this high specifity, it can be used for allele- specific purposes means that while it affects mutated allele expression, normal allele expression remains fixed.

As a result of its weight and charge siRNA is not able to pass freely biological barriers. In order to overcome this issue, different methods are developed. 4 main groups of delivery techniques can be counted as:

 * 1)  Lipid based techniques
 * 2)  With high level similarity to lipid based ones, polymer based methods
 * 3)  Naked delivery methods
 * 4)  Peptid based techniques

Succesfull transfection of siRNAs can be reached by electroporation, which causes toxicity, or using microsponge , liposomes or dendrimers.

SiRNAs preferentially created with UU or TT overhangs to be recognized by RNAi mechanism.

2’ – O- (2- methoxyethyl) modification at second base importanly declines off targetting. Utilization of LNAs (Locked Nucleic Acids) as a modification on siRNA is another option to strengthen the RNAi inducer molecule.

Internal modifications are not sufficient at introduction of inducer RNA to central nervous system cells.

Immune system and RNAi
Long dsRNA also triggers sequence independent interferon response (Figure 7 and Figure 8) in addition to possibility of RNAi mechanism induction, in mammalian cells.

Interferons (IFNs) are the cytokines capable of influencing multiple cell types. IFN is dramatically significant at communication among cells throughout innate immune responses beside adaptive ones. It primarily targets bacterial and viral infections alongside neoplastic transformation. INFs catogorized in to type I and type II IFN in terms of the way that they regulate immune components.

Type II IFN contains IFN- γ. IFN- γ sits at the center of immune responses because expression of molecules used in intercellular communication and cellular interractions is under the control of its. At the time of the infection, Dendrite cells and monocytes are alerted by molecules located on the cell wall of the bacteria. Then alerted cells activates T and NK (Natural Killer) cells to produce and release IFN- γ.

MHC (Major Histocompatibility Complex) class I cell surface structures have responsibility to present an order of peptide epitopes to CD8+ T cells. Cells carrying proper epitopes for CD8+ cell recognition interracts with T cell and cause release of IFN- γ.

Released IFN- γ connects its receptor on the target cells and leads dimerization of IFN- γ- R1 and IFN- γ- R2 subunits of the receptor. Further, dimerization causes phosphorylation of JAK1 and JAK2 receoptor associated kinases. Then JAK1 and JAK2 phosphorylates STAT1 monomers to make them proper for dimerization. Dimerized STAT1 goes to inside of nucleus so as to activate transcription of some components found in the immune response.

IFN- γ has a negative feedback mechanism based on SOCS1. SOCS1 which is awaken by IFN- γ, prevents JAK1 and JAK2 activity, thus further steps extending until transcripitional activation fails.

Other machinaries exists in order to regulate IFN- γ signaling pathway. These are mainly based on inhibiting the work of proteins included in IFN- γ signaling and MHC class I path. Block of MHC class I pathway means loss of presentation of abnormal cell to CD8+ T cells, therefore IFN- γ even is not secreted from the T cell.

MiRNAs are also said to be regulatory molecules of innate and adaptive immune system. At many stages of tumor, aberrancies on miRNA metabolism is determined. MiRNAs may contribute or repress the tumor. They achieve this by influencing APM (Antigen Presenting Machinary), which makes protein ready for presentation to immune cells , and regulating IFN- γ signaling proteins.

IFN- γ is able to interfere miRNA metabolism whereas miRNA metabolism can disrupt IFN- γ synthesis, seen in NK cells.

Immune system disorders orginate from overexpression of immune factors. Targetting these factors are able to recover disorders related to immunity.

If the siRNA carries danger motif (5’- GUCCUUCAA – 3’) TLR7 dependent immune response happens via recognition of siRNA by TLR7 receptor on plasmocytoid dendritic cells. Stoppage of this type immune system alertion can be provided by means of chemical modifications or nanopartical coating the inducer RNA. Because TLRs expression is dependent to cell type, immune respose against siRNA is also depends on cell type.

PiRNA
PiRNAs has distinct size and end modification from siRNAs as well as from miRNAs.

PiRNAs’ biogenesis is dicer independent. Activity area of piRNA includes germ- line development, stem cell recovery, transposon blocking and epigenetic regulation. They play role in both posttranscriptional and chromatin level reactions. Though it is not known how piRNAs are produced and amplified, existence of their slicing ability is a known fact.

Long Noncoding RNAs
Long noncoding RNAs (lncRNAs) differ from siRNAs, miRNAs and piRNAs (piwi- interracting RNAs) via their large size (<200 nt).

LncRNAs participates in transcriptional activation, inactivation, silencing, by means of epigenetic modifications, and post- transcriptional gene silencing. Predictions and conclusions from experiments suggest that these RNAs functions by interracting with other RNAs, DNA and proteins, including transcription factors.

Noncanonical RNAi Inducers
While canonical siRNAs are being used, some diverge class of siRNAs discovered which do not alert innate immune system. Noncanonical siRNAs, devoid of any modification, have restrictions in usage arises from their weakness against degradation, probability of undiserable guide strand election and induction of interferon response. These siRNAs are larger than canonical ones while smaller than 30 nt. 27 nt length in these siRNAs gives the best performance at silencing and siRNAs with this length called dicer substrate siRNAs, abbreviated as dsiRNA. DsiRNA are better at generating RISC Loading Complex as compared to canonical ones, which are 21 nt long. One of the crucial issue for in vivo application of RNAi machinary stimulation by dsiRNA is fate of the siRNA in variety of body fluids. Because of this issue RNAs can be modified in a way that does not disrupt Dicer association with modified RNA molecule. 2’ – O- methyl modification is a good and not expensive path to jump over problems relate with stability in body fluids. If dosage of modification is extremely high, mission fails in consequence of loss of Dicer related steps in RNAi system.

Lower concentration of dsiRNA is required for satisfactory silencing, compared to canonical siRNAs. Longer time influence and increased specificity provided via the use of dsiRNAs.

So as to decrease off- targetting, dsiRNA clusters enzymmatically produced via the use of Dicer.

In addition to dsiRNA, other alternatives to canonical siRNA occurs like shRNA, dumbell RNA and fork siRNA (Figure 9).

29 nt stemmed and 4 looped shRNAs are better than 19 nt stemmed ones at silencing of target gene. As loop length is also a significant factor however in high concentrations no critical differences in activity efficiency observed between short and long looped shRNAs. Similar to loop length also side of loop (left or right) is not a determinant of silencing activity at high amounts. Although shRNAs protected at one side via its loop, they even degraded fast in body fluids. This problem overcome by Abe and Abe’s colleagues via invention of new type of siRNA that has two loop at both right and left, called RNA dumbell.

Fork siRNAs are generally preferred to knockout mutated or chimerical genes.

By the help of several strategies long dsRNAs also became a RNAi tool for mammalian cells. They are usually opted for multiple target silencing.

Two grups of long interfering RNA occurs, linear (Figure 10) and branched (Figure 11) longs dsRNA, preferentially with several modification to provide nuclease stability. Some experiments validate these multi siRNAs utilize the same pathway with normal siRNAs.

Linear ones bear a gap on one strand. Devoid of gap, they are non- funtional. Branched ones have more variant shapes.

Although noncanonical RNAi inducers costs much for unit, low amounts give satisfactory results.

Cancer
RNAi theraphies offer to stop drug resistence in cancerous cells via switching on/off the relavant signaling paths. Only RNAi based medication is not sufficient in order to defeat cancer, however, combination with other cancer approaches like radiotheraphy and chemotheraphy, cancer may be knockdown.

Escape Strategies of Viruses
Proteins produced because of viral attact leads formation of negative effects on the metabolism of miRNA. FHV (Flock House Virus) produces B2 that inhibits RNAi via preventing Dicer cleavage. B2 activity result in decline in the number of siRNA.

Some miRNAs are capable of contributing to virus replication while some of them may work for prevention of the replication.

Agricultural utilization
Major reason for agricultural damage is shown to be insect pests. Although Bacillus thuringiensis toxin is highly influensive to combat with some of pests, most of the members of insect pests, especially Hempitera, are not affected by the toxin. Because core RNAi mechinary found in all insect pests, RNAi became a strong option as a pestiside. Generally, one method to knock out agricultural pests is not sufficient because of that Integrated Pest Management (IPM) strategies are preferred.

However not all insect groups contain RNAi mechanism which totally limit RNAi inducer applications in RNAi lacking organisms.

It is essential to conserve beneficial insects, honey bee is one of them, from harmful biological factors, like pathoges and parazites, too.

Conclusion
P bodies also includes RNAi activity alongside cytoplasm.

When use of long dsRNA for silencing target gene unsucessfull in mammalian cells, by innate immune system, in non- mammalians these type of RNAs achieves silencing, because of absence of interferon response. Short siRNA are option to bypass innate immune response. With the shortening of normal siRNA, cleavage point of RISC complex alters, too. However, it is observed that, in some cases, even 21 bp siRNA alongside longer ones can initiate interferon mechanism.

Because miRNA effects comparatively more limited than siRNA influence, usage of synthetic miRNA paralel to natural one also more restricted than synthetic siRNAs.

SiRNA theraphies seem to be more influencive among other antisense theraphies in terms of target specifity, longevity, stability in vivo, efficiency at low amounts and spreading of effect to other cells.

It is thought that usage of RNAi instead of transgenic reformation methods to generate genetically modified foods is safer because RNAi do not use the genes of other organisms. Thus organism genetic code remains orginal.

Learning project: what next?
Read about one of these topics and add what you learn to this page:
 * What if inhibitory double stranded RNA could form from hairpins such as those found in tRNA molecules? (hint)
 * What other medical applications have been proposed for RNA interference? (Hints: search here)
 * Add questions and general discussion to the next sections.

Discussions

 * Read RNAi: a novel strategy for the treatment of prion diseases by Qingzhong Kong and Lentivector-mediated RNAi efficiently suppresses prion protein and prolongs survival of scrapie-infected mice by Alexander Pfeifer et al. Discuss the idea that virus-mediated RNA interference can be used to treat neurological diseases.

Mice as a model system
Are short-lived mice a good model system for study of human neurodegenerative diseases?

title: RNA interference


text:
Resistor color codes

 * For example in this example, value of the resistor is ;

 * 1.Digit  = Yellow  = 4
 * 2.Digit  = Orange  = 3
 * Zeros    = Red     = 10^2
 * Tolerance
 * Gold   = ±5%
 * Silver = ±10%
 * No Band = ±20%
 * R = (43 * 10^2) ±10%  =  4300 ± 10% = 3870 ~ 4730 ohms

Practice: Are these correct? Yes.

External Link

 * dot com [/nozomsite/resistor1.htm] - Resistance Color Codes Tutorial With Examples and Calculator.

title: Resistor color codes


text:
File:Resistor color.JPG

Licensing
commons:Category:Resistors

title: File:Resistor color.JPG


text:
File:RNAi pathway.png

Licensing
commons:Category:Molecular biology

title: File:RNAi pathway.png


text:
User:Ramjaw

A 1L in Law School wishing to contribute his knowledge while reviewing. Please contact me through wikiversity as Ramjaw.

Projects

 * Working on the School of Law
 * Specifically, Rules of Civil Procedure and attempting to organize the structure of the school

title: User:Ramjaw