Malaria Control.net

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rebirther
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Malaria Control.net

#1 Post by rebirther » 20.06.2006, 14:28

2006-06-20: Malaria Control
We have enabled account creation again. This time we will disable account creation at approx. 2000 users. We invite new users to Read this first.
Für alle die noch keinen Account haben, jetzt aber los :wink:

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#2 Post by rebirther » 14.01.2007, 18:47

The most noticeable change for users in this version concerns I/O buffering during checkpoint writes. We hope that disk access should be smoother now. We are interested in feedback from those of you who had problems in the past.
Apart from that, several members of the science team were involved in refactoring parts of the science application to accommodate future development.
Mit der neuen v5.45 wurde das Schreiben auf Platte der Checkpoints ein wenig reduziert, Feedbacks sind erwünscht.

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#3 Post by rebirther » 25.09.2007, 18:59

Updates are here

A new science application called "optimizer" will be launched from Monday 17.September onwards, or shortly there after. Watch this thread for news, it will be announced when we start.

At first, it will be run as a test application, meaning that only users who have "run test applications" and "run optimizer application" checked in their account settings (under malariacontrol.net preferences) will get work.

In addition, only windows hosts will get work.

Work units will take from 5 min up to one hour, depending on the model parameters. No checkpointing is done, and progress will not be indicated, so wait at least for an hour before thinking the work unit could be stuck..
Calculation is done by a java program, contained within the standard boinc-"wrapper" application. You need to have java installed.. if not, you will be prompted to do so.
Deadlines: in the testing phase 48h, after that three days.

The name "optimizer" for this application was chosen because the server side components are essentially a "general use" optimization framework to be used by scientists in our group to work on more specific questions. E.g. to fit simpler models for which the "big" malaria model would just not be what you want. The insights from those calculations will help us to improve the main malariacontrol application in the future.

On the science of the project:

To make quantitative predictions of malaria transmission, it is very important to know how long an infection lasts in an infected human. Because the longer it lasts, the more mosquitoes can get infected, the more infected mosquitoes you have, the more humans are being infected etc, etc, etc..
It may at first seem very straightforward to measure this: you just look when somebody gets infected, and then you keep taking blood samples until that person is not infected anymore.
Unfortunately, you only have a chance of about 50% percent to detect an infection, given that it is there. So you already have a problem: you don't know when the infection started, and you don't know exactly when it ended.
In addition: In areas of high malaria transmission people are very often infected with up to ten or more infections simultaneously... so you never know if what you're seeing is still the same infection or a new one..
Recently some work at our institute has used new dna-based methods (which allow distinction of different infections), together with a mathematical approach, to estimate the average duration of an untreated p. falciparum infection.

see Sama etal. 2006
(sorry, only the abstract is freely available to the public)

So far so good, this was an important step forward. The problem that remains is: how are the durations distributed? In other words: do all of the infections last exactly 200 days and then all of them stop? Or does an infection have a constant probability to disappear, which remains constant no matter how old the infection is? Probably none of the two is true, but we need to describe the shape of that distribution of durations somehow, in order to make sensible predictions.

for more on that, see Sama etal.2006b

That's almost where we want to go, except for one thing: the above paper measures the distribution in people living in the US who had never experienced malaria before. They were infected on purpose, to cure their syphilis (the method of choice at that time..) We don't know what the picture looks like in people living in areas of high transmission, with multiple infections at a time and after decades of being constantly infected...

Attempts to find a mathematical solution to this problem did not work out.. the equations become unsolvable. But there is a way out: instead of using equations, we can use individual based simulations, that means we simulate every single infection in a computer program, and see what parameters can best produce the data we have. The big drawback there is, this just takes too long to calculate on a single computer.
That's what we need you guys and girls for, and thanks a lot for making this possible!!

P.S.: Something about the data collection mentioned above, to prevent misunderstandings: There are strict ethical guidelines on how one is allowed to obtain such data. Since most malaria infections in high transmission areas don't cause any symptoms, being infected with malaria doesn't mean you are sick (because of acquired immunity). People who did have symptoms were of course given treatment.
Die Anwendung Estimation of parameters of infection dynamics setzt eine Installation der Javaplattform voraus, ansonsten werden die WUs schon beim Start mit Fehler beendet (Aktivierung nur über die beta apps in den prefs).

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#4 Post by rebirther » 19.10.2007, 21:21

This week we started with some delay a number of new runs with the objective of fitting model parameters of a new type of transmission models. These for the first time allow for heterogeneity in simulated transmission. This will be important to get an accurate description of areas with relatively low malaria transmission intensities.
A consequence of this is that we will need slightly more computing power in the future. We will therefore enable account creation next Monday to allow more users to participate.
In addition, we have optimized the configuration of the scheduler some time ago. It now does a good job at choosing a reliable host (one with a short turnaround time and a high success rate) when resending a result because of an error or timeout. This significantly reduces the number of results that have to be sent a third time, and improves the performance of our optimization algorithm. We can therefore make much better use of the available computing power.

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#5 Post by DoctorNow » 22.06.2016, 12:57

Nach gut 10 Jahren scheint MalariaControl beendet zu sein.
Die Hauptseite/dieser Thread verkündet, daß es in absehbarer Zeit keine Arbeit mehr geben wird - technische Veränderungen machen das verteilte Rechnen für das Projekt mittlerweile unattraktiv.
Das Projekt wird aber online bleiben und es besteht durchaus die Möglichkeit, daß es in (ferner) Zukunft vielleicht wieder auf BOINC zurückgreifen wird.
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#6 Post by DoctorNow » 09.10.2016, 10:09

So, bei BOINCstats wurde das Projekt jetzt stillgelegt, drum hab ich's in der Wiki auch vorgenommen.
Bitte dann auch mal diesen Thread hier zu den Stillgelegten verschieben. ;-)
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