July 2, 2009
05:10 PM
883 views

Sen et al (2007) Learning to Identify Beneficial Partners

Cited by 4 [ATGSATOP]So this is another paper in my attempt to finish the background reading for an invited paper in the AP2PC'07 workshop proceedings. I believe I found this one following a citation trail from Ben-Ami and Shehory (2007) and I think I grabbed it because it had "learning" in the title. Peer to Peer is mentioned in passing, but this paper is really about a multi-agent system where individual agents have learning capabilities. I know the first author from a panel session in AP2PC'05, so that is another connection, but I can't really remember if I had some more complex motivation for printing out this particular paper last October.In principle I am reading this to help illuminate some of the ways that agent research can be of benefit to P2P researchers, but there is a part of me that is just interested in mathematical and algorithmic characterizations of "learning". The paper itself introduces parallels between human and artificial agents trying to make critical choices about interaction partners; and this makes me think of the human interaction analogies in Ian Clarkes Masters thesis on Freenet, my own intuitions about pruning search in my NeuroGrid system, as well as the agent modelling in the paper I co-authored with Ben Tse and Raman Paranjape. We are all humans and we interact with other humans most days, and so I guess it is no surprise that this sort of analogy crops up again and again; however I think there is a pitfall here. Sometimes the analogies breakdown and our intuitions lead us astray - I think this is the case with mobile agents where our human experience of the greater efficiency of human face to face interaction suggests that sending a mobile agent across a network should be more efficient than static agents communicating with each other when in fact it is difficult to predict the relative efficiency of the two methods for mobile agents (Joseph & Kawamura, 2001).The goal of the authors research is to try and discover which learning schemes will sustain mutually beneficial partnerships between agents. Apparently algorithms which achieve equilibria in repeated play have so far been restricted to two-player situations. This paper examines a population of agents that learn through the reinforcement technique of Q-learning (Watkins & Dayan, 1992). The authors restrict their system to one where agents search through repetitive personal interaction; not through referral.In the authors system each agent is of a particular type, and has preferences to interact with agents of other types. Thus the potential reward that agents achieve through interacting with each other is a matrix of agents against types; and the matrix is designed such that some optimal solution of agent partnerships exists where no agent can get a greater reward by switching to interact with other agents. Since the matrix of rewards is unknown to the agents, the Q-learning technique is used to update agents estimates of the rewards of interacting with each other. Q-learning updates estimates through a combination of earlier experiences of reward with the current experience. The extent to which experience influences current estimates is not varied, and the alpha parameter that determines this is not mentioned again in the paper, making a replication difficult. However, in order to vary the agents level of explorative behaviour, i.e. the extent to which agents try out new interactions, the authors adjust the probability with which the agents select a random agent to interact with, rather than the one recommended by the Q-learning estimate. By adjusting this probability over time exploratory behaviour is gradually reduced in what seems like a sort of simulated annealing.No particular justification is given for the particular parameter settings or the approach used, leading me to wonder what the basis for this approach is. Are these techniques similar to others in the literature, or are they based on any empirical observations of real-world phenomena? Nonetheless, initial simulation results in a static environment show that a slow decay of exploratory behaviour is associated with the system taking longer to achieve equilibrium, but also with a higher final average payoff for the agents. This certainly makes intuitive sense.In subsequent simulations dynamic environments are explored where agents die off and are replaced if they fail to achieve a sufficiently high payoff within a certain timeframe. As the environment becomes tougher and agents are killed off more quickly it takes longer and longer for the system to reach a stable equilibrium, although this can be mitigated by reducing the level of exploratory behaviour (see figure d is rate at which exploratory behaviour decays). Again this makes intuitive sense.In further simulations we see that protecting young agents can also help the system achieve equilibrium sooner, which also makes intuitive sense, and makes me think of the use of karma in online communities; or at least the way that new users will be given an initial chunk of reward or karma points. Not sure how strong the parallel is here, but I guess you could model an online community in terms of multi-agents looking for beneficial interactions. New users are entering the community at a certain rate, and not hanging around indefinitely. They will need to have positive interactions within a certain time period before they will effectively remove themselves from the community; which makes me think of that paper that shows the effect of existing social network patterns on incoming users (wasn't it something to do with closed triangular relations) - should re-read that for my thesis project, if I can find it (probably in disCourse somewhere).In a final section the authors experiment with introducing noise and we see that noise can have a similar effect to prolonging exploratory behaviour, i.e. taking longer to get to equilibrium, but perhaps finding a higher optimum. My main concern with all this is the relationship to the real world where systems may spend much of their time away form equilibrium. I see connections to other work that I have done on the evolution of intelligence (where we compared our models with populations of animals in the real world) and online communities, but a lot of the modeling decisions seem to be soewhat arbitrary. It would be nice to know what was motivating them.My references:Joseph S. & Kawamura T. (2001) Why Autonomy Makes the Agent. In Agent Engineering, Eds. Liu, J, Zhong, N, Tang, Y.Y. and Wang P. World, Scientific Publishing.Sandip Sen, Anil Gursel, & Stephane Airiau (2007). Learning to identify beneficial partners Working Notes of the Adaptive and Learning Agents Workshop at AAMAS... Read more »

Sandip Sen, Anil Gursel, & Stephane Airiau. (2007) Learning to identify beneficial partners. Working Notes of the Adaptive and Learning Agents Workshop at AAMAS.

July 2, 2009
03:56 PM
430 views

Sinning saints and other quandaries

by Tom Rees in Epiphenom

Priests and other moral figureheads sometimes go bad. That's inevitable, given that there are so many of them. Still, it makes you wonder if there's something more complex going on. Could it be that moral authority actually contributes to immorality?Back in 2007 there was a study that suggested one way this could happen. People who are convinced of their moral correctness were found to actually be more likely to cheat - because they were more likely to feel that their cheating could be justified.Now a new study suggests that people have a moral 'set point'. Do a good deed, and the temptation is to make up for it by doing something naughty.Other studies have shown the moral-cleansing effect, but this new Northwestern model shows that the cleansing also has to do with restoring an ideal level of moral self-worth. In other words, when people operate above or below a certain level of moral self-worth, they instinctively push back in the opposite direction to reach an internally regulated set point of goodness. "If people feel too moral," Sachdeva said, "they might not have sufficient incentive to engage in moral action because of the costliness of being good." Science DailyBasically, this was a priming study. The participants were asked to write a short essay either on doing a good deed, or a bad one, or neutral. Those who wrote about doing a good deed were least generous in a variety of follow up tests, especially when the good deed they wrote about was their own.The next step, apparently, is to see whether the results hold for other cultures._______________________________________________________________________________________This work by Tom Rees is licensed under a Creative Commons Attribution-Share Alike 2.0 UK: England & Wales License.

... Read more »

Rees, TJ. (2009) Is Personal Insecurity a Cause of Cross-National Differences in the Intensity of Religious Belief?. Journal of Religion and Society. DOI: http://moses.creighton.edu/JRS/2009/2009-17.html

July 2, 2009
02:39 PM
782 views

Bigfoot or Mistaken Identity?

by Evilutionary Biologist in The Evilutionary Biologist

Ecological Niche Modeling is a great tool for conservation biology, phylogeography and evolutionary biology. However, as Jeff Lozier and colleagues point out in a paper in Journal of Biogeography,...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]... Read more »

Lozier, J., Aniello, P., & Hickerson, M. (2009) Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling. Journal of Biogeography. DOI: 10.1111/j.1365-2699.2009.02152.x

July 2, 2009
02:06 PM
1,354 views

Ganlea megacanina: Saki of the Eocene

by zinjanthropus in A Primate of Modern Aspect

Meet the White-faced Saki, Pithecia pithecia. P. pithecia lives in South America, where it scampers about the low canopy eating the seeds of fruit with tough outer shells. To get through those tough outer shells, it has robust, stout canines that are able to pierce the skins and dig out the soft fruit and seeds [...]... Read more »

Beard, K., Marivaux, L., Chaimanee, Y., Jaeger, J., Marandat, B., Tafforeau, P., Soe, A., Tun, S., & Kyaw, A. (2009) A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2009.0836

July 2, 2009
01:04 PM
1,454 views

When are highly-anxious women most anxious? When you least expect it

by Dave Munger in Cognitive Daily

Take a group of 18- and 19-year-old women, college freshmen and sophomores. Then test them to find out who has the most social anxiety: who's most nervous about dealing with other people, particularly in public situations. What would be the most difficult thing you could ask these high-social-anxiety women to do? How about this:

I would like you to prepare and deliver a four-minute talk. This talk will be videotaped and viewed later by several professors and graduate students.... It is extremely important that you do the best job that you can with this talk.... Your talk should be about the most difficult time in your life and how you coped with it.

Now, give them five minutes to prepare, and allow their boyfriends to "help."

That's what a team led by J. Gayle Beck did; their goal was to see how socially anxious women and their romantic partners handled a difficult social situation. They asked women with low social anxiety and their partners to do the same task; 45 women in all participated. Of course, what the researchers were really interested was to see how the couples interacted while they prepared the speeches; in the end none of the women had to give a speech, and they were told their preparation session had been videotaped and would be analyzed for insights into how their relationship worked.

You might think that highly socially anxious women (which I'll abbreviate as HSA) would be more distressed about this than women with low social anxiety (which I'll abbreviate as LSA). You might also think that HSA women who weren't satisfied with their relationships would show more have more negative interactions with their partners than HSA women who were satisfied. And you'd probably speculate that if the boyfriends of HSA women made negative comments or behaved negatively during the preparations, that HSA women would show even more distress.

Beck's team predicted all three of these results, and were surprised to find that none of the predictions were supported by the study. They studied all the videos and rated the women along three dimensions:

Positive: Specific analysis of the problem, statement of feelings, asking for help, positive response to helper

Negative: Demanding help, criticizing, blaming, accusing, rejecting helper, whining, complaining

On Task: Staying focused on the assignment.

The boyfriends were rated on a similar scale. Read the rest of this post... | Read the comments on this post...... Read more »

GAYLEBECK, J., DAVILA, J., FARROW, S., & GRANT, D. (2006) When the heat is on: Romantic partner responses influence distress in socially anxious women. Behaviour Research and Therapy, 44(5), 737-748. DOI: 10.1016/j.brat.2005.05.004

July 2, 2009
11:54 AM
1,236 views

Plants, our saviors from a deep freeze

by Katie Kline in EcoTone

As plants become starved for CO2, rock weathering diminishes. Credit: study coauthor David Beerling

Earth is currently in an ice age. (People, especially climate change naysayers, sometimes forget that.) The growth of the Antarctic ice sheet began about 25 million years ago, and by about 3 million years ago we had a full-blown ice age. [...]... Read more »

Pagani, M., Caldeira, K., Berner, R., & Beerling, D. (2009) The role of terrestrial plants in limiting atmospheric CO2 decline over the past 24 million years. Nature, 460(7251), 85-88. DOI: 10.1038/nature08133

July 2, 2009
11:30 AM
884 views

Take a break from being lazy – your health depends on it!

by Travis Saunders, MSc in Obesity Panacea

Healy, G., Dunstan, D., Salmon, J., Cerin, E., Shaw, J., Zimmet, P., & Owen, N. (2008) Breaks in Sedentary Time: Beneficial associations with metabolic risk. Diabetes Care, 31(4), 661-666. DOI: 10.2337/dc07-2046

Medicine

July 2, 2009
08:00 AM
882 views

Invert science keeps food on table

by Zen Faulkes in NeuroDojo

Simon Leather has a good short article about the problems of working with invertebrates in biology. The problems are not intellectual, but structural. He argues that if you work on invertebrates, you really don’t have much of a chance of getting a job at a major research institution. Some of Leather’s claims are backed by references. But phrases like “it is obvious that” crop up, which are always warning signs for opinions trying to pass themselves off as facts.It contains this short blast:Unless something is done soon to remedy the situation, it will be too late and the only animals that the general public will be able to recognize will be polar bears and tigers.Why we should care, according to Leather, is because of insect pests and their effect on agriculture. Leather misses an opportunity to draw stronger links between invertebrate research and food security. I was surprised not to see honeybee pollination mentioned, for instance. Or the importance of invertebrates as a food source in their own right, either for fish (krill are the base of much of the oceans’ food webs, after all) or for humans (for example, lobster fisheries).As an invertebrate researcher, I share Leather’s concerns. A couple of things may help. First, as I’ve written before, there is always the possibility that vertebrate researchers are going to price themselves out of the market.Second, not every academic or research institution is a major research institution. Not every academic job will need publications in Nature or Science. Given that not every institution has the same resources, those that can’t support full blown research on large vertebrates could become centers of excellence for invertebrate research.ReferenceLeather, S. (2009). Institutional vertebratism threatens UK food security Trends in Ecology & Evolution DOI: 10.1016/j.tree.2009.05.002... Read more »

Leather, S. (2009) Institutional vertebratism threatens UK food security. Trends in Ecology . DOI: 10.1016/j.tree.2009.05.002

July 2, 2009
07:00 AM
1,310 views

Simple, obvious, and wrong answers

by iayork in Mystery Rays from Outer Space

Macrophage phagocytosing mycobacteria

Sometimes the simple, obvious answer is right, and sometimes it’s completely backwards.

Tuberculosis was a terrifying, ubiquitous killer in the 19th century, but is relatively rare today (at least, in developed countries). The reason for the drop in Tb deaths isn’t entirely clear; it started with social factors probably including accidental or deliberate isolation [...]... Read more »

Sadagopal, S., Braunstein, M., Hager, C., Wei, J., Daniel, A., Bochan, M., Crozier, I., Smith, N., Gates, H., Barnett, L.... (2009) Reducing the Activity and Secretion of Microbial Antioxidants Enhances the Immunogenicity of BCG. PLoS ONE, 4(5). DOI: 10.1371/journal.pone.0005531

July 2, 2009
04:25 AM
978 views

A computerised learning tool helps boost study effectiveness

by Christian Jarrett in BPS Research Digest

Much of psychology's efforts over the last few decades have been spent on understanding the nature of memory. Increasingly, though, psychologists are beginning to apply what we've learned about memory, so as to help enhance people's performance. In 2007, the Digest reported on a study that investigated the optimal interval to leave between study periods if you want to remember material long term. Now Claudia Meltzer-Baddeley and Roland Baddeley have tested a related approach to study, known as adaptive training, and found that it too helps boost learning.Adaptive training is a strategic form of study that ensures the learner spends more time focused on material they know less well and less time focused on already mastered material. This means that less familiar material is re-examined more frequently, while better mastered material is gradually left for longer and longer periods. It's possible to employ this kind of system by using stacks of learning cards, whereby correctly answered cards are placed on piles that are re-tested less often. However, there are computerised tools like "SuperMemo" that simplify and enhance this process, allowing the learner to say how confidently they answered each item, which in turn influences the likelihood of that item appearing again.Meltzer-Baddeley and Baddeley tested the ability of 32 undergrads to learn Spanish vocabulary using the SuperMemo software. Crucially, they compared the learning effectiveness of two versions - one employed adaptive training, whilst the other version simply randomised the presentation of the study items. The researchers found that the adaptive training version significantly boosted performance on a vocab test given immediately after training and two weeks' later, compared with performance using the simple randomised presentation of study items.The size of the adaptive training benefit was modest but the researchers said "in real life situations, in which motivated people may come back to material repeatedly across larger periods of times, we would expect much bigger advantages of adaptive spacing." They concluded that adaptive computer based training programmes could prove to be a useful tool "to enhance memory in healthy individuals, as well as people with learning and memory problems."_________________________________Metzler-Baddeley, C., & Baddeley, R. (2009). Does adaptive training work? Applied Cognitive Psychology, 23 (2), 254-266 DOI: 10.1002/acp.1454... Read more »

Metzler-Baddeley, C., & Baddeley, R. (2009) Does adaptive training work?. Applied Cognitive Psychology, 23(2), 254-266. DOI: 10.1002/acp.1454

July 2, 2009
01:34 AM
767 views

Evolution 2009: The Evolution meetings were, indeed, blogged

by Jeremy Yoder in Denim and Tweed

So I've been putting off a final post-mortem on the use of online resources in connection with Evolution 2009, but Nature finally shamed me into it with an article specifically about blogging and microblogging at scientific meetings as part of a special section devoted to science journalism.

The Nature piece captures the concerns that came up when I first broached the subject of trying to increase the meetings' online profile, especially the question of unwanted publicity: scientific meetings often serve as forums for presentation of work in progress -- ideally, you're hoping there will be people in the audience with interesting ideas for how to proceed -- and presenters don't necessarily want unfinished work broadcast all over the globe. Most obviously, there's the (I would say slightly paranoid) fear of getting "scooped" because a rival reads about your work on a blog and kicks into high gear to publish first.

It's not clear to me, however, that blogging really increases this risk; the people most interested in a given scientist's work, and therefore most likely to work on similar things and potentially scoop her, are probably already in the live audience. And, furthermore, as the Nature piece points out, online coverage of work in progress could actually serve to establish priority in case of a real dispute. In any event, scientific societies are already adapting:Conference organizers contacted by Nature had a wide range of policies on social networking. Many societies have banned digital photography in talks and poster sessions and some consider bloggers to be members of the media and subject them to certain reporting restrictions. ...

Journals are also pondering how best to handle social networking at meetings. Nature generally supports social media tools, says Philip Campbell, Nature's editor-in-chief. And as long as it's not a deliberate attempt to hype a new finding, he says that researchers should feel free to talk to colleagues who blog or twitter.Blogging is increasingly recognized as a great way to communicate science to the public, and it seems likely we'll see it become well-integrated into scientific meetings. Online coverage of Evolution 2009 was, I'd say, a good start. The page I set up to aggregate posts about the meetings drew 15 posts from 6 blogs, with most posting (12/16) occuring during the meetings. I'm still adding to that page as followup posts appear on participating blogs. If I had to organize that page again, I think I'd look for a better -- maybe even automated -- way to locate and link to posts. The volume wasn't so much that I couldn't handle it by monitoring a few RSS feeds myself; but I assume that blog coverage will increase in future years.

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The FriendFeed I set up for the meetings drew less traffic than I'd hoped; 15 subscribers, and 74 contributions from various sources. I've broken down FF posts by topic in the graph on the right. In general, people used the FriendFeed about as I'd have predicted. They posted reactions to talks;heard Mike Levine, Matt Rockman and Joe Thornton's symposia at #E09... just brillianttheir own status during the meeting;back from birding, time for some talks #E09useful information;visit the Systematic Biology exhibit for an amazing (free) Timetree of Life poster #E09and, yes, they complained about the catering.@mlabrum coffee seems to be a prohibited substance in Moscow. #E09Fortunately conference coordinator Darrell Keim kept an eye on the feed, and was able to respond in some cases.

What we didn't see much was back-and-forth discussion, as described at the 2008 meeting of the International Society for Computational Biology. A lot of this, I assume, is down to (1) the fact that computational biologists are more techy than your average evolutionary biologist, which contributed to (2) comparatively low subscription to the FriendFeed. I set the dedicated feed up just before the meeting, too, so there may not have been a lot of awareness that it was available until later. Traffic to the meeting website peaked the day before the meetings started (at 658 unique hits), and it takes a good lead-in to draw participation to something new like this. The official Twitter feed attracted 93 subscribers, and I linked to that from the main page very early on.

This meeting also saw the first webcast of any meeting activities -- specifically, and appropriately, Eugenie Scott's lecture on communicating science to the public. It wasn't live, but it's a start. Next year, it'd be great to see all the "flagship" lectures -- the societies' presidential addresses, maybe some of the symposia given by societal award recipients -- put online.

This was all, as I have now said repeatedly, a good start. No previous Evolution meetings (to my knowledge) have aggregated related blog posts, or provided a near-real-time forum for reactions and discussion, or posted video from a major public lecture. I expect that the value of these resources will only increase as more people use them -- we'll have to see how things work out next year, in Portland, Oregon.

References

Batts, S., Anthis, N., & Smith, T. (2008). Advancing science through conversations: Bridging the gap between blogs and the academy PLoS Biology, 6 (9) DOI: 10.1371/journal.pbio.0060240

Saunders, N., Beltrão, P., Jensen, L., Jurczak, D., Krause, R., Kuhn, M., & Wu, S. (2009). Microblogging the ISMB: A new approach to conference reporting PLoS Computational Biology, 5 (1) DOI: 10.1371/journal.pcbi.1000263... Read more »

Batts, S., Anthis, N., & Smith, T. (2008) Advancing science through conversations: Bridging the gap between blogs and the academy. PLoS Biology, 6(9). DOI: 10.1371/journal.pbio.0060240

Saunders, N., Beltrão, P., Jensen, L., Jurczak, D., Krause, R., Kuhn, M., & Wu, S. (2009) Microblogging the ISMB: A new approach to conference reporting. PLoS Computational Biology, 5(1). DOI: 10.1371/journal.pcbi.1000263

July 2, 2009
12:46 AM
685 views

Sydney Brenner on C. elegans

by GrumpyBob in Flies and Bikes

The latest issue of Genetics to flop onto my desk has a rather nice article by Sydney Brenner entitled "In the Beginning Was the Worm...". This brief article (in the regularly excellent Perspectives section) presents an account of the origins of Caenorhabditis elegans research, by the beast's main man, research which ultimately earned him Nobel Prize fameRead More...... Read more »

Brenner, S. (2009) In the Beginning Was the Worm .. Genetics, 182(2), 413-415. DOI: 10.1534/genetics.109.104976

July 1, 2009
11:03 PM
665 views

Looking for the Mathematical Brain

by Michael in dlPFC

An interesting and largely unanswered question concern the acquisition of our ability to understand and perform mathematics. We appear to innately possess an concrete grasp of only a handful of small values, and yet we frequently engage in transactions for quantities that reach into the hundreds or thousands.

Our ability to perform these computations no doubt [...]... Read more »

Knops, A., Thirion, B., Hubbard, E., Michel, V., & Dehaene, S. (2009) Recruitment of an Area Involved in Eye Movements During Mental Arithmetic. Science, 324(5934), 1583-1585. DOI: 10.1126/science.1171599

July 1, 2009
08:22 PM
852 views

Subtleties of Calorie Restriction and Evolution

by Reason in Fight Aging!

My attention was drawn today to a recent open access paper that theorizes on how evolution came to produce the calorie restriction response. Given that calorie restriction notably improves health and longevity, why isn't this beneficial metabolic state switched on all the time? Stresses like dietary restriction or various toxins increase lifespan in taxa as diverse as yeast, Caenorhabditis elegans, Drosophila and rats, by triggering physiological responses that also tend to delay reproduction. Food odors can reverse the effects of dietary restriction, showing that key mechanisms respond to information, not just resources. Such environmental cues can predict population trends, not just individual prospects for survival and reproduction. When population size is increasing, each offspring produced earlier makes a larger proportional contribution to the gene pool, but the reverse is true when population size is declining. ... We conclude that the beneficial effects of stress on longevity (hormesis) in diverse taxa are a side-effect of delaying reproduction in response to environmental cues that population size is likely to decrease. The reversal by food odors of the effects of dietary restriction can be explained as a response to information that population size is less likely to decrease, reducing the chance that delaying...... Read more »

Ratcliff, W., Hawthorne, P., Travisano, M., & Denison, R. (2009) When Stress Predicts a Shrinking Gene Pool, Trading Early Reproduction for Longevity Can Increase Fitness, Even with Lower Fecundity. PLoS ONE, 4(6). DOI: 10.1371/journal.pone.0006055

July 1, 2009
07:45 PM
1,210 views

Mapping the Sasquatch

by jebyrnes in I'm a chordata, urochordata!

I love modeling! I love modeling! Modeling will solve everything!

Let’s model the spatial distribution of Bigfoot!

WAIT, WHAT?!

Figure 1 from the paper. Foots denote sighting of Sasquatch footprints. Circles for just visual/auditory sightings. I ask, how does one know what Bigfoot sounds like?

Yes, it sounds silly, but in the current issue [...]... Read more »

Lozier, J., Aniello, P., & Hickerson, M. (2009) Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling. Journal of Biogeography. DOI: 10.1111/j.1365-2699.2009.02152.x

July 1, 2009
04:31 PM
1,082 views

ABI SOLiD Joins the WGS Party

by Daniel Koboldt in Massgenomics

At last published in early access at Genome Research is the whole-genome sequencing of a Yoruban male on ABI SOLiD technology. A year ago, this might have merited a Nature or Science publication. That window seems to have closed for whole-genome sequencing of a single, undiseased individual. By my count, this is the sixth published [...]... Read more »

McKernan, K., Peckham, H., Costa, G., McLaughlin, S., Tsung, E., Fu, Y., Clouser, C., Dunkan, C., Ichikawa, J., Lee, C.... (2009) Sequence and structural variation in a human genome uncovered by short-read, massively parallel ligation sequencing using two base encoding. Genome Research. DOI: 10.1101/gr.091868.109

July 1, 2009
03:07 PM
643 views

Happy New (Medical) Year!

by PalMD in White Coat Underground

The medical education calendar begins and ends on the first of July each year, and in the hospital, that means a brand spanking new crop of young doctors. While this may sound a bit scary, the facts are a bit subtle (and not terrifying). Some of the questions regarding the so-called July Phenomenon are:

Are hospitals more dangerous in July?

Is care more expensive in July?

Are hospital stays longer in July?

The data show that there does not appear to be an increase in poor outcomes in July vs. other months, but in some fields hospital stays may be longer and care may be more expensive due to increased utilization of tests.

Most of the data that support a July phenomenon in hospitals aren't all that strong, indicating that it's unlikely hospital care is significantly different in July vs. other months.

July is fun though. New doctors are excited to learn and to work, and soak it up like sponges, except in crisp white coats.

References

Rich, Eugene C.; Hillson, Steven D.; Dowd, Bryan; Morris, Nora. Specialty Differences in the 'July Phenomenon' for Twin Cities Teaching Hospitals. Medical Care. 31(1):73-83, January 1993.

Barry, W., & Rosenthal, G. (2003). Is There a July Phenomenon?. The Effect of July Admission on Intensive Care Mortality and LOS in Teaching Hospitals Journal of General Internal Medicine, 18 (8), 639-645 DOI: 10.1046/j.1525-1497.2003.20605.x

Myles, Thomas D. Is There an Obstetric July Phenomenon? Obstetrics & Gynecology . 102(5, Part 1):1080-1084, November 2003.

Ford, A., Bateman, B., Simpson, L., & Ratan, R. (2007). Nationwide data confirms absence of 'July phenomenon' in obstetrics: it's safe to deliver in July Journal of Perinatology, 27 (2), 73-76 DOI: 10.1038/sj.jp.7211635

Read the comments on this post...... Read more »

Barry, W., & Rosenthal, G. (2003) Is There a July Phenomenon?. The Effect of July Admission on Intensive Care Mortality and LOS in Teaching Hospitals. Journal of General Internal Medicine, 18(8), 639-645. DOI: 10.1046/j.1525-1497.2003.20605.x

Ford, A., Bateman, B., Simpson, L., & Ratan, R. (2007) Nationwide data confirms absence of ‘July phenomenon’ in obstetrics: it's safe to deliver in July. Journal of Perinatology, 27(2), 73-76. DOI: 10.1038/sj.jp.7211635

Health

July 1, 2009
02:20 PM
900 views

Growing old and collecting cellular junk

by Paul in Green Light Go

I just finished an entry for the SOA timeline on the 1970s discovery that nematodes collect inactive enzymes and molecules as they grow older. The main idea being that the body is unable to clear out the junk inside cells and that the energy cost of carrying this junk leads to senescence, or aging.

The theory [...]... Read more »

Harriet Gershon, & David Gershon. (1970) Detection of Inactive Enzyme Molecules in Ageing Organisms. Nature. DOI: http://sageke.sciencemag.org/cgi/content/abstract/sageke;2002/37/cp16

Murphy, C., McCarroll, S., Bargmann, C., Fraser, A., Kamath, R., Ahringer, J., Li, H., & Kenyon, C. (2003) Genes that act downstream of DAF-16 to influence the lifespan of Caenorhabditis elegans. Nature, 424(6946), 277-283. DOI: 10.1038/nature01789

July 1, 2009
11:52 AM
947 views

Cosmic Cluedo

by Niall in we are all in the gutter

It was Omega Centauri in the galactic disk with the gravitationally induced star formation. That’s the conclusion of a new paper by some Brazilian astronomers.... Read more »

Salerno, G., Bica, E., Bonatto, C., & Rodrigues, I. (2009) On the possible generation of the young massive open clusters Stephenson 2 and BDSB 122 by ω Centauri. Astronomy and Astrophysics, 498(2), 419-423. DOI: 10.1051/0004-6361/200911737

Astronomy

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