When considering language abilities in non-human animals, it pays to keep in mind that spoken words are not the only path to sophisticated communication. For example, while great apes like chimpanzees and orangutans may be limited in their ability to … Continue reading →... Read more »
Many articles, including my own research show, that companies tend to focus largely on risk mitigation measures concerning the supply side. Only little is done to include demand side risks or demand side measures into the mitigation of supply chain risks. The study “Pricing During Disruptions: A Cause of the Reverse Bullwhip Effect” focusses on optimal pricing measures during a disruption. And so it helps to close the gap a little bit.... Read more »
Rong, Y., Shen, Z.-J. M., & Snyder, L V. (2011) Pricing During Disruptions: A Cause of the Reverse Bullwhip Effect. SSRN. info:/
Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
E. F. Schumacher (1911-1977) British Economist
Vaccines represent one of the most cost effective methods around to prevent loss of life and disease in a whole range of animals, including the human population. Over the last 200 years or so, we've become pretty adept at producing them and so the science of vaccinology - or how to generate these complex pharmaceuticals - has led to the eradication (and near eradication) of many viral pathogens.
This is one network in your immune response following influenza vaccination (Kokke et al 2011) as id'd through systems biology approaches. Knowledge of key mediators in these pathways may allow for the rational design of new vaccines - but is it worth it?
But, it hasn't succeeded for a number of currently killer viruses (respiratory synycitial virus and HIV to name but two) and we have begun to think that maybe the method of 'isolate, attenuate, vaccinate' or the synthesis of single virus antigen molecules isn't gonna cut it anymore. So what are we going to do?
We are wanting to rationally generate vaccines - taking a wild-type, disease-causing isolate and through some genetic engineering, make it sufficiently weak so as to generate an effective immune response in patients while not causing disease. Yet, this is harder than it looks and so some researchers are now turning to systems biology to offer a glimpse into how some of our most successful vaccines function so as we can reconstruct these processes for the numbers of viral pathogens we are yet to protect against.
*I have explored how we may attempt to do this from the viruses perspective (mumps virus versus vaccine, here), more precisely: how come the vaccine strain is less deadly than the 'wild' strains. Both are valid approaches and probably just as difficult to carry out as each other.*
Systems biology affords us a chance to more fully understand the complexity of living systems. Through the collection of reams of data (DNA sequences, gene expression changes, protein levels - and other 'omics' technologies) we are now able to adequately model what is going on in the organism/cell through now more common bioinformatic and statistical analyses. As in the quote I used above, it is not about making the study of life more complex, it is really about realizing this fact and doing something to understand it better under a broader way of thinking. This allows us to 'see' changes and functional differences that we would never have observed had we gone about such an experiment using our a priori knowledge and this global, holistic view may just be the savior that vaccinology needs now.
Example of the complex data collected during a typical 'systems' experiment - what does it all mean, and how can we find something important and worthwhile to study?
I am aware of a number of papers that are currently using this process as a primer to develop improved vaccine products (see here, here and review here of virus vaccine examples). These guys - for example: Bali Pulandran of the Emory Vaccine Centre in Atlanta, USA - are interested in comparing the immune response (humoral response, innate immunity and gene expression changes) of human subjects administered with vaccines. The response to the yellow fever virus vaccine as well as two types of influenza vaccines have been approached and through complex bioinformatic modelling they were able to pull out some significant correlates of immune response - this they hope will aid in the future testing of novel vaccines and facilitate a rational take on vaccine generation by identifying a gene(s)/protein with a functional role in the immune response. This they have begun to do in some of ther papers above - it is nice to see this kind of work being used as a basis for experimental biology.
These types of studies hail a new way of thinking about viruses, vaccines and the immune response to them; if only we can realize the power in taking a step back and looking at the diversity in each. And this type of work could be applied to any number of mechanisms such as vaccine safety or applying it to different tissues during an infection.
Saying that - this stuff isn't particularly easy, cheap or quick as you might think. But as each study generates so much data, might it not take but a few such investigations to lead us on the way of rationally attenuated and protective vaccines? So, should vaccinology embrace systems biology? I think if you have the abilities to do such a study - which from a pharma perspective definitely yes, do it as the more information we have at our disposal the better position we are in. We await further results from these groups to compare how well systems thinking goes up against human ingenuity, that has worked well in the past.
Nakaya HI, Wrammert J, Lee EK, Racioppi L, Marie-Kunze S, Haining WN, Means AR, Kasturi SP, Khan N, Li GM, McCausland M, Kanchan V, Kokko KE, Li S, Elbein R, Mehta AK, Aderem A, Subbarao K, Ahmed R, & Pulendran B (2011). Systems biology of vaccination for seasonal influenza in humans. Nature immunology, 12 (8), 786-95 PMID: 21743478... Read more »
Nakaya HI, Wrammert J, Lee EK, Racioppi L, Marie-Kunze S, Haining WN, Means AR, Kasturi SP, Khan N, Li GM.... (2011) Systems biology of vaccination for seasonal influenza in humans. Nature immunology, 12(8), 786-95. PMID: 21743478
by Persuasion Strategies in Persuasive Litigator
By Dr. Ken Broda-Bahm - With Standard & Poor's recent decision to deny the U.S. a AAA credit rating, many Americans are feeling a little downgraded about now. For most of us, I can hope, that is a temporary feeling. But for others, especially in these economic times, it is a more constant aspect of their lives. These Americans, including increasingly those who show up for jury duty, are what the researchers call "status inconsistent." They may be higher in social prestige than in economic means (like teachers), or they may be highly educated, while holding a lower-level position. Indeed,...
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Michael W. Kraus, Paul K. Piff, Dacher Keltner. (2011) Social Class as Culture: The Convergence of Resources and Rank in the Social Realm . Current Directions in Psychological Science, 20(4). info:/
Lenski, G. (1967) Status Inconsistency and the Vote: A Four Nation Test. American Sociological Review, 32(2), 298. DOI: 10.2307/2091819
Since I'm gearing up for a new semester (finishing up syllabi, packing for a move, etc.), I haven't had as much time as I'd like to blog about the interesting reports and publications that have come out recently on the topic of Roman-era skeletons. So here's a carnival or round-up of links from the past few weeks, things I've wanted to talk about but haven't had the time to craft full posts about.
Roman Child Skeleton from Durnovaria
August 10 - Today's news brought a brief story about the discovery of a skeleton of a Roman child from what used to be Durnovaria (modern-day Dorchester, England). There's no osteological information in the report, but there is a nice little history of Durnovaria and this photo of the skeleton, which was found within the settlement (unclear if it was in a house). It's not unusual to find children buried outside of cemeteries - within houses, near walls, etc.
August 8 - On Monday, the BBC gave a bit more coverage to the discovery of nearly 100 infant skeletons in a Roman-era villa in Britain. Jill Eyers, who rediscovered the skeletons in a storeroom, put forth the idea last year that these infants were killed on purpose and that the villa was in use as a brothel. [Original BBC report here, bit of video here.] Dr. Eyers remains convinced of her theory, but scholars in both the classical and anthropological blogospheres are questioning that. Most notable are the posts by archaeologist Rosemary Joyce, who wrote a critique of the theory last year and wrote an updated post yesterday continuing to cast doubt on the whole brothel idea. Dr. Joyce's posts are well worth a read, as she delves into the historical and archaeological evidence of Roman brothels to bring a counter-point to the discussion of this interesting discovery.
August 8 - The American Journal of Physical Anthropology published an interesting paper on Monday by Becky Redfern and Sharon DeWitt (2011) on the effect of status on mortality risk in Roman-era Dorset, England. The authors looked at nearly 300 individuals dating to the 1st to 5th centuries AD and assigned them a status level based on burial type. Using models of mortality, they found that indeed higher-status individuals had lower mortality risk. This was especially true for children and for people who were buried (and presumably lived in) an urban environment. Interestingly, male mortality risk was higher than female mortality risk (I presume owing to warfare and other job hazards). Redfern and DeWitt conclude that, "...the cultural buffering afforded by being of high status enabled people to more effectively deal with urban environments and migration, with lower-status individuals having greater risk because of their forms of employment and living conditions." We can, of course, assume that individuals with higher status had better diets and overall health, and therefore lower mortality risk. But it's great to see researchers actually test that hypothesis. It's also interesting to see that urban denizens had lower risk of mortality; in many ancient societies, urbanism meant dramatic changes to health and wellbeing, but I've also been finding with my Romans that those who lived in or near the city were generally healthier than those from the suburbs and countryside.
Mummies arranged by age, sex, and occupation.
(credit: Panzer et al. 2010, Fig. 2)
Not Roman and not recent news, but still neat: last summer, S. Panzer and colleagues published a study of late 19th/early 20th century mummies from the Capuchin Catacombs in Palermo, Sicily. The pictures in the article are astounding: the mummies are excellently preserved, and the radiographs show a variety of minor pathological conditions (e.g., healed fractures) in some of the mummies. The authors were able to learn a lot about embalming techniques and about the health of the people who were given this treatment after death.
Interactive Teaching ToolsAnd finally, this link has been sitting in my bookmarks for a while. I discovered the BBC's online video game Dig It Up: Romans through Katy Meyers' blog post (July 14, at Play the Past). It's cute, fun, and educational. Katy writes that, "not only does the game allow payers to see the different stages of archaeology, but it is all done in a cultural resource management with the threat of construction setting time limits." Unfortunately, I didn't find a skeleton when I played... just a lamp and an amphora. But the game shows that archaeologists need sampling strategies, that we don't always find every piece of an artifact, and that we don't always find anything of interest (ah, memories of Spam cans from my days excavating at Monticello). Go play it now! You know you need a break from work.
Panzer S, Zink AR, & Piombino-Mascali D (2010). Scenes from the past: radiologic evidence of anthropogenic mummification in the Capuchin Catacombs of Palermo, Sicily. Radiographics 30 (4), 1123-32. PMID: 20631372.
Redfern RC, & Dewitte SN (2011). Status and health in Roman Dorset: The effect of status on risk of mortality in post-conquest populations. American Journal of Physical Anthropology PMID: 21826637.... Read more »
Redfern RC, & Dewitte SN. (2011) Status and health in Roman Dorset: The effect of status on risk of mortality in post-conquest populations. American Journal of Physical Anthropology. PMID: 21826637
When the first single-celled organisms left behind their loner ways and began existing as blobs of cells, it was a big step for life on this planet. Organisms could now grow orders of magnitude larger than each other. They could organize their cells into different types that performed different functions. Instead of drifting around with the other specks, multicellular organisms could grow, swim, crawl, fly, and evolve into everything else on Earth today.It's nearly impossible to know how organisms first made the leap into multicellularity. But in an effort to look back in time, researchers in Japan bred collections of yeast cells that competed with each other for food. They found that the innovation of living as a group of cells would have given the first many-celled organisms a clear advantage--and that it may have been spurred by nothing more than sloppy wall building.Yeast is a single-celled fungus, but in the wild it sometimes grows in clumps. This happens when a yeast cell clones itself, budding an identical "daughter cell," but fails to pinch the clone entirely free. These cells continue to reproduce, forming clumps. The researchers wondered if this incomplete separation of single-celled clones could have fostered the rise of multicellularity.To find out, they first looked at individual yeast cells growing in an environment where their only food was sucrose, a sugar they have to break down before ingesting. To do this, the yeast secrete an enzyme called invertase that splits sucrose into its components, fructose and glucose, which the cell can then absorb. (One advantage of being a complex, multicellular animal is that we don't have to digest our food outside our bodies.) When the yeast cells were all alone, they struggled to survive in the all-sucrose environment. But when other yeast cells were nearby, they all benefited by absorbing the leftover sugars that escaped their neighbors.Knowing that external digestion works better with friends around, the researchers hypothesized that clumps of yeast should be able to thrive where individual yeast cells can't. They genetically engineered yeast with a gene that encouraged clumping, rather than separation. As predicted, these clumpy yeast were able to grow in environments with a low concentration of food, where single yeast cells couldn't survive.It takes work for yeast cells to make and secrete invertase, though. Cells that are unable to make invertase are called "cheaters" because they can sit back and enjoy (or absorb, at least) the fruits of their neighbors' external digestion. If they're all alone, these cheaters won't find enough food. But when they're around enough other single cells, the cheaters will outcompete the hard-working invertase producers.To find out whether multicellularity would help yeast defend themselves against cheaters, the researchers arranged competitions between cheater yeast cells and non-cheaters, either alone or in clumps. At low food concentrations, the clumpy cells easily outcompeted the individual cells, ending up with higher numbers in their population. When cheaters were thrown into the mix, clumpy cells retained their advantage. All around, clumping was a better strategy.The authors may have modeled the beginning of multicellularity--or one beginning, since the trait evolved multiple times. They showed that the need to digest your food externally is enough to give groups of cells an edge over single cells, and that the strategy of keeping your clones all in one place is enough to seize that advantage. When the first mutant cells failed to fully separate from each other, and found that their little family was now growing faster than the individual cells around them, it could have been the start of something big. (That is, visible without a microscope.)They may be mere microscopic fungi, but a community of yeast cells has similarities to a community of animals, or even a city. Organisms live in groups when doing so helps them to get food, fend off predators, and pass on their genes. Even when our communities resemble disorganized, unsightly blobs, they're what keep our species alive.H. Koschwanez, J., R. Foster, K., & W. Murray, A. (2011). Sucrose Utilization in Budding Yeast as a Model for the Origin of Undifferentiated Multicellularity PLoS Biology, 9 (8) DOI: 10.1371/journal.pbio.1001122... Read more »
H. Koschwanez, J., R. Foster, K., & W. Murray, A. (2011) Sucrose Utilization in Budding Yeast as a Model for the Origin of Undifferentiated Multicellularity. PLoS Biology, 9(8). DOI: 10.1371/journal.pbio.1001122
The Honshu tsunami of March 11th (the one that caused the Fukushima disaster) caused the otherwise stable Sulzberger Ice Shelf to calve giant hunks of ice. Climate scientists call this "teleconnection." I call it a big whopping bunch of whack knocking off a gigunda chunka stuff. Either way, this is important and interesting. Read the rest of this post... | Read the comments on this post...... Read more »
Brunt, Kelly M., Okal, Emile A., & MacAyeal, Douglas. (2011) Antarctic ice-shelf calving triggered by the Honshu (Japan) earthquake and tsunami, March 2011 . Journal of Geology, 57(205), 785-788. info:/
Edward Jenner's smallpox vaccination
Bring to mind the now famous 'first scientific exploration of vaccination', when, in the late 1700's, Edward Jenner - an English physician - first came up with the idea of using a non-pathogenic cowpox virus to vaccinate people against its deadly relative, smallpox (variola virus).
Well, this virus and others like it, such as vaccinia virus (and its own viral derivatives, like the highly attenuated modified vaccinia virus Ankara) have been used worldwide to protect human populations from contracting smallpox (See dryvax and it's recombinant clone ACAM2000), which resulted in the eradication of variola virus during the second half of last century. These viruses are thought to all trace there ancestry back to cowpox isolates from around Jenner's time in the late 1700's, yet we don't really know for 100% where they originated.
Despite its renowned success, showing society the power of vaccination, the origins of cowpox have so far remained elusive. The story goes that Jenner's original cowpox isolate, through generations and generations has somehow become what we know of as vaccinia virus but how is anyone's guess. Maybe recombination with other poxviruses out there or maybe it is the last living representative of an extinct virus is the reason why.
What human cowpox looks like
Now, an international team of researchers (see paper here) has shed light on it's origins by sequencing and studying whole genomes - contrary to the single-gene-centric studies in the past - of multiple currently circulating isolates of cowpox from around the world in order to uncover the secrets of poxvirus evolution in general.
Viruses are a haven of genetic diversity - even DNA viruses, which have been largely ignored on that front in favor of their more mutation-prone RNA cousins; this fact is no more apparent than in the case of poxviruses. These viruses, including smallpox and the re-emerging human pathogen monkeypox represent an immense amount of genotypic and phenotypic variation, which is in itself medically and evolutionarily important. Just think of the devastation that smallpox caused to the human population and have a look at what monkeypox has been up to.
False-color electron micrograph of vaccinia virus particle
This group compared the DNA of the cowpox strains to other closely related pox viruses, such as: smallpox itself, monkeypox, camelpox and tatera pox (viruses which themselves have a difficult to trace past) as well as current vaccine vaccinia strains. They thus generated large phylogenetic trees based on the compared sequence and then mapped these onto a map of Europe to see if they could uncover some geographical pattern of cowpox evolution.
This analysis found an as yet unappreciated diversity hidden under what we called 'cowpox viruses' through identification of a number of well-defined monophyletic groups that should in their own rights be designated separate species. Interestingly, it also appears that our vaccine strain has jumped species to horses and buffalo as viruses isolated from these species have close relatives in vaccinia-like strains.
Cowpox viruses were found to cluster in two major groups - cowpox like and vaccinia virus like suggesting that our smallpox 'vaccinia' vaccine potentially originated as a cowpox virus (as we thought) yet it was endemic to mainland Europe, something that goes against the tale of Jenner's isolation of cowpox from the UK.
The authors suggest that further sampling of more isolates from within the UK and across Europe may clear up any taxonomic uncertainties here. What this work does highlight is the oft under appreciated diversity of large DNA viruses, especially the medically important pox viruses and the difficulties of doing evolutionary analysis on viruses which such large genomes who like to recombine with each other.
Carroll, D., Emerson, G., Li, Y., Sammons, S., Olson, V., Frace, M., Nakazawa, Y., Czerny, C., Tryland, M., Kolodziejek, J., Nowotny, N., Olsen-Rasmussen, M., Khristova, M., Govil, D., Karem, K., Damon, I., & Meyer, H. (2011). Chasing Jenner's Vaccine: Revisiting Cowpox Virus Classification PLoS ONE, 6 (8) DOI: 10.1371/journal.pone.0023086... Read more »
Carroll, D., Emerson, G., Li, Y., Sammons, S., Olson, V., Frace, M., Nakazawa, Y., Czerny, C., Tryland, M., Kolodziejek, J.... (2011) Chasing Jenner's Vaccine: Revisiting Cowpox Virus Classification. PLoS ONE, 6(8). DOI: 10.1371/journal.pone.0023086
Age-related cognitive decline is, to a certain extent, unavoidable. Nevertheless, the rate of cognitive decline varies greatly between individuals. This variance may include environmental and genetic determinants.Vascular disease is a risk factor for accelerated brain aging, Alzheimer's disease and other neurodegenerative disorders. Vascular disease is therefore an appropriate target to explore strategies for secondary prevention--preventing (or reducing) risk of cognitive decline in those with a risk factor for this decline.French scientist Marie-Noel Vercambre, along with colleagues from Harvard University have recently examined the role of exercise and cognitive decline in women with vascular disease. Women participating in this study were 40 or older with evidence of vascular disease, or risk for vascular disease, by meeting one of the following criteria:History of stroke, transient cerebral ischemia attack, heart attack, angina, angioplasty, coronary artery bypass graft OR peripheral artery surgeryThree or more risk factors for vascular disease (diabetes mellitus, hypertension, hyperlipidemia, obesity and family history of early heart disease)The women in the study were followed prospectively with monitoring of cognitive function. Cognitive function testing included tests of memory, mental status and category fluency were completed at baseline and during followup period over an average of about 5 years.The primary outcome measure in this study was rate of cognitive decline. Subjects were grouped into those with the lowest and highest levels of physical activities including walking and then examined for correlation with physical activity levels.The women at the end of the study were in their early 70s. Women with high levels of walking (approximately) 30 minutes of brisk walking daily) had significantly lower rates cognitive decline. Women with daily walking habits performed at a cognitive level equivalent to non-walkers who were five to seven years younger.This study looked for correlation and was not designed to prove walking is the cause of reduced rate of cognitive decline. Nevertheless, this research promotes further clinical trial research of aerobic exercise in women with vascular disease. It will be important to include cognitive health as an important outcome measure in this type of research.Photo of Juno Beach sunrise with filter from the author's collection. Original unfiltered photo can be found here.Vercambre, M., Grodstein, F., Manson, J., Stampfer, M., & Kang, J. (2011). Physical Activity and Cognition in Women With Vascular Conditions Archives of Internal Medicine, 171 (14), 1244-1250 DOI: 10.1001/archinternmed.2011.282... Read more »
Vercambre, M., Grodstein, F., Manson, J., Stampfer, M., & Kang, J. (2011) Physical Activity and Cognition in Women With Vascular Conditions. Archives of Internal Medicine, 171(14), 1244-1250. DOI: 10.1001/archinternmed.2011.282
Here at OpenHelix we think a lot about the differences between nominally similar software that will accomplish some given task. For example, in our workshops we are often asked about the differences between genome browsers. Although UCSC sponsors our workshops and training materials on their browser, we know they aren’t the only genome browser out [...]... Read more »
Lacroix, T., Loux, V., Gendrault, A., Gibrat, J., & Chiapello, H. (2011) CompaGB: An open framework for genome browsers comparison. BMC Research Notes, 4(1), 133. DOI: 10.1186/1756-0500-4-133
We have known for a long time that secondhand smoke can have a serious impact on the physical health of children. Asthma, sudden infant death syndrome, respiratory tract infections, dental decay, and middle ear infections are just a few of the illnesses that children exposed to secondhand smoke develop at significant rates. In case parents [...]... Read more »
Bandiera FC, Richardson AK, Lee DJ, He JP, & Merikangas KR. (2011) Secondhand smoke exposure and mental health among children and adolescents. Archives of pediatrics , 165(4), 332-8. PMID: 21464381
Hamer M, Ford T, Stamatakis E, Dockray S, & Batty GD. (2011) Objectively measured secondhand smoke exposure and mental health in children: evidence from the Scottish Health Survey. Archives of pediatrics , 165(4), 326-31. PMID: 21135317
Smallholder farmers overwhelmingly save their own seed, maybe getting a bit extra from relatives, friends, neighbours and, very occasionally, further afield. If climate change is going to affect growing conditions — and it is — will the so-called informal sector be able to supply them with material that can thrive in the new conditions? A [...]... Read more »
Bellon, M., Hodson, D., & Hellin, J. (2011) Assessing the vulnerability of traditional maize seed systems in Mexico to climate change. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1103373108
Being a parent of a child with a developmental disorder has to be one of the most stressful and challenging of all human experiences. Looking after someone afflicted with such a disorder is difficult not only because of the direct symptoms of the disorder but also because of the indirect effects that come around and [...]... Read more »
Baker JK, Smith LE, Greenberg JS, Seltzer MM, & Taylor JL. (2011) Change in maternal criticism and behavior problems in adolescents and adults with autism across a 7-year period. Journal of abnormal psychology, 120(2), 465-75. PMID: 21319925
by Rita Handrich in The Jury Room
As trial consultants based in Austin, Texas (one a graduate of UT Austin and the other a long-time staff member there) we often hear the UT athletic song ‘The Eyes of Texas Are Upon You’. The melody is easy and friendly (everyone else knows it as “I’ve been working on a railroad”). The lyrics are [...]
Related posts:We pray with closed eyes
“I can look into his eyes and just tell he is lying”
Patent litigation and wonder in East Texas
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Bourrat, P., Baumard, N., & McKay, R. (2011) Surveillance cues enhance moral condemnation. . Evolutionary Psychology, 9(2), 193-199. info:/
A genetically modified virus that can make hidden tumours light up may lead to a new and more effective way of screening for cancer. Some cancers are helpful enough to give off obvious clues to their existence. Prostate cancer, for example, can be detected as it raises the levels of a protein called PSA in the blood. Many, however, leave no such trace. Sufferers of these diseases can, therefore, remain in the dark about their condition, delaying treatment and lowering their chances of survival.... Read more »
Browne, A., Leddon, J., Currier, M., Williams, J., Frischer, J., Collins, M., Ahn, C., & Cripe, T. (2011) Cancer Screening by Systemic Administration of a Gene Delivery Vector Encoding Tumor-Selective Secretable Biomarker Expression. PLoS ONE, 6(5). DOI: 10.1371/journal.pone.0019530
The exam season may be over, but here's a simple piece of advice for next semester. Go for a brisk walk before studying and your memory of the material is likely to benefit.
Carlos Salas and his colleagues had dozens of students study 30 nouns, each displayed for 6 seconds. Some of the students went for a ten-minute walk before being presented with the words. They were told to adopt "the walking speed one would use when late to an appointment, but without the anxiety caused by such a scenario". Other students spent the same time sitting quietly looking at pictures of natural landscapes. After the study phase, some of the students went for another ten-minute walk before attempting to recall as many of the words as they could; other students sat quietly for ten minutes before their recall attempt. This meant there were four experimental groups (walk-walk, walk-sit, sit-sit, and sit-walk), depending on how the participants behaved before the study and recall phases).
The key finding is that those students who went for a walk before the study period recalled 25 per cent more words correctly compared with students who sat still before the study period. By contrast, walking versus sitting before the attempt at recall made no difference to the students' performance.
Past research has shown context-dependent effects on memory. For example, if you chew gum while learning, your recall performance will benefit if you also chew gum when attempting to retrieve memories. No evidence for this was found in this study in the sense that the students' performance was no better when their pre-recall activity (walk vs. sit) matched their pre-learning activity, perhaps because the recall test followed too soon after the learning phase, so that the effects of the earlier walk or sitting period were still ongoing.
Another detail of this study is that the researchers asked the students to report their levels of arousal and tension after the periods of sitting or walking. Arousal was higher after walking than sitting, but tension was no different. So increased arousal is a possible physiological mechanism underlying the benefits of a pre-study walk (see earlier Digest item: "Memory performance boosted while walking").
Salas and his team also looked at meta-memory: this is people's insight into their own memory processes. During the study phase, after each word appeared, the participants were asked to indicate their likelihood of recalling it correctly. Students who sat for ten minutes before studying tended to significantly overestimate their later performance. By contrast, the walkers were much more accurate. However, there was no absolute difference in the predictions made by the two groups. In other words, it seems the walkers only had superior meta-memory because walking boosted their performance to match their confidence.
"Overall, these results suggest that individuals can gain a memory advantage from a ten-minute walk before studying," the researchers said. "Given [these] positive results ... and [their] potentially important practical applications, we hope that researchers will continue to explore the relationship between walking, memory, and meta-memory."
Salas, C., Minakata, K., and Kelemen, W. (2011). Walking before study enhances free recall but not judgement-of-learning magnitude. Journal of Cognitive Psychology, 23 (4), 507-513 DOI: 10.1080/20445911.2011.532207
If you liked this post, you might also like our round-up of 9 evidence based study tips.
[This post was written by Christian Jarrett for the BPS Research Digest.]
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Salas, C., Minakata, K., & Kelemen, W. (2011) Walking before study enhances free recall but not judgement-of-learning magnitude. Journal of Cognitive Psychology, 23(4), 507-513. DOI: 10.1080/20445911.2011.532207
Yesterday, I watched as hundreds of Londoners took to the streets in a heroic attempt to clean up the mess caused by rioters and looters the night before. Looking at pictures of large crowds getting off trains with cleaning equipment in hand and marching down streets with brooms held aloft, I’ve rarely felt so proud of my city.
The clean-up operation was a great move – a positive note in an otherwise depressing week and a chance for a beleagured capital to come together and reclaim its sense of community. But the act of cleaning away the preceding day’s damage was also important. To explain why, I’m reposting this piece from a few years back about a Dutch study which showed that signs of disorder only breed more disorder. To clarify, this is in no way an attempt to explain the psychology of the riots themselves; it simply suggests another reason why the clean-up operation was a smart move.
Imagine walking through a neighbourhood and seeing graffiti, litter, and shopping trolleys strewn about the place. Are these problems to be solved, or petty annoyances that can be ...... Read more »
In part I we talked about the small percentage of female editors in Wikipedia and their shorter editing life span. In this part we'll talk about content areas female and male editor focus on, coverage of female and male-related topics and involvement in editing controversial entries.
Content areas The authors divided the data from the January 2008 data dump into 8 main areas: Arts, Geography, Health, History, Science, People, Philosophy and Religion. Then, they checked the focus areas of each editor's activity. The authors found that men focused more on Geography and Science, while women focused more on People and Arts.
January 2008 Gender distribution of editors in eight interest areas. Editors can be categorized into more than one area
The reason these data look different than those presented earlier is that they are taken from a different data pool (2008 as opposed to the more recent data used earlier).
Topics CoverageAre female-related topics covered in Wikipedia as well as male-related topics? The authors used their gender data to determine whether an article is of more interest to women or to men. Since there are so few female editors, the metrics were "subject to high relative variance and noise" so they had to use only high-activity articles where gender was known for at least 30 editors. Articles shorter than 100 bytes were exclude because they usually redirected to other articles. The authors ended up with a sample of 59,579 articles.
Articles were declared "male" if they were in the bottom quintile (lowest 20%) of female editing activity, "neutral" if they were in the third (center) quintile, and "female" if they were in the top quintile.
Male articles are significantly longer than female articles (33,301 and 28,434 bytes respectively, t-Test, p < 0.001). Neutral articles are the longest at 36,511 bytes. Since the authors used the articles' length as a crude measurement of quality, they concluded that coverage of female topics is indeed lacking. They hypothesized that neutral articles are longer because they appeal to editors of both genders and therefore receive more overall attention.
For an additional analysis, the authors used the movie recommender web site MovieLens, which has self-reported gender information from over 80% of users who started using MovieLens before May 2003 (when they stopped asking about gender). 32% of the site's users were females. The authors mapped each movie to its Wikipedia article and excluded movies with less than 10 known-gender raters or movies which had no article. The remaining data set included 5,850 movies. The Article Length was the dependent variable, "Movie Gender" the independent variable and Movie Popularity, Movie Quality and Movie Age were the control variables. Articles about "male" movies were longer than those about "female" movies.
However, when articles about Nobel Prize winners and recipients of the Academy Award for Best Actor/Actress were analysed, it was found that they are about of equal length. So, the length gender gap isn't noticeable for very popular and/or important articles.
Controversial TopicsThe authors hypothesized that "Females tend to avoid controversial or contentious articles." They determined controversial articles according to whether the articles were protected or not, reasoning that Wikipedia tend to lock articles which are often vandalized or subject to content disputes. 5.20% of the “female” articles were protected, compared with 2.39% of the “male” articles. Female editors are actually more likely to be involved in controversial articles.
Next time: are women less likely to be blocked? Are edits by women more likely to be reverted?
Lam, S., Uduwage, A., Dong, Z., Sen, S., Musicant, D. R., Terveen, L., & Terveen, J. (2011). WP:Clubhouse? An Exploration of Wikipedia’s Gender
Imbalance WikiSym’11, October 3–5, Mountain View, California
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Lam, S., Uduwage, A., Dong, Z., Sen, S., Musicant, D. R., Terveen, L., & Terveen, J. (2011) WP:Clubhouse? An Exploration of Wikipedia’s Gender Imbalance. WikiSym’11, October 3–5, Mountain View, California. info:/
A few days ago I talked a little bit about the interactions between stress and neurogenesis, and the way that this might impact symptoms of depression. But it turns out that there’s even more to the way stress affects the body than impacting neurogenesis, and the long term effects could in turn affect the way [...]... Read more »
Warner-Schmidt JL, Vanover KE, Chen EY, Marshall JJ, & Greengard P. (2011) Antidepressant effects of selective serotonin reuptake inhibitors (SSRIs) are attenuated by antiinflammatory drugs in mice and humans. Proceedings of the National Academy of Sciences of the United States of America, 108(22), 9262-7. PMID: 21518864
As you sit in the rush hour queues, pity the poor guy or girl directing the traffic, and imagine the fumes they are breathing in. In Brazil, with rapidly expanding car ownership, but not necessarily expanding road space, this is an increasing problem.
A recent study* in the city of Santo Andre, part of the metropolitan region of Sao Paulo, focused on traffic controllers. The study focused on male, non smoking, traffic controllers who had been exposed for over 3 years. As the authors note, one criticism of the study is that it might actually underestimate health concerns, as unhealthy controllers were excluded from the test group to achieve homogeneity. Thus the subjects might be constitutively more able to adapt to air pollution, or just have healthier working practices.
The study concentrated on particles in the air (from dust, car exhaust etc) and ozone. The level of particulate matter has fallen in recent years, below the official limits of 50 and 25 ug/m3 for PM10 and PM2.5 respectively (PM 10 and 2.5 are different particle sizes), but that is still considered hazardous by many observers. Road dust accounts for about 30% of air pollution and is mainly composed of PM 10 particles, so the authors concentrated on this size in particular. Furthermore ozone levels are increasing, especially at times of high temperatures and low humidity. High ozone has been associated with cardiovascular disease.
They found that both PM10 particulates and ozone were associated with increased blood pressure, but in different ways. PM10 pollution caused a blood pressure rise almost immediately, which still remained 4 hours later, whilst the effect of ozone delayed for 2 hours of exposure, but was still apparent 5 hours later.
So, the traffic controllers are suffering measurable cardiovascular effects every day, continuing even when the pollution is removed, and in quite a stressful job. It might not end there. The so called "interior diesel" used in some cities such as Santo Andre has a lot more sulphur than the diesel distributed in the main cities (1,200 vs 500 ppm), which has been shown to cause endothelial disfunction, oxidative stress, and probably long term hypertension.
It's a dangerous job, standing in the middle of traffic, in more ways than one.
Sérgio Chiarelli P, Amador Pereira LA, Nascimento Saldiva PH, Ferreira Filho C, Bueno Garcia ML, Ferreira Braga AL, & Conceição Martins L (2011). The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil. Environmental research, 111 (5), 650-5 PMID: 21570068
*P.S. Chiarellietal et al 2011. The association between air pollution and blood pressure in traffic controllers in SantoAndre, Sao Paulo, Brazil Environmental Research 111 650–655
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Sérgio Chiarelli P, Amador Pereira LA, Nascimento Saldiva PH, Ferreira Filho C, Bueno Garcia ML, Ferreira Braga AL, & Conceição Martins L. (2011) The association between air pollution and blood pressure in traffic controllers in Santo André, São Paulo, Brazil. Environmental research, 111(5), 650-5. PMID: 21570068
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