- September 13, 2009
- 02:44 PM
- 1,071 views
Revamped Hubble breaks new ground
by sarah in One Small Step
Quick on the heels of NASA’s showcasing of the first images taken by a reborn Hubble Space Telescope come a pair of papers posted to astro-ph showing a glimpse of Hubble potential new power. These papers, by a collaboration of US, Swiss and Dutch astronomers, report the detection of galaxies using Hubble’s new optical/infrared camera [...]... Read more »
R. J. Bouwens, G. D. Illingworth, P. A. Oesch, M. Stiavelli, P. van Dokkum, M. Trenti, D. Magee, I. Labbe, M. Franx, & M. Carollo. (2009) z~8 galaxies from ultra-deep WFC3/IR Observations over the HUDF. ApJL. arXiv: 0909.1803v1
P. A. Oesch, R. J. Bouwens, G. D. Illingworth, C. M. Carollo, M. Franx, I. Labbe, D. Magee, M. Stiavelli, M. Trenti, & P. G. van Dokkum. (2009) z~7 Galaxies in the HUDF: First Epoch WFC3/IR Results. ApJL (submitted). arXiv: 0909.1806v1
- September 13, 2009
- 08:00 AM
- 727 views
Logging On for Psychotherapy
by Shaheen Lakhan in Brain Blogger
The explosion of the Internet allows people to use their computer for things that previously needed to be done in person. Now, communicating with friends and family, networking with business contacts, shopping, banking, and a host of other activities, can be done from almost anywhere in the world. While the convenience of these Internet activities [...]... Read more »
Gorini, A., Gaggioli, A., Vigna, C., & Riva, G. (2008) A Second Life for eHealth: Prospects for the Use of 3-D Virtual Worlds in Clinical Psychology. Journal of Medical Internet Research, 10(3). DOI: 10.2196/jmir.1029
Kessler, D., Lewis, G., Kaur, S., Wiles, N., King, M., Weich, S., Sharp, D., Araya, R., Hollinghurst, S., & Peters, T. (2009) Therapist-delivered internet psychotherapy for depression in primary care: a randomised controlled trial. The Lancet, 374(9690), 628-634. DOI: 10.1016/S0140-6736(09)61257-5
Palermo, T., Wilson, A., Peters, M., Lewandowski, A., & Somhegyi, H. (2009) Randomized controlled trial of an Internet-delivered family cognitive–behavioral therapy intervention for children and adolescents with chronic pain. Pain. DOI: 10.1016/j.pain.2009.07.034
Riva G. (2009) Interreality: A New Paradigm for E-health. Studies in health technology and informatics, 3-7. PMID: 19592718
- September 13, 2009
- 01:20 AM
- 1,050 views
On the loss of life in landslides during the 1949 Khait earthquake
by Dr Dave in Dave's Landslide Blog
Regular readers will know that one of my interests lies in trying to get a better understanding of the loss of life associated with landslides. A key realisation of this work for me has been that earthquake-triggered slides cause a very substantial proportional (probably in fact the majority) of fatalities is mass movement events. Unfortunately our understanding of seismically-driven landslides, and their impacts, remains poor, certainly in comparison with rainfall induced slides. For that reason, work to re-examine past seismically-driven events is very welcome, helping us to get a much better understanding of the range of processes and impacts in these events.One significant but until now slightly elusive such event has been the 1949 Khait earthquake. This was a Mw=7.4 event on 10th July 1949 in the Tien Shan mountains of what is now Tajikistan, but was then the Soviet Union. The timing and location of this event, soon after the war in an area about which the Soviet Union was very secretive, has meant that it has been very difficult to determine any details about the landslides that were triggered in the earthquake. However, some rather speculative reports have suggested that the impacts were very large - for example this article in Mountain Research and Development reported a huge landslide at a site that it termed Borgulchak Rock. This slide was reported to have travelled 12 km. Some reports, such as the Wikipedia article on this landslide, have suggested a death toll as high as 28,000 people, although to be fair this may well be something of a misinterpretation of the original source.An article in press in the journal Engineering Geology, by Steve Evans and colleagues (Evans et al. 2009 in press) seeks to re-examine the landslides triggered by this earthquake. Unusually for a science paper the article is a ripping-good read. The paper re-evaluates the Khait landslide, and the other large slide that was triggered in the earthquake, providing a rational analysis of the likely impacts of the mass movements.First, they look at the Khait landslide (termed in the paper as a rockslide / loess flow), which is still clearly visible in the landscape, even on the low resolution Google Earth imagery available for this area:For the Khait landslide they conclude that the volume was probably rather lower than earlier estimates have suggested. The other landslide considered is a very large and complex flowslide that swept down the Yasman Valley, covering about 20 km. This slide had multiple source areas on the southern side of the valley:They conclude that this is a rather destructive loess flow slide with a volume of about 245 million cubic metres. Remarkably it travelled over a slope with an angle of just two degrees!Evans et al. (2009) then consider the fatalities caused by the landslides. By looking at contempory reports of the population of the Khait area and census data on settlement size and population density they reject earlier estimates of the loss of life. For the Khait landslide itself they conclude that about 800 fatalities is probably a reasonable estimate - note that this very considerably less than earlier estimates. For the Yasman Valley flowslide they estimate about 4,000 fatalities, and they determine that there were probably a further 2,400 deaths. This gives a total fatality count of about 7,200 - far lower than previous counts, but still substantial of course.In conclusion, this is a very important contribution, filling in another gap in our understanding of previous landslide impacts. Steve and his colleagues have also just published a similar paper (Evans et al. 2009) re-examining the 1960 Huascaran rock avalanche in Peru. This will be the topic of an upcoming post.ReferenceEvans, S., Roberts, N., Ischuk, A., Delaney, K., Morozova, G., & Tutubalina, O. (2009 in press). Landslides triggered by the 1949 Khait Earthquake, Tajikistan, and associated loss of life Engineering Geology DOI: 10.1016/j.enggeo.2009.08.007Evans, S., Bishop, N., Fidel Smoll, L., Valderrama Murillo, P., Delaney, K., & Oliver-Smith, A. (2009). A re-examination of the mechanism and human impact of catastrophic mass flows originating on Nevado Huascarán, Cordillera Blanca, Peru in 1962 and 1970 Engineering Geology, 108 (1-2), 96-118 DOI: 10.1016/j.enggeo.2009.06.020... Read more »
Evans, S., Roberts, N., Ischuk, A., Delaney, K., Morozova, G., & Tutubalina, O. (2009) Landslides triggered by the 1949 Khait Earthquake, Tajikistan, and associated loss of life. Engineering Geology. DOI: 10.1016/j.enggeo.2009.08.007
Evans, S., Bishop, N., Fidel Smoll, L., Valderrama Murillo, P., Delaney, K., & Oliver-Smith, A. (2009) A re-examination of the mechanism and human impact of catastrophic mass flows originating on Nevado Huascarán, Cordillera Blanca, Peru in 1962 and 1970. Engineering Geology, 108(1-2), 96-118. DOI: 10.1016/j.enggeo.2009.06.020
- September 12, 2009
- 11:31 PM
- 548 views
Growth Hormone for Survival: It's not always controversial
by staticnrg in survive the journey
"Hypopituitary adults have a reduced life expectancy, with a 2-fold higher risk of death for cardiovascular disease compared with that in the control population, and [growth hormone deficiency] has been considered the underlying factor influencing this increased mortality."Lately growth hormone has been given a bad rap because of the controversy of its abuse by healthy, adult athletes and body-builders. That's actually very sad when there is a sizable body of chronically afflicted, growth hormone deficient adults. Hypopitiutarism and panhypopituitarism due to pituitary adenomas, surgery as treatment, and/or infarction leaves most Cushing's Disease survivors with growth hormone deficiency (GHD).According to recent research, quoted here at Stanford and reiterated by Dr. Theodore Friedman, "GH appears to be one of the first hormones to be lost in patients with pituitary tumors and nearly all patients with two or more other pituitary deficiencies also lack GH." In a recent issue of Pituitary, a study titled "Effects of 5 years of growth hormone (GH) replacement therapy of cardiac parameters and physical performance in adults with GH deficiency" caught my eye. Although not really news to me, it was nice to see some more validation. The research is outlined exceptionally well, with concise but thorough discussion and analysis.The bottom line: There may be a slight increase in blood pressure and left ventricular mass with treatment, but this is greatly offset by "positive effects on exercise capacity and maximum oxygen uptake". Another study states:...there is no doubt that adult patients with hypopituitarism and GH deficiency have an increased CV risk (odds ratio of 2 for men and 3.5 to 4 for women). " Improvement of systolic and diastolic pressures, lipid profiles, and plaque formation are also documented. A significant decrease in IMT and CRP were favorable outcomes of GH replacement therapy.GHD has also been linked to apathy, fatigue, lack of motivation and more. Thus, it becomes not only an issue of mortality, but also an issue of quality of life. I hope the medical community will educate themselves about GHD. The authors of the Pituitarystudy elaborated well: GHD is associated with hypercoagulability, abdominal obesity, insulin resistance, unfavorable lipid profile, atherosclerosis, increased blood pressure (BP), decreased exercise performance and with reduced pulmonary capacity, left ventricular (LV) mass and LV systolic performance... Cenci, M., Soares, D., Spina, L., Lima Oliveira Brasil, R., Lobo, P., Mansur, V., Gold, J., Michmacher, E., Vaisman, M., & Conceição, F. (2009). Effects of 5 years of growth hormone (GH) replacement therapy on cardiac parameters and physical performance in adults with GH deficiency Pituitary DOI: 10.1007/s11102-009-0182-2For more help with Cushing's, visit http://www.cushings-help.com
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Cenci, M., Soares, D., Spina, L., Lima Oliveira Brasil, R., Lobo, P., Mansur, V., Gold, J., Michmacher, E., Vaisman, M., & Conceição, F. (2009) Effects of 5 years of growth hormone (GH) replacement therapy on cardiac parameters and physical performance in adults with GH deficiency. Pituitary. DOI: 10.1007/s11102-009-0182-2
- September 12, 2009
- 09:45 PM
- 1,748 views
A quick note on flagella, and their evolution
by Psi Wavefunction in Skeptic Wonder
First off, 'flagella' and 'cilia' tend to be used interchangeably. I prefer to call them flagella, out of habit, but there's some who argue 'flagellum' should be reserved for bacteria, who have a fundamentally different system from us; while we have 'cilia'. Another note: 'flagella' is spelled with two l's, 'cilia' with one. Took me about two months of protistology to learn that. (also, I consistently spelled 'axopodia' as 'auxopodia', thanks to a plant biology research background. Curse you, auxin!)Interestingly the flagellar structures seem to be fairly conserved in evolution, and are often used in taxonomy. Most eukaryotes are fundamentally biflagellate, meaning their flagellar systems, whatever they are, are likely derived from modifications of an ancestral biflagellate form, and retaining the double basal bodies. Flagella can be lost, but the basal bodies that anchor them tend to remain behind. Conversely, basal bodies can be duplicated, as they have, for example, in parabasalia, which are tetraflagellate; entire basal body units (kinetids) can also be multiplied, up to extremes such as in ciliates. (the developmental organisation of ciliate flagella is an endlessly fascinating subject, and if all goes well, would be my research focus after BSc. =D *knocks on her head wood)In contrast, a few eukaryotes have what is fundamentally a single flagellum - those are unikonts, which include amoebozoa (eg. cellular slime moulds) and opisthokonts (ass-tails, eg. fungi, choanoflagellates...and us). It is intuitive to think of flagella as propelling the organism forward. But not everything is about sperm: most eukaryotic organisms actually pull themselves by flagellar motion, thereby defining the location of the flagellum as the anterior end, rather than posterior. Another distinction is between isokonts (equal flagella) and heterokonts (unequal flagella) - in the former, the two flagella are structurally identical, whereas in the latter they differ, often with little protrusions (mastigonemes) lining one of them.Actually, scratch everything I just said about opisthokonts and amoebozoa being unikonts together. Missed a memo... there's this amitochondriate amoeba Breviata (TCoO post here and picture here), previously of uncertain placement or classified as an archamoeba. Despite having a single flagellum, it seems to have a double basal body, one of them unflagellated (Walker et al. 2006 JEM). Turns out that evidence suggests it's a basal amoebozoan, which would kill TC-S' unikont/bikont division (indicated in grey below):(Roger & Simpson 2009 Curr Biol; numbers indicate ancestral number of basal bodies/flagellar unit, asterisk indicates one basal body is unflagellated, and the 2+ in Breviata indicates there may have been more that two basal bodies/unit.)So to summarise:kinetid - unit of basal bodies + flagella; not all basal bodies must have a flagellum (but the flagella must be anchored to a basal body each)opisthokont - organisms with posterior flagellation; most eukaryotes have flagella at the front of their movement.heterokont - both (or more) flagella structurally differentisokont - both (or more) flagella are the sameunikont - organisms with single basal body/flagellum per kinetidbikont - organisms with double (or more) basal body per kinetidmastigonemes - little protrusions regularly lining a flagellum; for increasing a flagellum's surface area.centriole/basal body - generally interchangeablecilium/flagellum - generally interchangeable(kont means tail, by the way)I noticed I throw those terms a lot in other posts without really explaining them; so hopefully this post can be some sort of reference, just in case!There's more to it, but someone has some protist-oriented microscopy for me to do. I love Saturday nights!Roger, A., & Simpson, A. (2009). Evolution: Revisiting the Root of the Eukaryote Tree Current Biology, 19 (4) DOI: 10.1016/j.cub.2008.12.032WALKER, G., DACKS, J., & MARTIN EMBLEY, T. (2006). Ultrastructural Description of Breviata anathema, N. Gen., N. Sp., the Organism Previously Studied as "Mastigamoeba invertens" The Journal of Eukaryotic Microbiology, 53 (2), 65-78 DOI: 10.1111/j.1550-7408.2005.00087.x... Read more »
Roger, A., & Simpson, A. (2009) Evolution: Revisiting the Root of the Eukaryote Tree. Current Biology, 19(4). DOI: 10.1016/j.cub.2008.12.032
WALKER, G., DACKS, J., & MARTIN EMBLEY, T. (2006) Ultrastructural Description of Breviata anathema, N. Gen., N. Sp., the Organism Previously Studied as "Mastigamoeba invertens". The Journal of Eukaryotic Microbiology, 53(2), 65-78. DOI: 10.1111/j.1550-7408.2005.00087.x
- September 12, 2009
- 09:13 PM
- 630 views
Who’s Out First?
by Journal Watch Online in Journal Watch Online
Invasive species need to be removed in the right order
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Collins, P., Latta, B., & Roemer, G. (2009) Does the Order of Invasive Species Removal Matter? The Case of the Eagle and the Pig. PLoS ONE, 4(9). DOI: 10.1371/journal.pone.0007005
- September 12, 2009
- 07:15 PM
- 659 views
Destabilizing old memories with novel information
by William Lu in The Quantum Lobe Chronicles
What if one day we could disrupt unwanted consolidated memories like those of old traumatic experiences or even unforgettable heartbreaks and replace them with novel and more pleasant ones? Sounds like a tagline from the 2004 Oscar-winning film Eternal Sunshine of the Spotless Mind doesn't it? Published in this month's issue of Learning & Memory, a study by Winters, Tucci, and DaCosta-Furtado over at the University of Guelph, Canada have managed to bring us one step closer to making this seeminly far-fetched idea a reality. They had rats explore sample objects and some time later injected them with either an NMDA receptor antagonist known as MK-801 or a control saline solution before reactivating the object memory. The authors found that the reconsolidation of young or weakly encoded memories were disrupted by MK-801 regardless of the reactivation conditions. However, when they increased the amount of sample object exploration or the time between sample phase and reactivation (older and stronger memories) the effect of MK-801 was abolished during reconsolidation unless (now this is the interesting part) salient novel contextual information was present during memory reactivation. Their findings support the hypothesis that the reconsolidation process enables modification of existing memories.Could this be a future treatment option for patients suffering from PTSD? How about for less severe cases like those who just can't get over that one ex. For now it seems like we'll be seeing it "only in theaters".Winters, B., Tucci, M., & DaCosta-Furtado, M. (2009). Older and stronger object memories are selectively destabilized by reactivation in the presence of new information Learning & Memory, 16 (9), 545-553 DOI: 10.1101/lm.1509909... Read more »
Winters, B., Tucci, M., & DaCosta-Furtado, M. (2009) Older and stronger object memories are selectively destabilized by reactivation in the presence of new information. Learning , 16(9), 545-553. DOI: 10.1101/lm.1509909
- September 12, 2009
- 06:55 PM
- 605 views
The Cost and Duration of Drug Discovery Must Decrease
by Michael Long in Phased
Ray Dorsey (University of Rochester, New York) and coworkers have shown that biomedical scientists are not making optimal use of the money they receive for research. This news feature was written on September 12, 2009.... Read more »
Dorsey, E. R., Thompson, J. P., Carrasco, M., de Roulet, J., Vitticore, P., Nicholson, S., Johnston, S. C., Holloway, R. G, & Moses III, H. (2009) Financing of U.S. Biomedical Research and New Drug Approvals across Therapeutic Areas. PLoS ONE, 4(9). DOI: 10.1371/journal.pone.0007015
- September 12, 2009
- 02:50 AM
- 650 views
Improved image quality from your camera phone
by Stuart Watson in Optical Futures
The demand for consumer electronics to get smaller, lighter and cheaper, is a stimulus for great ingenuity. Cell phones are a classic example where electrical engineers and designers are constantly working to put a whole lot more into ever smaller spaces. And now that cameras are almost as standard a feature in these devices as the ring tone, optical engineers must also devise increasingly clever ways to shrink the optics while improving their performance.
read more... Read more »
Zhou, G., Leung, H., Yu, H., Kumar, A., & Chau, F. (2009) Liquid tunable diffractive/refractive hybrid lens. Optics Letters, 34(18), 2793. DOI: 10.1364/OL.34.002793
- September 11, 2009
- 10:34 PM
- 1,453 views
Bat-eating tits!
by Jeremy Yoder in Denim and Tweed
Like pretty much anyone else writing about this, I'm in it for the headline. Well, maybe 30% for the headline -- this is also just freaky natural history. A paper in Biology Letters reports that great tits (Parus major -- basically big chickadees) will hunt and eat hibernating bats [$-a] if they can't find other food sources.
The paper reports on ten years of recorded bat-eating by a population of great tits in Hungary, capped by two years of systematic observations and a couple simple experiments. Are the tits hunting bats because other food is scarce? The authors put out birdseed and bacon near the bat cave, and observed that the birds killed many fewer bats. Do the tits use audio cues to find their prey? The authors played a tape recording of bats calling, and watched as the birds oriented to the sound and approached the speaker. There are also a number of grisly photos of tit-killed bats.
This is really the kind of work that attracts most field biologists to science in the first place -- a wild, interesting observation that provides an excuse to do some really unusual (and thorough) birdwatching. More complicated science will follow, I hope, like an estimate of the selective advantage this new food source provides to the birds. But it all starts with an incredible story.
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You might want to count your fingers after hand-feeding a great tit. Photo by joyrex.
Reference
Estok, P., Zsebok, S., & Siemers, B. (2009). Great tits search for, capture, kill and eat hibernating bats Biology Letters DOI: 10.1098/rsbl.2009.0611
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Estok, P., Zsebok, S., & Siemers, B. (2009) Great tits search for, capture, kill and eat hibernating bats. Biology Letters. DOI: 10.1098/rsbl.2009.0611
- September 11, 2009
- 04:50 PM
- 699 views
Rugged Enzymes for Chemical Synthesis
by Michael Long in Phased
Zhi Li (National University of Singapore) and coworkers have enhanced the utility of enzymes for chemical synthesis, through the aid of metal nanoparticles. This news feature was written on September 11, 2009.... Read more »
Wang, W., Xu, Y., Wang, D. I. C., & Li, Z. (2009) Recyclable Nanobiocatalyst for Enantioselective Sulfoxidation: Facile Fabrication and High Performance of Chloroperoxidase-Coated Magnetic Nanoparticles with Iron Oxide Core and Polymer Shell. Journal of the American Chemical Society, 131(36), 12892-12893. DOI: 10.1021/JA905477J
- September 11, 2009
- 03:52 PM
- 502 views
The Neural Case for Health Care Reform
The moral case for health reform was not the focus of President Obama’s address to Congress Wednesday night. It did, however, form the core of the most eloquent and compelling section of the speech, which followed the invocation of the late Senator Ted Kennedy:
That large-heartedness – that concern and regard for the plight of [...]... Read more »
Miller, G., Chen, E., Fok, A., Walker, H., Lim, A., Nicholls, E., Cole, S., & Kobor, M. (2009) Low early-life social class leaves a biological residue manifested by decreased glucocorticoid and increased proinflammatory signaling. Proceedings of the National Academy of Sciences, 106(34), 14716-14721. DOI: 10.1073/pnas.0902971106
- September 11, 2009
- 01:15 PM
- 1,828 views
engineering photo-activable proteins
by 96well in Reportergene
Plants contain proteins subjected to conformational changes in direct response to light irradiation. Moieties of those proteins, like the LOV2 domain from the Avena sativa Phototropin1 can be used to introduce light-operated switches onto other functional proteins. In a recent letter to Nature, Yi Wu and colleagues (Carolina University) poked at the Stratagene Quickchange kit to obtain a constitutive active Rac protein that was coupled to the vegetable LOV2 light switch using an overlapping PCR approach. The result of such a cut and paste was genetically encoded into HeLa, HEK93 and MEF/3T3 cell lines. Then, by irradiating whole cells or even localized micro-spot on the cell surface, PA-Rac1 was sufficiently photo-activated to generate polarized cell movements. In other words, light was controlling the motility of living cells via photoactivable Rac. Structural studies indicate that the Rac-LOV2 interface can be engineered to cage other proteins. Engineering and Biology are getting married. If you are a kick ass engineer, consider hacking biology at Ginkgo BioWorks, they are hiring.Wu, Y., Frey, D., Lungu, O., Jaehrig, A., Schlichting, I., Kuhlman, B., & Hahn, K. (2009). A genetically encoded photoactivatable Rac controls the motility of living cells Nature, 461 (7260), 104-108 DOI: 10.1038/nature08241
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Wu, Y., Frey, D., Lungu, O., Jaehrig, A., Schlichting, I., Kuhlman, B., & Hahn, K. (2009) A genetically encoded photoactivatable Rac controls the motility of living cells. Nature, 461(7260), 104-108. DOI: 10.1038/nature08241
- September 11, 2009
- 11:30 AM
- 744 views
American Heart Association says the verdict is in - sugar is bad
by Travis Saunders, MSc in Obesity Panacea
In the past, I have written several posts about sugar (mainly fructose and high fructose corn syrup, aka HFCS), and how it is a driving force behind the current obesity epidemic. The evidence is compelling - the intake of added sugars (especially HFCS) has dramatically increased over the past 30 years, an increase which is mirrored by the increased prevalence of obesity. Further, these added sugars are "empty" calories, which tend to displace other foods that contain more nutrients. Then there are the many ways that sugar (again, especially HFCS) disrupts both metabolism and the hormones that signal satiety, resulting in increased health risk as well as increased food intake (outlined wonderfully in this powerpoint presentation by Dr Robert Lustig of the University of California at San Fransisco). That's right - sugar can actually make you more hungry! The insulin response to sugar and resulting lethargy may result in decreased energy expenditure as well. In short, sugar does many bad things to the human body, and it should be limited to a very small portion of our daily diet.
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Johnson, R., Appel, L., Brands, M., Howard, B., Lefevre, M., Lustig, R., Sacks, F., Steffen, L., Wylie-Rosett, J., & , . (2009) Dietary Sugars Intake and Cardiovascular Health. A Scientific Statement From the American Heart Association. Circulation. DOI: 10.1161/CIRCULATIONAHA.109.192627
- September 11, 2009
- 08:00 AM
- 1,235 views
The small brain of the biggest shark in the world
by Zen Faulkes in NeuroDojo
“We’re going to have some problems getting this under the microscope...”There are just times you’d like to be a fly on the wall when certain science projects are being planned. I can’t quite imagine the conversations that led up to this paper. “Let’s look at the brain of the biggest fish in the world.” (I suppose the fish start small and have to grow up big. But still.)The brains of sharks are interesting, in part because they much larger than people would think. People tend to think of sharks as primitive (how many shark documentaries have used the phrase, “unchanged for millions of years”?), and primitive means small brains. But compared to body size, shark brains are often as big as birds’ and mammals’.And when thinking about evolution of brains, extremes are often very informative. The whale shark (Rhincodon typus) is not only extreme in its size (as noted, they’re bigger than any other fish in the world), but extreme in its diet: it’s a filter feeder, which is not the first thing that comes to mind when people hear the words, “giant shark.”This paper is not only interesting because the species is unusual for neurobiology, it’s interesting because it applies a technique that is used a lot for humans, but quire rarely for other beasties: magnetic resonance imaging (MRI). Now, this is not fMRI, which is constantly in the science headlines: this is purely anatomical data, not imaging the brain of a live shark.Although the whale shark has a massive brain in absolute terms, it turns out that it isn’t very large relative to its body mass compared to other sharks. In fact, it’s small. In a situation like this, there are two hypotheses that come to mind. The first is that the feature was inherited from a common ancestor, in which case, you6d predict that the whale shark’s relatives also have small brains. The second is that the feature may be an adaptation to the particular ecology of the species, and the prediction there would be that species with the most similar lifestyle would have small brains.In this case, the whale shark has a small brain in common with other large filter feeding sharks, like the basking shark (compared using previously published data). It’s easy to think that filter feeders can afford to have small brains, but the authors caution that social behaviours in sharks and allies is another factor that is often strongly correlated with brain size.When looking at individual regions of the brain, the whale sharks also had something in common with other oceanic, pelagic sharks, but not their relatives: a very large cerebellum. Cerebellum is usually described as being involved in motor coordination. Why would these open ocean sharks need such a large cerebellum? The authors suggest that perhaps the use of that open ocean is more complex than you might expect. The sharks are not just lazing around at the top of the water, but making significant vertical migrations and travel for very long distances. These possibilities seem a bit foggy, however, based on the traditional notions of cerebellar function. Usually, the cerebellum is involved in coordinating fine movements, not long range navigation. There may be some other undiscovered ecological or behavioural force in play shaping the brains of these massive animals.ReferenceYopak, K., & Frank, L. (2009). Brain Size and Brain Organization of the Whale Shark, Rhincodon typus, Using Magnetic Resonance Imaging Brain, Behavior and Evolution, 74 (2), 121-142 DOI: 10.1159/000235962Photo by user TANAKA Juuyoh (田中十洋) on Flickr, used under a Creative Commons license.... Read more »
Yopak, K., & Frank, L. (2009) Brain Size and Brain Organization of the Whale Shark, Rhincodon typus, Using Magnetic Resonance Imaging. Brain, Behavior and Evolution, 74(2), 121-142. DOI: 10.1159/000235962
- September 11, 2009
- 08:00 AM
- 1,395 views
Influenza virus reassortment, then and now
by Vincent Racaniello in virology blog
I thought you might like to see how I did a similar experiment in 1979 – a very different era for laboratory techniques.... Read more »
Racaniello VR, & Palese P. (1979) Influenza B virus genome: assignment of viral polypeptides to RNA segments. Journal of virology, 29(1), 361-73. PMID: 430594
- September 11, 2009
- 06:00 AM
- 751 views
Science News: Week of September 6, 2009
by Susan Steinhardt in BioData Blogs
Our weekly compilation of science news for the week of September 6, 2009.... Read more »
Schnuelle P, Gottmann U, Hoeger S, Boesebeck D, Lauchart W, Weiss C, Fischereder M, Jauch KW, Heemann U, Zeier M.... (2009) Effects of donor pretreatment with dopamine on graft function after kidney transplantation: a randomized controlled trial. JAMA : the journal of the American Medical Association, 302(10), 1067-75. PMID: 19738091
Münch, T., da Silveira, R., Siegert, S., Viney, T., Awatramani, G., & Roska, B. (2009) Approach sensitivity in the retina processed by a multifunctional neural circuit. Nature Neuroscience. DOI: 10.1038/nn.2389
Zelada-Guillén, G., Riu, J., Düzgün, A., & Rius, F. (2009) Immediate Detection of Living Bacteria at Ultralow Concentrations Using a Carbon Nanotube Based Potentiometric Aptasensor. Angewandte Chemie International Edition. DOI: 10.1002/anie.200902090
Childs, R., Palma, A., Wharton, S., Matrosovich, T., Liu, Y., Chai, W., Campanero-Rhodes, M., Zhang, Y., Eickmann, M., Kiso, M.... (2009) Receptor-binding specificity of pandemic influenza A (H1N1) 2009 virus determined by carbohydrate microarray. Nature Biotechnology, 27(9), 797-799. DOI: 10.1038/nbt0909-797
- September 11, 2009
- 03:45 AM
- 1,588 views
Finger-growing dinoflagellate (cute!)
by Psi Wavefunction in Skeptic Wonder
Why must I spoil the plot by peeking into advance online publications instead of waiting for the damn issue to come out, like normal people do? Especially with an 8am class coming up so soon...Anyway, apparently Ceratium ranipes, a photosynthetic dinoflagellate, decided to grow plastid-stuffed 'fingers' during daylight:(Pizay et al. 2009 Protist, in press; light period)And retracts them back in for the night:(Pizay et al. 2009 Protist, in press; dark period)In case you're not convinced these are the same organism:(Pizay et al. 2009 Protist, in press; sequence from a single individual removed from light, T measures minutes of darkness) (a video of that would be so awesome...!)Chloroplasts fluoresce red when hit by UV light (see my own example with a diatom); take a look at those fingers:(Pizay et al. 2009 Protist, in press. Left: formalin-preserved C.ranipes with a daytime morphology; the inset shows UV autofluorescense of the plastids: note their concentration in the 'fingers'. The bluish/whitish subinset shows Calcofluor White staining, which indicates the presence of thecal plates on the fingers. Right: transitional morphology at the end of the day: note how the plastids migrated inwards away from the fingers.)This raises some cell biology-related questions: how is plastid movement coordinated and regulated? What does the genetic developmental pathway look like for those fingers, and how does it interact with whatever immediately respond to light? More importantly, why does this thing seemingly waste its time growing and retracting fingers, when it could have just kept them protruded during dark hours?Could be just a low cost glitch in the system, or perhaps there is something to it. After all, perhaps it wouldn't take much to lose the finger retraction ability - so is there some cost when that happens, thereby keeping this process going? Sinking may have something to do with it - many planktonic algae sink for the night and float back up during the day. Fingers may drastically slow down the sinking speed. However, there's no data yet showing any vertical migration in C.ranipes (Pizay et al. 2009 Protist). Could be a relic from an ancestor that did sink, but then why hasn't this behaviour been found earlier, and in more dinos?Another idea in the same paper is that the fingers get in the way of directed swimming; during daylight hours, you sacrifice your swimming ability for a larger photosynthetic capacity, but it may be advantageous to put away the tackle in the absense of light.This reminds me of two things: 1) plant leaves - increasing the surface area exposed to surroundings for gas exchange, as well as the area exposed to light. Sort of a convergence. 2) Many 'radiolaria' have algal symbionts they use for photosynthesis, and they too spread them out towards the tips of the host's filopodia during daytime, and retract them inwards for the night. So whatever you do, don't dangle your plastids in plain view when they're not in use.---Pizay, M., Lemée, R., Simon, N., Cras, A., Laugier, J., & Dolan, J. (2009). Night and Day Morphologies in a Planktonic Dinoflagellate Protist DOI: 10.1016/j.protis.2009.04.003... Read more »
Pizay, M., Lemée, R., Simon, N., Cras, A., Laugier, J., & Dolan, J. (2009) Night and Day Morphologies in a Planktonic Dinoflagellate. Protist. DOI: 10.1016/j.protis.2009.04.003
- September 10, 2009
- 11:51 PM
- 667 views
Lurasidone = Asenapine = Iloperidone
by Neuropsych15 in The MacGuffin
Last week I asked, rhetorically, whether I should waste my time reviewing the published researched on the potential new antipsychotic drug Dainippon (lurasidone). Luckily for me, there isn't much (1a, 1b).Well that's not entirely true. I did come across this study titled, "公司已在美国启动供给N0的前列腺素" (2), and this one, "使用静脉注射免疫球蛋白" (3). At least, I think those are research articles..., I'm not quite sure.Anyway, the great news is that there are plenty of press releases (4, 5) to extol the virtues of this drug prior to it being reviewed by the FDA and the psychiatric community (I just made myself laugh, that never happens 6).Here are some quotes from this press releases:"lurasidone was well-tolerated and had a relatively low discontinuation rate.""Lurasidone's effect on weight was similar to placebo (median change 0.3 kg for overall lurasidone group vs. 0 kg for placebo) as was its effect on lipid and glucose measures. Lurasidone was also well tolerated with a lower overall discontinuation rate (31%) compared to placebo (43%) and few adverse event-related discontinuations (6% and 2% for the overall lurasidone group and placebo, respectively).""Adverse events seen in the trial were generally mild. The most commonly reported adverse events for lurasidone (greater than 5% and at least twice the rate of placebo) were akathisia (17.6% vs. 3.1% placebo), somnolence (11.7% vs. 5.5%), parkinsonism (6.8% vs. 0), and increased weight (5.1% vs. 2.4%).""The development program for lurasidone is intended to establish efficacy for the core symptoms of schizophrenia, characterize its safety profile and explore its effects in the treatment of cognitive impairment and other areas not adequately addressed by current therapies""If you look at the weight gain, the lipid changes, it's among the most benign of any antipsychotic drugs, clearly better than olanzapine, clozapine and Seroquel""From the point of view of efficacy and side effect profile, once a day administration, the fact that the lower dose works as well as the higher dose, I think this is going to have a very good chance of major acceptance among my colleagues"Douche bag.That last quote is from this press release (5), and that lower dose he is referring to is 40mg. I guess he didn't read this press release (4), which reported this, "also evaluated two other fixed doses of lurasidone, 40 mg/day and 120 mg/day, which did not demonstrate separation from placebo on the PANSS or CGI-S at study endpoint."Here are the reported adverse events from this article (1):From the press releases, "The most commonly reported adverse events for lurasidone (greater than 5% and at least twice the rate of placebo) were akathisia (17.6% vs. 3.1% placebo), somnolence (11.7% vs. 5.5%), parkinsonism (6.8% vs. 0), and increased weight (5.1% vs. 2.4%).""The most common adverse events reported at a frequency of at least 5% and at least twice the rate of placebo among the combined lurasidone doses in these trials were akathisia (11.6% vs. 4.7% placebo), somnolence (14.3% vs. 7.1%) and nausea (14.8% vs. 6.1%)."Then there is this beauty, "the adverse events were generally mild, such as restlessness and sleepiness." That last statement just made my third testicle descend.All side effects are from the 80mg dose.The above-referenced study had a relatively small sample size (n=90), which I think downplays the akathisia (8.9%), while the summarized studies in the press releases are larger (n=500 & n=392) and have the high rates of akathisia.Important Point: Akathisia is not a MILD side effect. Just asked anyone who has ever experienced it."These data showed that lurasidone was well tolerated with a low propensity for EPS."More Important Point: Akathisia and parkinsonism ARE extrapyramidal symptoms.Here are the side effect profiles from two other antipsychotic drugs:asenapine & risperidoneiloperidone & haloperidolWow, lurasidone has a higher report rate of akathisia than haloperidol! (17.6% versus 13.6%). Correction, that's high (really high) dose haloperidol (15mg) . Taken together, lurasidone does not look any different, just more of the same."Zyprexa and similar drugs can cause significant weight gain and have been linked to increased risk of diabetes...Lurasidone was well tolerated with a discontinuation rate nearly identical to placebo -- 40 percent versus 39 percent." Have they forgotten that there already is a class of drugs that do not cause those severe metabolic changes? They're the first generation antipsychotics."...but this class of drugs as a whole is so superior to the first generation drugs said Meltzer." In what way is that Dr. Meltzer? Efficacy? No. Side effects? Nope. Patient tolerance? No again.I'm feeling the need to be sued for defamation: Dr. Meltzer is a flabby bag of douche!There's no point in reviewing the efficacy results here. Just read any random antipsychotic clinical trial. The numbers are all the same. No new psychiatric drug, antidepresant, antipsychotic, mood stabilizer, whatever, has been shown to be more effective than its predecessors in a clinically meaningful way.Key points to remember:1. This drug is being pushed as safer. So is asenapine and iloperidone. So will any new drug on the horizon. It's marketing. You don't manipulate the identical set of brain receptors and get less side effects. You only get different side effects.2. The majority of the authors on these study are employees of the pharma company sponsoring the trial. The same is true for the asenapine and iloperidone studies. That's called bias. Double blind does not mean a damn thing.3. The remainder of the second generation antipsychotics are becoming generic. That means they will be prescribed less. That means there will be a void, which can be filled by newer more expensive drugs. Si... Read more »
Nakamura M, Ogasa M, Guarino J, Phillips D, Severs J, Cucchiaro J, & Loebel A. (2009) Lurasidone in the treatment of acute schizophrenia: a double-blind, placebo-controlled trial. The Journal of clinical psychiatry, 70(6), 829-36. PMID: 19497249
- September 10, 2009
- 11:26 PM
- 822 views
Bird sex gene identified
by hilaryml in Chicken or Egg blog
In mammals, sex is determined by genes contained on sex chromosomes – males have an X and a Y chromosome, and females have two X chromosomes. In birds things are quite different, as it is the male that has two of the same type of sex chromosome. Male birds have two Z chromosomes and female birds have a [...]... Read more »
Smith, C., Roeszler, K., Ohnesorg, T., Cummins, D., Farlie, P., Doran, T., & Sinclair, A. (2009) The avian Z-linked gene DMRT1 is required for male sex determination in the chicken. Nature, 461(7261), 267-271. DOI: 10.1038/nature08298
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