Wednesday, June 30, 2010
A paper in Nature Communications today reports that some dinosaurs regularly returned to geothermal areas to nest. The new discovery of a nesting site in Sanagasta Valley in La Rioja province, northwestern Argentina show that some neosauropods used the area to keep their eggs warm. Eighty clutches of eggs were mapped to be within 3 meters of geothermal conduits which would keep the eggs at 60–100°C for the incubations period of 1-2 months. Most of the nests contained 3 to 12 eggs but some had as many as 35, stacked in 2 tiers. The nests themselved could be as large as 2 square meters. The large number of eggs suggests that these dinosaurs were boosting their young's chances of survival -- the more you lay the more likely that more will survive.
An analysis of the elements in the eggshells and associated sediments showed that the eggs were present in the area during the Gondwanic hydrothermic cycle. This period of geothermal venting is known to have occurred between 134 to 110 million years ago. The egg shells were found to be thick and the whole eggs large, about 21 cm in diameter. The size of the eggs and the thickness of the shells is thought to have protected the eggs from the steamy, acidic enviroment found around the vents. Because the shell thickness ranged from 1.29 to 7.54 millimeters, it is suggested that the shells got thinner over the incubation period, likely due to the acidic moisture.
As of yet, no fossilized bones have been found at this site. Scientists are still looking for fossils in order to pin down the species.
Here's the story:
Tuesday, June 29, 2010
While talking with his 88 year old mother, Fallon got the idea to look into his own family who, in the past, had some very violent members. So he decided to look at his family to see if anyone possessed the brain of a serial killers. There are no current problems in any of this current family members and Fallon had 10 members submit a PET brain scan and a blood sample as part of a project to see whether his family had a risk for developing Alzheimer's disease. He found that his wife, mother, siblings, and children's scans were normal. His scan? Not so much. Put simply, Fallon states that the orbital cortex puts a brake on the amygdala, which is involved in aggression and appetites, and an imbalance of one affects the other. His own scan showed that his orbital cortex appears inactive. Yep, killer brain.
He also tested DNA for 12 genes associated with aggression and violence, zeroing in on the MAO-A gene (monoamine oxidase A) also called the "warrior gene due to its regulation of serotonin in the brain. Everyone in the family was normal. Once again, he was not, in fact he got a 100%.
Should his family, friends, and anyone he ever met be worried? Probably not. Generally, scientists believe that brain patterns and genetic makeup are not enough to make someone a psychopath. You need a third, important ingredient: abuse or violence during childhood. But even then, we can't legally say "their brains made them do it" or "their genes made them do it." But it is further evidence as to why people do the things they do.
Here's the story:
Friday, June 25, 2010
The event will start at 6:17 a.m. EDT (1017 GMT) Saturday morning, the greatest eclipse occurring at around 7:38 a.m. EDT (1138 GMT). The entire show should last about 80 minutes, so if you want to go back to bed I suggest setting your alarm for the peak of the partial eclipse. If you live in the central or western part of the U.S. then look low and to the west just before dawn, the moon will be close to the horizon (peak should be ~4:35 a.m. PDT for you guys). If you live in the eastern U.S. the partial eclipse will begin after the moon has set so you may only get to see part of it. However, if you live in the northeastern U.S. and Canada, sorry no eclipse for you. If you are in India, Japan or parts of East Asia then you will be able to see the partial eclipse, "moon illusion" included, on Saturday evening as the moon rises.
Note that no special viewing equipment is needed for viewing a lunar eclipse, but if you have a telescope, and don't mind dragging it out at 4 in the morning, you'll notice some great coloration (see first link for details). Also, the International Space Station will be visible moving from west to southeast around 4:34 a.m. PDT (altitude 25 degrees SW).
The next lunar eclipse will happen on the morning of December 21, and it'll be a full one.
For more on times, details, etc look here:
Wednesday, June 23, 2010
The case involves the website's use of the trademarked slogan "The Other White Meat." According to the letter sent to the website by the lawyers representing the National Pork Board: "We are writing you in connection with your activities at the Web site www.thinkgeek.com, wherein you have been marketing a product called 'Radiant Farms Canned Unicorn Meat' using the slogan 'Unicorn -- the new white meat.' A copy of the Web site page is attached for your reference."
Let me give you a second to read that again and let it really soak in...
Yeah, unicorn meat. Apparently the "meat" in question was a prank product launch for April Fool's Day and is described by the website as "...the sparkling, crunchy, savory meat of today's elite." And ok, I get that the industry is just trying to protect its slogan, but really April Fool's Day + unicorns = not worth the legal expenses.
See the offending website "ad" here:
and here's The Washington Post story:
(image from knowyourmeme.com)
I can, and have, written long and in depth on this topic, but I'll try to quickly sum up the Equilibrium Theory of Island Biogeography (ETIB). First you need an isolated habitat, island or otherwise -- they are great for study because they are relatively small, replicated, and isolated. The whole formation of a theory thing started when scientists noticed that as the size of a patch increased the number of species increased (not always necessarily the number individuals of a species), this is known as the Species-Area Relationship. Yeah, pretty logical right? Let's keep going with the concept though. Let's say you have a brand new island, species will immigrate to the island -- how many, which ones, and who stays? All that depends on the island itself -- how big it is and how isolated it is from the source population (usually the mainland but also other islands). An island far from the mainland is harder to get to and so has fewer species. A small island is harder to survive on and so also has fewer species. Get where I'm going with this? Now the ETIB says that there is an equilibrium point between immigration and extinction -- a balance between these two processes that determines the number of species on an island. Over time immigration increases the number of species on the island, but as you get more species on an island there are more species that have the possibility of going locally extinct (see the embedded graph).
This study looks at not-so-much the equilibrium point itself, but rather the colonization of island by bird species.
As you might guess, birds are pretty good colonizers, considering that they can fly. But also think about bird species themselves, some are widespread and undifferentiated while others are pretty limited in their distributions and can be rather specific. On islands, because of their size and isolation, this can can mean some species will exhibit morphological or genetic differentiation between individual island populations and/or the mainland source population. This study looks at ecological and geographic distributions of source population to see how recent/continuing colonizers, old colonizers, and non-colonizing/mainland species are different from each other. When you are thinking about these categories, think about them in terms of time and how long it takes a population to genetically differentiate.
In terms of ecological and geographic distribution, the author found that recent colonists tend to inhabit open habitats and are pretty abundant and widely distributed on the islands they are found. Conversely, old colonists tend to inhabit forests and their abundance and distribution depends on the species and on the island. If an old colonist has recently spread to other islands then they act like recent colonists in that they have relatively greater abundance and broader habitat distributions. In general, most of these data showed that the distributions of source populations is broader for recent colonizers than for old colonizers.
To read much more on this topic, here's the article:
Ricklefs, Robert E. (2010) Colonization of the Lesser Antilles by land birds. Ecology: Vol. 91(6), 1811-1821. (DOI: 10.1890/09-0682.1)
(image from birdquest.co.uk and algebralab.org respectively)
Friday, June 18, 2010
Wednesday, June 16, 2010
A new paper has been published in the journal Psychiatry Research titled "Is Anakin Skywalker suffering from borderline personality disorder?" is the first to come up.
This short letter provides a detailed look at the only recurrent main character to appear in all six Star Wars episodes: Anakin Skywalker, Jedi Knight and supervillan Darth Vader (kuuuhh, kuuuhh) <-- that was supposed to be Darth Vadery like breathing, in case you couldn't tell. But why does this series, and this character in particular, hold such universal appeal and success? The themes within the storyline? Pshah, too easy. More likely its this main character's personality.
The authors take "a psychodynamically oriented exploration of his life history" and show how elements within it are associated with borderline personality disorder:
1. The absence of his father and his early separation from his mother
2. The use of defense mechanisms such as splitting, projection, and infantile illusions of omnipotence
3. During his youth Anakin had problems with emotional and impulse regulation, particularly anger management
4. His dysfunctional experiences with himself and others and his quest to find himself and his identity
5. His constant fear of losing his wife and the frantic efforts to avoid it
6. His dissociative episodes: killing the Tuskan raiders who killed his mother and wiping out the Jedi younglings after turning to the dark side of the force
Well, that's something to think about. Or perhaps overthink.
Here's the reference:
Buia, Eric , Rachel Rodgersb, Henri Chabrolb, Philippe Birmesa and Laurent Schmitta. (2010) Is Anakin Skywalker suffering from borderline personality disorder? Psychiatry Research: published online. (DOI: 10.1016/j.psychres.2009.03.031)
Tuesday, June 15, 2010
A new study at the University of Leicester is looking at telomeres and how their length, particularly shortening, is controlled. Espcially as it relates to ageing and the development of cancer.
(1) Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the ends.
(2) A method in which information is copied from one telomere to another (not well understood)
The scientists in this study say that one of these methods must be activated during cancer development, and they are studying the ways that changes in the structure of DNA may control this shortening process.
This is a study that is in its early stages and so I don't have a reference for you, just a write-up in Science Daily, but its an interesting story that should get you thinking about understanding this relatively mysterious part of our DNA.
Here's the story:
They have a promiscuous mating system in which females mate with all the male members of the group. Females typically remain within their natal groups while males often disperse from these groups. This dispersal behavior in the males is critical for gene flow and the reproductive success of individual males. Every 2 years a female will give birth to a single offspring after a 165 day gestation period, and then the infants will cling to their mothers starting immediately after birth. These young primates are well-developed and will stay and nurse from their mothers for about a year. Male macaques are known to tend to a single young macaque, grooming protecting, and playing with the youngster. After all, with this type of mating system any male could potentially be the father of an infant, so it benefits a male to care for young. Males will establish hierarchies, hierarchies that change with the age of the males and the males that leave or enter the troop.
A new paper in Animal Behaviour describes how male Barbary macaques use infants as “costly social tools.” The researchers noticed that after an infant was born a male would slowly approach the mother and then seize the infant. The infant-toting male would then approach other males in the group, and non-infant-toting males would not interact. The males would hold infants for hours at a time, occasionally taking them back to their mothers for feedings. By using behavioral observations, social network analysis, and measures of fecal glucocorticoid metabolites (indicator of physiological stress) and comparing these to various seasons (spring birth season and autumn season) the authors were able to tease apart some of these male social behaviors. The hypothesis was that the infants would calm the males. However, analysis of hormone levels showed that stress hormones increased, suggesting that the males carried the infants to show that they could handle the pressure. Social network analysis showed that those males who carried infants was not related to rank, and that infant-carriers had stronger ties with other males when compared with non-infant-carriers.
Who knew that males macaques were such suckers for babies? I guess those furry, pink, wrinkly faces are kinda cute.
Here's the paper:
Henkela, Stefanie, Michael Heistermannb and Julia Fischer (2010) Infants as costly social tools in male Barbary macaque networks. Animal Behaviour: 79 (6), 1199-1204. (DOI: 10.1016/j.anbehav.2010.02.005)
and here's a great article in The New York Times:
"This direct blue laser diode is the result of the evolution of laser technology. Less than one year ago, this laser would have cost thousands of dollars to build. Don’t let the Arctic name fool you, this laser possesses the most burning capabilities of any portable laser in existence. That’s why it’s also the most dangerous laser ever created."So its a laser and not a lightsaber. But again, if you are making a portable laser why not make it look like a lightsaber?
"Warning: Extremely dangerous is an understatement to the power of 1W of laser power. It will blind permanently and instantly and set fire quickly to skin and other body parts, use with extreme caution and only when using the included eye protection. Customers will be required to completely read and agree to our Class IV Laser Hazard Acknowledgment Form."
Here are you links:
Monday, June 14, 2010
They checked the site again 4 years later and found that 40% of the transplanted coral had survived, even after a large storm and 2 coral bleaching events, some even growing large enough (1,450 cm^2 in area) to become sexually mature. The experiment also showed that fixing the coral to the seabed was an overall better method, allowing for more coral growth, than leaving the fragments free.
This method is simple, cheap, and effective if somewhat labor intensive. As such, it is probably not feasible on a large scale, but it could be implemented locally to restore areas affected by storms, pollution, coral bleaching, overfishing, etc.
Here's the article:
Forrester. G, et al. (2010) Evaluating Methods for Transplanting Endangered Elkhorn Corals in the Virgin Islands. Restoration Ecology: published online. (DOI: 10.1111/j.1526-100X.2010.00664.x)
(image from wildlifeflorida.com)
Thursday, June 10, 2010
The researchers broke things down into 2 studies. The first looked at variations in the gait between women at high and low conception probabilities. They conducted a motion capture study, recording the kinematics of their walking patterns. They repeated this procedure during the late follicular stage and the luteal stage with the women who were not using hormonal contraception. They found that there were significant differences in the walks of women at "high fertility risk" (naturally cycling and late follicular stage) and naturally cycling women at "low fertility risk," with no differences between hormonal birth control groups and high fertility risk groups. They speculate that these differences may be related to "fluctuations in personality dimensions" in women not on hormonal birth control like extroversion and agreeableness. I suppose if you are pissed off at the world then you have an angry walk. Grr.
In Study 2 the researchers asked men to rate the attractiveness of the walks. The men were not told the hormonal states of the women, just that they were rating women (point-light walkers of women) for attractiveness. They found that men were significantly more likely to rate women not using hormonal birth control as more attractive in their luteal phase. So men are judging naturally cycling women to be more attractive at a stage of low pregnancy probability. Seems a bit evolutionarily backwards, right? The authors speculate that this is a defense mechanism against sexual assault - broadly (and from far away) advertise that you are attractive when you are not actually fertile. Other studies show that other changes (body odor, facial attractiveness, etc.) increase in fertile times. The authors propose that these are more specific, closer cues that women share with men they are actually interested in.
How about a study about the walks of women who study the walks of women?
Provost Meghan P., Vernon L. Quinsey, and Nikolaus F. Troje. (2010) Differences in gait across the menstrual cycle and their attractiveness to men. Archives of Sexual Behavior: 37(4), 598-604. (DOI: 10.1007/s10508-007-9219-7)
(images from ovulation-calculator.com and examiner.com respectively)
A new paper in Nature takes a look at the brown algal genome to understand the evolution of multicellularity and photosynthesis. Researchers sequenced the genome of Ectocarpus siliculosus, a large brown seaweed that occurs along temperate latitude coastlines. In their paper they report on the 214 million base pair genome sequence.
They found that the E. siliculosus genome includes several features that have evolved for surviving in hostile shoreline environments that vary in light intensity, temperature, salinity and wave action. The researchers found a light harvesting complex (LHC), 53 loci including a cluster of 11 genes with highest similarity to the LI818 family of light-stress related LHCs. Also, the genome is predicted to encode a light-independent protochlorophyllide reductase (DPOR). This allows for the synthesis of chlorophyll under dim light. Together LHC and DPOR allow for survival in environments with highly varying light conditions. The genome encodes 21 putative dehalogenases and two haloalkane dehalogenases that may serve to protect the alge against halogenated compounds produced by kelps as defence molecules. This allows the brown algae to grow epiphytically on these organisms. The cell walls contain alginates and fucans, polysaccharides with properties that help in the resistance to mechanical stress and protection from predators.
The researchers also predicted the pattern of loss and gain of gene families during the evolution of a broad range of eukaryotes. A comparison of genomes showed that the major eukaryotic groups "have retained distinct but overlapping sets of genes since their evolution from a common ancestor, with new gene families evolving independently in each lineage. On average, lineages that have given rise to multicellular organisms have lost fewer gene families and evolved more new gene families than unicellular lineages. However, we were not able to detect any significant, common trends, such as a tendency for the multicellular lineages to gain families belonging to particular functional (gene ontology) groups." They found many genes for kinases, transporter and transcription factors, that are also commonly found in land plants. They suspect that these kinases play a key role in the origin of multicellular organisms. These data also relate to the idea that brown algae arose from the fusion of green alga and red alga as a high proportion of the genes that are characteristic of green algae, including the kinases and transporters typical of land plants, were found in the brown alga.
Monday, June 7, 2010
As of today the "Diet Coke + Mentos" video is at almost at 12 million hits and "The Coke Zero & Mentos Rocket Car" video has 2 million hits on YouTube (above). Not to mention a host of other videos on the same topic. So what's this all about, scientifically speaking?
Well, Coke and Mentos have a physical reaction. The nucleation sites in the pitted surface of the Mentos candy allows for the rapid formation of bubbles. The gelatin and gum arabic found in Mentos help to break the surface tension, allowing the rapidly forming bubbles to more rapidly form. When the candy sinks to the bottom of the Coke bottle the pressure from the forming bubbles/gas pushes the liquid up at a high rate.
A couple of years ago a paper was published in the American Journal of Physics looking at this physical reaction. They took two varieties of Mentos - fruit and mint - and scanned them with an electron microscope to look at the nucleation. They tested nucleation surfaces using the fruit Mentos, mint Mentos, liquid gum arabic, a mixture of Dawn Dishwashing liquid and water, table salt, rock salt, playground sand, Wint-o-Green Lifesavers, a mixture of baking soda and water, and molecular sieve beads. They observed these candy reactions in Coco-Cola Classic, Diet Coke, Caffeine Free Diet Coke Diet Coke, Caffeine Free Coca-Cola Classic, seltzer water, seltzer water with potassium benzoate added, seltzer water with aspartame added, tonic water, and diet tonic water. There were also temperature dependent trials where bottles were either refrigerated, heated, or kept at room temperature.
The results showed that drinks containing aspartame (a sweetener) and potassium benzoate (a preservative) to be more explosive than unsweetened drinks and drinks sweetened with sugar or corn syrup. This is probably due to a reduction in the work required for bubble formation. They found that the best nucleation sites were on the Mentos (both kinds) and that Mentos had a quick fall time which increased the number of bubbles coming from the bottom of the bottle, making it more explosive. Also, warmer Coke was found to have a larger explosion (due to Henry's Law).
So you want a big explosion? Place a Mentos with a lot of surface roughness in a diet Coke that has been heated.
Here's the article:
Coffey, T. (2008). Diet Coke and Mentos: What is really behind this physical reaction? American Journal of Physics: 76(6), 551-557. (DOI: 10.1119/1.2888546)
"Episode 57: Mentos and Soda" of Mythbusters on the Discovery Channel (first aired August 9, 2006)
Eichler, Jack F., Heather Patrick, Brenda Harmon, and Janet Coonce. (2007) Mentos and the scientific method: A sweet combination. Journal of Chemical Education: 84(7), 1120–1123. (DOI: 10.1021/ed084p1120))
In the 1980's S. planifrons was a common sight among the fore-reef terraces throughout the Caribbean, an abundant habitat at that time. It was thought that these fish were not at carrying capacity and recruitment-limited. However, with the decline of Acropora species, a decline caused or exacerbated by climate change, diseases, hurricanes, pollution and overfishing, this view is changing. Acropora are fast growing species and are thought to have held their own against damselfish, a trait that other coral species haven't exhibited, and with the decline in their populations other corals are feeling the strain.
Basically, the damselfish are not finding their optimal or preferred habitat - a habitat that can withstand herbivory by the fish. So they are looking for acceptable alternatives, slow-growing coral heads (especially the Montastraea annularis species complex) , and are eating them to death. This is a change that is killing many coral heads across the Caribbean, a change that could take hundreds of years to recover from. And even the fish themselves are limited by habitat and are also showing a decline. A likely course of action to help fix the problem would be to conserve staghorn corals, conserving fish stocks, and restoring coral (mainly staghorns) populations.
Here's the article:
Precht WF, Aronson RB, Moody RM, Kaufman L. (2010) Changing Patterns of Microhabitat Utilization by the Threespot Damselfish, Stegastes planifrons, on Caribbean Reefs. PLoS ONE: 5(5), e10835. (DOI: 10.1371/journal.pone.0010835)
Sunday, June 6, 2010
Friday, June 4, 2010
Thursday, June 3, 2010