Mojo: The libido. The life force. The essence. The right stuff. What the French call a certain… I don’t know what.
Mojoceratops was discovered when Nicholas Longrich from Yale University was looking at existing fossils from American Museum of Natural History in New York. They had been classified as another species, Chasmosaurus, but Nicholas believed [...]... Read more »
Longrich, Nicholas R. (2010) Mojoceratops perifania, A New Chasmosaurine Ceratopsid from the Late Campanian of Western Canada. Journal of Paleontology, 84(4), 681-694. info:/
This question came in from @holabendez for Science Week. What causes a double rainbow? The question is inspired by, in my opinion, the best youtube video since Keyboard Cat met Hall and Oates. Check out the Double Rainbow video below - if I'm this happy for just one day in my life, it will have been a happy life:
And now you'd better check out the Double Rainbow Song....
Rainbows are the result of the reflection and refraction of light by water droplets. They can be seen when there are water droplets in the air in front of you and sunlight shining from behind you at a low angle. You can also see them when looking at a sprinkler or hose, and sometimes they are created by the moon. But before we jump into the optics involved, let's review some high school physics.
White light and refraction:
White light from the Sun is made up of all the various colours of visible light. Each of these colours has a different wavelength - red light (at one edge of the rainbow) has a wavelength of ~650 nm, whilst violet light (at the other edge) has a wavelength of ~400 nm.
When light travels from one medium (say air) to another (water), it changes speed, and if the light enters at an angle, it will bend. This is known as refraction. Shorter wavelength light (such as violet) refracts more than longer wavelength light (such as red). You can see white light splitting into its constituent colours in the image to the right.
NB: The Sun may not look white from here on Earth (it looks yellow), but if you were to observe it from space, it would look white. This is because the Earth's atmosphere scatters shorter wavelength light (like violet) more than longer wavelength light (red). See our story on the dust storm that turned Sydney red for more discussion of atmospheric scattering.
Rainbows result from a combination of reflection and refraction. The pictures below show the optics of how this works. The grey circles are water droplets. White light enters the droplet and is refracted, then reflected off the back of the droplet, before leaving the drop split into its constituent colours, again refracted. Some light will travel through the droplet - the reflection is not 100%. Red light leaves the droplet at a slightly higher angle than violet - this angle is independent of the size of the drop, but does depend on its refractive index. Seawater has a higher refractive index than rain water, so the radius of a rainbow in sea spray is smaller than a rainbow in the sky. The following picture shows the paths of red and violet light in the production of a rainbow - the other colours of a rainbow (for example green) travel somewhere between the two extremes.
When you see a rainbow, you are seeing light that has been refracted and reflected through water droplets, however the red colour does not come from exactly the same droplets of water as the violet colour. If you were able to isolate one particular water drop that produced some of the red colour you saw, the violet light from this drop would not meet your eyes - it would travel over your head. The following picture shows that multiple water droplets contribute to the colours you see - this is why red is the top colour in the rainbow.
In the immortal words of the above youtube video, a double rainbow, Oh My God, what does this mean? It means interesting optics. A secondary rainbow is produced when there is one extra reflection of light within the water drop. As some light is lost each time it hits the edge of the drop, the secondary rainbow is fainter than the first. It appears higher in the sky because the light exits the drop at a larger angle (50-53 degrees) than the primary rainbow (40-42 degrees).
The colours in the secondary rainbow are in reversed order to the primary rainbow.
The following picture shows how the rainbow appears in the sky with regards to the Sun and the observer. The same picture also makes sense for the secondary rainbow, however it would appear at a larger angle, and therefore could also appear later in the day when the Sun is higher in the sky - it would also have the colours reversed. If the Sun is higher than 42° (or 53° for the secondary), the rainbow is below the horizon and usually cannot be seen.
The reason that the rainbow is circular is that this is the only shape that reflects the light back to your eyes at 42° (or 53°) - water droplets below and above (or to the left and right) of the rainbow do not reflect the light to your eyes. What this means is that everyone sees a different rainbow. If you are looking at a rainbow and walk to a new position, the light you see in the new spot will have been reflected by different water droplets to the light you saw in the first spot. This is also why there is no pot of gold at the end of the rainbow - there is actually no end of the rainbow. A rainbow does not actually exist at a particular location in the sky - it all depends on your location and the position of the Sun.
It is possible to see a completely circular rainbow, but only if you are in a plane above the ground. In this case, you could look down and possibly see a rainbow whose centre is the shadow the plane. Climbing a mountain may not help you see a more complete rainbow as the mountain itself would cast a shadow, blocking the light which would cause the rainbow.
So even though a "double rainbow all the way across the sky" may seem a mystical experience, it's really just physics!
G., T. (1938). Descartes' Discourse on Method Nature, 141 (3574), 769-769 DOI: 10.1038/141769c0
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In 2009, I contributed a chapter about the social inclusion of migrants in Australia to an edited book about immigration policy published in Japanese in Japan. The book is doing well – a second edition has just been published – … Continue reading →... Read more »
Choi, P. (2010) 'Weep for Chinese university': a case study of English hegemony and academic capitalism in higher education in Hong Kong. Journal of Education Policy, 25(2), 233-252. DOI: 10.1080/02680930903443886
Is it a wolf? No. A coyote? No. A mixture of the two? Oh, yes. Northeastern wild canids have been leading biologists on a wild goose chase recently, as science scrambles to catch up with just what, exactly, Mother Nature has been cooking up in Massachusetts. Reports of extra large eastern coyotes have been rolling [...]... Read more »
Jon Way, Linda Rutledge, Tyler Wheeldon, & Bradley N. White. (2010) Genetic characterization of eastern coyotes in eastern Massachussets. Northeastern Naturalist. info:/
When animals are made to feel anxious and frustrated, they often turn to displacement activities - goals which may be irrelevant, but which they can at least achieve. Rats may run so eagerly on wheel that they starve themselves to death. Dogs may lick themselves so repetitively that they develop skin lesions. But what do humans do?
One thing we can do, according to new research by Ian McGregor and colleagues at York University, Toronto, Canada, is to become more fervent in our pursuit of cherished ideals. When people are frustrated in their attempts to achieve concrete, real-world goals, abstract ideologies provide a readily achievable displacement goal.
To test this theory, they ran a series of studies on undergrads. Basically, the setup was to make them anxious about failure, either by asking them to complete an impossible task or to recount a troubled relationship they had. Then they measured various religious attitudes, including religious zealotry.
You can see an example of what happened in the figure. In this particular study they asked participants to think of a goal they had in their personal lives, and then to rate how determined they were to achieve it, how in control they felt, and how important it was. The ones who rated highly were considered to be 'empowered'.
It turns out that that the empowered people did not change in zealotry when placed in a anxiety-inducing situation, whereas the unempowered people became much more zealous. Now, this wasn't because the empowered people felt less anxious. In fact, they felt more anxious. But they didn't turn to religion as a displacement.
In other studies, they also found that people did not become more superstitious in general. What's more, the effect was strongest in people who thought of uncertainty as nerve racking and, intriguingly, in those spirited individuals who believe in taking action to deal with problems.
They also found hints that this effect is stronger in those who believe in the three monotheisms, rather than Eastern religions (or atheists, of course), and suggest that this might be why religious extremism is more common in the West:
In Western religion, the allure of ideological zeal may be that it can reliably activate the resilience of transcendent approach motivation when temporal goals are frustrated. Unfortunately, religious extremists in the West have a long history of blood on their hands. The same empowering approach motivation that makes one soar may also obscure one’s view of others’ perspectives and facilitate ideological cruelty in the guise of noble cause. Such self-empowered, anger-related, and risk-immune RAM processes, in combination with scripture that advocates aggression toward others, may inflame religious violence in the West.Now, this research is pretty preliminary. Other research has found that anxiety and uncertainly increases belief in a controlling God - but this study found no such effect. Of course, it's possible that both effects (handing over control to a powerful God, or displacing the frustrated goal with an achievable, nontangible one) could both occur in different in people with personalities and in different situations. Then too, there is another theory (Terror Management), which claims that people cling to their 'in-group' cultural traditions when threatened.
But this research is encouraging because, although we've long known intuitively that people turn to religion when they feel stressed and unhappy. The question is how and why. Now, at least, we have three good theories about what is going on here. Only further research is going to tease them apart!
McGregor I, Nash K, & Prentice M (2010). Reactive approach motivation (RAM) for religion. Journal of personality and social psychology, 99 (1), 148-61 PMID: 20565192
This article by Tom Rees was first published on Epiphenom. It is licensed under Creative Commons.
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Paul, the ‘Psychic’ octopus who can apparently predict* World Cup football match results, has inspired a lot of silliness attracted a lot of media attention recently. But can any other marine organisms see into the future? Sea snakes of the genus Laticauda (Fig 1.) are not entirely aquatic – not only must they regularly return [...]... Read more »
Y.-L. Liu, H. B. Lillywhite, and M.-C. Tu1. (2010) Sea snakes anticipate tropical cyclone. Marine Biology. info:/
When I took my GCSE science exams, sometimes the questions were set in the context of an experiment. John and Sarah are investigating the effect of temperature on the rate of photosynthesis. or A physicist was investigating this or that...... Read more »
Good JJ, Woodzicka JA, & Wingfield LC. (2010) The effects of gender stereotypic and counter-stereotypic textbook images on science performance. The Journal of social psychology, 150(2), 132-47. PMID: 20397590
Chan and Hayashi (2010) think that Japanese men might be badly afflicted by gender role conflict, only to happily discover that it's nothing that can't be fixed by a bit of cognitive therapy.... Read more »
Chan, R.K.H., & Hayashi, K. (2010) Gender Roles and Help-Seeking Behaviour: Promoting Professional Help among Japanese Men. Journal of Social Work, 10(3), 243-262. info:/
One of those really cool and useful "evolution stories" gets verified and illuminated by actual research. And blogging!
Read the rest of this post... | Read the comments on this post...... Read more »
Baldwin, W. P. (1946) Clam catches oyster-catcher. The Auk, 589-589. info:other/
In the first of a likely irregular column on politics and evidence based policy, Keir Liddle looks at proposals to introduce minimum pricing for alcohol, querying what effects it may have and whether the policy seems justified.... Read more »
Purshouse, R., Meier, P., Brennan, A., Taylor, K., & Rafia, R. (2010) Estimated effect of alcohol pricing policies on health and health economic outcomes in England: an epidemiological model. The Lancet, 375(9723), 1355-1364. DOI: 10.1016/S0140-6736(10)60058-X
Another one from the annals of weird deaths. Believe it or don't, wading birds sometimes get their toes or bill-tips caught in bivalve shells, they remain trapped, and they then drown when the tide comes in. Here is rare photographic evidence of this behaviour...
Read the rest of this post... | Read the comments on this post...... Read more »
Baldwin, W. P. (1946) Clam catches oyster-catcher. The Auk, 589-589. info:/
In his 2009 paper Brian Tomlin analyzes strategies to mitigate disruption risks in a three echelon supply chain.
Focus in his research is a single company, with its suppliers and customers. The objective is to maximize expected utility, while demand and supply are uncertain. There are two products available which can be used as substitutes. The time horizon for the decision maker is one season where the products can be sold.
Three different sourcing structures are considered.
Different sourcing structures (Source: Tomlin 2009)
Continue reading "Disruption-Management Strategies for Short Life-Cycle Products"
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Tomlin, B. (2009) Disruption-management strategies for short life-cycle products. Naval Research Logistics, 56(4), 318-347. DOI: 10.1002/nav.20344
A low-carbohydrate Mediterranean diet improved HDL cholesterol levels and glucose control better than either the standard Mediterranean diet or American Diabetes Association diet, according to Israeli researchers reporting earlier this year.
Prior studies suggest that diets rich in monounsaturated fatty acids (olive oil, for example) elevate HDL cholesterol and reduce LDL cholestrol and triglycerides in type [...]... Read more »
Elhayany, A., Lustman, A., Abel, R., Attal-Singer, J., & Vinker, S. (2010) A low carbohydrate Mediterranean diet improves cardiovascular risk factors and diabetes control among overweight patients with type 2 diabetes mellitus: a 1-year prospective randomized intervention study. Diabetes, Obesity and Metabolism, 12(3), 204-209. DOI: 10.1111/j.1463-1326.2009.01151.x
In my recent quest to find new, cutting-edge research on cephalopods, I've come across some neat stuff (check out this post on the perception of polarized light by cuttlefish - it's one of my favorite new cephalopod research topics!) The study I'll review here is outside of my field of relative expertise, but it's so neat and so new that I couldn't resist writing about it. It's good to step out of one's comfort zone every once in a while, right?An international team of researchers hailing from Norway, Australia, and Germany has published a study on the venom of Antarctic octopods (more accurately, it is being published, though it hasn't hit the presses yet.) The team investigated the biochemical properties of extracts from the salivary gland of four Antarctica octopus species and wrote up their results in Venom on ice: First insights into Antarctic octopus venoms (2010).Here is their image of the posterior salivary glands of an octopus, from which the authors collected all of their specimens:These glands produce a variety of compounds, notably venom and digestive enzymes. The venom of temperate-water octopuses has been studied in the past. Never before, however, has venom been studied in an octopus that lives in below-freezing temperatures, conditions under which the enzymes in most venoms work very poorly if at all. To begin to understand the role of venoms in the lives of Antarctic octopuses, the team collected and tested venom from four octopus species collected off the Antarctic shore: Adelieledone polymorpha, Megaleledone setebos, Pareledone aequipapillae, and Pareledone turqueti. Here are images of some of their specimens:Cute, aren't they? Octopods always are! Anyways, back to the biochemical assays.First, the authors tested the extracts for alkaline phosphatase (ALP) activity. ALP is an enzyme that is in spider and snake venom that is thought to help immobilize prey items. Second, they tested for Acetylcholinesterase (AChE) activity. AChE breaks down acetylcholine, a neurotransmitter, potentially acting as a toxin by disrupting neuromuscular function. Third, the extracts were tested for general proteolytic activity using casein. Fourth, an assay for secreted phospholipase A2 (sPLA2) was performed. sPLA2 is found in cone snail and snake venome, and contributes to the effects of venoms in a variety of ways. Finally, the researches assessed whether the venoms showed haemolytic activity, which is a common marker of the general toxic activity of venoms. Taken together, these results should begin to characterize the putative venom of each octopus species. After all of this, the researchers reviewed what is known about the morphology of the mouthparts of the octopuses, as well as their feeding habits, and tried to relate these to their biochemical findings.Whew.So, after all of that, what did they find? Here are their results(takes another deep breath):Venom from all of the species had some ALP activity. Interestingly, however, when ALP activity was tested at 0 Celsius and at 37 Celsius, venom from 3 species of octopus (A. polymorpha, M. setebos, and P. turqueti) had higher ALP activity at the lower temperature! This is a significant finding because it suggests some sort of modification of the proteins responsible for this activity to function optimally at a lower temperature. This lends some weight to the theory that the use of venom has been important enough to the survival of Antarctic octopus species that they have evolved enzymes to work under conditions where most enzymatic toxins would not. In the other tests, an essentially similar pattern of results were found, except for the AChA activity assay. Little AChA activity was found in any of the species, although the results of the assay were poor enough (that is, inconsistent) that they were not included in the paper. Interestingly enough, although all of the species had a few potentially functional toxins in their venom, most of them showed only weak haemolytic activity. Only one extract (from P. turqueti) showed strong haemolytic activity.The relation of venom activity to morphology and diet that the authors attempted to point out appears to be weak (or at least difficult to point out given their sample,) as it is mentioned that few clear venom-related adaptations in diet or anatomy were present in these octopus species. A. polymorpha is noted to have a very large salival gland and a narrow beak, which the authors suggest might be an adaptation associated with the use of venom as a primary means of catching prey (as opposed to having powerful jaws to physically overpower the prey.) This species feeds mostly on amphipods and polychaete worms, and so it's unclear why it would rely on venom to subdue such (relatively) easy going prey instead of retaining a more varied diet. In any case, though, this is one of those papers that, being exploratory, raises many more questions than it answers - that's the kind I like!What I find most interesting about this work is that it begs questions about the evolution of octopus venom. How quickly could the octopus populations move into cold water? Was this limited by the evolution of venom enzymes, or did that evolution occur after some quicker relocation of the species which left their warm-water-adapted enzymes useless? Did A. polymorpha's ancestors have a specialized diet before they became Antarctic, or is that only a successful feeding strategy in the Antarctic environment? The world may never know (although I hope we do, someday!)Thanks for reading!Undheim, E.A.B., et al. (2010). Venom on Ice: First insights into Antarctic octopus venoms Toxicon... Read more »
Undheim, E.A.B., et al. (2010) Venom on Ice: First insights into Antarctic octopus venoms. Toxicon. info:/
As Professor Farnsworth would say, shocking news everyone! A new experiment says that we’ve consistently been overestimating the size of protons by about 3 × 10^-14 millimeters, and the physicists who measured this discrepancy by tracking the motions of electrons’ much heavier siblings, are clutching their chests in fear that they might’ve broken a law [...]... Read more »
Randolf Pohl, Aldo Antognini, François Nez, Fernando D. Amaro, François Biraben, João M. R. Cardoso, Daniel S. Covita, Andreas Dax, Satish Dhawan, Luis M. P. Fernandes, Adolf Giesen, Thomas Graf, Theodor W. Hänsch, Paul Indelicato, Lucile Julien, Chen. (2010) The size of the proton. Nature, 466(8 July 2010), 213-216. info:/10.1038/nature09250
The normal distribution is the “norm” when applying statistics to data. It is simple to interpret, simple to predict, simple to optimize, convenient software-wise and analytically elegant. But in many applications, this modeling assumption may not be optimal. The first is that the normal distribution doesn’t have a zero bound. In ecology, the data is [...]... Read more »
LIMPERT, E., STAHEL, W., & ABBT, M. (2001) Log-normal Distributions across the Sciences: Keys and Clues. BioScience, 51(5), 341. DOI: 10.1641/0006-3568(2001)051[0341:LNDATS]2.0.CO;2
Researchers in this week's the Journal of Neuroscience reported that chromosomal make-up exerts a significant influences on habit-forming alcohol behaviors and amount consumed, arguing against a more traditional hypothesis that reproductive hormones drive alcohol-related behaviors. ... Read more »
Barker JM, Torregrossa MM, Arnold AP, & Taylor JR. (2010) Dissociation of genetic and hormonal influences on sex differences in alcoholism-related behaviors. The Journal of neuroscience : the official journal of the Society for Neuroscience, 30(27), 9140-4. PMID: 20610747
by Matt DiLeo in Biofortified
I’ve been meaning to tell this story for some time. It’s a good example of how not all biotechnology is genetic engineering. Traditional Breeding In trad breeding, the breeder/gardener simply crosses two parents that show great (and complementary) traits, grows up the offspring, selects the best and repeats. It’s effective, slow, labor intensive and limited by the perception of the breeder. Most traits are also very heavily impacted by the environment, so each new Continue reading...... Read more »
Bernardo, R., & Yu, J. (2007) Prospects for Genomewide Selection for Quantitative Traits in Maize. Crop Science, 1082-1090. DOI: 10.2135/cropsci2006.11.0690
Schaeffer LR. (2006) Strategy for applying genome-wide selection in dairy cattle. Journal of animal breeding and genetics , 123(4), 218-23. PMID: 16882088
Restoring coral reefs is a delicate business. Corals can bleach, become detached, or get hit by natural disasters. But using a fast-growing “weedy” species could improve the odds of success, researchers say.
A team tested the idea with Montipora digitata, a coral species that grows quickly and often produces new colonies by fragmenting. The researchers […] Read More »... Read more »
Shaish, L., Levy, G., Katzir, G., & B. Rinkevich. (2010) Employing a highly fragmented, weedy coral species in reef restoration. Ecological Engineering. info:/10.1016/j.ecoleng.2010.06.022
Friends, This is the third and final post in my series on the Fto gene. The appearance of a new an exciting paper will, of course, increase the probability of me emitting another Fto related post, but this is it for the time being. Fto is an exciting gene, however, so it likely won’t be [...]... Read more »
Fischer, J., Koch, L., Emmerling, C., Vierkotten, J., Peters, T., Brüning, J., & Rüther, U. (2009) Inactivation of the Fto gene protects from obesity. Nature, 458(7240), 894-898. DOI: 10.1038/nature07848
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