Today’s headlines
For toilet museum, a final flush is avoided (The Boston Globe)
Bug foggers cause house explosion (The Galveston County Daily News)
Woman said she killed mom to go to jail, 'just read books' (Rocky Mountain News)
This is great news. Maybe Los Bravos will get back together
Blacker Than Black: Darkest Manmade Material Ever Made
ScienceDaily (Jan. 23, 2008) — Researchers at Rensselaer Polytechnic Institute and Rice University have created the darkest material ever made by man. The material, a thin coating comprised of low-density arrays of loosely vertically-aligned carbon nanotubes, absorbs more than 99.9 percent of light and one day could be used to boost the effectiveness and efficiency of solar energy conversion, infrared sensors, and other devices. The researchers who developed the material have applied for a Guinness World Record for their efforts.
"It is a fascinating technology, and this discovery will allow us to increase the absorption efficiency of light as well as the overall radiation-to-electricity efficiency of solar energy conservation," said Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation, who led the research project. "The key to this discovery was finding how to create a long, extremely porous vertically-aligned carbon nanotube array with certain surface randomness, therefore minimizing reflection and maximizing absorption simultaneously."
All materials, from paper to water, air, or plastic, reflect some amount of light. Scientists have long envisioned an ideal black material that absorbs all the colors of light while reflecting no light. So far they have been unsuccessful in engineering a material with a total reflectance of zero.
The total reflectance of conventional black paint, for example, is between 5 and 10 percent. The darkest manmade material, prior to the discovery by Lin's group, boasted a total reflectance of 0.16 percent to 0.18 percent.
Lin's team created a coating of low-density, vertically aligned carbon nanotube arrays that are engineered to have an extremely low index of refraction and the appropriate surface randomness, further reducing its reflectivity. The end result was a material with a total reflective index of 0.045 percent -- more than three times darker than the previous record, which used a film deposition of nickel-phosphorous alloy.
"The loosely-packed forest of carbon nanotubes, which is full of nanoscale gaps and holes to collect and trap light, is what gives this material its unique properties," Lin said. "Such a nanotube array not only reflects light weakly, but also absorbs light strongly. These combined features make it an ideal candidate for one day realizing a super black object."
"The low-density aligned nanotube sample makes an ideal candidate for creating such a super dark material because it allows one to engineer the optical properties by controlling the dimensions and periodicities of the nanotubes," said Pulickel Ajayan, the Anderson Professor of Engineering at Rice University in Houston, who worked on the project when he was a member of the Rensselaer faculty.
The research team tested the array over a broad range of visible wavelengths of light, and showed that the nanotube array's total reflectance remains constant.
"It's also interesting to note that the reflectance of our nanotube array is two orders of magnitude lower than that of the glassy carbon, which is remarkable because both samples are made up of the same element -- carbon," said Lin.
This discovery could lead to applications in areas such as solar energy conversion, thermalphotovoltaic electricity generation, infrared detection, and astronomical observation.
Other researchers contributing to this project and listed authors of the paper include Rensselaer physics graduate student Zu-Po Yang; Rice postdoctoral research associate Lijie Ci; and Rensselaer senior research scientist James Bur.
The project was funded by the U.S. Department of Energy's Office of Basic Energy Sciences and the Focus Center New York for Interconnects.
Lin's research was conducted as part of the Future Chips Constellation at Rensselaer, which focuses on innovations in materials and devices, in solid state and smart lighting, and applications such as sensing, communications, and biotechnology. A new concept in academia, Rensselaer constellations are led by outstanding faculty in fields of strategic importance. Each constellation is focused on a specific research area and comprises a multidisciplinary mix of senior and junior faculty, as well as postdoctoral researchers and graduate students.
Somehow, the words lizard and gender shouldn’t be used together
Global warming might affect lizard gender
AMES, Iowa, Jan. 23 (UPI) -- A U.S. researcher has discovered egg incubation temperatures have an affect on Australian reptiles.
Iowa State University biologist Dan Warner spent four years in Australia studying the "jacky dragon" lizard to discover if egg incubation temperature and gender affects the viability of the lizards.
In mammals, gender is determined by the chromosomes an embryo inherits from the father. But in some reptiles, gender is determined by temperatures the embryos experience.
Warner tracked male and female lizards born at different temperatures and measured how well they reproduced. In the "jacky dragon," males are born at around 77 to 86 degrees Fahrenheit, while females are born at temperatures both above and below that range. Because some temperatures only produce one gender, Warner had to reverse the sex of some of the embryos using hormones.
Warner discovered "jacky dragons" thrive when they are born at the right temperatures for their gender. He found both males and females reproduce more when exposed to the correct egg incubation temperatures.
He said his findings might have grave consequences for the species if temperatures increase in the parts of Australia where the lizards live.
The study appears in the journal Nature.
It’s dark. We’re sad. No one loves us. Got any ice cream?
Seasonal Weight Changes Linked To Metabolic Syndrome
ScienceDaily (Jan. 23, 2008) — Seasonal changes in weight increase the risk for metabolic syndrome, a group of scientists from National Public Health Institute, Helsinki, Finland.
This finding was based on analysis of 8,028 individuals, representative of the general population aged over 30, who attended a nationwide health examination survey.
According to the current study, individuals with metabolic syndrome have more seasonal changes in their mood and behavior. The study concludes that the seasonal changes in weight in particular are linked to metabolic syndrome.
With people having the 'winter blues' the risk of metabolic syndrome is heightened by 56 per cent. The negative effect of the seasonal changes equals to the protective effect against metabolic syndrome gained with regular physical exercise.
Because of easy assessment the scoring of seasonal changes in weight might be taken as a routine part of health status examination in persons being at risk of or currently having metabolic syndrome. If there were these changes, treatment options including scheduled exposures to light and regular physical exercise need to be considered.
"Disruption of circadian rhythms has been implicated in the pathogenesis of metabolic disorders. Our results give support to the hypothesized links between the metabolic and circadian cycles generated and guided by the circadian clock", says Timo Partonen, MD, academy research fellow of the group. "Our findings herein now extend these links to include relationships between the metabolic and seasonal fluctuations."
The current findings now suggest that abnormalities in the circadian clockwork predispose to seasonal changes in weight and to metabolic syndrome. This means that the circadian clockwork may well be a key to public health.
Obesity is an increasing problem concerning public health. High caloric intake or low physical exercise for example may lead not only to obesity but also to hypertension, insulin resistance and abnormal circulating lipid levels. These abnormalities tend to coincide and contribute to the term metabolic syndrome.
They laugh alike, they walk alike, At times they even talk alike—
You can lose your mind
Genome Scan Shows Polynesians Have Little Genetic Relationship To Melanesians
ScienceDaily (Jan. 23, 2008) — The origins and current genetic relationships of Pacific Islanders have generated interest and controversy for many decades. Now, a new comprehensive genetic study of almost 1,000 individuals has revealed that Polynesians and Micronesians have almost no genetic relation to Melanesians, and that groups that live in the islands of Melanesia are remarkably diverse.
The researchers analyzed more than 800 genetic markers (highly informative microsatellites) in nearly 1,000 individuals from 41 Pacific populations, as opposed to prior small-scale mitochondrial DNA or Y chromosome studies, which had produced conflicting results.
"The first settlers of Australia, New Guinea, and the large islands just to the east arrived between 50,000 and 30,000 years ago, when Neanderthals still roamed Europe," says Jonathan Friedlaender, professor emeritus of anthropology at Temple and the study's lead author. "These small groups were isolated and became extremely diverse during the following tens of thousands of years. Then, a little more than 3,000 years ago, the ancestors of the Polynesians and Micronesians, with their excellent sailing outrigger canoes, appeared in the islands of Melanesia, and during the following centuries settled the islands in the vast unknown regions of the central and eastern Pacific.
"Over the last 20 years there have been many hypotheses concerning where the ancestors of the Polynesians came from in Asia, how long it took them to develop their special seafaring abilities in Island Melanesia, and how much they interacted with the native Melanesian peoples there before they commenced their remarkable Diaspora across the unexplored islands in the Pacific," he adds.
According to Friedlaender, one scenario called the 'fast train hypothesis,' which is supported by the mitochondrial evidence, suggests that ancestors of the Polynesians originated in Taiwan, moved through Indonesia to Island Melanesia, and then out into the unknown islands of the Pacific without having any significant contact with the Island Melanesians along the way.
A counter argument called 'slow boat hypothesis,' which the Y chromosome evidence supports, suggests that the ancestors of the Polynesians were primarily Melanesians, and that there was very little Asian or Taiwanese influence. A third position, called the "entangled bank hypothesis," suggests these ancient migrations simply can't be accurately reconstructed by looking at the genetics of today's populations, even in the context of the available archaeological evidence.
In their paper, the researchers state that their analysis is consistent with the scenario that the ancestors of Polynesians moved through Island Melanesia relatively rapidly and only intermixed to a very modest degree with the indigenous populations there.
"Our genetic analysis establishes that the Polynesians' and Micronesians' closest relationships are to Taiwan Aborigines and East Asians," says Friedlaender. "Some groups in Island Melanesia who speak languages related to Polynesian, called Austronesian or Oceanic languages, do show a small Polynesian genetic contribution, but it is very minor -- never more than 20 percent.
"There clearly was a lot of cultural and language influence that occurred, but the amount of genetic exchange between the groups along the way was remarkably low," he says. "From the genetic perspective, if the ancestral train from the Taiwan vicinity to Polynesia wasn't an express, very few passengers climbed aboard or got off along the way."
Friedlaender adds that this study also confirms and expands their findings from previous studies about the genetic diversity of Island Melanesians--among the most genetically diverse people on the planet, showing further that their diversity is neatly organized by island, island size, topography and language families.
Where’s that Kon Tiki guy when you need him? We bet he could sort this out.
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