| |
posted to no-tag
by InquilineKea
on 2012-05-16 20:20:30
|
| |
Abstract
We describe the real-time movements of the last of the marine mega-vertebrate taxa to be satellite tracked – the giant manta ray (or devil fish, Manta birostris), the world's largest ray at over 6 m disc width. Almost nothing is known about manta ray movements and their environmental preferences, making them one of the least understood of the marine mega-vertebrates. Red listed by the International Union for the Conservation of Nature as ‘Vulnerable’ to extinction, manta rays are known to be ...
|
| |
|
| |
posted to no-tag
by InquilineKea
on 2012-03-25 00:39:58
Abstract
Various organisms (i.e., bacteria, fungi, plants and animals) within an ecosystem can synthesize and release into the environment certain longevity-extending small molecules. Here we hypothesize that these interspecies chemical signals can create xenohormetic, hormetic and cytostatic selective forces driving the ecosystemic evolution of longevity regulation mechanisms. In our hypothesis, following their release into the environment by one species of the organisms composing an ecosystem, such ...
|
| |
Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, No. 42. (20 October 2009), pp. 17787-17792, doi:10.1073/pnas.0902380106
by Kyle L. Hoehn, Adam B. Salmon, Cordula Hohnen-Behrens, et al.Nigel Turner, Andrew J. Hoy, Ghassan J. Maghzal, Roland Stocker, Holly Van Remmen, Edward W. Kraegen, Greg J. Cooney, Arlan R. Richardson, David E. James
Abstract
We know a great deal about the cellular response to starvation via AMPK, but less is known about the reaction to nutrient excess. Insulin resistance may be an appropriate response to nutrient excess, but the cellular sensors that link these parameters remain poorly defined. In the present study we provide evidence that mitochondrial superoxide production is a common feature of many different models of insulin ...
|
| |
Proceedings of the National Academy of Sciences of the United States of America, Vol. 105, No. 9. (4 March 2008), pp. 3438-3442, doi:10.1073/pnas.0705467105
Abstract
Rather than being a passive, haphazard process of wear and tear, lifespan can be modulated actively by components of the insulin/insulin-like growth factor I (IGFI) pathway in laboratory animals. Complete or partial loss-of-function mutations in genes encoding components of the insulin/IGFI pathway result in extension of life span in yeasts, worms, flies, and mice. This remarkable conservation throughout evolution suggests that altered signaling in this ...
|
| |
by Lilian Calderón-Garcidueñas, Anna C. Solt, Carlos Henríquez-Roldán, et al.Ricardo Torres-Jardón, Bryan Nuse, Lou Herritt, Rafael Villarreal-Calderón, Norma Osnaya, Ida Stone, Raquel García, Diane M. Brooks, Angelica González-Maciel, Rafael Reynoso-Robles, Ricardo Delgado-Chávez, William Reed
Abstract
Air pollution is a serious environmental problem. We investigated whether residency in cities with high air pollution is associated with neuroinflammation/neurodegeneration in healthy children and young adults who died suddenly. We measured mRNA cyclooxygenase-2, interleukin-1beta, and CD14 in target brain regions from low (n = 12) or highly exposed residents (n = 35) aged 25.1 +/- 1.5 years. Upregulation of cyclooxygenase-2, interleukin-1beta, and CD14 in ...
|
| |
posted to no-tag
by InquilineKea
on 2012-01-17 00:32:20
Abstract
The 2008 presidential election offers a unique opportunity to revisit the hypothesis that a divisive primary exacts a tolls on the party’s general election performance—neither party had a sitting president or vice president seeking the nomination, the Democratic nomination was contested all the way to the end, and advertising data provide a way to gauge both the intensity and tenor of the campaigns. In this article, we take advantage of these circumstances to distinguish between primaries that were competitive and those ...
|
| |
posted to no-tag
by InquilineKea
on 2012-01-05 22:41:43
Abstract
Most discussion of habitable planets has focused on Earth-like planets with globally abundant liquid water. For an "aqua planet" like Earth, the surface freezes if far from its sun, and the water vapor greenhouse effect runs away if too close. Here we show that "land planets" (desert worlds with limited surface water) have wider habitable zones than aqua planets. For planets at the inner edge of the habitable zone, a land planet has two advantages over an aqua planet: (i) the ...
|
| |
posted to no-tag
by InquilineKea
on 2012-01-04 21:25:52
|
| |
(19 Jan 2011)
Abstract
We study the possible existence of an electroweak star - a compact stellar-mass object whose central core temperature is higher than the electroweak symmetry restoration temperature. We found a solution to the Tolman-Oppenheimer-Volkoff equations describing such an object. The parameters of such a star are not substantially different from a neutron star - its mass is around 1.3 Solar masses while its radius is around 8 km. What is different is the existence of a small electroweak core. The source of energy in the core that can at ...
|
| |
(31 Oct 2011)
Abstract
The field of astronomy is starting to generate more data than can be managed, served and processed by current techniques. This paper has outlined practices for developing next-generation tools and techniques for surviving this data tsunami, including rigorous evaluation of new technologies, partnerships between astronomers and computer scientists, and training of scientists in high-end software engineering engineering skills. ...
|
| |
posted to no-tag
by InquilineKea
on 2011-10-26 21:51:00
|
| |
posted to no-tag
by InquilineKea
on 2011-10-26 21:50:47
|
| |
(20 Oct 2011)
posted to no-tag
by InquilineKea
on 2011-10-24 19:12:48
Abstract
M-stars comprise 80% of main-sequence stars, and so their planetary systems provide the best chance for finding habitable planets, i.e.: those with surface liquid water. We have modelled the broadband albedo or reflectivity of water ice and snow for simulated planetary surfaces orbiting two observed red dwarf stars (or M-stars) using spectrally resolved data of the Earth's cryosphere. The gradual reduction of the albedos of snow and ice at wavelengths greater than 1 ?m, combined with M-stars emitting a significant fraction of their radiation at these same longer ...
|
| |
Abstract
Alzheimer's disease (AD) is the most common cause of progressive cognitive decline and dementia in adults. While the amyloid cascade hypothesis of AD posits an initiating role for the ²-amyloid (A²) protein, there is limited understanding of why A² is deposited. A growing body of evidence based on in vitro, animal studies and human imaging work suggests that synaptic activity increases A², which is deposited preferentially in multimodal brain regions that show continuous levels of heightened activation and plasticity across the ...
|
| |
Abstract
One Nobel laureate reviews another's account of "The Beginner's Guide to Winning the Nobel Prize. A Life in Science.". ...
|
| |
(26 Nov 1994)
Abstract
In 1976 Stephen Hawking proposed that information may be lost from our universe as a pure quantum state collapses gravitationally into a black hole, which then evaporates completely into a mixed state of thermal radiation. Although this proposal is controversial, it is tempting to consider analogous processes that might occur in certain theories of consciousness. For example, one might postulate that independent degrees of freedom be ascribed to the mental world to help explain the feeling of a correlation between one's desires and one's choice of actions. If ...
|
| |
|
| |
posted to no-tag
by InquilineKea
on 2011-10-06 08:05:23
|
| |
posted to no-tag
by InquilineKea
on 2011-10-06 01:24:26
Abstract
Abstract Viable explanations for equable climates of the Cretaceous and early Cenozoic (from about 145 to 50 million years ago), especially for the above-freezing temperatures detected for high-latitude continental winters, have been a long-standing challenge. In this study, the authors suggest that enhanced and localized tropical convection, associated with a strengthened paleo?warm pool, may contribute toward high-latitude warming through the excitation of poleward-propagating Rossby waves. This warming takes place through the poleward heat flux and an overturning circulation that accompany the ...
|
| |
Abstract
The early Eocene "equable climate problem", i.e. warm extratropical annual mean and above-freezing winter temperatures evidenced by proxy records, has remained as one of the great unsolved problems in paleoclimate. Recent progress in modeling and in paleoclimate proxy development provides an opportunity to revisit this problem to ascertain if the current generation of models can reproduce the past climate features without extensive modification. Here we have compiled early Eocene terrestrial temperature data and compared with climate model results with a consistent ...
|
| |
posted to no-tag
by InquilineKea
on 2011-10-05 09:31:52
|
| |
posted to no-tag
by InquilineKea
on 2011-09-30 01:16:08
Abstract
While research has shown that religious individuals are perceived as being more moral than the nonreligious, the present studies suggest that these findings are affected by in-group bias. Participants low and high in religious fundamentalism (RF) were asked to form an impression of a target's moral and social dimensions. The target's religious identity was presented either explicitly (in Studies 1 and 2) or implicitly (Study 3). Participants high in RF consistently rated the religious target more favorably than the nonreligious target ...
|
| |
Abstract
To overcome the increasing resistance of pathogens to existing antibiotics the 10×'20 Initiative declared the urgent need for a global commitment to develop 10 new antimicrobial drugs by the year 2020. Naturally occurring animal antibiotics are an obvious place to start. The recently sequenced genomes of mammals that are divergent from human and mouse, including the tammar wallaby and the platypus, provide an opportunity to discover novel antimicrobials. Marsupials and monotremes are ideal potential sources of new antimicrobials because they give ...
|
| |
|
| |
Abstract
Recent mirror studies with two corvid species have reported contrasting findings. Jungle crows, Corvus macrorhynchos, showed no self-contingent behaviour when confronted with mirrors, whereas Eurasian magpies, Pica pica, reportedly passed the ‘mark’ test for self-recognition. We investigated mirror-induced behaviour in wild-caught New Caledonian crows, Corvus moneduloides. We first documented the response of 10 naïve crows to a 50 × 40 cm vertical mirror. The crows responded to their mirror image with social displays and engaged in search and mirror-directed exploratory behaviour. ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-24 00:27:33
Abstract
This chapter briefly reviews what is known—and what remains to be understood—about Grey parrot vocal learning. I review Greys’ physical capacities—issues of auditory perception and production—then discuss how these capacities are used in vocal learning and can be recruited for referential communication with humans. I discuss cross-species comparisons where applicable and conclude with a description of recent research that integrates issues of reference, production and perception. ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-23 23:39:01
Abstract
The ‘Support Problem’ is a benchmark test to investigate the understanding of spatial relationships between objects. We tested kea parrots' performance in a paradigm that has previously been studied in primates. Kea perform comparably well to tamarins when they are confronted with a choice between two support devices, one of which has a reward resting on it and the other slightly next to it, or when given a choice between a continuous and a disrupted support. Kea did better than chimpanzees ...
|
| |
Proceedings. Biological sciences / The Royal Society, Vol. 276, No. 1676. (7 December 2009), pp. 4155-4162, doi:10.1098/rspb.2009.1397
Abstract
Cerebral lateralization refers to the division of information processing in either hemisphere of the brain and is a ubiquitous trait among vertebrates and invertebrates. Given its widespread occurrence, it is likely that cerebral lateralization confers a fitness advantage. It has been hypothesized that this advantage takes the form of enhanced cognitive function, potentially via a dual processing mechanism whereby each hemisphere can be used to process specific types of information without contralateral interference. Here, we examined the influence of lateralization on ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-21 23:38:13
Abstract
Kleptoparasitism, the stealing of food items already procured by others, is a widespread foraging strategy in animals, yet the reasons why some taxa have evolved this strategy and others have not remain unresolved. It has been hypothesized that kleptoparasitism should be more profitable, and hence have more often evolved, in lineages featuring certain characteristics, such as a large body mass, an enlarged brain or a dependence on vertebrate prey. Alternatively, the evolution of kleptoparasitism could have been facilitated in certain ecological ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-21 23:37:01
|
| |
Abstract
Practically all animals are affected by humans, especially in urban areas. Although most species respond negatively to urbanization, some thrive in human-dominated settings. A central question in urban ecology is why some species adapt well to the presence of humans and others do not. We show that Northern Mockingbirds (Mimus polyglottos) nesting on the campus of a large university rapidly learn to assess the level of threat posed by different humans, and to respond accordingly. In a controlled experiment, we found ...
|
| |
Philosophical transactions of the Royal Society of London. Series B, Biological sciences, Vol. 361, No. 1465. (29 January 2006), pp. 23-43, doi:10.1098/rstb.2005.1736
Abstract
Comparative psychologists interested in the evolution of intelligence have focused their attention on social primates, whereas birds tend to be used as models of associative learning. However, corvids and parrots, which have forebrains relatively the same size as apes, live in complex social groups and have a long developmental period before becoming independent, have demonstrated ape-like intelligence. Although, ornithologists have documented thousands of hours observing ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-21 22:51:06
Abstract
To what extent do keas, Nestor notabilis, learn from each other? We tested eighteen captive keas, New Zealand parrots, in a tool use task involving visual feature discrimination and social learning. The keas were presented with two adjacent tubes, each containing a physically distinct baited platform. One platform could be collapsed by insertion of a block into the tube to release the bait; the other platform could not be collapsed. In contrast to birds that acted on their own (“individual learners“), ...
|
| |
Philosophical Transactions of the Royal Society B: Biological Sciences, Vol. 362, No. 1480. (29 April 2007), pp. 489-505, doi:10.1098/rstb.2006.1991
posted to no-tag
by InquilineKea
on 2011-09-21 22:33:54
Abstract
The ‘social intelligence hypothesis’ was originally conceived to explain how primates may have evolved their superior intellect and large brains when compared with other animals. Although some birds such as corvids may be intellectually comparable to apes, the same relationship between sociality and brain size seen in primates has not been found for birds, possibly suggesting a role for other non-social factors. But bird sociality is different from primate sociality. Most monkeys and apes form stable groups, whereas most birds are ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-21 22:28:44
|
| |
Abstract
Intelligence has evolved many times independently among vertebrates. Primates, elephants and cetaceans are assumed to be more intelligent than 'lower' mammals, the great apes and humans more than monkeys, and humans more than the great apes. Brain properties assumed to be relevant for intelligence are the (absolute or relative) size of the brain, cortex, prefrontal cortex and degree of encephalization. However, factors that correlate better with intelligence are the number of cortical neurons and conduction velocity, as the basis for information-processing ...
|
| |
Abstract
Vertebrate brains vary tremendously in size, but differences in form are more subtle. To bring out functional contrasts that are independent of absolute size, we have normalized brain component sizes to whole brain volume. The set of such volume fractions is the cerebrotype of a species. Using this approach in mammals we previously identified specific associations between cerebrotype and behavioral specializations. Among primates, cerebrotypes are ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-19 01:07:54
Abstract
The most studied comparison of aging and maximum lifespan potential (MLSP) among endotherms involves the 7-fold longevity difference between rats (MLSP 5y) and pigeons (MLSP 35y). A widely accepted theory explaining MLSP differences between species is the oxidative stress theory, which purports that reactive oxygen species (ROS) produced during mitochondrial respiration damage bio-molecules and eventually lead to the breakdown of regulatory systems and consequent death. Previous rat-pigeon studies compared only aspects of the oxidative stress theory and most concluded that the ...
|
| |
by Kevin M. Kocot, Johanna T. Cannon, Christiane Todt, et al.Mathew R. Citarella, Andrea B. Kohn, Achim Meyer, Scott R. Santos, Christoffer Schander, Leonid L. Moroz, Bernhard Lieb, Kenneth M. Halanych
Abstract
Evolutionary relationships among the eight major lineages of Mollusca have remained unresolved despite their diversity and importance. Previous investigations of molluscan phylogeny, based primarily on nuclear ribosomal gene sequences or morphological data, have been unsuccessful at elucidating these relationships. Recently, phylogenomic studies using dozens to hundreds of genes have greatly improved our understanding of deep animal relationships. However, limited genomic resources spanning molluscan diversity has prevented use of a phylogenomic approach. Here we use transcriptome and genome data from all major ...
|
| |
by Laurance R. Doyle, Joshua A. Carter, Daniel C. Fabrycky, et al.Robert W. Slawson, Steve B. Howell, Joshua N. Winn, Jerome A. Orosz, Andrej Prˇsa, William F. Welsh, Samuel N. Quinn, David Latham, Guillermo Torres, Lars A. Buchhave, Geoffrey W. Marcy, Jonathan J. Fortney, Avi Shporer, Eric B. Ford, Jack J. Lissauer, Darin Ragozzine, Michael Rucker, Natalie Batalha, Jon M. Jenkins, William J. Borucki, David Koch, Christopher K. Middour, Jennifer R. Hall, Sean McCauliff, Michael N. Fanelli, Elisa V. Quintana, Matthew J. Holman, Douglas A. Caldwell, Martin Still, Robert P. Stefanik, Warren R. Brown, Gilbert A. Esquerdo, Sumin Tang, Gabor Furesz, John C. Geary, Perry Berlind, Michael L. Calkins, Donald R. Short, Jason H. Steffen, Dimitar Sasselov, Edward W. Dunham, William D. Cochran, Alan Boss, Michael R. Haas, Derek Buzasi, Debra Fischer
posted to no-tag
by InquilineKea
on 2011-09-17 00:47:33
Abstract
We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20 and 69% as massive as ...
|
| |
Abstract
The 2011 March 11 Tohoku-Oki earthquake (Mw9.0) caused vast damages to the country. Large events beneath dense observation networks could bring breakthroughs to seismology and geodynamics, and here I report one such finding. The Japanese dense network of Global Positioning System (GPS) detected ...
|
| |
Abstract
Evidence for time-dependent calculations about future rewards is scarce in non-human animals. In non-human primates, only great apes are comparable with humans. Still, some species wait for several minutes to obtain a better reward in delayed exchange tasks. Corvids have been shown to match with non-human primates in some time-related tasks. Here, we investigate a delay of gratification in two corvid species, the carrion crow (Corvus corone) and the common raven (Corvus corax), in an exchange task. Results show that corvids ...
|
| |
by Jin-Ying Lu, Yu-Yi Lin, Jin-Chuan Sheu, et al.June-Tai Wu, Fang-Jen Lee, Yue Chen, Min-I Lin, Fu-Tien Chiang, Tong-Yuan Tai, Shelley L. Berger, Yingming Zhao, Keh-Sung Tsai, Heng Zhu, Lee-Ming Chuang, Jef D. Boeke
Abstract
Acetylation of histone and nonhistone proteins is an important posttranslational modification affecting many cellular processes. Here, we report that NuA4 acetylation of Sip2, a regulatory β subunit of the Snf1 complex (yeast AMP-activated protein kinase), decreases as cells age. Sip2 acetylation, controlled by antagonizing NuA4 acetyltransferase and Rpd3 deacetylase, enhances interaction with Snf1, the catalytic subunit of Snf1 complex. Sip2-Snf1 interaction inhibits Snf1 activity, thus decreasing phosphorylation of a downstream target, Sch9 (homolog of Akt/S6K), and ultimately leading to slower growth ...
|
| |
|
| |
posted to no-tag
by InquilineKea
on 2011-09-08 01:51:35
Abstract
The Community Atmosphere Model (CAM), a 3-dimensional Earth-based climate model, has been modified to simulate the dynamics of the Venus atmosphere. The most current finite volume version of CAM is used with Earth-related processes removed, parameters appropriate for Venus introduced, and some basic physics approximations adopted. A simplified Newtonian cooling approximation has been used for the radiation scheme. We use a high resolution (1° by 1° in latitude and longitude) to take account of small-scale dynamical processes that might be important ...
|
| |
(2 Mar 2009)
Abstract
The anomalous chemical abundances and the structure of the Edgewood-Kuiper belt observed in the solar system constrain the initial mass and radius of the star cluster in which the sun was born to $M∼eq500$ to 3000 \msun and $R∼eq 1$ to 3 pc. When the cluster dissolved the siblings of the sun dispersed through the galaxy, but they remained on a similar orbit around the Galactic center. Today these stars hide among the field stars, but 10 to 60 of them are still present within a distance ...
|
| |
posted to no-tag
by InquilineKea
on 2011-09-04 21:51:06
Abstract
Field and laboratory investigations of a 2690.83 Ma (207Pb/206Pb age of Saganaga Tonalite) unconformity exposed in outcrop in northeastern Minnesota, USA, reveal evidence for development of a deep paleoweathering profile with geochemical biosignatures consistent with the presence of microbial communities and weakly oxygenated conditions. Weathering profiles are characterized by a 5–50 m thick regolith that consists of saprolitized Saganaga Tonalite and Paulson Lake succession basaltic metavolcanic rocks retaining rock structure, which is cross-cut by a major unconformity surface marking development of a successor ...
|
| |
Medicine and science in sports and exercise, Vol. 36, No. 6. (June 2004), pp. 983-990
posted to no-tag
by InquilineKea
on 2011-09-04 18:08:16
Abstract
We conclude that enterically coated oral ATP supplementation may provide small ergogenic effects on muscular strength under some treatment conditions. ...
|
Search
