74 research outputs found
Specific Heat of a Three Dimensional Metal Near a T=0 Magnetic Transition with Dynamic Exponent z=2,3,4
We derive expressions for the universal contribution to the specific heat of
a three-dimensional metal near a zero-temperature phase transition with dynamic
exponent , or 4. The results allow a quantitative comparison of theory
to data. We illustrate the application of our results by analyzing data for
CeLuCuSi, which has been claimed to be near a quantum
critical point.Comment: 23 pages, revtex. For figures, send mail to [email protected]
Records and sequences of records from random variables with a linear trend
We consider records and sequences of records drawn from discrete time series
of the form , where the are independent and identically
distributed random variables and is a constant drift. For very small and
very large drift velocities, we investigate the asymptotic behavior of the
probability of a record occurring in the th step and the
probability that all entries are records, i.e. that . Our work is motivated by the analysis of temperature time series in
climatology, and by the study of mutational pathways in evolutionary biology.Comment: 21 pages, 7 figure
Retraction notice to "Differential impact of diabetes and hypertension in the brain: Adverse effects in grey matter" [Neurobiol. Dis., 44 (2011) 161–173, http://dx.doi.org/10.1016/j.nbd.2011.06.005]
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High "Normal" blood glucose is associated with decreased brain volume and cognitive performance in the 60s: the PATH through Life Study
Context:Type 2 diabetes is associated with cerebral atrophy, cognitive impairment and dementia. We recently showed higher glucose levels in the normal range not to be free of adverse effects and to be associated with greater hippocampal and amygdalar atrophy in older community-dwelling individuals free of diabetes.Objective:This study aimed to determine whether blood glucose levels in the normal range
Effects of different sources of carbohydrates on intake, digestibility, chewing, and performance of Holstein dairy cows
Dealing with Food and Eggs in Mouthbrooding Cichlids: Structural and Functional Trade-Offs in Fitness Related Traits
As in any vertebrate, heads of fishes are densely packed with functions. These functions often impose conflicting mechanical demands resulting in trade-offs in the species-specific phenotype. When phenotypical traits are linked to gender-specific parental behavior, we expect sexual differences in these trade-offs. This study aims to use mouthbrooding cichlids as an example to test hypotheses on evolutionary trade-offs between intricately linked traits that affect different aspects of fitness. We focused on the oral apparatus, which is not only equipped with features used to feed and breathe, but is also used for the incubation of eggs. We used this approach to study mouthbrooding as part of an integrated functional system with diverging performance requirements and to explore gender-specific selective environments within a species.Because cichlids are morphologically very diverse, we hypothesize that the implications of the added constraint of mouthbrooding will primarily depend on the dominant mode of feeding of the studied species. To test this, we compared the trade-off for two maternal mouthbrooding cichlid species: a "suction feeder" (Haplochromis piceatus) and a "biter" (H. fischeri). The comparison of morphology and performance of both species revealed clear interspecific and intersex differences. Our observation that females have larger heads was interpreted as a possible consequence of the fact that in both the studied species mouthbrooding is done by females only. As hypothesized, the observed sexual dimorphism in head shape is inferred as being suboptimal for some aspects of the feeding performance in each of the studied species. Our comparison also demonstrated that the suction feeding species had smaller egg clutches and more elongated eggs.Our findings support the hypothesis that there is a trade-off between mouthbrooding and feeding performance in the two studied haplochromine cichlids, stressing the importance of including species-specific information at the gender level when addressing interspecific functional/morphological differences
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