Are there sex differences in the body size of the Eurasian red squirrel in Slovakia?

Sexual dimorphism of the Eurasian red squirrel on five somatic variables (head-and-body length, tail length, hind foot length, ear length and body weight) was evaluated on 55 squirrels. The overlap of values of the measured traits among sexes was high, but in all traits (with exception of the tail length) males seem to exhibit slightly higher mean values than females. However, these differences were non-significant, with the exception of a small significant difference in the tail length and tail-to-head-and-body ratio. Similarly, the results of discriminant function analysis show no differences between the sexes. Positive correlation analyses, together with PCA values, confirmed that tail length and hind foot length are traits that play a significant role in overall variability. We suggest that this relationship could explain their mutual importance in locomotion, where the feet are essential for movement in the trees. By contrast, the tail maintains balance on thin branches, or during jumps from one crown to another. Longer tails also demonstrate differential selection on males and females for a locomotor trait. Similarly, we discuss whether variations in tail length were connected to female reproductive success. Our results suggest that the non-significant results regarding SSD provide the benefit of the same size for both sexes in the protection of territory as well as inter- and intra-sexual interaction

Large momentum part of fermions with large scattering length

It is well known that the momentum distribution of the two-component Fermi gas with large scattering length has a tail proportional to $1/k^4$ at large $k$. We show that the magnitude of this tail is equal to the adiabatic derivative of the energy with respect to the reciprocal of the scattering length, multiplied by a simple constant. This result holds at any temperature (as long as the effective interaction radius is negligible) and any large scattering length; it also applies to few-body cases. We then show some more connections between the $1/k^4$ tail and various physical quantities, in particular the rate of change of energy in a DYNAMIC sweep of the inverse scattering length.Comment: 11 pages, 1 figure; a typo correcte

Dual Requirement for Yeast hnRNP Nab2p in mRNA poly(A) Tail Length Control and Nuclear Export

Recent studies of mRNA export factors have provided additional evidence for a mechanistic link between mRNA 3′‐end formation and nuclear export. Here, we identify Nab2p as a nuclear poly(A)‐binding protein required for both poly(A) tail length control and nuclear export of mRNA. Loss of NAB2 expression leads to hyperadenylation and nuclear accumulation of poly(A)+ RNA but, in contrast to mRNA export mutants, these defects can be uncoupled in a nab2 mutant strain. Previous studies have implicated the cytoplasmic poly(A) tail‐binding protein Pab1p in poly(A) tail length control during polyadenylation. Although cells are viable in the absence of NAB2 expression when PAB1 is overexpressed, Pab1p fails to resolve the nab2Δ hyperadenylation defect even when Pab1p is tagged with a nuclear localization sequence and targeted to the nucleus. These results indicate that Nab2p is essential for poly(A) tail length control in vivo, and we demonstrate that Nab2p activates polyadenylation, while inhibiting hyperadenylation, in the absence of Pab1p in vitro. We propose that Nab2p provides an important link between the termination of mRNA polyadenylation and nuclear export

Queue Length Asymptotics for Generalized Max-Weight Scheduling in the presence of Heavy-Tailed Traffic

We investigate the asymptotic behavior of the steady-state queue length distribution under generalized max-weight scheduling in the presence of heavy-tailed traffic. We consider a system consisting of two parallel queues, served by a single server. One of the queues receives heavy-tailed traffic, and the other receives light-tailed traffic. We study the class of throughput optimal max-weight-alpha scheduling policies, and derive an exact asymptotic characterization of the steady-state queue length distributions. In particular, we show that the tail of the light queue distribution is heavier than a power-law curve, whose tail coefficient we obtain explicitly. Our asymptotic characterization also contains an intuitively surprising result - the celebrated max-weight scheduling policy leads to the worst possible tail of the light queue distribution, among all non-idling policies. Motivated by the above negative result regarding the max-weight-alpha policy, we analyze a log-max-weight (LMW) scheduling policy. We show that the LMW policy guarantees an exponentially decaying light queue tail, while still being throughput optimal

On the characteristics of tidal structures of interacting galaxies

We present the results of our analysis of the geometrical tidal tail characteristics for nearby and distant interacting galaxies. The sample includes more than two hundred nearby galaxies and about seven hundred distant ones. The distant galaxies have been selected in several deep fields of the Hubble Space Telescope (HDF-N, HDF-S, HUDF, GOODS, GEMS) and they are at mean redshift z=0.65. We analyze the distributions of lengths and thicknesses for the tidal structures and show that the tails in distant galaxies are shorter than those in nearby ones. This effect can be partly attributed to observational selection effects, but, on the other hand, it may result from the general evolution of the sizes of spiral galaxies wih z. The location of interacting galaxies on the galaxy luminosity ($L$) -- tidal tail length ($l$) plane are shown to be explained by a simple geometrical model, with the upper envelope of the observed distribution being $l \propto \sqrt{L}$. We have solved the problem on the relationship between the observed distribution of tail flattening and the tail length in angular measure by assuming the tidal tails to be arcs of circumferences visible at arbitrary angles to the line of sight. We conclude that the angular length of the tidal tails visually distinguished in nearby and distant galaxies, on average, exceeds 180 degrees.Comment: 8 pages, 7 figures; Astron.Lett. vol.37, 201

Micellar Aggregates of Gemini Surfactants: Monte Carlo Simulation of a Microscopic Model

We propose a "microscopic" model of gemini surfactants in aqueous solution. Carrying out extensive Monte Carlo simulations, we study the variation of the critical micellar concentration (CMC) of these model gemini surfactants with the variation of the (a) length of the spacer connecting the two hydrophilic heads, (b) length of the hydrophobic tail and (c) the bending rigidity of the hydrocarbon chains forming the spacer and the tail; some of the trends of variation are counter-intuitive but are in excellent agreement with the available experimental results. Our simulations also elucidate the dependence of the shapes of the micellar aggregates and the magnitude of the CMC on the geometrical shape and size of the surfactant molecules and the electrical charge on the hydrophilic heads

Schottky barriers at metal-finite semiconducting carbon nanotube interfaces

Electronic properties of metal-finite semiconducting carbon nanotube interfaces are studied as a function of the nanotube length using a self-consistent tight-binding theory. We find that the shape of the potential barrier depends on the long-range tail of the charge transfer, leading to an injection barrier thickness comparable to half of the nanotube length until the nanotube reaches the bulk limit. The conductance of the nanotube junction shows a transition from tunneling to thermally-activated transport with increasing nanotube length

Optimal tail estimates for directed last passage site percolation with geometric random variables

In this paper, we obtain optimal uniform lower tail estimates for the probability distribution of the properly scaled length of the longest up/right path of the last passage site percolation model considered by Johansson in [12]. The estimates are used to prove a lower tail moderate deviation result for the model. The estimates also imply the convergence of moments, and also provide a verification of the universal scaling law relating the longitudinal and the transversal fluctuations of the model.Comment: AMS-LaTex, 41 pages, 17 figure