Semileptonic transition of P wave bottomonium χb0(1P)\chi_{b0}(1P) to BcB_{c} meson

Taking into account the two-gluon condensate contributions, the transition form factors enrolled to the low energy effective Hamiltonian describing the semileptonic $\chi_{b0}\rightarrow B_{c}\ell\bar{\nu}, (\ell=(e,\mu,\tau))$ decay channel are calculated within three-point QCD sum rules. The fit function of the form factors then are used to estimate the decay width of the decay mode under consideration.Comment: 13 Pages, 3 Tables, 4 Figure

The role of the Rashba coupling in spin current of monolayer gapped graphene

In the current work we have investigated the influence of the Rashba spin-orbit coupling on spin-current of a single layer gapped graphene. It was shown that the Rashba coupling has a considerable role in generation of the spin-current of vertical spins in mono-layer graphene. The behavior of the spin-current is determined by density of impurities. It was also shown that the spin-current of the system could increase by increasing the Rashba coupling strength and band-gap of the graphene and the sign of the spin-current could be controlled by the direction of the current-driving electric field

Vasopressin attenuates ischemia-reperfusion injury via reduction of oxidative stress and inhibition of mitochondrial permeability transition pore opening in rat hearts

Aim of this study was to investigate the involvement of the mitochondrial permeability transition pore (MPTP) and oxidative stress in the cardioprotective effect of vasopressin (AVP) on ischemia/reperfusion (I/R) injury. Anesthetized male wistar rats were subjected to regional 30 min ischemia and 120 min reperfusion and randomly divided into nine groups: (1) Control; saline was administered intravenously before ischemia, (2) vasopressin was administrated 10 min prior to ischemia, (3, 4) Atractyloside as MPTP opener, was injected 5 min prior to reperfusion without and with vasopressin, (5, 6) Cyclosporine A as a MPTP closer, was injected 5 min prior to reperfusion without and with vasopressin, (7) mitochondria were isolated from control group and CaCl2 was added as MPTP opener and swelling inducer, (8) isolated mitochondria from Control hearts was incubated with Cyclosporine A before adding the CaCl2 (9) CaCl2 was added to isolated mitochondria from vasopressin group. Infusion of vasopressin decreased infarct size (18.6±1.7% vs. control group 37.6±2.4%), biochemical parameters [LDH (Lactate Dehydrogenase), CK-MB (Creatine Kinase-MB) and MDA (Malondialdehyde) plasma levels, PAB (Prooxidant-antioxidant balance)] compared to control group. Atactyloside suppressed the cardioprotective effect of vasopressin (32.5±1.9% vs. 18.6±1.7%) but administration of the Cyclosporine A without and with vasopressin significantly reduced infarct size to 17.7±4% (P<0.001) and 22.7±3% (P<0.01) respectively, vs. 37.6±2.4% in control group. Also, vasopressin, similar to Cyclosporine A, led to decrease in CaCl2-induced swelling. It seems that vasopressin through antioxidant effect and MPTP inhibition has created a cardioprotection against ischemia/reperfusion injuries. © 2015 Elsevier B.V. All rights reserved

Testing the accuracy of Foti's dental age estimation methods on a London UK sample

Background and aim: Tooth development and eruption are widely used in assessing dental age estimation, and one of the methods in using tooth development and eruption is Foti's method. However, the population used in the original study was French. Therefore, the aim of this study was to test the accuracy of Foti's four dental age estimation regression models against the East London population, mainly of the Bangladeshi and Caucasian ethnicity. These count the number of erupted teeth and tooth germs using a radiograph (Foti 1), absence of a radiograph (Foti 2), maxillary erupted teeth (Foti 3) and mandibular erupted teeth (Foti 4). Methods: The test sample was archived panoramic radiographs of 754 healthy patients aged 6–20 years (380 males and 374 females). The difference between dental and chronological ages was tested using a t-test. The mean absolute difference was also calculated for all models. The most accurate method was defined as the smallest mean difference, smallest standard deviation (SD) and mean absolute difference between dental and chronological ages. Results: Foti model 2 was most accurate with a mean difference of 0.11 years (SD 1.70 years) and a mean absolute difference of 1.33 years. Models 3 (maxillary erupted teeth) and 4 (mandibular erupted teeth) were marginally less accurate, whilst model 1 (radiograph) overestimated age on average by more than 5 years. Conclusion: Our findings show that estimating age using erupting teeth was most accurate using Foti model 2 (least bias)

Why do Large Animals Never Actuate Their Jumps with Latch-Mediated Springs? Because They can Jump Higher Without Them.

As animals get smaller, their ability to generate usable work from muscle contraction is decreased by the muscle's force-velocity properties, thereby reducing their effective jump height. Very small animals use a spring-actuated system, which prevents velocity effects from reducing available energy. Since force-velocity properties reduce the usable work in even larger animals, why don't larger animals use spring-actuated jumping systems as well? We will show that muscle length-tension properties limit spring-actuated systems to generating a maximum one-third of the possible work that a muscle could produce-greatly restricting the jumping height of spring-actuated jumpers. Thus a spring-actuated jumping animal has a jumping height that is one-third of the maximum possible jump height achievable were 100% of the possible muscle work available. Larger animals, which could theoretically use all of the available muscle energy, have a maximum jumping height that asymptotically approaches a value that is about three times higher than that of spring-actuated jumpers. Furthermore, a size related "crossover point" is evident for these two jumping mechanisms: animals smaller than this point can jump higher with a spring-actuated mechanism, while animals larger than this point can jump higher with a muscle-actuated mechanism. We demonstrate how this limit on energy storage is a consequence of the interaction between length-tension properties of muscles and spring stiffness. We indicate where this crossover point occurs based on modeling and then use jumping data from the literature to validate that larger jumping animals generate greater jump heights with muscle-actuated systems than spring-actuated systems