Baculovirus Per Os Infectivity Factors Form a Complex on the Surface of Occlusion-Derived Virus

Five highly conserved per os infectivity factors, PIF1, PIF2, PIF3, PIF4, and P74, have been reported to be essential for oral infectivity of baculovirus occlusion-derived virus (ODV) in insect larvae. Three of these proteins, P74, PIF1, and PIF2, were thought to function in virus binding to insect midgut cells. In this paper evidence is provided that PIF1, PIF2, and PIF3 form a stable complex on the surface of ODV particles of the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV). The complex could withstand 2% SDS-5% ß-mercaptoethanol with heating at 50°C for 5 min. The complex was not formed when any of the genes for PIF1, PIF2, or PIF3 was deleted, while reinsertion of these genes into AcMNPV restored the complex. Coimmunoprecipitation analysis independently confirmed the interactions of the three PIF proteins and revealed in addition that P74 is also associated with this complex. However, deletion of the p74 gene did not affect formation of the PIF1-PIF2-PIF3 complex. Electron microscopy analysis showed that PIF1 and PIF2 are localized on the surface of the ODV with a scattered distribution. This distribution did not change for PIF1 or PIF2 when the gene for PIF2 or PIF1 protein was deleted. We propose that PIF1, PIF2, PIF3, and P74 form an evolutionarily conserved complex on the ODV surface, which has an essential function in the initial stages of baculovirus oral infectio

Generalized uncertainty principle and correction value to the black hole entropy

Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-Hawking entropy of the black hole. In particular, many researchers have expressed a vested interest in the coefficient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty principle and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is negative. This result is different from the known result at present. Our method is valid not only for single horizon spacetime but also for double horizons spacetime. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the condition that Bekenstein-Hawking area theorem is valid

Existence and Stability of Symmetric Periodic Simultaneous Binary Collision Orbits in the Planar Pairwise Symmetric Four-Body Problem

We extend our previous analytic existence of a symmetric periodic simultaneous binary collision orbit in a regularized fully symmetric equal mass four-body problem to the analytic existence of a symmetric periodic simultaneous binary collision orbit in a regularized planar pairwise symmetric equal mass four-body problem. We then use a continuation method to numerically find symmetric periodic simultaneous binary collision orbits in a regularized planar pairwise symmetric 1, m, 1, m four-body problem for $m$ between 0 and 1. Numerical estimates of the the characteristic multipliers show that these periodic orbits are linearly stability when $0.54\leq m\leq 1$, and are linearly unstable when $0<m\leq0.53$.Comment: 6 figure

Repulsion and attraction in high Tc superconductors

The influence of repulsion and attraction in high-Tc superconductors to the gap functions is studied. A systematic method is proposed to compute the gap functions using the irreducible representations of the point group. It is found that a pure s-wave superconductivity exists only at very low temperatures, and attractive potentials on the near shells significantly expand the gap functions and increase significantly the critical temperature of superconductivity. A strong on-site repulsion drives the $A_{1g}$ gap into a $B_{1g}$ gap. It is expected that superconductivity with the $A_{1g}$ symmetry reaches a high critical temperature due to the cooperation of the on-site and the next-nearest neighbor attractions.Comment: 4 pages, 5figure

Disentangling the effects of early caregiving experience and heritable factors on brain white matter development in rhesus monkeys

Early social experiences, particularly maternal care, shape behavioral and physiological development in primates. Thus, it is not surprising that adverse caregiving, such as child maltreatment leads to a vast array of poor developmental outcomes, including increased risk for psychopathology across the lifespan. Studies of the underlying neurobiology of this risk have identified structural and functional alterations in cortico-limbic brain circuits that seem particularly sensitive to these early adverse experiences and are associated with anxiety and affective disorders. However, it is not understood how these neurobiological alterations unfold during development as it is very difficult to study these early phases in humans, where the effects of maltreatment experience cannot be disentangled from heritable traits. The current study examined the specific effects of experience (“nurture”)versus heritable factors (“nature”)on the development of brain white matter (WM)tracts with putative roles in socioemotional behavior in primates from birth through the juvenile period. For this we used a randomized crossfostering experimental design in a naturalistic rhesus monkey model of infant maltreatment, where infant monkeys were randomly assigned at birth to either a mother with a history of maltreating her infants, or a competent mother. Using a longitudinal diffusion tensor imaging (DTI)atlas-based tract-profile approach we identified widespread, but also specific, maturational changes on major brain tracts, as well as alterations in a measure of WM integrity (fractional anisotropy, FA)in the middle longitudinal fasciculus (MdLF)and the inferior longitudinal fasciculus (ILF), of maltreated animals, suggesting decreased structural integrity in these tracts due to early adverse experience. Exploratory voxelwise analyses confirmed the tract-based approach, finding additional effects of early adversity, biological mother, social dominance rank, and sex in other WM tracts. These results suggest tract-specific effects of postnatal maternal care experience versus heritable or biological factors on primate WM microstructural development. Further studies are needed to determine the specific behavioral outcomes and biological mechanisms associated with these alterations in WM integrity

Rheological Chaos in a Scalar Shear-Thickening Model

We study a simple scalar constitutive equation for a shear-thickening material at zero Reynolds number, in which the shear stress \sigma is driven at a constant shear rate \dot\gamma and relaxes by two parallel decay processes: a nonlinear decay at a nonmonotonic rate R(\sigma_1) and a linear decay at rate \lambda\sigma_2. Here \sigma_{1,2}(t) = \tau_{1,2}^{-1}\int_0^t\sigma(t')\exp[-(t-t')/\tau_{1,2}] {\rm d}t' are two retarded stresses. For suitable parameters, the steady state flow curve is monotonic but unstable; this arises when \tau_2>\tau_1 and 0>R'(\sigma)>-\lambda so that monotonicity is restored only through the strongly retarded term (which might model a slow evolution of material structure under stress). Within the unstable region we find a period-doubling sequence leading to chaos. Instability, but not chaos, persists even for the case \tau_1\to 0. A similar generic mechanism might also arise in shear thinning systems and in some banded flows.Comment: Reference added; typos corrected. To appear in PRE Rap. Com

Shear-banding in a lyotropic lamellar phase, Part 2: Temporal fluctuations

We analyze the temporal fluctuations of the flow field associated to a shear-induced transition in a lyotropic lamellar phase: the layering transition of the onion texture. In the first part of this work [Salmon et al., submitted to Phys. Rev. E], we have evidenced banded flows at the onset of this shear-induced transition which are well accounted for by the classical picture of shear-banding. In the present paper, we focus on the temporal fluctuations of the flow field recorded in the coexistence domain. These striking dynamics are very slow (100--1000s) and cannot be due to external mechanical noise. Using velocimetry coupled to structural measurements, we show that these fluctuations are due to a motion of the interface separating the two differently sheared bands. Such a motion seems to be governed by the fluctuations of $\sigma^\star$, the local stress at the interface between the two bands. Our results thus provide more evidence for the relevance of the classical mechanical approach of shear-banding even if the mechanism leading to the fluctuations of $\sigma^\star$ remains unclear

Central obesity as a precursor to the metabolic syndrome in the AusDiab study and Mauritius

Evidence from epidemiologic studies that central obesity precedes future metabolic change and does not occur concurrently with the appearance of the blood pressure, glucose, and lipid abnormalities that characterize the metabolic syndrome (MetS) has been lacking. Longitudinal surveys were conducted in Mauritius in 1987, 1992, and 1998, and in Australia in 2000 and 2005 (AusDiab). This analysis included men and women (aged 25 years) in three cohorts: AusDiab 2000&ndash;2005 (n = 5,039), Mauritius 1987&ndash;1992 (n = 2,849), and Mauritius 1987&ndash;1998 (n = 1,999). MetS components included waist circumference, systolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, and homeostasis model assessment of insulin sensitivity (HOMA-S) (representing insulin sensitivity). Linear regression was used to determine which baseline components predicted deterioration in other MetS components over 5 years in AusDiab and 5 and 11 years in Mauritius, adjusted for age, sex, and ethnic group. Baseline waist circumference predicted deterioration (P &lt; 0.01) in four of the other six MetS variables tested in AusDiab, five of six in Mauritius 1987&ndash;1992, and four of six in Mauritius 1987&ndash;1998. In contrast, an increase in waist circumference between baseline and follow-up was only predicted by insulin sensitivity (HOMA-S) at baseline, and only in one of the three cohorts. These results suggest that central obesity plays a central role in the development of the MetS and appears to precede the appearance of the other MetS components.<br /

Quantum optics in the phase space - A tutorial on Gaussian states

In this tutorial, we introduce the basic concepts and mathematical tools needed for phase-space description of a very common class of states, whose phase properties are described by Gaussian Wigner functions: the Gaussian states. In particular, we address their manipulation, evolution and characterization in view of their application to quantum information.Comment: Tutorial. 23 pages, 1 figure. Updated version accepted for publication in EPJ - ST devoted to the memory of Federico Casagrand

Genetic Algorithm in the Optimization of the Acoustic Attenuation System

[EN] It is well known that Genetic Algorithms (GA) is an optimization method which can be used in problems where the traditional optimization techniques are difficult to be applied. Sonic Crystals (SC) are periodic structures that present ranges of sound frequencies related with the periodicity of the structure, where the sound propagation is forbidden. This means that in the acoustic spectrum there are ranges of frequencies with high acoustic attenuation. This attenuation can be improved producing vacancies in the structure. In this paper we use a parallel implementation of a GA to optimize those structures, by means of the creation of vacancies in a starting SC, in order to obtain the best acoustic attenuation in a predetermined range of frequencies. The cost function used in GA is based on the Multiple Scattering Theory (MST), which is a self consistent method for calculating acoustic pressure in SCs. As a final result we achieve a quasi ordered structures that presents a high acoustic attenuation in a predetermined range of frequencies, independent of the periodicity of the SC.The authors acknowledge financial support provided by the Spanish MEC (Project No. MAT2006-03097) and by the Generalitat Valenciana (Spain) under Grant No. GV/2007/191. This work also has been partially supported by MEC (Spanish government) and FEDER funds: projects DPI2005-07835, DPI2004- 8383-C03-02 and GVA-026.Romero García, V.; Fuster García, E.; Sánchez Pérez, JV.; García Raffi, LM.; Blasco, X.; Herrero Durá, JM.; Sanchís Saez, J. (2007). Genetic Algorithm in the Optimization of the Acoustic Attenuation System. Lecture Notes in Computer Science. 4507:614-621. https://doi.org/10.1007/978-3-540-73007-1_74S6146214507Martínez-Sala, R., Sancho, J., Sánchez Pérez, J.V., Llinares, J., Meseguer, F.: Sound attenuation by sculpture. Nature (London) 387, 241 (1995)Hushwaha, M.S., Halevi, P., Martínez, G., Dobrynski, L., Djafari-Rouhani, B.: Theory of acoustic band structure of periodic elastic composites. Phys. Rev. B 49(4), 2313–2322 (1994)Liu, Z., Zhang, X., Mao, Y., Zhu, Y.Y., Yang, Z., Xhan, C.T., Sheng, P.: Locally resonatn sonic materials. Science 289, 1734 (2000)Hu, X., Chan, C.T., Zi, J.: Two dimensional sonic crystals with Helmholtz resonators. Phys. Rev. E 71, 055601 (2005)Umnova, O., Attenborough, K., Linton, C.M.: Effects of porous covering on sound attenuation by poriodi arrays of cylinders. J. Acoust. Soc. Am. 119, 278 (2006)Caballero, D., Sánchez-Dehesa, J., Martínez-Sala, R., Rubio, C., Sánchez Pérez, J.V.S., Sanchis, L., Meseguer, F.: Suzuki phase in two-dimensional sonic crystals. Phys. Rev. B 64, 064303 (2001)Hakansson, A., Sánchez-Dehesa, J., Sanchis, L.: Acoustic lens design by genetic algorithms. Phys. Rev. B 70, 214302 (2004)Romero-García, V., Fuster, E., García-Raffi, L.M., Sánchez-Pérez, E.A., Sopena, M., Llinares, J., Sánchez-Pérez, J.V.: Band gap creation using quasiordered strutures based on sonic crystals. Appl. Phys. Lett. 88, 174104-1 174104-3 (2006)Chen, Y.Y., Ye, Z.: Theoretical analysis of acoustic stop bands in two-dimensional periodic scattering arrays. Phys. Rev. E 64, 036616 (2001)Economou, E.N., Sigalas, M.M.: Classical wave propagation in periodic structures: Cermet versus network topology. Phys. Rev. B 48(18), 13434 (1993)Sigalas, M.M., Economou, E.N., Kafesaki, M.: Spectral gaps for electromagnietic and scalar waves: Possible explanation for certain differences. Phys. Rev. B 50(5), 3393 (1994)Goldberg, D.E.: Genetic Algorithms in search, optimization and machine learning. Addison-Wesley, London (1989)Bäck, T.: Evolutionaty Algorithms in theory and practice. Oxford University Press, New York (1996)Baker, J.E.: Reducing bias and inefficiency in the selection algorithm. In: Proc. Second International Conference on Genetic Algorithms (1987)Mühlenbein, H., Schlierkamp-Voosen, D.: Predictive Models for the Breeder Genetic Algorithm I. Continuous Parameter Optimization. Evolutionary Computation 1(1) (1993)Cantú-Paz, E.: A summary of resaearch on parallel genetic algorithms. Technical Report 95007, Illinois Genetic Algorithms Laboratory. IlliGAL (1995