Colour Confinement and Deformed Baryons in Quantum Chromodynamics

The confinement of coloured entities in Quantum Chromodynamics (QCD) is traced to colour singletness of the observed entities. This is believed to arise from colour singlet state of quark-antiquark for mesons and a fully colour antisymmetric state for baryons. This demands a spherically symmetric baryon in the ground state. However it is pointed out that a deformed baryon in the ground state has been found to be extremely successful phenomenology. There are convincing experimental supports for a deformed nucleon as well. This means that something has been missed in the fundamental theory. In this paper this problem is traced to a new colour singlet state for baryons which has been missed hitherto and incorporation of which provides a consistent justification of a deformed baryon in the ground state. Interestingly this new colour singlet state is global in nature.Comment: 5 pages, 1 figur

A New Model of Quintessence Compact Stars in Rastall Theory of Gravity

In the present work, we study a new model of anisotropic compact stars in the regime of Rastall theory. To solve the Rastall field equations we have used the Karori and Barua (KB) ansatz along with the quintessence dark energy characterized by a parameter $\omega_{q}$ with $-1<\omega_{q}<-\frac{1}{3}$. We present a comparative study to demonstrate the physical acceptance of our proposed model. We compare the numerical values of physical parameters obtained from our model with those of general relativity ($GR$) model given by Bhar \cite{1} and observe that our model is more compatible (for some chosen values of Rastall dimensionless parameter $\gamma=\kappa\lambda$) with observational data than $GR$ model. For this analysis we have consider four different compact stars, $SAX J1808-3658 (SSI)$, $4U 1820-30$, $Vela X-12$ and $PSR J1416-2230$ with radii $7.07km$, $10km$, $9.99km$ and $10.3km$, respectively. In this investigation we also present some physical aspects of the proposed model necessary to check the validity of the model and inferred that our model is acceptable physically and geometrically.Comment: 20 pages, 16 figures, 8 tables, Accepted for Publication in Eur. Physical Journal

Ranking of Australian Economics Departments Based on Their Total and Per Academic Staff Research Output

This study uses cluster analysis to classify twenty-seven Australian economics teaching departments into groups that have similar quantities of research output, measured by two different publication counts, and similar quality of research output, measured by a citation count. Three distinct groups of departments are identified and factor analysis is used to rank the groups. Whether research output is measured in total or on a per staff basis, Melbourne is in the group that ranks first, the remaining members of the "group of eight" are in one or other of the top two groups, and at least fifteen other departments are always in the third-ranked group.Economics Departments, Australia, Ranking

Forager bees (Apis mellifera) highly express immune and detoxification genes in tissues associated with nectar processing.

Pollinators, including honey bees, routinely encounter potentially harmful microorganisms and phytochemicals during foraging. However, the mechanisms by which honey bees manage these potential threats are poorly understood. In this study, we examine the expression of antimicrobial, immune and detoxification genes in Apis mellifera and compare between forager and nurse bees using tissue-specific RNA-seq and qPCR. Our analysis revealed extensive tissue-specific expression of antimicrobial, immune signaling, and detoxification genes. Variation in gene expression between worker stages was pronounced in the mandibular and hypopharyngeal gland (HPG), where foragers were enriched in transcripts that encode antimicrobial peptides (AMPs) and immune response. Additionally, forager HPGs and mandibular glands were enriched in transcripts encoding detoxification enzymes, including some associated with xenobiotic metabolism. Using qPCR on an independent dataset, we verified differential expression of three AMP and three P450 genes between foragers and nurses. High expression of AMP genes in nectar-processing tissues suggests that these peptides may contribute to antimicrobial properties of honey or to honey bee defense against environmentally-acquired microorganisms. Together, these results suggest that worker role and tissue-specific expression of AMPs, and immune and detoxification enzymes may contribute to defense against microorganisms and xenobiotic compounds acquired while foraging

Dynamics of bidisperse suspensions under stokes flows: linear shear flow and eedimentation

Sedimenting and sheared bidisperse homogeneous suspensions of non-Brownian particles are investigated by numerical simulations in the limit of vanishing small Reynolds number and negligible inertia of the particles. The numerical approach is based on the solution of the three-dimensional Stokes equations forced by the presence of the dispersed phase. Multi-body hydrodynamic interactions are achieved by a low order multipole expansion of the velocity perturbation. The accuracy of the model is validated on analytic solutions of generic flow configurations involving a pair of particles. The first part of the paper aims at investigating the dynamics of monodisperse and bidisperse suspensions embedded in a linear shear flow. The macroscopic transport properties due to hydrodynamic and non hydrodynamic interactions (short range repulsion force) show good agreement with previous theoretical and experimental works on homogeneous monodisperse particles. Increasing the volumetric concentration of the suspension leads to an enhancement of particle fluctuations and self-diffusion. The velocity fluctuation tensor scales linearly up to 15% concentration. Multi-body interactions weaken the correlation of velocity fluctuations and lead to a diffusion like motion of the particles. Probability density functions show a clear transition from Gaussian to exponential tails while the concentration decreases. The behavior of bidisperse suspensions is more complicated, since the respective amount of small and large particles modifies the overall response of the flow. Our simulations show that, for a given concentration of both species, when the size ratio varies from 1 to 2.5, the fluctuation level of the small particles is strongly enhanced. A similar trend is observed on the evolution of the shear induced self-diffusion coefficient. Thus for a fixed and total concentration, increasing the respective volume fraction of large particles can double the velocity fluctuation of small particles. In the second part of the paper, the sedimentation of a single test particle embedded in a suspension of monodisperse particles allows the determination of basic hydrodynamic interactions involved in a bidisperse suspension. Good agreement is achieved when comparing the mean settling velocity and fluctuations levels of the test sphere with experiments. Two distinct behaviors are observed depending on the physical properties of the particle. The Lagrangian velocity autocorrelation function has a negative region when the test particle has a settling velocity twice as large as the reference velocity of the surrounding suspension. The test particle settles with a zig-zag vertical trajectory while a strong reduction of horizontal dispersion occurs. Then, several configurations of bidisperse settling suspensions are investigated. Mean velocity depends on concentration of both species, density ratio and size ratio. Results are compared with theoretical predictions at low concentration and empirical correlations when the assumption of a dilute regime is no longer valid. For particular configurations, a segregation instability sets in. Columnar patterns tend to collect particles of the same species and eventually a complete separation of the suspension is observed. The instability threshold is compared with experiments in the case of suspensions of buoyant and heavy spheres. The basic features are well reproduced by the simulation model

Quality of life after cesarean and vaginal delivery

Objective: Cesarean rates in recent decades have been increasing and a number of studies have shown that cesarean increases maternal morbidities. The aim of this study is to compare the quality of life after cesarean and vaginal delivery. Methods: This prospective study was carried out on 356 pregnant women visiting urban health centers in Shahroud City, Northeast Iran, in 2011. The subjects completed the quality of life questionnaire in the third trimester of pregnancy and at 8 weeks postpartum. Results: In primiparas, the mean global QOL scores for the cesarean and vaginal delivery groups were 67.65±12.7 and 72.12±11.8, respectively. Also, the scores for the physical, psychological and social domains of QOL as well as the global score of QOL were higher in the vaginal delivery group than the cesarean group (p<0.05). In the case of primiparas, multiple regression analysis revealed that after adjusting for education, desirability of pregnancy and the General Health Questionnaire score, the delivery type remained as a predictor of the scores for the physical (R2=1.7%; B=-3.826; p=0.031; CI [-7.301, -.350]) and social (R2=2.5%; B=-5.708; p=0.017; CI [-10.392, -1.023]) domains of QOL and the global QOL score (R2=2.6%; B=-4.065; p=0.006; CI [-6.964, -1.164]). While multiparas, there was no relationship between QOL and type of delivery. Conclusion: In this sample of low-risk women, cesarean negatively affected the QOL of primiparas. More studies with larger sample sizes should be conducted to examine the effects of cesarean on QOL in both primiparas and multiparas within a shorter period after delivery. © OMSB, 2013

Phantom Accretion by Five Dimensional Charged Black Hole

This paper deals with the dynamical behavior of phantom field near five dimensional charged black hole. We formulate equations of motion for steady-state spherically symmetric flow of phantom fluids. It is found that phantom energy accretes onto black holes for $u<0$. Further, the location of critical point of accretion are evaluated that leads to mass to charge ratio for 5D charged black hole. This ratio implies that accretion cannot transform a black hole into a naked singularity. We would like to mention here that this work is an irreducible extension of 4D charged black hole.Comment: 8 pages, accepted for publication in Mod. Phys. Lett.

Modelling of a compact anisotropic star as an anisotropic fluid sphere in f(T)f(T) gravity

In this paper, we have studied the new exact model of anisotropic star in $f(T)$ theory of gravity. The dynamical equations in $f(T)$ theory with the anisotropic fluid have been solved by using Krori-Barua solution. We have determined that all the obtained solutions are free from central singularity and potentially stable. The observed values of mass and radius of the different strange stars RX J 1856-37, Her X-1, and Vela X-12 have been used to calculate the values of unknown constants in Krori and Barua metric. The physical parameters like anisotropy, stability and redshift of the stars have been investigated in detail.Comment: Accepted in the Canadian Journal of Physic