Slow dynamics in cylindrically confined colloidal suspensions

We study bidisperse colloidal suspensions confined within glass microcapillary tubes to model the glass transition in confined cylindrical geometries. We use high speed three-dimensional confocal microscopy to observe particle motions for a wide range of volume fractions and tube radii. Holding volume fraction constant, we find that particles move slower in thinner tubes. The tube walls induce a gradient in particle mobility: particles move substantially slower near the walls. This suggests that the confinement-induced glassiness may be due to an interfacial effect.Comment: Submitted to AIP conference proceedings for "Slow Dynamics in Complex Systems" (Sendai, Japan, Dec. 2012

Electrochemical treatment of Poultry Slaughterhouse Wastewater using Iron and Aluminium Electrodes

Electrochemical process for the treatment of poultry slaughterhouse wastewater (PSWW) was studied. The effects of some key factors such as initial pH, current density, operating time and the kind of electrodes on the removal of chemical oxygen demand (COD), oil and grease, total suspended solids (TSS), total kjeldahl nitrogen (TKN) and total phosphors (TP) were investigated. It is clear that the process has a good efficiency. The highest removal amount of COD (95.6) was achieved with aluminium electrode (pH value between 2 and 3 and charge passed 20.34x10(3) colons (current density 0.014 A cm(-2)). 95.3 of oil and grease was removed in the same conditions, of course, in the case of iron electrode. The maximum removal efficiency for TKN and TP were 77.8 and 89.6 respectively (pH 3, charge passed 30.51x10(3) colons and with aluminium). Consequently electrocoagulation is comparatively suitable process for PSWW treatment

A prospective study of the effect of delivery type on neonatal weight gain pattern in exclusively breastfed neonates born in Shiraz, Iran

<p>Abstract</p> <p>Background</p> <p>In this exploratory study, the contribution of delivery type to the weight gain pattern for full-term infants with exclusive breastfeeding in the first month of infancy was determined. In addition, breastfeeding success among cesarean section (C-section) delivery mothers based on their neonate's weight gain at the end of the first month of infancy was evaluated.</p> <p>Methods</p> <p>A cohort of 92 neonates born in Shiraz, from July 10 to August 10, 2007 was followed longitudinally. The data were collected during the first month postpartum at three occasions: 3 to 7 days postpartum, 10-21 days postpartum and 24-31 days postpartum.</p> <p>Results</p> <p>Among 92 mothers in this study, 35 (38%) were delivered by C-section. Generalized estimating equation (GEE) showed that delivery type (p < 0.01), receipt of advice about breastfeeding (p = 0.03) and neonate's age (p < 0.01) significantly affected weight gain. GEE estimated the values of the parameters under study and the testing contribution of each factor to weight gain, leading to the conclusion that gender, parities and maternal education did not contribute to weight gain. The neonate's weight gain pattern for C-section deliveries lies below that of normal vaginal deliveries until 25 days postpartum, when weight gain for C-section deliveries became higher than that for normal vaginal deliveries.</p> <p>Conclusions</p> <p>Type of delivery contributes strongly to the weight gain pattern in the first month of infancy. In spite of greater weight loss among C-section birth neonates in the first days of life, at the end of the first month neonates showed a similar weight gain. Consequently, mothers with C-section delivery can successfully exclusively breastfeed.</p

Effect of repetitive feedbackon residents' communication skills improvement

Peer reviewedPublisher PD

Integrating latent classes in the Bayesian shared parameter joint model of longitudinal and survival outcomes

Cystic fibrosis is a chronic lung disease requiring frequent lung-function monitoring to track acute respiratory events (pulmonary exacerbations). The association between lung-function trajectory and time-to-first exacerbation can be characterized using joint longitudinal-survival modeling. Joint models specified through the shared parameter framework quantify the strength of association between such outcomes but do not incorporate latent sub-populations reflective of heterogeneous disease progression. Conversely, latent class joint models explicitly postulate the existence of sub-populations but do not directly quantify the strength of association. Furthermore, choosing the optimal number of classes using established metrics like deviance information criterion is computationally intensive in complex models. To overcome these limitations, we integrate latent classes in the shared parameter joint model through a fully Bayesian approach. To choose the optimal number of classes, we construct a mixture model assuming more latent classes than present in the data, thereby asymptotically “emptying” superfluous latent classes, provided the Dirichlet prior on class proportions is sufficiently uninformative. Model properties are evaluated in simulation studies. Application to data from the US Cystic Fibrosis Registry supports the existence of three sub-populations corresponding to lung-function trajectories with high initial forced expiratory volume in 1 s (FEV1), rapid FEV1 decline, and low but steady FEV1 progression. The association between FEV1 and hazard of exacerbation was negative in each class, but magnitude varied

Tachyon Tunnelling in D-brane-anti-D-brane

Using the tachyon DBI action proposal for the effective theory of non-coincident D$_p$-brane-anti-D$_p$-brane system, we study the decay of this system in the tachyon channel. We assume that the branes separation is held fixed, i.e. no throat formation, and then find the bounce solution which describe the decay of the system from false to the true vacuum of the tachyon potential. We shall show that due to the non-standard form of the kinetic term in the effective action, the thin wall approximation for calculating the bubble nucleation rate gives a result which is independent of the branes separation. This unusual result might indicate that the true decay of this metastable system should be via a solution that represents a throat formation as well as the tachyon tunneling.Comment: 15 pages, 4 figures, Latex file, minor changes, reference adde

New model for the interaction of IQGAP1 with CDC42 and RAC1

The specific and rapid formation of protein complexes, involving IQGAP family proteins,is essential for diverse cellular processes, such as adhesion, polarization, and directional migration. Although CDC42 and RAC1, prominent members of the RHO GTPase family, have been implicated in binding to and activating IQGAP1, the exact nature of this protein-protein recognition process has remained obscure. Here, we propose a mechanistic framework model that is based on a multiple-step binding process, which is a prerequisite for the dynamic functions of IQGAP1 as a scaffolding protein and a critical mechanism in temporal regulation andintegration of cellular pathways