Chromatin containing CENP-A and alpha-satellite DNA is a major component of the inner kinetochore plate

The pathway of molecular interactions leading to kinetochore assembly on mammalian chromosomes is unknown. Kinetochores could be specified by structural features of centromeric satellite DNA [1-3] or by specific DNA sequences, analogous to budding yeast centromeres, interspersed in centromeric satellite DNA arrays [4,5]. Alternatively, kinetochores could be epigenetic structures that replicate without strict dependence on DNA sequence [6-8]. We purified kinetochore-associated chromatin from human chromosomes by immunoprecipitation of CENP-A, a centromere-specific histone H3 homologue located in the inner plate of the kinetochore [6,9,10]. Hybridization and DNA sequence analyses of cloned kinetochore DNA fragments revealed alpha-satellite as the predominant sequence associated with CENP-A. A major site of micrococcal nuclease digestion was identified by mapping the termini of alpha-satellite clones, suggesting that the inner kinetochore plate contains phased arrays of CENP-A-alpha-satellite nucleosomes. These experiments demonstrate for the first time that complex satellite DNA is a structural component of the kinetochore. Further, because complex satellite DNA is evolutionarily unconserved, these results suggest that molecular recognition events necessary for kinetochore formation take place at the level of DNA conformation or epigenetic mechanisms rather than DNA sequence per se.     

Comparative Simulation of GIS-Based Rainwater Management Solutions

Rain Water Harvesting (RWH) as a solution for sustainable rainwater management is the focus of this research. To locate the potential sites for RWH, multi-criteria analysis following analytical hierarchy process using land-use/landcover, slope, drainage density, and runoff depth has been performed. By introducing continuous soil moisture accounting procedure in the globally used SCS-CN method, discrepancies in computed runoff values have been assessed. To appraise the usefulness of revised Soil Moisture Accounting (SMA) -enhanced SCS-CN models, a number of modifications have been compared. The models’ performance has been evaluated using R², Root Mean Square Error (RMSE), Nash Sutcliffe Efficiency (NSE), Percent BIAS (PBIAS) statistical indicators, and Rank Grading System (RGS) and the best has been selected to calculate the runoff depth for RWH potential zones. The resultant suitability map classifies Gurriala catchment into three suitability zones. 33.8% of the total area has been found as least suitable, comprised mainly of forest, residential land, and water bodies, while 46.8% and 19.4% of the area is recognized as moderately suitable and high suitable respectively. Selected suitable sites have been further classified into suitability zones for enhanced RWH structures and runoff volume contributed by each RWH structure has been computed. The total runoff potential of the area is 22.47 MCM that is enough to fulfill the water demands of suburban areas as a most inexpensive solution.

     

3D contact modelling of large plastic deformation in powder forming processes

In this paper, the three-dimensional large frictional contact deformation of powder forming process is modeled using a node-to-surface contact algorithm based on the penalty and augmented-Lagrange approaches. The technique is applied by imposing the normal and tangential contact constraints and modifying the contact properties of frictional slip. The Coulomb friction law is employed to simulate the friction between the rigid punch and the work piece. It is shown that the augmented-Lagrange technique significantly improves imposing of the constraints on contact surfaces. In order to predict the non-uniform relative density and stress distributions during the large deformation of powder die-pressing, the nonlinear contact friction algorithm is employed within the framework of large finite element deformation, in which a double-surface cap plasticity model is used for highly nonlinear behavior of powder. Finally, the numerical schemes are examined for accuracy and efficiency in modeling of a set of powder components.     

Combustion performance evaluation of air staging of palm oil blends

The problems of global warming and the unstable price of petroleum oils have led to a race to develop environmentally friendly biofuels, such as palm oil or ethanol derived from corn and sugar cane. Biofuels are a potential replacement for fossil fuel, since they are renewable and environmentally friendly. This paper evaluates the combustion performance and emission characteristics of Refined, Bleached, and Deodorized Palm Oil (RBDPO)/diesel blends B5, B10, B15, B20, and B25 by volume, using an industrial oil burner with and without secondary air. Wall temperature profiles along the combustion chamber axis were measured using a series of thermocouples fitted axially on the combustion chamber wall, and emissions released were measured using a gas analyzer. The results show that RBDPO blend B25 produced the maximum emission reduction of 56.9% of CO, 74.7% of NOx, 68.5% of SO(2), and 77.5% of UHC compared to petroleum diesel, while air staging (secondary air) in most cases reduces the emissions further. However, increasing concentrations of RBDPO in the blends also reduced the energy released from the combustion. The maximum wall temperature reduction was 62.7% for B25 at the exit of the combustion chamber.     

Reinforcement Learning for Multiple Access Control in Wireless Sensor Networks: Review, Model, and Open Issues

Wireless sensor networking is a viable communication technology among low-cost and energy-limited sensor nodes deployed in an environment. Due to high operational features, the application area of this technology is extended significantly but with some energy related challenges. One main cause of the nodes energy wasting in these networks is idle listening characterized with no communication activity. This drawback can be mitigated by the means of energy-efficient multiple access control schemes so as to minimize idle listening. In this paper, we discuss the applicability of distributed learning algorithms namely reinforcement learning towards multiple access control (MAC) in wireless sensor networks. We perform a comparative review of relevant work in the literature and then present a cooperative multi agent reinforcement learning framework for MAC design in wireless sensor networks. Accordingly, the paper concludes with some major challenges and open issues of distributed MAC design using reinforcement learning.     

Molten salt synthesis of in-situ TiC coating on graphite flakes

TiC coating was synthesized on graphite flakes (G_f) by molten salt synthesis (MSS) using metal Ti powder and alkali salts. Three different alkali chloride salts of KCl, NaCl, and NH₄Cl were selected as the molten salt media substrate. Two mass ratios of 1:3 and 1:5 were chosen for Ti: G_f ratio, and the mass ratio of the powder (Ti + G_f) to the salt was 1:1. The synthesis was carried out at a temperature of 1100°? for 4 h. XRD was used to study the effect of alkali chloride salts and the Ti: G_f mass ratio on the synthesized coating. FE-SEM and AFM were accomplished to investigate the carbide formation and microstructure of the samples. Results showed that TiC coating was formed at 1100 °C for 4 h with both mass ratios in all three alkali chloride salts, but KCl was found to be the optimum alkali chloride salt or reaction medium. FE-SEM results displayed the formation of uniform coatings, and results from AFM indicated that the surface roughness increased from 0.72 for G_f to 4.94 nm for TiC coated G_f.     

Theoretical and experimental investigations of the inverse emulsion polymerization of acrylamide

In this study, the inverse emulsion polymerization modeling of polyacrylamide with population balance equations (PBEs) was performed. The PBEs were derived on the basis of the zero–one kinetic model. The effects of the surfactant steric barrier and surfactant reaction with radicals, including monomeric radicals, on the radical entry rate into the particle were taken into account. In the modified model, the coagulation phenomenon was included through consideration of the effects of forces not included in the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory; these include hydration and steric forces in addition to DLVO forces. The effects of the surfactant and initiator concentrations on the conversion, particle size, and average molecular weight (MW) were investigated by simulation and experimental studies. Increasing the surfactant concentration initially increased the conversion and decreased MW. A further increase in the surfactant concentration resulted in a decrease in the conversion and an increase in MW. The average particle size decreased with an increase in the surfactant concentration. An increase in the initiator concentration led to an increase in the monomer conversion and a decrease in the average MW. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41916.     

Assessment of possible protective roles of selenium, zinc, and cis-stilbene oxide against acute T-2 toxin poisoning: a preliminary report

The efficacy of two free radical scavengers, selenium and zinc, and a microsomal epoxide hydrolase-inducing agent, cis-stilbene oxide on the acute toxicity of T-2 toxin, a potent cytotoxic trichothecene, was investigated. Mice were pretreated daily for 3 consecutive days with either zinc sulfate (4.4 mg/kg, intraperitoneally [i.p.]), sodium selenite (1, 2, and 3 mg/kg i.p.) or cis-stilbene oxide (50 mg/kg i.p.). A full 24-hr after the final dosing with these agents, mice were given T-2 toxin (2, 2.5, or 3 mg/kg i.p.). The acute lethal toxicity of T-2 toxin (2.5 mg/kg) was reduced by administration of only sodium selenite (3 mg/kg) and cis-stilbene oxide (50 mg/kg). No significant effect on weight gain was observed.