Stress Management Factors In Education

The high percentage of faculty and staff absenteeism due to significant stressful situations was addressed by the implementation of Stress Management Workshops in the target school. This occurred at a secondary institution where there were five different approaches to the program: Guest speakers, movies, after school activities, environmental improvements and positive sharing. The workshop consisted of four guest speakers in the topics of: Stress Management Awareness, Time Management and Organizational Skills, Nutritional Needs During Stress, and Physical Fitness Related to Stress. All the speakers gave their presentations during morning school hours and nutritional morning munchies were served. Inservice points were awarded to all participants. Environmental improvements were made in the lounges. Participants were provided with fruit weekly as a nutritional boost. A movie was shown on the value system of the nation, comparing the different age groups and the relationship with peoples\u27 values. Positive informational notes were distributed weekly for a morale booster. Results showed a significant decrease in staff absenteeism due to stress

Weighing simulated galaxy clusters using lensing and X-ray

We aim at investigating potential biases in lensing and X-ray methods to measure the cluster mass profiles. We do so by performing realistic simulations of lensing and X-ray observations that are subsequently analyzed using observational techniques. The resulting mass estimates are compared among them and with the input models. Three clusters obtained from state-of-the-art hydrodynamical simulations, each of which has been projected along three independent lines-of-sight, are used for this analysis. We find that strong lensing models can be trusted over a limited region around the cluster core. Extrapolating the strong lensing mass models to outside the Einstein ring can lead to significant biases in the mass estimates, if the BCG is not modeled properly for example. Weak lensing mass measurements can be largely affected by substructures, depending on the method implemented to convert the shear into a mass estimate. Using non-parametric methods which combine weak and strong lensing data, the projected masses within R200 can be constrained with a precision of ~10%. De-projection of lensing masses increases the scatter around the true masses by more than a factor of two due to cluster triaxiality. X-ray mass measurements have much smaller scatter (about a factor of two smaller than the lensing masses) but they are generally biased low by 5-20%. This bias is ascribable to bulk motions in the gas of our simulated clusters. Using the lensing and the X-ray masses as proxies for the true and the hydrostatic equilibrium masses of the simulated clusters and averaging over the cluster sample we are able to measure the lack of hydrostatic equilibrium in the systems we have investigated.Comment: 27 pages, 21 figures, accepted for publication on A&A. Version with full resolution images can be found at http://pico.bo.astro.it/~massimo/Public/Papers/massComp.pd

The impact of mechanical shear on membrane flux and energy demand

The use of forced mechanical shear for both disc membranes (rotating and vibrating disc filtration, RDF and VDF respectively) and hollow fibres (vibrating HF membranes, VHFM) is reviewed. These systems have been extensively studied and, in the case of the disc membranes, have reached commercialisation and proven effective in achieving transmembrane pressure (TMP) control for various challenging feed waters. The effects of operating conditions, namely shear rate as enhanced by rotation and vibration speed and TMP, and feed water quality on the filtration flux and specific energy consumption are quantified as part of the review. A new relationship is revealed between the two empirical constants governing the classical relationship between membrane flux and shear rate, and a mathematical correlation proposed accordingly. A study of available information on energy reveals that operation at lower shear rates (i.e. rotation or vibration speeds) and more conservative fluxes leads to lower specific energy demands in kWh m−3 permeate, albeit with a larger required membrane area

Modelling discontinuities and Kelvin-Helmholtz instabilities in SPH

In this paper we discuss the treatment of discontinuities in Smoothed Particle Hydrodynamics (SPH) simulations. In particular we discuss the difference between integral and differential representations of the fluid equations in an SPH context and how this relates to the formulation of dissip ative terms for the capture of shocks and other discontinuities. This has important implications for many problems, in particular related to recently highlighted problems in treating Kelvin-Helmholtz instabilities across entropy gradients in SPH. The specific problems pointed out by Agertz et al. (2007) are shown to be related in particular to the (lack of) treatment of contact discontinuities in standard SPH formulations which can be cured by the simple application of an artificial thermal conductivity term. We propose a new formulation of artificial thermal conductivity in SPH which minimises dissipation away from discontinuities and can therefore be applied quite generally in SPH calculations.Comment: 31 pages, 10 figures, submitted to J. Comp. Phys. Movies + hires version available at http://www.astro.ex.ac.uk/people/dprice/pubs/kh/ . v3: modified as per referee's comments - comparison with Ritchie & Thomas formulation added, quite a few typos fixed. No major change in metho

Reaction kinetics of carbon dioxide with aqueous solutions of l-Arginine, Glycine & Sarcosine using the stopped flow technique

The use of amino acids as potential solvents for carbon dioxide (CO2) capture has been considered by a number of researchers. However, very little is known about the kinetics and mechanism of amino acids-CO2 reactions. In this work, we investigate the reactions of three amino acids (l-Arginine, Glycine and Sarcosine) with CO2 in aqueous media using stopped-flow conductivity technique. The experiments were performed at temperatures between 293 and 313K and amino acids concentrations were in the range of 0.05–0.2 molar. The overall rate constants (kov) was found to increase with increased amino acid concentration and solution temperature. Both zwitterion and termolecular mechanisms were used to model and interpret the data. However, the Zwitterion mechanism was found to be the preferred one. From the stopped-flow results at pH around 6, we found that neutral l-Arginine, Glycine and Sarcosine react with CO2(aq) with k(M−1s−1)=2.81×1010exp(−4482.9T(K)), k(M−1s−1)=3.29×1013exp(−8143.7T(K)) and k(M−1s−1)=3.90×1013exp(−7991.0T(K)) respectively. The corresponding activation energies are 37.28kJmol−1, 67.71kJmol−1 And 66.44kJmol−1 respectively. A comparison between the kinetics of the three amino acids showed that Arginine exhibits highest reaction rate with CO2 followed by Sarcosine and then Glycine. The technique and results obtained from this work can be used as strong tools in the development of efficient new solvents for the removal of CO2 from flue and industrial gases.This paper was made possible by an NPRP Grant # 7-1154-2-433 from the Qatar National Research Fund (a member of Qatar Foundation)

A connection between stress and development in the multicelular prokaryote Streptomyces coelicolor

Morphological changes leading to aerial mycelium formation and sporulation in the mycelial bacterium Streptomyces coelicolor rely on establishing distinct patterns of gene expression in separate regions of the colony. sH was identified previously as one of three paralogous sigma factors associated with stress responses in S. coelicolor. Here, we show that sigH and the upstream gene prsH (encoding a putative antisigma factor of sH) form an operon transcribed from two developmentally regulated promoters, sigHp1 and sigHp2. While sigHp1 activity is confined to the early phase of growth, transcription of sigHp2 is dramatically induced at the time of aerial hyphae formation. Localization of sigHp2 activity using a transcriptional fusion to the green fluorescent protein reporter gene (sigHp2–egfp) showed that sigHp2 transcription is spatially restricted to sporulating aerial hyphae in wild-type S. coelicolor. However, analysis of mutants unable to form aerial hyphae (bld mutants) showed that sigHp2 transcription and sH protein levels are dramatically upregulated in a bldD mutant, and that the sigHp2–egfp fusion was expressed ectopically in the substrate mycelium in the bldD background. Finally, a protein possessing sigHp2 promoter-binding activity was purified to homogeneity from crude mycelial extracts of S. coelicolor and shown to be BldD. The BldD binding site in the sigHp2 promoter was defined by DNase I footprinting. These data show that expression of sH is subject to temporal and spatial regulation during colony development, that this tissue-specific regulation is mediated directly by the developmental transcription factor BldD and suggest that stress and developmental programmes may be intimately connected in Streptomyces morphogenesis

Measuring the three-dimensional shear from simulation data, with applications to weak gravitational lensing

We have developed a new three-dimensional algorithm, based on the standard P$^3$M method, for computing deflections due to weak gravitational lensing. We compare the results of this method with those of the two-dimensional planar approach, and rigorously outline the conditions under which the two approaches are equivalent. Our new algorithm uses a Fast Fourier Transform convolution method for speed, and has a variable softening feature to provide a realistic interpretation of the large-scale structure in a simulation. The output values of the code are compared with those from the Ewald summation method, which we describe and develop in detail. With an optimal choice of the high frequency filtering in the Fourier convolution, the maximum errors, when using only a single particle, are about 7 per cent, with an rms error less than 2 per cent. For ensembles of particles, used in typical $N$-body simulations, the rms errors are typically 0.3 per cent. We describe how the output from the algorithm can be used to generate distributions of magnification, source ellipticity, shear and convergence for large-scale structure.Comment: 22 pages, latex, 11 figure

Discovering study-specific gene regulatory networks

This article has been made available through the Brunel Open Access Publishing Fund.Microarrays are commonly used in biology because of their ability to simultaneously measure thousands of genes under different conditions. Due to their structure, typically containing a high amount of variables but far fewer samples, scalable network analysis techniques are often employed. In particular, consensus approaches have been recently used that combine multiple microarray studies in order to find networks that are more robust. The purpose of this paper, however, is to combine multiple microarray studies to automatically identify subnetworks that are distinctive to specific experimental conditions rather than common to them all. To better understand key regulatory mechanisms and how they change under different conditions, we derive unique networks from multiple independent networks built using glasso which goes beyond standard correlations. This involves calculating cluster prediction accuracies to detect the most predictive genes for a specific set of conditions. We differentiate between accuracies calculated using cross-validation within a selected cluster of studies (the intra prediction accuracy) and those calculated on a set of independent studies belonging to different study clusters (inter prediction accuracy). Finally, we compare our method's results to related state-of-the art techniques. We explore how the proposed pipeline performs on both synthetic data and real data (wheat and Fusarium). Our results show that subnetworks can be identified reliably that are specific to subsets of studies and that these networks reflect key mechanisms that are fundamental to the experimental conditions in each of those subsets