Mrs. V. Boudreau to Mr. Meredith (1 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1399/thumbnail.jp

“Challenge” and “Hindrance” Related Stress Among U.S. Managers

This study proposes that stress associated with two kinds of job demands or work circumstances, “challenges” and “hindrances,” are distinct phenomena that are differentially related to work outcomes. Specific hypotheses were derived from this general proposition and tested using a sample of 1,886 U.S. managers and longitudinal data. Regression results indicate that challenge related stress is positively related to job satisfaction and negatively related to job search. In contrast, hindrance related stress is negatively related to job satisfaction and positively related to job search and turnover

Solid-Liquid two-phase partitioning bioreactors for the treatment of gas.-phase VOCs

[Abstract] Two-Phase Partitioning Bioreactors (TPPBs) consist of a cell-containing aqueous phase and a separate, biocompatible and immiscible phase that partitions toxic substrates to the cells based on their metabolic demand and on maintaining the thermodynamic equilibrium of the system. TPPBs have traditionally used immiscible liquid organic solvents as the substrate delivery phase, however, one of the limitations of organic solvents is their potential bioavailability as substrates, and therefore these TPPB systems have generally been limited to the use of pure strains of organisms incapable of metabolizing the solvent. We have replaced the organic solvent phase in TPPBs with inert polymers (plastic beads). A TPPB employing styrene-butadiene beads as the sequestering phase was used to treat high step change loadings of BTEX in a contaminated air stream. The presence of the polymers allowed the system to effectively capture the incoming VOCs, buffer the cells from high VOC levels and release the VOCs to the cells for biodegradation. The polymer TPPB system demonstrated substantially higher performance than an aqueous phase bioscrubber and comparable performance to a solvent-aqueous TPPB. Also of great interest was the increase in oxygen transfer provided to the system by the addition of polymer beads, which have significant affinity for oxygen. The presence of polymer beads, which are biocompatible and non-bioavailable, provides a simple and effective means of enhancing the bioremediation of toxic organics present in gas streams, and potentially other phases

Carbon Distribution in the Stiliwater Complex and Evolution of Vapor During Crystallization of Stillwater and Bushveld Magmas

The occurrence and distribution of carbon in the Stillwater Complex have been investigated. In mineralized troctolite and associated rocks of olivine-bearing zone I (OB I), carbon is present as graphitic material and calcite. The assemblage forsterite-antigorite-calcite-graphite and the petro graphic relations indicate equilibration of the carbon-rich phases during serpentinization. Typical OB I troctolite contains 500-1100 ppm wt. carbon, 40-70% of which is in calcite, whereas troctolite from higher stratigraphic positions generally contains 2 log units below that of the Ni-NiO oxygen buffer. Upon the appearance of graphite, the fluid evolved to a more hydrogen-rich composition by graphite precipitation and loss of oxygen to the surrounding silicate-oxide assemblage. Cooling of fluid to 25°C below the first appearance of graphite resulted in reduction in the fluid mass by >70%, thus concentrating chlorine, sulfur and other residual species in the intercumulus fluid and melt. The model explains the presence of chlor-apatite and the enrichment of graphite in the Bushveld Critical Zone and predicts that chlor-apatite-bearing Stillwater rocks were similarly enriched in graphite during crystallizatio

Development of a real-time PCR assay for the specific detection and identification of Streptococcus pseudopneumoniae using the recA gene

AbstractWe sequenced the evolutionarily conserved genes 16S rRNA, atpD, tuf, and recA from Streptococcus pseudopneumoniae, Streptococcus pneumoniae, Streptococcus mitis, and Streptococcus oralis. Phylogenetic analysis revealed that recA provided good resolution between these species, including discrimination of the novel species S. pseudopneumoniae. By contrast, the more conserved 16S rRNA, tuf and atpD are not sufficiently discriminatory. Therefore, recA sequences were used to develop a real-time PCR assay with a locked nucleic acid-mediated TaqMan probe for the specific detection and identification of S. pseudopneumoniae. The PCR assay showed excellent specificity and a detection limit of <10 genome copies for the detection and identification of S. pseudopneumoniae strains, which makes it a promising tool for molecular identification and epidemiological studies. In conclusion, this article describes for the first time a PCR assay for the specific identification of S. pseudopneumoniae

Fast shower simulation in the ATLAS calorimeter

The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterisation is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to ~1 GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper

The ATLAS Simulation: an LHC Challenge

The simulation program for the ATLAS experiment at CERN is currently in a full operational mode and integrated into the ATLAS common analysis framework, Athena. The OO approach, based on GEANT4, and in use during the DC2 data challenge has been interfaced within Athena and to GEANT4 using the LCG dictionaries and Python scripting. The robustness of the application was proved during the DC2 data challenge. The Python interface has added the flexibility, modularity and interactivity that the simulation tool requires in order to be able to provide a common implementation of different full ATLAS simulation setups, test beams and cosmic ray applications. Generation, simulation and digitization steps were exercised for performance and robustness tests. The comparison with real data has been possible in the context of the ATLAS Combined Test Beam (2004) and ongoing cosmic ray studies

Bridged filaments of histone-like nucleoid structuring protein pause RNA polymerase and aid termination in bacteria.

Bacterial H-NS forms nucleoprotein filaments that spread on DNA and bridge distant DNA sites. H-NS filaments co-localize with sites of Rho-dependent termination in Escherichia coli, but their direct effects on transcriptional pausing and termination are untested. In this study, we report that bridged H-NS filaments strongly increase pausing by E. coli RNA polymerase at a subset of pause sites with high potential for backtracking. Bridged but not linear H-NS filaments promoted Rho-dependent termination by increasing pause dwell times and the kinetic window for Rho action. By observing single H-NS filaments and elongating RNA polymerase molecules using atomic force microscopy, we established that bridged filaments surround paused complexes. Our results favor a model in which H-NS-constrained changes in DNA supercoiling driven by transcription promote pausing at backtracking-susceptible sites. Our findings provide a mechanistic rationale for H-NS stimulation of Rho-dependent termination in horizontally transferred genes and during pervasive antisense and noncoding transcription in bacteria

Fools gold? Developer dilemmas in a closed mobile application market platform

In this paper, we outline some potential conflicts that platform owners and software developers face in mobile application markets. Our arguments are based on comments captured in specialized online discussion forums, in which developers gather to share knowledge and experiences. The key findings indicate conflicts of interests, including 1) intra-platform competition, 2) discriminative promotion, 3) entry prevention, 4) restricted monetization, 5) restricted knowledge sharing, 6) substitution, and 7) strategic technology selection. Opportunistic platform owners may use their power to discriminate between third-part software developers. However, there are also potential strategic solutions that developers can apply; for example diversification (multi-homing), syndication and brand building.Comment: Presented at the 15th International Conference on Electronic Commerce, ICEC 2013, Turku, Finland, August 13-15, 201

The Area of Pressure-Induced Referred Pain Is Dependent on the Intensity of the Suprathreshold Stimulus: An Explorative Study

Objective: To investigate the pain referral area (number of pixels) and extent (vector length) as elicited from increasing intensities of pressure-induced pain at the shoulder. Design: Cross-sectional design. Setting: Clinical laboratory setting. Participants: Twenty-two healthy men and women participated in two experimental sessions. Methods: Delayed onset of muscle soreness (DOMS) was induced in the dominant shoulder and assessed 24 hours later. Participants rated the level of DOMS on a 6-point Likert scale. Four different intensities (pressure pain threshold [PPT]+20%, PPT+30%, PPT+40%, and PPT+50%) were applied to the infraspinatus in a randomized, balanced fashion for 60 seconds from low to high intensity or vice versa. The resulting location, area, and extent of referred pain as drawn by the participants on a digital body chart were extracted and expressed in pixels. The extent of pain was defined as the vector length extending from the ipsilateral earlobe to the most distal location of the pain. Results: The referred pain area from PPT+20% was smaller than PPT+30%, PPT+40%, and PPT+50%. The extent of referred pain did not differ between the pressure pain intensities. Conclusions: Pressure intensity at PPT+30%, but no more, produces the greatest referred pain area as compared with the traditional pressure intensity of PPT+20%. Thus, the intensity of PPT+30% may be ideal for exploring the mechanisms of referred pain. The extent of the pain represents an independent expression of the intensity of the provoking stimulus and may be more closely related to the location of the stimulus