Effects of stress on the immune system of fish

The effects of stress on the immune system of various fish species including dab Limanda limanda, flounder Platichthys flesus, sea bass Dicentrarchus labrax and gobies Zosterisessor ophiocephalus, were investigated from laboratory and field experiments, using various assays to measure immunocompetence, correlated with histological and ultrastructural observations. Modulation of the immune system was demonstrated at tissue, cellular and biochemical levels following exposure to various stressors. The spleen somatic index was depressed in dab stressed in the laboratory and gobies collected from polluted sites in the Venice Lagoon. Differential blood cell counts consistently showed an increase in phagocytes and decrease in thrombocytes in fish exposed to various stressors. Phagocytic activity from spleen and kidney adherent cells was stimulated in dab stressed by transportation but depressed in fish exposed to chemical pollutants. Respiratory burst activity in phagocytic cells was also stimulated in stressed dab but depressed in sea bass exposed to cadmium. The results are discussed in relation to current concepts on stress in fish and the regulation of the immune system

Electric potential distributions at the interface between plasmasheet clouds

At the interface between two plasma clouds with different densities, temperatures, and/or bulk velocities, there are large charge separation electric fields which can be modeled in the framework of a collisionless theory for tangential discontinuities. Two different classes of layers were identified: the first one corresponds to (stable) ion layers which are thicker than one ion Lamor radius; the second one corresponds to (unstable) electron layers which are only a few electron Larmor radii thick. It is suggested that these thin electron layers with large electric potential gradients (up to 400 mV/m) are the regions where large-amplitude electrostatic waves are spontaneously generated. These waves scatter the pitch angles of the ambient plasmasheet electron into the atmospheric loss cone. The unstable electron layers can therefore be considered as the seat of strong pitch angle scattering for the primary auroral electrons

ORIGAMIX, a CdTe-based spectro-imager development for nuclear applications

The Astrophysics Division of CEA Saclay has a long history in the development of CdTe based pixelated detection planes for X and gamma-ray astronomy, with time-resolved imaging and spectrometric capabilities. The last generation, named Caliste HD, is an all-in-one modular instrument that fulfills requirements for space applications. Its full-custom front-end electronics is designed to work over a large energy range from 2 keV to 1 MeV with excellent spectroscopic performances, in particular between 10 and 100 keV (0.56 keV FWHM and 0.67 keV FWHM at 13.9 and 59.5 keV). In the frame of the ORIGAMIX project, a consortium based on research laboratories and industrials has been settled in order to develop a new generation of gamma camera. The aim is to develop a system based on the Caliste architecture for post-accidental interventions or homeland security, but integrating new properties (advanced spectrometry, hybrid working mode) and suitable for industry. A first prototype was designed and tested to acquire feedback for further developments. In this study, we particularly focused on spectrometric performances with high energies and high fluxes. Therefore, our device was exposed to energies up to 700 keV (133Ba, 137Cs) and we measured the evolution of energy resolution (0.96 keV at 80 keV, 2.18 keV at 356 keV, 3.33 keV at 662 keV). Detection efficiency decreases after 150 keV, as Compton effect becomes dominant. However, CALISTE is also designed to handle multiple events, enabling Compton scattering reconstruction, which can drastically improve detection efficiencies and dynamic range for higher energies up to 1408 keV (22Na, 60Co, 152Eu) within a 1-mm thick detector. In particular, such spectrometric performances obtained with 152Eu and 60Co were never measured before with this kind of detector.Comment: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Available online 9 January 2015, ISSN 0168-9002 (http://www.sciencedirect.com/science/article/pii/S0168900215000133). Keywords: CdTe; X-ray; Gamma-ray; Spectrometry; Charge-sharing; Astrophysics Instrumentation; Nuclear Instrumentation; Gamma-ray camera

Room temperature soft ferromagnetism in the nanocrystalline form of YCo2 - a well-known bulk Pauli paramagnet

The Laves phase compound, YCo2, is a well-known exchange-enahnced Pauli paramagnet. We report here that, in the nanocrystalline form, this compound interestingly is an itinerant ferromagnet at room temperature with a low coercive-field. The magnitude of the saturation moment (about 1 Bohr-magneton per formula unit) is large enough to infer that the ferromagnetism is not a surface phenomenon in these nanocrystallites. Since these ferromagnetic nanocrystallines are easy to synthesize with a stable form in air, one can explore applications, particularly where hysteresis is a disadvantage

Years of Life Lost Because of Gunshot Injury to the Brain and Spinal Cord

Objective: A recent study (Lemaire) estimated the life expectancy loss attributable to gun deaths at 103.6 days for the overall U.S. population: 150.7 days for white males and 361.5 days for black males. This study estimates the life expectancy loss attributable to the premature death of individuals who initially survived gun-related traumatic brain injury (TBI) and spinal cord injury (SCI) in the United States. Design: Interpersonal TBI data were drawn from a surveillance system, and self-inflicted TBI data were obtained from the Web-based Injury Statistics and Reporting System. SCI data were obtained from a national database. Multiple decrement analysis was used to calculate the days of life lost to gunshot wounds to the brain and spinal cord, by race and gender, in the United States. Results: On average, across age, gender, and race, life expectancy in the United States is reduced by 3.1 days because of the shorter lifespan for individuals who survive an initial gunshot wound to the brain or spinal cord. Black males bear a disproportionate burden, losing 9.5 days, whereas white males lose 4.6 days. Black and white females lose 1.5 and 1.0 days, respectively. Conclusions: We add these findings to the Lemaire study, resulting in a total of 106.7 days of life expectancy loss from gunshot wounds for the U.S. population, with 371.0 days of life lost for black males

Bonus-malus Systems in a Deregulated Environment: Forecasting Market Shares Using Diffusion Models

In a deregulated insurance market, insurance carriers have an incentive to be innovative in their pricing decisions by segmenting their portfolios and designing new bonus-malus systems (BMS). This paper examines the evolution of market shares and claim frequencies in a two-company market, when one insurer breaks off the existing stability by introducing a super-discount class in its BMS. Several assumptions concerning policyholders and insurers behavior are tested. Diffusion theory is used to model the spread of the information concerning the new BMS among prospective customers. A wide variety of market outcomes results: one company may take over the market or the two may survive with equal or unequal market shares, each specializing in a specific niche of the market. Before engaging in an aggressive competitive behavior, insurers should consequently be reasonably confident in their assumptions concerning the reactions of their policyholders to the new BMS

Working memory, strategy execution, and strategy selection in mental arithmetic

A total of 72 participants estimated products of complex multiplications of two-digit operands (e.g., 63 x 78), using two strategies that differed in complexity. The simple strategy involved rounding both operands down to the closest decades (e.g., 60 _ 70), whereas the complex strategy required rounding both operands up to the closest decades (e.g., 70 _ 80). Participants accomplished this estimation task in two conditions: a no-load condition and a working-memory load condition in which executive components of working memory were taxed. The choice/no-choice method was used to obtain unbiased strategy execution and strategy selection data. Results showed that loading working memory resources led participants to poorer strategy execution. Additionally, participants selected the simple strategy more often under working-memory load. We discuss the implications of the results to further our understanding of variations in strategy selection and execution, as well as our understanding of the impact of working-memory load on arithmetic performance and other cognitive domains

Binding of Vac14 to neuronal nitric oxide synthase: Characterisation of a new internal PDZ-recognition motif

AbstractPDZ domains mediate protein interactions primarily through either classical recognition of carboxyl-terminal motifs or PDZ/PDZ domain associations. Several studies have also described internal modes of PDZ recognition, most of which depend on β-finger structures. Here, we describe a novel interaction between the PDZ domain of nNOS and Vac14, the activator of the PtdIns(3)P 5-kinase PIKfyve. Binding assays using various Vac14 deletion constructs revealed a β-finger independent interaction that is based on a novel internal motif. Mutational analyses reveal essential residues within the motif allowing us to define a new type of PDZ domain interaction