An implicit method for radiative transfer with the diffusion approximation in SPH

An implicit method for radiative transfer in SPH is described. The diffusion approximation is used, and the hydrodynamic calculations are performed by a fully three--dimensional SPH code. Instead of the energy equation of state for an ideal gas, various energy states and the dissociation of hydrogen molecules are considered in the energy calculation for a more realistic temperature and pressure determination. In order to test the implicit code, we have performed non--isothermal collapse simulations of a centrally condensed cloud, and have compared our results with those of finite difference calculations performed by MB93. The results produced by the two completely different numerical methods agree well with each other.Comment: 25 pages, 9 figure

Characterization of cadmium proteinuria in man and rat.

In workers chronically exposed to cadmium and without signs of renal insufficiency, plasma proteins with molecular weight ranging from 11,800 to 450,000 are excreted in greater amount in urine. Increased urinary excretion of low and high molecular weight proteins can occur independently. Because of its greater stability in urine and provided a sensitive immunological technique is used, the determination of retinol-binding protein is a more practical and reliable test of proximal tubular function than beta 2-microglobulin. The evaluation of renal function of workers removed from cadmium exposure indicates that cadmium-induced renal lesions, albeit of slow progression, are not reversible when exposures ceases. In workers chronically exposed to cadmium or removed from cadmium exposure, metallothionein in urine is directly correlated with cadmium in urine but not with cadmium in blood or years of cadmium exposure. The association between cadmium in urine and metallothionein in urine is independent of the status of renal function and the intensity of current exposure to cadmium. Whereas the repeated IP injection of high doses of cadmium to rat gives rise to a mixed or tubular type proteinuria, the prolonged oral administration of cadmium results mainly in the development of a glomerular type proteinuria. The former is usually reversible after cessation of treatment whereas the latter is not. Circulating antiglomerular basement membrane antibodies have been found in man and in rat chronically exposed to cadmium. The pathogenic significance of this finding deserves further investigation

Cross-flow filtration for the recovery of lipids from microalgae aqueous extracts: membrane selection and performances

International audienceThe biorefinery of microalgae necessitates innovative choices of soft and energy-efficient processes to guarantee the integrity of fragile molecules and develop eco-friendly production. A wet processing of biomass is proposed, which avoids expensive drying steps. It includes harvesting, cell disruption, and fractionation of the target compounds. Membrane filtration is a promising clean fractionation step. In this paper, the recovery of lipids from starving Parachlorella kessleri aqueous extracts by cross-flow filtration was studied. A model solution was formulated to test four membranes of different materials (PVDF, PES, PAN) and cut-offs (200 kDa - 1.5 µm). The hydrophilic PAN 500kDa membrane presented the best performance (flux stability, permeate flux, lipid retention, and cleanability) and was therfore selected for filtrating real aqueous extracts. Similar permeation fluxes were obtained with model and real products: 34 -41Lh-1m-2 respectively. The coalescence of lipid droplets was observed with model solutions but not with real products, less concentrated. The lipids from the real products were wholly retained by the PAN membrane, whereas some of the polysaccharides and proteins were able to permeate. An optimization of the coupling between culture, cell disruption, clarification, and filtration would allow a good concentration and purification of the lipids from microalgae

Role of personality in behavioral responses to new environments in captive panthera leo persica

Studying personality in captive animals may enable the development of more individual-based management decisions in terms of husbandry, enrichment, and breeding, which may help to improve overall animal welfare. The Asiatic lions (Panthera leo persica) at London Zoo represent an opportunity to research an understudied species\u2019 response to new environments. In the last few years, these lions have experienced several social and physical changes, such as new enclosures and increased social interaction with humans. This project aimed to investigate the role of personality in behavioral responses to these new environments. Lion personality questionnaires completed by keepers and direct focal animal observations were used to create personality profiles. Time budgets and enclosure use were determined and compared between control nights and human social event nights, and between the lions\u2019 previous enclosure and their new one. The results showed a lack of a difference in time budget and enclosure use between control nights and social event nights, and overall the Spread of Participation Index values revealed the lions use their enclosures unevenly. Personality profiles identified various traits (e.g., curious and eccentric) that could assist with individual-based management decisions, such as enrichment strategies. As the first study to assess Asiatic lions personality, this research contributes to the creation of consistent and valid methodology for evaluating captive animal personality. Personality assessment may help to improve husbandry and welfare protocols for individual lions, leading to the improved health and success of the species

Tuning complex shapes in Pt(0) nanoparticles : from cubic dendrites to five-fold stars

A platinum star performance: Quasi-single-crystalline Pt nanoparticles with peculiar morphologies—cubic dendrites, planar tripods, and fivefold stars—were synthesized in high yield. Shape selectivity was achieved by finely tuning the growth kinetics under a dihydrogen atmosphere

A faster algorithm for smoothed particle hydrodynamics with radiative transfer in the flux-limited diffusion approximation

We describe a new, faster implicit algorithm for solving the radiation hydrodynamics equations in the flux-limited diffusion approximation for smoothed particle hydrodynamics. This improves on the method elucidated in Whitehouse & Bate by using a Gauss-Seidel iterative method rather than iterating over the exchange of energy between pairs of particles. The new algorithm is typically many thousands of times faster than the old one, which will enable more complex problems to be solved. The new algorithm is tested using the same tests performed by Turner & Stone for ZEUS-2D, and repeated by Whitehouse & Bate.Comment: 12 pages, 7 figures. Accepted for publication in MNRA

Chemical Ordering in Bimetallic FeCo Nanoparticles: From a Direct Chemical Synthesis to Application As Efficient High-Frequency Magnetic Material

Single-crystalline FeCo nanoparticles with tunable size and shape were prepared by co-decomposing two metal-amide precursors under mild conditions. The nature of the ligands introduced in this organometallic synthesis drastically affects the reactivity of the precursors and, thus, the chemical distribution within the nanoparticles. The presence of the B2 short-range order was evidenced in FeCo nanoparticles prepared in the presence of HDAHCl ligands, combining 57 Fe Mössbauer, zero-field 59 Co ferromagnetic nuclear resonance (FNR), and X-ray diffraction studies. This is the first time that the B2 structure is directly formed during synthesis without the need of any annealing step. The as-prepared nanoparticles exhibit magnetic properties comparable with the ones for the bulk (M s = 226 Am 2 ·kg -1 ). Composite magnetic materials prepared from these FeCo nanoparticles led to a successful proof-of-concept of the integration on inductor-based filters (27% enhancement of the inductance value at 100 MHz)

Role of personality in behavioral responses to new environments in captive asiatic lions (Panthera leo persica)

Copyright © 2017 Giovanni Quintavalle Pastorino et al. Studying personality in captive animals may enable the development of individual-based management decisions, which may improve animal welfare. Asiatic lions at London Zoo represent an opportunity to research an understudied species' response to new environments since they have experienced social and physical changes, such as new enclosures and increased social interaction with humans. This project aimed to investigate the role of personality in behavioral responses to these changes. Lion personality questionnaires completed by keepers and direct focal animal observationswere used to create personality profiles. Time budgets and enclosure use were determined and compared between control nights and event nights and between the lions' previous enclosure and their new one.The results showed a lack of difference in time budget and enclosure use between control and so cial event nights, and the spread of participation index values revealed that the lions use their enclosures unevenly. Personality profiles identified various traits that could assist with individual-based management decisions. As the first study to assess Asiatic lions personality, this research contributes to the creation of consistent and valid methodology for evaluating captive animal personality that may improve husbandry and welfare protocols for individual lions, leading to the improved health and success of the species