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We consider a compositionally and entropically stratified, compressible, rotating fluid earth and study gravitational-viscoelastic perturbations of its hydrostatic initial state. Using the Lagrangian representation and assuming infinitesimal perturbations, we deduce the incremental field equations and interface conditions of {\em gravitational viscoelastodynamics} (GVED) governing the perturbations. In particular, we distinguish the {\em material}, {\em material-local} and {\em local} forms of the incremental equations. We also demonstrate that their short-time asymptotes correspond to generalizations of the incremental field equations and interface conditions of {\em gravitational elastodynamics} (GED), whereas the long-time asymptotes agree with the incremental field equations and interface conditions of {\em gravitational viscodynamics} (GVD). The incremental thermodynamic pressure appearing in the long-time asymptote to the incremental constitutive equation is shown to satisfy the appropriate incremental state equation. Finally, we derive approximate field theories applying to gravitational-viscoelastic perturbations of isocompositional, isentropic and compressible or incompressible fluid domains.

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The objective of this study was to investigate the influence of water stress conditioning on the photosynthesis response of switchgrass (Panicum virgatum L.) and tall fescue (Festuca arundinacea Schreb.) to moisture deficiency. Tillers of the two species were grown in the same, controlled, environment and were subjected to three conditioning water stress cycles, or were kept well watered. After drought conditioning all plants were subjected to moisture deficiency while photosynthesis and leaf water potential were monitored. Measurements were taken between –0.8 and –4.0 MPa and the rate of water stress was 0.49 MPa/day. The conditioning of switchgrass produced a 26% reduction in the photosynthesis rate during drought, while that of tall fescue produced a 57% reduction in photosynthesis. Both species maintained elongation and photosynthesis down to lower leaf water potentials after drought conditioning than before conditioning. The conditioning water stress cycles decreased the leaf conductance, mesophyll resistance and transpiration of tall fescue plants after rewatering. The leaf water potential of conditioned switchgrass plants was lower upon rewatering after three conditioning water stress cycles than the leaf water potential of non-conditioned plants, while the leaf conductance, mesophyll resistance and transpiration of conditioned and non-conditioned tillers were equal. These data indicate an improvement in the drought tolerance of tall fescue and switchgrass plants, emphasize the importance of knowing the previous water stress history of the plants in moisture deficiency experiments, and help to choose proper irrigation management for switchgrass and tall fescue.

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Journal of Thermal Analysis and Calorimetry
Authors: K. Kafarska, D. Czakis-Sulikowska, and W. Wolf

Abstract  

New metal(II) complexes with empirical formulae Co(ibup)2·4H2O, Cd(ibup)2·3H2O, Co(nap)2·H2O, Cd(nap)2·3H2O (where ibup=(CH3)2CHCH2C6H4CH(CH3COO) and nap=CH3O(C10H6)CH(CH3COO)) were isolated and investigated. The complexes were characterized by elemental analysis, molar conductance, IR spectroscopy and thermal decomposition. The thermal behavior was studied by TG, DTG, DTA methods under non-isothermal conditions in air atmosphere. The hydrated complexes lose water molecules in first step. All complexes decompose via intermediate products to corresponding metal oxides CoO and CdO. A coupled TG-MS system was used to detect the principal volatile products of thermolysis and fragmentation processes of Co(nap)2·H2O. The IR spectra of studied complexes revealed also absorption of the carboxylate group. Principal concern with the position of asymmetric, symmetric frequencies. The value of their separation allow to deduce about type of coordination these groups.

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Switchgrass ( Panicum virgatum L.) biomass, which is of a good quality in the middle of summer, when cool-season grasses are unproductive, is a very important source of forage. This study measured the influence of the date of first harvest and cutting height on the first and regrowth yields of switchgrass cultivars Blackwell and Cave in Rock. The experiment was conducted in Blacksburg, VA, USA on a Groseclose-Poplimento soil to determine the influence of four dates of harvest and two cutting heights on the yield of switchgrass in 1990, and the influence of the treatments in previous years on the yields in 1991 and 1992. The first yield of both cultivars increased as the date of first harvest was delayed and the cutting height reduced. The regrowth yield of both cultivars declined as the date of first harvest was delayed. A shorter cutting height caused reductions in vigour and yield potential in the second year, whilst in the third year the harvested yield was only 40–50% of that obtained from previously unharvested stands.

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Abstract  

Differential scanning microcalorimetric measurements on phase transitions in water-oil-surfactant mixtures are presented, demonstrating that this method is highly sensitive towards small heat changes connected with structural transitions in the samples. The values for the latent heat of phase transitions are determined and the results are compared with predictions from mean field theory, emphasizing the role calorimetric experiments can play to identify the most important contributions to the free energy describing the mixtures. Doing this, the present status of the understanding of temperature dependent phase transitions in microemulsions is reviewed.

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Summary  

We have used inductively coupled plasma mass spectrometry (ICP-MS) as the primary tool for determining concentrations of a suite of nuclides in samples excised from high-burnup spent nuclear fuel rods taken from light water nuclear reactors. The complete analysis included the determination of 95Mo, 99Tc, 101Ru, 103Rh, 109Ag, 137Cs, 143Nd, 145Nd,148Nd,147Sm, 149Sm, 150Sm, 151Sm, 152Sm, 151Eu, 153Eu, 155Eu, 155Gd, 237Np, 234U, 235U, 236U, 238U, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 242mAm, and 243Am. The isotopic composition of fissiogenic lanthanide elements was determined using high-performance liquid chromatography (HPLC) with ICP-MS detection. These analytical results allow the determination of fuel burn-up based on 148Nd, Pu, and U content, as well as provide input for storage and disposal criticality calculations. Results show that ICP-MS along with HPLC-ICP-MS are suitable of performing routine determinations of most of these nuclides, with an uncertainty of ±10% at the 95% confidence level.

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Abstract

Rapid detection of antibiotic resistances of clinical bacterial strains would allow an early selective antibiotic therapy and a faster intervention and implementation of infection control measurements. In clinical practice, however, conventional antibiotic susceptibility tests of bacteria often need 24 h until the results are obtained. The metabolic heat production of bacteria is an excellent possibility to record their physiological activities and could therefore be used for a rapid discrimination of bacterial strains which are resistant or non-resistant to antibiotics and also to lytic bacteriophages, respectively. Unfortunately, conventional calorimeters suffer from need of comparably large volumes of bacterial suspensions are characterised by slow operation and high costs which restrict their application in clinical laboratories. The present paper demonstrates that a new type of calorimeters developed on silicon-chip technology enables the detection of antibiotic resistances on a minute-timescale. For this reasons, a prototype chip calorimeter was used which sensitivity is 20 nW related to the heat production of about 104 bacteria. For a clear discrimination of antibiotic resistance about 105 bacteria are required. The antibiotic resistances and susceptibilities of different strains of Staphylococcus aureus to cefoxitin and the sensitivities of S. aureus DSM 18421 and E. coli DSM 498 to a mixture of two bacteriophages were studied. Comparing the heat productions of cultures incubated with antibiotics or bacteriophages to those without these antibacterial preparations enabled a clear discrimination of resistant and non-resistant strains already after totally 2 h.

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The left part of the Epstein-Barr virus (EBV) genome exhibits a strong colinearity of structural and functional elements with the immunoglobulin (Ig) gene loci which is only partially reflected in nucleotide sequence homologies. We propose that this colinearity may be the result of an inter-dependent co-evolution of the immunoglobulin loci together with EBV. Our observation could help elucidating the mechanisms of somatic hypermutation, explaining the ability of EBV to accidentally cause tumors, and shedding more light on the general mechanisms of viral and organismal evolution. We suggest that persisting viruses served as a complement for the organismal germline like in a ping-pong game and outline The Ping-Pong Evolution Hypothesis.

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