Orientation order of dipole molecules in the surface of embryonic droplets

During the growth of embryonic droplets in an imperfect vapor the surface polar molecules pass from a disordered orientation state to an ordered orientation state, the transition size being on the order of 100 molecules. This transition poses an interesting model problem in the study of order-disorder transitions in the thermodynamics of small systems.     

A heparin-binding growth factor secreted by macrophage-like cells that is related to EGF.

Macrophage-like U-937 cells secrete a 22-kilodalton heparin-binding growth factor that is mitogenic for BALB-3T3 fibroblasts and smooth muscle cells, but not endothelial cells. The amino acid sequence predicted from complementary DNA clones indicates that the mitogen is a new member of the epidermal growth factor (EGF) family. This heparin-binding EGF-like growth factor (HB-EGF) binds to EGF receptors on A-431 epidermoid carcinoma cells and smooth muscle cells, but is a far more potent mitogen for smooth muscle cells than is EGF. HB-EGF is also expressed in cultured human macrophages and may be involved in macrophage-mediated cellular proliferation.     

Nuclear coupling and polarization in molecular transport junctions: beyond tunneling to function

Much current experimental research on transport in molecular junctions focuses on finite voltages, where substantial polarization-induced nonlinearities may result in technologically relevant device-type responses. Because molecules have strong polarization responses to changing charge state or external field, molecules isolated between electrodes can show strongly nonlinear current-voltage responses. For small applied voltages (up to approximately 0.3 volt), weak interaction between transporting electrons and molecular vibrations provides the basis for inelastic electron tunneling spectroscopy. At higher voltages and for certain time scale regimes, strong coupling effects occur, including Coulomb blockade, negative differential resistance, dynamical switching and switching noise, current hysteresis, heating, and chemical reactions. We discuss a general picture for such phenomena that arise from charging, strong correlation, and polarization (electronic and vibrational) effects in the molecule and at the interface.     

Electron transport in molecular wire junctions

Molecular conductance junctions are structures in which single molecules or small groups of molecules conduct electrical current between two electrodes. In such junctions, the connection between the molecule and the electrodes greatly affects the current-voltage characteristics. Despite several experimental and theoretical advances, including the understanding of simple systems, there is still limited correspondence between experimental and theoretical studies of these systems.     

Diffraction from polymerized membranes

Flexible polymerized membranes in a good solvent are expected to exhibit a remarkable low-temperature flat phase, characterized by a diverging bending rigidity, vanishing elastic constants, and large fluctuations both parallel and perpendicular to the surface. A theory of the equilibrium structure factor provides a good fit to extensive molecular dynamics simulations of simplified "tethered surface" models of these materials. These results show how information about the size, thickness, and internal structure of polymerized membranes can be extracted from diffraction experiments.     

Ringlike structure of the Deinococcus radiodurans genome: a key to radioresistance?

The bacterium Deinococcus radiodurans survives ionizing irradiation and other DNA-damaging assaults at doses that are lethal to all other organisms. How D. radiodurans accurately reconstructs its genome from hundreds of radiation-generated fragments in the absence of an intact template is unknown. Here we show that the D. radiodurans genome assumes an unusual toroidal morphology that may contribute to its radioresistance. We propose that, because of restricted diffusion within the tightly packed and laterally ordered DNA toroids, radiation-generated free DNA ends are held together, which may facilitate template-independent yet error-free joining of DNA breaks.     

The ecoresponsive genome of Daphnia pulex

We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.     

Ultralow calcium requirements of fungi facilitate use of calcium regulating agents to suppress host calcium-dependent defenses,synergizing infection by a mycoherbicide

Infection by many fungi activates a variety of calcium dependent defenses in the hosts, slowing or suppressing the attacker and limiting the efficacy of mycoherbicides. The calcium requirement for fungal growth is so low that it could only be implied based on fungi containing calcium-dependent signaling enzymes. Analytical grade media contain <2 microM calcium, and the addition of specific chelators does not affect fungal growth. Hydrophobic derivatives of the calcium-specific chelator BAPTA designed to traverse plant cuticles were synthesized in order to chelate calcium internally during fungal attack. Some chelators as well as calcium precipitating oxalate and channel blocker verapamil were applied with a weakly mycoherbicidal Colletotrichum coccodes to cotyledons of compatible Abutilon threophrasti. They suppressed calcium dependent callose biosynthesis in the weed and increased virulence but may have affected other calcium-dependent processes that facilitate virulence. The low calcium requirement of fungi, and their high affinity for calcium, allows the application of calcium-regulating agents as synergists for mycoherbicides where the weed uses calcium-dependent defenses.     

The influence of fasting on blood glucose,triglycerides, cholesterol,and alkaline phosphatase in rats

Serum concentrations of glucose, cholesterol, triglycerides, and serum alkaline phosphatase activity were measured over different periods of time of food deprivation in male rats. Thirty percent of non-fasted rat's sera was found to be lipemic. At 16 hours of fasting, glucose levels dropped by 30% compared to the level of the non-fasting control group, and remained at a relatively constant level for up to 48 hours of fasting. Triglyceride concentrations decreased at 16 hours after fasting. Serum cholesterol levels were not changed at any of the fasting periods compared to the non-fasted control group. Alkaline phosphatase activity was decreased at 8 hours of fasting, with further declines in activity of the serum enzyme seen at 16, 24, and 48 hours of fasting. It was concluded that at 16 to 18 hours fasting, a non-absorptive state had been reached in male rats.     

Peste des petits ruminants in Ethiopian goats

Summary An outbreak of disease characterised by fever, ocular and nasal discharge, coughing and sneezing, oral necrosis, diarrhoea, enteritis and pneumonia in goats was shown by the use of specific cDNA probes to have been peste des petits ruminants, confirmed for the first time in Ethiopia. Both morbidity and mortality rates were high in goats but sheep were not affected.

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Peste De Pequeños Rumiantes En Caprinos En Etiopia

Resumen Se presentó por vez primera en Etiopía, un brote de peste de pequeños rumiantes, la que fue detectada mediante el uso de de sondas cADN especificas. La enfermedad se caracterizó por fiebre, descargas ocular y nasal, tos, estornudos necrosis oral, diarrea, enteritis y neumonia. Tanto la morbilidad como la mortalidad fueron altas en caprinos pero no en ovinos.

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Peste Des Petits Ruminants Chez Des Chevres Ethiopiennes

Résumé Une maladie caractérisée par de la fièvre, des écoulements nasal et oculaire, de la toux et des éternuements, une nécrose orale, de la diarrhée, de l'entérite et une pneumonie est apparue chez des chèvres. L'utilisation de sondes à ADNc spécifiques a montré qu'il s'agissait de la peste des petits ruminants, confirmée pour la première fois en Ethiopie. Les taux de morbidité étaient élevés chez les chèvres mais les moutons n'étaient pas affectés.