859 research outputs found

    A new purple sulfur bacterium from saline littoral sediments, Thiorhodotvibrio winogradskyi gen. nov. and sp. nov.

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    Two strains of a new purple sulfur bacterium were isolated in pure culture from the littoral sediment of a saline lake (Mahoney Lake, Canada) and a marine microbial mat from the North Sea island of Mellum, respectively. Single cells were vibrioid-to spirilloid-shaped and motile by means of single polar flagella. Intracellular photosynthetic membranes were of the vesicular type. As photosynthetic pigments, bacteriochlorophyll a and the carotenoids lycopene, rhodopin, anhydrorhodovibrin, rhodovibrin and spirilloxanthin were present. Hydrogen sulfide and elemental sulfur were used under anoxic conditions for phototrophic growth. In addition one strain (06511) used thiosulfate. Carbon dioxide, acetate and pyruvate were utilized by both strains as carbon sources. Depending on the strain propionate, succinate, fumarate, malate, tartrate, malonate, glycerol or peptone may additionally serve as carbon sources in the light. Optimum growth rates were obtained at pH 7.2, 33 °C, 50 mol m-2 s-1 intensity of daylight fluorescent tubes and a salinity of 2.2–3.2% NaCl. During growth on sulfide, up to ten small sulfur globules were formed inside the cells. The strains grew microaerophilic in the dark and exhibited high specific respiration rates. No vitamins were required for growth. The DNA base composition was 61.0–62.4 mol% G+C. The newly isolated bacterium belongs to the family chromatiaceae and is described as a member of a new genus and species, Thiorhodovibrio winogradskyi gen. nov. and sp. nov. with the type strain SSP1, DSM No. 6702

    Deletion of the GABAA α2-subunit does not alter self dministration of cocaine or reinstatement of cocaine seeking

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    Rationale GABAA receptors containing α2-subunits are highly represented in brain areas that are involved in motivation and reward, and have been associated with addiction to several drugs, including cocaine. We have shown previously that a deletion of the α2-subunit results in an absence of sensitisation to cocaine. Objective We investigated the reinforcing properties of cocaine in GABAA α2-subunit knockout (KO) mice using an intravenous self-administration procedure. Methods α2-subunit wildtype (WT), heterozygous (HT) and KO mice were trained to lever press for a 30 % condensed milk solution. After implantation with a jugular catheter, mice were trained to lever press for cocaine (0.5 mg/kg/infusion) during ten daily sessions. Responding was extinguished and the mice tested for cue- and cocaine-primed reinstatement. Separate groups of mice were trained to respond for decreasing doses of cocaine (0.25, 0.125, 0.06 and 0.03 mg/kg). Results No differences were found in acquisition of lever pressing for milk. All genotypes acquired self-administration of cocaine and did not differ in rates of self-administration, dose dependency or reinstatement. However, whilst WT and HT mice showed a dose-dependent increase in lever pressing during the cue presentation, KO mice did not. Conclusions Despite a reported absence of sensitisation, motivation to obtain cocaine remains unchanged in KO and HT mice. Reinstatement of cocaine seeking by cocaine and cocaine-paired cues is also unaffected. We postulate that whilst not directly involved in reward perception, the α2-subunit may be involved in modulating the “energising” aspect of cocaine’s effects on reward-seeking

    Envelope Determinants of Equine Lentiviral Vaccine Protection

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    Lentiviral envelope (Env) antigenic variation and associated immune evasion present major obstacles to vaccine development. The concept that Env is a critical determinant for vaccine efficacy is well accepted, however defined correlates of protection associated with Env variation have yet to be determined. We reported an attenuated equine infectious anemia virus (EIAV) vaccine study that directly examined the effect of lentiviral Env sequence variation on vaccine efficacy. The study identified a significant, inverse, linear correlation between vaccine efficacy and increasing divergence of the challenge virus Env gp90 protein compared to the vaccine virus gp90. The report demonstrated approximately 100% protection of immunized ponies from disease after challenge by virus with a homologous gp90 (EV0), and roughly 40% protection against challenge by virus (EV13) with a gp90 13% divergent from the vaccine strain. In the current study we examine whether the protection observed when challenging with the EV0 strain could be conferred to animals via chimeric challenge viruses between the EV0 and EV13 strains, allowing for mapping of protection to specific Env sequences. Viruses containing the EV13 proviral backbone and selected domains of the EV0 gp90 were constructed and in vitro and in vivo infectivity examined. Vaccine efficacy studies indicated that homology between the vaccine strain gp90 and the N-terminus of the challenge strain gp90 was capable of inducing immunity that resulted in significantly lower levels of post-challenge virus and significantly delayed the onset of disease. However, a homologous N-terminal region alone inserted in the EV13 backbone could not impart the 100% protection observed with the EV0 strain. Data presented here denote the complicated and potentially contradictory relationship between in vitro virulence and in vivo pathogenicity. The study highlights the importance of structural conformation for immunogens and emphasizes the need for antibody binding, not neutralizing, assays that correlate with vaccine protection. © 2013 Craigo et al

    Pleosporales

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    One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae

    High energy emission from microquasars

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    The microquasar phenomenon is associated with the production of jets by X-ray binaries and, as such, may be associated with the majority of such systems. In this chapter we briefly outline the associations, definite, probable, possible, and speculative, between such jets and X-ray, gamma-ray and particle emission.Comment: Contributing chapter to the book Cosmic Gamma-Ray Sources, K.S. Cheng and G.E. Romero (eds.), to be published by Kluwer Academic Publishers, Dordrecht, 2004. (19 pages

    Effect of the Heat Flux Density on the Evaporation Rate of a Distilled Water Drop

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    This paper presents the experimental dependence of the evaporation rate of a nondeaerated distilled water drop from the heat flux density on the surfaces of non-ferrous metals (copper and brass). A drop was placed on a heated substrate by electronic dosing device. To obtain drop profile we use a shadow optical system; drop symmetry was controlled by a high-speed video camera. It was found that the evaporation rate of a drop on a copper substrate is greater than on a brass. The evaporation rate increases intensively with raising volume of a drop. Calculated values of the heat flux density and the corresponding evaporation rates are presented in this work. The evaporation rate is found to increase intensively on the brass substrate with raising the heat flux density

    Synthesis and preliminary assessment of the anticancer and Wnt/β-catenin inhibitory activity of small amide libraries of fenamates and profens

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    As part of an ongoing program to study the anticancer activity of non-steroidal anti-inflammatory drugs (NSAIDs) through generating diversity libraries of multiple NSAID scaffolds, we synthesized a series of NSAID amide derivatives and screened these sets against three cancer cell lines (prostate, colon and breast) and Wnt/β-catenin signaling. The evaluated amide analog libraries show significant anticancer activity/cell proliferation inhibition, and specific members of the sets show inhibition of Wnt/β-catenin signaling.</p

    Hierarchical Bayesian estimation and hypothesis testing for delay discounting tasks

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    A state-of-the-art data analysis procedure is presented to conduct hierarchical Bayesian inference and hypothesis testing on delay discounting data. The delay discounting task is a key experimental paradigm used across a wide range of disciplines from economics, cognitive science, and neuroscience, all of which seek to understand how humans or animals trade off the immediacy verses the magnitude of a reward. Bayesian estimation allows rich inferences to be drawn, along with measures of confidence, based upon limited and noisy behavioural data. Hierarchical modelling allows more precise inferences to be made, thus using sometimes expensive or difficult to obtain data in the most efficient way. The proposed probabilistic generative model describes how participants compare the present subjective value of reward choices on a trial-to-trial basis, estimates participant- and group-level parameters. We infer discount rate as a function of reward size, allowing the magnitude effect to be measured. Demonstrations are provided to show how this analysis approach can aid hypothesis testing. The analysis is demonstrated on data from the popular 27-item monetary choice questionnaire (Kirby, Psychonomic Bulletin &amp; Review, 16(3), 457–462 2009), but will accept data from a range of protocols, including adaptive procedures. The software is made freely available to researchers

    Assertive community treatment for elderly people with severe mental illness

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    Background: Adults aged 65 and older with severe mental illnesses are a growing segment of the Dutch population. Some of them have a range of serious problems and are also difficult to engage. While assertive community treatment is a common model for treating difficult to engage severe mental illnesses patients, no special form of it is available for the elderly. A special assertive community treatment team for the elderly is developed in Rotterdam, the Netherlands and tested for its effectiveness.Methods: We will use a randomized controlled trial design to compare the effects of assertive community treatment for the elderly with those of care as usual. Primary outcome measures will be the number of dropouts, the number of patients engaged in care and patient's psychiatric symptoms, somatic symptoms, and social functioning. Secondary outcome measures are the number of unmet needs, the subjective quality of life and patients' satisfaction. Other secondary outcomes include the number of crisis contacts, rates of voluntary and involuntary admission, and length of stay. Inclusion criteria are aged 65 plus, the presence of a mental disorder, a lack of motivation for treatment and at least four suspected problems with functioning (addiction, somatic problems, daily living activities, housing etc.). If patients meet the inclusion criteria, they will be randomly allocated to either assertive community treatment for the elderly or care as usual. Trained assessors will use mainly observational instruments at the following time points: at baseline, after 9 and 18 months.Discussion: This study will help establish whether assertive community treatment for the elderly produces better results than care as usual in elderly people with severe mental illnesses who are difficult to engage. When assertive community treatment for the elderly proves valuable in these respects, it can be tested and implemented more widely, and mechanisms for its effects investigated

    Sex-specific disruption of murine midbrain astrocytic and dopaminergic developmental trajectories following antenatal GC treatment

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    The mammalian midbrain dopaminergic systems arising in the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) are critical for coping behaviours and are implicated in neuropsychiatric disorders where early life challenges comprise significant risk factors. Here, we aimed to advance our hypothesis that glucocorticoids (GCs), recognised key players in neurobiological programming, target development within these systems, with a novel focus on the astrocytic population. Mice received antenatal GC treatment (AGT) by including the synthetic GC, dexamethasone, in the mothers' drinking water on gestational days 16-19; controls received normal drinking water. Analyses of regional shapes and volumes of the adult SNc and VTA demonstrated that AGT induced long-term, dose-dependent, structural changes that were accompanied by profound effects on astrocytes (doubling/tripling of numbers and/or density). Additionally, AGT induced long-term changes in the population size and distribution of SNc/VTA dopaminergic neurons, confirming and extending our previous observations made in rats. Furthermore, glial/neuronal structural remodelling was sexually dimorphic and depended on the AGT dose and sub-region of the SNc/VTA. Investigations within the neonatal brain revealed that these long-term organisational effects of AGT depend, at least in part, on targeting perinatal processes that determine astrocyte density and programmed cell death in dopaminergic neurons. Collectively, our characterisation of enduring, AGT-induced, sex-specific cytoarchitectural disturbances suggests novel mechanistic links for the strong association between early environmental challenge (inappropriate exposure to excess GCs) and vulnerability to developing aberrant behaviours in later life, with translational implications for dopamine-associated disorders (such as schizophrenia, ADHD, autism, depression), which typically show a sex bia
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