18,940 research outputs found

    Heterotic Action in SUGRA-SYM Background

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    We consider the generalization of the heterotic action considered by Cherkis and Schwarz where the chiral bosons are introduced in a manifestly covariant way using an auxiliary field. In particular, we construct the kappa-symmetric heterotic action in ten-dimensional supergravity background coupled to super Yang-Mills theory and prove its kappa-symmetry. The usual Bianchi identity of Type I supergravity with super Yang-Mills dH_3= -\tr F\wedge F is crucially used. For technical reason, the Yang-Mills field is restricted to be abelian.Comment: 12 pages, no figures, added comments in the acknowledgmen

    Cdk5 Phosphorylates Dopamine D2 Receptor and Attenuates Downstream Signaling

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    The dopamine D2 receptor (DRD2) is a key receptor that mediates dopamine-associated brain functions such as mood, reward, and emotion. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase whose function has been implicated in the brain reward circuit. In this study, we revealed that the serine 321 residue (S321) in the third intracellular loop of DRD2 (D2i3) is a novel regulatory site of Cdk5. Cdk5-dependent phosphorylation of S321 in the D2i3 was observed in in vitro and cell culture systems. We further observed that the phosphorylation of S321 impaired the agonist-stimulated surface expression of DRD2 and decreased G protein coupling to DRD2. Moreover, the downstream cAMP pathway was affected in the heterologous system and in primary neuronal cultures from p35 knockout embryos likely due to the reduced inhibitory activity of DRD2. These results indicate that Cdk5-mediated phosphorylation of S321 inhibits DRD2 function, providing a novel regulatory mechanism for dopamine signaling.X111111sciescopu

    Framing Future of Work Considerations through Climate and Built Environment Assessment of Volunteer Work Practices in the United States Equine Assisted Services

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    The foundation of healthy workplace design is an understanding of work practices. Volunteers comprise the majority of the workforce in care centers using horses to address human health issues. Documentation is lacking on protections for worker well-being in equestrian microenvironments which are known to have the potential for dust exposures. Climate acts as a master variable in equestrian facility design and ventilation usage to address dust and temperature concerns. Using climate as an independent variable, our objective was to characterize space usage, safety, environmental control, and organizational practices through a national survey of equine assisted programs. We found that more fully enclosed indoor arena spaces were in cold/very cold and mixed-humid climates (p = 0.0114). Annually more volunteers (p = 0.0073) work in these two climate groups averaging 100 volunteers per location. A total of 34% of all facilities, regardless of climate, do not use mechanical ventilation systems (e.g., fans). As volunteer worker time in the arena increased, time in the barn microenvironment tended to decrease (p = 0.0538). We identified facility designs, ventilation usage, and worker arrangements to refine the scalability of future air contaminant monitoring and to provide frameworks for education, workplace design, and prevention of exposure to dust

    Successive spin-flop transitions of a Neel-type antiferromagnet Li2MnO3 single crystal with a honeycomb lattice

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    We have carried out high magnetic field studies of single-crystalline Li2MnO3, a honeycomb lattice antiferromagnet. Its magnetic phase diagram was mapped out using magnetization measurements at applied fields up to 35 T. Our results show that it undergoes two successive meta-magnetic transitions around 9 T fields applied perpendicular to the ab plane (along the c* axis). These phase transitions are completely absent in the magnetization measured with the field applied along the ab plane. In order to understand this magnetic phase diagram, we developed a mean-field model starting from the correct Neel-type magnetic structure, consistent with our single crystal neutron diffraction data at zero field. Our model calculations succeeded in explaining the two meta-magnetic transitions that arise when Li2MnO3 enters two different spin-flop phases from the zero field Neel phase.open1187Nsciescopu

    Nucleotide sequence and expression of the ncr nickel and cobalt resistance in Hafnia alvei 5-5

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    The structural genes for the nickel and cobalt resistance of the conjugative plasmid pEJH 501 of Hafnia alvei 5-5, contained on a SalI-EcoRI fragment of 4.8 kb, were cloned and sequenced. The DNA sequence included five genes in the following order: ncrA, ncrB, ncrC, ncrY, and ncrX. The predicted amino acid sequences of ncrA were homologous to the amino acid sequences of nreB of Achromobacter xylosoxidans 31A. Expression of ncr with the T7 RNA polymerase-promoter system allowed Escherichia coli BL21 (DE3) to overexpress NcrA, NcrB, and NcrC but not NcrY, and NcrX. The apparent molecular masses of NcrA, NcrB, and NcrC were 30, 33, and 17 kDa, respectively. Primer-extension analysis showed that ncr mRNA started at nucleotide position 23 upstream from ncrA. The promoter region of the ncr operon possessed a strong, putative –35 element of σ32-type promoter sequence, and transcriptional 'lacZ fusion studies indicated that the –35 element influenced σ32-specific transcription. [Int Microbiol 2004; 7(1):27–34

    Disrupted-in-schizophrenia 1 (DISC1) and Syntaphilin collaborate to modulate axonal mitochondrial anchoring

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    In neuronal axons, the ratio of motile-to-stationary mitochondria is tightly regulated by neuronal activation, thereby meeting the need for local calcium buffering and maintaining the ATP supply. However, the molecular players and detailed regulatory mechanisms behind neuronal mitochondrial movement are not completely understood. Here, we found that neuronal activation-induced mitochondrial anchoring is regulated by Disrupted-in-schizophrenia 1 (DISC1), which is accomplished by functional association with Syntaphilin (SNPH). DISC1 deficiency resulted in reduced axonal mitochondrial movement, which was partially reversed by concomitant SNPH depletion. In addition, a SNPH deletion mutant lacking the sequence for interaction with DISC1 exhibited an enhanced mitochondrial anchoring effect than wild-type SNPH. Moreover, upon neuronal activation, mitochondrial movement was preserved by DISC1 overexpression, not showing immobilized response of mitochondria. Taken together, we propose that DISC1 in association with SNPH is a component of a modulatory complex that determines mitochondrial anchoring in response to neuronal activation.117Ysciescopu

    Automatic classification using concept knowledge of web documents

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    In order to classify web documents, we suggest a method using concept knowledge of category.In our study, the concept relations between keywords are extracted using hyperlink information and after the extracted keywords are classified into each category, these are used as an index.Then TFIDF for each category is extended to determine index weight value.The system is constructed for experimenting and estimating,which is consist of web robot, indexer, concept knowledge database for each category and the document classifier.Our system to be applied the extended TFIDF method shows an accuracy of 88% in automatic classifying of web documents

    Sorghum cobalt analysis on not determined wave length with atomic absorption spectrophotometer on background correction mode

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    This study was to know the better wave length on measuring cobalt content in forage sorghum hybrid (Sorghum bicolor) with an atomic absorption spectrophotometer. The analysis was on background correction mode with three wave lengths; 240.8, 240.7 (determined wave length or recommended wave length) and 240.6 nm, respectively. The larger absorbance value on the 240.7 nm, apparently, it might be considered as a good wave length but the smaller background value was a more important factor for the analysis as was shown on 240.6 nm. Correlation coefficients between the values on 240.7 nm: 240.6 nm and between them (240.8 nm: 240.6 nm) were higher and this common 240.6 nm was considered the better wave length.Key words: Atomic absorption spectrophotometer; background correction mode, cobalt analysis, forage sorghum, not determined wave lengths
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