1,250 research outputs found
Reactivity of Sodium Pentaphospholide Na[cyclo-P5] towards CâĄE (E=C, N, P) Triple Bonds
A diglyme solution of Na[cyclo-P5] (1) reacts with alkynes and isolobal nitriles and phosphaalkynes to afford the otherwise elusive (aza)phospholide anions 2âaâc, 4âa,b, and 6. The reaction of Na[cyclo-P5] with alkynes and nitriles was studied by means of DFT methods, which suggested a concerted mechanism for the formation of 2âa and 4âb. The anions 2âaâc, 4âa,b, and 6 coordinate in an η5-fashion towards FeII to give the sandwich (aza)phosphametallocenes 3âaâc, 5âa,b and 7 in moderate to good yields. The new compounds were characterized by means of multinuclear NMR spectroscopy, single-crystal X-ray diffraction and cyclic voltammetry
Informal ActionâAdjudicationâRule Making: Some Recent Developments in Federal Administrative Law
Direct energy consumption of ICT hardware is only âhalf the story.â In order to get the âwhole story,â energy consumption during the entire life cycle has to be taken into account. This chapter is a first step toward a more comprehensive picture, showing the âgrey energyâ (i.e., the overall energy requirements) as well as the releases (into air, water, and soil) during the entire life cycle of exemplary ICT hardware devices by applying the life cycle assessment method. The examples calculated show that a focus on direct energy consumption alone fails to take account of relevant parts of the total energy consumption of ICT hardware as well as the relevance of the production phase. As a general tendency, the production phase is more and more important the smaller (and the more energy-efficient) the devices are. When in use, a tablet computer is much more energy-efficient than a desktop computer system with its various components, so its production phase has a much greater relative importance. Accordingly, the impacts due to data transfer when using Internet services are also increasingly relevant the smaller the end-user device is, reaching up to more than 90Â % of the overall impact when using a tablet computer.QC 20140825</p
Medicinal plant preparations administered by botswana traditional health practitioners for treatment of worm infections show anthelmintic activities
Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 mug/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 mug/mL
Correlated ab-initio calculations for ground-state properties of II-VI semiconductors
Correlated ab-initio ground-state calculations, using relativistic
energy-consistent pseudopotentials, are performed for six II-VI semiconductors.
Valence () correlations are evaluated using the coupled cluster approach
with single and double excitations. An incremental scheme is applied based on
correlation contributions of localized bond orbitals and of pairs and triples
of such bonds. In view of the high polarity of the bonds in II-VI compounds, we
examine both, ionic and covalent embedding schemes for the calculation of
individual bond increments. Also, a partitioning of the correlation energy
according to local ionic increments is tested. Core-valence ()
correlation effects are taken into account via a core-polarization potential.
Combining the results at the correlated level with corresponding Hartree-Fock
data we recover about 94% of the experimental cohesive energies; lattice
constants are accurate to \sim 1%; bulk moduli are on average 10% too large
compared with experiment.Comment: 10 pages, twocolumn, RevTex, 3 figures, accepted Phys. Rev.
4MOST Consortium Survey 3: Milky Way Disc and Bulge Low-Resolution Survey (4MIDABLE-LR)
The mechanisms of the formation and evolution of the Milky Way are encoded in
the orbits, chemistry and ages of its stars. With the 4MOST MIlky way Disk And
BuLgE Low-Resolution Survey (4MIDABLE-LR) we aim to study kinematic and
chemical substructures in the Milky Way disc and bulge region with samples of
unprecedented size out to larger distances and greater precision than
conceivable with Gaia alone or any other ongoing or planned survey. Gaia gives
us the unique opportunity for target selection based almost entirely on
parallax and magnitude range, hence increasing the efficiency in sampling
larger Milky Way volumes with well-defined and effective selection functions.
Our main goal is to provide a detailed chrono-chemo-kinematical extended map of
our Galaxy and the largest Gaia follow-up down to magnitudes (Vega).
The complex nature of the disc components (for example, large target densities
and highly structured extinction distribution in the Milky Way bulge and disc
area), prompted us to develop a survey strategy with five main sub-surveys that
are tailored to answer the still open questions about the assembly and
evolution of our Galaxy, while taking full advantage of the Gaia data.Comment: Part of the 4MOST issue of The Messenger, published in preparation of
4MOST Community Workshop, see http://www.eso.org/sci/meetings/2019/4MOST.htm
VE-cadherin in arachnoid and pia mater cells serves as a suitable landmark for in vivo imaging of CNS immune surveillance and inflammation.
Meninges cover the surface of the brain and spinal cord and contribute to protection and immune surveillance of the central nervous system (CNS). How the meningeal layers establish CNS compartments with different accessibility to immune cells and immune mediators is, however, not well understood. Here, using 2-photon imaging in female transgenic reporter mice, we describe VE-cadherin at intercellular junctions of arachnoid and pia mater cells that form the leptomeninges and border the subarachnoid space (SAS) filled with cerebrospinal fluid (CSF). VE-cadherin expression also marked a layer of Prox1+ cells located within the arachnoid beneath and separate from E-cadherin+ arachnoid barrier cells. In vivo imaging of the spinal cord and brain in female VE-cadherin-GFP reporter mice allowed for direct observation of accessibility of CSF derived tracers and T cells into the SAS bordered by the arachnoid and pia mater during health and neuroinflammation, and detection of volume changes of the SAS during CNS pathology. Together, the findings identified VE-cadherin as an informative landmark for in vivo imaging of the leptomeninges that can be used to visualize the borders of the SAS and thus potential barrier properties of the leptomeninges in controlling access of immune mediators and immune cells into the CNS during health and neuroinflammation
Reactivity of Sodium Pentaphospholide Na[cyclo âP 5] towards CâĄE (E=C, N, P) Triple Bonds
A diglyme solution of Na[cycloâP5] (1) reacts with alkynes and isolobal nitriles and phosphaalkynes to afford the otherwise elusive (aza)phospholide anions 2 aâc, 4 a,b, and 6. The reaction of Na[cycloâP5] with alkynes and nitriles was studied by means of DFT methods, which suggested a concerted mechanism for the formation of 2 a and 4 b. The anions 2 aâc, 4 a,b, and 6 coordinate in an η5âfashion towards FeII to give the sandwich (aza)phosphametallocenes 3 aâc, 5 a,b and 7 in moderate to good yields. The new compounds were characterized by means of multinuclear NMR spectroscopy, singleâcrystal Xâray diffraction and cyclic voltammetry
Galaxy And Mass Assembly (GAMA): the 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 m to 1 mm
We use the Galaxy And Mass Assembly survey (GAMA) I data set combined with GALEX, Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) imaging to construct the low-redshift (z < 0.1) galaxy luminosity functions in FUV, NUV, ugriz and YJHK bands from within a single well-constrained volume of 3.4 Ă 105 (Mpcâhâ1)3. The derived luminosity distributions are normalized to the SDSS data release 7 (DR7) main survey to reduce the estimated cosmic variance to the 5âper cent level. The data are used to construct the cosmic spectral energy distribution (CSED) from 0.1 to 2.1 ÎŒm free from any wavelength-dependent cosmic variance for both the elliptical and non-elliptical populations. The two populations exhibit dramatically different CSEDs as expected for a predominantly old and young population, respectively. Using the Driver et al. prescription for the azimuthally averaged photon escape fraction, the non-ellipticals are corrected for the impact of dust attenuation and the combined CSED constructed. The final results show that the Universe is currently generating (1.8 ± 0.3) Ă 1035âh W Mpcâ3 of which (1.2 ± 0.1) Ă 1035âh W Mpcâ3 is directly released into the inter-galactic medium and (0.6 ± 0.1) Ă 1035âh W Mpcâ3 is reprocessed and reradiated by dust in the far-IR. Using the GAMA data and our dust model we predict the mid- and far-IR emission which agrees remarkably well with available data. We therefore provide a robust description of the pre- and post-dust attenuated energy output of the nearby Universe from 0.1 ÎŒm to 0.6âmm. The largest uncertainty in this measurement lies in the mid- and far-IR bands stemming from the dust attenuation correction and its currently poorly constrained dependence on environment, stellar mass and morphology
An AKAP-Lbc-RhoA interaction inhibitor promotes the translocation of aquaporin-2 to the plasma membrane of renal collecting duct principal cells
Stimulation of renal collecting duct principal cells with antidiuretic hormone (arginine-vasopressin, AVP) results in inhibition of the small GTPase RhoA and the enrichment of the water channel aquaporin-2 (AQP2) in the plasma membrane. The membrane insertion facilitates water reabsorption from primary urine and fine-tuning of body water homeostasis. Rho guanine nucleotide exchange factors (GEFs) interact with RhoA, catalyze the exchange of GDP for GTP and thereby activate the GTPase. However, GEFs involved in the control of AQP2 in renal principal cells are unknown. The A-kinase anchoring protein, AKAP-Lbc, possesses GEF activity, specifically activates RhoA, and is expressed in primary renal inner medullary collecting duct principal (IMCD) cells. Through screening of 18,431 small molecules and synthesis of a focused library around one of the hits, we identified an inhibitor of the interaction of AKAP-Lbc and RhoA. This molecule, Scaff10-8, bound to RhoA, inhibited the AKAP-Lbc-mediated RhoA activation but did not interfere with RhoA activation through other GEFs or activities of other members of the Rho family of small GTPases, Rac1 and Cdc42. Scaff10-8 promoted the redistribution of AQP2 from intracellular vesicles to the periphery of IMCD cells. Thus, our data demonstrate an involvement of AKAP-Lbc-mediated RhoA activation in the control of AQP2 trafficking
Brain Abnormalities and Glioma-Like Lesions in Mice Overexpressing the Long Isoform of PDGF-A in Astrocytic Cells
BACKGROUND: Deregulation of platelet-derived growth factor (PDGF) signaling is a hallmark of malignant glioma. Two alternatively spliced PDGF-A mRNAs have been described, corresponding to a long (L) and a short (S) isoform of PDGF-A. In contrast to PDGF-A(S), the PDGF-A(L) isoform has a lysine and arginine rich carboxy-terminal extension that acts as an extracellular matrix retention motif. However, the exact role of PDGF-A(L) and how it functionally differs from the shorter isoform is not well understood.\ud
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METHODOLOGY/PRINCIPAL FINDINGS: We overexpressed PDGF-A(L) as a transgene under control of the glial fibrillary acidic protein (GFAP) promoter in the mouse brain. This directs expression of the transgene to astrocytic cells and GFAP expressing neural stem cells throughout the developing and adult central nervous system. Transgenic mice exhibited a phenotype with enlarged skull at approximately 6-16 weeks of age and they died between 1.5 months and 2 years of age. We detected an increased number of undifferentiated cells in all areas of transgene expression, such as in the subependymal zone around the lateral ventricle and in the cerebellar medulla. The cells stained positive for Pdgfr-α, Olig2 and NG2 but this population did only partially overlap with cells positive for Gfap and the transgene reporter. Interestingly, a few mice presented with overt neoplastic glioma-like lesions composed of both Olig2 and Gfap positive cell populations and with microvascular proliferation, in a wild-type p53 background.\ud
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CONCLUSIONS: Our findings show that PDGF-A(L) can induce accumulation of immature cells in the mouse brain. The strong expression of NG2, Pdgfr-α and Olig2 in PDGF-A(L) brains suggests that a fraction of these cells are oligodendrocyte progenitors. In addition, accumulation of fluid in the subarachnoid space and skull enlargement indicate that an increased intracranial pressure contributed to the observed lethality.\ud
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