544 research outputs found
Ecology and diversity of Bacillus thuringiensis in soil environment
Bacillus thuringiensis populations ranged between 4.23 x 105, 6.52 x 105 cfu/g soil and consist of 11 types of isolates with 3 polymorphic, 7 spherical and 1 bipyramidal type of crystals. Polymorphic crystal containing isolates were further characterized. B. thuringiensis isolates were circular, white, flat and undulate or entire. These were gram-positive. These tolerated 5% NaCl and failed to grow anaerobically. None of these were positive for indole production. All were sensitive to streptomycin,vancomycin, polymyxin B and norfloxacin but resistant to penicillin G and ampicillin/sulbactum. All of the isolates were crystal forming rods, width of rods was >0.9 um, catalase positive and sporangia were not swollen. All of the isolates hydrolyzed protein but only BTc 175 produced arginine dihydrolase, BTc 152 and BTc 175 produced urease
Prompt atmospheric neutrino fluxes: perturbative QCD models and nuclear effects
We evaluate the prompt atmospheric neutrino flux at high energies using three
different frameworks for calculating the heavy quark production cross section
in QCD: NLO perturbative QCD, factorization including low-
resummation, and the dipole model including parton saturation. We use QCD
parameters, the value for the charm quark mass and the range for the
factorization and renormalization scales that provide the best description of
the total charm cross section measured at fixed target experiments, at RHIC and
at LHC. Using these parameters we calculate differential cross sections for
charm and bottom production and compare with the latest data on forward charm
meson production from LHCb at TeV and at TeV, finding good agreement
with the data. In addition, we investigate the role of nuclear shadowing by
including nuclear parton distribution functions (PDF) for the target air
nucleus using two different nuclear PDF schemes. Depending on the scheme used,
we find the reduction of the flux due to nuclear effects varies from to
at the highest energies. Finally, we compare our results with the
IceCube limit on the prompt neutrino flux, which is already providing valuable
information about some of the QCD models.Comment: 61 pages, 25 figures, 11 table
Differential Geometry for Model Independent Analysis of Images and Other Non-Euclidean Data: Recent Developments
This article provides an exposition of recent methodologies for nonparametric
analysis of digital observations on images and other non-Euclidean objects.
Fr\'echet means of distributions on metric spaces, such as manifolds and
stratified spaces, have played an important role in this endeavor. Apart from
theoretical issues of uniqueness of the Fr\'echet minimizer and the asymptotic
distribution of the sample Fr\'echet mean under uniqueness, applications to
image analysis are highlighted. In addition, nonparametric Bayes theory is
brought to bear on the problems of density estimation and classification on
manifolds
From the stable to the exotic: clustering in light nuclei
A great deal of research work has been undertaken in alpha-clustering study
since the pioneering discovery of 12C+12C molecular resonances half a century
ago. Our knowledge on physics of nuclear molecules has increased considerably
and nuclear clustering remains one of the most fruitful domains of nuclear
physics, facing some of the greatest challenges and opportunities in the years
ahead. The occurrence of "exotic" shapes in light N=Z alpha-like nuclei is
investigated. Various approaches of the superdeformed and hyperdeformed bands
associated with quasimolecular resonant structures are presented. Evolution of
clustering from stability to the drip-lines is examined: clustering aspects
are, in particular, discussed for light exotic nuclei with large neutron excess
such as neutron-rich Oxygen isotopes with their complete spectroscopy.Comment: 15 pages, 5 figures, Presented at the International Symposium on "New
Horizons in Fundamental Physics - From Neutrons Nuclei via Superheavy
Elements and Supercritical Fields to Neutron Stars and Cosmic Rays" held at
Makutsi Safari Farm, South Africa, December 23-29, 2015. arXiv admin note:
substantial text overlap with arXiv:1402.6590, arXiv:1303.0960,
arXiv:1408.0684, arXiv:1011.342
How managers can build trust in strategic alliances: a meta-analysis on the central trust-building mechanisms
Trust is an important driver of superior alliance performance. Alliance managers are influential in this regard because trust requires active involvement, commitment and the dedicated support of the key actors involved in the strategic alliance. Despite the importance of trust for explaining alliance performance, little effort has been made to systematically investigate the mechanisms that managers can use to purposefully create trust in strategic alliances. We use Parkhe’s (1998b) theoretical framework to derive nine hypotheses that distinguish between process-based, characteristic-based and institutional-based trust-building mechanisms. Our meta-analysis of 64 empirical studies shows that trust is strongly related to alliance performance. Process-based mechanisms are more important for building trust than characteristic- and institutional-based mechanisms. The effects of prior ties and asset specificity are not as strong as expected and the impact of safeguards on trust is not well understood. Overall, theoretical trust research has outpaced empirical research by far and promising opportunities for future empirical research exist
Correlators of Giant Gravitons from dual ABJ(M) Theory
We generalize the operators of ABJM theory, given by Schur polynomials, in
ABJ theory by computing the two point functions in the free field and at finite
limits. These polynomials are then identified with the states of
the dual gravity theory. Further, we compute correlators among giant gravitons
as well as between giant gravitons and ordinary gravitons through the
corresponding correlators of ABJ(M) theory. Finally, we consider a particular
non-trivial background produced by an operator with an -charge of
and find, in presence of this background, due to the contribution of
the non-planar corrections, the large expansion is replaced by
and respectively.Comment: Latex, 32+1 pages, 2 figures, journal versio
BioCreative III interactive task: an overview
The BioCreative challenge evaluation is a community-wide effort for evaluating text mining and information extraction systems applied to the biological domain. The biocurator community, as an active user of biomedical literature, provides a diverse and engaged end user group for text mining tools. Earlier BioCreative challenges involved many text mining teams in developing basic capabilities relevant to biological curation, but they did not address the issues of system usage, insertion into the workflow and adoption by curators. Thus in BioCreative III (BC-III), the InterActive Task (IAT) was introduced to address the utility and usability of text mining tools for real-life biocuration tasks. To support the aims of the IAT in BC-III, involvement of both developers and end users was solicited, and the development of a user interface to address the tasks interactively was requested
ZipA Binds to FtsZ with High Affinity and Enhances the Stability of FtsZ Protofilaments
A bacterial membrane protein ZipA that tethers FtsZ to the membrane is known to promote FtsZ assembly. In this study, the binding of ZipA to FtsZ was monitored using fluorescence spectroscopy. ZipA was found to bind to FtsZ with high affinities at three different (6.0, 6.8 and 8.0) pHs, albeit the binding affinity decreased with increasing pH. Further, thick bundles of FtsZ protofilaments were observed in the presence of ZipA under the pH conditions used in this study indicating that ZipA can promote FtsZ assembly and stabilize FtsZ polymers under unfavorable conditions. Bis-ANS, a hydrophobic probe, decreased the interaction of FtsZ and ZipA indicating that the interaction between FtsZ and ZipA is hydrophobic in nature. ZipA prevented the dilution induced disassembly of FtsZ polymers suggesting that it stabilizes FtsZ protofilaments. Fluorescein isothiocyanate-labeled ZipA was found to be uniformly distributed along the length of the FtsZ protofilaments indicating that ZipA stabilizes FtsZ protofilaments by cross-linking them
Cost-Effectiveness Analysis of Combination Therapies for Visceral Leishmaniasis in the Indian Subcontinent
Visceral leishmaniasis (VL) is a serious health problem in the Indian subcontinent affecting the rural poor. It has a significant economic impact on concerned households. The development of drug resistance is a major problem and threatens control efforts under the VL elimination initiative. With an unprecedented choice of antileishmanial drugs (but no newer compound in clinical development), policies that protect these drugs against the emergence of resistance are required. A possible strategy that has been successfully used for malaria and tuberculosis is the use of combination therapies. This study is the first comprehensive assessment of the cost-effectiveness of all possible mono- and combination therapies for the treatment of visceral leishmaniasis in the Indian subcontinent. The analysis was done from the societal perspective, including both health provider and household costs. The present work shows that combination treatments are a cost-effective alternative to current monotherapy for VL. Given their expected impact on emergence of drug resistance, the use of combination therapy should be considered in the context of the VL elimination programme in the Indian subcontinent
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