1,427 research outputs found
The detection of Melissococcus pluton in honey bees (Apis mellifera) and their products using a hemi-nested PCR
A hemi-nested polymerase chain reaction (PCR) was further developed for the detection of Melissococcus pluton in adult bees and honey bee products. A chloroform:isoamyl alcohol DNA extraction method was used to provide template from 154 samples of adult bee tissues, honey, pollen, whole larvae and comb cells. All 36 honey bee samples tested from a diseased colony were shown to contain M. pluton and sub-clinical infections were detected in adult bee tissues, larvae and honey (49/98; 50.0%) collected from all 9 healthy colonies from areas where EFB was endemic. All 20 adult bee tissue samples from a healthy colony from Western Australia where EFB has never been reported were negative. Of 80 bulk honey samples from six Australian states, 55 of 80 (68.8%) samples were shown to contain M. pluton whereas culture techniques detected M. pluton in 22 of 80 (27.5%) of these samples. M. pluton was detected in honey from all Australian states except Western Australia
Resilience to cope with climate change in urban areas - A multisectorial approach focusing on water - The RESCCUE project
This is the final version. Available on open access from MDPI via the DOI in this recordThe RESCCUE Project is an H2020 research project that aims to help cities around the world to become more resilient to physical, social, and economic challenges, using the water sector as the central point of the approach. RESCCUE will generate models and tools to bring this objective to practice, while delivering a framework enabling city resilience assessment, planning and management. This will be achieved by integrating software tools, methods, and new knowledge related to the detailed urban services performance into novel and promising loosely coupled models (integrated models), multi-risk assessment method, and a comprehensive resilience platform. These tools will allow urban resilience assessment from a multisectorial approach, for current and future climate change scenarios, including multiple hazards and cascading effects. The RESCCUE approach will be implemented in three EU cities (Barcelona, Bristol, and Lisbon) and, with the support of UN-Habitat, disseminate their results among other cities belonging to major international networks. The aim of this paper is to present the main goals of this project, as well as the approach followed and the main expected results after the four years of implementation, so other cities around the world can use the RESCCUE approach to increase their resilience.The RESCCUE Project (RESilience to cope with Climate Change in Urban arEas—a multisectorial approach focusing on water) has received funding from European Commission by means of Horizon 2020, the EU Framework Program for Research and Innovation, under Grant Agreement No. 700174
Investigation of exchange coupled bilayer Fe/CuMnAs by pump-probe experiment
Time-resolved pump-probe magneto-optical method was used to study Fe/CuMnAs bilayer. The probe polarization dependence was used to identify and separate parts of detected signals due to Faraday and Voigt magneto-optical effects that provide information about pump-induced magnetization precession in ferromagnetic (FM) Fe and demagnetization in antiferromagnetic (AF) CuMnAs layers, respectively. We observed a 180 deg phase shift in the precession signal at non-zero magnetic field that we interpreted as a signature of the magnetic anisotropy induced in the FM by the adjacent AF layer. Unlike in x-ray magnetic linear dichroism experiments, we did not observe any significant reorientation of magnetic moments in CuMnAs by external magnetic field due to the interlayer exchange coupling with Fe. Differences between these two experimental techniques, providing the distinct pictures, are discussed
Corrections to scaling in 2--dimensional polymer statistics
Writing for the mean
square end--to--end length of a self--avoiding polymer chain of
links, we have calculated for the two--dimensional {\em continuum}
case from a new {\em finite} perturbation method based on the ground state of
Edwards self consistent solution which predicts the (exact) exponent.
This calculation yields . A finite size scaling analysis of data
generated for the continuum using a biased sampling Monte Carlo algorithm
supports this value, as does a re--analysis of exact data for two--dimensional
lattices.Comment: 10 pages of RevTex, 5 Postscript figures. Accepted for publication in
Phys. Rev. B. Brief Reports. Also submitted to J. Phys.
Mach Cones in Quark Gluon Plasma
The experimental azimuthal dihadron distributions at RHIC show a double peak
structure in the away side ( rad.) for intermediate
particles. A variety of models have appeared trying to describe this
modification. We will review most of them, with special emphasis in the Conical
Flow scenario in which the observed shape is a consequence of the emission of
sound by a supersonic high momentum particle propagating in the Quark Gluon
Plasma.Comment: 8 pages, 3 figures, Invited plenary talk given at the 19th
International Conference on Ultrarelativistic Nucleus-Nucleus Collisions:
Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 200
In Silico Insights into the Symbiotic Nitrogen Fixation in Sinorhizobium meliloti via Metabolic Reconstruction
BACKGROUND: Sinorhizobium meliloti is a soil bacterium, known for its capability to establish symbiotic nitrogen fixation (SNF) with leguminous plants such as alfalfa. S. meliloti 1021 is the most extensively studied strain to understand the mechanism of SNF and further to study the legume-microbe interaction. In order to provide insight into the metabolic characteristics underlying the SNF mechanism of S. meliloti 1021, there is an increasing demand to reconstruct a metabolic network for the stage of SNF in S. meliloti 1021. RESULTS: Through an iterative reconstruction process, a metabolic network during the stage of SNF in S. meliloti 1021 was presented, named as iHZ565, which accounts for 565 genes, 503 internal reactions, and 522 metabolites. Subjected to a novelly defined objective function, the in silico predicted flux distribution was highly consistent with the in vivo evidences reported previously, which proves the robustness of the model. Based on the model, refinement of genome annotation of S. meliloti 1021 was performed and 15 genes were re-annotated properly. There were 19.8% (112) of the 565 metabolic genes included in iHZ565 predicted to be essential for efficient SNF in bacteroids under the in silico microaerobic and nutrient sharing condition. CONCLUSIONS: As the first metabolic network during the stage of SNF in S. meliloti 1021, the manually curated model iHZ565 provides an overview of the major metabolic properties of the SNF bioprocess in S. meliloti 1021. The predicted SNF-required essential genes will facilitate understanding of the key functions in SNF and help identify key genes and design experiments for further validation. The model iHZ565 can be used as a knowledge-based framework for better understanding the symbiotic relationship between rhizobia and legumes, ultimately, uncovering the mechanism of nitrogen fixation in bacteroids and providing new strategies to efficiently improve biological nitrogen fixation
The p53HMM algorithm: using profile hidden markov models to detect p53-responsive genes
<p>Abstract</p> <p>Background</p> <p>A computational method (called p53HMM) is presented that utilizes Profile Hidden Markov Models (PHMMs) to estimate the relative binding affinities of putative p53 response elements (REs), both p53 single-sites and cluster-sites. These models incorporate a novel "Corresponded Baum-Welch" training algorithm that provides increased predictive power by exploiting the redundancy of information found in the repeated, palindromic p53-binding motif. The predictive accuracy of these new models are compared against other predictive models, including position specific score matrices (PSSMs, or weight matrices). We also present a new dynamic acceptance threshold, dependent upon a putative binding site's distance from the Transcription Start Site (TSS) and its estimated binding affinity. This new criteria for classifying putative p53-binding sites increases predictive accuracy by reducing the false positive rate.</p> <p>Results</p> <p>Training a Profile Hidden Markov Model with corresponding positions matching a combined-palindromic p53-binding motif creates the best p53-RE predictive model. The p53HMM algorithm is available on-line: <url>http://tools.csb.ias.edu</url></p> <p>Conclusion</p> <p>Using Profile Hidden Markov Models with training methods that exploit the redundant information of the homotetramer p53 binding site provides better predictive models than weight matrices (PSSMs). These methods may also boost performance when applied to other transcription factor binding sites.</p
Distribution of Class 1 Integrons with IS26-Mediated Deletions in Their 3′-Conserved Segments in Escherichia coli of Human and Animal Origin
Class 1 integrons play a role in the emergence of multi-resistant bacteria by facilitating the recruitment of gene cassettes encoding antibiotic resistance genes. 512 E. coli strains sourced from humans (n = 202), animals (n = 304) and the environment (n = 6) were screened for the presence of the intI1 gene. In 31/79 integron positive E. coli strains, the gene cassette regions could not be PCR amplified using standard primers. DNA sequence analysis of 6 serologically diverse strains revealed atypical integrons harboured the dfrA5 cassette gene and only 24 bp of the integron 3′-conserved segment (CS) remained, due to the insertion of IS26. PCR targeting intI1 and IS26 followed by restriction fragment length polymorphism (RFLP) analysis identified the integron-dfrA5-IS26 element in 27 E. coli strains of bovine origin and 4 strains of human origin. Southern hybridization and transformation studies revealed the integron-dfrA5-IS26 gene arrangement was either chromosomally located or plasmid borne. Plasmid location in 4/9 E. coli strains and PCR linkage of Tn21 transposition genes with the intI1 gene in 20/31 strains, suggests this element is readily disseminated by horizontal transfer
Thermal Dileptons at LHC
We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb
collisions at LHC. Hadronic emission in the low-mass region is calculated using
in-medium spectral functions of light vector mesons within hadronic many-body
theory. In the intermediate-mass region thermal radiation from the Quark-Gluon
Plasma, evaluated perturbatively with hard-thermal loop corrections, takes
over. An important source over the entire mass range are decays of correlated
open-charm hadrons, rendering the nuclear modification of charm and bottom
spectra a critical ingredient.Comment: 2 pages, 2 figures, contributed to Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun
2007 v2: acknowledgment include
Feasibility and safety of high-dose adenosine perfusion cardiovascular magnetic resonance
<p>Abstract</p> <p>Introduction</p> <p>Adenosine is the most widely used vasodilator stress agent for Cardiovascular Magnetic Resonance (CMR) perfusion studies. With the standard dose of 140 mcg/kg/min some patients fail to demonstrate characteristic haemodynamic changes: a significant increase in heart rate (HR) and mild decrease in systolic blood pressure (SBP). Whether an increase in the rate of adenosine infusion would improve peripheral and, likely, coronary vasodilatation in those patients is unknown. The aim of the present study was to assess the tolerance and safety of a high-dose adenosine protocol in patients with inadequate haemodynamic response to the standard adenosine protocol when undergoing CMR perfusion imaging.</p> <p>Methods</p> <p>98 consecutive patients with known or suspected coronary artery disease (CAD) underwent CMR perfusion imaging at 1.5 Tesla. Subjects were screened for contraindications to adenosine, and an electrocardiogram was performed prior to the scan. All patients initially received the standard adenosine protocol (140 mcg/kg/min for at least 3 minutes). If the haemodynamic response was inadequate (HR increase < 10 bpm or SBP decrease < 10 mmHg) then the infusion rate was increased up to a maximum of 210 mcg/kg/min (maximal infusion duration 7 minutes).</p> <p>Results</p> <p>All patients successfully completed the CMR scan. Of a total of 98 patients, 18 (18%) did not demonstrate evidence of a significant increase in HR or decrease in SBP under the standard adenosine infusion rate. Following the increase in the rate of infusion, 16 out of those 18 patients showed an adequate haemodynamic response. One patient of the standard infusion group and two patients of the high-dose group developed transient advanced AV block. Significantly more patients complained of chest pain in the high-dose group (61% vs. 29%, p = 0.009). On multivariate analysis, age > 65 years and ejection fraction < 57% were the only independent predictors of blunted haemodynamic responsiveness to adenosine.</p> <p>Conclusions</p> <p>A substantial number of patients do not show adequate peripheral haemodynamic response to standard-dose adenosine stress during perfusion CMR imaging. Age and reduced ejection fraction are predictors of inadequate response to standard dose adenosine. A high-dose adenosine protocol (up to 210 mcg/kg/min) is well tolerated and results in adequate haemodynamic response in nearly all patients.</p
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