370 research outputs found
First results of the CERN Resonant WISP Search (CROWS)
The CERN Resonant WISP Search (CROWS) probes the existence of Weakly
Interacting Sub-eV Particles (WISPs) like axions or hidden sector photons. It
is based on the principle of an optical light shining through the wall
experiment, adapted to microwaves. Critical aspects of the experiment are
electromagnetic shielding, design and operation of low loss cavity resonators
and the detection of weak sinusoidal microwave signals. Lower bounds were set
on the coupling constant GeV for axion like
particles with a mass of eV. For hidden sector photons, lower
bounds were set for the coupling constant at a mass
of eV. For the latter we were probing a previously
unexplored region in the parameter space
Locating, and Utilising \u3cem\u3eFestuca Pratensis\u3c/em\u3e Genes for Winter Hardiness for the Future Development of More Persistent High Quality \u3cem\u3eLolium\u3c/em\u3e Cultivars
Genes for freezing-tolerance and winter hardiness were located in Festuca pratensis by QTL analysis and introgression-mapping. QTL for freezing-tolerance on F. pratensis chromosome 4 were orthologous to rice chromosome 3, and Triticeae chromosome 5. Increased energy dissipation during the autumn through a lower maximum quantum yield of photosystem II (PSII) was correlated with improved winter survival. Freezing tolerance in Lolium was achieved by the transfer and subsequent expression of F. pratensis genes from chromosome 4 that govern the expression of a non-photochemical (NPQ) mechanism for the dissipation of excess light energy under low temperature
A New Spin on Research Translation: The Boston Consensus Conference on Human Biomonitoring
BACKGROUND. Translating research to make it more understandable and effective (research translation) has been declared a priority in environmental health but does not always include communication to the public or residents of communities affected by environmental hazards. Their unique perspectives are also commonly missing from discussions about science and technology policy. The consensus conference process, developed in Denmark, offers a way to address this gap. OBJECTIVES. The Boston Consensus Conference on Human Biomonitoring, held in Boston, Massachusetts, in the fall of 2006, was designed to educate and elicit input from 15 Boston-area residents on the scientifically complex topic of human biomonitoring for environmental chemicals. This lay panel considered the many ethical, legal, and scientific issues surrounding biomonitoring and prepared a report expressing their views. DISCUSSION. The lay panel's findings provide a distinct and important voice on the expanding use of biomonitoring. In some cases, such as a call for opt-in reporting of biomonitoring results to study participants, they mirror recommendations raised elsewhere. Other conclusions have not been heard previously, including the recommendation that an individual's results should be statutorily exempted from the medical record unless permission is granted, and the opportunity to use biomonitoring data to stimulate green chemistry. CONCLUSION. The consensus conference model addresses both aspects of a broader conception of research translation: engaging the public in scientific questions, and bringing their unique perspectives to bear on public health research, practice, and policy. In this specific application, a lay panel's recommendations on biomonitoring surveillance, communication, and ethics have practical implications for the conduct of biomonitoring studies and surveillance programs.National Institute of Environmental Health Sciences (R25 ES12084, P42ES007381
An Increasing Need for Productive and Stress Resilient Festulolium Amphiploids:What Can Be Learnt from the Stable Genomic Composition of Festuca pratensis subsp. apennina (De Not.) Hegi?
Genome composition of Festuca pratensis subsp. apennina (De Not.) Hegi, a tetraploid fescue species native to the tall forbs communities of south-eastern Europe at altitudes between 1100 and 2200m a.s.l. has been the subject of some debate by grass taxonomists. Our cytogenetic analyses including fluorescence in situ hybridisation with probes for genomic DNA and selected DNA repeats revealed the species to be allotetraploid and derived from interspecific hybridization between F. pratensis Huds., a species confined to grassland at lower altitudes, and a so far unknown Festuca species. Besides tetraploids, triploids and pentaploids were found growing in Alpine meadows in close association with F. pratensis subsp. apennina. Triploid cytotypes predominated at many sites in Switzerland and Romania, and in some localities, they were the only cytotypes observed. Cytogenetic analyses revealed the triploids to be hybrids between diploid F. pratensis and tetraploid Festuca pratensis subsp. apennina, while the pentaploid cytotypes originated from hybridization between F. pratensis subsp. apennina and hexaploid F. arundinacea Schreb., a closely-related species growing in a close vicinity to F. pratensis subsp. apennina. Parental genomes of F. pratensis subsp. apennina and of the triploid and pentaploid hybrids showed no evidence of homoeologous chromosome pairing and interspecific recombination, supporting previous observation of a disomic inheritance at meiosis, where chromosome pairing was restricted to bivalent associations. A hypothesis is presented that a chromosome pairing regulator(s), reported previously in other polyploid broad-leaved fescue species of the Festuca subg. Schedonorus, is present and functional in F. pratensis subsp. apennina. It is likely that a common ancestors’ genome that carries the chromosome pairing regulator(s) is present in all polyploid broad-leaved fescue species, and its acquisition was a key event that enabled speciation, and development of a polyploid series within Festuca. Identification of a functional chromosome pairing regulator capable of stabilizing advantageous genome combinations in hybrids within the Lolium-Festuca complex would greatly assist in development of stable Festulolium cultivars. Its expression within Festulolium amphiploid cultivars would assist strategies aimed at climate-proofing productive European grasslands to combat exposures to stress conditions
Tune shift induced by nonlinear resistive wall wake field of flat collimator
We present formulae for the coherent and incoherent tune shifts due to the nonlinear resistive wall wake field for a single beam traveling between two parallel plates. In particular, we demonstrate that the nonlinear terms of the resistive-wall wake field become important if the gap between the plates is comparable to the transverse rms beam size. We also compare the theoretically predicted tune shift as a function of gap size with measurements for an LHC prototype graphite collimator in the CERN SPS and with simulations
Studies of the Ag-In phase diagram and surface tension measurements
The phase boundaries of the Ag-In binary system were determined by the diffusion couple method, differential scanning calorimetry (DSC) and metallographic techniques. The results show that the region of the zeta (hcp) phase is narrower than that reported previously. Thermodynamic calculation of the Ag-In system is presented by taking into account the experimental results obtained by the present and previous works, including the data on the phase equilibria and thermochemical properties. The Gibbs energies of liquid and solid solution phases are described on the basis of the sub-regular solution model, and that of the intermetallic compounds are based on the two-sublattices model. A consistent set of thermodynamic parameters has been optimized for describing the Gibbs energy of each phase, which leads to a good fit between calculated and experimental results. The maximum bubble pressure method has been used to measure the surface tension and densities of liquid In, Ag, and five binary alloys in the temperature range from 227 degreesC to about 1170 degreesC. On the basis of the thermodynamic parameters of the liquid phase obtained by the present optimization, the surface tensions are calculated using Butler's model. It is shown that the calculated values of the surface tensions are in fair agreement with the experimental data
Extracellular Matrix Proteomics Reveals Interplay of Aggrecan and Aggrecanases in Vascular Remodeling of Stented Coronary Arteries.
BACKGROUND: Extracellular matrix (ECM) remodeling contributes to in-stent restenosis and thrombosis. Despite its important clinical implications, little is known about ECM changes post-stent implantation. METHODS: Bare-metal and drug-eluting stents were implanted in pig coronary arteries with an overstretch under optical coherence tomography guidance. Stented segments were harvested 1, 3, 7, 14, and 28 days post-stenting for proteomics analysis of the media and neointima. RESULTS: A total of 151 ECM and ECM-associated proteins were identified by mass spectrometry. After stent implantation, proteins involved in regulating calcification were upregulated in the neointima of drug-eluting stents. The earliest changes in the media were proteins involved in inflammation and thrombosis, followed by changes in regulatory ECM proteins. By day 28, basement membrane proteins were reduced in drug-eluting stents in comparison with bare-metal stents. In contrast, the large aggregating proteoglycan aggrecan was increased. Aggrecanases of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family contribute to the catabolism of vascular proteoglycans. An increase in ADAMTS-specific aggrecan fragments was accompanied by a notable shift from ADAMTS1 and ADAMTS5 to ADAMTS4 gene expression after stent implantation. Immunostaining in human stented coronary arteries confirmed the presence of aggrecan and aggrecan fragments, in particular, at the contacts of the stent struts with the artery. Further investigation of aggrecan presence in the human vasculature revealed that aggrecan and aggrecan cleavage were more abundant in human arteries than in human veins. In addition, aggrecan synthesis was induced on grafting a vein into the arterial circulation, suggesting an important role for aggrecan in vascular plasticity. Finally, lack of ADAMTS-5 activity in mice resulted in an accumulation of aggrecan and a dilation of the thoracic aorta, confirming that aggrecanase activity regulates aggrecan abundance in the arterial wall and contributes to vascular remodeling. CONCLUSIONS: Significant differences were identified by proteomics in the ECM of coronary arteries after bare-metal and drug-eluting stent implantation, most notably an upregulation of aggrecan, a major ECM component of cartilaginous tissues that confers resistance to compression. The accumulation of aggrecan coincided with a shift in ADAMTS gene expression. This study provides the first evidence implicating aggrecan and aggrecanases in the vascular injury response after stenting
Experimental determination and thermodynamic calculation of the phase equilibria and surface tension in the Sn-Ag-In system
The phase equilibria of the Sn-Ag-In system were investigated by means of differential scanning calorimetry (DSC) and metallography. The isothermal sections at 180-600degreesC, as well as some vertical sections, were determined. Thermodynamic assessment of this system was also carried out based on the experimental data of thermodynamic properties and phase equilibria using the calculation of phase diagram (CALPHAD) method, in which the Gibbs energies of the liquid, fcc, and hcp phases are described by the subregular solution model, and those of compounds are represented by the sublattice model. The thermodynamic parameters for describing the phase equilibria were optimized, and reasonable agreement between the calculated and experimental results was obtained. The maximum bubble-pressure method and dilatometric method have been used in measurements of the surface tension and density of the binary In-Sn and ternary (Sn-3.8Ag)(eut) + In (5 at.% and 10 at.%) liquid alloys, respectively. The experiments were performed in the temperature range from 160-930degreesC. The experimental data of the surface tension were compared with those obtained by the thermodynamic calculation of Butler's model
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