1,161 research outputs found
Confronting Instanton Perturbation Theory with QCD Lattice Results
We exploit a recent lattice investigation (UKQCD) on the topological
structure of the (quenched) QCD vacuum, in order to gain information on crucial
building blocks of instanton perturbation theory. A central motivation is to
further constrain our previous predictions of instanton-induced hard scattering
processes. First, we address the generic problem of extracting quantitative
information from cooled lattice data. We find a new scaling variable,
interpreted as a "cooling radius", which allows to combine lattice data for a
whole range of lattice spacings and cooling sweeps. This variable strongly
helps to extract information on the uncooled distributions of interest. After
performing the continuum extrapolation of the instanton size and
instanton-anti-instanton distance distributions, we find striking agreement
with the theoretical predictions from instanton-perturbation theory, for
instanton sizes below 0.5 fm and distances above 0.5 fm, respectively. These
results imply first direct support for the validity of the known valley
interaction between instantons and anti-instantons.Comment: 14 pages, 6 figures, submitted to Physics Letters
Dynamiques rurales et développement régional dans la province Nord de Nouvelle-Calédonie
Dans le contexte de transition institutionnelle que connaissent le Territoire et la Province Nord, le Programme Agricultures familiales du CIRAD-Tera a réalisé une étude de diagnostic sur les dynamiques rurales et le développement régional dans la Province Nord à la demande de la Direction du développement rural et de la pêche (DDRP). Ce diagnostic, conduit en étroite collaboration avec les agents et responsables de la DDRP, repose sur une approche globale des activités agricoles et non agricoles des ruraux combinant : - une analyse sectorielle mettant en évidence les enseignements et les limites des approches "filières" ;- une analyse des stratégies individuelles, des activités et des revenus des ruraux - une approche des dynamiques collectives : organisations professionnelles, dynamiques associatives et territoriales ;- une approche de la diversité des situations et des dynamiques territoriales en Province Nord.Le diagnostic débouche sur des propositions susceptibles de renforcer la construction d'un projet de développement régional de la Province Nord en cohérence avec l'élaboration d'un projet territorial. Se fondant sur une appréciation des atouts de la Province, les propositions opérationnelles sont structurées autour de trois axes : - le renforcement des positions provinciales sur les marchés territoriaux- l'élargissement du marché provincial ;- la promotion des approches de développement local. Le développement de ces trois axes suppose que des appuis adaptés soient apportés pour renforcer les capacités d'analyse et de négociation des acteurs locaux. Au plan opérationnel, la mise en oeuvre d'un conseil de gestion global pour l'appui aux exploitations agricoles et d'un dispositif d'accompagnement des dynamiques de développement local apparaissent comme des priorités
Boundary Yang-Baxter equation in the RSOS/SOS representation
We construct and solve the boundary Yang-Baxter equation in the RSOS/SOS
representation. We find two classes of trigonometric solutions; diagonal and
non-diagonal. As a lattice model, these two classes of solutions correspond to
RSOS/SOS models with fixed and free boundary spins respectively. Applied to
(1+1)-dimenional quantum field theory, these solutions give the boundary
scattering amplitudes of the particles. For the diagonal solution, we propose
an algebraic Bethe ansatz method to diagonalize the SOS-type transfer matrix
with boundary and obtain the Bethe ansatz equations.Comment: 30 pages, 5 figures, uses Latex with eepic.sty and epic.sty. Paper
substantially expanded; section on SOS model is revised and a new section on
the Bethe ansatz equation is adde
Organic chemistry of NH<sub>3</sub> and HCN induced by an atmospheric abnormal glow discharge in N<sub>2</sub>-CH<sub>4</sub> mixtures
The formation of the chemical products produced in an atmospheric glow discharge fed by a N2-CH4 gas mixture has been studied using Fourier Transform InfraRed (FTIR) and Optical Emission Spectrometry (OES). The measurements were carried out in a flowing regime at ambient temperature and pressure with CH4 concentrations ranging from 0.5% to 2%. In the recorded emission spectra the lines of the second positive system CN system and the first negative system of N2 were found to be the most intensive but atomic Hα, Hβ, and C (247 nm) lines were also observed. FTIR-measurements revealed HCN
and NH3 to be the major products of the plasma with traces of C2H2. These same molecules have been detected in Titan's atmosphere and the present experiments may provide some novel insights into the
chemical and physical mechanisms prevalent in Titan's atmosphere with these smaller species believed to be the precursors of heavier organic species in Titan's atmosphere and on its surface
The CRISPR/Cas9 System for Crop Improvement: Progress and Prospects
The global demand for high-quality crops is continuously growing with time. Crop improvement techniques have a long history and they had been applied since the beginning of domestication of the first agricultural plants. Since then, various new techniques have and are being developed to further increase the commercial value and yield of crops. The latest crop improvement technique known as genome editing is a technique that enables precise modification of the plant genome via knocking out undesirable genes or enabling genes to gain new function. The variants generated from the genome editing are indistinguishable from naturally occurring variation. It is also less time-consuming and more readily accepted in the market commercially. The usage of genome editing has proven to be advantages and plays a promising role in future crop improvement efforts. Therefore, in this chapter, we aim to highlight the progress and application of genome editing techniques, in particular, the CRISPR/Cas9 system as a powerful genome editing tool for crop improvement. In addition, the challenges and future prospects of this technology for crop improvement will also be discussed
Cardiovascular Outcomes in Trials of New Antidiabetic Drug Classes
Type 2 diabetes is among the most prevalent chronic diseases worldwide and the prevention of associated cardiovascular complications is an important treatment goal. Sodium–glucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are second-line options after metformin, while cardiovascular outcome trials have been conducted to establish the cardiovascular safety of these antidiabetic drug classes. SGLT2 inhibitors have been shown to have the best overall mortality, renal and cardiovascular outcomes. Reduction in hospitalisation for heart failure is particularly consistent. GLP-1 receptor agonists have also showed some benefits, especially in stroke prevention. DPP-4 inhibitors showed neutral effects on cardiovascular outcomes, but may increase the incidence of heart failure. Favourable outcomes observed in trials of SGLT2 inhibitors mean that these should be the preferred second-line option. DPP-4 inhibitors are useful for patients with diabetes at low cardiovascular risk
Microwave and Millimeter Wave Techniques
Contains reports on four research projects.Joint Services Electronics Program (Contract DAAB07-74-C-0630)National Science Foundation (Grant MPS-73-05043-A01
Vacuum structure and high-energy scattering
This short review deals with the manifestations of the vacuum structure of
non-Abelian gauge theories in high-energy scattering. Specifically, it
concentrates on instanton-induced hard scattering processes, both in the
electroweak gauge theory and in QCD. Soft scattering processes in QCD and their
connection to models of semi-hard vacuum fluctuations are also briefly
discussed.Comment: 5 pages, 5 figures, espcrc2.sty (included), talk presentet at QCD 02,
Montpellier, France, July 2-9, 200
0098: Erythrocyte membrane phospholipid fatty acids, dairy intakes and cardiovascular risk
IntroductionThe impact of dairy fats on cardiovascular risk has been debated. Circulating Pentadecanoic (15:0) and heptadecanoic (17:0) saturated fatty acids are good biomarkers of dairy product consumption as they are mainly provided by dairy fats. We described the prevalence of cardiovascular risk factors according to erythrocyte membrane phospholipid content in 15:0 and 17:0 fatty acids.Methods402 women and men aged 45-64 were randomly selected in 2005-2007, from the general population of three French areas. Nutritional data were collected through a 3-day food record. Fatty acid content was measured in erythrocyte membrane phospholipids.ResultsErythrocyte membrane contents in 15:0 and 17:0 fatty acids significantly increased with the consumption of dairy products collected during the 3-day food record. Prevalence of hypertension significantly decreased from the lowest to the highest quartile of 15:0 erythrocyte content (48.1%; 33.3%; 29.9%; 25.5%; p=0.005). A similar trend was observed for metabolic syndrome prevalence (39.4%; 28.1%; 25.2%; 21.3%; p=0.029). Prevalence of hypertension, hypertriglyceridaemia, overweight and metabolic syndrome significantly decreased from the lowest to the highest quartile of 17:0 erythrocyte content (44.1%; 36.5%; 28.1%; 25.6%; p=0.020 for hypertension; 30.3%; 15.4%; 16.9%; 16.7%; p=0.017 for hypertriglyceridaemia; 68.1%; 58.7%; 46.6%; 44.4%; p=0.002 for overweight; and 43.2%; 26.9%; 22.5%; 17.8%; p<0.001 for metabolic syndrome). All these relationships remained significant after adjustment for age and gender. The link did not reach significance level for diabetes.ConclusionElevated erythrocyte membrane phospholipid contents in 15:0 and 17:0 saturated fatty acids are associated with a lower prevalence of the metabolic syndrome and several of its components. These results suggest that saturated fat intake should not be systematically associated with high cardiovascular risk and can be considered as part of a balanced diet
Radio Astronomy
Contains reports on four research projects.National Aeronautics and Space Administration (Grant NGL 22-009-016)National Aeronautics and Space Administration (Grant NGR 22-009-421)National Science Foundation (Grant GP-20769)National Science Foundation (Grant GP-21348)California Institute of Technology Contract 952568Sloan Fund for Basic Research (M. I. T. Grant 241
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