494 research outputs found
What I Have Learned from 4 Years of Alfalfa Grazing Tolerance Variety Trials
There has been interest in alfalfa varieties that would tolerate grazing for some time. The spreading type alfalfas (such as Rambler, Spredor 2, Travois) have long been generally promoted as being tolerant of grazing. Over the years, most selection for tolerance to grazing was done using frequent clipping to simulate grazing.
Studies conducted at the University of Georgia in the 1980\u27s found that alfalfa varieties performed differently when grazed frequently compared to clipping frequently. This line of research eventually led to the release of \u27AlfaGraze\u27 alfalfa which was the first variety ever to be selected primarily by overgrazing by livestock. The advent of this variety and others soon after raised the need for verification of grazing tolerance under Kentucky conditions
The Cozzo Disi mine (Casteltermini, Sicily, Italy) a multi-disciplinary approach to record, study, preserve and develop the mining heritage in Sicily
Cozzo Disi was one of the main sulphur mines in Italy, but after the closure and more than 10 years of desertion,
urgent works are now necessary to save it from vandalism and flooding. This big mine contains geological and
mineralogical peculiarities, so uncommon to be sometimes unique: this is the case of the \u201cGrandi Garbere\u201d at 3rd
level, majestic karst cavities, containing magnificent selenite crystals documented by old miners. The possibility
to have a \u201cSicilian Naica\u201d attracted a multi-disciplinary underground task-force, now exploring the mine
underground, in order to inspect old works and their good-safety conditions, and to achieve the rooms/caves of
\u201cGrandi Garbere\u201d. This extraordinary discovery should be relevant for the future of this territory. In the past, the
mine was characterized by huge safety problems: hydrogen sulfide, carbon dioxide and explosive atmospheres; so,
the team involved in actual and future explorations has to move with caution, using adequate equipment and - if
necessary - waiting for acceptable environmental conditions created by artificial tools (ventilation, pumping, etc.)
Atorvastatin combined to interferon to verify the efficacy (ACTIVE) in relapsing-remitting active multiple sclerosis patients: a longitudinal controlled trial of combination therapy.
A large body of evidence suggests that, besides their cholesterol-lowering effect, statins exert anti-inflammatory action. Consequently, statins may have therapeutic potential in immune-mediated disorders such as multiple sclerosis. Our objectives were to determine safety, tolerability and efficacy of low-dose atorvastatin plus high-dose interferon beta-1a in multiple sclerosis patients responding poorly to interferon beta-1a alone. Relapsingâremitting multiple sclerosis patients, aged 18â50 years, with contrast-enhanced lesions or relapses while on therapy with interferon beta-1a 44 mg (three times weekly) for 12 months, were randomized to combination therapy (interferon+atorvastatin 20mg per day; group A) or interferon alone (group B) for 24 months. Patients underwent blood analysis and clinical assessment with the Expanded Disability Status Scale every 3 months, and brain gadolinium-enhanced magnetic resonance imaging at screening, and 12 and 24 months thereafter. Primary outcome measure was contrast-enhanced lesion number. Secondary outcome measures were number of relapses, EDSS variation and safety laboratory data. Forty-five patients were randomized to group A (n 1â4 21) or B (n 1â4 24). At 24 months, group A had significantly fewer contrast-enhanced lesions versus baseline (p 1â4 0.007) and significantly fewer relapses versus the two pre-randomization years (p < 0.001). At survival analysis, the risk for a 1-point EDSS increase was slightly higher in group B than in group A (p 1â4 0.053). Low-dose atorvastatin may be beneficial, as add-on therapy, in poor responders to high-dose interferon beta-1a alone
8Li+alpha decay of 12B and its possible astrophysical implications
The 12B excitation energy spectrum has been obtained from coincidence
measurements of the 9Be+7Li -> 2alpha+8Li reaction at E{0}=52 MeV.
The decay of the states at excitations between 10 and 16 Mev into alpha$+8Li
has been observed for the first time. Observed alpha-decay indicates possible
cluster structure of the 12B excited states.
The influence of these states on the cross section of the astrophysically
important 8Li(alpha,n)11B and 9Be+t reactions is discussed and the results are
compared with existing results.Comment: accepted for publication in Europhysics Letter
Evaluating Varieties of Alfalfa and Tall Fescue for Tolerance to Over-Grazing by Cattle
Cultivars of alfalfa (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb.) were seeded in small (1.5 m x 4.6 m) plots and harvested for estimating yield the following spring. Plots were then grazed by cattle continuously for the remainder of the season so as to keep stand heights at 7.5 cm or less. This procedure was repeated for one or two more grazing seasons, depending on stand survival. Stands were visually rated for stand in the fall and spring. Marked differences in grazing tolerance were observed among alfalfa cultivars, following closely the commercial designations as grazing-type or hay-type alfalfa. Some cultivars of endophyte-free tall fescue were as grazing tolerant as endophyte-infected Kentucky 31 tall fescue
Trojan Horse as an indirect technique in nuclear astrophysics. Resonance reactions
The Trojan Horse method is a powerful indirect technique that provides
information to determine astrophysical factors for binary rearrangement
processes at astrophysically relevant energies by measuring
the cross section for the Trojan Horse reaction in
quasi-free kinematics. We present the theory of the Trojan Horse method for
resonant binary subreactions based on the half-off-energy-shell R matrix
approach which takes into account the off-energy-shell effects and initial and
final state interactions.Comment: 6 pages and 1 figur
Determination of the photodisintegration reaction rates involving charged particles: systematical calculations and proposed measurements based on Extreme Light Infrastructure - Nuclear Physics (ELI-NP)
Photodisintegration reaction rates involving charged particles are of
relevance to the p-process nucleosynthesis that aims at explaining the
production of the stable neutron-deficient nuclides heavier than iron. In this
study, the cross sections and astrophysical rates of (g,p) and (g,a) reactions
for about 3000 target nuclei with 10<Z<100 ranging from stable to proton
dripline nuclei are computed. To study the sensitivity of the calculations to
the optical model potentials (OMPs), both the phenomenological Woods-Saxon and
the microscopic folding OMPs are taken into account. The systematic comparisons
show that the reaction rates, especially for the (g,a) reaction, are
dramatically influenced by the OMPs. Thus the better determination of the OMP
is crucial to reduce the uncertainties of the photodisintegration reaction
rates involving charged particles. Meanwhile, a gamma-beam facility at ELI-NP
is being developed, which will open new opportunities to experimentally study
the photodisintegration reactions of astrophysics interest. Considering both
the important reactions identified by the nucleosynthesis studies and the
purpose of complementing the experimental results for the reactions involving
p-nuclei, the measurements of six (g,p) and eight (g,a) reactions based on the
gamma-beam facility at ELI-NP and the ELISSA detector for the charged particles
detection are proposed, and the GEANT4 simulations are correspondingly
performed. The minimum required energies of the gamma-beam to measure these
reactions are estimated. It is shown that the direct measurements of these
photonuclear reactions within the Gamow windows at T_9=2.5 for p-process are
fairly feasible and promising at ELI-NP. The expected experimental results will
be used to constrain the OMPs of the charged particles, which can eventually
reduce the uncertainties of the reaction rates for the p-process
nucleosynthesis.Comment: 14 pages, 8 figures, Phys. Rev. C accepte
Migraine and Cranial Autonomic Symptoms in Children and Adolescents: A Clinical Study
The frequency of cranial autonomic symptoms in children affected by primary headaches is uncertain. The aim of our study was to estimate the frequency of symptoms in pediatric headaches and correlate it with main migraine characteristics. A questionnaire investigating the presence of cranial autonomic symptoms was administered to all children with primary headache for 2 years. A total of 230 children with primary headache (105 males, 125 females) were included. Two hundred two children were affected by migraine and 28 (12.2%) by other primary headaches. Cranial autonomic symptoms were significantly complained by migraineurs (55% vs 17.8%) (P < .001) and by children with higher frequency of migraine attacks (odds ratio = 2.6, confidence interval = 1.4-4.7, P = .001). Our findings show that cranial autonomic symptoms are rather common during pediatric migraine attacks. The association between cranial autonomic symptoms and higher frequency of attacks might suggest the role of the trigeminal-autonomic reflex in migraine pathophysiolog
Prompt electrons driving ion acceleration and formation of a two temperatures plasma in nanosecond laser-ablation domain
We present the results of an experiment on plasma generation via laser
ablation at 10^12 W/cm^2 of power intensity and in a nanosecond domain. Prompt
electrons emission and complex plasma plume fragmentation were simultaneously
observed for the first time in this laser intensity regime, along with a double
electron temperature inside the plasma bulk surviving for a long time to the
plume expansion. 1D PIC simulations are in agreement with experimental data as
long as the emission of initial prompt electrons is considered. This assumption
results to be the key to explain all the other experimental evidences.Comment: 5 pages, 6 figures, Europhysics Letters in pres
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