64 research outputs found
Observations and Simulations of Electron Dynamics Near an Active Neutral Line
Recent observations in the Earth's magnetotail have shown rapid increases in the fluxes of energetic electrons with energies up to 100's of keV associated with dipolarization fronts that propagate into the inner magnetosphere. On August 15, 2001 the four Cluster spacecraft located slightly dawnward of midnight (yGSM approx. -5.4RE) at xGSM approx. -18RE observed a series of earthward propagating dipolarization fronts [Hwang et al., 2010]. At least 6 dipolarization fronts were observed in a 20m interval. Unlike previously reported cases the fluxes of electrons up to 95keV decreased during the passage of the first three fronts over the spacecraft. The energetic electron fluxes increased during the passage of the last three fronts. We have performed a global magnetohydrodynamic simulation of this event using solar wind observations from the ACE satellite to drive the simulation. In the simulation a very complex reconnection system in the near-Earth tail at XGSM approx. -20RE launched a series of earthward propagating dipolarization fronts that are similar to those observed on Cluster. The simulation results indicate that the Cluster spacecraft were just earthward of the reconnection site. In this paper we will present a study of the dynamics of electrons associated with these events by using the large-scale kinetic simulation approach in which we launch a large number of electrons into the electric and magnetic fields from this simulation
Effects of plyometric and short sprint with change-of-direction training in male U17 soccer players
This project investigated the effect of adding 8 weeks of bi-weekly plyometric and short sprint with change-of-direction (PSSCoD) training into standard training for elite youth soccer players from Tunisia. A training group (n = 18; age: 16.6 ± 0.5 years; body mass: 63.2 ± 4.8 kg; stature: 1.73 ± 0.07 m; body fat: 11.2 ± 1.7%), and control group (n = 16; age: 16.6 ± 0.5 years; body mass: 63.6 ± 4.3 kg; height: 1.73 ± 0.06 m; body fat: 11.6 ± 1.5%) participated. The pre- and post-intervention measures were squat-jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), 5 m and 20 m sprint, change-of-direction ability (4 × 5 m sprint test (S 4 × 5 m)), repeated sprint ability (RSA), and static balance (stork balance test). The training group displayed superior jump (all p < 0.05; d > 0.49), sprint (p < 0.05; d > 0.52), change-of-direction ability (p < 0.01; d = 0.78), RSA (p < 0.01; d > 0.70), and static balance (p < 0.05; d > 0.49) improvements. Adding bi-weekly PSSCoD improves the athletic performance of young soccer players
Effects of Plyometric and Short Sprint with Change-of-Direction Training in Male U17 Soccer Players
This project investigated the effect of adding 8 weeks of bi-weekly plyometric and short sprint with change-of-direction (PSSCoD) training into standard training for elite youth soccer players from Tunisia. A training group (n = 18; age: 16.6 ± 0.5 years; body mass: 63.2 ± 4.8 kg; stature: 1.73 ± 0.07 m; body fat: 11.2 ± 1.7%), and control group (n = 16; age: 16.6 ± 0.5 years; body mass: 63.6 ± 4.3 kg; height: 1.73 ± 0.06 m; body fat: 11.6 ± 1.5%) participated. The pre- and post-intervention measures were squat-jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), 5 m and 20 m sprint, change-of-direction ability (4 × 5 m sprint test (S 4 × 5 m)), repeated sprint ability (RSA), and static balance (stork balance test). The training group displayed superior jump (all p 0.49), sprint (p 0.52), change-of-direction ability (p 0.70), and static balance (p 0.49) improvements. Adding bi-weekly PSSCoD improves the athletic performance of young soccer players
Impact of Heat and Drought Stress on Grasspea and Its Wild Relatives
Grasspea (Lathyrus sativus L.) is recognized as a highly drought-tolerant legume. However, excessive consumption of its seeds and green tissues causes neurolathyrism, a condition characterized by an irreversible paralysis of the legs induced by a neurotoxin amino acid called β-N-oxalyl-L-α, β- diaminopropionic acid (β-ODAP). The present study investigated the effects of heat, and combined heat + drought during the reproductive phase on physiological and phenological parameters, yield-related factors, ODAP content, and seed protein of 24 genotypes representing 11 Lathyrus species under controlled conditions. Analysis of variance revealed a highly significant effect (p < 0.001) of stress treatments and genotypes for all the traits. In general, heat stress individually or in combination with drought expedited phenology, reduced relative leaf water content, stimulated proline synthesis, and influenced chlorophyll concentration; the effects were more severe under the combined heat + drought stress. ODAP content in seeds ranged from 0.06 to 0.30% under no-stress conditions. However, under heat stress, there was a significant increase of 33% in ODAP content, and under combined stress (heat + drought), the increase reached 83%. Crude protein content ranged from 15.64 to 28.67% among no stress plants and decreased significantly by 23% under heat stress and by 36% under combined stress. The findings of this study also indicated substantial reductions in growth and grain yield traits under both heat stress and combined heat + drought stress. Six accessions namely IG 66026, IG 65018, IG 65687, IG 118511, IG 64931, and IG65273 were identified as having the most favorable combination of yield, protein content, and seed ODAP levels across all conditions. ODAP content in these six accessions varied from 0.07 to 0.11% under no stress and remained at moderate levels during both heat stress (0.09–0.14%) and combined stress (0.11–0.17%). IG 66026 was identified as the most stable genotype under drought and heat stress conditions with high protein content, and low ODAP content. By identifying those promising accessions, our results have established a basis for forthcoming grasspea breeding initiatives while paving the way for future research exploration into the fundamental mechanisms driving ODAP variation in the presence of both heat and drought stress conditions
Oil prices and stock returns : nonlinear links across sectors
We present evidence of an asymmetric relationship between oil prices and stock returns. The two regime multivariate Markov switching vector autoregressive (MSVAR) model allow us to capture the state shifts in the relationship between regional stock markets and sectors. Results suggest that oil price risk is significantly priced in the sample used. The impact is asymmetric with respect to market phases, and regimes have been associated with world economic, social and political events. Our study also suggests asymmetric responses of sector stock returns to oil price changes and different transmission impacts depending on the sector analyzed. There is a high causality from oil to sectors like Industrials and Oil & Gas. Companies inside the Utilities sector were more able to hedge against oil price increases between 2007 and 2012. Historical crisis events between 1992–1998 and 2003–2007 do not seem to have affected the relationship between oil and sector stock returns, given the higher probability of remaining smoother. For all sectors there seems to be a turn back to stability from 2012 onwards. Finally, investors gain more through portfolio diversification benefits built across, rather than within sectors.info:eu-repo/semantics/publishedVersio
Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes
[EN] Multiple formulations of known biocontrol agent (BCA) Candida sake, containing different coatingforming
polymers and surfactants were tested at different polymer:BCA ratios, in order to improve control
of Botrytis cinerea on grapes. The BCA cell viability on the grape surface was analyzed and reduction in
disease incidence and severity was determined. Coating-forming solids improved the survival and effi-
cacy of C. sake as a BCA against B. cinerea, depending on the polymer type and ratio. The incorporation
of surfactants did not improve survival or disease control, although they promoted a better cell dispersion
on the grape surface. Cell growth of the antagonist during incubation led to the formation of aggregates,
even when surfactants were present. Sodium caseinate and starch were the most suitable polymers to
formulate C. sake preparations to obtain coating-forming systems with this BCA and to increase its survival
and efficacy at the minimum economic cost of the ingredients.
2016 Elsevier Inc. All rights reservedThe authors are grateful to the Spanish Government for the financial support from the national project RTA2012-00067-C02 (Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria, Spain and FEDER founds) and to the Conselleria d'Educacio of the Generalitat Valenciana, (Spain) for A. Marin's PhD grant.Marín-Gozalbo, A.; Cháfer Nácher, MT.; Atarés Huerta, LM.; Chiralt, A.; Torres, R.; Usall, J.; Teixidó, N. (2016). Effect of different coating-forming agents on the efficacy of the biocontrol agent Candida sake CPA-1 for control of Botrytis cinerea on grapes. Biological Control. 96:108-119. https://doi.org/10.1016/j.biocontrol.2016.02.012S1081199
Root Proteomic Analysis of Grapevine Rootstocks Inoculated with Rhizophagus irregularis and Fusarium oxysporum f. sp. herbemontis
Predictors of early post-operative hypocalcemia after parathyroidectomy for secondary hyperparathyroidism
We sought to identify predictors of development of early post-operative hypocalcemia after parathyroidectomy for secondary hyperparathyroidism. The patients were divided into two groups according to their serum calcium (Ca) levels within 24 hours of undergoing para-thyroidectomy: the hypocalcemia group (22 patients) with post-operative serum Ca levels of 2 mmol/L or less, and the normocalcemia group (48 patients), with post-operative serum Ca levels higher than 2 mmol/L. By using multivariate stepwise logistic regression analysis, high pre-operative serum Ca level had the strongest predictive value of development of early hypocalcemia with an adjusted odds ratio (aOR) of 3.01, followed by hypo-albuminemia (aOR = 2.72), younger age (aOR = 2.56), and high pre-operative alkaline phosphatase (ALP) levels (aOR = 2.28). We conclude that among patients with secondary hyperparathyroidism, age, levels of pre-operative serum Ca, ALP and albumin correlate positively with the development of early post-operative hypocalcemia. Patients with one of these factors should be monitored more closely in the early post-parathyroidectomy period
Socioeconomic Status and Tobacco Expenditures among Moroccans: Results of the “Maroc Tabagisme” Survey
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