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Direct and indirect effects of metal stress on physiology and life history variation in field populations of a lycosid spider 总被引:1,自引:0,他引:1
Eraly D Hendrickx F Backeljau T Bervoets L Lens L 《Ecotoxicology and environmental safety》2011,74(6):1489-1497
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- Under stress, life history theory predicts reduced growth rates and adult sizes, reduced reproductive allocation, production of larger offspring and postponed reproduction. Both direct and indirect effects of metals can explain these trends, mainly linked to energetic constraints. Metallothionein-like proteins (MTLP’s) are believed to be an important defense mechanism against the adverse effects of metals and other stressors.
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- We tested these predictions comparing six field populations of the wolf spider Pardosa saltans, three of which were on sites that are historically polluted with heavy metals.
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- As expected for life histories evolving under energetic constraints, adult size and condition correlated negatively and egg mass positively with Cd concentrations for a subset of four populations. In the population that showed the highest cadmium and zinc body burdens, reproductive output and allocation were lowest and reproduction was postponed.
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- Contrary to our expectation, for all six study populations MTLP concentrations did not increase in exposed populations, indicating that this defense mechanism cannot explain the observed variation in life histories.
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- We conclude that indirect and synergistic effects of metal pollution may be more important than physiological defense mechanisms in shaping life history traits in field populations.
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Wenyi ZhangElizabeth Joseph Charles HitchcockRobert A. DiSilvestro 《Nutrition Research》2011,31(2):165-168
Two concepts are often currently applied to selenium in adult men in the United States:
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- Intake is generally enough to maximize blood glutathione peroxidase activities.
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- In such men, selenium supplementation does not reduce risk of prostate cancer.
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Daniel Rigaud Claude Fischler Hélène Pennacchio Omer Van den Bergh Matty Chiva† 《Cahiers de Nutrition et de Diététique》2006,41(6):353-363
Purpose: it was to know the cognitive and emotional thoughts concerning foods and eating in the general and student population of the region of Dijon.Methods: a questionnaire concerning the cognitive and emotional thoughts was beforehand established, validated and handed or sent to 10 000 students and persons of the population of Dijon drawn lots and paired according to district and family. The analysis concerned 3 732 persons, i.e. the 882 students and the 2 850 people of both genders from the general population who restored a more than 95% completed and coherent questionnaire.Results: in this population, negative thoughts and fear in front of the food were noted in a not exceptional way:
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- to eat disgusts me: 1.6%;
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- to eat frightens me: 3.3%;
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- the glance of the other one when I eat frightens me: 13%;
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- this food which we propose me make me bad, sink, sad or tightened in 9 at 18% of the cases.
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- binge eating: 8%;
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- bulimia nervosa: 4.3%;
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- anorexia nervosa: 2.2%;
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- low weight (IMC<19 kg/(m)2) and frightens in front of glance of the other one: 13%.
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Caroline Carriere Élodie Saubusse Colette Delmas Martine Ruello 《Cahiers de Nutrition et de Diététique》2008,43(3):147-151
Within the framework of the French National Programme on Nutrition and Health, a survey was conducted in middle and high schools of the French Aquitaine region with the aim of describing the food supply within middle and high schools in 2004-2005, before and after the application of regulation of snack machins in September 2005 of the recent French law of public health.The results show that:
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- 20 % of schools offered free snacks, specially bread (67 %) and fruit (39,3 %).
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- 63 % of the answering schools had food or drink sales, concerning pastries (74,6 %), chocolate bars (30 %) and soft drinks (25,4 %).
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- In 2004-2005, 44 % of the high schools had snack machins. In Septembre 2005, each school (99 %) had removed on snack machines.
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Jean-Michel Lecerf 《Cahiers de Nutrition et de Diététique》2008,43(3):138-146
From a quantitative point of view the role of dietary fat in weight gain apparently seems clear, but its accountability in obesity pathogenesis, for individuals or population, is not definitively established.This concern may be divided in four sections:
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- On a physiopathological point of view, experimental data show that fats are able to increase energy density and food intake and to increase lipogenesis.
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- On an epidemiological point of view the data are more conflicting. An higher fat intake was associated to the obesity epidemic, its decrease did not stopped it, and that suggest the role of others lifestyle patterns including physical activity.
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- On a clinical point of view the studies are far from a consensus, but it is true that they focuse on the role of familial, educative and genetic factors. But really a fat excess can sensitive the effect of inactivity. Total energy intakes seem a main issue.
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- The fat reduction is not sufficient to induce a weight loss or to prevent a weight gain. We must act on each component of energy balance. In insulin-resistant subjects the fat reduction without weight-loss does not seem favourable on cardiovascular risk.
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People vaccinated against influenza develop hemagglutination inhibition (HAI) antibodies (Ab) that bind to the virus and neutralize it. Ab titer levels are variable depending on factors insufficiently studied, and tend to decrease over time.In the present study, we analyzed antibodies responses before and after influenza vaccination in nurses working in a hospital, with the aim of:
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- identifying seroconversion rates to trivalent influenza vaccine one month after immunization;
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- evaluating if, six months after vaccination, influenza HAI Ab titer fall comparing to one-month post vaccination HAI Ab titer;
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- studying the association between the lack of HAI Ab response (seroconversion) assessed one month after immunization and:
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- past influenza vaccinations,
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- baseline (before vaccination) HAI Ab titer,
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- baseline (before vaccination) HAI Ab titer ≥ 40 (considered as a protection titer).
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- 1. A survey of about 1700 children from 24 schools scattered over the Kano Plain showed a Schistosoma haematobium infection rate of less than 4%. Surveys of 2 adjacent areas showed S. haematobium to be nearly 10 times as prevalent as on the plain. 相似文献
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- 1. A complement fixation technique for 60°C.-inactivated sera, suited to the diagnosis of amoebic disease, is described. 相似文献
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Study of evaluate the effects of multiphasic screening within general practice in Britain: design and method 总被引:1,自引:0,他引:1
H Trevelyan 《Preventive medicine》1973,2(2):278-294
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C Bull S A Cockett 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1972,66(6):916-920
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- 1. Suspensions of microfilariae were prepared in haematocrit tubes with “bait” solutions apposed to one end of the column to discover whether any specific tactic influences were operating. 相似文献
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