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41.
Mixed biodiversity benefits of agri-environment schemes in five European countries 总被引:11,自引:1,他引:10
Kleijn D Baquero RA Clough Y Díaz M De Esteban J Fernández F Gabriel D Herzog F Holzschuh A Jöhl R Knop E Kruess A Marshall EJ Steffan-Dewenter I Tscharntke T Verhulst J West TM Yela JL 《Ecology letters》2006,9(3):243-254
Agri-environment schemes are an increasingly important tool for the maintenance and restoration of farmland biodiversity in Europe but their ecological effects are poorly known. Scheme design is partly based on non-ecological considerations and poses important restrictions on evaluation studies. We describe a robust approach to evaluate agri-environment schemes and use it to evaluate the biodiversity effects of agri-environment schemes in five European countries. We compared species density of vascular plants, birds, bees, grasshoppers and crickets, and spiders on 202 paired fields, one with an agri-environment scheme, the other conventionally managed. In all countries, agri-environment schemes had marginal to moderately positive effects on biodiversity. However, uncommon species benefited in only two of five countries and species listed in Red Data Books rarely benefited from agri-environment schemes. Scheme objectives may need to differentiate between biodiversity of common species that can be enhanced with relatively simple modifications in farming practices and diversity or abundance of endangered species which require more elaborate conservation measures. 相似文献
42.
Rutten Anne L.; Oosterbeek Kees; Ens Bruno J.; Verhulst Simon 《Behavioral ecology》2006,17(2):297-302
Intake rate maximization alone is not always sufficient in explainingprey size selection in predators. For example, bivalve-feedingoystercatchers regularly select smaller prey than expected ifthey aimed to maximize their intake rate. It has been proposedthat to these birds large prey are "risky," in the sense thatbirds may damage their bills when feeding on large bivalves.Large bivalves yield more energy, but according to this hypothesisthis is achieved at the expense of energy yield in the longterm when (1) the risk of bill damage increases with prey sizeand (2) foraging with a damaged bill is less effective. In accordancewith this hypothesis, we show that captive oystercatchers feedingon large cockles experienced a high probability of bill tipdamage, while bill damage was absent when cockles were small.Moreover, among free-living oystercatchers the prevalence ofbill damage was correlated with mean cockle size near the capturesite, and the data on captive birds fit in this pattern. Foodintake of captive oystercatchers feeding exclusively on cockleswas reduced by 23% after bill damage, and free-living birdswith damaged bills had 14 g lower mass. Because lower body masswas associated with higher mortality probability, these resultsindicate long-term costs associated with feeding on large cockles.We conclude that the risk of bill damage can potentially explainwhy oystercatchers avoid large bivalves and that oystercatchersmay maximize long-term intake rate by selecting prey sizes thatare "suboptimal" from a short-term rate-maximizing point ofview. 相似文献
43.
44.
Quantitative genetic analysis of internalising and externalising problems in a large sample of 3-year-old twins. 总被引:1,自引:0,他引:1
For a quantitative genetic study of pre-school problem behaviours, we have collected data with the Child Behavior Checklist for 2 and 3-year-old children (CBCL 2/3). Questionnaires were completed by mothers of 3620 twin pairs: 633 monozygotic males, 581 dizygotic males, 695 monozygotic females, 519 dizygotic females and 1192 dizygotic opposite sex twin pairs. The genetic and environmental influences on the Externalising and Internalising Problem scales were estimated, simultaneously with sex differences and sibling interaction effects. Genetic factors explained most of the observed variance for both Externalising and Internalising Problems. Cooperative sibling interactions were found for Externalising Problems, indicating that twins reinforce each other's behaviour. Sex differences in genetic architecture were found for Externalising Problems. Genetic factors explained 75% of the variance in girls and 50% in boys. Shared environmental influences were only of importance in boys. For both problem scales, non-shared environmental factors accounted for 25 to 32% of the variance. The observed variances of Internalising Problems could be adequately explained by genetic and nonshared environmental factors, with genetic factors accounting for 68% of the variance. 相似文献
45.
Mowlavi A Andrews K Lille S Verhulst S Zook EG Milner S 《Plastic and reconstructive surgery》2000,106(2):327-334
Despite extensive clinical experience in treating cubital tunnel syndrome, optimal surgical management remains controversial. A meta-analysis of 30 studies with accurate preoperative and postoperative staging was undertaken. Patients were staged preoperatively into minimum, moderate, and severe groups on the basis of clinical presentation. Treatment modalities included nonoperative management, surgical decompression, medial epicondylectomy, anterior subcutaneous transposition, and anterior submuscular transposition. Statistical analysis using a standard SAS database with analysis of variance and chi-square tests was used to assess the efficacy of each therapeutic modality. For minimum-staged patients, all modalities produced similar degrees of satisfaction. However, total relief occurred most after medial epicondylectomy and least after anterior subcutaneous transposition. Patients treated nonoperatively had the highest rate of recurrence. For moderate-staged patients, submuscular transposition was most efficacious, whereas patients with nonoperative management fared the worst. Finally, for severe-staged patients, current therapeutic modalities were not consistently effective, with medial epicondylectomy producing the poorest operative result. This article reveals statistically significant differences in outcomes among therapeutic modalities, which may assist in treatment planning; it introduces standardized methods to aid in determining, analyzing, and communicating treatment outcomes. 相似文献
46.
Michael?B?Kupper Michael?Huhn Holger?Spiegel Julian?KC?Ma Stefan?Barth Rainer?Fischer Ricarda?FinnernEmail author 《BMC biotechnology》2005,5(1):4
Background
Common oral diseases and dental caries can be prevented effectively by passive immunization. In humans, passive immunotherapy may require the use of humanized or human antibodies to prevent adverse immune responses against murine epitopes. Therefore we generated human single chain and diabody antibody derivatives based on the binding characteristics of the murine monoclonal antibody Guy's 13. The murine form of this antibody has been used successfully to prevent Streptococcus mutans colonization and the development of dental caries in non-human primates, and to prevent bacterial colonization in human clinical trials. 相似文献47.
The variation in time and energy allocation of female great tits, Parus major, was studied in five different European populations across a latitudinal gradient. Daily energy expenditure (DEE) was measured
in females tending 12-day-old broods. The number of daylight hours used by the parents to collect food for the brood increased
with latitude, while DEE and feeding rate per brood tended to level off with latitude. Individual variation in DEE could be
explained by variation in ambient temperature (–), the duration of activity period (+) and area, but not by brood size, female
body mass, brood mass or feeding rate. When the effect of ambient temperature and the duration of the activity period on the
day of energy expenditure measurements were controlled for, female DEE still tended to level off with latitude. Temperature
and activity alone can thus not explain the observed pattern. The present study suggests that parents at southern latitudes
may be under a time constraint and do not increase energy expenditure because they have no more daylight hours available for
foraging, while birds at northern latitudes may be under an energy constraint because they do not make full use of the long
daylight period available.
Received: 25 May 1999 / Accepted: 08 September 1999 相似文献
48.
Zeyuan Song Tao Wu Jinpeng Sun Haoran Wang Feng Hua Yap San Min Nicolas Rupesh KC Kun Chen Zhen Jin Jun Liu Mingshun Zhang 《Journal of cellular and molecular medicine》2021,25(7):3272-3283
Excessive post-epidural fibrosis is a common cause of recurrent back pain after spinal surgery. Though various treatment methods have been conducted, the safe and effective drug for alleviating post-epidural fibrosis remains largely unknown. Metformin, a medicine used in the treatment of type 2 diabetes, has been noted to relieve fibrosis in various organs. In the present study, we aimed to explore the roles and mechanisms of metformin in scar formation in a mouse model of laminectomy. Post-epidural fibrosis developed in a mouse model of laminectomy by spinous process and the T12-L2 vertebral plate with a rongeur. With the administration of metformin, post-epidural fibrosis was reduced, accompanied with decreased collagen and fibronectin in the scar tissues. Mechanistically, metformin decreased fibronectin and collagen deposition in fibroblast cells, and this effect was dependent on the HMGB1/TLR4 and TGF-β1/Smad3 signalling pathways. In addition, metformin influenced the metabolomics of the fibroblast cells. Taken together, our study suggests that metformin may be a potential option to mitigate epidural fibrosis after laminectomy. 相似文献
49.
Karin Veldman Ute Bültmann Roy E. Stewart Johan Ormel Frank C. Verhulst Sijmen A. Reijneveld 《PloS one》2014,9(7)
BackgroundThis study examines if mental health problems at age 11 and changes in mental health problems between age 11 and 16 predict educational attainment of adolescents at age 19, overall and stratified by gender.MethodsData from 1711 adolescents (76.8% from initial cohort) of the Tracking Adolescents'' Individual Lives Survey (TRAILS), a Dutch prospective cohort study with 9year follow-up, were used. Mental health problems (externalizing, internalizing and attention problems) were measured by the Youth Self Report and the Child Behavior Checklist at ages 11 and 16. Difference scores for mental health problems between age 11 and 16 were calculated. Educational attainment was assessed at age 19.ResultsExternalizing, internalizing and attention problems at age 11 were significantly associated with low educational attainment at age 19 (crude model). When adjusted for demographic variables and the other mental health problems, only the association for attention problems remained significant (odds ratio (OR), 95% confidence interval: 3.19, 2.11–4.83). Increasing externalizing problems between age 11 and 16 also predicted low educational attainment at age 19 (OR 3.12, 1.83–5.32). Among girls, increasing internalizing problems between age 11 and 16 predicted low educational attainment (OR 2.21, 1.25–3.94). For boys, no significant association was found for increasing internalizing problems and low educational attainment. For increasing attention problems between age 11 and 16 no significant association with low educational attainment was found.ConclusionsExternalizing, internalizing and attention problems at age 11 and an increase of these problems during adolescence predicted low educational attainment at age 19. Early treatment of these mental health problems may improve educational attainment, and reduce socioeconomic health differences in adulthood. 相似文献
50.
Dietary restriction (DR) extends lifespan in multiple species from various taxa. This effect can arise via two distinct but not mutually exclusive ways: a change in aging rate and/or vulnerability to the aging process (i.e. initial mortality rate). When DR affects vulnerability, this lowers mortality instantly, whereas a change in aging rate will gradually lower mortality risk over time. Unraveling how DR extends lifespan is of interest because it may guide toward understanding the mechanism(s) mediating lifespan extension and also has practical implications for the application of DR. We reanalyzed published survival data from 82 pairs of survival curves from DR experiments in rats and mice by fitting Gompertz and also Gompertz–Makeham models. The addition of the Makeham parameter has been reported to improve the estimation of Gompertz parameters. Both models separate initial mortality rate (vulnerability) from an age‐dependent increase in mortality (aging rate). We subjected the obtained Gompertz parameters to a meta‐analysis. We find that DR reduced aging rate without affecting vulnerability. The latter contrasts with the conclusion of a recent analysis of a largely overlapping data set, and we show how the earlier finding is due to a statistical artifact. Our analysis indicates that the biology underlying the life‐extending effect of DR in rodents likely involves attenuated accumulation of damage, which contrasts with the acute effect of DR on mortality reported for Drosophila. Moreover, our findings show that the often‐reported correlation between aging rate and vulnerability does not constrain changing aging rate without affecting vulnerability simultaneously. 相似文献