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  1. The common hamster Cricetus cricetus was long considered to be a pest species for crops, but its populations are now dramatically declining. The conservation of this species can only be achieved via an up‐to‐date knowledge of its ecology. However, its diet composition has never been exhaustively reviewed and the last peer‐reviewed publication on its feeding ecology in farmlands dates back to 1974.
  2. This review of the literature aims to establish a list of plant and animal taxa consumed by common hamsters, providing knowledge to be applied to the conservation of hamsters and to identify the main avenues of future research.
  3. Hamsters consume four main categories of food: crops, weeds, trees/shrubs and animals, including mammals, birds, herptiles and invertebrates. Vegetable foods are more diverse (114 taxa) than animal foods (11 taxa). Hamsters mainly consume animals and green parts of plants (flowers and leaves) in spring and summer, and store energy‐rich and non‐perishable foods for winter.
  4. Weeds are the most diverse food category (61 taxa), followed by crops (31 taxa). However, diet shifts from crop products towards tree products in urban habitats, probably in response to a marked difference in availability.
  5. We conclude that hamsters have an opportunist diet that shows a high degree of plasticity, and that weeds make up an important part of their food supply. However, the studies published to date have considered diet composition without taking food availability into account, and therefore lack information on whether the hamsters select the foods consumed or simply consume them because other foods are not readily available. Research on food availability and selection is therefore needed. Moreover, we argue that there is a need for recent data on the feeding ecology of the hamster in relation to fitness. This would provide a crucial tool for the implementation of adapted conservation measures for this declining species of rodent.
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Insect vector-borne diseases remain one of the principal causes of human mortality. In addition to conventional measures of insect control, repellents continue to be the mainstay for personal protection. Because of the increasing pyrethroid-resistant mosquito populations, alternative strategies to reconstitute pyrethroid repellency and knock-down effects have been proposed by mixing the repellent DEET (N,N-Diethyl-3-methylbenzamide) with non-pyrethroid insecticide to better control resistant insect vector-borne diseases. By using electrophysiological, biochemichal, in vivo toxicological techniques together with calcium imaging, binding studies and in silico docking, we have shown that DEET, at low concentrations, interacts with high affinity with insect M1/M3 mAChR allosteric site potentiating agonist effects on mAChRs coupled to phospholipase C second messenger pathway. This increases the anticholinesterase activity of the carbamate propoxur through calcium-dependent regulation of acetylcholinesterase. At high concentrations, DEET interacts with low affinity on distinct M1/M3 mAChR site, counteracting the potentiation. Similar dose-dependent dual effects of DEET have also been observed at synaptic mAChR level. Additionally, binding and in silico docking studies performed on human M1 and M3 mAChR subtypes indicate that DEET only displays a low affinity antagonist profile on these M1/M3 mAChRs. These results reveal a selective high affinity positive allosteric site for DEET in insect mAChRs. Finally, bioassays conducted on Aedes aegypti confirm the synergistic interaction between DEET and propoxur observed in vitro, resulting in a higher mortality of mosquitoes. Our findings reveal an unusual allosterically potentiating action of the repellent DEET, which involves a selective site in insect. These results open exciting research areas in public health particularly in the control of the pyrethroid-resistant insect-vector borne diseases. Mixing low doses of DEET and a non-pyrethroid insecticide will lead to improvement in the efficiency treatments thus reducing both the concentration of active ingredients and side effects for non-target organisms. The discovery of this insect specific site may pave the way for the development of new strategies essential in the management of chemical use against resistant mosquitoes.  相似文献   
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Various 3-amino-, 3-aryloxy- and alkoxy-6-arylpyridazines have been synthesized by an electrochemical reductive cross-coupling between 3-amino-, 3-aryloxy- or 3-alkoxy-6-chloropyridazines and aryl or heteroaryl halides. In vitro antiproliferative activity of these products was evaluated against a representative panel of cancer cell lines (HuH7, CaCo-2, MDA-MB-231, HCT116, PC3, NCI-H727, HaCaT) and oncogenicity prevention of the more efficient derivatives was highlighted on human breast cancer cell line MDA-MB 468-Luc prior establishing their interaction with p44/42 and Akt-dependent signaling pathways.  相似文献   
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We tested whether a simple overweight prevention program promoting water consumption in elementary schools is equally effective in children with an immigrational background (MIG) and in those without (non‐MIG). Thus, a secondary analysis of a controlled cluster trial, lasting one school year, was conducted. Thirty‐two elementary schools located in low socioeconomic districts in two German cities were included. Of the 2,950 school children analyzed, 1,306 were MIG children. Water fountains were installed in the schools of the intervention group (IG) and teachers held lessons to promote water consumption. Control schools (control group (CG)) did not receive any intervention. Before and after intervention, body weight and height was measured. Overweight was defined by age‐ and sex‐specific BMI cutoffs that are linked to an adult BMI of 25 kg/m2. Beverage consumption was assessed in questionnaires. Modification of intervention effects by immigrational background was tested by interaction terms. The immigrational background modified the intervention effect on prevalence and remission of overweight (interaction term: P = 0.03 and P = 0.02), but not on the incidence of overweight (P = 0.06). After intervention, the risk of being overweight was reduced in the IG compared to the CG among non‐MIG (odds ratio = 0.51, 95% confidence interval (CI): 0.31–0.83), but not among MIG children (odds ratio = 1.02, 95% CI: 0.63–1.65). After intervention, water consumption significantly increased in the IG equally among both, non‐MIG and MIG, by ~1 glass/day. A simple school‐based intervention promoting water consumption prevented overweight in non‐MIG children, but failed in MIG children. Different beverage consumption, among other lifestyle factors, may account for this effect but scientific discussion remains open.  相似文献   
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When leaves act like flowers: how dwarf palms attract their pollinators   总被引:2,自引:0,他引:2  
In pollination mutualisms, floral odours are signals advertising the presence and location of rewards. However, in the case of the dwarf palm (Chamaerops humilis) and its species‐specific pollinating weevil (Derelomus chamaeropsis), rewards and advertisements are spatially separated. Flowers provide their specific pollinators with food and sites for both egg laying and larval development, but do not advertise them with floral odours or visually conspicuous petals. Insect behavioural bioassays revealed that pollinators are attracted by scents emitted by the leaves, which provide no rewards. These scents are released by large structures located at the sinuses of the palmate leaf. Such scent‐releasing structures have not been previously reported on palm leaves, and we suggest that they may represent an ‘exaptation’ (pre‐existing trait that acquired new functions). We also propose that such functional crossovers between vegetative and reproductive domains may be more frequent in plants than is currently documented.  相似文献   
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Background

The deleterious health effects of sedentary behaviors, independent of physical activity, are increasingly being recognized. However, associations with cognitive performance are not known.

Purpose

To estimate the associations between different sedentary behaviors and cognitive performance in healthy older adults.

Methods

Computer use, time spent watching television (TV), time spent reading and habitual physical activity levels were self-reported twice (in 2001 and 2007) by participants in the SUpplémentation en Vitamines et MinérauX (SU.VI.MAX and SU.VI.MAX2) study. Cognitive performance was assessed at follow-up (in 2007–2009) via a battery of 6 neuropsychological tests used to derive verbal memory and executive functioning scores. Analyses (ANCOVA) were performed among 1425 men and 1154 women aged 65.6±4.5 at the time of the neuropsychological evaluation. We estimated mean differences with 95% confidence intervals (95%CI) in cognitive performance across categories of each type of sedentary behavior.

Results

In multivariable cross-sectional models, compared to non-users, participants using the computer for >1 h/day displayed better verbal memory (mean difference = 1.86; 95%CI: 0.95, 2.77) and executive functioning (mean difference = 2.15; 95%CI: 1.22, 3.08). A negative association was also observed between TV viewing and executive functioning. Additionally, participants who increased their computer use by more than 30 min between 2001 and 2007 showed better performance on both verbal memory (mean difference = 1.41; 95%CI: 0.55, 2.27) and executive functioning (mean difference = 1.41; 95%CI: 0.53, 2.28) compared to those who decreased their computer use during that period.

Conclusion

Specific sedentary behaviors are differentially associated with cognitive performance. In contrast to TV viewing, regular computer use may help maintain cognitive function during the aging process.

Clinical Trial Registration

clinicaltrial.gov (number NCT00272428).  相似文献   
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