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Newborn rabbits rely on odour cues to localize and seize maternal nipples. In particular, they orally respond to the mammary
pheromone (MP) emitted in rabbit milk. The activity of the MP was so far mainly investigated in newborns, and a drop in its
releasing effect was shown in 23-day old pups. Here, we evaluated the activity of the MP in a large sample (n=1588) of domestic
rabbit pups tested between birth and weaning. We also assessed whether wild-type pups respond to the MP, and whether the developmental
course of their responsiveness matches the one of domestic pups. During the first postnatal week, the MP revealed to be a
strong releasing stimulus in all pups, regardless of their genetic and environmental background. However, the saliency of
the MP decreased with approaching weaning, and this decrease was clearly steeper in wild-type than in domestic pups. These
results are discussed with regard to the concept of ontogenetic adaptation and the effects of artificial selection. 相似文献
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JC Gaillard Emmanuel A. Maceda Elodie Stasiak Iwan Le Berre Maria Victoria O. Espaldon 《Journal of Coastal Conservation》2009,13(2-3):119-129
The present study investigates into the link between people’s vulnerability in the face of coastal hazards and sustainable livelihoods. It focuses on the town of Borongan in the Philippines and draws on questionnaire-based surveys and focus group discussions. This research shows that local fishermen are often compelled to go out fishing despite pending typhoon or storm surge to sustain the daily needs of their family. Its also demonstrates that the capacity of these people to protect themselves from the threat is constrained by poor and fragile livelihoods. In the event of a crisis, the study argues that people resort to a range of adjustments on their daily life which is rooted in the strength and diversity of their livelihoods. To reduce people’s vulnerability and enhance capacities to face coastal hazards, the study fosters Community-Based Disaster Risk Reduction with special emphasis to sustainable livelihoods. 相似文献
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Characterization and modelling of the heat transfers in a pilot-scale reactor during composting under forced aeration 总被引:1,自引:0,他引:1
The paper focused on the modelling of the heat transfers during composting in a pilot-scale reactor under forced aeration. The model took into account the heat production and the transfers by evaporation, convection between material and gas crossing the material, conduction and surface convection between gas and material in bottom and upper parts of the reactor. The model was adjusted thanks to the measurements practised during fifteen composting experiments in which five organic wastes were, each, composted under three constant aeration rates. Heat production was considered proportional to oxygen consumption rate and the enthalpy per mole oxygen consumed was assumed constant. The convective heat transfer coefficients were determined on basis of the continuous measurements of the temperatures of both the lid and the bottom part of the reactor. The model allowed a satisfying prediction of the temperature of the composting material. In most cases, the mean absolute discard between the experimental and the simulated temperatures was inferior to 2.5°C and the peaks of temperature occurred with less than 8h delay. For the half of the experiments the temperature discard between the simulated peak and the experimental one was inferior to 5°C. On basis of the calculation of a stoichiometric production of water through oxidation of the biodegradable organic matter, the simulation of water going out from material as vapour also allowed a rather satisfying prediction of the mass of water in final mixture. The influence of the aeration rate on every type of heat loss was characterized. Finally, the model was used to evaluate the impacts on material temperature caused by the change of the insulation thickness, the ambient temperature, take the lid away, the increase or the decrease of the mass of waste to compost. 相似文献
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Summary. Lactating rabbit females emit volatile odour cues that trigger specialized motor actions leading to sucking. But the activity
of these cues may change with advancing lactation. Here, we tested this possibility in three experiments. In Exp. 1, we assessed
whether 2-day-old pups respond differently to the odour of milk from females in early (day 2) as compared to late (day 23)
lactation. In Exp. 2, a compound bearing pheromonal properties, the Mammary Pheromone (MP), was dosed in these milks to assess
whether its concentration is correlated with behavioural activity. In Exp. 3, the responsiveness to a constant level of MP
was compared in d2 versus d23-pups. Run on 240 pups, the assays showed that a) the milk activity declines between d2 and d23
of lactation; b) during this same period, the concentration of the MP decreases in milk; c) the MP itself becomes less active
to elicit oral grasping in pre-weaning pups than in newborns. These results indicate that the MP is active during the period
when pups are exclusively dependent on milk. The convergent changes in emission and reception of this pheromone may sequentially
warrant that pups are first attracted to the mammae, and then that they progressively disinvest the mother as they begin to
eat solid food and to be attracted by other conspecifics. 相似文献
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G. Tallec C. Bureau P. Peu J.C. Benoist M. Lemunier A. Budka D. Presse T. Bouchez 《Waste management (New York, N.Y.)》2009,29(7):2078-2084
This study evaluates the impact of nitrate injection on a full scale landfill bioreactor through the monitoring of gaseous releases and particularly N2O emissions. During several weeks, we monitored gas concentrations in the landfill gas collection system as well as surface gas releases with a series of seven static chambers. These devices were directly connected to a gas chromatograph coupled to a flame ionisation detector and an electron capture detector (GC-FID/ECD) placed directly on the field. Measurements were performed before, during and after recirculation of raw leachate and nitrate-enhanced leachate. Raw leachate recirculation did not have a significant effect on the biogas concentrations (CO2, CH4 and N2O) in the gas extraction network. However, nitrate-enhanced leachate recirculation induced a marked increase of the N2O concentrations in the gas collected from the recirculation trench (100-fold increase from 0.2 ppm to 23 ppm). In the common gas collection system however, this N2O increase was no more detectable because of dilution by gas coming from other cells or ambient air intrusion. Surface releases through the temporary cover were characterized by a large spatial and temporal variability. One automated chamber gave limited standard errors over each experimental period for N2O releases: 8.1 ± 0.16 mg m?2 d?1 (n = 384), 4.2 ± 0.14 mg m?2 d?1 (n = 132) and 1.9 ± 0.10 mg m?2 d?1 (n = 49), during, after raw leachate and nitrate-enhanced leachate recirculation, respectively. No clear correlation between N2O gaseous surface releases and recirculation events were evidenced. Estimated N2O fluxes remained in the lower range of what is reported in the literature for landfill covers, even after nitrate injection. 相似文献
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Camille Codaccioni Olivier Picone Véronique Lambert Paul Maurice Léo Pomar Norbert Winer Laurent Guibaud Rose-Anne Lavergne Anne-Hélène Saliou Dorothée Quinio Alexandra Benachi Catherine Noel Yves Ville Fabrice Cuillier Christelle Pomares Nicole Ferret Denis Filisetti Anne-Sophie Weingertner Valérie Vequeau-Goua Estelle Cateau Guillaume Benoist Martine Wallon Marc Dommergues Isabelle Villena Laurent Mandelbrot 《黑龙江环境通报》2020,40(13):1741-1752
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Yang Zeng Amaury de Guardia Mylène Daumoin Jean-Claude Benoist 《Waste management (New York, N.Y.)》2012,32(12):2239-2247
The transformation and transfer of nitrogen during the aerobic treatment of seven wastes were studied in ventilated air-tight 10-L reactors at 35 °C. Studied wastes included distinct types of organic wastes and their digestates. Ammonia emissions varied depending on the kind of waste and treatment conditions. These emissions accounted for 2–43% of the initial nitrogen. Total nitrogen losses, which resulted mainly from ammonia emissions and nitrification–denitrification, accounted for 1–76% of the initial nitrogen. Ammonification was the main process responsible for nitrogen losses. An equation which allows estimating the ammonification flow of each type of waste according to its biodegradable carbon and carbon/nitrogen ratio was proposed. As a consequence of the lower contribution of storage and leachate rates, stripping and nitrification rates of ammonia nitrogen were negatively correlated. This observation suggests the possibility of promotingnitrification in order to reduce ammonia emissions. 相似文献