Behavioural research on domestic pigs has included parent–offspring conflict, sibling competition, and the use of signals
which influence resource allocation. In this paper, we review key sow–piglet behavioural studies and discuss their relevance
to resource allocation theory. Sibling competition begins in the uterus and continues after birth, as piglets compete directly
for access to the sow’s teats. This competition is made more severe by a unique dentition, which newborn piglets use to lacerate
the faces of siblings during teat disputes. Competition often leads to the death of some littermates, especially those of
low birth weight. Piglets also compete indirectly for milk, apparently by stimulating milk production at the teats that they
habitually use at the expense of milk production by other teats. The complex nursing behavior of the sow appears designed
to prevent the more vigorous piglets from monopolizing the milk. Sows give vocal signals which both attract piglets to suckle
and synchronize their behavior during nursing episodes. Piglets give loud vocal signals when separated from the sow; calls
which vary in intensity and appear to be honest signals of need. Udder massage by piglets may also serve as an honest signal
of need. Parent–offspring conflict has been demonstrated experimentally in pigs. Specifically, when given the opportunity
to control contact with their piglets, sows nurse less frequently, provide less milk, and lose less weight during lactation
than sows that cannot control their level of contact. Because of this interesting natural history and because they are so
amenable to experimentation, domestic pigs provide a rich system for testing ideas drawn from resource allocation theory.
This contribution is part of the special issue “Sibling competition and cooperation in mammals” (guest editors: Robyn Hudson
and Fritz Trillmich). 相似文献
Environmental Science and Pollution Research - European Association of Spa Rehabilitation (ESPA) recommends spa rehabilitation for patients with post-COVID-19 syndrome. We tested the hypothesis... 相似文献
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Environmental Science and Pollution Research - The European Interreg Italy–France 2014–2020 Maritime Project SPlasH! (Stop to Plastics in H2O!) focused on the study of microplastics... 相似文献
Modern agriculture is dependent on phosphate rock (PR), which is a nonrenewable resource. Improvement of phosphorus (P) availability for crops in agricultural soils represents a key strategy to slow down the depletion of PR. The aim of this study was to identify potential P biofertilisers among saprotrophic fungal species. We tested 30 fungal strains belonging to 28 taxa (4 Zygomycota and 24 Ascomycota) and with different life strategies. The study showed that many saprotrophic fungi have the ability to mobilise P from insoluble forms according to a variety of mechanisms. Our results expand the pool of P solubilising fungal species, also suggesting a new solubilisation index and shedding light on parameters that could be basic in the selection of efficient soil P-biofertilisers fungi. Rhizopus stolonifer var. stolonifer, Aspergillus niger and Alternaria alternata were found to be the best performing strains in terms of amounts of TCP solubilisation. 相似文献
The objective of this study was to assess the contamination level of potentially harmful elements (PHEs) in industrial soils and how this relates to environmental magnetism. Moreover, emphasis was given to the determination of the potential mobile fractions of typically “technogenic” metals. Therefore, magnetic and geochemical parameters were determined in topsoils (0–20 cm) collected around a chemical industry in Sindos Industrial Area, Thessaloniki, Greece. Soil samples were presented significantly enriched in “technogenic” metals such Cd, Pb, and Zn, while cases of severe soil contamination were observed in sampling sites north-west of the industrial unit. Contents of Cd, Cr, Cu, Ni, Pb, Mo, Sb, Sn, and Zn in soils and pollution load index (PLI) were highly correlated with mass specific magnetic susceptibility (χlf). Similarly, enrichment factor (EF) and geoaccumulation index (Igeo) for “technogenic” Pb and Zn exhibited high positive correlation factors with χlf. Principal component analysis (PCA) classified PHEs along with the magnetic variable (χlf) into a common group indicating anthropogenic influence. The water extractable concentrations were substantially low, while the descending order of UBM (Unified BARGE Method) extractable concentrations in the gastric phase was Zn > Pb > As > Cd, yet Cd showed the highest bioaccessibility (almost 95%).
There is tenure insecurity around land ownerships and land rights in most developing countries. There are also many land-use planning projects being implemented in these countries. Often, land-use planning exists in these countries but is not formally linked with tenure security. This study argues that combining them by conducting land-use planning in a way that promotes tenure security presents a new approach. A central premise for the rationale of this intervention is that processes of land-use planning may inadvertently increase tenure security. By way of methodology, it evaluates land-use planning case studies from Africa, Asia and South America. It uses the three case study examples to build a case for making tenure security one of the major planned outcomes of a land-use planning process and provides a detailed framework for operationalising the concept. Its main contribution to the literature is that it introduces the concept of tenure responsive land-use planning. 相似文献
Anaerobic digestion of organic waste yields energy rich biogas and retains nutrients (N, P, K, S, etc.) in a stabilised residue. For the residue to be used as a soil fertiliser, it must be free from pollutants and harmful microorganisms. Fungal survival during sanitation and anaerobic treatment of source-separated organic household waste and during aerobic storage of the residue obtained was investigated. Decimal reduction times were determined for inoculated fungi (Aspergillus flavus and Aspergillus fumigatus, Penicillium roqueforti, Rhizomucor pusillus, Thermoascus crustaceus and Thermomyces lanuginosus). Several different fungal species were found after waste sanitation treatment (70 degrees C, 1 h), with Aspergillus species dominating in non-inoculated waste. Anaerobic waste degradation decreased the diversity of fungal species for processes run at both 37 and 55 degrees C, but not total fungal colony forming units. Fungi surviving the mesophilic anaerobic digestion were mainly thermotolerant Talaromyces and Paecilomyces species. T. crustaceus and T. lanuginosus were the only inoculated fungi to survive the thermophilic anaerobic degradation process. Aerobic storage of both types of anaerobic residues for one month significantly decreased fungal counts. 相似文献
The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3–C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO2 levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor. 相似文献
Total suspended particulate (TSP), PM(2.5) and BTEX were collected in nine offices in the province of Antwerp, Belgium. Both indoor and outdoor aerosol samples were analysed for their weight, elemental composition, and water-soluble fraction. Indoor TSP and PM(2.5) concentrations ranged from 7-31 microg m(-3) and 5-28 microg m(-3), with an average of 18 and 11 microg m(-3), respectively. Of all the elements analysed in indoor TSP, more than 95% was represented by Al, Si, K, Ca, Fe, Cl and S, accounting for 12% of the TSP by mass. The other elements showed significant enrichment relative to the earth's crust. The water-soluble ionic fraction accounted for almost 30% of the sampled indoor TSP by weight, and was enriched by anthropogenic activities. It was shown that the indoor PM levels varied among the offices, depending on the ventilation pattern, location, and occupation density of the office. Indoor BTEX levels ranged together from 5-47 microg m(-3) and were considerably higher than the corresponding outdoor levels. It was observed that some recently constructed and renovated buildings were clearly burdened with elevated levels for toluene, ethyl benzene, and xylenes, while outdoor air was found to be the main source for BTEX levels at the 'older' offices. 相似文献