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211.
Summary. This article surveys early chemosensory mechanisms regulating behaviour in neonatal and juvenile domestic cats (Felis sylvestris catus). It aims to retrieve material from the available literature which may promote a better understanding of the semiochemical
system that supports female-to-kitten exchanges. Studies dealing with the development of olfaction from birth through weaning
are presented in three sections. The first aims at locating developmental periods suitable for applying analytical procedures
combining behaviour and chemistry. The second section offers a survey of observational and experimental work related to the
role of olfaction in the social and feeding behaviour of kittens before weaning. The final section traces the current knowledge
on the odour sources and substrates that may be involved in early mother-kitten transactions. 相似文献
212.
Le Roux G Weiss D Grattan J Givelet N Krachler M Cheburkin A Rausch N Kober B Shotyk W 《Journal of environmental monitoring : JEM》2004,6(5):502-510
A peat core from Lindow bog near Manchester, England, was precisely cut into 2 cm slices to provide a high-resolution reconstruction of atmospheric Pb deposition. Radiocarbon and (210)Pb age dates show that the peat core represents the period ca. 2000 BC to AD 1800. Eleven radiocarbon age dates of bulk peat samples reveal a linear age-depth relationship with an average temporal resolution of 18.5 years per cm, or 37 years per sample. Using the Pb/Ti ratio to calculate the rates of anthropogenic, atmospheric Pb deposition, the profile reveals Pb contamination first appearing in peat samples dating from ca. 900 BC which clearly pre-date Roman mining activities. Using TIMS, MC-ICP-MS, and SF-ICP-MS to measure the isotopic composition of Pb, the (208)Pb/(206)Pb and (206)Pb/(207)Pb data indicate that English ores were the predominant sources during the pre-Roman, Roman, and Medieval Periods. The study shows that detailed studies of peat profiles from ombrotrophic bogs, using appropriate preparatory and analytical methods, can provide new insight into the timing, intensity, and predominant sources of atmospheric Pb contamination, even in samples dating from ancient times. 相似文献
213.
The close genetic linkage between HLA-B and congenital adrenal hyperplasia due to 21-hydroxylase deficiency permits prenatal diagnosis of an affected fetus by HLA typing of amniotic fluid cells in pregnancies at risk. Some families at risk, especially those with an affected girl with ambiguous genitalia, will only plan another pregnancy if a prenatal diagnosis is possible. After HLA typing of the index case, parents and eventually grandparents, the family were informed of the possibility of a prenatal diagnosis. Fibroblast cell lines were initiated from skin biopsies of the index cases and parents and were used as controls in the tests. HLA typing of the fetus was done on amniotic fluid cells grown in vitro using first, a microcytotoxicity test and second quantitative microabsorption test. Ten prenatal diagnoses are reported. In two cases the HLA genotype indicated an affected fetus, examination of the aborted fetuses was in agreement with the diagnosis. In one case an affected male fetus was diagnosed, the pregnancy is in progress. In seven cases an unaffected infant was predicted (four carriers and three homozygous normal infants). 相似文献
214.
Young Nile crocodiles Crocodylus niloticus start to produce calls inside the egg and carry on emitting sounds after hatching. These vocalizations elicit maternal care
and influence the behaviour of other juveniles. In order to investigate the acoustic structure of these calls, focusing on
a possible individual signature, we have performed acoustic analyses on 400 calls from ten young crocodiles during the first
4 days after hatching. Calls have a complex acoustic structure and are strongly frequency modulated. We assessed the differences
between the calls of the individuals. We found a weak individual signature. An individual call-based recognition of young
by the mother is thus unlikely. In other respects, the call acoustic structure changes from the first to the fourth day after
hatching: fundamental frequency progressively decreases. These modifications might provide important information to the mother
about her offspring—age and size—allowing her to customize her protective care to best suit the needs of each individual.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
215.
Chunyan Liu Jirko Holst Zhisheng Yao Nicolas Brüggemann Klaus Butterbach-Bahl Shenghui Han Xingguo Han Xunhua Zheng 《Agriculture, ecosystems & environment》2009,134(1-2):136-142
We investigated nitric oxide (NO) fluxes at a summer and a winter sheepfold in the Baiyinxile livestock farm, near Xilinhot, Inner Mongolia, which are a typical feature of the regional husbandry. Using a manual static opaque chamber/chemiluminescence measuring system, we intermittently observed fluxes in the summer sheepfold between May 28th and September 26th 2005 and in both winter and summer sheepfolds between March 8th and October 18th 2006. During these periods, mean NO emissions (±S.E., in terms of mass of nitrogen) were 124.0 ± 28.7, 134.6 ± 23.3 (summer sheepfold) and 214.4 ± 79.6 μg NO–N m−2 h−1 (winter sheepfold), respectively, and thus, three magnitudes higher than observed steppe NO emissions in the same region. The NO fluxes were not significantly different between the 2 years, but in summer they were much higher than in spring (p < 0.05). Temperature and moisture of the faeces layer significantly regulated the NO fluxes (p < 0.01). The direct NO emission factor (EF) for faeces and urine excreted in the sheepfolds was 0.7 g NO–Nemitted kg−1 Nexcreted, which was almost 37 times lower than a recently reported N2O EF. We estimated the total NO emission from the sheepfolds of the Baiyinxile livestock farm to be 1.82 ± 0.43 tons NO–N year−1, which accounts to approximately 12.3% of the total NO emission from this steppe region. With the rapid increase of livestock numbers, sheepfold NO emissions may further increase and contribute to high N deposition in confined areas around sheepfolds. 相似文献
216.
Estelle J. Villanneau Nicolas P. A. Saby Thomas G. Orton Claudy C. Jolivet Line Boulonne Giovanni Caria Enrique Barriuso Antonio Bispo Olivier Briand Dominique Arrouays 《Environmental Chemistry Letters》2013,11(1):99-104
Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants. Soils are a reservoir of PAHs because some soil constituents favour PAH accumulation. Therefore, soil is a key indicator of the degree of contamination. So far, studies mapping soil PAH levels over large territories are very rare. Here, we report the first nation-wide maps of soil PAHs in France. Results were obtained within the French National Soil Monitoring Network, which is the first European network monitoring systematically soil PAHs. We used advanced geostatistics to map PAH distribution over the whole French territory. Our results show clear trends of PAH levels at the nation scale. For instance, the highest PAH levels are found in Northern and Eastern France. This high contamination is explained by the intense industrial activity of these regions during the last century. High levels of PAH are also found near some coastlines. This observation could be explained by long-range atmospheric transportation. In addition, we found that light PAHs are rarely found in French topsoils. 相似文献
217.
Soil microbial diversity and C turnover modified by tillage and cropping in Laos tropical grassland 总被引:3,自引:0,他引:3
Pascal Lienhard Sébastien Terrat Olivier Mathieu Jean Levêque Nicolas Chemidlin Prévost-Bouré Virginie Nowak Tiffanie Régnier Céline Faivre Sengphanh Sayphoummie Khamkéo Panyasiri Florent Tivet Lionel Ranjard Pierre-Alain Maron 《Environmental Chemistry Letters》2013,11(4):391-398
Agricultural practices should modify the diversity of soil microbes. However, the precise relationships between soil properties and microbial diversity are poorly known. Here, we study the effect of agricultural management on soil microbial diversity and C turnover in tropical grassland of north-eastern Laos. Three years after native grassland conversion into agricultural land, we compared soils from five land use management systems: one till versus two no-till rotational cropping systems, one no-till improved pasture and the natural grassland. Soils were incubated in microcosms during 64 days at optimum temperature and humidity. Bacterial and fungal diversity were evaluated by metagenomic 454-pyrosequencing of 16S and 18SrRNA genes, respectively. Changes in soil respiration patterns were evaluated by monitoring 12C- and 13C-CO2 release after soil amendment with 13C-labelled wheat residues. Results show that residue mineralization increased with bacterial richness and diversity in the tilled treatment 7 days after soil amendment. Native soil organic C mineralization and priming effect increased with fungal richness and diversity in improved pasture and natural grassland. No-till cropping systems represented intermediate situations between tillage and pasture systems. Our findings evidence the potential of controlling soil microbial diversity by agricultural practices to improve soil biological properties. We suggest the promotion of no-till systems as a fair compromise between the need for agriculture intensification and soil ecological processes preservation. 相似文献
218.
219.
220.
Sicard P Dalstein-Richier L Vas N 《Environmental pollution (Barking, Essex : 1987)》2011,159(2):351-362
In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000-2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor’s emissions from Europe have been reduced over the last 20 years. Decreases in annual averages, median, 25th and 98th percentiles and maxima values were found. The seasonal trend analysis for the high-lying stations showed a decreasing trend for the warm season, when main ozone production is the photochemistry, and an increase for the cold period, caused by a reduced ozone titration. Statistics on Arolla Pine reveal strong correlations between mottling intensity and the high ozone concentrations. Finally, decreases for the ozone concentrations, and associated statistics, AOT40 values and for the mottling intensity on conifers needles were observed. 相似文献