Self-similarity in the distribution and abundance of species     

Harte J  Kinzig A  Green J 《Science (New York, N.Y.)》1999,284(5412):334-336

If the fraction of species in area A that are also found in one-half of that area is independent of A, the distribution of species is self-similar and a number of observed patterns in ecology, including the widely cited species-area relationship connecting species richness to censused area, follow. Self-similarity also leads to a species-abundance distribution, which deviates considerably from the commonly assumed lognormal distribution and predicts considerably more rare species than the latter. Because the abundance distribution is derived under the condition of self-similarity, it may be widely applicable beyond ecology.  相似文献   

Circadian rhythms. Clocks on the brain     

Green CB  Menaker M 《Science (New York, N.Y.)》2003,301(5631):319-320

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Light adaptation in the rat retina: evidence for two receptor mechanisms   总被引：5，自引：0，他引：5  

D G Green 《Science (New York, N.Y.)》1971,174(9):598-600

Light adapting the rat retina with transient white flashes too dim to bleach a substantial amount of visual pigment produces a change in electroretinogram spectral sensitivity and an increase in flicker fusion frequency. Increment threshold curves obtained with a long wavelength adapting stimulus and a short wavelength test stimulus show rod saturation.  相似文献   

Small- and large-scale network structure of live fish movements in Scotland     

Darren Michael Green  Alison Gregory  Lorna Ann Munro 《Preventive veterinary medicine》2009,91(2-4):261-269

Networks are increasingly being used as an epidemiological tool for studying the potential for disease transmission through animal movements in farming industries. We analysed the network of live fish movements for commercial salmonids in Scotland in 2003. This network was found to have a mixture of features both aiding and hindering disease transmission, hindered by being fragmented, with comparatively low mean number of connections (2.83), and low correlation between inward and outward connections (0.12), with moderate variance in these numbers (coefficients of dispersion of 0.99 and 3.12 for in and out, respectively); but aided by low levels of clustering (0.060) and some non-random mixing (coefficient of assortativity of 0.16). Estimated inter-site basic reproduction number R₀ did not exceed 2.4 at high transmission rate. The network was strongly organised into communities, resulting in a high modularity index (0.82). Arc (directed connection) removal indicated that effective surveillance of a small number of connections may facilitate a large reduction in the potential for disease spread within the industry. Useful criteria for identification of these important arcs included degree- and betweenness-based measures that could in future prove useful for prioritising surveillance.  相似文献   

Reproductive Performance of Gilts with Similar Age but with Different Growth Rate at the Onset of Puberty Stimulation   总被引：1，自引：0，他引：1  

R Kummer  ML Bernardi  AC Schenkel  WS Amaral Filha  I Wentz  FP Bortolozzo 《Reproduction in domestic animals》2009,44(2):255-259

The aim of this study was to evaluate the reproductive performance of gilts that had a similar age but different weights at the onset of puberty stimulation by boar exposure at 144 days. Gilts were divided into two groups according to their lifetime growth rate from birth to approximately 144 days of age. Mean growth rates at this moment were 577 and 724 g/day for group 1 (G1; n = 58) and group 2 (G2; n = 58), respectively. After selection, gilts were weighed at approximately 155, 165 and 175 days of age, on the insemination day and at slaughter. Gilts were inseminated, on average, at 193 days of age and were slaughtered 32 days after insemination, when the number of corpora lutea and embryos were recorded. Higher growth rate gilts (G2) reached puberty earlier (155.3 vs 164.1 days; p < 0.01). More gilts of G2 group attained puberty by 190 days of age (p = 0.004) than G1 gilts (95%; 55/58 vs 76%; 44/58). The anoestrous rate, until 60 days after the onset of boar exposure was higher (p < 0.01) in G1 (19.0%; 11/58) than in G2 (3.4%; 2/58) group. However, there were no differences in the pregnancy rate (90.7 vs 94.5), ovulation rate (15.9 vs 16.5), total embryos (12.9 vs 11.7), viable embryos (12.0 vs 11.1) and embryo survival (73.7% vs 68.5%), between G1 gilts and G2 gilts, respectively (p > 0.05). High growth rate gilts attain puberty earlier and have a lower anoestrous rate than low growth rate gilts.  相似文献   

Viability of OPS Vitrified Sheep Embryos After Direct Transfer     

RE Green  BFS Santos  CC Sicherle  FC Landim-Alvarenga  SD Bicudo 《Reproduction in domestic animals》2009,44(3):406-410

The aim of this study was to evaluate the viability in the effect of open pulled straw (OPS) vitrification procedure of sheep embryos after direct transference. Embryos were produced in vivo and cryopreserved in slow freezing or OPS vitrification. The survival rates of cryopreserved embryos were compared to non-frozen standard pattern. In a first set of experiments, embryos at morula and blastocyst stages were dived in ethylene glycol (1.5 M) and frozen in an automatic freezer. After being thawed, they were directly or indirectly transferred to ewes recipient. A second group of embryos were drawn into OPS and plunged into liquid nitrogen after being exposed at room temperature for 1 min and 45 s in 10% EG plus 10% dimethyl sulphoxide (DMSO), then again for 30 s in 20% EG + 20% DMSO + 0.5 M sucrose. After being warmed, embryos were also directly transferred using a French mini straw as the catheter for the transplantation process or after in vitro dilution of cryoprotectants (two-step-process). No significant difference was observed among fresh, frozen or vitrified embryos on pregnancy rate (50.0%, 38.6% and 55.8%). However, when we evaluated only the direct transference, the pregnancy rate of OPS vitrified embryos was higher than that of frozen embryos (57.1% vs 34.8%) (p = 0.07). In addition, vitrified morulae had a higher pregnancy rate than the one with frozen embryos (64.0% vs 38.9%) (p = 0.07). Finally, our results indicate that OPS vitrification technique in association with direct transference improves the viability of sheep embryos with potential applications to field conditions.  相似文献   

The inter- and intra-observer reliability of a locomotion scoring scale for sheep     

Kaler J  Wassink GJ  Green LE 《Veterinary journal (London, England : 1997)》2009,180(2):189-194

A seven point locomotion scoring scale, ranging from 0=normal locomotion to 6=unable to stand or move, has been developed. To test the between and within observer reliability of the scale, 65 movie clips of sheep with normal and varying degrees of abnormal locomotion were made. Three observers familiar with sheep locomotion were trained to read the movie clips. Thirty clips were randomly selected and used to test between and within observer agreement. There was high inter-(intra-class correlation coefficient [ICC]=0.93, weighted kappa [kappa(w)]=0.93) and intra-(ICC=0.90, kappa(w)=0.91) observer reliability, with no evidence of observer bias. The main between score differences were for scores 0 (normal) and 1 (uneven posture and shortened stride but no head movement). The results indicate that the locomotion scoring scale using groups of defined observations for each point on the scale was reliable and may be a useful research tool to identify and monitor locomotion in individual sheep when used by trained observers.  相似文献   

Review of climate change impacts on marine aquaculture in the UK and Ireland     

Ruth Callaway  Andrew P. Shinn  Suzanne E. Grenfell  James E. Bron  Gavin Burnell  Elizabeth J. Cook  Margaret Crumlish  Sarah Culloty  Keith Davidson  Robert P. Ellis  Kevin J. Flynn  Clive Fox  Darren M. Green  Graeme C. Hays  Adam D. Hughes  Erin Johnston  Christopher D. Lowe  Ingrid Lupatsch  Shelagh Malham  Anouska F. Mendzil  Thom Nickell  Tom Pickerell  Andrew F. Rowley  Michele S. Stanley  Douglas R. Tocher  James F. Turnbull  Gemma Webb  Emma Wootton  Robin J. Shields 《水产资源保护:海洋与淡水生态系统》2012,22(3):389-421

Climate-change Mitigation and European Land-use Policies,edited by W. N. Adger,D. Pettenella and M. Whitby. CAB International,Wallingford, 1997. ISBN 0-85199-185-8, £49.95 (hardback) xvi+350 pp.     

C. Green 《Land Degradation \u0026amp; Development》1999,10(5):501-502

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