Genetic gain in agronomic traits of common bean in the region of Planalto Catarinense     

Juliano Garcia Bertoldo  Leiri Daiane Barili  Naine Martins do Vale  Jefferson Luís Meirelles Coimbra  Diego Stähelin  Altamir Frederico Guidolin 《Euphytica》2010,171(3):381-388

The purpose of this study was to predict the genetic progress in the selection for common bean agronomic traits based on the trait expression, using two indices of adaptive selection. The existence of correlation between various traits in common bean breeding is a major restriction, but some tools that allow breeders to predict the expected gains could optimize results. The following traits were evaluated: (1) plant cycle (days), (2) plant height (in cm), (3) stem diameter (cm), (4) insertion of the first pod (cm); (5) number of pods per plant; (6) number of grains per pod; (7) pod length (cm). Results show the possibility of selecting accessions for several agronomically important traits evaluated together. The only genotype selected by both indices was UDESC 03, confirming the possibility of selecting plants with superior agronomic traits among genotypes of common bean landraces.  相似文献   

Exploring the shallows: a response to ‘Saving the shallows: focusing marine conservation where people might care’     

Stephen Fletcher  Rebecca Jefferson  Emma Mckinley 《水产资源保护:海洋与淡水生态系统》2012,22(1):7-10

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Simulation of the economic impact of transmissible gastroenteritis on commercial pig production in Australia   总被引：1，自引：0，他引：1  

BP MULLAN §  GT DAVIES†  RS CUTLER† 《Australian veterinary journal》1994,71(5):151-154

A simulation model (AUSPIG) was used to predict the effect of an increase in piglet deaths, and a reduction in growth rate and an increase in feed conversion ratio of grower pigs on the profitability of two herds representative of the Australian pig industry caused by the introduction of transmissible gastroenteritis virus (TGE) into those herds. For each herd, mortality rates for piglets under 1 week of age of 50% and 95% were assumed to represent a 'moderate' and a 'severe' outbreak, respectively. A reduction in net revenue of 70% was predicted to occur in the 6 months after a 'moderate' outbreak of TGE (100% for a 'severe' outbreak). This represents a total loss of between $260 and $330 per breeding sow in the 12 months after infection with the TGE virus. The likely financial impact of an outbreak of TGE on an Australian piggery is substantial and should be considered when addressing quarantine issues.  相似文献   

Granuloma compressing the brain of a pony     

A De Lahunta  D A Jefferson  J C Geary  J E Lowe 《The Cornell veterinarian》1970,60(4):622-639

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Purified bovine plasma blocking factor decreases Bovine leukemia virus p24 expression while increasing protein synthesis and transcriptional activity of peripheral blood mononuclear cells in short-term culture          下载免费PDF全文

Marianne J. van den Heuvel  Barbara J. Jefferson    Robert M. Jacobs 《Canadian journal of veterinary research》2005,69(3):186-192

Bovine leukemia virus (BLV) induces a persistent infection in the B-cells causing polyclonal expansion of B-cells in one-third of infected cattle and lymphosarcoma in less than 5% of infected cattle. While BLV is difficult to detect in vivo, it is readily produced by cultured lymphocytes and is diminished when supplemented by bovine plasma. This phenomenon is attributed to a poorly characterized plasma blocking factor (PBF). We assessed the effects of bovine plasma on cell viability and BLV p24 expression, and the effects of purified PBF on protein synthesis and gene expression of short-term cultures of bovine lymphocytes. The addition of 25% plasma or semi-purified PBF to cultures had no significant effect on cell viability but caused significant decreases in BLV p24 production and significantly increased de novo protein synthesis. Utilizing a human microarray, the RNA messages of 83 genes involved in cell division, cell metabolism, and gene regulation were up-regulated.  相似文献   

Distribution of Selected Timber Species of a Central African Rain Forest in Relation to Topography and Soil Heterogeneity: Implications for Forest Management     

Vincent Medjibe  Jefferson S. Hall  D. J. Harris 《Journal of Sustainable Forestry》2013,32(5):343-359

Several studies have looked at the relative importance of habitat association of tree species in maintaining tropical tree species diversity at a variety of scales including the importance of edaphic factors. The objective of this study was to test hypotheses on the distribution of important timber species in relation to topographic position and soil chemical parameters. Tree species from a Central African rain forest were selected within a 100-ha plot in southwestern Central Africa Republic. Individuals of Lovoa trichilioides, Nesogordonia papaverifera, Pterocarpus soyauxii, Terminalia superba ≥ 10 cm diameter at breast height (dbh) were inventoried then mapped to topography using a survey laser. A torus translation was performed to test for associations between tree species distribution and topographic position as well as soil mineral nutrients for three of the four species. Trees ≥ 30 cm dbh of all three species showed no association with topographic position. However, the distribution of T. superba was significantly associated with high concentrations of soil mineral nutrients. Evidence from mineral nutrient levels indicates that extrapolating topography to define habitat and soil type can be very misleading. Because many of Central Africa's most important timber species have distributions linked to edaphic factors, it is clear that soils must be considered equally as much as topographic position for management plans of logging concessions within Central African tropical forests.  相似文献   

Liquid carbon, carbon-glass beads, and the crystallization of carbon nanotubes     

de Heer WA  Poncharal P  Berger C  Gezo J  Song Z  Bettini J  Ugarte D 《Science (New York, N.Y.)》2005,307(5711):907-910

The formation of carbon nanotubes in a pure carbon arc in a helium atmosphere is found to involve liquid carbon. Electron microscopy shows a viscous liquid-like amorphous carbon layer covering the surfaces of nanotube-containing millimeter-sized columnar structures from which the cathode deposit is composed. Regularly spaced, submicrometer-sized spherical beads of amorphous carbon are often found on the nanotubes at the surfaces of these columns. Apparently, at the anode, liquid-carbon drops form, which acquire a carbon-glass surface due to rapid evaporative cooling. Nanotubes crystallize inside the supercooled, glass-coated liquid-carbon drops. The carbon-glass layer ultimately coats and beads on the nanotubes near the surface.  相似文献   

Spatial Response of Mammals to Late Quaternary Environmental Fluctuations     

RW Graham  EL Lundelius  MA Graham  EK Schroeder  RS Toomey  E Anderson  AD Barnosky  JA Burns  CS Churcher  DK Grayson  RD Guthrie  CR Harington  GT Jefferson  LD Martin  HG McDonald  RE Morlan  HA Semken  SD Webb  L Werdelin  MC Wilson 《Science (New York, N.Y.)》1996,272(5268):1601-1606

Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene.  相似文献   

MOUNT PELEE     

Jefferson MS 《Science (New York, N.Y.)》1903,17(440):909-910

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Porcine β1,4-Galactosyltransferase-I Sequence and Expression     

EA Landers  HR Burkin  GT Bleck  L Howell-Skalla  DJ Miller 《Reproduction in domestic animals》2009,44(2):228-234

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