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991.
A. Márcia Barbosa Alba Estrada Ana L. Márquez Andy Purvis C. David L. Orme 《Journal of Biogeography》2012,39(8):1391-1400
Aim Chorological relationships describe the patterns of distributional overlap among species. In addition to revealing biogeographical structure, the resulting clusters of species with similar geographical distributions can serve as natural units in conservation planning. Here, we assess the extent to which temporal, methodological and taxonomical differences in the source of species’ distribution data can affect the relationships that are found. Location Western Europe. Methods We used two data sets – the Atlas of European mammals and polygon range maps from the IUCN Global Mammal Assessment – both as presence–absence data for UTM 50 km × 50 km squares. We performed pairwise comparisons among 156 species for each data set to build matrices of the similarity in distribution across species, using both Jaccard’s and Baroni‐Urbani & Buser’s indices. We then compared these similarity matrices (chorological relationships), as well as the species richness and occurrence patterns from the two data sets. Results As expected, range maps increased both the mean prevalence per species and mean species richness per grid cell in comparison to atlas data, reflecting the general view that these data types respectively over‐ and underestimate species occurrence. However, species richness and occurrence patterns in atlas and range map data were positively associated and, most importantly, the chorological relationships underlying the two data sets were highly similar. Main conclusions Despite many methodological, temporal and taxonomical differences between atlas data and range maps, the chorological relationships encountered between species were similar for both data sets. Chorological analyses can thus be robust to the data source used and provide a solid basis for analytical biogeographical studies, even over broad spatial scales. 相似文献
992.
《Comptes rendus biologies》2014,337(11):635-641
A critical investigation was conducted to find out the effect of neck blast disease on yield-contributing characters, and seed quality traits of aromatic rice in Bangladesh. Both healthy and neck-blast-infected panicles of three aromatic rice cultivars (high-yielding and local) were collected and investigated at Plant Pathology Division, Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh. All of the tested varieties were highly susceptible to neck blast disease under natural conditions, though no leaf blast symptoms appear on leaves. Neck blast disease increased grain sterility percentages, reduced grain size, yield and quality traits of seeds. The degrees of yield and seed quality reduction depended on disease severity and variety's genetic make-up. Unfilled grains were the main source of seed-borne pathogen, especially for blast in the seed lot. Transmission of blast pathogen from neck (panicle base) to seed was very poor. These findings are important, especially concerning the seed certification programme in which seed lots are certified on the basis of field inspection. Finally, controlled experiments are needed to draw more critical conclusions. 相似文献
993.
Measurements were made of the differences between sunflower and climbing hempweed leaves for development, fecundity and egg hatchability of Diacrisia casignetum Kollar. Developmental time and weight gains of sunflower-fed larvae were respectively longer and greater than those of hempweed-fed ones. The development time and weight gain, attributable to differences in host plants, were statistically heterogeneous (P<0.05-<0.10). Relative fecundity and egg hatchability of sunflower reared insects were greater than those of hempweed reared ones, and these were also statistically heterogeneous (P<0.1 and <0.05, respectively). Hempweed leaves contained relatively high titres of phenols and low ratios of proteins to phenols. Ovaries were heavier in insects reared on sunflower than on hempweed, whereas the level of phenols incorporated into the ovary was higher in insects fed on hempweed than those on sunflower. The differences in these parameters may be due to variations in nutritional quality of these hosts and incorporation of ingested phenolic materials to ovary and insect biomass.
Résumé L'étude a porté sur l'évaluation de l'influence des feuilles de tournesol (Helianthus annuus) et de Mikana cordata sur le développement, la fécondité et l'éclosion des oeufs de D. casignetum Kollaz. La durée de développement et le gain de poids sur tournesol étaient plus importants que sur M. cordata. La durée de développement était statistiquement hétérogène (P<0.05), ce qui peut être dû à des différences entre plantes. La fécondité et le taux d'éclosion chez les insectes élevés sur tournesol étaient plus élevés que ceux observés sur M. cordata, dont les résultats étaient aussi hétérogènes (P<0.1 et<0.05 respectivement). Les feuilles de M. cordata contenaient des taux relativement élevés de phénols et des rapports protéines sur phénols bas. Tout ceci suggère que les différences observées sont attribuables à des variations dans la qualité nutritive de ces hôtes et dans l'incorporation à la biomasse de l'insecte de matériaux phénologiques ingérés.相似文献
994.
Mark C. Mainwaring Ian R. Hartley Stuart Bearhop Kaat Brulez Christopher R. du Feu Gerald Murphy Kate E. Plummer Simone L. Webber S. James Reynolds D. Charles Deeming 《Journal of Biogeography》2012,39(9):1669-1677
Aim The laying of eggs and the building of a nest structure to accommodate them are two of the defining characteristics of members of the class Aves. Nest structures vary considerably across avian taxa and for many species the structure of the completed nest can have important consequences both for parents and their offspring. While nest characteristics are expected to vary adaptively in response to environmental conditions, large‐scale spatial variation in nest characteristics has been largely overlooked. Here, we examine the effects of latitudinal variation in spring temperatures on nest characteristics, including insulatory properties, and reproductive success of blue tits, Cyanistes caeruleus, and great tits, Parus major. Location Great Britain. Methods Nests and reproductive data were collected from seven study sites, spread over 5° of latitude. The nest insulatory properties were then determined before the nests were separated into nest base material and cup lining material. Results As spring temperatures increased with decreasing latitude, the mass of the nest base material did not vary in either species, while the mass of the cup lining material and nest insulatory properties decreased in both species. This suggests that in response to increasing temperatures the breeding female reduces the mass of the cup lining material, thereby maintaining an appropriate microclimate for incubating and brooding. The mean first egg date of both species advanced with decreasing latitude and increasing spring temperatures, although clutch size and brood size at hatching and fledging did not vary. Main conclusions This is the first study to demonstrate that the nest‐construction behaviour of birds varies in response to large‐scale spatial variation in ambient temperatures. Therefore, nest composition reliably indicates environmental conditions and we suggest that studies of nest structure may be sentinels for the early signs of rapid climate change. 相似文献
995.
We assessed the effects of prescribed burning and cutting on mouflon (Ovis gmelini musimon × Ovis sp.) spring habitat using an experimental design (17.28 ha) of 2 burned, 2 cut, and 2 untreated plots within a homogeneous stand dominated by heather (Erica cinerea and Calluna vulgaris). Overall, we found a shift in treated plots from ligneous species to herbaceous species with high digestive and energetic values for mouflon. We also found a consistently higher number of mouflon feeding on these treated habitats compared to untreated plots. Such effects were still apparent 4 years after habitat modifications. Our approaches could be used by managers to improve and maintain the range of mouflon populations experiencing habitat loss (e.g., woody plant encroachment) and for which the condition of an animal has often a high economical value through trophy hunting. © 2011 The Wildlife Society. 相似文献
996.
Tino Pleiner Masami Hazu Giovani Pinton Tomaleri Kurt Januszyk Robert S. Oania Michael J. Sweredoski Annie Moradian Alina Guna Rebecca M. Voorhees 《Molecular cell》2021,81(13):2693-2704.e12
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997.
998.
Per-Anders Hansson Berit Mattsson 《The International Journal of Life Cycle Assessment》1999,4(4):202-206
The shortage of data for emissions from agricultural tractors contributes to LCA results on environmental load from modern
crop production possibly having high error levels and high uncertainties.
The first part of this work describes measurements and calculations made in order to obtain operation-specific agricultural
emission data. Calculations are based on emission data measured on a standard 70 kW tractor of a widely available make. In
the second part, results from an LCI on wheat production based on traditionally used emission data are calculated and compared
with results obtained when using the emission data for specific working operations derived in part one.
One conclusion of the study is that the emission values, when related to the energy in the used fuel, show very large variations
between different driving operations. Another conclusion is that the use of the new data results in a marked reduction of
the total air emissions produced in the wheat production chain, especially for CO and HC, but also for NOx and SO2. 相似文献
999.
Ina Sternstein Monika Reissmann Dorota Maj Josef Bieniek Gudrun A. Brockmann 《Animal genetics》2014,45(4):596-599
This study aimed at the identification of genetic variations in the myostatin (MSTN) gene and testing their effects on carcass quality traits. We comparatively sequenced Giant Grey (GG) and New Zealand White (NZW) rabbits that were founders of a cross‐bred population. Alignment of our sequence data with the GenBank sequence of the rabbit MSTN gene (Ensembl Gene ID ENSOCUG00000012663) identified three single nucleotide polymorphisms (SNPs). The two novel SNPs (c.?125T>C, c.373+234G>A) and one known SNP (c.747+34C>T) were subsequently analysed for linkage with carcass composition traits in 363 F2 animals of the cross GG × NZW. Significant linkage was found between c.373+234G>A and nine carcass composition traits (P < 0.05). No significant effects were found for c.?125T>C and c.747+34C>T. Because the linked SNP is located in intron 1 and no genetic variation was found in the coding region, further investigations are necessary to understand the functional effect of the c.373+234G>A variant on the variability of the traits. 相似文献
1000.
Ralph M. Pearson 《Arts Education Policy Review》2013,114(3):98-124
Recently, state and federal legislators have emphasized teacher quality in their efforts to improve public education. Many reformers believe that merit pay may prove invaluable in attracting highly qualified educators to the workforce and retaining them, as well as in improving students’ test scores. While merit pay's ability to recruit and retain great teachers is as yet unproven, recent studies have found little evidence that merit pay improves students’ test scores. The following article seeks to inform merit pay policies by offering insight from research in educational psychology and outlining possible implications for music education. 相似文献