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排序方式: 共有774条查询结果,搜索用时 78 毫秒
731.
Stuart E. Bunn 《Forest Ecology and Management》1983,6(2):169-177
Fourteen species of termites are recorded from the Wagerup-Willowdale region, Western Australia. Nine species known to occur in the northern jarrah forest, which were rare or absent in this study, occur more commonly on the coastal sand plain or further inland.Of those species of termites which are widespread in this region, two are considered to be of particular importance to the rehabilitation of bauxite mined areas. These are Amitermes obeuntis Silvestri and Coptotermes acinaciformis raffrayi Wasmann. Both of these species have been found in rehabilitated areas.No obvious associations of termite species with either upland or lowland jarrah forest were found. 相似文献
732.
B P Stuart S S Nicholson J B Smith 《Journal of the American Veterinary Medical Association》1975,167(10):949-950
Twenty-two young cows died or were euthanatized after intoxication associated with ingestion of redroot pigweed (Amaranthus retroflexus) growing in marginal grass pasture. After several days of weakness and posterior incoordination, the cattle became recumbent but remained alert. Pertinent clinical laboratory findings included increased blood urea nitrogen content and marked proteinuria. At necropsy, perirenal edema and toxic tubular neprosis were seen. 相似文献
733.
734.
Five spontaneous extracranial canine neoplasms studied by a computed tomography whole body scanner are presented: an undifferentiated sarcoma of the scapula, a mast cell sarcoma of the hip, a mast cell sarcoma of the neck, a fibrosarcoma of the neck, and a malignant melanoma of the gingiva. Computed tomography enables accurate detection and definition of tumor size and extent and is, therefore, an aid to diagnostic evaluation, therapy, and prognosis. 相似文献
735.
Douglas H. Slatter J. D. Lavach † Glenn A. Severin† Stuart Young† 《The Journal of small animal practice》1977,18(12):757-772
ABSTRACT
The characteristics of 463 cases of Überreiter's Syndrome are presented. Over 80% of the diagnoses were made in German Shepherds. A treatment regimen utilizing combinations of corticosteroids, irradiation, superficial keratectomy and partial penetrating keratoplasty is outlined. An hypothesis that ultraviolet radiation is involved in the pathogenesis of this syndrome is proposed for further testing. 相似文献
The characteristics of 463 cases of Überreiter's Syndrome are presented. Over 80% of the diagnoses were made in German Shepherds. A treatment regimen utilizing combinations of corticosteroids, irradiation, superficial keratectomy and partial penetrating keratoplasty is outlined. An hypothesis that ultraviolet radiation is involved in the pathogenesis of this syndrome is proposed for further testing. 相似文献
736.
737.
Abstract The False Thornveld of the Eastern Cape experienced a particularly intense drought during the 1982/83 growing season. Extensive grass mortality took place during the drought. After the drought, recovery was particularly sensitive to the post‐drought management treatment applied. Veld that was grazed immediately after the drought recovered far more slowly than veld that was rested. This effect was still evident three years later, illustrating the considerable importance of resting semi‐arid grassveld after a drought. Increaser I grass species present were apparently more capable of surviving drought than the Decreaser species, which in turn were more stable than the Increaser II species. Their ability to recover after the drought followed an opposite trend. On this basis, the desirability of Decreaser dominated veld, in situations that are likely to be poorly managed, is questioned. 相似文献
738.
Stuart J. DAWSON Tracey L. KREPLINS Malcolm S. KENNEDY Juanita RENWICK Mark A. COWAN Patricia A. FLEMING 《Integrative zoology》2023,18(2):299-315
Rangelands worldwide have been subject to broadscale modification, such as widespread predator control, introduction of permanent livestock water and altered vegetation to improve grazing. In Australia, these landscape changes have resulted in kangaroos (i.e. large macropods) populations increasing over the past 200 years. Kangaroos are a key contributor to total grazing pressure and in conjunction with livestock and feral herbivores have been linked to land degradation. We used 22 years of aerial survey data to investigate whether the density of 3 macropod species in the southern rangelands of Western Australia was associated with: (i) land use, including type of livestock, total livestock, density of feral goats, type of land tenure, and kangaroo commercial harvest effort; (ii) predator management, including permitted dingo control effort, estimated dingo abundance, and presence of the State Barrier Fence (a dingo exclusion fence); and (iii) environmental variables: ruggedness, rainfall, fractional cover, and total standing dry matter. Red kangaroos (Osphranter rufus) were most abundant in flat, open vegetation, on pastoral land, where area permitted for dingo control was high, and numbers were positively associated with antecedent rainfall with a 12-month delay. Western grey kangaroos (Macropus fuliginosus) were most abundant on flat, agricultural land, but less abundant in areas with high permitted dingo control. Euros (Osphranter robustus) were most abundant in rugged pastoral land with open vegetation, where permitted dingo control was high. While environmental variables are key drivers of landscape productivity and kangaroo populations, anthropogenic factors such as land use and permitted dingo control are strongly associated with kangaroo abundance. 相似文献
739.
Schipper J Chanson JS Chiozza F Cox NA Hoffmann M Katariya V Lamoreux J Rodrigues AS Stuart SN Temple HJ Baillie J Boitani L Lacher TE Mittermeier RA Smith AT Absolon D Aguiar JM Amori G Bakkour N Baldi R Berridge RJ Bielby J Black PA Blanc JJ Brooks TM Burton JA Butynski TM Catullo G Chapman R Cokeliss Z Collen B Conroy J Cooke JG da Fonseca GA Derocher AE Dublin HT Duckworth JW Emmons L Emslie RH Festa-Bianchet M Foster M Foster S Garshelis DL Gates C Gimenez-Dixon M Gonzalez S 《Science (New York, N.Y.)》2008,322(5899):225-230
Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action. 相似文献
740.
Lynn A Koehler KE Judis L Chan ER Cherry JP Schwartz S Seftel A Hunt PA Hassold TJ 《Science (New York, N.Y.)》2002,296(5576):2222-2225
Analysis of recombination between loci (linkage analysis) has been a cornerstone of human genetic research, enabling investigators to localize and, ultimately, identify genetic loci. However, despite these efforts little is known about patterns of meiotic exchange in human germ cells or the mechanisms that control these patterns. Using recently developed immunofluorescence methodology to examine exchanges in human spermatocytes, we have identified remarkable variation in the rate of recombination within and among individuals. Subsequent analyses indicate that, in humans and mice, this variation is linked to differences in the length of the synaptonemal complex. Thus, at least in mammals, a physical structure, the synaptonemal complex, reflects genetic rather than physical distance. 相似文献