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1.
Current distribution of sarcoptic mange in wombats   总被引:2,自引:0,他引:2  
Objective To determine the distribution and prevalence of sarcoptic mange in wombats, particularly the common wombat ( Vombatus ursinus ).
Design Questionnaire survey in two parts.
Procedure Questionnaires were distributed to biologists, rangers, animal carers and naturalists. Part 1 of the questionnaire aimed to determine the present distribution of sarcoptic mange in wombats (103 responses). Part 2 invited respondents to assess the prevalence of sarcoptic mange in wombats over a 3 month period (four responses). Information on wombats from 66 localities was received. Each locality represented an area of about 2500 km2.
Results Mange was observed at 93% of localities surveyed and Sarcoptes scabiei was present in common wombats at 52% of localities. Sarcoptic mange was highly prevalent (22%) in two common wombat populations in Victoria. Anecdotal evidence suggested that mange epizootics are sporadic, cause significant morbidity and mortality and have a substantial effect on local abundance. The respondents did not report sarcoptic mange in either northern hairy-nosed wombats ( Lasiorhinus krefftii ) or southern hairy-nosed wombats ( Lasiorhinus latifrons ).
Conclusions Sarcoptic mange occurs in common wombat populations throughout the range of the common wombat including Tasmania and Flinders Island. While mange epizootics are sporadic, they have the potential to threaten the long-term survival of small, remnant populations.  相似文献   
2.
Two separate analyses were carried out to understand the epidemiology of Bluetongue virus serotype 8 (BTV-8) in 2007 in North West Europe: First, the temporal change in transmission rates was compared to the evolution of temperature during that season. Second, we evaluated the spatio-temporal dynamics of newly reported outbreaks, to estimate a spatial transmission kernel. For both analyses, the approach as used before in analysing the 2006 BTV-8 epidemic had to be adapted in order to take into account the fact that the 2007 epidemic was not a newly arising epidemic, but one advancing from whereto it had already spread in 2006. We found that within the area already affected by the 2006 outbreak, the pattern of newly infected farms in 2007 cannot be explained by between-farm transmission, but rather by local re-emergence of the virus throughout that region. This indicates that persistence through winter was ubiquitous for BTV-8. Just like in 2006, we also found that the temperature at which the infection starts to spread lies close to 15 °C. Finally, we found that the shape of the transmission kernel is in line with the one from the 2006 epidemic. In conclusion, despite the substantial differences between 2006 and 2007 in temperature patterns (2006 featured a heat wave in July, whereas 2007 was more regular) and spatial epidemic extent, both the minimum temperature required for transmission and the transmission kernel were similar to those estimated for the 2006 outbreak, indicating that they are robust properties, suitable for extrapolation to other years and similar regions.  相似文献   
3.
Spatial Variability of Turbulent Mixing in the Abyssal Ocean   总被引:3,自引:0,他引:3  
Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.  相似文献   
4.
BOOK REVIEW     
ECG Interpretation in Dogs and Cats, Video produced by Provet for the Unit of Veterinary Continuing Education of the Royal Veterinary College  相似文献   
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Based on isolations from naturally infected fish in Florida, we investigated the role of the fungi Aphanomyces invadans, Achlya bisexualis, and Phialemonium dimorphosporum in the etiology of ulcerative mycosis (UM) in striped mullet Mugil cephalus. We injected healthy striped mullet subcutaneously with secondary zoospores of four oomycete isolates: two concentrations (50 and 115 zoospores/mL) of SJR (an endemic isolate of Aphanomyces invadans in American shad Alosa sapidissima from the St. Johns River); two concentrations each of CAL (25 and 65 zoospores/mL) and ACH (1,400 and 2,000 zoospores/mL; endemic isolates of Aphanomyces invadans and Achlyva bisexualis, respectively, in striped mullet from the Caloosahatchee River); and two concentrations of the ascomycete culture MTZ (2,500 and 3,500 zoospores/mL; endemic isolate of P. dimorphosporum from whirligig mullet M. gyrans in the Matanzas Inlet). All fish injected with either concentration of SJR developed granulomatous ulcers after 8 d and died within 21 d. Eighty percent (8/10) of fish injected with the high dose of CAL developed ulcers after 13 d and died within 28 d, but only 30% (3/10) of fish injected with the low dose of CAL developed ulcers. Four of the ulcerated fish died within 28 d, and the remaining fish were terminated after 32 d. Fish injected with zoospores of Aphanomyces invadans developed ulcers that were grossly and histologically similar to those observed in naturally infected striped mullet with UM from several estuaries or rivers in Florida. These hemorrhagic skin ulcers were characterized by myonecrosis and the presence of mycotic granulomas. None of the fish injected with ACH, MTZ, or sterile water developed ulcers. This study fulfilled Koch's postulates and demonstrated that ulcers could be experimentally induced in striped mullet after exposure via injection to secondary zoospores of an endemic Florida strain of Aphanomyces invadans.  相似文献   
8.
Fossils discovered in Lower Cretaceous (Aptian) rocks in the Tenere Desert of central Niger provide new information about spinosaurids, a peculiar group of piscivorous theropod dinosaurs. The remains, which represent a new genus and species, reveal the extreme elongation and transverse compression of the spinosaurid snout. The postcranial bones include blade-shaped vertebral spines that form a low sail over the hips. Phylogenetic analysis suggests that the enlarged thumb claw and robust forelimb evolved during the Jurassic, before the elongated snout and other fish-eating adaptations in the skull. The close phylogenetic relationship between the new African spinosaurid and Baryonyx from Europe provides evidence of dispersal across the Tethys seaway during the Early Cretaceous.  相似文献   
9.
Effects of small population size and reduced genetic variation on the viability of wild animal populations remain controversial. During a 35-year study of a remnant population of greater prairie chickens, population size decreased from 2000 individuals in 1962 to fewer than 50 by 1994. Concurrently, both fitness, as measured by fertility and hatching rates of eggs, and genetic diversity declined significantly. Conservation measures initiated in 1992 with translocations of birds from large, genetically diverse populations restored egg viability. Thus, sufficient genetic resources appear to be critical for maintaining populations of greater prairie chickens.  相似文献   
10.
Hunting behavior of a marine mammal beneath the antarctic fast Ice   总被引:1,自引:0,他引:1  
The hunting behavior of a marine mammal was studied beneath the Antarctic fast ice with an animal-borne video system and data recorder. Weddell seals stalked large Antarctic cod and the smaller subice fish Pagothenia borchgrevinki, often with the under-ice surface for backlighting, which implies that vision is important for hunting. They approached to within centimeters of cod without startling the fish. Seals flushed P. borchgrevinki by blowing air into subice crevices or pursued them into the platelet ice. These observations highlight the broad range of insights that are possible with simultaneous recordings of video, audio, three-dimensional dive paths, and locomotor effort.  相似文献   
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