Current distribution of sarcoptic mange in wombats   总被引：2，自引：0，他引：2  

RW MARTIN  KA HANDASYDE  LF SKERRATT 《Australian veterinary journal》1998,76(6):411-414

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   

Effects of Nitrogen Rate and Harvest Moisture Content on Physicochemical Properties and Milling Yields of Rice     

Brandon C. Grigg  Terry J. Siebenmorgen  Richard J. Norman 《Cereal Chemistry》2016,93(2):172-181

Field studies were conducted from 2011 to 2013 near Stuttgart, Arkansas. The impacts of nitrogen rate (0, 45, 90, 135, and 180 kg of N/ha) and harvest moisture content (HMC) (23, 19, and 15%, wet basis) on physicochemical properties and milling yields were determined. Trends were similar for the cultivars evaluated: Cheniere, CL XL745, and Wells. Milled rice yields were only minimally impacted by either N rate or HMC level. Increasing N rate reduced kernel length and thickness of brown rice, chalkiness of brown rice and head rice, and viscosities of head rice flour, and it increased brown rice and head rice crude protein content and head rice yield (HRY). In terms of milling yields and head rice functionality, these data suggest that N rates as low as 90 kg of N/ha could be utilized, should production recommendations be changed. Significant interactions between N rate and HMC level were infrequent and were associated with the 0 kg of N/ha rate, unrealistic for rice production. Decreasing HMC from 23 to 19% reduced kernel length and thickness and increased crude protein content and chalkiness; further decreasing HMC to 15% also increased kernel fissuring and decreased HRY.  相似文献   

Confirmation of spatial patterns and temperature effects in Bluetongue virus serotype-8 transmission in NW-Europe from the 2007 reported case data     

Gert Jan Boender  Thomas J Hagenaars  Armin RW Elbers  J?rn M Gethmann  Estelle Meroc  Helene Guis  Aline A de Koeijer 《Veterinary research》2014,45(1)

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   

Success and virulence in Toxoplasma as the result of sexual recombination between two distinct ancestries     

Grigg ME  Bonnefoy S  Hehl AB  Suzuki Y  Boothroyd JC 《Science (New York, N.Y.)》2001,294(5540):161-165

Toxoplasma gondii is a common human pathogen causing serious, even fatal, disease in the developing fetus and in immunocompromised patients. Despite its ability to reproduce sexually and its broad geographic and host range, Toxoplasma has a clonal population structure comprised principally of three lines. We have analyzed 15 polymorphic loci in the archetypal type I, II, and III strains and found that polymorphism was limited to, at most, two rather than three allelic classes and no polymorphism was detected between alleles in strains of a given type. Multilocus analysis of 10 nonarchetypal isolates likewise clustered the vast majority of alleles into the same two distinct ancestries. These data strongly suggest that the currently predominant genotypes exist as a pandemic outbreak from a genetic mixing of two discrete ancestral lines. To determine if such mixing could lead to the extreme virulence observed for some strains, we examined the F(1) progeny of a cross between a type II and III strain, both of which are relatively avirulent in mice. Among the progeny were recombinants that were at least 3 logs more virulent than either parent. Thus, sexual recombination, by combining polymorphisms in two distinct and competing clonal lines, can be a powerful force driving the natural evolution of virulence in this highly successful pathogen.  相似文献   

Spatial Variability of Turbulent Mixing in the Abyssal Ocean   总被引：3，自引：0，他引：3  

KL Polzin  JM Toole  JR Ledwell  RW Schmitt 《Science (New York, N.Y.)》1997,276(5309):93-96

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   

Paleoceanography of coral reefs in the hawaiian-emperor chain     

Grigg RW 《Science (New York, N.Y.)》1988,240(4860):1737

The fossil record of shallow marine organisms in the Hawaiian Archipelago and Emperor seamount chain indicates that reef corals were absent during the first half of the Tertiary. Their appearance during the early Oligocene, 34 million years ago, is associated with several paleoceanographic events that appear to have combined to intensify gradually gyral surface currents in the north Pacific. This association suggests that corals were absent in the early Tertiary because of isolation of the Hawaiian Archipelago from the Indo-West Pacific (IWP), the center of reef coral abundance and diversity in the Pacific. Today, the number of species of reef corals in Hawaii is less than 10 percent of the number of species in the IWP. Since their initial colonization, reef corals have been present continuously in the Hawaiian Archipelago, although not without taxonomic change. Episodes of extinction and recolonization are the most likely cause of change in species composition. Recolonization from the IWP may also explain the low rate of endemism (about 20 percent) in the present-day coral fauna.  相似文献   

BOOK REVIEW     

RW Mitten 《Australian veterinary journal》1992,69(6):139-139

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   

Serological evidence for the presence of Leptospira interrogans serovar bratislava in Australian pigs     

RJ RICHAPPEL  WA ELLIS†  B ADLER‡  L AMON  BD MILLAR§  SS ZHU  RW PRIM§ 《Australian veterinary journal》1992,69(5):119-120

  相似文献   

Timothy Charles Roberts     

RW Gee 《Australian veterinary journal》1994,71(11):392-392

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Transplacental toxoplasmosis in a wild southern sea otter (Enhydra lutris nereis)     

Miller M  Conrad P  James ER  Packham A  Toy-Choutka S  Murray MJ  Jessup D  Grigg M 《Veterinary parasitology》2008,153(1-2):12-18

In September 2004, a neonatal sea otter pup was found alive on the beach in northern Monterey Bay, CA. Efforts to locate the mother were unsuccessful. Due to a poor prognosis for successful rehabilitation, the pup was euthanized. Postmortem examination revealed emaciation, systemic lymphadenopathy and a malformation of the left cerebral temporal lobe. On histopathology, free tachyzoites and tissue cysts compatible with Toxoplasma gondii were observed in the brain, heart, thymus, liver, lymph nodes and peri-umbilical adipose. The presence of T. gondii within host tissues was associated with lymphoplasmacytic inflammation and tissue necrosis. Immunofluorescent antibody tests using postmortem serum were positive for anti-T. gondii IgM and IgG (at 1:320 and 1:1280 serum dilution, respectively), but were negative for IgG directed against Sarcocystis neurona and Neospora caninum (<1:40 each). Brain immunohistochemistry revealed positive staining for tachyzoites and tissue cysts using antiserum raised to T. gondii, but not S. neurona or N. caninum. T. gondii parasite DNA was obtained from extracts of brain and muscle by PCR amplification using the diagnostic B1 locus. Restriction enzyme digestion followed by gel electrophoresis and DNA sequencing confirmed the presence of Type X T. gondii, the strain identified in the majority of southern sea otter infections.  相似文献