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461.
462.
  • 1. The Galapagos Marine Reserve provides refuge for numerous threatened marine species, including 16 mammals, birds, reptiles and fish currently recognized on the 2006 IUCN Red List of Threatened Species, plus an additional 25 endemic fish, mollusc, crustacean, echinoderm, coral and macroalgal species that comply with threatened species criteria because of declining extent of occurrence or highly‐localized ranges, and hence also qualify for inclusion on the Red List.
  • 2. Threatened marine species with restricted ranges are not randomly distributed across the archipelago but tend to co‐occur at a limited number of sites that are predominantly located in the west. Sites at which threatened species are known to persist, particularly those with a large proportion of the global population, are here identified as sites of global conservation significance — key biodiversity areas.
  • 3. The majority (27) of the 38 inshore key biodiversity areas identified are currently protected from fishing because they lie within the 17% of coastal waters that is zoned as ‘no‐take’ tourism or conservation zones. All key biodiversity areas should be protected from extractive exploitation if threatened species are to be safeguarded. This can be achieved, at the minimum, through a relatively minor amendment to the existing marine zoning scheme, whereby an additional 2% of the coastline is dedicated to conservation.
Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   
463.
Neosporosis caused by Neospora caninum has global economic, clinical, and epidemiological impacts, mainly in the cattle industry. Currently, there is no useful drug for treatment of neosporosis. This publication is the first to describe the significant benefits that artemisone has on Neospora infections both in vitro and in vivo. Artemisone is a new semi-synthetic 10-alkylamino artemisinin that is superior to other artemisinin derivatives in terms of its significantly higher antimalarial activity, its tolerance in vivo, lack of detectable neurotoxic potential, improved in vivo pharmacokinetics and metabolic stability. Low micromolar concentrations of artemisone inhibited in vitro Neospora development. Prophylactic and post-infection treatment profoundly reduced the number of infected cells and parasites per cell. In the in vivo gerbil model, a non-toxic dose prevented typical cerebral symptoms, in most animals. There were no signs of clinical symptoms and brain PCR was negative. Most treated gerbils produced high specific antibody titer and were protected against a challenge. Overall, artemisone could be considered as a future drug for neosporosis.  相似文献   
464.
The study of the immune response in several types of tumours has been rapidly increasing in recent years with the dual aim of understanding the interactions between neoplastic and immune cells and their importance in cancer pathogenesis and progression, as well as identifying targets for cancer immunotherapy. Despite being considered one of the most immunogenic tumour types, melanoma can progress in the presence of abundant lymphocytic infiltration, therefore suggesting that the immune response is not able to efficiently control tumour growth. The purpose of this study was to investigate whether the density, distribution and grade of tumour‐infiltrating lymphocytes (TILs) in 97 canine melanocytic tumours is associated with histologic indicators of malignancy and can be considered a prognostic factor in the dog. As a further step in the characterization of the immune response in melanocytic tumours, an immunohistochemical investigation was performed to evaluate the two main populations of TILs, T‐lymphocytes (CD3+) and B‐lymphocytes (CD20+). The results of our study show that TILs are present in a large proportion of canine melanocytic tumours, especially in oral melanomas, and that the infiltrate is usually mild. The quantity of CD20+ TILs was significantly associated with some histologic prognostic factors, such as the mitotic count, the cellular pleomorphism and the percentage of pigmented cells. Remarkably, a high infiltration of CD20+ TILs was associated with tumour‐related death, presence of metastasis/recurrence, shorter overall and disease‐free survival, increased hazard of death and of developing recurrence/metastasis, hence representing a potential new negative prognostic factor in canine melanocytic tumours.  相似文献   
465.
466.
This study assessed the associations between antimicrobial use and other management practices in pigs and antimicrobial resistance in generic Escherichia coli recovered from feces of weaner and finisher pigs on 39 purposefully selected farrow-to-finish farms in Ontario and 8 in British Columbia. Antimicrobials (n = 13), most frequently penicillins and tetracycline, wer dministered to different age groups of pigs on study farms through various routes of administration. Logistic regression was used to model risk factors to antimicrobial resistance in fecal E. coli of pigs for the following antimicrobials: ampicillin, apramycin, carbadox, cephalothin, chloramphenicol, kanamycin, neomycin, nitrofurantoin, spectinomycin, streptomycin, sulfamethoxazole tetracycline, and cotrimoxazole (trimethoprim and sulfamethoxazole). Use of antimicrobials in weaner pigs compared with use in finisher pigs was associated with resistance in most models. There was phenotypic evidence of different mechanisms of resistance selection, including direct selection [use of carbadox was associated with carbadox resistance (OR = 6.48)]; cross-resistance [use of spectinomycin was associated with streptomycin resistance (OR = 2.29)]; and possible co-selection [ceftiofu use was associated with tetracycline resistance (OR = 6.12)]. These results provide further evidence that use of antimicrobials in pigs selects for resistance among fecal E. coli within and between classes of antimicrobials.  相似文献   
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