Socio‐demographic drivers and public perceptions of consumption and conservation of Asian horseshoe crabs in northern Beibu Gulf,China

相似文献   

Serum chemistry of free-ranging white whales (Delphinapterus leucas) in Svalbard

BACKGROUND: Abnormal physiological conditions and diseases can change the concentrations of enzymes, metabolites, and minerals in the body. Serum chemistry information may thus be indicative of a specific disease; interpretation of such information requires knowledge of serum chemistry reference intervals from a seemingly healthy population of the species. OBJECTIVE: The aim of this study was to obtain serum chemistry reference intervals for a population of white whales. METHODS: Blood samples were collected from 21 free-ranging white whales (beluga; Delphinapterus leucas). The whales were live-captured in nets during 1996-2001 in Storfjorden, Van Mijenfjorden, and Van Keulenfjorden (Svalbard, Norway). While the whales were briefly physically restrained, blood was collected from the caudal vein into vacuum tubes without anticoagulant. The blood was left to clot for 4-6 hours before serum was obtained by centrifugation. The serum samples were then kept at -20 degrees C until analysis. Enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase [ALP], creatine kinase, lactate dehydrogenase [LDH], amylase, lipase), metabolites (urea, creatinine, bilirubin, cholesterol, triglycerides, nonesterified fatty acids, glucose), and minerals (calcium, phosphate, magnesium, sodium, potassium, chloride) were analyzed in an Advia 1650 System (Bayer, Tarrytown, NY, USA). Cortisol was analyzed in an Immulite One system (Diagnostic Products Corporation, Los Angeles, CA, USA). The major blood proteins (albumin and globulins) were separated by gel electrophoresis in a Beckman Paragon electrophoresis system (Beckman Coulter, Inc., Fullerton, CA, USA). RESULTS: Serum values for all analytes were reported as median and range, and reference intervals were calculated as 10-90th percentiles. Activities of ALP and LDH and cortisol concentration were higher, and protein and bilirubin concentrations were lower compared with those previously reported for white whales from Canada; remaining results were strikingly similar in these 2 white whale populations. CONCLUSIONS: These data provide valuable serum chemistry reference intervals for future health assessments of white whales in Svalbard and other white whale populations, as well as captive individuals.     

The nature of the 660-kilometer discontinuity in Earth's mantle from global seismic observations of PP precursors

The 660-kilometer discontinuity, which separates Earth's upper and lower mantle, has been detected routinely on a global scale in underside reflections of precursors to SS shear waves. Here, we report observations of this discontinuity in many different regions, using precursors to compressional PP waves. The apparent absence of such precursors in previous studies had posed major problems for models of mantle composition. We find a complicated structure, showing single and double reflections ranging in depth from 640 to 720 kilometers, that requires the existence of multiple phase transitions at the base of the transition zone. The results are consistent with a pyrolite mantle composition.     

Attenuated properties of thymidine kinase-negative deletion mutant of pseudorabies virus

A thymidine kinase (TK)-negative (TK-) deletion mutant of the Bucharest (BUK) strain of pseudorabies virus (PRV) was isolated. The mutant, designated as PRV (BUK d13), did not revert to TK-positive (TK+), even when propagated in medium that selected for TK+ viruses. The mutant also replicated equally well at 39.1 C and 34.5 C, and was easily distinguished from other PRV strains by molecular hybridization experiments, restriction nuclease fingerprints, and plaque autoradiography or other assays for the TK phenotype. The PRV (BUK d13) had greatly reduced virulence for mice and rabbits, compared with parental TK+ strains, PRV (BUK-5) and PRV (BUK-5A-R1), and provided mice with solid protection against the TK+ BUK and Aujeszky strains of PRV. Experiments were done in 5- to 6-week-old pigs to assess the safety and efficacy of PRV (BUK d13) in the natural host. In one experiment, pigs were vaccinated IM with 7.5 X 10(8) plaque-forming units of TK- PRV (BUK d13), and were then challenge exposed intranasally (IN) with 4.3 X 10(8) TCID50 of virulent PRV [Indiana-Funkhauser (IND-F)]. Vaccinated pigs did not have clinical signs of illness after vaccination or after challenge exposure. One nonvaccinated control pig died on postchallenge day 4; a 2nd nonvaccinated control pig became moribund, but eventually recovered. Pigs developed virus-neutralizing antibodies after vaccination, and had a secondary immunologic response after challenge exposure; however, PRV was not isolated from the tonsils or trigeminal ganglia of vaccinated pigs at postchallenge exposure day 11.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gene targeting in stem cells from individuals with osteogenesis imperfecta

Adult stem cells offer the potential to treat many diseases through a combination of ex vivo genetic manipulation and autologous transplantation. Mesenchymal stem cells (MSCs, also referred to as marrow stromal cells) are adult stem cells that can be isolated as proliferating, adherent cells from bones. MSCs can differentiate into multiple cell types present in several tissues, including bone, fat, cartilage, and muscle, making them ideal candidates for a variety of cell-based therapies. Here, we have used adeno-associated virus vectors to disrupt dominant-negative mutant COL1A1 collagen genes in MSCs from individuals with the brittle bone disorder osteogenesis imperfecta, demonstrating successful gene targeting in adult human stem cells.     

Visceral tissue vascularization: an adaptive response to high temperature

Electrical heat sources implanted in the abdominal cavities of sheep were heated to give initial temperatures of 42 degrees and 45 degrees C at the surfaces of the heaters. During 18 days of constant heating, a vascularized connective-tissue envelope encapsulated the heat sources, and the temperatures at the surfaces of the heaters declined 0.8 degrees and 1.8 degrees C, respectively. The degree of vascularization and the magnitude of the decrease in the surface temperature appeared to be related to the proximity of the tissue's initial temperature to 45 degrees C, a temperature ordinarily considered detrimental to cell structure. The vascularization thus appears to be adaptive.     

A critical analysis of the direct effects of dredging on fish

Dredging can have significant impacts on aquatic environments, but the direct effects on fish have not been critically evaluated. Here, a meta‐analysis following a conservative approach is used to understand how dredging‐related stressors, including suspended sediment, contaminated sediment, hydraulic entrainment and underwater noise, directly influence the effect size and the response elicited in fish across all aquatic ecosystems and all life‐history stages. This is followed by an in‐depth review summarizing the effects of each dredging‐related stressor on fish. Across all dredging‐related stressors, studies that reported fish mortality had significantly higher effect sizes than those that describe physiological responses, although indicators of dredge impacts should endeavour to detect effects before excessive mortality occurs. Studies examining the effects of contaminated sediment also had significantly higher effect sizes than studies on clean sediment alone or noise, suggesting additive or synergistic impacts from dredging‐related stressors. The early life stages such as eggs and larvae were most likely to suffer lethal impacts, while behavioural effects were more likely to occur in adult catadromous fishes. Both suspended sediment concentration and duration of exposure greatly influenced the type of fish response observed, with both higher concentrations and longer exposure durations associated with fish mortality. The review highlights the need for in situ studies on the effects of dredging on fish which consider the interactive effects of multiple dredging‐related stressors and their impact on sensitive species of ecological and fisheries value. This information will improve the management of dredging projects and ultimately minimize their impacts on fish.