Re: Brunfelsia     

Stokes R 《Australian veterinary journal》2008,86(7):N22

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Body temperature,activity patterns and hunting in free‐living cheetah: biologging reveals new insights     

Robyn S. HETEM  Duncan MITCHELL  Brenda A. DE WITT  Linda G. FICK  Shane K. MALONEY  Leith C. R. MEYER  Andrea FULLER 《Integrative zoology》2019,14(1):30-47

As one of the few felids that is predominantly diurnal, cheetahs (Acinonyx jubatus) can be exposed to high heat loads in their natural habitat. Little is known about long‐term patterns of body temperature and activity (including hunting) in cheetahs because long‐term concurrent measurements of body temperature and activity have never been reported for cheetahs, or, indeed, for any free‐living felid. We report here body temperature and locomotor activity measured with implanted data loggers over 7 months in 5 free‐living cheetahs in Namibia. Air temperature ranged from a maximum of 39 °C in summer to ?2 °C in winter. Cheetahs had higher (～0.4 °C) maximum 24‐h body temperatures, later acrophase (～1 h), with larger fluctuations in the range of the 24‐h body temperature rhythm (approximately 0.4 °C) during a hot‐dry period than during a cool‐dry period, but maintained homeothermy irrespective of the climatic conditions. As ambient temperatures increased, the cheetahs shifted from a diurnal to a crepuscular activity pattern, with reduced activity between 900 and 1500 hours and increased nocturnal activity. The timing of hunts followed the general pattern of activity; the cheetahs hunted when they were on the move. Cheetahs hunted if an opportunity presented itself; on occasion they hunted in the midday heat or in total darkness (new moon). Biologging revealed insights into cheetah biology that are not accessible by traditional observer‐based techniques.  相似文献   

A Study of the Oxygen Isotopic Composition of Precipitation Sulphate in Eastern Newfoundland     

Jamieson  Robyn E.  Wadleigh  Moire A. 《Water, air, and soil pollution》1999,110(3-4):405-420

The properties of stable oxygen isotopes make them useful for studying processes involved in the atmospheric oxidation of sulphur compounds. Experimental work in the 1980s reported that the formation of primary combustion sulphates by high temperature oxidation of SO2(g) to SO4 leads to δ18OSO4 values between +40 and +45‰. This study reports sulphate oxygen isotopic compositions from precipitation events collected at two sites in eastern Newfoundland. Values as high as +41.7‰ were measured in natural precipitation samples collected near a small oil-fired power plant located on the campus of Memorial University of Newfoundland in St. John's. These values are higher by 16‰ than any previously reported for precipitation in the literature and in conjunction with other chemical data implicate the power plant as the pollution source. Values from the second site (Seal Cove) were similar to previously reported ranges for precipitation, despite its proximity to a much larger oil-fired, thermal generating station, suggesting that different oxidation mechanisms were dominant there. Oxygen isotopic compositions of precipitation sulphates can be an important complementary tool to other isotopic, trace metal and meteorological analysis in the tracing of sources of atmospheric sulphur compounds.  相似文献   

Photoperiod and Soil Munition Constituent Effects on Phytoaccumulation and Rhizosphere Interactions in Boreal Vegetation     

Ryan R. Busby  Robyn A. Barbato  Carina M. Jung  Kate A. Morozova  Anthony J. Bednar  Andrew L. Bray  Jenifer M. Milam  Jared C. Smith  Karl J. Indest 《Water, air, and soil pollution》2018,229(12):380

Permafrost thaw is expected to alter biogeochemistry and hydrology, potentially increasing the mobility of soil constituents. Northern latitude boreal forests where permafrost thaw is occurring also experience extreme changes in day length during the growing season. As the effects of photoperiod on plant uptake of soil constituents or interactions with the rhizosphere are unknown, our objective was to determine these interactions with three plant species from different functional groups. A tree, forb, and grass common to military training ranges in this region were grown in soil spiked with or without lead, antimony, or 2,4-dinitrotoluene and grown under 16, 20, or 24 h of light. Plant biomass, soil constituent uptake, and rhizosphere bacterial communities were compared between treatments. Photoperiod had no effect on plant uptake of any soil constituent or on rhizosphere community, indicating that plants and their associated microbial communities adapted to this environment are resilient to extremes in photoperiod. Lead uptake was not significant in any plant species and had no effect on the rhizosphere. Antimony increased the percentage composition of Saprospirales in the rhizospheres of two of the three plants, indicating an interaction between this bacterial order and antimony. Antimony uptake by white spruce (Picea glauca) was considerable, with a mean concentration of 1731 mg kg^?1 in roots, while mean shoot concentration was only 155 mg kg^?1, indicating its potential to phytostabilize this heavy metal. Although antimony had the strongest impact on the rhizosphere bacterial community, it was also readily accumulated by the grass and tree.  相似文献   

Folate status and health behaviours in two Australian Indigenous populations in north Queensland     

Li M  McDermott R  D'Onise K  Leonard D 《Public health nutrition》2012,15(10):1959-1965

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The effect of rehabilitation of northern elephant seals (Mirounga angustirostris) on antimicrobial resistance of commensal Escherichia coli     

Stoddard RA  Atwill ER  Conrad PA  Byrne BA  Jang S  Lawrence J  McCowan B  Gulland FM 《Veterinary microbiology》2009,133(3):264-271

The aim of this study was to determine if antimicrobial drug use increases resistance of commensal gastrointensinal Escherichia coli of wild northern elephant seals (Mirounga angustirostris) treated in rehabilitation, and, if so, identify the risk factors involved. Minimum inhibitory concentration (MIC) levels of twelve antimicrobial drugs were determined for 289 E. coli isolates from 99 seals sampled at admission and 277 isolates obtained at release from rehabilitation using broth microdilution. Prevalence of E. coli antimicrobial resistance, MIC(50), MIC(90), and clustering of MIC values were determined for seals and the data were analyzed using Fisher's exact test, ordinal logistic regression and negative binomial regression. At release from rehabilitation 77.8% of the seals had antimicrobial resistant E. coli compared to 38.4% of the seals at admission. The MIC(90) for amoxicillin-clavulanic acid, chloramphenicol, enrofloxacin, ticarcillin-clavulanic acid, and trimethoprim-saulfamethoxazole were at levels considered to be sensitive at admission but they increased to levels of resistance at release. E. coli were grouped into four clusters by their MIC values, with increasing levels of resistance going from Cluster 1 to 4. A primary risk factor associated with the probability of a seal having E. coli in Clusters 3 and 4 was time in rehabilitation, regardless of whether the animal received treatment with antimicrobial drugs, suggesting nosocomial infection. The results of this study provide evidence that increased levels of hygiene and appropriate use of antimicrobial therapy might be important in the rehabilitation of wild animals to prevent rise in the prevalence of antimicrobial resistant bacteria.  相似文献   

Assessment of on-screen measurements, magnification, and calibration in digital radiography     

RL Read  CG Duncan  AD Wallace  JA Perry  FM Duerr 《Journal of the American Veterinary Medical Association》2012,241(6):782-787

Objective-To compare calibration methods for digital radiography in terms of measurement accuracy and interobserver variability. Design-Prospective study. Sample-Digital radiographic images of a 155-mm-long Steinmann pin. Procedures-Measurement of pin length on digital radiographs was determined with a 25.4-mm-diameter calibration ball and commercially available software program via 3 calibration methods (ie, no calibration, autocalibration, and manual calibration). Digital radiographs of the calibration ball and pin were obtained with each placed at various vertical heights from the table (7 heights) and horizontal distances from the center of the beam (4 distances). Measurements of pin length on digital radiographs were made by 4 observers who were blinded to the orientation of the calibration ball and pin. Results-Pin lengths obtained by each calibration method were significantly different from each other and from the true value. Manual calibration was the most accurate. There was no significant interobserver variability in measurements. There was no significant change in measurements when the calibration ball was moved horizontally, but pin length measurements changed significantly when the ball was moved vertically (away from the table) with an approximate magnification error of 1% per centimeter of distance between the calibration ball and pin. Conclusions and Clinical Relevance-For digital radiography, manual calibration is recommended to achieve the most accurate measurements. Ideally, the calibration ball should be placed at the same vertical height as the object to be measured; however, if this cannot be achieved, the magnification error can be expected to be approximately 1% per centimeter of distance.  相似文献   

Visualisation of the uptake of two model xenobiotics into bean leaves by confocal laser scanning microscopy: diffusion pathways and implication in phloem translocation     

Liu Z  Gaskin RE 《Pest management science》2004,60(5):434-439

The diffusion of two fluorescent dyes, Oregon Green 488 (Oregon Green) and Rhodamine B into the leaves of broad bean (Vicia faba L) plants was studied to simulate the foliar uptake process of pesticides. The uptake rate of these model xenobiotics into bean foliage was measured using a standard leaf surface wash-off method. Diffusion into leaf tissues was visualised in vivo by confocal laser scanning microscopy (CLSM). The moderately lipophilic dye (Rhodamine B) showed faster uptake than the hydrophilic one (Oregon Green), despite the former being a larger molecule. While no distinct channels or domains for preferential entry of any of the dyes could be detected in the cuticle layer by CLSM, two different diffusion patterns were identified for the movement of these two dyes after traversing the cuticle. Upon desorption from the cuticle, Rhodamine B diffused extensively into the vacuole of the epidermal cells. Further transport of this dye from the epidermal cells to the mesophyll cells was not observed. In contrast, Oregon Green was found in the epidermal cell walls and cytoplasm, and was also present in the mesophyll cells. Examination of the petioles of the treated leaves revealed that, once absorbed, Oregon Green moved readily out of the treated leaf, whereas Rhodamine B did not show any phloem translocation. It is proposed that these two different diffusion characters may be responsible for the contrasting phloem mobility of the two xenobiotics. The results are discussed in relation to the current knowledge on the uptake, translocation and efficacy of pesticides as influenced by their properties.  相似文献   

The interim management procedure approach for assessed stocks: Responsive management advice and lower assessment frequency     

Quang C. Huynh  Adrian R. Hordyk  Robyn E. Forrest  Clay E. Porch  Sean C. Anderson  Thomas R. Carruthers 《Fish and Fisheries》2020,21(3):663-679

Stock assessments are often used to provide management advice, such as a total allowable catch (TAC), to fishery managers. Many stocks are not assessed annually, and the TAC from the previous assessment is often maintained in years between assessments. We developed two interim management procedures (MPs) that update the estimate of current vulnerable biomass from a surveyed index of abundance to adjust the TAC from a previous assessment. These MPs differ in how they handle uncertainty in observed indices. Using closed‐loop simulation, we evaluated the two interim MPs (with 10‐ and 5‐year assessment intervals) against several “status quo” approaches: (1) an annual assessment, and (2) a stock assessment every 5 or 10 years with (a) fixed TACs or (b) projections between assessments. We evaluated performance across three life‐history types and six operating model scenarios. The interim MPs performed similarly to annual assessments in terms of trends in biomass and yield, regardless of the assessment interval of the interim MPs. The interim MPs often produced more yield than the Fixed TAC MP with 10‐year assessment intervals, for example, in depleted scenarios. The Fixed TAC MP performed more similarly to interim MPs when the assessment interval for the Fixed TAC MP was decreased to five years. The interim MPs can also perform well when circumstances arise that are not accounted for in the Projection MP. Our results show that interim MPs should be considered for infrequently assessed stocks or rebuilding stocks, and highlight potential cost savings of interim MPs over annual assessments.  相似文献   

抗猪呼吸道疾病复合症的对策     

Robyn Fleck  Chun Zhou  曹磊 《国外畜牧学(猪与禽)》2006,(4):44-45

在哥本哈根召开的国际猪兽医学会大会上,与会专家认为,人们对于猪呼吸道疾病复合症还存有一些问题,相当重要的一个问题就是:为什么与此症有关的各种病原体的种类在不同国家会不尽相同。  相似文献