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51.
Digestion rates were determined for natural prey items offered to each of seven species of sea anemones found at Wooley’s Pool in False Bay and to the single species (Bunodactis reynaudi) recorded at Biouberg on the Atlantic coast of the south-western Cape, South Africa.This was done by examining prey items removed from the coelenterons at regular intervals after feeding and assessing their degree of digestion according to a predetermined scale. There was considerable variation in the gut retention times between different anemone species offered the same prey types, with Actinia equina consistently showing the shortest gut retention times (12 h for amphipods, 15 h for pelecypods and 23 h for isopods). Of the various prey categories tested, amphipods tended to be the most rapidly digested group, while molluscs and echinoderms usually remained in the coelenteron the longest. Mean gut retention times in B. reynaudi, the only species found both in False Bay (17°C) and on the cold west coast (12°C) were markedly longer (72 vs 60 h and 43 vs 30 h for pelecypods and gastropods respectively) at the lower temperature. 相似文献
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A standard postmortem protocol, consisting of gross pathology, culture for mycobacteria and limited selective histopathology, was used in the randomised badger culling trial in Great Britain to detect Mycobacterium bovis infection. This standard protocol was compared with a more detailed protocol in which more tissues were examined grossly, more tissues were cultured, more culture slopes were seeded, the culture period was extended and tissues were examined routinely by histopathology. The standard protocol was more sensitive in badgers with gross visible lesions than in badgers with no gross visible lesions. When applied to the study population of badgers, the overall sensitivity of the standard protocol relative to the more detailed protocol was estimated to be 54.6 per cent (95 per cent confidence interval 44.9 to 69.8 per cent). Badgers with tuberculosis (tb) detected by the standard protocol had a mean of 7.6 tissues with microscopic lesions suspicious of tb. The additional badgers detected by the detailed protocol had a mean of 4.4 tissues with microscopic lesions suspicious of tb. 相似文献
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Nitrogen and phosphorus in runoff from grassland with buffer strips following application of fertilizers and manures 总被引:6,自引:0,他引:6
Abstract. We examined whether nitrogen (N) and phosphorus (P) export was enhanced from grassland receiving inorganic fertilizer and manures typical of intensive livestock production. Buffer strips were included in the study to determine if they could reduce nutrient export. Hillslope plots receiving granular inorganic fertilizer, liquid cattle slurry and solid cattle manure (FYM) were compared using rainfall simulation for 4 storms on consecutive days at 22 mm h-1 and 35 minutes duration. The plots were hydrologically isolated in a randomized block layout of 4 treatments × 3 replicates and measured 30 × 5m; the upper 20m received either fertilizer, slurry or FYM, while the lower 10 m acted as an unfertilized grass buffer strip. Nitrogen and P export in surface runoff from grassland receiving inorganic fertilizer exceeded that from FYM or slurry treatments; concentrations up to46mgN1--1 and 15 mgP1–1 were recorded.
Sixty eight % and 62% of the N from FYM and slurry respectively, was exported in organic form. Seventy four % (FYM) and 39% (slurry) of the P was in particulate or dissolved organic form. The buffer strip reduced N export in surface runoff by 94% and P export by 98% from inorganic fertilizer plots. A 75% reduction in N export was recorded from the buffer zone below slurry plots but only a 10% reduction in P, with most P remaining in the particulate or dissolved organic fraction. There was no significant difference in N export from the buffer zone between the inorganic fertilizer treatment and the untreated control. 相似文献
Sixty eight % and 62% of the N from FYM and slurry respectively, was exported in organic form. Seventy four % (FYM) and 39% (slurry) of the P was in particulate or dissolved organic form. The buffer strip reduced N export in surface runoff by 94% and P export by 98% from inorganic fertilizer plots. A 75% reduction in N export was recorded from the buffer zone below slurry plots but only a 10% reduction in P, with most P remaining in the particulate or dissolved organic fraction. There was no significant difference in N export from the buffer zone between the inorganic fertilizer treatment and the untreated control. 相似文献
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Quantifying subjective human dimensions of recreational fishing: does good health come to those who bait?
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Shane P Griffiths Joanne Bryant Henry F Raymond Peter A Newcombe 《Fish and Fisheries》2017,18(1):171-184
Recreational fishing is a popular sport and leisure activity in many countries worldwide. There has been growing interest by recreational fishing groups and researchers in the perceived physical and psychological health and social (or ‘biopsychosocial’) benefits of recreational fishing. However, quantifying the key subjective ‘human dimensions’ of fishing that satisfy both the needs of recreational fishing groups and fishery managers is a major obstacle. We propose the use of psychometrically valid health‐related quality of life (HRQOL) measures widely used in the medical and health sciences – namely the Short‐Form Health Survey (SF‐36) – as rapid, reliable and cost‐effective instruments for quantifying HRQOL of recreational fishers. The widespread use of SF‐36 and availability of population normative data allows comparisons of the HRQOL of recreational fishers across multiple temporal and spatial scales, with participants of other activities, and the general population. The use of such measures in periodic surveys allows the biopsychosocial status of a recreational fishery's participants to be assessed using a modified Kobe plot, a graphical format that is easily interpretable and consistent with existing reporting formats used in fisheries stock assessment. Future biopsychosocial research in recreational fisheries can further benefit from interdisciplinary collaboration to develop a suite of standardized psychometrically valid and reliable instruments for assessing specific issues that commonly affect recreational fisheries from regional to international scales, such as drivers of fisher motivation, behaviour and satisfaction. 相似文献
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Hawkins SS Griffiths LJ Dezateux C Law C;Millennium Cohort Study Child Health Group 《Public health nutrition》2007,10(9):891-896
OBJECTIVE: To examine the relationship of maternal employment characteristics, day care arrangements and the type of maternity leave pay to breast-feeding for at least 4 months. DESIGN: Cohort study. SETTING: Babies aged 9 months in the Millennium Cohort Study, born between September 2000 and January 2002. SUBJECTS: A total of 6917 British/Irish white employed mothers with singleton babies. RESULTS: Mothers employed part-time or self-employed were more likely to breast-feed for at least 4 months than those employed full-time (adjusted rate ratio (aRR) and 95% confidence interval (CI) 1.30 (1.17-1.44) and 1.74 (1.46-2.07), respectively). The longer a mother delayed her return to work postpartum, the more likely she was to breast-feed for at least 4 months (P for trend < 0.001). Mothers were less likely to breast-feed for at least 4 months if they returned to work for financial reasons (aRR 0.86, 95% CI 0.80-0.93) or used informal day care arrangements rather than care by themselves or their partner (aRR 0.81, 95% CI 0.71-0.91). Mothers were more likely to breastfeed for at least 4 months if their employer offered family-friendly (aRR 1.14, 95% CI 1.02-1.27) or flexible work arrangements (aRR 1.24, 95% CI 1.00-1.55), or they received Statutory Maternity Pay (SMP) plus additional pay during their maternity leave rather than SMP alone (aRR 1.13, 95% CI 1.02-1.26). These findings were independent of confounding factors, such as socio-economic status and maternal education. CONCLUSIONS: Current policies may encourage mothers to enter or return to employment postpartum, but this may result in widening inequalities in breast-feeding and persistence of low rates. Policies should aim to increase financial support and incentives for employers to offer supportive work arrangements. 相似文献
59.
Conidia of the fungus Metarhizium flavoviride were formulated in a paraffinic oil, ‘Shellsol’ T, and sprayed using the Francome MkII exhaust nozzle sprayer. Germination of the conidia collected from the spray was reduced by 30% as compared to unsprayed conidia. However, in bioassays, there was no detectable difference in virulence with conidia collected from the spray samples and unsprayed formulation. This indicated that, despite the recorded reduction in the concentration of active conidia, the efficacy of the formulation remained unchanged after passing through the exhaust nozzle sprayer. The droplet size spectra produced by the sprayer were investigated using the Malvern series 2600cc particle size analyser. The optimum droplets for locust control produced by this sprayer were generated by the number 1 nozzle (internal diameter 2·5 mm) with the number 1 restrictor ring (internal diameter 12.5 mm) sprayed at a pressure of 0·2 bar. The droplets thus produced had a volume median diameter of 58 μm when the nozzle protruded between 1 and 2 mm above the level of the restrictor ring. Of the droplets in the spray plume created by these conditions, 33% were between 50 and 100 μm, a range recommended as an achievable optimum for the ultra-low-volume application of Metarhizium flavoviride. The role of the exhaust nozzle sprayer as a tool for the application of M. flavoviride for locust control is discussed with reference to other vehicle-mounted ultra-low-volume sprayers. © 1997 SCI 相似文献
60.
Chih‐Yu Lin Sheng‐Ping Wang Wei‐Chuan Chiang Shane Griffiths Hsin‐Ming Yeh 《Fisheries Management and Ecology》2020,27(4):345-356
An ecological risk assessment was undertaken using productivity‐susceptibility analysis (PSA) to determine the relative vulnerability of 52 species caught by fisheries in the waters off eastern Taiwan. Overall, eight and 20 species were classified as having high and moderate vulnerability, respectively, and the remaining 24 species were classified as having low vulnerability. The species with the highest vulnerability scores were caught mainly by longline and gillnet fisheries, highlighting the need for improved data collection to facilitate a more detailed investigation using more quantitative methods. The data quality analysis indicated that the quality of data was classified as “moderate” for economically important species. However, many species were considered data‐limited and thus collecting high‐resolution catch and effort information and conducting biological studies, especially relating to age, growth and reproduction, are recommended to improve the reliability of outputs from data‐limited assessments such as PSA. 相似文献