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排序方式: 共有443条查询结果,搜索用时 31 毫秒
381.
Adam Tomasz Sikora Erlend Nybakk Rajat Panwar 《Scandinavian Journal of Forest Research》2016,31(1):119-125
This study examines the role of entrepreneurial orientation (EO) and learning orientation (LO) in the financial success of forest contracting firms. Both EO and LO have previously been understood to positively affect a firm's financial performance, but extant literature has not considered those links in a transition economy. Partially addressing this gap, we execute this study in a Polish context. Using data obtained through a mail survey of 101 owners of forest contracting firms (34% response rate), we found that both EO and LO have a positive and significant effect on financial performance. 相似文献
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384.
Pharmacokinetic‐pharmacodynamic modelling of intravenous buprenorphine in conscious horses 下载免费PDF全文
Emma J Love Ludovic Pelligand Polly M Taylor Joanna C Murrell John W Sear 《Veterinary anaesthesia and analgesia》2015,42(1):17-29
ObjectiveDescribe the pharmacokinetics of buprenorphine and norbuprenorphine in horses and to relate the plasma buprenorphine concentration to the pharmacodynamic effects.Study designSingle phase non-blinded study.AnimalsSix dedicated research horses, aged 3–10 years and weighing 480–515 kg.MethodsThermal and mechanical nociceptive thresholds, heart and respiratory rates and locomotor activity were measured before and 15, 30, 45 &; 60 minutes and 2, 4, 6, 8, 12 &; 24 hours post-administration of 10 μg kg−1 buprenorphine IV. Intestinal motility was measured 1, 6, 12 &; 24 hours after buprenorphine administration. Venous blood samples were obtained before administration of buprenorphine 10 μg kg−1 IV and 1, 2, 4, 6, 10, 15, 30, 45 &; 60 minutes, and 2, 4, 6, 8, 12 &; 24 hours afterwards. Plasma buprenorphine and norbuprenorphine concentrations were measured using a liquid chromatography-tandem mass spectroscopy (LC-MS/MS) assay with solid-phase extraction. A non-compartmental method was used for analysis of the plasma concentration–time data and plasma buprenorphine concentrations were modelled against two dynamic effects (change in thermal threshold and mechanical threshold) using a simple Emax model.ResultsPlasma buprenorphine concentrations were detectable to 480 minutes in all horses and to 720 minutes in two out of six horses. Norbuprenorphine was not detected. Thermal thresholds increased from 15 minutes post-buprenorphine administration until the 8–12 hour time points. The increase in mechanical threshold ranged from 3.5 to 6.0 Newtons (median: 4.4 N); and was associated with plasma buprenorphine concentrations in the range 0.34–2.45 ng mL−1.Conclusions and clinical relevanceThe suitability of the use of buprenorphine for peri-operative analgesia in the horse is supported by the present study. 相似文献
385.
Norris JM Bell ET Hales L Toribio JA White JD Wigney DI Baral RM Malik R 《Journal of Feline Medicine and Surgery》2007,9(4):300-308
Serum samples from 340 pet cats presented to three inner city clinics in Sydney Australia, 68 feral cats from two separate colonies in Sydney, and 329 cattery-confined pedigree and domestic cats in eastern Australia, were collected over a 2-year period and tested for antibodies directed against feline immunodeficiency virus (FIV) using immunomigration (Agen FIV Rapid Immunomigration test) and enzyme-linked immunosorbent assay methods (Snap Combo feline leukaemia virus antigen/FIV antibody test kit, IDEXX Laboratories). Western blot analysis was performed on samples in which there was discrepancy between the results. Information regarding breed, age, gender, housing arrangement and health status were recorded for all pet and cattery-confined cats, while the estimated age and current physical condition were recorded for feral cats. The FIV prevalence in the two feral cat populations was 21% and 25%. The majority of FIV-positive cats were male (60-80%). The FIV prevalence in cattery-confined cats was nil. The prevalence of FIV in the pet cat sample population was 8% (27/340) with almost equal prevalence in 'healthy' (13/170) and 'systemically unwell' (14/170) cats. The age of FIV-positive pet cats ranged from 3 to 19 years; all FIV-positive cats were domestic shorthairs with outside access. The median age of FIV-positive pet cats (11 years) was significantly greater than the median age of FIV-negative pet cats (7.5 years: P<0.05). The prevalence of FIV infection in male pet cats (21/172; 12%) was three times that in female pet cats (6/168; 4%; P<0.05). With over 80% of this pet cat population given outside access and continued FIV infection present in the feral population, this study highlights the need to develop rapid, accurate and cost-effective diagnostic methods that are not subject to false positives created by concurrent vaccination against FIV. This is especially important in re-homing stray cats within animal shelters and monitoring the efficacy of the new vaccine, which has not been challenged against Australian strains. The absence of FIV within cattery-confined cats highlights the value in routine screening and indoor lifestyles. This study provides cogent baseline FIV prevalences in three cat subpopulations which can be used for appraising potential disease associations with FIV in Australia. 相似文献
386.
Joanna Mecfel Simone Hinke Werner Andreas Goedel Günter Marx Rüdiger Fehlhaber Ernst Bäucker Otto Wienhaus 《植物养料与土壤学杂志》2007,170(6):769-772
The effect of fertilization with silicon (Si) compounds on accumulation of Si in wheat (Triticum aestivum L.) has been studied. Wheat plants were grown under identical growing conditions, but subjected to fertilization with various Si compounds (pyrolitic fine silica particles [aerosil®], sodium silicate, silica gel), and the Si content of the above ground plants was analyzed via X‐ray microanalysis (EDX) and atomic‐absorption spectroscopy (AAS). Silicon was predominantly deposited in the epidermis cells of the leaves and their cell walls. The efficiency of the Si compounds used as fertilizers to augment the Si content of the plants increased in the order sodium silicate > silica gel > aerosil® and thus seemed to correlate with the ease of formation of orthosilicic acid from these compounds. 相似文献
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388.
H. Tunney F. J. Sikora D. Kissel A. Wolf L. Sonon K. Goulding 《Soil Use and Management》2010,26(2):126-132
Liming is necessary for good nutrient availability and crop growth. Lime use in Ireland is now the lowest in half a century. A recent study shows that grassland mineral soils in Ireland has a mean pH of 5.4 and mean lime requirement (LR) of 9.3 t/ha ground limestone. There have been a number of studies in the USA to re-evaluate LR, but little activity in the European Union (EU) in recent years. The primary aim of our research was to compare five methods for estimating LR, which included the Shoemaker–McLean–Pratt (SMP) buffer method currently used in Ireland (IRL), the Sikora buffer method used at the University of Kentucky (UKY), Ca(OH)2 titration used at University of Georgia (UGA), the modified Mehlich buffer method used at Penn State University (PSU) and the UK RothLime model, using 57 representative grassland mineral soils from Ireland with a pH range from 4.8 to 6.6. The secondary aim was to explore an alternative to the SMP buffer that does not involve the use of toxic chemicals. The results show good agreement between the pH measured by the Irish and three US laboratories and reasonably good agreement in LR estimated by five methods. The main conclusions are: (1) a significant proportion of grassland on mineral soils in Ireland would benefit from liming to increase soil pH, (2) on average, LRs as recommended in Ireland are higher than those advised elsewhere , ( 3) the target pH in Ireland is high compared with that in other countries and should be reduced from pH 6.5 to 6.2, (4) the SMP buffer method should be replaced by a suitable alternative and, in principle, any of the four methods studied would be suitable, (5) to find the most suitable alternative for accurate LR advice it would be necessary to compare the different methods to the actual LR from incubation of representative soils with calcium hydroxide. 相似文献
389.
Bait worms: a valuable and important fishery with implications for fisheries and conservation management 下载免费PDF全文
Bait is an integral part of coastal life, but is perceived as a low‐value resource as fisheries are data‐limited, locally focussed and largely unregulated even though the ecological impacts of collection are considerable. An empirical assessment of three UK‐based ragworm fisheries combined with an analysis of published literature has produced the first global assessment of polychaete bait fisheries. The five most expensive (retail price per kg) marine species sold on the global fisheries market are polychaetes (Glycera dibranchiata, Diopatra aciculata, Nereis (Alitta) virens, Arenicola defodiens and Marphysa sanguinea). We estimate that 1600 t of N. virens per annum (worth £52 million) are landed in the UK with approximately 121 000 tonnes of polychaetes collected globally valued at £5.9 billion. Using remote closed circuit television (CCTV) cameras to monitor collectors, activity at local sites is considerable with a mean of 3.14 collectors per tide (day and night) at one site and individuals digging for up to 3 h per tide, although intensity differed seasonally and between sites. Collectors removed on average 1.4 kg of N. virens per person per hour, walking a considerable distance across the intertidal sediment to reach areas that were usually already dug. The implications of these human activity and biomass removal levels are explored in the context of fisheries and conservation management. At local, regional and national scales, polychaete bait fisheries are highly valuable, extract significant biomass and have considerable impacts; therefore, they urgently require governance equivalent to other fisheries. 相似文献
390.
Eric Gilman Jeff Gearhart Blake Price Scott Eckert Henry Milliken John Wang Yonat Swimmer Daisuke Shiode Osamu Abe S. Hoyt Peckham Milani Chaloupka Martin Hall Jeff Mangel Joanna Alfaro-Shigueto Paul Dalzell & Asuka Ishizaki 《Fish and Fisheries》2010,11(1):57-88
There is growing evidence that small-scale, coastal, passive net fisheries may be the largest single threat to some sea turtle populations. We review assessments of turtle interactions in these fisheries, and experiments on gear-technology approaches (modifying gear designs, materials and fishing methods) to mitigate turtle by-catch, available from a small number of studies and fisheries. Additional assessments are needed to improve the limited understanding of the relative degree of risk coastal net fisheries pose to turtle populations, to prioritize limited conservation resources and identify suitable mitigation opportunities. Whether gear technology provides effective and commercially viable solutions, alone or in combination with other approaches, is not well-understood. Fishery-specific assessments and trials are needed, as differences between fisheries, including in gear designs; turtle and target species, sizes and abundance; socioeconomic context; and practicality affect efficacy and suitability of by-catch mitigation methods. Promising gear-technology approaches for gillnets and trammel nets include: increasing gear visibility to turtles but not target species, through illumination and line materials; reducing net vertical height; increasing tiedown length or eliminating tiedowns; incorporating shark-shaped silhouettes; and modifying float characteristics, the number of floats or eliminating floats. Promising gear-technology approaches for pound nets and other trap gear include: replacing mesh with ropes in the upper portion of leaders; incorporating a turtle releasing device into traps; modifying the shape of the trap roof to direct turtles towards the location of an escapement device; using an open trap; and incorporating a device to prevent sea turtle entrance into traps. 相似文献