A robust design mark-resight abundance estimator allowing heterogeneity in resighting probabilities     

Brett T. McClintock  Gary C. White  Kenneth P. Burnham 《Journal of Agricultural, Biological & Environmental Statistics》2006,11(3):231-248

This article introduces the beta-binomial estimator (BBE), a closed-population abundance mark-resight model combining the favorable qualities of maximum likelihood theory and the allowance of individual heterogeneity in sighting probability (p). The model may be parameterized for a robust sampling design consisting of multiple primary sampling occasions where closure need not be met between primary occasions. We applied the model to brown bear data from three study areas in Alaska and compared its performance to the joint hypergeometric estimator (JHE) and Bowden’s estimator (BOWE). BBE estimates suggest heterogeneity levels were non-negligible and discourage the use of JHE for these data. Compared to JHE and BOWE, confidence intervals were considerably shorter for the AIC_c model-averaged BBE. To evaluate the properties of BBE relative to JHE and BOWE when sample sizes are small, simulations were performed with data from three primary occasions generated under both individual heterogeneity and temporal variation in p. All models remained consistent regardless of levels of variation in p. In terms of precision, the AIC_c model-averaged BBE showed advantages over JHE and BOWE when heterogeneity was present and mean sighting probabilities were similar between primary occasions. Based on the conditions examined, BBE is a reliable alternative to JHE or BOWE and provides a framework for further advances in mark-resight abundance estimation.  相似文献   

Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans     

Brett Roberts  Aristotelis Antonopoulos  Stuart M Haslam  Alison J Dicker  Tom N McNeilly  Stephanie L Johnston  Anne Dell  David P Knox  Collette Britton 《Veterinary research》2013,44(1):111

With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection.  相似文献   

Evaluation of a local regression kriging approach for mapping apparent electrical conductivity of soil (ECa) at high resolution     

Wei Sun  Brett M. Whelan  Budiman Minasny  Alex B. McBratney 《植物养料与土壤学杂志》2012,175(2):212-220

Apparent electrical conductivity of soil (ECa) is a property frequently used as a diagnostic tool in precision agriculture, and is measured using vehicle‐mounted proximal sensors. Crop‐yield data, which is measured by harvester‐mounted sensors, is usually collected at a higher spatial density compared to ECa. ECa and crop‐yield maps frequently exhibit similar spatial patterns because ECa is primarily controlled by the soil clay content and the interrelated soil moisture content, which are often significant contributors to crop‐yield potential. By quantifying the spatial relationship between soil ECa and crop yield, it is possible to estimate the value of ECa at the spatial resolution of the crop‐yield data. This is achieved through the use of a local regression kriging approach which uses the higher‐resolution crop‐yield data as a covariate to predict ECa at a higher spatial resolution than would be prudent with the original ECa data alone. The accuracy of the local regression kriging (LRK) method is evaluated against local kriging (LK) and local regression (LR) to predict ECa. The results indicate that the performance of LRK is dependent on the performance of the inherent local regression. Over a range of ECa transect survey densities, LRK provides greater accuracy than LK and LR, except at very low density. Maps of the regression coefficients demonstrated that the relationship between ECa and crop yield varies from year to year, and across a field. The application of LRK to commercial scale ECa survey data, using crop yield as a covariate, should improve the accuracy of the resultant maps. This has implications for employing the maps in crop‐management decisions and building more robust calibrations between field‐gathered soil ECa and primary soil properties such as clay content.  相似文献   

Family Forest Owners’ Perceptions of Landowner Assistance Programs in the USA: A Qualitative Exploration of Program Impacts on Behaviour     

Kyle Andrejczyk  Brett J. Butler  Brenton J. Dickinson  Jaketon H. Hewes  Marla Markowski-Lindsay  David B. Kittredge  Michael A. Kilgore  Stephanie A. Snyder  Paul F. Catanzaro 《Small-Scale Forestry》2016,15(1):17-28

Using data collected from a series of focus groups, this study examines how landowner assistance programs (which may include management plans, cost-share, technical assistance and advice, and education components) affect family forest owner behaviour in the USA. Not surprisingly, most owners who participated in assistance programs had pre-existing management objectives. Participation in the management plan and cost-share components was found to facilitate the stewardship of private forests by assisting and reinforcing the behaviour of those landowners who already intend to manage their land in some pre-conceived manner. Advice and educational components appeared to do more in terms of introducing owners to new ideas. The mix of components offered as part of a landowner assistance program should consider the goals of the program and which components will be most effective in achieving those goals.  相似文献   

Changes in the minimum alveolar concentration of isoflurane and some cardiopulmonary measurements during three continuous infusion rates of dexmedetomidine in dogs     

Pascoe PJ  Raekallio M  Kuusela E  McKusick B  Granholm M 《Veterinary anaesthesia and analgesia》2006,33(2):97-103

OBJECTIVE: To measure the change in the minimum alveolar concentration of isoflurane associated with three constant rate infusions of dexmedetomidine. STUDY DESIGN: Prospective, randomized, and blinded experimental trial. Animals Six healthy 6-year-old Beagles weighing between 13.0 and 17.7 kg. METHODS: The dogs received each of four treatments; saline or dexmedetomidine at 0.1, 0.5 or 3 microg kg(-1) loading dose given intravenously (IV) over 6 minutes followed by infusions at 0.1, 0.5 or 3 microg kg(-1) hour(-1), respectively. There were 2 weeks between treatments. The dogs were mask-induced with and maintained on isoflurane in oxygen. Acetated Ringer's (5 mL kg(-1) hour(-1)) and saline or dexmedetomidine (each at 0.5 mL kg(-1) hour(-1)) were given IV. Pulse rate, blood pressure, samples for the measurement of blood gases, pH, lactate, packed cell volume (PCV), total protein (TP) and dexmedetomidine concentrations were obtained from an arterial catheter. Sixty minutes after induction minimum alveolar concentration (MAC) was determined by intermittently applying supramaximal electrical stimuli to the thoracic and pelvic limbs. Cardiopulmonary measurements and arterial blood samples were collected before each set of stimuli. Statistical analyses were conducted with analysis of variance or mixed models according to the experimental design. RESULTS: There was a significant decrease in the MAC of isoflurane associated with 0.5 and 3 microg kg(-1) hour(-1) but not with 0.1 mg kg(-1)hour(-1). Serum concentrations of dexmedetomidine were not measurable at the 0.1 mg kg(-1) hour(-1) and averaged 0.198 +/- 0.081 and 1.903 +/-0.621 ng mL(-1) for the 0.5 and 3 microg kg(-1) hour(-1) infusion rates, respectively. Heart rate decreased with increasing doses of dexmedetomidine while blood pressure increased. Packed cell volume increased at 3 microg kg(-1) hour(-1) but not with other doses. CONCLUSIONS AND CLINICAL RELEVANCE: Dexmedetomidine infusions decrease the intra-operative requirement for isoflurane and may be useful in managing dogs undergoing surgery, where the provision of analgesia and limitation of the stress response is desirable.  相似文献   

Agreement between the caudal fold test and serological tests for the detection of Mycobacterium bovis infection in bison     

Chapinal N  Elkin BT  Joly DO  Schumaker BA  Stephen C 《Preventive veterinary medicine》2012,105(4):326-330

The objective of this study was to estimate agreement between the caudal fold test (CFT) and different serological tests for the detection of Mycobacterium bovis infection in bison by using prevalence-adjusted bias-adjusted kappa (PABAK). A total of 212 of wild wood bison from Wood Buffalo National Park were tested with the CFT as well as several serological tests: fluorescent polarization assay (FPA), multiantigen print immunoassay (MAPIA), rapid lateral-flow test (RT) and dual path platform test (DPP). For RT, 3 variations were conducted using 30μl of serum (RT 30), 20μl of serum (RT 20) and 20μl of serum considering only a strong reaction as positive (RT 20 ST). The McNemar's χ(2) test was conducted to assess whether the proportion of positive test results to 2 different tests differed. Two measures of agreement between pair of tests were estimated: the Cohen's kappa statistic and PABAK. The apparent prevalence of tuberculosis in the sampled animals varied depending on the diagnostic test from 6.1% (FPA and DPP) to 47.2% (CFT). The prevalence estimated by CFT differed from the prevalence estimated by the other tests, whereas the prevalence estimated by FPA, MAPIA, RT 20 ST and DPP were not significantly different. The kappa and PABAK estimates calculated between CFT and the rest of the tests suggested poor to slight agreement between tests (k and PABAK<0.25 in all cases). The PABAK estimates for the pairwise combinations among serological tests were numerically greater than the kappa estimates (and significantly greater when FPA was compared to the rest of serological tests), and suggested substantial to almost perfect agreement (PABAK>0.75 in all cases). The disagreement between the skin and serological tests for the detection of M. bovis infection could be partly because the tests measure different immunological responses (cell-mediated vs. humoral) that are predominant at different stages of the infection, and partly due to inaccuracy of the tests. Further research is needed to evaluate the accuracy of diagnostic tests in order to establish a reliable case definition, combining different tests, to be used in the surveillance and control of tuberculosis in free-ranging bison populations.  相似文献   

Effect of <Emphasis Type="Italic">Acrocomia aculeata</Emphasis> Kernel Oil on Adiposity in Type 2 Diabetic Rats     

Ângela A. Nunes  Danieli F. Buccini  Jeandre A. S. Jaques  Luciane C. Portugal  Rita C. A. Guimarães  Simone P. Favaro  Ruy A. Caldas  Cristiano M. E. Carvalho 《Plant foods for human nutrition (Dordrecht, Netherlands)》2018,73(1):61-67

The macauba palm (Acrocomia aculeata) is native of tropical America and is found mostly in the Cerrados and Pantanal biomes. The fruits provide an oily pulp, rich in long chain fatty acids, and a kernel that encompass more than 50% of lipids rich in medium chain fatty acids (MCFA). Based on biochemical and nutritional evidences MCFA is readily catabolized and can reduce body fat accumulation. In this study, an animal model was employed to evaluate the effect of Acrocomia aculeata kernel oil (AKO) on the blood glucose level and the fatty acid deposit in the epididymal adipose tissue. The A. aculeata kernel oil obtained by cold pressing presented suitable quality as edible oil. Its fatty acid profile indicates high concentration of MCFA, mainly lauric, capric and caprilic. Type 2 diabetic rats fed with that kernel oil showed reduction of blood glucose level in comparison with the diabetic control group. Acrocomia aculeata kernel oil showed hypoglycemic effect. A small fraction of total dietary medium chain fatty acid was accumulated in the epididymal adipose tissue of rats fed with AKO at both low and high doses and caprilic acid did not deposit at all.  相似文献   

Farmers’ perceptions of coexistence between agriculture and a large scale coal seam gas development     

Neil I. Huth  Brett Cocks  Neal Dalgliesh  Perry L. Poulton  Oswald Marinoni  Javier Navarro Garcia 《Agriculture and Human Values》2018,35(1):99-115

The Coal Seam Gas (CSG) extraction industry is developing rapidly within the Surat Basin in southern Queensland, Australia, with licenses already approved for tenements covering more than 24,000 km². Much of this land is used for a broad range of agricultural purposes and the need for coexistence between the farm and gas industries has been the source of much conflict. Whilst much research has been undertaken into the environmental and economic impacts of CSG, little research has looked into the issues of coexistence between farmers and the CSG industry in the shared space that is a farm business, a home and a resource extraction network. We conducted three workshops with farmers from across a broad region undergoing CSG development to explore farmers’ perceptions of some of the issues arising from large scale land use change. Workshops explored the importance of place identity and landscape aesthetics for farmers, farmers’ acceptance and coping with change, and possible benefits from off-farm income. We found that farmers believed that place identity was not well understood by CSG staff from non-rural backgrounds and that farmers struggled to explain some concerns because of the different way they interpreted their landscape. Furthermore, high staff turnover, and the extensive use of contractors also impacted on communications. These factors were the cause of much frustration and farmers felt that this has led to severe impacts on mental health and wellbeing. Farmers felt that a change in culture within the CSG companies will be required if engagement with farmers is to improve and that efforts to employ local people in these communications was helping this. The workshops also identified a range of issues perceived by farmers arising from increased traffic volumes, impacts to mental health and wellbeing, place identity and loss of water resources for farmers. Finally, it was suggested that scientists and agricultural industry groups will need to work closely with farmers to develop understanding of these emerging issues and to develop solutions that are timely and relevant.  相似文献   

Bioaccumulation of Trace and Non-trace Elements in Blood and Fibers of Alpacas (<Emphasis Type="Italic">Vicugna pacos</Emphasis>) that Graze in Italian Pastures     

Stefania Squadrone  Maria Cesarina Abete  Marco Rizzi  Gabriella Monaco  Livio Favaro 《Water, air, and soil pollution》2018,229(2):41

The concentrations of trace and non-trace elements were determined in blood and fibers of alpacas (Vicugna pacos) from a north Italian area, as well as in their pasture forages. This is the first investigation regarding this species in Italy, and the first considering alpaca’s fiber as bioindicator worldwide. Metal contents in blood were in the decreasing order: copper?>?zinc?>?aluminum?>?selenium?>?lead?>?nickel?>?manganese?>?chromium?>?arsenic and cadmium, while in fiber, metal levels were in the following order: aluminum?>?zinc?>?copper?>?manganese?>?chromium?>?nickel?>?selenium?>?lead?>?arsenic and cadmium. Antimony, beryllium, mercury, tin, and thallium were below the limit of quantification (0.010 mg kg^?1). The analysis of the alpacas’ forage confirmed the same trend found in fiber, suggesting that metal bioaccumulation was affected by diet. These preliminary results have shown that all the trace elements studied bioaccumulated to a greater extent in the fibers of the alpaca than in the blood. Accordingly, we may suggest that alpaca fibers could be used for monitoring exposure especially to non-essential metals like aluminum, cadmium, and lead, and could constitute a suitable non-invasive method for measuring trace and non-trace element exposure in camelids.  相似文献   

Growth and fillet quality attributes of five genetic strains of rainbow trout (Oncorhynchus mykiss) reared in a partial water reuse system and harvested at different sizes          下载免费PDF全文

Curtis C Crouse  John W Davidson  Christopher M Good  Travis C May  Steven T Summerfelt  P Brett Kenney  Timothy D Leeds  Beth M Cleveland 《Aquaculture Research》2018,49(4):1672-1681

Genetics and harvest size influence fish growth performance and product quality attributes, making selection of fish strain and harvest size critical for optimizing quality. Definition of performance and quality outcomes in a recirculating aquaculture system (RAS) environment may guide selection of fish stocks best suited for RAS farmers to meet production and product quality goals. Accordingly, five genetic lines of rainbow trout, Oncorhynchus mykiss were reared to 3 kg in a partial water reuse system and sampled at common harvest sizes (0.5, 1, 2 and 3 kg) to compare growth performance and product quality attributes. Fish weight affected fish processing yields and cook yields. Genetic line affected fish weight. When correcting for fish size, differences in fillet yields due to genetic line were present. Both fish weight and genetic line affected different organ indices, fillet colour scores and mortality. Muscle composition and texture were similar at each harvest, but changed with increasing fish size over time. Differences in growth performance and product quality traits due to genetic line identify variation in available fish stocks, and balancing change to these traits due to fish size can guide producer selection of fish stocks and optimal harvest size to meet individual production goals.  相似文献