Risk Sensitivity and Hunter Perceptions of Chronic Wasting Disease Risk and Other Hunting,Wildlife, and Health Risks

This article examined relationships among hunter perceptions of personal health risks from chronic wasting disease (CWD), knowledge and information about CWD, and perceptions of other hunting, wildlife, and health risks. Data were obtained from surveys of 2,725 deer and elk hunters in Colorado. Cluster analysis grouped hunters into no (42%), slight (44%), and moderate (14%) risk groups based on perceptions of personal health risks from CWD (e.g., concern about health, become ill from CWD). There were minimal differences among groups in demographics, information sources, and knowledge about CWD. Hunters who perceived higher health risks from CWD (i.e., moderate risk), however, perceived greater risks associated with CWD to other humans, CWD to wildlife, hunting to personal health, other diseases to health, and the future of hunting. These findings illustrated the concept of risk sensitivity where hunters who perceived higher risks from CWD were predisposed to rate all other risks as large.     

Insecticidal potency of novel compounds on multiple insect species of medical and veterinary importance

BACKGROUND: Vector‐borne diseases continue to present significant threats to human, animal and plant health. Mosquitoes, houseflies, sand flies and stable flies are well‐known vectors of several human and animal pathogens. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against these insect species with the aim of developing novel insecticides toxic to multiple insect species. RESULTS: Three semiochemicals, namely beta‐damascone, cyclemone A and melafleur, showed remarkable toxicity to three mosquitoes, Aedes aegypti L., Ae. albopictus (Skuse) and Anopheles quadrimaculatus Say, the housefly, Musca domestica L., the stable fly, Stomoxys calcitrans L., and the sand fly, Lutzomyia shannoni (Dyar). The chemicals were equally toxic to several field‐collected permethrin‐tolerant housefly strains. When formulated as 500 mL L^?1 emulsifiable concentrates, the chemicals demonstrated stability and toxicity on filter paper and camouflage military fabrics, with persistence up to 8 days under laboratory conditions. The chemicals were equally effective under field conditions when evaluated on unpainted plywood panels, although a higher dosage was required under field conditions to achieve similar efficacy. CONCLUSION: Laboratory quantification of LC₅₀ values and field efficacy of three semiochemicals as formulated compounds on mosquitoes, houseflies, stable flies and sand flies showed that these semiochemicals could serve as potent insecticides for multiple insect species. Copyright © 2010 Society of Chemical Industry     

The relationship between mirex-induced liver enlargement and the adrenal glands

A single oral dose of mirex given to male rats produced a doubling in liver mass (liver weight/body weight) within 3 days. The response was both dose and time related. There was an accompanying increase in adrenal gland weight (adrenal weight/body weight). In adrenalectomized animals given a single oral dose of mirex, the increase in liver weight/body weight response was drastically reduced. Adrenalectomized animals given corticosterone supplements showed a similar liver weight increase when given mirex as did intact mirex dosed animals. These results suggest a relationship between mirex-induced liver enlargement and adrenal gland secretions.     

Protocol: High-throughput and quantitative assays of auxin and auxin precursors from minute tissue samples

ABSTRACT: BACKGROUND: The plant hormone auxin, indole-3-acetic acid (IAA), plays important roles in plant growth and development. The signaling response to IAA is largely dependent on the local concentration of IAA, and this concentration is regulated by multiple mechanisms in plants. Therefore, the precise quantification of local IAA concentration provides insights into the regulation of IAA and its biological roles. Meanwhile, pathways and genes involved in IAA biosynthesis are not fully understood, so it is necessary to analyze the production of IAA at the metabolite level for unbiased studies of IAA biosynthesis. RESULTS: We have developed high-throughput methods to quantify plant endogenous IAA and its biosynthetic precursors including indole, tryptophan, indole-3-pyruvic acid (IPyA), and indole-3-butyric acid (IBA). The protocol starts with homogenizing plant tissues with stable-labeled internal standards added, followed by analyte purification using solid phase extraction (SPE) tips and analyte derivatization. The derivatized analytes are finally analyzed by selected reaction monitoring on a gas chromatograph-mass spectrometer (GC-MS/MS) to determine the precise abundance of analytes. The amount of plant tissue required for the assay is small (typically 2--10 mg fresh weight), and the use of SPE tips is simple and convenient, which allows preparation of large sets of samples within reasonable time periods. CONCLUSIONS: The SPE tips and GC-MS/MS based method enables high-throughput and accurate quantification of IAA and its biosynthetic precursors from minute plant tissue samples. The protocol can be used for measurement of these endogenous compounds using isotope dilution, and it can also be applied to analyze IAA biosynthesis and biosynthetic pathways using stable isotope labeling. The method will potentially advance knowledge of the role and regulation of IAA.     

Evidence for the Use of Low-Grade Weirs in Drainage Ditches to Improve Nutrient Reductions from Agriculture

Typical controlled drainage structures in drainage ditches provide drainage management strategies for isolated temporal periods. Innovative, low-grade weirs are anticipated to provide hydraulic control on an annual basis, as well as be installed at multiple sites within the drainage ditch for improved spatial biogeochemical transformations. This study provides evidence toward the capacity of low-grade weirs for nutrient reductions, when compared to the typical controlled drainage structure of a slotted riser treatment. Three ditches with weirs were compared against three ditches with slotted risers, and two control ditches for hydraulic residence time (HRT) and nutrient reductions. There were no differences in water volume or HRT between weired and riser systems. Nutrient concentrations significantly decreased from inflow to outflow in both controlled drainage strategies, but there were few statistical differences in N and P concentration reductions between controlled drainage treatments. Similarly, there were significant declines in N and P loads, but no statistical differences in median N and P outflow loads between weir (W) and riser (R) ditches for dissolved inorganic phosphate (W, 92%; R, 94%), total inorganic phosphate (W, 86%; R, 88%), nitrate-N (W, 98%; R, 96%), and ammonium (W, 67%; R, 85%) when nutrients were introduced as runoff events. These results indicate the importance of HRT in improving nutrient reductions. Low-grade weirs should operate as important drainage control structures in reducing nutrient loads to downstream receiving systems if the hydraulic residence time of the system is significantly increased with multiple weirs, as a result of ditch length and slope.     

Extending the Encounter–Norm–Crowding Generalization to Angler Evaluations of Other Social and Resource Indicators

Recreationists who encounter more people than their normative tolerance for seeing others usually feel more crowded than those encountering fewer than their norm. This research note extends this observation–norm–evaluation relationship (e.g., encounter–norm–crowding) to other evaluations and indicators. Data were from a survey of anglers on the Gulkana National Wild River in Alaska (n = 288). Respondents who encountered more people than their norm felt more crowded than those encountering fewer than their norm. When impacts from other social indicators (e.g., camping within sight or sound of other groups, fishing area competition) exceeded user norms, crowding was higher and satisfaction with overall trip quality was lower than for those experiencing less than their norms. When impacts from resource indicators (e.g., litter, impacted campsites) exceeded norms, satisfaction with both environmental quality and trip quality were lower than for those experiencing less than their norms. The encounter–norm– crowding generalization, therefore, extended to other indicators and evaluations.     

基于Landsat和MODIS数据融合的农牧区NPP模拟

天山北坡是中国重要的农牧业发展基地,利用遥感数据准确获取植被净初级生产力(Net primary productivity,NPP)的时空信息,对于合理分配农牧业草地资源具有重要意义。由于受到天气影响及卫星传感器受到时间分辨率和空间分辨率的限制,获取既具有中空间分辨率、又具有高时间分辨率的遥感数据比较困难。本文基于中空间分辨率Landsat 8 OLI数据与高时间分辨率MODIS数据,采用遥感数据时空融合STARFM算法,获取中空间分辨率和高时间分辨率序列的遥感数据,以天山北坡中段区域为实验区,结合CASA模型,对区域内植被NPP进行模拟。结果表明,2016年内8个时期,融合后的NDVI数据与对应时刻的Landsat 8 OLI NDVI数据的相关系数不小于0.759,偏差在0.006 2～0.009 4之间,均方根误差在0.074～0.135之间;利用融合数据与CASA模型协同模拟的NPP具有良好的空间细节信息,NPP模拟值与野外实测值决定系数R~2为0.860 1,表明两者具有较好的相关性。本研究为多源遥感影像融合技术与光能利用率模型协同模拟NPP提供了新的思路。     

Genetic diversity and relatedness estimates for captive barramundi (Lates calcarifer,Bloch) broodstock informs efforts to form a base population for selective breeding

Aquaculture of barramundi or Asian seabass (Lates calcarifer) is growing in both Australia and Southeast Asia and there is substantial interest to improve production efficiency through selective breeding. The establishment of a large and genetically diverse base population is a prerequisite for a sustainable and long‐term productive breeding program. Before selective breeding programs can begin for Australian barramundi it is important to assess the overall genetic diversity of current captive broodstock populations. To address this question, 407 captive barramundi broodstock from eight separate Australian broodstock populations were genotyped using 16 polymorphic microsatellite DNA markers. A Bayesian STRUCTURE analysis indicated that captive Australian broodstock are broadly divided into two genetic stocks. Multivariate analysis between broodstock individuals and pairwise F_ST between broodstock populations also supported the existence of two stocks. Comparisons with data obtained from natural stocks suggested that hatchery individuals were either sourced from the two stocks or represented an admixture between them. Genetic diversity was low within each broodstock population (allelic richness ranged from 2.67 to 3.42 and heterozygosity ranged from 0.453 to 0.537) and relatedness estimates within hatcheries were generally low (average r was equal to 0.141). We recommend sourcing captive individuals according to high levels of neutral genetic diversity and low levels of relatedness for the establishment of a base population. We also make recommendations about including genetically diverse wild individuals.