Pesticide effects on body temperature of torpid/hibernating rodents (Peromyscus leucopus and Spermophilus tridecemlineatus)

Environmental contaminants have been shown in the lab to alter thyroid hormone concentrations. Despite the role these hormones play in the physiological ecology of small mammals, no one has investigated the possible effects of thyroid-disrupting chemicals on mammalian thermal ecology and thermoregulatory ability. Because the energetic impact of such a disruption is likely to be most dramatic during times already energetically stressful, we investigated the effects of two common pesticides (atrazine and lindane) on the use of daily torpor in white-footed mice, and the use of hibernation in 13-lined ground squirrels. Fortunately, we found that these strategies for over-wintering success were not impaired

Proton and cadmium adsorption by the archaeon Thermococcus zilligii: Generalising the contrast between thermophiles and mesophiles as sorbents

Adsorption by microorganisms can play a significant role in the fate and transport of metals in natural systems. Surface complexation models (SCMs) have been applied extensively to describe metal adsorption by mesophilic bacteria, and several recent studies have extended this framework to thermophilic bacteria. We conduct acid-base titrations and batch experiments to characterise proton and Cd adsorption onto the thermophilic archaeon Thermococcus zilligii. The experimental data and the derived SCMs indicate that the archaeon displays significantly lower overall sorption site density compared to previously studied thermophilic bacteria such Anoxybacillus flavithermus, Geobacillus stearothermophilus, G. thermocatenulatus, and Thermus thermophilus. The thermophilic bacteria and archaea display lower sorption site densities than the mesophilic microorganisms that have been studied to date, which points to a general pattern of total concentration of cell wall adsorption sites per unit biomass being inversely correlated to growth temperature

Arkansas Gray Fox Fur Price-Harvest Model Revisited

Peck and Heidt (1985) proposed a linear model that demonstrated that for gray fox (Urocyon cinereoargenteus) in Arkansas; total fur harvests from 1966-1982 were highly correlated with mean pelt values. Single variable models using linear regression analysis of current season pelt values (CSPV) and previous season pelt values (PSPV) were designed to predict total fur harvests. These models demonstrated high correlations (r =0.93 and 0.89, respectively). In the past 15 years, markets for fur have undergone many perturbations within Arkansas and overseas resulting in great changes in mean pelt prices. In an attempt to evaluate the continued performance of the original model, pelt price and harvest data from 1983-1997 were tested for correlation using linear regression analysis. The results from these tests showed a high correlation. Two specific years (1983 and 1987) were affected strongly by political and economic events. A new model encompassing trapping seasons from 1966 through 1997 was evaluated. Mean pelt value remains a significant predictor of total gray fox fur harvest in Arkansas

Directions for research practice in decolonising methodologies: Contending with paradox

The complex nature of colonisation presents with the potential for paradoxes in decolonising approaches, hence, fixed conventions and methods are discouraged. In this way, decolonising methodologies concerns interrogating dominant conventions in research that have typically excluded alternative ways of knowing from academia. This raises concern about the issue of breaking conventions, when it is potentially difficult to realise that one is depending upon them. An incremental approach to the research process and subsequent knowledge generated provides opportunity to challenge the conventions that typically dictate research praxis. In addition, fostering epistemological transformation and pluralism presents a solution to problems derived from dominant cultural assumptions and practices. My aim for this article is to extend upon the literature pertaining to decolonising methodologies, with this contribution of focusing on the research process as a means to avoid paradox in the decolonial intention. Accordingly, a process imperative that focuses on how researchers do research, over the tendency to focus on outcomes, emerges as a strategy to identify and contend with paradoxes within decolonial work. A questioning convention is posited as a means for mining the assumptions and biases of the dominant culture that would otherwise ensnare ones thinking. Consequently, research may be better liberated from oppressive colonising practices that are tacit within research and academic conventions. Narratives are provided throughout for illustrative example, and to better explore the concepts named

Workplace injuries in thoroughbred racing : an analysis of insurance payments and injuries amongst jockeys in Australia from 2002 to 2010

Background: There is no comprehensive study of the costs of horse-related workplace injuries to Australian Thoroughbred racing jockeys. Objectives: To analyse the characteristics of insurance payments and horse-related workplace injuries to Australian jockeys during Thoroughbred racing or training. Methods: Insurance payments to Australian jockeys and apprentice jockeys as a result of claims for injury were reviewed. The cause and nature of injuries, and the breakdown of payments associated with claims were described. Results: The incidence of claims was 2.1/1000 race rides, with an average cost of AUD 9 million/year. Race-day incidents were associated with 39% of claims, but 52% of the total cost. The mean cost of race-day incidents (AUD 33,756) was higher than non-race day incidents (AUD 20,338). Weekly benefits and medical expenses made up the majority of costs of claims. Fractures were the most common injury (29.5%), but head injuries resulting from a fall from a horse had the highest mean cost/claim (AUD 127,127). Conclusions: Costs of workplace injuries to the Australian Thoroughbred racing industry have been greatly underestimated because the focus has historically been on incidents that occur on race-days. These findings add to the evidence base for developing strategies to reduce injuries and their associated costs

Imaging of colorectal liver metastases: New developments and pending issues

Computed tomography (CT), magnetic resonance imaging (MRI), and 18-fluorideoxyglucose positron emission tomography (18 FDG-PET) are historically the most accurate imaging techniques for diagnosing liver metastases. Recently, the combination of diffusion-weighted imaging and hepatospecific contrast media, such as gadoxetic acid in MRI, have been demonstrated to have the highest diagnostic accuracy, sensitivity, and specificity for detecting liver metastases. Various recent meta-analyses have confirmed the diagnostic superiority of this combination (diffusion-weighted imaging and gadoxetic acid-enhanced MRI), especially in terms of per lesion sensitivity, as compared with CT and18 FDG-PET, even for smaller lesions ( 641 cm). However, none of the oncological guidelines have suggested the use of MRI as a first-line technique for liver metastasis detection during the staging process of oncological patients. This review analyzes the history of the principal imaging techniques for the diagnosis of liver metastases, in particular of colorectal liver metastases, focusing on the most accurate method (diffusion-weighted imaging combined with gadoxetic acid-enhanced MRI), possible reasons for the lack of its diffusion in the guidelines, and possible future scenarios

Histopathology, vitellogenin and chemical body burden in mosquitofish (Gambusia holbrooki) sampled from six river sites receiving a gradient of stressors

There are over 40,000 chemical compounds registered for use in Australia, and only a handful are monitored in the aquatic receiving environments. Their effects on fish species in Australia are largely unknown. Mosquitofish (Gambusia holbrooki) were sampled from six river sites in Southeast Queensland identified as at risk from a range of pollutants. The sites selected were downstream of a wastewater treatment plant discharge, a landfill, two agricultural areas, and two sites in undeveloped reaches within or downstream of protected lands (national parks). Vitellogenin analysis, histopathology of liver, kidney and gonads, morphology of the gonopodium, and chemical body burden were measured to characterize fish health. Concentrations of trace organic contaminants (TrOCs) in water were analyzed by in vitro bioassays and chemical analysis. Estrogenic, anti-estrogenic, anti-androgenic, progestagenic and anti-progestagenic activities and TrOCs were detected in multiple water samples. Several active pharmaceutical ingredients (APIs), industrial compounds, pesticides and other endocrine active compounds were detected in fish carcasses at all sites, ranging from < 4–4700 ng/g wet weight, including the two undeveloped sites. While vitellogenin protein was slightly increased in fish from two of the six sites, the presence of micropollutants did not cause overt sexual endocrine disruption in mosquitofish (i.e., no abnormal gonads or gonopodia). A correlation between lipid accumulation in the liver with total body burden warrants further investigation to determine if exposure to low concentrations of TrOCs can affect fish health and increase stress on organs such as the liver and kidneys via other mechanisms, including disruption of non-sexual endocrine axes involved in lipid regulation and metabolism