Role of sorption and degradation in the herbicidal function of isoxaflutole

BACKGROUND: The fate of isoxaflutole (IFT) in soil is closely related to soil sorption. Sorption and transformation of IFT were investigated in laboratory incubations with four soils, and these results were used to interpret greenhouse studies using IFT to control several weed species. RESULTS: Degradation proceeded by previously observed pathways to form diketonitrile (DKN) and benzoic acid (BA) derivatives, as well as traces of unidentified products. Over the course of the incubation, DKN was the dominant active form of the herbicide present in the experimental system, and was thus critical to the soil activity of the herbicide for weed control. CONCLUSION: Control of most weed species appeared to be a function of both sorption and biodegradation of DKN, with greatest weed control being observed in soils in which a significant portion of the DKN that was formed persisted and remained bioavailable over the course of the incubation. Copyright © 2009 Society of Chemical Industry     

Potential Use of Ultrafiltration for Groundwater Remediation and Aqueous Speciation of 60Co and 137Cs from A Contaminated Area

The potential for colloid-facilitated migration in contaminated sites is well known, and remediation techniques such as ultrafiltration are often considered for contaminant removal. Although this approach could be successful, the stability of the contaminant species in groundwater and the removal efficiency need to be investigated to ensure proper decontamination of moving aquifers. In our study, we have sampled contaminated groundwater near a former radioactive liquid disposal area at Chalk River, Ontario, Canada. Samples were taken in 2002 and 2004 to determine the behaviour of radiocontaminants by size fractionation using ultrafiltration, with emphasis on ⁶⁰Co and ¹³⁷Cs. The contaminant concentrations varied significantly for both contaminants in the two samples (34.5 and 25.5 Bq/l for ⁶⁰Co, 25.5 and 97.2 Bq/l for ¹³⁷Cs). On the other hand, the size fractionation (5,000 Da^a nominal cut-off) remained consistent between the 2002 and 2004 samples, as most of the ⁶⁰Co (72%–83%) remained in the filtrate, while almost all of the ¹³⁷Cs (>98%) was retained along with the colloidal-sized material. Release of ⁶⁰Co and ¹³⁷Cs from the colloidal material yielded desorption coefficients (K _D-des) of 7.8 × 10⁵ and 1.7 × 10⁸ ml/g for ⁶⁰Co and ¹³⁷Cs, respectively.     

Representation of animal distributions in space: how geostatistical estimates impact simulation modeling of foot-and-mouth disease spread

Modeling potential disease spread in wildlife populations is important for predicting, responding to and recovering from a foreign animal disease incursion. To make spatial epidemic predictions, the target animal species of interest must first be represented in space. We conducted a series of simulation experiments to determine how estimates of the spatial distribution of white-tailed deer impact the predicted magnitude and distribution of foot-and-mouth disease (FMD) outbreaks. Outbreaks were simulated using a susceptible-infected-recovered geographic automata model. The study region was a 9-county area (24 000 km(2)) of southern Texas. Methods used for creating deer distributions included dasymetric mapping, kriging and remotely sensed image analysis. The magnitudes and distributions of the predicted outbreaks were evaluated by comparing the median number of deer infected and median area affected (km(2)), respectively. The methods were further evaluated for similar predictive power by comparing the model predicted outputs with unweighted pair group method with arithmetic mean (UPGMA) clustering. There were significant differences in the estimated number of deer in the study region, based on the geostatistical estimation procedure used (range: 385 939-768 493). There were also substantial differences in the predicted magnitude of the FMD outbreaks (range: 1 563-8 896) and land area affected (range: 56-447 km(2)) for the different estimated animal distributions. UPGMA clustering indicated there were two main groups of distributions, and one outlier. We recommend that one distribution from each of these two groups be used to model the range of possible outbreaks. Methods included in cluster 1 (such as county-level disaggregation) could be used in conjunction with any of the methods in cluster 2, which included kriging, NDVI split by ecoregion, or disaggregation at the regional level, to represent the variability in the model predicted outbreak distributions. How animal populations are represented needs to be considered in all spatial disease spread models.     

Acceptability of multiple micronutrient supplements by pregnant and lactating women in Mali

BACKGROUND: In Mali, an estimated 73% of pregnant women are anaemic largely due to iron deficiency. National policy recommends women to take iron and folic acid supplements daily from first prenatal contact until 3 months postpartum. However, many pregnant women in Mali could benefit from multiple micronutrient supplements. OBJECTIVE: To assess pregnant women's acceptability of and adherence to a daily multiple micronutrient supplementation scheme compared with the current daily iron and folic acid supplementation scheme. DESIGN: Seventy pregnant women were allocated to either the daily multiple micronutrient or daily iron and folic acid supplementation scheme. Women started receiving supplements at the end of the first trimester of pregnancy until delivery and throughout the first 3 months postpartum. RESULTS: No significant differences were observed between comparison groups with respect to women's perceptions about supplement size, colour, taste or flavour. Adherence to the multiple micronutrient supplementation scheme was better (257.5+/-20.9 tablets; average adherence 95.4%) than that to the iron and folic acid supplementation scheme (238.5+/-32.7 tablets; average adherence 92.2%; P=0.008) although both were very good, as were women's perceptions about the benefits of micronutrient supplements to their health and that of their newborns. CONCLUSION: Malian women adhere to prenatal/postpartum micronutrient supplementation - no matter what supplement is chosen - when access to supplements is guaranteed and when they are provided with minimum, consistent and easily understandable information and counselling, indicating that these are key elements to ensure effective programmes. These findings, together with those of the global research agenda on the efficacy of multiple micronutrient supplements for pregnant women, will inform policy development in Mali for the effective control of iron deficiency and iron-deficiency anaemia in pregnant women.     

Funduscopic findings following cataract extraction by means of phacoemulsification in diabetic dogs: 52 cases (1993-2003)

OBJECTIVE: To determine prevalence of retinal hemorrhages and microaneurysms in dogs with diabetes mellitus following cataract extraction by means of phacoemulsification and identify potential risk factors. DESIGN: Retrospective study. PROCEDURE: Medical records of dogs undergoing phacoemulsification between 1993 and 2003 were reviewed, and information was recorded on signalment, history, physical examination findings, ophthalmic examination findings, results of laboratory testing, electroretinographic findings, and surgical findings. Glycemic control was classified as poor, intermediate, or good on the basis of baseline blood glucose concentration, perioperative body weight loss, daily insulin dosage, and presence of glucosuria and ketonuria. Data from diabetic and nondiabetic dogs were analyzed to determine prevalence and risk factors for development of retinal hemorrhages or microaneurysms following phacoemulsification. RESULTS: 11 of the 52 (21%) dogs with diabetes mellitus developed ophthalmoscopic signs of retinal hemorrhages or microaneurysms, compared with 1 of the 174 (0.6%) nondiabetic dogs. Median time from onset of diabetes mellitus to diagnosis of retinopathy was 1.4 years (range, 0.5 to 3.2 years). No risk factors for development of retinopathy were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that retinal hemorrhages and microaneurysms may be more common and develop earlier in diabetic dogs than previously reported. This may affect treatment, as diabetic dogs survive longer with improved glycemic control.     

Evaluation of environmental fecal culture for Mycobacterium avium subspecies paratuberculosis detection in dairy herds and association with apparent within-herd prevalence

This study evaluated test characteristics of environmental culture (EC) for the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in 32 herds over a 2-year period. Individual fecal samples were collected every 6 mo and environmental samples every 3 mo. Individual fecal culture was performed on samples from positive pools. Samples were cultured in broth, with confirmatory polymerase chain reaction performed on positive fecal samples. Repeated measures were accounted for using GEE logistic models. Relative to a MAP herd-status based on all pooled fecal culture results collected during the study, sensitivity of a set of 6 EC-samples collected from prescribed locations within the herd environment (EC-6) was 71% [95% confidence interval (CI): 49% to 86%] and specificity was 99% (95% CI: 95% to 100%). Sensitivity of EC increased as apparent within-herd fecal culture prevalence (aWHP) increased. The estimated aWHP increased as the proportion of positive EC-samples within an EC-6 set increased. Environmental culture is an acceptable tool for herd diagnosis of MAP in low-prevalence herds.     

Protection from cardiac arrhythmia through ryanodine receptor-stabilizing protein calstabin2

Ventricular arrhythmias can cause sudden cardiac death (SCD) in patients with normal hearts and in those with underlying disease such as heart failure. In animals with heart failure and in patients with inherited forms of exercise-induced SCD, depletion of the channel-stabilizing protein calstabin2 (FKBP12.6) from the ryanodine receptor-calcium release channel (RyR2) complex causes an intracellular Ca2+ leak that can trigger fatal cardiac arrhythmias. A derivative of 1,4-benzothiazepine (JTV519) increased the affinity of calstabin2 for RyR2, which stabilized the closed state of RyR2 and prevented the Ca2+ leak that triggers arrhythmias. Thus, enhancing the binding of calstabin2 to RyR2 may be a therapeutic strategy for common ventricular arrhythmias.     

A Technical Efficiency Analysis of Hawaii's Aquaculture Industry

This study examines the technical efficiency (TE) of aquaculture farms in Hawaii. Policy makers and industry participants interested in assessing the economic outlook of aquaculture production not only have to assess measures of profitability and financial health, but also measures of production efficiency. We estimate the TE of the state's aquafarms with a data envelopment analysis (DEA) model. Using data from the US Census of Agriculture, we examine TE measures of the population of Hawaii's aquafarms across different types of farms and over time. The results show that only 12% of the farms in 2007 may be classified as efficient, with a steady decline in efficiency over time. We find TE was related to the size of farm, full‐time farms were significantly more efficient than part‐time farms and that the average excess real inputs for land and labor have slightly fallen over time. The sub‐sector analysis revealed a strong variation of TE across different type of farms. With few farms operating on the frontier, the findings of this study suggest that the majority of the farms could improve their TE.