Using LC-MSMS to assess glutathione levels in South African white grape juices and wines made with different levels of oxygen

The effect of oxygen on the levels of glutathione, an important antioxidant, in must and wine was studied using a novel LC-MSMS method for the analysis of reduced and oxidized glutathione. This study found that the storage of grape juice at high SO2 and ascorbic acid levels at -20 degrees C did not lead to a decrease in reduced glutathione levels. The effect of varying the oxygen levels in South African white grape juices, which included a reductive treatment (less than 0.3 mg/L dissolved O2 added), a control treatment (between 1.0 and 1.5 mg/L dissolved O2 added), and an oxidative treatment (3.5-4 mg/ L dissolved O2 added, without SO2) on reduced glutathione levels in the juice and resulting wine was also investigated. A custom build press was used to press whole bunches of two different Sauvignon Blanc and Colombard grapes. Alcoholic fermentation and oxygen additions to the must led to lower reduced glutathione levels in the wine. Reduced glutathione levels were only significantly higher in the wine made from reductive juice that had the highest initial reduced glutathione levels in the grapes.     

Quantification of melamine absorption, distribution to tissues, and excretion by sheep

Eight D?hne Merino rams were used to quantify apparent absorption, distribution to tissues, and excretion of dietary melamine in sheep. Two batches of concentrate pellets were made; one (CON) contained corn gluten meal with no detectable melamine and the other (MEL) contained corn gluten meal that was previously found to be highly contaminated with melamine at 15,117 mg/kg. The MEL pellets contained 1,149 mg/kg of melamine. During a 10-d adaptation period, all the animals received a forage-based diet supplemented with 600 g/d of the CON pellets. This was followed by an 8-d collection period during which 6 of the animals received MEL pellets and 2 received CON pellets. Melamine intake of sheep that received MEL pellets was 0.69 g/d. Blood samples were taken before first ingestion of MEL pellets on d 1 and again on d 3, 6, and 8 of the collection period for melamine and serum creatinine analyses. Feces and urine were collected quantitatively over the 8 d for proximate and melamine analyses. All the animals were slaughtered at the end of the trial, and samples of the LM, liver, kidneys, and abdominal fat were taken for melamine analysis. Data of the 2 sheep that received CON pellets for the duration of the trial confirmed that no melamine was detected in any of the samples, and no statistical analyses were performed on these data. The apparent digestibility or efficiency of absorption of ingested melamine was 76.7%. Melamine was detected in the urine, blood, muscle (LM), and fat tissue of all the sheep that received MEL pellets. Serum melamine concentrations reached 5.4 mg/kg on d 8 of the collection period, and the meat (LM) contained 9.6 mg/kg of melamine. Calculations on the partitioning of ingested melamine suggested that urine is the major excretion route accounting for 53.2%, whereas feces accounted for 23.3% of ingested melamine. Approximately 3.5% of the ingested melamine was detected in muscle. It was concluded that ingested melamine is highly absorbable from the small intestine and that a pathway exists for the distribution of dietary melamine to meat.     

COMPUTED TOMOGRAPHIC AND RADIOGRAPHIC CHARACTERISTICS OF AORTIC LESIONS IN 42 DOGS WITH SPIROCERCOSIS

Spirocerca lupi is a common cause of vomiting, regurgitation, and sudden death in dogs that live in tropical or subtropical regions. Sudden death due to aortic rupture may occur with no preceding clinical signs. The purpose of this prospective study was to compare radiographic and computed tomographic (CT) characteristics of aortic lesions in a cohort of 42 dogs with endoscopically confirmed spirocercosis. Dorsoventral and right lateral recumbent thoracic radiographic findings were compared with pre‐ and postcontrast thoracic CT findings. Aortic mineralization was detected using CT in 18/42 dogs (43%). Three dogs had faint diffuse aortic wall mineralization. Using CT as the reference standard, radiographs had a sensitivity and specificity of 6% and 96%, respectively, for detecting aortic mineralization. A total of 20 aortic aneurysms were detected using CT in 15/42 dogs (36%). Using CT as the reference standard, radiographs had a sensitivity and specificity of 86% and 56%, respectively, for detecting aortic aneurysms. Respiratory motion, aortic displacement by esophageal masses and Spirocerca nodules adjacent to the aorta mimicked aneurysm formation on radiographs. Aortic thrombi were seen in two dogs in postcontrast CT images. Findings from this study indicated that aortic mineralization and aneurysm formation are common in dogs with spirocercosis. Findings also supported the use of pre‐ and postcontrast CT as effective methods for detecting and characterizing these lesions.     

Dust and Bioaerosols At a Biosolids Composting Facility

Workers at composting facilities are exposed to organic dusts and bioaerosols. The bioaerosols of major concern are Aspergillus fumigatus (A. fumigatus) and endotoxin. An evaluation of employee exposure to dust, endotoxin, and A. fumigatus spores was conducted in a totally enclosed biosolids composting facility that composts biosolids with sawdust. Total and respirable dust, endotoxin, and A. fumigatus were measured during several of the major composting activities. Periodic total dust levels exceeded the OSHA PEL standard for nonspecific dust. Endotoxin levels as high as 640 ng/m³ were recorded when piles were torn down. During mixing of biosolids and sawdust, A. fumigatus counts exceeded 6,000 CFU/m³. Based on the data obtained, several mitigation measures were implemented. Evaluation of the facility after the changes were made found that levels of total dust, endotoxin, and A. fumigatus were reduced by 90 percent.     

Using climate variables to predict small mammal occurrence in hot, dry environments

Many species are considered to be threatened by the direct and synergistic effects of increased temperatures and less reliable rainfall caused by anthropogenic climate change. The climate of arid Australia is naturally defined by high temperatures and highly variable rainfall. In these environments the survival of small mammals is facilitated by a range of physiological, morphological and behavioural adaptive traits (e.g. insectivorous diets, torpor, nocturnal activity and sheltering in burrows). Features within the landscape associated with these traits may have a proximal influence on species occurrence and be critical for predicting the distribution of arid species. Here we explored the contribution of coarse- and fine-scale environmental variables, sampled from 150 to 10,000 m from known species records, to the development of more robust species distribution models. The inclusion of environmental variables representing topography, soil and vegetation better modelled occurrence for all five small mammal species (up to 55.2 % DE increase over climate-only models) and increased discrimination of species occurrence in an out-of-sample cross-validation for Antechinomys laniger, Dasyuroides byrnei and Notomys cervinus (e.g. increase in area-under-the curve by 0.4). For these species, model performance (% DE) increased with the resolution of environmental data used, reflecting a coarse-scale relationship with distance to watercourse (e.g. at 1,000 m), but masking a fine-scale relationship with rainfall during winter (at 150 m). The inclusion of a fine-scale variable shrub cover under 0.5 m (SD) improved the representation of S. macroura occurrence. These results show improved representation of habitats and resources using course- and fine-scale variables, which may be vital to model the occurrence of some species and their refuge habitats, but as static variables may limit accurate predictions of the effect of climate change on species range dynamics.