Kinetics of the recovery of crystallinity in ground dolomite

The kinetics of the recovery of crystallinity, evidenced in the DSC curves of this carbonate by the presence of an exothermal peak, are studied by the analysis of isothermal and dynamic DSC traces. The correspondence between the values of the activation energy computed by the Arrhenius and Coats and Redfern plots and the slopes of the ln-ln plots shows that a three-dimensional growth of nuclei model describes the process. The low value of the activation energy allows classification of the process as a recovery of crystallinity. An increase in the activation energy with grinding time is also observed.     

Retention of carotenoids in cassava roots submitted to different processing methods

Large genetic variation in carotenoid content has been reported after screening roots from thousands of cassava genotypes. Moreover, these pigments have to withstand different processing methods before cassava is consumed. True retention of β‐carotene from cassava roots that had been boiled, oven‐dried, sun‐dried, shadow‐dried, or used for gari preparation was measured. True retention was also measured after storing for 2 or 4 weeks some of the products of these processing methods. Oven‐drying, shadow drying and boiling retained the highest levels of β‐carotene (71.9, 59.2 and 55.7%, respectively) and gari the lowest (about 34.1%). Higher retention was observed when dried roots were kept as chips rather than as flour. Storage of flour packed in plastic bags under vacuum unexpectedly resulted in higher losses than storage of flour packed in plastic bags without the application of vacuum. Losses were higher during the first 2 weeks and tended to be considerably lower during the second 2 weeks of storage. Copyright © 2006 Society of Chemical Industry     

Algorithm to compute the maximal abelian dimension of Lie algebras

In this paper, the maximal abelian dimension is computationally obtained for an arbitrary finite-dimensional Lie algebra, defined by its nonzero brackets. More concretely, we describe and implement an algorithm which computes such a dimension by running it in the symbolic computation package MAPLE. Finally, we also show a computational study related to this implementation, regarding both the computing time and the memory used.     

EURECA: European-Japanese Microcalorimeter Array

The EURECA project aims to demonstrate technological readiness of a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X, EDGE, and XEUS. The prototype instrument consists of a 5×5 pixel array of TES-based micro-calorimeters read out by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM) with digital base-band feedback. The detector array is cooled by a cryogen-free cryostat consisting of a pulse tube cooler and a two stage ADR. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.5 eV at 250 eV for read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected end 2008.      

Pregnenolone and progesterone metabolism by the testes of Bufo arenarum

Outcomes and predicting factors of mortality were studied in a consecutive series of 190 female medical patients admitted with acute illness to the Department of Medicine. Most of the patients were admitted from the Emergency Department. Twenty seven patients (14.2%) died. Seventy per cent of the patients who died, died during the first week of hospitalisation. Nearly 10 per cent of the patients who did not die, stayed in the hospital for longer than 4 weeks. At the time of home discharge, 20 patients (12.3%) had a Barthel ADL Index score less than 12, 19 patients (11.7%) had urinary incontinence, 16 patients (9.8%) had faecal incontinence, and only 103 patients (63.2%) could walk independently. The elderly patients had a significantly higher disability level at the time of home discharge than the younger patients. Independent predicting factors of mortality among this population study were "history of acute confusion", "systolic blood pressure < 100", "hematocrit < 30 per cent", "platelet < 100,000", and "a low Chula Mental Test score". Implementation of auditing and quality assurance in every acute-care hospitals is recommended.     

Pattern of ivermectin (sheep) and doramectin (cattle) residues in muscular tissue from various anatomical locations

This trial reports comparative drug residual concentrations in muscular tissue obtained from various anatomical locations after subcutaneous administration of ivermectin (IVM) to sheep and topical treatment with doramectin (DRM) to calves at recommended therapeutic dose rates. Seven muscle samples from different anatomical locations (rhomboideus, supraspinatus, semitendinosus, gluteus medius, longissimus dorsi thoracis, intercostales and diaphragma) were collected at several post-treatment sampling times. Samples were frozen at-20°C until analyzed by HPLC. The highest IVM residual concentrations in muscular tissue from the different locations were found at 15 days post-treatment in sheep. Although the highest IVM mean concentrations were measured at 15 (16.8 ± 5.17 ng g^-1) and 20 (10.5 ± 4.06 ng g^-1) days post-administration in the intercostales muscles, at 30 days post-administration, the IVM concentration in this location was similar to that measured in the rhomboideus and diaphragma muscles. DRM residual concentrations were quantified in muscular tissue from all anatomical locations after topical administration to calves. Maximum residue level was observed at 10 days post-treatment in all anatomical sites. The diaphragma muscle showed the highest DRM residue levels at 2 (22.0 ± 4.35 ng g^-1), 5 (45.2 ± 3.78 ng g^-1) and 10 (57.9 ± 9.57 ng g^-1) days post-treatment in calves. These results demonstrated that the pattern of residue depletion from muscular tissue may differ according to its anatomical locations and/or physiological role. This should be considered in implementing residue control strategies in meat safety assurance for human consumption.     

Meta-analysis of the effect of oral selenium supplementation on milk selenium concentration in cattle

Soils in many regions of the world have a low Se content. Consequently, forages and crops grown on these soils may provide inadequate dietary Se for humans and grazing animals. Selenium supplementation has been used to enhance Se status and milk Se concentration, but results conflict. Milk Se concentration appears to be a useful indicator of animal and herd Se status, and reflects the responsiveness to supplementation. A systematic review and meta-analysis were carried out to summarize all available scientific evidence for the effect of oral Se supplementation on milk Se concentration in cattle. The literature search was based on electronic and nonelectronic databases. Fixed- and random-effects models of meta-analysis were used, and a meta-regression was carried out to evaluate heterogeneity among studies. Random-effects meta-analysis was performed on 42 studies published between 1977 and 2007. Oral Se supplementation resulted in an average increase in milk Se content of 0.16 (95% confidence interval: 0.117, 0.207) μmol/L, with a significant heterogeneity among studies. Weak publication bias was evident, but it did not change the average effect. The continent where the study was performed, Se source, Se dose, and the interaction between source and dose explained 71% of the between-study variance. On average, American cows supplemented with Se yeast (e.g., 6 mg/h per day) had greater milk Se concentrations (approximately 0.37 μmol/L) 75 d after the beginning of supplementation when compared with those supplemented with inorganic forms of Se. This information provides a basis for tailoring daily animal requirements and for enhancing the Se intake of consumers of dairy products.     

Effect of freezing rate on quality parameters of freeze dried soursop fruit pulp

The effect of freezing rate on the final moisture and ascorbic acid content, water solubility, wettability and color of freeze dried soursop fruit pulp treated with maltodextrin was studied. Different size ice crystals derived from distinct freezing rates origins diversity of product specific surface area that influence both water desorption and water dissolution, but in opposite manners. After a constant drying time of 6 h the moisture content of the dried samples was in the range of 8.68–13.09% being higher for higher values of freezing rate. An inverse linear dependence between initial freezing rate and final water solubility (85.75–81.51%) of freeze dried samples was also found. Faster freezing rates also affected the wetting time (0.36–1.26 min) because they produced decreasing in pore size and simultaneously increasing in capillary tortuosity of the final micro-structure of the dried samples. Freeze-dried powders were much brighter in color compared to the maltodextrin treated pulp. Among the freeze dried samples, those prepared with higher freezing rates were lighter in color.     

Pattern of ivermectin (sheep) and doramectin (cattle) residues in muscular tissue from various anatomical locations

This trial reports comparative drug residual concentrations in muscular tissue obtained from various anatomical locations after subcutaneous administration of ivermectin (IVM) to sheep and topical treatment with doramectin (DRM) to calves at recommended therapeutic dose rates. Seven muscle samples from different anatomical locations (rhomboideus, supraspinatus, semitendinosus, gluteus medius, longissimus dorsi thoracis, intercostales and diaphragma) were collected at several post-treatment sampling times. Samples were frozen at–20°C until analyzed by HPLC. The highest IVM residual concentrations in muscular tissue from the different locations were found at 15 days post-treatment in sheep. Although the highest IVM mean concentrations were measured at 15 (16.8?±?5.17 ng g^?1) and 20 (10.5?±?4.06 ng g^?1) days post-administration in the intercostales muscles, at 30 days post-administration, the IVM concentration in this location was similar to that measured in the rhomboideus and diaphragma muscles. DRM residual concentrations were quantified in muscular tissue from all anatomical locations after topical administration to calves. Maximum residue level was observed at 10 days post-treatment in all anatomical sites. The diaphragma muscle showed the highest DRM residue levels at 2 (22.0?±?4.35 ng g^?1), 5 (45.2?±?3.78 ng g^?1) and 10 (57.9?±?9.57 ng g^?1) days post-treatment in calves. These results demonstrated that the pattern of residue depletion from muscular tissue may differ according to its anatomical locations and/or physiological role. This should be considered in implementing residue control strategies in meat safety assurance for human consumption.     

Postmortem muscle cells die through apoptosis

Several reports suggested the activation of caspases in postmortem muscle implicating the onset of a caspase-dependent cell death process after animal bleeding. It has been further well established that apoptosis and necrosis are the two major cell death pathways. The questions addressed in the present work were as follows: (a) in postmortem muscle, do cells die as in vivo? and (b) if so, by which dying process this goal is achieved? Selected hallmarks of apoptosis (phosphatidylserine externalization (PS), cell shrinkage, actin degradation) were analyzed in postmortem rat muscles and compared to usual cell behavior in apoptotic and necrotic processes. Results presented clearly demonstrate a rapid PS externalization and cell shrinkage extending during the first 24 h postexsanguination together with a progressive degradation of cytoskeletal and thin filaments of actin. It was therefore concluded that, in postmortem muscle, cells commit suicide soon after animal bleeding through apoptosis.