Extraction of β‐Glucan from Oat Bran in Laboratory Scale

Effects of various enzymes and extraction conditions on yield and molecular weight of β‐glucans extracted from two batches of commercial oat bran produced in Sweden are reported. Hot‐water extraction with a thermostable α‐amylase resulted in an extraction yield of ≈76% of the β‐glucans, while the high peak molecular weight was maintained (1.6 × 10⁶). A subsequent protein hydrolysis significantly reduced the peak molecular weight of β‐glucans (by pancreatin to 908 × 10³ and by papain to 56 × 10³). These results suggest that the protein hydrolyzing enzymes may not be pure enough for purifying β‐glucans. The isolation scheme consisted of removal of lipids with ethanol extraction, enzymatic digestion of starch with α‐amylase, enzymatic digestion of protein using protease, centrifugation to remove insoluble material, removal of low molecular weight components using dialysis, precipitation of β‐glucans with ethanol, and air‐drying.     

Processes affecting genetic structure and conservation: a case study of wild and cultivated <Emphasis Type="Italic">Brassica rapa</Emphasis>

When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.     

Oxidative stress markers in canine atopic dermatitis

There are no data in the veterinary literature relating to oxidative stress in canine atopic dermatitis (CAD). The study aimed to determine levels of oxidative stress markers, plasma malondialdehyde (MDA), total antioxidant capacity (TAC), whole blood glutathione peroxidase (GPX) and erythrocyte superoxide dismutase (SOD), in 15 CAD patients and 17 healthy dogs. A correlation between CADESI (Canine Atopic Dermatitis Extent and Severity Index) score and MDA was also determined. Significantly higher plasma MDA levels were found in patients than in healthy dogs. The significant, highly positive correlation determined between CADESI score and MDA in the patient group indicates an association between the severity of CAD and the extent of oxidative damage to membrane lipids. There were no significant differences in TAC, GPX and SOD between patients and healthy dogs. Our findings suggest that oxidative stress with increased lipid peroxidation could be involved in the pathogenesis of atopic dermatitis in dogs.     

Formation and availability of methylmercury in mercury-contaminated sediment: effects of activated carbon and biochar amendments

Journal of Soils and Sediments - As the formation of toxic and bioaccumulative methylmercury (MeHg) in Hg-contaminated sediments is of great concern worldwide, suitable remediation options are...     

Interaction between Notch and Hif-alpha in development and survival of Drosophila blood cells

A blood cell type termed crystal cell in Drosophila functions in clotting and wound healing and requires Notch for specification and maintenance. We report that crystal cells express elevated levels of Sima protein orthologous to mammalian hypoxia-inducible factor-α (Hif-α) even under conditions of normal oxygen availability. In these platelet-like crystal cells, Sima activates full-length Notch receptor signaling via a noncanonical, ligand-independent mechanism that promotes hemocyte survival during both normal hematopoietic development and hypoxic stress. This interaction initiates in early endosomes, is independent of Hif-β (Τangο in Drosophila), and does not activate hypoxia response targets. Studies in vertebrate myeloid cells have shown a similar up-regulation of Hif-α protein in well-oxygenated environments. This study provides a mechanistic paradigm for Hif-α/Notch interaction that may be conserved in mammals.     

Ancient biomolecules from deep ice cores reveal a forested southern Greenland

It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.