Dityrosine, 3,4-dihydroxyphenylalanine (DOPA), and radical formation from tyrosine residues on milk proteins with globular and flexible structures as a result of riboflavin-mediated photo-oxidation

Riboflavin-mediated photo-oxidative damage to protein Tyr residues has been examined to determine whether protein structure influences competing protein oxidation pathways in single proteins and protein mixtures. EPR studies resulted in the detection of Tyr-derived o-semiquione radicals, with this species suggested to arise from oxidation of 3,4-dihydroxyphenylalanine (DOPA). The yield of this radical was lower in samples containing β-casein than in samples containing only globular proteins. Consistent with this observation, the yield of DOPA detected on β-casein was lower than that on two globular proteins, BSA and β-lactoglobulin. In contrast, samples with β-casein gave higher yields of dityrosine than samples containing BSA and β-lactoglobulin. These results indicate that the flexible structure of β-casein favors radical-radical termination of tyrosyl radicals to give dityrosine, whereas the less flexible structure of globular proteins decreases the propensity for tyrosyl radicals to dimerize, with this resulting in higher yields of DOPA and its secondary radical.     

Contiguity of landscape features pose barriers to gene flow among American marten (<Emphasis Type="Italic">Martes americana</Emphasis>) genetic clusters in the Upper Peninsula of Michigan

Context

Barriers to dispersal influence the ability of individuals to expand into new areas and can ultimately define success of reintroduction programs. American marten (Martes americana) were reintroduced to the Upper Peninsula of Michigan, USA, from multiple, genetically differentiated source populations from 1955 to 1992. Previous research found multiple genetic clusters near release sites with little admixing, suggesting barriers to dispersal exist.

Objectives

We sought to identify whether the contact zones between genetic clusters coincided with landscape features hypothesized to influence M. americana dispersal. We also investigated whether the degree of landscape contiguity within each genetic cluster differed among clusters.

Methods

We mapped cluster boundaries in M. americana genetic assignment probabilities and used correlation length as a measure of landscape contiguity between genetic clusters. We then evaluated the effects of land cover and roads on spatial genetic structure using a spatial autoregressive model.

Results

We found that gene flow was facilitated by contiguous coniferous forest and low incidence of roads. However, the strength of those relationships varied by genetic cluster. Contact zones among some genetic clusters spatially coincided with areas of high road and low conifer contiguity, compared to within-clusters.

Conclusions

In contrast to landscape genetic analyses focused on identifying barriers to gene flow, we incorporated methods that are relatively novel in landscape genetics to quantify how landscape contiguity influences spatial genetic structure. Using this method we were able to identify landscape barriers to dispersal at the genetic cluster boundaries for a reintroduced species distributed continuously across the landscape.

     

Suspected primary pure red cell aplasia in a 4-month-old intact male mixed breed Bernese mountain dog

A 4-month-old, 31-kg intact male mixed-breed Bernese mountain dog was presented for evaluation of severe non-regenerative anemia after several days of lethargy, inappetence and pale mucous membranes. Bone marrow evaluation and complete response to immunosuppressive therapy were suggestive of primary pure red cell aplasia (PRCA). Primary PRCA is a rare immune-mediated non-regenerative anemia that is overrepresented in middle-aged to older spayed female dogs and has not previously been described in an intact male puppy.     

Supermarket power, own-labels, and manufacturer counterstrategies: international relations of cooperation and competition in the fruit canning industry

Growing supermarket dominance and the expansion of own-label market share in Australia has put considerable pressure on agri-food manufacturers, and the recent movement of a number of manufacturing operations off-shore has attracted widespread attention. This paper examines the pursuit of an international manufacturing base by SPC Ardmona, one of Australia’s major fruit and vegetable processors, with a focus on strategic alliances formed with Siam Foods in Thailand and Rhodes Food Group in South Africa/Swaziland. Strategic horizontal alliances have become increasingly important for manufacturers seeking to counter retailer dominance, yet have received little attention in the agri-food literature. The two alliances examined in this paper illustrate the profound importance of prevailing societal and institutional environments in which production networks ‘touch-down’, and their influence on firm-level dynamics of trust, motivation, corporate values, and strategic objectives. Horizontal alliances can offer a promising alternative to cut-throat competition and a ‘race- to-the-bottom’ between agri-food manufacturers. However, with own-label sourcing strategies deepening competition between geographically-disparate manufacturers, identifying compatible alliance partners is likely to become an increasingly greater challenge.     

Prevention of Leptospira interogans serovar pomona infection in cattle

A commercial hardjo-pomona vaccine which has previously been shown to be effective against hardjo infection was tested against pomona. Following challenge all 11 six-month-old non-vaccinated calves seroconverted and pomona was isolated from blood or urine on at least one occasion from nine of them. Pomona was isolated once only, on the third day after challenge, from the blood of one of 11 vaccinated calves.     

Arctic seabirds transport marine-derived contaminants

Long-range atmospheric transport of pollutants is generally assumed to be the main vector for arctic contamination, because local pollution sources are rare. We show that arctic seabirds, which occupy high trophic levels in marine food webs, are the dominant vectors for the transport of marine-derived contaminants to coastal ponds. The sediments of ponds most affected by seabirds had 60 times higher DDT, 25 times higher mercury, and 10 times higher hexachlorobenzene concentrations than nearby control sites. Bird guano greatly stimulates biological productivity in these extreme environments but also serves as a major source of industrial and agricultural pollutants in these remote ecosystems.     

Bilateral laryngeal paralysis in a dog secondary to laryngeal osseous metaplasia

A 7-year-old spayed female Lurcher was evaluated for a chronic history of increased upper respiratory noise. Advanced imaging including digital radiography and pre- and post-contrast computed tomography (CT) scan confirmed the presence of an ill-defined soft tissue mineralized mass of the ventral larynx. Histopathology demonstrated pleocellular myositis and fasciitis with osseous metaplasia.     

Case clusters of leproid granulomas in foxhounds in New Zealand and Australia

Background – Canine leproid granuloma (CLG) characteristically presents as single to multiple circumscribed dermal to subcutaneous nodules in haired skin. An unidentified mycobacterium is considered be the aetiological agent of this entity. Animals – Several cases of canine leproid granulomas occurred in dogs in New Zealand during 2010 and 2011. Cases appeared in clusters, affecting multiple closely related foxhounds domiciled in the same kennels. All affected hounds recovered after topical and/or systemic antimicrobial therapy. Two similar outbreaks that occurred in foxhounds near Melbourne, Australia are also reported. Methods – Cases were investigated using cytological, histological, microbiological and several molecular techniques. An environmental epidemiological study was also performed. Results – A diagnosis of CLG was established in 11 dogs. Molecular identification of the causative agent confirmed that it was a mycobacterial species with 100% sequence homology within the amplified regions of the 16S rRNA gene and internal transcribed spacer (ITS1) with that found in association with similar infections from the USA, Brazil and Australia. Conclusion and clinical importance – This report details the first occurrence of multiple cases of CLG occurring in in‐contact dogs and the first proven case of CLG in dogs in New Zealand.     

Fine temporal resolution satellite sensors with global coverage: an opportunity for landscape ecologists

Landscape Ecology - Open data policies and accessible computation platforms allow efficient extraction of information from remote sensing data for landscape research. Landscape ecology is strongly...     

Spatial prediction on a river network

This article develops methods for spatially predicting daily change of dissolved oxygen (Dochange) at both sampled locations (134 freshwater sites in 2002 and 2003) and other locations of interest throughout a river network in South East Queensland, Australia. In order to deal with the relative sparseness of the monitoring locations in comparison to the number of locations where one might want to make predictions, we make a classification of the river and stream locations. We then implement optimal spatial prediction (ordinary and constrained kriging) from geostatistics. Because of their directed-tree structure, rivers and streams offer special challenges. A complete approach to spatial prediction on a river network is given, with special attention paid to environmental exceedances. The methodology is used to produce a map of Dochange predictions for 2003. Dochange is one of the variables measured as part of the Ecosystem Health Monitoring Program conducted within the Moreton Bay Waterways and Catchments Partnership.