The postnatal development of the mucosal immune system and mucosal tolerance in domestic animals

The mucosal immune system is exposed to a range of antigens associated with pathogens, to which it must mount active immune responses. However, it is also exposed to a large number of harmless antigens associated with food and with commensal microbial flora, to which expression of active, inflammatory immune responses to these antigens is undesirable. The mucosal immune system must contain machinery capable of evaluating the antigens to which it is exposed and mounting appropriate effector or regulatory responses. Since the immune system is likely to have evolved initially in mucosal tissues, the requirement to prevent damaging allergic responses must be at least as old as the adaptive immune system, and studies of the mechanisms should include a range of non-mammalian species. Despite the importance for rational design of vaccines and for control of allergic reactions, the mechanisms involved are still largely unclear. It is not clear that the classical experimental protocol of "oral tolerance" is, in fact, measuring a biologically important phenomenon, nor is it clear whether tolerance is regulated in the evolutionarily recent organised lymphoid tissue (the lymph nodes) or the more ancient, diffuse architecture in the intestine. The capacity of the immune system to discriminate between "dangerous" and "harmless" antigens appears to develop with age and exposure to microbial flora. Thus, the ability of an individual or a group of animals to correctly regulate mucosal immune responses will depend on age, genetics and on their microbial environment and history. Attempts to manipulate the mucosal immune system towards active immune responses by oral vaccines, or towards oral tolerance, are likely to be confounded by environmentally-induced variability between individuals and between groups of animals.     

Nonsurgical repair of an umbilical hernia in two Asian elephant calves (Elephas maximus)

Umbilical hernias were diagnosed in two captive-born, female Asian elephant (Elephas maximus) calves several weeks after birth. Daily manual reduction of the hernias for 5 wk in the first case and for 5 mo in the second resulted in complete closure of the defects. Nonsurgical repair of uncomplicated, fully reducible umbilical hernias in Asian elephants can be an alternative to surgery.     

Community food security: Salience and participation at community level

Community food security (CFS) is an incipient movement based on the re-localization of many food system activities in response to values concerning the social, health, economic, and environmental consequences of the globalizing food system. This study examines the salience of these values based on the action agendas and accomplishments emerging from community planning events in six rural counties of New York, and the nature and type of participation and local support. The study finds a high level of agreement between CFS values as articulated by national leaders in this incipient movement and the action agendas. Further evidence of the salience of these themes is seen in the levels and types of activities and accomplishments taking place 8--12 months after the planning events. However, these follow-through activities appear to have been impeded by a variety of government regulations, uneven levels of support from community organizations and agencies, and a policy environment of fiscal austerity, narrow outcome-oriented accountability, and allocation of agency staff toward special-purpose grants and contracts. Many of these constraints are likely to exist in other communities and are beyond the scope of what community volunteers and practitioners can be expected to address on their own.     

Comparative life cycle environmental impacts of three beef production strategies in the Upper Midwestern United States

We used ISO-compliant life cycle assessment (LCA) to compare the cumulative energy use, ecological footprint, greenhouse gas emissions and eutrophying emissions associated with models of three beef production strategies as currently practiced in the Upper Midwestern United States. Specifically we examined systems where calves were either: weaned directly to feedlots; weaned to out-of-state wheat pastures (backgrounded) then finished in feedlots; or finished wholly on managed pasture and hay. Impacts per live-weight kg of beef produced were highest for pasture-finished beef for all impact categories and lowest for feedlot-finished beef, assuming equilibrium conditions in soil organic carbon fluxes across systems. A sensitivity analysis indicated the possibility of substantial reductions in net greenhouse gas emissions for pasture systems under conditions of positive soil organic carbon sequestration potential. Forage utilization rates were also found to have a modest influence on impact levels in pasture-based beef production. Three measures of resource use efficiency were applied and indicated that beef production, whether feedlot or pasture-based, generates lower edible resource returns on material/energy investment relative to other food production strategies.     

Automated detection and tracking of marine mammals: A novel sonar tool for monitoring effects of marine industry

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Spatial modelling of photosynthesis for a boreal mixedwood forest by integrating micrometeorological,lidar and hyperspectral remote sensing data

The adaptation of a national/continental-scale model of carbon uptake to the local-scale using highly detailed airborne discrete lidar and hyperspectral data was investigated at a boreal forest mixedwood site in northern Ontario. Spatially explicit maps of canopy chlorophyll concentration and the fraction of photosynthetically active radiation absorbed by the canopy (FPAR) under direct and diffuse radiative conditions were developed for five time periods in 2004 (i.e., winter (January 1–May 31), leaf-out (June 1–20), summer (June 21–July 31 and August 1–31) and senescence (September 1–30)). The maps were used in conjunction with meteorological measurements, such as incident total and diffuse PAR, global solar radiation, and air temperature, taken on a flux tower which is located at the center of the study.Distinct spatial patterns in FPAR, a result of changes in canopy chlorophyll concentration, are increasingly evident throughout the season because of the variation in species groupings within the 1-km radius surrounding the flux tower. In general, the model shows a good correlation to flux-tower-measured gross ecosystem productivity (GEP) (r² = 0.70 for 10-day averages throughout the year), with the largest deviations occurring in June–July. Species-level data shows the influence of a large homogenous patch of black spruce on the tower measured GEP and demonstrates the contribution of white birch, by far the most dominant species, to the total GEP for the area.     

Clinical Update on Testing Modalities for Encephalitozoon cuniculi in Clinically Sick Rabbits

This article describes the clinical presentation of rabbit patients infected with Encephalitozoon cuniculi that present to veterinary hospitals. The difficulty in obtaining a definitive diagnosis with this disease, even in animals with severe clinical signs, is frustrating to veterinarians and owners alike. A detailed review of current diagnostic testing methodologies and recent advances should help with the interpretation of E. cuniculi test results to communicate and inform owners on treatment and prevention of this devastating disease.     

Evaluation of genetic diversity among some Iranian wild asparagus populations using morphological characteristics and RAPD markers

An evaluation of genetic diversity in 39 wild asparagus populations was carried out using morphological and RAPD markers. A combination of morphological traits and random RAPD primers was used to examine the level of genetic variation and polymorphisms among the populations. A factor analysis using Ward's method on mean values of morphological characteristics indicated seven main factors resulting in four groups. Analysis of polymorphic bands using Jaccard's similarity coefficient indicated that genetic similarity ranged between 0.71 and 0.29. At a similarity level of 0.64, the populations were divided in three sub-clusters, containing 34, four and one populations, respectively. Significant regression associations were found between 21 morphological characteristics and 18 RAPD markers, revealing some informative markers associated with some traits. The highest R² was related to 18 RAPD markers associated with gender (53.5%) that among them BA-04₂₀₀₀ had a maximum R². The results showed that Iranian wild asparagus with its high levels of genetic variation could be considered as a valuable gene pool for future asparagus breeding programs. Furthermore, it could be inferred that morphological characteristics and RAPD markers are suitable tools to discriminate asparagus populations for the evaluation of genetic diversity.