The Interplay Between Life History and Environmental Stochasticity: Implications for the Management of Exploited Lizard Populations

SYNOPSIS. The sustainable use of wild species by local peopleis emerging as an important conservation strategy. The premiseis the economic value of species will justify their own preservationas well as the habitats they occupy. However, the lack of naturalhistory and demographic information for the majority of speciesbeing exploited or with potential uses presents challengingproblems for implementing sustainable use programs. Each yearin Argentina and Paraguay, an average of 1.9 million tegu lizardsof the genus Tupinambis are exploited for their skins. In spiteof the importance of tegus as a resource, their biology is poorlyknown and their populations have never been managed. The lifehistory of Tupinambis, like that of other exploited lizards,is characterized by a relatively long life span, a large clutchsize, several years of growth before reproduction, and highmortality of hatchlings. Importantly, the mortality of young-of-the-yearand the proportion of females reproducing each year are bothprobably strongly influenced by interannual environmental variation.Whenthese parameters were randomized in life table projections tosimulate the effects of environmental stochasticity, the populationgrowth rate was highly sensitive to environmental fluctuations.Monte Carlo simulations of different harvest strategies showedthat estimates of population growth rates were overwhelminglyinfluenced by environmental variation and the number of yearsincluded in the growth rate estimate, even in the face of seeminglylarge changes in adult mortality that would result from populationmanagement. These results are both encouraging and cautionaryfor Tupinambis conservation. On the one hand these patternscan help explain how Tupinambis populations may have persistedin spite of high and variable harvest levels during many years,but conversely, stochastic effects make it difficult to evaluatethe effects of conservation measures. Size and sex can be determinedfrom harvested skins, and pilot studies suggest that analysesof the annual harvest can provide valuable information for evaluatinglong-term population trends.     

The Results of Parenteral Injections of Sporulated or Unsporulated Oocysts of Eimeria bovis in Calves

SYNOPSIS. Five experiments using newborn Holstein-Friesian and weaner Hereford calves were conducted to observe the effects caused by parenteral injections of oocysts of Eimeria bovis . Sporulated oocysts were given intraperitoneally (IP), subcutaneously (SC), intramuscularly (IM) and intravenously (IV). Unsporulated oocysts or merozoites were given IP or IM.
Coccidiosis developed in calves in three experiments after they were inoculated IP with sporulated oocysts. Immunity to reinfection resulted from these infections. No infections occurred at any time after SC, IM or IV inoculation with sporulated oocysts or after IP or IM inoculation with unsporulated oocysts or merozoites.
Coccidiosis failed to occur in two experiments when special precautions were used to prevent puncture of the intestines during IP inoculations. There was no detectable immunological response to any of the inoculations unless intestinal infections occurred.
In one experiment sporulated oocysts were exposed to 60,000 r irradiation by x-ray in an attempt to attenuate the oocysts. Calves became infected when given orally administered oocysts irradiated at this level.     

Mesenchymal stromal cell therapy: progress in manufacturing and assessments of potency

Mesenchymal stromal cell (MSC) therapies have been pursued for a broad spectrum of indications but mixed reports on clinical efficacy have given rise to some degree of skepticism regarding the effectiveness of this approach. However, recent reports of successful clinical outcomes and regulatory approvals for graft-versus-host disease, Crohn's disease and critical limb ischemia have prompted a shift in this perspective. With hundreds of clinical trials involving MSCs currently underway and an increasing demand for large-scale manufacturing protocols, there is a critical need to develop standards that can be applied to processing methods and to establish consensus assays for both MSC processing control and MSC product release. Reference materials and validated, uniformly applied tests for quality control of MSC products are needed. Here, we review recent developments in MSC manufacturing technologies, release testing and potency assays. We conclude that, although MSCs hold considerable promise clinically, economies of scale have yet to be achieved although numerous bioreactor technologies for scalable production of MSCs exist. Additionally, rigorous disease-specific product testing and comprehensive understanding of mechanisms of action, which are linked to relevant process and product release potency assays, will be required to ensure that these therapies continue to be successful.     

A proposed framework for determining the environmental impact of replacing agricultural grassland with Miscanthus in Ireland

Energy crops offer an opportunity to substantially increase bioenergy resources which can replace rapidly depleting fossil fuel reserves and mitigate the effect of climate change. Energy crops are typically established within traditional agricultural systems such as tillage land or grassland. Associated land use conversion has environmental implications. The aim of this paper is to propose a framework to examine how such environmental implications can be assessed, based on (a) a Strategic Environmental Assessment (SEA) approach which considers potential impacts at different stages of a plan across a wide range of environmental receptors and (b) a literature review. The example we used was that of Miscanthus replacing grassland farming. This scenario is particularly relevant to Ireland, where over 90% of the agricultural land is permanent pasture, but is also applicable to grassland conversion throughout Europe and the United States. Two consecutive phases of land‐use change were identified for assessment, each with a distinct set of environmental impacts. The first was a transition phase, lasting from initial livestock clearance and grassland ploughing until the Miscanthus crop became established (2–3 years). The second phase was the mature crop phase, lasting up to 25 years. Miscanthus cultivation was more likely to impact negatively on the environment during the transition phase than the mature phase, primarily due to abrupt disturbance and the time required for a new equilibrium to establish. However, a literature review of the impact on the environmental receptors revealed that replacing Irish agricultural grassland with Miscanthus had the potential to improve biodiversity, water, air and soil quality, and climatic factors once the crop became established and reached maturity. In order to confirm these findings an appropriate monitoring programme involving objectives and indicators associated with each environmental receptor would need to be developed.