Transmission of Porcine Reproductive and Respiratory Syndrome Virus by Semen is Dose Dependent

Procine reproductive and respiratory syndrome virus (PRRSV) is transmitted through semen via natural mating or atrificial insemination. However, the minimal infective dose of PRRSV required to effect transmission through semen is not known. In this study, we induced estrus in PRRSV seronegative gilts and then artificially inseminated these animals with extended, commercial boar semen “seeded” with difference concentrations (2, 20, 200, 2,000, 20,000, 200,000, or 2,000,000 TCID50/50 ml of semen) of the PRRSV isolate SD 92-23983. Infection of gilts by PRRSV was confirmed by weekly bleedings of these animals to detect serconversion using the commercial IDEXX ELISA. All pigs (n=7) given ≥ 200,000 doses of PRRSV seroconverted 1 to 3 weeks after insemination. In contrast, only 1/5 and 1/5 pigs serconverted at dosages of 20,000 and 2,000, respectively. There was no seroconversion (0/14 pigs) at dosages ≤ 200. Pigs, wich did not seroconvert 4 to 5 weeks after artificial insemination with semen containing 200, 2,000, and 20,000 infectious doses of PRRSV, were intranasally inoculated with the same amount of virus. After intransal challenge 4/4 (20,000 doses), 4/4 (2,000 doses) and 0/4 (200 doses) pigs seroconverted within 1 to 3 weeks after inculation. The results indicated that higher infectious does of PRRSV/ml are required for transmission via semen compared to intransal inoculation, and the nested PCR assay can detect viral RNA in semen at concentrations that do not result in transmission of PRRSV by artificial insemenation

Evaluation of a Macrophage Attenuated Isolate of PRRSV as a Vaccine for Porcine Reproductive and Respiratory Syndrome Virus

PRRS continues to be the most economically important disease of swine. While the acute reproductive disease is still prevalent, chronic, or endemic PRRS in nursery and grow/finish pigs is a major problem confronting most swine producers. Post-weaning problems in these herds include a 50-85% reduction in growth rates; a 10-30% increase in unmarketable pigs; and a 10-25% increase in psot-weaning morality. Popular protocols to manage PRRSV infections include bredding herd stabilization; elmination of seronegative sub-populations of susceptible gilts; nursery depopulation; and more recently mass vaccination/unidirectional pig flow in the grow/finsih unit. The goal of this project is to determine if an isolate of PRRSV, that has been moditifed by serial passage in monkey kidney cells (MARC-145) and replicates at very low levels in procine alveolar macrophages, is avirulent for pigs an pregnant gilts

Exploring relationships between land use intensity, habitat heterogeneity and biodiversity to identify and monitor areas of High Nature Value farming

Understanding how species richness is distributed across landscapes and which variables may be used as predictors is important for spatially targeting management interventions. This study uses finely resolved data over a large geographical area to explore relationships between land-use intensity, habitat heterogeneity and species richness of multiple taxa. It aims to identify surrogate landscape metrics, valid for a range of taxa, which can be used to map and monitor High Nature Value farmland (HNV). Results show that variation in species richness is distributed along two axes: land-use intensity and habitat heterogeneity. At low intensity land-use, species rich groups include wetland plants, plant habitat indicators, upland birds and rare invertebrates, whilst richness of other species groups (farmland birds, butterflies, bees) was associated with higher land-use intensity. Habitat heterogeneity (broadleaved woodland connectivity, hedgerows, habitat diversity) was positively related to species richness of many taxa, both generalists (plants, butterflies, bees) and specialists (rare birds, woodland birds, plants, butterflies). The results were used to create maps of HNV farmland. The proportion of semi-natural vegetation is a useful metric for identifying HNV type 1. HNV type 2 (defined as a mosaic of low-intensity habitats and structural elements) is more difficult to predict from surrogate variables, due to complex relationships between biodiversity and habitat heterogeneity and inadequacies of current remotely sensed data. This approach, using fine-scaled field survey data collected at regular intervals, in conjunction with remotely sensed data offers potential for extrapolating modelled results nationally, and importantly, can be used to assess change over time

Statistical Theory of Spin Relaxation and Diffusion in Solids

A comprehensive theoretical description is given for the spin relaxation and diffusion in solids. The formulation is made in a general statistical-mechanical way. The method of the nonequilibrium statistical operator (NSO) developed by D. N. Zubarev is employed to analyze a relaxation dynamics of a spin subsystem. Perturbation of this subsystem in solids may produce a nonequilibrium state which is then relaxed to an equilibrium state due to the interaction between the particles or with a thermal bath (lattice). The generalized kinetic equations were derived previously for a system weakly coupled to a thermal bath to elucidate the nature of transport and relaxation processes. In this paper, these results are used to describe the relaxation and diffusion of nuclear spins in solids. The aim is to formulate a successive and coherent microscopic description of the nuclear magnetic relaxation and diffusion in solids. The nuclear spin-lattice relaxation is considered and the Gorter relation is derived. As an example, a theory of spin diffusion of the nuclear magnetic moment in dilute alloys (like Cu-Mn) is developed. It is shown that due to the dipolar interaction between host nuclear spins and impurity spins, a nonuniform distribution in the host nuclear spin system will occur and consequently the macroscopic relaxation time will be strongly determined by the spin diffusion. The explicit expressions for the relaxation time in certain physically relevant cases are given.Comment: 41 pages, 119 Refs. Corrected typos, added reference

A function-based typology for Earth’s ecosystems

As the United Nations develops a post-2020 global biodiversity framework for the Convention on Biological Diversity, attention is focusing on how new goals and targets for ecosystem conservation might serve its vision of ‘living in harmony with nature’1,2. Advancing dual imperatives to conserve biodiversity and sustain ecosystem services requires reliable and resilient generalizations and predictions about ecosystem responses to environmental change and management3. Ecosystems vary in their biota4, service provision5 and relative exposure to risks6, yet there is no globally consistent classification of ecosystems that reflects functional responses to change and management. This hampers progress on developing conservation targets and sustainability goals. Here we present the International Union for Conservation of Nature (IUCN) Global Ecosystem Typology, a conceptually robust, scalable, spatially explicit approach for generalizations and predictions about functions, biota, risks and management remedies across the entire biosphere. The outcome of a major cross-disciplinary collaboration, this novel framework places all of Earth’s ecosystems into a unifying theoretical context to guide the transformation of ecosystem policy and management from global to local scales. This new information infrastructure will support knowledge transfer for ecosystem-specific management and restoration, globally standardized ecosystem risk assessments, natural capital accounting and progress on the post-2020 global biodiversity framework

Comparative empirical evaluations of internal migration models in subnational population projections

While population forecasters place considerable emphasis on the selection of appropriate migration assumptions, surprisingly little attention has been given to the effects on projection outcomes of the way internal migration is handled within population projection models. This paper compares population projections for Australia's states and territories prepared using ten different internal migration models but with identical assumptions for fertility, mortality and international migration and with the internal migration model parameters held constant. It is shown that the choice of migration model generates large differences in total population, geographical distribution and age--sex composition. It is argued that model choice should be guided by balancing model reality with practical utility and model performance is examined against these criteria. Of the ten models evaluated the authors argue that the migration pool, biregional, and biregional with net constraints models offer a good compromise between conceptual rigour and practicality. If the projected origin-destination flows are required then one of the versions of the standard multiregional model with reduced data inputs is preferred. The large variation in projection outputs points to the need for a better understanding of the spatio-temporal structure of migration in Australia

Glastir Monitoring & Evaluation Programme. Second year annual report

What is the purpose of Glastir Monitoring and Evaluation Programme? Glastir is the main scheme by which the Welsh Government pays for environmental goods and services whilst the Glastir Monitoring and Evaluation Programme (GMEP) evaluates the scheme’s success. Commissioning of the monitoring programme in parallel with the launch of the Glastir scheme provides fast feedback and means payments can be modified to increase effectiveness. The Glastir scheme is jointly funded by the Welsh Government (through the Rural Development Plan) and the EU. GMEP will also support a wide range of other national and international reporting requirements. What is the GMEP approach? GMEP collects evidence for the 6 intended outcomes from the Glastir scheme which are focussed on climate change, water and soil quality, biodiversity, landscape, access and historic environment, woodland creation and management. Activities include; a national rolling monitoring programme of 1km squares; new analysis of long term data from other schemes combining with GMEP data where possible; modelling to estimate future outcomes so that adjustments can be made to maximise impact of payments; surveys to assess wider socio-economic benefits; and development of novel technologies to increase detection and efficiency of future assessments. How has GMEP progressed in this 2nd year? 90 GMEP squares were surveyed in Year 2 to add to the 60 completed in Year 1 resulting in 50% of the 300 GMEP survey squares now being completed. Squares will be revisited on a 4 year cycle providing evidence of change in response to Glastir and other pressures such as changing economics of the farm business, climate change and air pollution. This first survey cycle collects the baseline against which future changes will be assessed. This is important as GMEP work this year has demonstrated land coming into the scheme is different in some respects to land outside the scheme. Therefore, future analysis to detect impact of Glastir will be made both against the national backdrop from land outside the scheme and this baseline data from land in scheme. A wide range of analyses of longterm data has been completed for all Glastir Outcomes with the exception of landscape quality and historic features condition for which limited data is available. This has involved combining data with 2013/14 GMEP data when methods allow. Overall analysis of long term data indicates one of stability but with little evidence of improvement with the exception of headwater quality, greenhouse gas emissions and woodland area for which there has been improvement over the last 20 years. Some headline statistics include: 51% of historic features in excellent or sound condition; two thirds of public rights of way fully open and accessible; improvement in hedgerow management with 85% surveyed cut in the last 3 years but < 1% recently planted; 91% of streams had some level of modification but 60% retained good ecological quality; no change topsoil carbon content over last 25 years. What is innovative? GMEP has developed various new metrics to allow for more streamlined reporting in the future. For example a new Priority Bird species Index for Wales which combines data from 35 species indicates at least half have stable or increasing populations. The new GMEP Visual Quality Landscape Index has been tested involving over 2600 respondents. Results have demonstrated its value as an objective and repeatable method for quantifying change in visual landscape quality. A new unified peat map for Wales has been developed which has been passed to Glastir Contract Managers to improve targeting of payments when negotiating Glastir contracts. An estimate of peat soil contribution to current greenhouse gas emissions due to human modification has been calculated. Models have allowed quantification of land area helping to mitigate rainfall runoff. We are using new molecular tools to explore the effects of Glastir on soil organisms and satellite technologies to quantify e.g. small woody features and landcover change. Finally we are using a community approach to develop a consensus on how to define and report change in High Nature Value Farmland which will be reported in the Year 3 GMEP report

Glastir Monitoring & Evaluation Programme. Final report

Final Report to Welsh Government, prepared by CEH on behalf of the Glastir Monitoring & Evaluation Programme Team. The Glastir Monitoring and Evaluation Programme (GMEP) provides a comprehensive programme to establish a baseline against which future assessments of Glastir can be made. GMEP also contributes national trend data which supports a range of national and international biodiversity and environmental targets. GMEP fulfils a commitment by the Welsh Government to establish a monitoring programme concurrently with the launch of the Glastir scheme. The use of models and farmer surveys provides early indicators of the likely direction, magnitude and timing of future outcomes. The programme ensures compliance with the rigorous requirements of the European Commission’s Common Monitoring and Evaluation Framework (CMEF) through the Rural Development Plan (RDP) for Wales. This report represents the final results of the GMEP programme which ran from 2012 to 2016