Dominos in the dairy: An analysis of transgenic maize in Dutch dairy farming

Isolation distances to limit the risk of cross-pollination from transgenic to nontransgenic crops can severely limit the potential use of transgenic crops through a so-called 'domino effect' where a field of non-transgenic crops limits adoption of transgenic crops not only on plots in its direct vicinity, but also in plots further away as its neighbors are forced to grow the non-transgenic varieties, forcing their neighbors to grow the non-transgenic variety, and so on. The extent to which this effect takes place, however, may depend crucially on the type of farm. For example, dairy farms can use grassland as a buffer between transgenic and conventional maize plots. This article assesses the effects of isolation distances for transgenic maize in dairy farming. A spatially explicit farm model is applied to a region in the Southern Netherlands to identify to what extent a single farmer (who uses non-transgenic maize) can limit other farmers’ potential to grow transgenic maize. The main findings are that 50% or more of the farms in the study area will not affect the potential adoption of transgenic maize by growing conventional maize at all. This result even holds under distance measures of 800m, which is the largest distance implemented by member states of the European Union. When they do have such effects, isolation distances can reduce the benefits from transgenic maize by €5,000 - €6,000, for a considerable part through a domino effect. Large net benefits of transgenic maize may limit the spatial effects as farmers are more willing to relocate maize production to areas where transgenic maize is allowed.Crop Production/Industries, Livestock Production/Industries,

Development of nature-oriented dairy farm systems with an optimization model: the case of ‘Farming for Nature’ in ‘de Langstraat’, the Netherlands

‘Farming for Nature’, a relatively new policy instrument being tried out in the Netherlands, is evaluated. The concept has been designed to allow dairy farmers to improve nature conservation on their farms. Under the scheme, no manure, fertilizer, or feed – concentrates or roughage - may be imported into farm systems from external sources. The feasibility of such a self-sustaining system and the conditions required for it to deliver the desired results, are explored with a farm-based linear programming model known as FIONA (Farm based Integrated Optimization Model for Nature and Agriculture). The model is explained and applied to ‘de Langstraat’, a region in southern Netherlands. The results show that levels of production under the ‘Farming for Nature’ regime are dependent upon soil fertility and the proportion of land that is suitable for growing arable crops. If all available land on a dairy farm in the scheme is arable land, then high production levels of up to 7,500 kg milk per hectare can be realized. If only 30% of the farm area is suitable for arable crops, then only lower production levels, of about 6,600 kg milk per hectare can be realized. The scheme has positive ecological effects. Both nature and cultural landscape values may benefit significantly from the concept. Improvement in ecological terms however, carries a price in terms of agricultural income. An average dairy farm adopting the concept of ‘Farming for Nature’ experiences an income loss of approximately € 840 per hectare in the short-run (5-10 years). More important is the observation that the scale of such farms in the short-run might be too small to earn an attractive income for its workers, even when fully compensated according to European Union regulations.nature management, dairy farming system, linear programming, farm-economics, Farm Management, Land Economics/Use,

RESEARCH STRATEGIES OF THE NATIONAL WILDLIFE RESEARCH CENTER TO CONTROL BOVINE TUBERCULOSIS IN WILDLIFE IN MICHIGAN, USA

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobaterium bovis and is transmissible to humans, wildlife, and domestic livestock. In the United Kingdom, the suspected wildlife reservoir of bTB is the badger (Meles meles) (HUTCHINGS and HARRIS, 1 997), and in New Zealand, the culprit is the brush-tailed possum (Trichosurus vulpecula) (MORRIS et al., 1994). In northern Michigan, USA, bovine tuberculosis is endemic in white-tailed deer (Odocoileus virginianus). In 1975 a hunter-killed white-tailed deer in Alpena County, Michigan, USA, was tested positive for bTB. Subsequent surveillance by the Michigan Department of Natural Resources (MDNR) of hunter-killed deer revealed no additional cases, and the situation was ruled an anomaly. However, in 1994, an additional hunter-killed white-tailed deer tested positive for bTB in Alcona County, only 13 km from the 1975 case. Between 1995 and 2005, a total of 509 deer tested positive for the disease (MDNR, 2005) and evidence suggested that deer transmitted the disease to domestic cattle (PALMER et al., 2004a). From 1997 to 2004, 33 cattle herds and 1 captive cervid farm tested positive for bTB (MDNR, 2005), most of them within a 5- county area. In addition, in 2006, 6 cattle farms and 1 captive cervid farm tested positive for the disease (MDNR, personal communication). In response to this outbreak, in the past several years MDNR has implemented management strategies to reduce the prevalence of bTB in deer in the outbreak area. These include reduction of deer densities through liberal hunting and restriction of baiting and supplemental feeding of white-tailed deer to reduce deer densities. In addition, Michigan Department of Agriculture and USDA/APHIS/Veterinary Services actively test cattle and captive deer herds with subsequent depopulation of infected herds. And while these actions have reduced the apparent prevalence of bTB in deer from 4.7 % to 1.7 %, a 64 % reduction (MDNR, 2005), other wildlife species may act as reservoirs for the disease. Bovine tuberculosis has been documented in many species of wildlife, including raccoons (Procyon lotor), coyotes (Canis latrans), red fox (Vulpes vulpes) and black bear (Ursus americanus) (BRUNING-FANN et al., 2001). In the outbreak area, bTB prevalence estimates in coyotes and raccoons are as high as 24% (VERCAUTEREN et al., unpublished data) and 2.5 % (WITMER et al., unpublished data), respectively. This raises the question of whether infected raccoons and coyotes actively shed M. bovis through either feces or oral/nasal secretions, thus increasing risks of infection to cattle and other wildlife

The Societal Benefit of a Financial Transaction Tax

We provide a novel justification for a financial transaction tax for economies where agents face stochastic consumption opportunities. A financial transaction tax makes it more costly for agents to readjust their portfolios of liquid and illiquid assets in response to liquidity shocks, which increase both the demand for and the price of liquid assets. The higher price improves liquidity insurance and welfare for other market participants. We calibrate the model to U.S. data and find that the optimal financial transaction tax is 1.6% and that it reduces the volume of financial trading by 17%

Limited Commitment and the Demand for Money

Understanding money demand is important for our comprehension of macroeconomics and monetary policy. Its instability has made this a challenge. Common explications for the instability are financial regulations and financial innovations that shift the money demand function. We provide a complementary view by showing that a model where borrowers have limited commitment can significantly improve the fit between the theoretical money demand function and the data. Limited commitment can also explain why the ratio of credit to M1 is currently so low, despite that nominal interest rates are at their lowest recorded levels

The heritability of BMI varies across the range of BMI-a heritability curve analysis in a twin cohort

Background The heritability of traits such as body mass index (BMI), a measure of obesity, is generally estimated using family and twin studies, and increasingly by molecular genetic approaches. These studies generally assume that genetic effects are uniform across all trait values, yet there is emerging evidence that this may not always be the case. Method/Subjects This paper analyzes twin data using a recently developed measure of heritability called the heritability curve. Under the assumption that trait values in twin pairs are governed by a flexible Gaussian mixture distribution, heritability curves may vary across trait values. The data consist of repeated measures of BMI on 1506 monozygotic (MZ) and 2843 like-sexed dizygotic (DZ) adult twin pairs, gathered from multiple surveys in older Finnish Twin Cohorts. Results The heritability curve and BMI value-specific MZ and DZ pairwise correlations were estimated, and these varied across the range of BMI. MZ correlations were highest at BMI values from 21 to 24, with a stronger decrease for women than for men at higher values. Models with additive and dominance effects fit best at low and high BMI values, while models with additive genetic and common environmental effects fit best in the normal range of BMI. Conclusions We demonstrate that twin and molecular genetic studies need to consider how genetic effects vary across trait values. Such variation may reconcile findings of traits with high heritability and major differences in mean values between countries or over time.Peer reviewe

Capture-Recapture Reveals Heterogeneity in Habitat-Specific Mongoose Densities and Spatiotemporal Variability in Trapping Success in St. Kitts, West Indies

The small Indian mongoose (Urva auropunctata) is a non-native invasive species across the Caribbean and a rabies reservoir on at least four islands in the region. Although previous studies reported mongoose density estimates in their non-native range, the variability in trapping designs, study seasonality, and analytical methods among studies precludes direct comparisons. This study is the first to report mongoose densities for the island of St. Kitts, West Indies. Our objective was to quantify mongoose densities across four habitats characteristic for the island. High capture and recapture rates in this study resulted in detailed estimates of spatial heterogeneity in mongoose densities, ranging from 0.53 (CI95: 0.46–0.61) mongooses/ha in suburban habitat to 5.85 (CI95: 4.42–7.76) mongooses/ha in nearby dry forest. Estimates were robust to the estimation method used (correlation among methods, r \u3e 0.9). Female-biased sex ratios estimated from fall season versus mostly unbiased sex ratios estimated from summer season suggests seasonality in capture success resulting from differences in sex-specific activity patterns of mongooses. We found no effect of habitat characteristics, at the scale of trap placements, associated with mongoose capture success

Modeling Mongoose Rabies in the Caribbean: A Model-Guided Fieldwork Approach to Identify Research Priorities

We applied the model-guided fieldwork framework to the Caribbean mongoose rabies system by parametrizing a spatially-explicit, individual-based model, and by performing an uncertainty analysis designed to identify parameters for which additional empirical data are most needed. Our analysis revealed important variation in output variables characterizing rabies dynamics, namely rabies persistence, exposure level, spatiotemporal distribution, and prevalence. Among epidemiological parameters, rabies transmission rate was the most influential, followed by rabies mortality and location, and size of the initial infection. The most influential landscape parameters included habitat-specific carrying capacities, landscape heterogeneity, and the level of resistance to dispersal associated with topography. Movement variables, including juvenile dispersal, adult fine-scale movement distances, and home range size, as well as life history traits such as age of independence, birth seasonality, and age- and sex-specific mortality were other important drivers of rabies dynamics. We discuss results in the context of mongoose ecology and its influence on disease transmission dynamics. Finally, we suggest empirical approaches and study design specificities that would provide optimal contributing data addressing the knowledge gaps identified by our approach, and would increase our potential to use epidemiological models to guide mongoose rabies control and management in the Caribbean

\u3ci\u3eBOA CONSTRICTOR\u3c/i\u3e (Boa Constrictor)

USA: PUERTO RICO: MUNICIPALITY OF CABO ROJO: Cabo Rojo National Wildlife Refuge (17.978958°N, 67.170910oW; NAD 83). 10 November 2014. O. A. Diaz-Marrero. Verified by S. M. Boback. National Museum of Natural History, Smithsonian Institution (USNM Herp Image 2838a, b; photo vouchers). First municipality record for this exotic species; all previous reports were restricted to the Municipality of Mayaguez, located ca. 25 km north of Cabo Rojo National Wildlife Refuge. Reynolds et al. (2013. BioI. Invasions 15:953-959) concluded that Boa Constrictor introductions into Puerto Rico were likely related to the pet trade and that they genetically matched snakes belonging to the South American clade (B. constrictor), instead of B. imperator, the Mesoamerican species (Hynkova et al. 2009. Zool. Sci. 26:623-631). It also represents the first report of this species from a protected area in Puerto Rico