906 research outputs found
Leading Digit Laws on Linear Lie Groups
We determine the leading digit laws for the matrix components of a linear Lie
group . These laws generalize the observations that the normalized Haar
measure of the Lie group is and that the scale invariance
of implies the distribution of the digits follow Benford's law, which is
the probability of observing a significand base of at most is
; thus the first digit is with probability ).
Viewing this scale invariance as left invariance of Haar measure, we determine
the power laws in significands from one matrix component of various such .
We also determine the leading digit distribution of a fixed number of
components of a unit sphere, and find periodic behavior when the dimension of
the sphere tends to infinity in a certain progression.Comment: Version 1.0, 17 pages, 1 figur
An International Comparison of the Effects of Government Agricultural Support on Food Budget Shares
This study evaluates econometrically the effect of government support to agriculture on a measure of the affordability of food in 10 Organization for Economic Cooperation and Development (OECD) countries. The panel model we construct specifically utilizes two values calculated by the OECD: Producer Support Estimates as a percentage of gross farm receipts and the Consumer Nominal Protection Coefficient. These two variables represent transfers from taxpayers to agricultural producers through government programs and transfers from consumers to government through protectionist measures, respectively. By using dummy variables, we find implications for groups of countries on the basis of their relative levels of support and protection.agricultural policy, obesity, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety, I18, Q18,
Incentives Matter: Assessing Biofuel Policies in the South
As a result of the increase in the real cost of fossil fuel-based energy in recent years, federal and state governments have taken a more active role in energy policy by creating incentives to develop alternative sources of energy, including biofuels. However, policymakers often become focused on the specific type of energy and not the energy services consumers ultimately value. The lack of recognition of energy as a commodity results in policies that ignore the characteristics of the associated markets: easy entry and exit, no barriers to entry, and sensitivity to changes in supply and demand. Consequently, energy industries may fail to arise because entrepreneurs must be able to account for all costs and earn—at a minimum—a competitive return on the investment. This article evaluates the options available to policymakers related to biofuels, which are of particular concern to the South, and includes an assessment of the knowledge base on which policy decisions are made.alternative energy, biofuels, energy policy, Resource /Energy Economics and Policy, Q41, Q42, Q48,
INVESTIGATING THE IMPLICATIONS OF MULTI-CROP REVENUE INSURANCE FOR PRODUCER RISK MANAGEMENT
This study investigates the potential for alternative multi-crop revenue insurance designs in comparison to single crop yield and revenue insurance designs. A non-parametric multi-crop insurance model is developed which subsumes the single crop designs. The results compare alternative designs in terms of rate levels and risk reduction gains for representative Mississippi producers.crop insurance, revenue insurance, risk, Risk and Uncertainty,
The Effect of Changing Government Subsidy Programs: An Analysis of Revenue at the Farm level
Producer revenue is simultaneously simulated for several hundred county-specific representative farms. The effects of current and alternative commodity programs are analyzed. In particular, two variations of revenue-triggered programs similar to plans proposed by the National Corn Growers Association are evaluated.Risk, commodity policy, simulation, Agricultural and Food Policy, Risk and Uncertainty, Q180,
Crop Supply Response under Risk: Impacts of Emerging Issues on Southeastern U.S. Agriculture
In this paper we consider factors that affect both crop prices and yields in order to examine supply responses of major crops in the Southeast. Due to the variable nature of crop production in the Southeast, previous studies that ignore price and yield risk may fail to capture one of the salient features of the region’s agriculture. Our results indicate supply elasticity values for corn, cotton, and soybeans of approximately 0.670, 0.506, and 0.195, respectively. Compared with the results of studies in other regions, corn and cotton acres respond more to price changes and soybean acres respond less to price changes.acreage supply, crop supply response model, risk analysis, Southeast U.S. agriculture, Crop Production/Industries, Production Economics, Q12, Q13, Q16,
Summer habitat use and movements of invasive wild pigs (Sus scrofa) in Canadian agro-ecosystems
Resource selection informs understanding of a species’ ecology and is especially pertinent for invasive species. Since introduced to Canada, wild pigs (Sus scrofa Linnaeus, 1978) remain understudied despite recognized negative impacts on native and agricultural systems globally. Elsewhere in North America, pigs typically use forests and forage in agricultural crops. We hypothesized Canadian wild pigs would behave similarly, and using GPS locations from 15 individuals, we examined diel and seasonal resource selection and movement in the Canadian prairie region. Forests were predominately selected during the day, while corn (Zea mays L.), oilseeds, and wheat (Triticum aestivum L.) were predominately selected at night. Forests and corn were consistently selected throughout the growing season.Wetlands and forests showed greater use rates than other habitats, with evident trade-offs as crop use increased with the timing of maturation. Activity was consistent with foraging in growing crops. Results indicate diel patterns were likely a function of short-term needs to avoid daytime anthropogenic risk, while seasonal patterns demonstrate how habitats that fill multiple functional roles——food, cover, and thermoregulation——can be optimized. Understanding selection by invasive species is an important step in understanding their potential environmental impacts in novel environments and informs their management
The adventure sports coach: All show and no substance?
The primary objective of this research was to establish the range of interpersonal strategies, tools and techniques used by adventure sports coaches (ASCs) to influence participants’ actions and behaviours, and to determine where these strategies were acquired. An interpretative approach was employed using semi-structured interviews with a convenience sample of expert paddlesport coaches (n = 4). Interpretative phenomenological analysis was used to get close to the data and identify salient topics. Five themes were subsequently identified as fundamental to effective coach–participant interaction: appropriate environment, stories told, knowing the participant, formal training and situational context. The implications are that whilst ASCs have well-developed intuitive social engagement skills, these are not consciously or declaratively employed in coaching sessions, and neither are they used at strategic levels to enhance participant development. Therefore, a multi-layer approach is recommended to help ASCs access and employ these skills that has consequences for the education, training and continued professional development of ASCs
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Acute Infection and Subsequent Subclinical Reactivation of Herpes Simplex Virus 2 after Vaginal Inoculation of Rhesus Macaques.
Herpes simplex virus 2 (HSV-2) is a common sexually transmitted infection with a highly variable clinical course. Many infections quickly become subclinical, with episodes of spontaneous virus reactivation. To study host-HSV-2 interactions, an animal model of subclinical HSV-2 infection is needed. In an effort to develop a relevant model, rhesus macaques (RM) were inoculated intravaginally with two or three HSV-2 strains (186, 333, and/or G) at a total dose of 1 × 107 PFU of HSV-2 per animal. Infectious HSV-2 and HSV-2 DNA were consistently shed in vaginal swabs for the first 7 to 14 days after each inoculation. Proteins associated with wound healing, innate immunity, and inflammation were significantly increased in cervical secretions immediately after HSV-2 inoculation. There was histologic evidence of acute herpesvirus pathology, including acantholysis in the squamous epithelium and ballooning degeneration of and intranuclear inclusion bodies in epithelial cells, with HSV antigen in mucosal epithelial cells and keratinocytes. Further, an intense inflammatory infiltrate was found in the cervix and vulva. Evidence of latent infection and reactivation was demonstrated by the detection of spontaneous HSV-2 shedding post-acute inoculation (102 to 103 DNA copies/swab) in 80% of RM. Further, HSV-2 DNA was detected in ganglia in most necropsied animals. HSV-2-specifc T-cell responses were detected in all animals, although antibodies to HSV-2 were detected in only 30% of the animals. Thus, HSV-2 infection of RM recapitulates many of the key features of subclinical HSV-2 infection in women but seems to be more limited, as virus shedding was undetectable more than 40 days after the last virus inoculation.IMPORTANCE Herpes simplex virus 2 (HSV-2) infects nearly 500 million persons globally, with an estimated 21 million incident cases each year, making it one of the most common sexually transmitted infections (STIs). HSV-2 is associated with increased human immunodeficiency virus type 1 (HIV-1) acquisition, and this risk does not decline with the use of antiherpes drugs. As initial acquisition of both HIV and HSV-2 infections is subclinical, study of the initial molecular interactions of the two agents requires an animal model. We found that HSV-2 can infect RM after vaginal inoculation, establish latency in the nervous system, and spontaneously reactivate; these features mimic some of the key features of HSV-2 infection in women. RM may provide an animal model to develop strategies to prevent HSV-2 acquisition and reactivation
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Assessment of abdominal fat compartments using DXA in premenopausal women from anorexia nervosa to morbid obesity
Objective: The purpose of this study was to test a newly developed DXA method for abdominal fat depot quantification in subjects with AN, normal weight, and obesity using CT as a gold standard. Design and Methods 135 premenopausal women (overweight/obese: n=89, normal-weight: n=27, AN: n=19); abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and total adipose tissue (TAT) areas determined on CT and DXA. Results: There were strong correlations between DXA and CT measurements of abdominal fat compartments in all groups with the strongest correlation coefficients in the normal-weight and overweight/obese groups. Correlations of DXA and CT VAT measurements were strongest in the obese group and weakest in the AN group. DXA abdominal fat depots were higher in all groups compared to CT, with the largest % mean difference in the AN group and smallest in the obese group. Conclusions: A new DXA technique is able to assess abdominal fat compartments including VAT in premenopausal women across a large weight spectrum However, DXA measurements of abdominal fat were higher than CT, and this percent bias was most pronounced in the AN subjects and decreased with increasing weight, suggesting that this technique may be more useful in obese individuals
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