87 research outputs found
OPTIMAL HOG SLAUGHTER WEIGHTS UNDER ALTERNATIVE PRICING SYSTEMS
Three hog genotypes are simulated to determine how producer profits, economically optimal slaughter weights, and carcass component weights change under three pricing models. Live weight pricing pays more for the fatter barrows whereas a three component (separate payments for fat, lean, and byproducts) and six component (separate payments for major primal cuts, other lean, fat, and byproducts) pricing system pay more for the leaner gilts. Implications for selection of genetic stock and pricing system are presented.Swine production management, Hog pricing systems, Hog marketing, Livestock Production/Industries,
ECONOMIC REPLACEMENT OF A HETEROGENEOUS HERD
A model was developed and used to determine the optimal slaughter weights of pigs with heterogeneous growth raised in a 1,000 head barn and marketed in truckload groups. Explicitly recognizing the heterogeneity of pig weights and marketing the herd over time in truckload batches can substantially increase profit.Marketing,
The New Economics of Livestock Production Management
The importance of heterogeneity of animal attributes in livestock production is assessed. Preliminary results indicate that variance and skew measures of attributes may be becoming more important over time.livestock economics, herd management, livestock marketing, Livestock Production/Industries, Marketing,
Agricultural resource and risk management with multiperiod stochastics: A case of the mixed crop-livestock production system in the drylands of Jordan
Generally, agricultural production involves several challenges. In the drylands, it is further complicated by weather-related risks and resource degradation. In this paper, we present a case study of the mixed crop-livestock production system in Jordan. To better capture the nature of response farming in the drylands, we develop a methodology for using crop simulation models to directly generate data for optimizing production practices of an integrated crop-livestock producing household in a dynamic stochastic context. The approach optimizes producer's adaptations to random events, such as weather, which are realized throughout the planning horizon. To ensure the sustainability of the optimized production decisions, long-term valuations of end of horizon soil attributes are included in the objective function. This approach endogenizes the tradeoff between short-and long-run productivity. Model results show that due to the limited natural resource endowments and financial liquidity constraints of the typical farm households in the study area, we find these households have limited options. To optimally respond to weather conditions during the production season, better manage risk, and achieve improvements in soil attributes, a typical household would need larger farm size, larger flock, and better financial liquidity than it currently commands. Like all such models, the farm household model used in this paper is not suitable for drawing policy implications. Therefore, targeted analysis using appropriate sectoral or economy-wide models will be needed in the future to identify and test the efficacy of different policy and institutional interventions including land consolidation, establishment of producer and marketing cooperatives, access to financial services including agricultural credit, and crop insurance in expanding the resource base of farmers-thereby positioning them for higher earnings, ensuring soil conservation, and enhancing the sustainability of the production system
Assessment of reward-related brain function after a single-dose of oxytocin in autism: A randomized controlled trial
Background Autism spectrum disorder (ASD) is characterized by difficulties in social communication and interaction, which have been related to atypical neural processing of rewards, especially in the social domain. Since intranasal oxytocin has been shown to modulate activation of the brain’s reward circuit, oxytocin might ameliorate the processing of social rewards in ASD and thus improve social difficulties. Methods In this randomized, double-blind, placebo-controlled, crossover fMRI study, we examined effects of a 24 IU dose of intranasal oxytocin on reward-related brain function in 37 men with ASD without intellectual impairment and 37 age- and IQ-matched control participants. Participants performed an incentive delay task that allows the investigation of neural activity associated with the anticipation and receipt of monetary and social rewards. Results Non-significant tests suggested that oxytocin did not influence neural processes related to the anticipation of social or monetary rewards in either group. Complementary Bayesian analyses indicated moderate evidence for a null model, relative to an alternative model. Our results are inconclusive regarding possible oxytocin effects on amygdala responsiveness to social rewards during reward consumption. There were no significant differences in reward-related brain function between the two groups under placebo. Conclusions Our results do not support the hypothesis that intranasal oxytocin generally enhances activation of reward-related neural circuits in men with and without ASD
Gender Differences in Myogenic Regulation along the Vascular Tree of the Gerbil Cochlea
Regulation of cochlear blood flow is critical for hearing due to its exquisite sensitivity to ischemia and oxidative stress. Many forms of hearing loss such as sensorineural hearing loss and presbyacusis may involve or be aggravated by blood flow disorders. Animal experiments and clinical outcomes further suggest that there is a gender preference in hearing loss, with males being more susceptible. Autoregulation of cochlear blood flow has been demonstrated in some animal models in vivo, suggesting that similar to the brain, blood vessels supplying the cochlea have the ability to control flow within normal limits, despite variations in systemic blood pressure. Here, we investigated myogenic regulation in the cochlear blood supply of the Mongolian gerbil, a widely used animal model in hearing research. The cochlear blood supply originates at the basilar artery, followed by the anterior inferior cerebellar artery, and inside the inner ear, by the spiral modiolar artery and the radiating arterioles that supply the capillary beds of the spiral ligament and stria vascularis. Arteries from male and female gerbils were isolated and pressurized using a concentric pipette system. Diameter changes in response to increasing luminal pressures were recorded by laser scanning microscopy. Our results show that cochlear vessels from male and female gerbils exhibit myogenic regulation but with important differences. Whereas in male gerbils, both spiral modiolar arteries and radiating arterioles exhibited pressure-dependent tone, in females, only radiating arterioles had this property. Male spiral modiolar arteries responded more to L-NNA than female spiral modiolar arteries, suggesting that NO-dependent mechanisms play a bigger role in the myogenic regulation of male than female gerbil cochlear vessels
Effect of remote ischemic conditioning on atrial fibrillation and outcome after coronary artery bypass grafting (RICO-trial)
Background: Pre- and postconditioning describe mechanisms whereby short ischemic periods protect an organ against a longer period of ischemia. Interestingly, short ischemic periods of a limb, in itself harmless, may increase the ischemia tolerance of remote organs, e.g. the heart (remote conditioning, RC). Although several studies have shown reduced biomarker release by RC, a reduction of complications and improvement of patient outcome still has to be demonstrated. Atrial fibrillation (AF) is one of the most common complications after coronary artery bypass graft surgery (CABG), affecting 27-46% of patients. It is associated with increased mortality, adverse cardiovascular events, and prolonged in-hospital stay. We hypothesize that remote ischemic pre- and/or post-conditioning reduce the incidence of AF following CABG, and improve patient outcome.Methods/design: This study is a randomized, controlled, patient and investigator blinded multicenter trial. Elective CABG patients are randomized to one of the following four groups: 1) control, 2) remote ischemic preconditioning, 3) remote ischemic postconditioning, or 4) remote ischemic pre- and postconditioning. Remote conditio
Neck disorder influenced by occupational reward type: Results from effort-reward imbalance model based on IPWS
Effort-Reward Imbalance model is known as one of the survey method of occupational stress and also as an effective element on health condition according to its parameters. Due to types of rewards generally, and reward subscales in this model specifically, each one can have a distinctive effect on health perception, current study is aimed at determination of the most effective reward subscale for managing work-related neck disorder in industries. All of workers who participated in IPWS study (N = 1126), were entered in the statistical analysis stage. After completing personal and organizational information, they responded to Van Vegchel et al. Effort-Reward Imbalance and also Dutch questionnaires for their musculoskeletal disorders. Chi-square and t-test comparisons were performed and the final regression model was presented with a significance level of 0.05. The mean (Standard deviation) age of workers and musculoskeletal disorders prevalence in neck were 33.21 (7.63) years and 34 percent respectively. Also in workers with neck pain, odds ratio between effort and monetary reward, between effort and respect reward, and between effort and security reward in their jobs were 1.35, 2.07 and 1.32 respectively. After elimination of confounders in final regression model, significant correlation was remained only between effort and job respect reward. According to high prevalence of musculoskeletal disorders in neck and also large amount of effort-reward imbalance in Iranian workers, implementing interventions are recommended. Based on results of present study, it is suggested that main intervention must be focused on respect and esteem reward in jobs. © Springer Nature Switzerland AG 2019
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