188 research outputs found
ANTICIPATORY HEDGING WITH TREASURY BILLS: THE CASE OF A BANK FOR COOPERATIVES
Agricultural cooperatives find it difficult to forecast their interest costs and net income. If input and output prices are fixed, anticipatory hedging of future interest costs is appropriate. Banks for Cooperatives obtain funds in maturities longer than the three months of Treasury bills. Hence, anticipatory hedging of interest rates may require selling a "strip" of more than one Treasury bill futures contract. Adapting Peck's model of hedges against forecast error, hedge ratios generally exceed one-for-one, "naïve" hedging, with effectiveness generally above 95 percent. Hedges closed out just before a delivery date have the highest effectiveness.Agribusiness, Financial Economics,
Traction forces generated during studded boot‐surface interactions on third‐generation artificial turf: A novel mechanistic perspective
The traction forces generated during studded boot–surface
interactions affect player performance and injury risk. Over
20 years of empirical research into traction on third
generation (3G) artificial turf has met with only limited
success in supporting the development of safer surfaces and
boots. Thus, the purpose of this perspective article is to
present a conceptual framework for generating scientific
understanding on 3G turf traction through a novel
mechanistic approach. A three-stage framework is
proposed. Firstly, the hypothesized traction mechanisms
and related analytical equations are identified, namely:
friction between the boot outsole and surface; shear
resistance of the performance infill layer to the outsole; and
compressive resistance of the performance infill layer to
horizontal stud displacement. Secondly, a Concept Map is
generated to visually represent the contribution of the thirtynine variables identified as directly affecting the traction
response. Finally, a Research Roadmap is constructed to
guide the direction of future traction studies towards the
development of safer surfaces and boots as well as improved
mechanical tests to assess surface safety. The proposed
framework represents the first attempt to deconstruct bootsurface interactions and hypothesize the science behind the
mobilization of traction forces
Comparative Judgement Modeling to Map Forced Marriage at Local Levels
Forcing someone into marriage against their will is a violation of their
human rights. In 2021, the county of Nottinghamshire, UK, launched a strategy
to tackle forced marriage and violence against women and girls. However,
accessing information about where victims are located in the county could
compromise their safety, so it is not possible to develop interventions for
different areas of the county. Comparative judgement studies offer a way to map
the risk of human rights abuses without collecting data that could compromise
victim safety. Current methods require studies to have a large number of
participants, so we develop a comparative judgement model that provides a more
flexible spatial modelling structure and a mechanism to schedule comparisons
more effectively. The methods reduce the data collection burden on participants
and make a comparative judgement study feasible with a small number of
participants. Underpinning these methods is a latent variable representation
that improves on the scalability of previous comparative judgement models. We
use these methods to map the risk of forced marriage across Nottinghamshire
thereby supporting the county's strategy for tackling violence against women
and girls.Comment: Submitted. 31 pages, 8 figure
Genomics reveals the history of a complex plant invasion and improves the management of a biological invasion from the South African-Australian biotic exchange
Many plants exchanged in the global redistribution of species in the last 200 years, particularly between South Africa and Australia, have become threatening invasive species in their introduced range. Refining our understanding of the genetic diversity and population structure of native and alien populations, introduction pathways, propagule pressure, naturalization, and initial spread, can transform the effectiveness of management and prevention of further introductions. We used 20,221 single nucleotide polymorphisms to reconstruct the invasion of a coastal shrub, Chrysanthemoides monilifera ssp. rotundata (bitou bush) from South Africa, into eastern Australia (EAU), and Western Australia (WAU). We determined genetic diversity and population structure across the native and introduced ranges and compared hypothesized invasion scenarios using Bayesian modeling. We detected considerable genetic structure in the native range, as well as differentiation between populations in the native and introduced range. Phylogenetic analysis showed the introduced samples to be most closely related to the southern-most native populations, although Bayesian analysis inferred introduction from a ghost population. We detected strong genetic bottlenecks during the founding of both the EAU and WAU populations. It is likely that the WAU population was introduced from EAU, possibly involving an unsampled ghost population. The number of private alleles and polymorphic SNPs successively decreased from South Africa to EAU to WAU, although heterozygosity remained high. That bitou bush remains an invasion threat in EAU, despite reduced genetic diversity, provides a cautionary biosecurity message regarding the risk of introduction of potentially invasive species via shipping routes
Renal artery stenosis-when to screen, what to stent?
Renal artery stensosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed
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