THE BAYESIAN DECISION MODEL WITH MORE THAN ONE PREDICTOR--AN APPLICATION TO THE STOCKING RATE PROBLEM

Research Methods/ Statistical Methods,

Postal survey of contacts between cattle farms on the Isle of Lewis

The British Cattle Movement Service (BCMS) database contains an unprecedented quantity of data on the movement of cattle within the UK. These data may be used to construct models of the contact structure of the UK cattle herd, for epidemiological purposes. There are two significant potential sources of inaccuracy within such models: movements that are not reported or are reported inaccurately to the BCMS, and contacts between farms that might transmit infection, but are not animal movements. This field study addressed these issues. Cattle farmers on the Isle of Lewis were recruited with the assistance of the local veterinary surgeon, and asked to record a range of potential risk behaviours for a one-month period. They were also asked questions about husbandry practices on their farm. Comparison of the BCMS contact data with that reported by Lewis' farmers highlighted use of common grazing land as a significant source of contact, and potential disease transmission, between cattle that currently goes unreported; around half of responding holdings on Lewis use common grazing land at some point during the year, and these movements are not reported to the BCMS

Flow Dynamics And Plasma Heating Of Spheromaks In SSX

We report several new experimental results related to flow dynamics and heating from single dipole-trapped spheromaks and spheromak merging studies at SSX. Single spheromaks (stabilized with a pair of external coils, see Brown, Phys. Plasmas 13 102503 (2006)) and merged FRC-like configurations (see Brown, Phys. Plasmas 13, 056503 (2006)) are trapped in our prolate (R = 0.2 m, L = 0.6 m) copper flux conserver. Local spheromak flow is studied with two Mach probes (r(1) = rho(i) ) calibrated by time-of-flight with a fast set of magnetic probes at the edge of the device. Both Mach probes feature six ion collectors housed in a boron nitride sheath. The larger Mach probe will ultimately be used in the MST reversed field pinch. Line averaged flow is measured by ion Doppler spectroscopy (IDS) at the midplane. The SSX IDS instrument measures with 1 mu s or better time resolution the width and Doppler shift of the C-III impurity (H plasma) 229.7 nm line to determine the temperature and line-averaged flow velocity (see Cothran, RSI 77, 063504 (2006)). We find axial flows up to 100 km/s during formation of the dipole trapped spheromak. Flow returns at the wall to form a large vortex. Recent high-resolution IDS velocity measurements during spheromak merging show bi-directional outflow jets at +/- 40 km/s (nearly the Alfven speed). We also measure T-i \u3e= 80 eV and T-e \u3e= 20 eV during spheromak merging events after all plasma facing surfaces are cleaned with helium glow discharge conditioning. Transient electron heating is inferred from bursts on a four-channel soft x-ray array. The spheromaks are also characterized by a suite of magnetic probe arrays for magnetic structure B(r,t), and interferometry for n(e) . Finally, we are designing a new oblate, trapezoidal flux conserver for FRC studies. Equilibrium and dynamical simulations suggest that a tilt-stable, oblate FRC can be formed by spheromak merging in the new flux conserver

Freshman Course Credit and Unexcused Absences: An Arkansas Policy Analysis

This policy analysis examines the implementation of A.C.A. 6-18-222, a statewide policy in Arkansas that addresses unexcused absences and course credit consequences for students. Using anonymized student-level data from the 2020-21 and 2021-22 school years (N=65,651), the study explores variations in policy implementation across districts and investigates the relationship between absences and course failures for freshmen. Our results highlight the wide variability in the number of allowed unexcused absences and the language of course credit consequence among districts. Additionally, our multivariate logistic regressions reveal FRL-eligible students more likely to fail a course after reaching their district’s unexcused absence threshold. Lastly, we find once students reach their district’s unexcused absence threshold, they more likely to fail a core course compared to a non-core course. Our findings provide insights into the variations of local policy implementation for student academic outcomes

Freshman Course Credit and Unexcused Absences: An Arkansas Policy Analysis

This policy analysis examines the implementation of A.C.A. 6-18-222, a statewide policy in Arkansas that addresses unexcused absences and course credit consequences for students. Using anonymized student-level data from the 2020-21 and 2021-22 school years (N=65,651), the study explores variations in policy implementation across districts and investigates the relationship between absences and course failures for freshmen. Our results highlight the wide variability in the number of allowed unexcused absences and the language of course credit consequence among districts. Additionally, our multivariate logistic regressions reveal FRL-eligible students more likely to fail a course after reaching their district’s unexcused absence threshold. Lastly, we find once students reach their district’s unexcused absence threshold, they more likely to fail a core course compared to a non-core course. Our findings provide insights into the variations of local policy implementation for student academic outcomes

Community acceptance and implementation of HIV prevention interventions for injection drug users

In 1997, the National Institutes of Health (NIH) reviewed evidence of the effectiveness of HIV prevention programs for injection drug users (IDUs) and recommended that three types ofinterventions be implemented to prevent transmission of HIV among IDUs: 1) community-based outreach, 2) expanded syringe access (including needle exchange programs [NEP] and pharmacy sales), and 3) drug treatment. Progress on increasing the acceptance and feasibility of implementing these programs has been made at the national level, but their implementation has been varied at the local level.Understanding the conditions under which communities accept and implement interventions can help guide effective strategies to foster the implementation of these interventions in areas where programs do not currently exist

Investigation of external refrigeration systems for long term cryogenic storage Final report

Data on external refrigeration systems for space storage of cryogens for long period

Investigation of external refrigeration systems for long-term cryogenic storage

Evaluation of cryogenic refrigeration systems for space application

Construction of networks with intrinsic temporal structure from UK cattle movement data.

BACKGROUND: The implementation of national systems for recording the movements of cattle between agricultural holdings in the UK has enabled the development and parameterisation of network-based models for disease spread. These data can be used to form a network in which each cattle-holding location is represented by a single node and links between nodes are formed if there is a movement of cattle between them in the time period selected. However, this approach loses information on the time sequence of events thus reducing the accuracy of model predictions. In this paper, we propose an alternative way of structuring the data which retains information on the sequence of events but which still enables analysis of the structure of the network. The fundamental feature of this network is that nodes are not individual cattle-holding locations but are instead direct movements between pairs of locations. Links are made between nodes when the second node is a subsequent movement from the location that received the first movement. RESULTS: Two networks are constructed assuming (i) a 7-day and (ii) a 14-day infectious period using British Cattle Movement Service (BCMS) data from 2004 and 2005. During this time period there were 4,183,670 movements that could be derived from the database. In both networks over 98% of the connected nodes formed a single giant weak component. Degree distributions show scale-free behaviour over a limited range only, due to the heterogeneity of locations: farms, markets, shows, abattoirs. Simulation of the spread of disease across the networks demonstrates that this approach to restructuring the data enables efficient comparison of the impact of transmission rates on disease spread. CONCLUSION: The redefinition of what constitutes a node has provided a means to simulate disease spread using all the information available in the BCMS database whilst providing a network that can be described analytically. This will enable the construction of generic networks with similar properties with which to assess the impact of small changes in network structure on disease dynamics.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

OCS Leasing and Auctions: Incentives and the Performance of Alternative Bidding Institutions

In Watt v. Energy Action Educational Foundation, the Supreme Court rebutted a challenge to the federal government\u27s mix of \u27nontraditional\u27 outer continental shelf lease-auction mechanisms authorized under the 1978 OCS Amendments. The issues of this case addressed here include: the economic intent of the congressional language; incentive properties of various of the authorized auction processes; methodological shortcomings inherent in the implicit congressional directive for field experimentation; and, the usefulness of laboratory experimental economics in answering relevant auction-policy questions. The discussion of experimental economics includes evidence already gained from laboratory experiments relating to hypotheses about auction-market performance