353 research outputs found
Using Target Efficiency to Select Program Participants and Risk-Factor Models: An Application to Child Mental Health Interventions for Preventing Future Crime
Statistical risk factor models are often proposed for screening high-risk children to participate in early intervention programs. Recent contributions to the program evaluation literature demonstrate the need for incorporating judgments about relative importance of false positives versus false negatives in screening. This paper formalizes these judgments as commensurable economic costs and benefits and applies them to demonstrate an approach to participant selection motivated by the standard cost-benefit criterion of maximizing expected net benefits. Implications of this approach are explored using data from a mental health prevention trial. We illustrate the response of expected net benefits to the choice of a selection risk level, the sensitivity of the optimal selection risk level to per participant cost/benefit magnitudes, and the use of the target-efficiency approach for choosing among alternative risk-factor models. Several strategies that directly incorporate expected net benefit maximization as a criterion in the model estimation process are also examined.
Growth, feedlot performance and carcass characteristics of Karakas and crossbred lambs (F1) (Ile de France x Akkaraman (G1) x Karakas) under rural farm conditions in Turkey
In this study the possibilities of using the Ile de France x Akkaraman (G1) genotype (IDFAG1) in improving the growth performance and carcass characteristics of fat-tailed Karakas sheep raised in rural farm conditions in the Van Region of Eastern Anatolia, Turkey, were investigated. The aim was to obtain some preliminary results for future studies which will be designed to develop a genotype which has the ability to adapt to the region's conditions, has a high yield and quality meat, grows fast, has a high feed conversion ability and a thin fat tail. Growth and feedlot performances and carcass characteristics of Karakas (KAR) and crossbred (IDFAK) lambs obtained from the mating of IDFAG1 rams with Karakas ewes were evaluated. A total of 97 KAR and IDFAK lambs reared under farm conditions was evaluated for growth characteristics. For the evaluation of feedlot performance and carcass characteristics, 10 KAR and seven IDFAK single-born male lambs weaned at two months of age were subjected to a finishing diet for 70 days and slaughtered. Least squares means of the weights of KAR and IDFAK lambs at birth and at six months were 3.2 ± 0.08 and 3.5 ± 0.08 kg and 29.6 ± 1.24 and 30.2 ± 1.41 kg, respectively. The means of untailed cold carcass weight and untailed dressing percentage of KAR and IDFAK lambs were 13.2 ± 0.39 and 14.3 ± 1.10 kg and 39.7 ± 0.42 and 44.3 ± 1.10%, respectively. Although feed efficiency and many carcass characteristics did not differ between groups, the carcasses of the IDFAK lambs contained a higher percentage of intramuscular fat that is desirable for consumers in Eastern Anatolia. Encouraging results have been obtained to suggest that IDFAG1 rams could be used to improve the productivity of Karakas sheep. Nevertheless, more detailed and larger scale experiments are needed to confirm the results on growth and carcass characteristics of crossbred lambs under different farm conditions. South African Journal of Animal Science Vol. 34(4) 2004: 223- 23
Implications of Middle School Behavior Problems for High School Graduation and Employment Outcomes of Young Adults: Estimation of a Recursive Model
The potentially serious adverse impacts of behavior problems during adolescence on employment outcomes in adulthood provide a key economic rationale for early intervention programs. However, the extent to which lower educational attainment accounts for the total impact of adolescent behavior problems on later employment remains unclear As an initial step in exploring this issue, we specify and estimate a recursive bivariate probit model that 1) relates middle school behavior problems to high school graduation and 2) models later employment in young adulthood as a function of these behavior problems and of high school graduation. Our model thus allows for both a direct effect of behavior problems on later employment as well as an indirect effect that operates via graduation from high school. Our empirical results, based on analysis of data from the NELS, suggest that the direct effects of externalizing behavior problems on later employment are not significant but that these problems have important indirect effects operating through high school graduation.
Diabetic Foot Due to Anaphylactic Shock: A Case Report
Introduction: Diabetic foot is a clinical disorder, which is commonly seen in patients with diabetes mellitus. It is also the major cause of below knee amputation in the world. There are many underlying causes such as neuropathic, ischemic, and infectious causes for diabetic foot. Local or systemic complications may develop after snake bite.
Case Presentation: We reported a very rare case, involving a 78-year-old male admitted to the Emergency Department, who developed anaphylactic shock and diabetic foot after the snake bite.
Conclusions: Reviewing the literature, this is the second reported case of snake bite associated with diabetic foot
Shifting network tomography toward a practical goal
Boolean Inference makes it possible to observe the congestion status of end-to-end paths and infer, from that, the congestion status of individual network links. In principle, this can be a powerful monitoring tool, in scenarios where we want to monitor a network without having direct access to its links. We consider one such real scenario: a Tier-1 ISP operator wants to monitor the congestion status of its peers. We show that, in this scenario, Boolean Inference cannot be solved with enough accuracy to be useful; we do not attribute this to the limitations of particular algorithms, but to the fundamental difficulty of the Inference problem. Instead, we argue that the "right" problem to solve, in this context, is compute the probability that each set of links is congested (as opposed to try to infer which particular links were congested when). Even though solving this problem yields less information than provided by Boolean Inference, we show that this information is more useful in practice, because it can be obtained accurately under weaker assumptions than typically required by Inference algorithms and more challenging network conditions (link correlations, non-stationary network dynamics, sparse topologies). © 2011 ACM
A physical modeling-based study on the control mechanisms of Negative Poisson's ratio anchor cable on the stratified toppling deformation of anti-inclined slopes
Available online 9 January 2021With ongoing increases in excavation depth, the large-scale toppling instability failure of stratified anti-inclined slopes is gaining wide attention. To address the problem of controlling toppling deformation failure of antiinclined slopes with traditional small-deformation materials, this paper takes the results of existing studies on the extraordinary mechanical properties of engineering-scale Negative Poisson’s ratio (NPR) anchor cable as a theoretical basis, and develops a model-scale NPR anchor cable according to similarity theory. Relying on a selfdeveloped “engineering disaster model experimental system”, a physical modeling-based experiment to explore the reinforcement mechanism of stratified anti-inclined slope using model-scale NPR and ordinary anchor cables is performed. The physical model is monitored using static strain data acquisition equipment, an infrared thermal imager, tension sensors, and digital speckle correlation method (DSCM) displacement field measurement equipment. The evolution of the displacement field, strain field, temperature field, and anchor cable force are obtained during excavation on the physical model. By comparing the evolution of these parameters with images from both the anti-inclined slope model instability failure test and the deformation characteristics on the two sides of the slope, which were reinforced using different types of anchor cables, this paper determines the mechanisms governing instability failure of anti-inclined slopes reinforced with NPR anchor cable. In addition, this paper also proves that NPR anchor cable can be used to monitor the sliding force of anti-inclined slopes throughout excavation, and lays a foundation for the application of NPR anchor cable monitoring technology to the advanced anti-inclined slope failure warning.Zhigang Tao, Chun Zhu, Manchao He, Murat Karaku
Oxygen and temperature sensitivity of blue to green to yellow light-emitting Pt(II) complexes
The synthesis and photophysical properties of a series of yellow-green to blue-green emitting heteroleptic, cyclometalated Pt(II)(acac) complexes based on substituted phenylpyridine and tetrahydroquinoline ligands is reported. The luminescence intensities and lifetimes of these compounds were also studied in poly(styrene) films with respect to their responses to oxygen and temperature. Particularly, due to the insensitivity to oxygen quenching, these complexes are promising candidates as inert reference dyes in optical sensors. On the other hand, the Pt(II) complex with 2-(4-bromophenyl)-5,6,7,8-tetrahydroquinoline as C^N ligand, displays a strong temperature quenching effect. The distinct response to temperature was additionally calibrated after incorporation in poly(vinylidene chloride-co-acrylonitrile) serving as oxygen-blocking matrix copolymer. The resulting yellow-green-emitting temperature sensor signifies an interesting alternative to the available mostly red emitting temperature-sensitive probes
IFITM3 incorporation sensitizes influenza A virus to antibody-mediated neutralization
The disease severity of influenza is highly variable in humans, and one genetic determinant behind these differences is the IFITM3 gene. As an effector of the interferon response, IFITM3 potently blocks cytosolic entry of influenza A virus (IAV). Here, we reveal a novel level of inhibition by IFITM3 in vivo: We show that incorporation of IFITM3 into IAV particles competes with incorporation of viral hemagglutinin (HA). Decreased virion HA levels did not reduce infectivity, suggesting that high HA density on IAV virions may be an antagonistic strategy used by the virus to prevent direct inhibition. However, we found that IFITM3-mediated reduction in HA content sensitizes IAV to antibody-mediated neutralization. Mathematical modeling predicted that this effect decreases and delays peak IAV titers, and we show that, indeed, IFITM3-mediated sensitization of IAV to antibody-mediated neutralization impacts infection outcome in an in vivo mouse model. Overall, our data describe a previously unappreciated interplay between the innate effector IFITM3 and the adaptive immune response
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Compressive Creep Performance and High Temperature Dimensional Stability of Conventional Silica Refractories
Furnace designers and refractory engineers recognize that optimized furnace superstructure design and refractory selection are needed as glass production furnaces are continually striving toward greater output and efficiencies. Harsher operating conditions test refractories to the limit, while changing production technology (such as the conversion to oxy-fuel from traditional air-fuel firing) can alter the way the materials perform. Refractories for both oxy- and air-fuel fired furnace superstructures are subjected to high temperatures during service that may cause them to excessively creep or subside if the refractory material is not creep resistant, or if it is subjected to high stress, or both. Furnace designers can ensure that superstructure structural integrity is maintained if the creep behavior of the refractory material is well understood and well represented by appropriate engineering creep models. Several issues limit the abilities of furnace designers to (1) choose the optimum refractory for their applications, (2) optimize the engineering design, or (3) predict the service mechanical integrity of their furnace superstructures. Published engineering creep data are essentially non-existent for almost all commercially available refractories used for glass furnace superstructures. The limited data that do exist are supplied by the various refractory suppliers. Unfortunately, these suppliers generally have different ways of conducting their mechanical testing and they also interpret and report their data differently; this makes it hard for furnace designers to draw fair comparisons between competing grades of candidate refractories. Furthermore, the refractory supplier's data are often not available in a form that can be readily used for furnace design and for the prediction and design of long-term structural integrity of furnace superstructures. With the aim of providing such comparable data, the US DOE's Office of Industrial Technology and its Advanced Industrial Materials program is sponsoring work to conduct creep testing and analysis on refractories of interest to the glass industry. An earlier stage of the project involved identifying which refractories to test and this is described elsewhere. Conventional silica was one such identified refractory category, and the present report describes the creep behavior of this class of refractories. To portray a more complete understanding of how these refractories perform at service temperatures, their fundamental corrosion resistances, dimensional stabilities, and microstructure were characterized as well
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