To Screen or to Vaccinate? A Decision Analysis for Rubella Prevention on Campus

Abstract

Rubella is common among young adults. The most important consequences of rubella are fetal anomalies resulting from maternal rubella infection in early pregnancy. Health officials strongly advocate a mandatory rubella immunization policy for college students, leaving school officials the dilemma of deciding how to implement it.

To effectively prevent a rubella outbreak, a herd immunity of ≥ 95% is needed. This can be accomplished either by: 1) screening all students who do not provide a valid rubella immunization certificate and giving the vaccine to those with negative titers, or 2) vaccinating all of them without prior testing.

At the Medical College of Virginia (MCV), we have shifted our approach of rubella prevention from “screening first” to “vaccinating without prior testing.” We analyzed data from the past 6 years of our rubella prevention program and found that the latter approach was safe and simpler to administer. Decision analysis reveals that this approach can achieve an identical herd immunity of 99.45%, with a 45% cost savings compared to the “screening” approach. Threshold analysis indicates that unless the cost of the lab test is less than that of the vaccine, or the incidence of adverse reactions and associated treatment costs escalates 23 fold, the decision to vaccinate every student is still favored. We conclude that our decision to vaccinate without prior testing is a sound decision based on available data

“Intra-Blood-Brain-Barrier Synthesis of HTLV-III-Specific IgG in Patients with Neurologic Symptoms Associated with AIDS or AIDS-Related Complex,” LIONEL RESNICK, et al. Intra-blood-brain-barrier production of virus-specific antibody is good evidence of infection within the blood-brain barrier. Patients with the acquired immunodeficiency syndrome (AIDS) have an increased incidence of neurologic abnormalities—i.e., unexplained, diffuse encephalopathy manifested clinically as chronic progressive dementia. To define the role of human T-cell lymphotropic virus Type III (HTLV-III), the etiologic agent of AIDS, in the pathogenesis of neurologic dysfunction, we compared cerebrospinal fluid and serum from patients with neurologic symptoms associated with AIDS and the AIDS-related complex for the presence of antibodies directed agains HTLV-III. Antibodies directed against HTLV-III antigens were detected by four immunologic tests: a fixed-cell immunofluorescence assay, an enzyme-linked immunosorbent assay, immunoblots of viral lysates, and immunoprecipitation of cellular lysates. All patients were seropositive, and 22 of 23 (96 per cent) had HTLV-III-specific antibodies in their cerebrospinal fluid. Unique oligoclonal IgG synthesis within the blood-brain barrier was elevated. In eight of nine patients tested, the enzyme-linked immunosorbent assay showed that the percentage of HTLV-III-specific IgG in cerebrospinal fluid was higher than in serum, suggesting that HTLV-III infection of neurologic tissue occurs in the majority of patients with neurologic disease associated with AIDS or its related complex. (New England Journal of Medicine 1985;313:1498–504.)     

FIGURES OF HOPE AND THE FILMIC IMAGINARY OF JIANGHU IN CONTEMPORARY HONG KONG CINEMA

Through an extensive allegorical reading of films, this paper attempts to capture a certain cultural form of imagination in Hong Kong during the transitional period leading up to the historical handover of power in 1997. Dwelling on the world of signification conjured up through what I call the jianghu filmic imaginary,the analysis focuses on the ideological and utopian impulses registered in relation to a whole emotional complex of anxiety, bewilderment and despair in the works of some highly creative local filmmakers of the genre: Ching Siu-Tong, Ann Hui, Tsui Hark and Wong KarWai. The study draws theoretically from Castoriadis's notion of the social imaginary and Bloch's aesthetics of hope, to focus on the textual and contextual re-constructions of a number of very unconventional martial arts swordplay (wuxia) films made in Hong Kong in the last two decades: namely, Tsui's Butterfly Murders (1979), Hui's Romance of Book and Sword (1987), Ching/Tsui's Swordsman II (1992), and Wong's Ashes of Time (1994). By identifying the ideological and affective moments in the filmic imaginary,I want to trace what has been left in a ruined culture for utopian longings, and point to the presence/absence of ‘hope’ as the cultural imagination for an unknown and unknowable future (beyond 1997). It is my contention that an understanding of that peculiar form of popular imaginary at the unusual juncture of Hong Kong's history can begin with a critical attempt to cope with this subtle practice of hope, so as to recognize (or reject) it as mediation in the process of our collective cultural crisis, anticipation and identification.     

考虑公平关切的供应链契约与协调

供应链契约是影响供应链整体绩效的重要因素.在传统两阶段供应链中引入公平关切,研究了公平关切行为倾向对供应链契约与协调的影响.文中假设零售商是公平关切的,在此假设下展开行为运筹分析,分别探讨了零售商的公平关切行为倾向对批发价契约,收益共享契约和回购契约等协调性的影响,并用算例加以验证.最后,在此基础上提出并证明了一般性结论:零售商的公平关切不会改变供应链的协调状态.     

CEO Duality,Agency Costs,and Internal Capital Allocation Efficiency

This study examines the impact of CEO duality on firms’ internal capital allocation efficiency. We observe that when the CEO is also chair of the board, diversified firms make inefficient investments, as they allocate more capital to business segments with relatively low growth opportunities over segments with high growth opportunities. The adverse impact of CEO duality on investment efficiency prevails only among firms that face high agency problems, as captured by high free cash flows, staggered board structure and low board independence. Depending on the severity of the agency problem, CEO duality is associated with a decrease in industry‐adjusted investment in high‐growth segments of 1% to 2.1% over the following year, relative to that in low‐growth segments. However, CEOs’ equity‐based compensation curbs the negative effect of CEO duality on internal capital allocation efficiency. Overall, the findings of this study offer strong support for the agency theory and postulate the internal capital allocation policy as an important channel through which CEO duality lowers firm value in diversified firms.     

Approximations to Optimal k‐Unit Cycles for Single‐Gripper and Dual‐Gripper Robotic Cells

We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts using either single‐gripper or dual‐gripper robots. The objective is to find a cyclic sequence of robot moves that minimizes the long‐run average time to produce a part or, equivalently, maximizes the throughput. Obtaining an efficient algorithm for an optimum k‐unit cyclic solution (k ≥ 1) has been a longstanding open problem. For both single‐gripper and dual‐gripper cells, the approximation algorithms in this paper provide the best‐known performance guarantees (obtainable in polynomial time) for an optimal cyclic solution. We provide two algorithms that have a running time linear in the number of machines: for single‐gripper cells (respectively, dual‐gripper cells), the performance guarantee is 9/7 (respectively, 3/2). The domain considered is free‐pickup cells with constant intermachine travel time. Our structural analysis is an important step toward resolving the complexity status of finding an optimal cyclic solution in either a single‐gripper or a dual‐gripper cell. We also identify optimal cyclic solutions for a variety of special cases. Our analysis provides production managers valuable insights into the schedules that maximize productivity for both single‐gripper and dual‐gripper cells for any combination of processing requirements and physical parameters.     

外商直接投资及其影响因素——来自中国地域的面板因果关系分析

 利用中国1993-2005年29个省的面板数据,本文建立了一个系统动态的因果关系模型,检验了外商直接投资（FDI）与其他影响变量的关系,在所有影响FDI的变量中,我们重点检验了GDP、FDI、国内投资和基础设施的因果关系。结果显示短期内GDP可以吸引FDI的流入,而FDI对国内投资增长是有效的,FDI对GDP的作用是通过对国内投资影响而实现的。长期内,FDI对国内投资和经济增长有促进作用,而与基础设施没有直接的关系。     

PCB离子阱质量分析器

目提出了一种利用普通印刷线路板(Printed Circuit Boards,PCB)加工构造离子阱质量分析器的新方法。用该方法制造的PCB离子阱仅由四块PCB平板电极和两块不锈钢薄片电极构成,具有结构简单、加工容易和价格低廉等优点,非常适合制造成低成本的便携式质谱仪。初步实验结果表明,应用这种方法所建造的PCB离子阱质谱仪系统,可以获得优于400的质量分辨率和300Thomson以上的质量扫描范围。     

The Effects of Alcohol in Breast Milk on Infant Behavioral State and Mother‐Infant Feeding Interactions

The short‐term impact of infant exposure to alcohol in breast milk on mother‐infant interactions and infant arousal was examined. Fourteen mother‐infant dyads were tested on 2 occasions that consisted of an alcohol administration and a nonalcohol condition. Mother‐infant interactions during feeding were videotaped and coded for dyadic reciprocity, maternal noncontingency, and dyadic conflict. Infants were observed for 1 hr after receiving either plain breast milk or breast milk containing alcohol. Behavioral state, startles, and tremors were recorded every 30 sec. Mother‐infant interactions were characterized by higher noncontingency and dyadic conflict in the alcohol condition. After drinking breast milk containing alcohol, infants changed behavioral state more often, startled more, and spent less time in quiet sleep and more time in quiet alert and crying states. These findings suggest that exposure to breast milk containing alcohol may not have a sedating effect, as commonly believed.     

Changes in Subjective and Objective Measures of Economic Well-Being and Their Interrelationship among the Elderly in Singapore and Taiwan

Social Indicators Research -