4,524 research outputs found

    Students and Retirement Saving Predictors

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    Over the past century Americans have significantly increased personal income yet decreased personal savings. The researchers in this study examine college students habits and beliefs concerning saving for retirement. To our knowledge there is no published data about retirement savings among Americans in this age group. We try to determine whether a student\u27s retirement savings beliefs and habits can be predicted. We designed a model examining the student\u27s risk-aversion level, financial background, general savings habits, financial literacy and attitudes toward saving. We found that our overall model is predictive of a student\u27s beliefs and habits in regards to saving for retirement. In addition, the student\u27s level of risk-aversion, savings beliefs, and financial literacy were each independently predictive. The findings imply that students should be targeted if we would like to increase the personal savings rate in America. Financial literacy is the key and a personal finance course should be required to help students become aware of the saving options available and the power of saving early

    Effect of strain on aluminum nitride/gallium nitride Distributed Bragg Reflectors

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    III - N Distributed Bragg Reflectors (DBRs) are important components to nitride based optoelectronic devices. Nitride based DBRs are critical to the operation and performance of both Vertical Cavity Surface Emitting Lasers (VCSELs) and Light Emitting Diodes (LEDs). Aluminum Nitride (AlN)/Gallium Nitride DBRs are of particular interest because their high refractive index contrast allows the fabrication of DBRs with high reflectivity using a relatively low number of periods.;The growth of high quality AlN/GaN DBRs has been held back because of tensile strain resulting from the 2.4% lattice mismatch between AlN and GaN. This tensile strain has led to cracking in DBRs and has significantly decreased their overall reflectivity. Reducing this strain and subsequent cracking is critical to improving AlN/GaN DBR reflectivity and the overall efficiency of nitride based optoelectronic devices.;This work will focus on the characterization, simulation, and development of AlN/GaN DBRs. Individual AlN and GaN thin films will be characterized to determine their properties and promise for development DBR structures. AlN/GaN DBR structures will then be characterized and simulated to determine their overall performance. Finally, the effect of strain on both the apparent refractive index of individual layers and the overall performance of AlN/GaN DBRs will be investigated

    VALUING WATER QUALITY MONITORING: A CONTINGENT VALUATION EXPERIMENT INVOLVING HYPOTHETICAL AND REAL PAYMENTS

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    This paper studies the preferences and willingness-to-pay for individuals for volunteer water quality monitoring programs. The study involves supporting water quality monitoring at two ponds in the state of Rhode Island. The paper uses both a hypothetical and a real-payment contingent valuation survey to directly measure individual preferences and willingness-to-pay (WTP) for volunteer water quality monitoring at the two ponds. The overall results of the study suggest that hypothetical WTP is not statistically greater than real WTP, and that the average survey respondent is willing to support water quality monitoring on one of the two ponds. The study also finds that the specified purpose of water quality monitoring and certain socioeconomic characteristics of a respondent significantly affect the respondent's decision to support volunteer water quality monitoring.Environmental Economics and Policy,

    Memory B cells and CD8⁺ lymphocytes do not control seasonal influenza A virus replication after homologous re-challenge of rhesus macaques.

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    This study sought to define the role of memory lymphocytes in the protection from homologous influenza A virus re-challenge in rhesus macaques. Depleting monoclonal antibodies (mAb) were administered to the animals prior to their second experimental inoculation with a human seasonal influenza A virus strain. Treatment with either anti-CD8α or anti-CD20 mAbs prior to re-challenge had minimal effect on influenza A virus replication. Thus, in non-human primates with pre-existing anti-influenza A antibodies, memory B cells and CD8α⁺ T cells do not contribute to the control of virus replication after re-challenge with a homologous strain of influenza A virus

    Infection with host-range mutant adenovirus 5 suppresses innate immunity and induces systemic CD4+ T cell activation in rhesus macaques.

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    Ad5 is a common cause of respiratory disease and an occasional cause of gastroenteritis and conjunctivitis, and seroconversion before adolescence is common in humans. To gain some insight into how Ad5 infection affects the immune system of rhesus macaques (RM) 18 RM were infected with a host-range mutant Ad5 (Ad5hr) by 3 mucosal inoculations. There was a delay of 2 to 6 weeks after the first inoculation before plasmacytoid dendritic cell (pDC) frequency and function increased in peripheral blood. Primary Ad5hr infection suppressed IFN-γ mRNA expression, but the second Ad5hr exposure induced a rapid increase in IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC). Primary Ad5hr infection suppressed CCL20, TNF and IL-1 mRNA expression in PBMC, and subsequent virus exposures further dampened expression of these pro-inflammatory cytokines. Primary, but not secondary, Ad5hr inoculation increased the frequency of CXCR3+ CD4+ T cells in blood, while secondary, but not primary, Ad5hr infection transiently increased the frequencies of Ki67+, HLADR+ and CD95+/CCR5+ CD4+ T cells in blood. Ad5hr infection induced polyfunctional CD4 and CD8+ T cells specific for the Ad5 hexon protein in all of the animals. Thus, infection with Ad5hr induced a complex pattern of innate and adaptive immunity in RM that included transient systemic CD4+ T cell activation and suppressed innate immunity on re-exposure to the virus. The complex effects of adenovirus infection on the immune system may help to explain the unexpected results of testing Ad5 vector expressing HIV antigens in Ad5 seropositive people

    Facet-sparing lumbar decompression with a minimally invasive flexible MicroBlade Shaver® versus traditional decompression: quantitative radiographic assessment.

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    BackgroundLaminectomy/laminotomy and foraminotomy are well established surgical techniques for treatment of symptomatic lumbar spinal stenosis. However, these procedures have significant limitations, including limited access to lateral and foraminal compression and postoperative instability. The purpose of this cadaver study was to compare bone, ligament, and soft tissue morphology following lumbar decompression using a minimally invasive MicroBlade Shaver® instrument versus hemilaminotomy with foraminotomy (HL).MethodsThe iO-Flex® system utilizes a flexible over-the-wire MicroBlade Shaver instrument designed for facet-sparing, minimally invasive "inside-out" decompression of the lumbar spine. Unilateral decompression was performed at 36 levels in nine human cadaver specimens, six with age-appropriate degenerative changes and three with radiographically confirmed multilevel stenosis. The iO-Flex system was utilized on alternating sides from L2/3 to L5/S1, and HL was performed on the opposite side at each level by the same investigator. Spinal canal, facet joint, lateral recess, and foraminal morphology were assessed using computed tomography.ResultsSimilar increases in soft tissue canal area and decreases in ligamentum flavum area were noted in nondiseased specimens, although HL required removal of 83% more laminar area (P < 0.01) and 95% more bone resection, including the pars interarticularis and facet joints (P < 0.001), compared with the iO-Flex system. Similar increases in lateral recess diameter were noted in nondiseased specimens using each procedure. In stenotic specimens, the increase in lateral recess diameter was significantly (P = 0.02) greater following use of the iO-Flex system (43%) versus HL (7%). The iO-Flex system resulted in greater facet joint preservation in nondiseased and stenotic specimens. In stenotic specimens, the iO-Flex system resulted in a significantly greater increase in foraminal width compared with HL (24% versus 4%, P = 0.01), with facet joint preservation.ConclusionThe iO-Flex system resulted in significantly better decompression of the lateral recess and foraminal areas compared with HL, while preserving posterior spinal elements, including the facet joint

    Long-term effect of antiepileptic drug switch on serum lipids and C-reactive protein.

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    BACKGROUND: Prior studies have shown that switching patients from inducing antiepileptic drugs (AEDs) to lamotrigine, levetiracetam, or topiramate reduces serum lipids and C-reactive protein (CRP). These studies were all of short duration, and some drugs, such as zonisamide, have not been investigated. METHODS: We recruited 41 patients taking phenytoin or carbamazepine who were being switched to zonisamide, lamotrigine, or levetiracetam. We measured serum lipids and CRP before the switch, \u3e6weeks after, and \u3e6months after. An untreated control group (n=14) underwent similar measurement. We combined these data with those of our previous investigation (n=34 patients and 16 controls) of a very similar design. RESULTS: There were no differences in outcome measures between the two inducing AEDs nor among the three noninducing AEDs. Total cholesterol (TC), atherogenic lipids, and CRP were higher under inducer treatment than in controls. All measures were elevated under inducer treatment relative to noninducer treatment, including TC (24mg/dL higher, 95% CI: 17.5-29.9, p CONCLUSIONS: We demonstrate that switching from inducing to noninducing AEDs produces an enduring reduction in serum lipids and CRP. These results provide further evidence that inducing AEDs may be associated with elevated vascular disease risk. These are the first vascular risk marker data in patients taking zonisamide, which shows a profile similar to that of other noninducing AEDs

    The internal consistency and validity of the Vaccination Attitudes Examination Scale: A replication study

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    Background: Vaccinations are important preventative health behaviors. The recently developed Vaccination Attitudes Examination Scale (VAX) aims to measure the reasons behind refusal/hesitancy regarding vaccinations.  Purpose: The aim of this replication study is to conduct an independent test of the newly developed VAX scale in the U.K. We tested: (a) internal consistency (Cronbach’s alpha); (b) convergent validity by assessing its relationships with beliefs about medication, medical mistrust and perceived sensitivity to medicines; and (c) construct validity by testing how well the VAX scale discriminated between vaccinators and nonvaccinators.  Methods: A sample of 243 UK adults completed the VAX scale, the Beliefs about Medicines Questionnaire (BMQ), the Perceived Sensitivity to Medicines Scale (PSM) and the Medical Mistrust Index (MMI), in addition to demographics of age, gender, education levels and social deprivation. Participants were asked: (a) if they received an influenza vaccination in the past year; and (b) if they had a young child, had they vaccinated their young child against influenza in the past year.  Results: The VAX: (a) demonstrated high internal consistency (α=0.92); (b) was positively correlated with medical mistrust, beliefs about medicines and less strongly correlated with perceived sensitivity to medicines; and (c) successfully differentiated parental influenza vaccinators from non-vaccinators.  Conclusion: The VAX demonstrated good internal consistency, convergent and construct validity in an independent UK sample. It appears to be a useful measure to help us understand the health beliefs that promote or deter vaccination behavior
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