2,973 research outputs found

    Information Transfer Implies State Collapse

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    We attempt to clarify certain puzzles concerning state collapse and decoherence. In open quantum systems decoherence is shown to be a necessary consequence of the transfer of information to the outside; we prove an upper bound for the amount of coherence which can survive such a transfer. We claim that in large closed systems decoherence has never been observed, but we will show that it is usually harmless to assume its occurrence. An independent postulate of state collapse over and above Schroedinger's equation and the probability interpretation of quantum states, is shown to be redundant.Comment: 13 page

    Systematics of heavy-ion fusion hindrance at extreme sub-barrier energies

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    The recent discovery of hindrance in heavy-ion induced fusion reactions at extreme sub-barrier energies represents a challenge for theoretical models. Previously, it has been shown that in medium-heavy systems, the onset of fusion hindrance depends strongly on the "stiffness" of the nuclei in the entrance channel. In this work, we explore its dependence on the total mass and the QQ-value of the fusing systems and find that the fusion hindrance depends in a systematic way on the entrance channel properties over a wide range of systems.Comment: Submitted to Phys. Rev. Lett., 5 pages, 3 figure

    Effectiveness of highly active antiretroviral therapy in HIV-positive children: evaluation at 12 months in a routine program in Cambodia.

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    OBJECTIVE: Increasing access to highly active antiretroviral therapy to reach all those in need in developing countries (scale up) is slowly expanding to HIV-positive children, but documented experience remains limited. We aimed to describe the clinical, immunologic, and virologic outcomes of pediatric patients with >12 months of highly active antiretroviral therapy in 2 routine programs in Cambodia. METHODS: Between June 2003 and March 2005, 212 children who were younger than 13 years started highly active antiretroviral therapy. Most patients started a standard first-line regimen of lamivudine, stavudine, and nevirapine, using split adult fixed-dosage combinations. CD4 percentage and body weight were monitored routinely. A cross-sectional virologic analysis was conducted in January 2006; genotype resistance testing was performed for patients with a detectable viral load. RESULTS: Mean age of the subjects was 6 years. Median CD4 percentage at baseline was 6. Survival was 92% at 12 months and 91% at 24 months; 13 patients died, and 4 were lost to follow-up. A total of 81% of all patients had an undetectable viral load. Among the patients with a detectable viral load, most mutations were associated with resistance to lamivudine and non-nucleoside reverse-transcriptase inhibitor drugs. Five patients had developed extensive antiretroviral resistance. Being an orphan was found to be a predictor of virologic failure. CONCLUSIONS: This study provides additional evidence of the effectiveness of integrating HIV/AIDS care with highly active antiretroviral therapy for children in a routine setting, with good virologic suppression and immunologic recovery achieved by using split adult fixed-dosage combinations. Viral load monitoring and HIV genotyping are valuable tools for the clinical follow-up of the patients. Orphans should receive careful follow-up and extra support

    Enhanced transmission versus localization of a light pulse by a subwavelength metal slit: Can the pulse have both characteristics?

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    The existence of resonant enhanced transmission and collimation of light waves by subwavelength slits in metal films [for example, see T.W. Ebbesen et al., Nature (London) 391, 667 (1998) and H.J. Lezec et al., Science, 297, 820 (2002)] leads to the basic question: Can a light be enhanced and simultaneously localized in space and time by a subwavelength slit? To address this question, the spatial distribution of the energy flux of an ultrashort (femtosecond) wave-packet diffracted by a subwavelength (nanometer-size) slit was analyzed by using the conventional approach based on the Neerhoff and Mur solution of Maxwell's equations. The results show that a light can be enhanced by orders of magnitude and simultaneously localized in the near-field diffraction zone at the nm- and fs-scales. Possible applications in nanophotonics are discussed.Comment: 5 figure

    Psychometric properties of the Internalized Stigma of Mental Illness (ISMI-10) scale in a Dutch sample of employees with mental illness

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    BACKGROUND: Internalized stigma can have numerous negative effects on the well-being and employment of people with mental illness. Brief, valid, and reliable measures are needed to get a better understanding of self-stigmatization. The aim of this study is to translate the brief version of the Internalized Stigma of Mental Illness (ISMI-10) scale into a Dutch version and to assess the reliability and validity of this Dutch version in a sample of employees with mental illness. METHODS: The ISMI-10 was translated into Dutch using the forward-backward translation procedure. The sample consisted of 161 employees with mental illness. Internal consistency was evaluated and the retest reliability was tested with 68 respondents. The construct validity was evaluated by testing convergent and divergent validity. RESULTS: The Dutch ISMI-10 showed good internal consistency (α = 0.83) and good test-retest reliability (r = 0.73). The Dutch ISMI-10 demonstrated excellent convergent validity; high correlations were found between the Dutch ISMI-10 and hope (r = -0.54), anxiety and depression (r = 0.59), self-esteem (r = -0.56), and empowerment (r = − 0.59). Acceptable divergent validity was indicated; small correlations were found between the Dutch ISMI-10 and the physical functioning subscale (r = -0.27) and the role limitation due to physical problems subscale (r = -0.21), and medium correlations were found between the Dutch ISMI-10 and the general health subscale (r = -0.36). CONCLUSION: The Dutch ISMI-10 demonstrated adequate psychometric properties for assessing internalized stigma and can be used by researchers in Dutch speaking countries to get a better understanding of self-stigmatization among people with mental illness. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-022-04284-5

    Effectiveness of a stigma awareness intervention on reemployment of people with mental health issues/mental illness:A cluster randomised controlled trial

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    PurposeA barrier for reemployment of people with mental health issues/mental illness (MHI) is workplace stigma and discrimination. In this RCT the effectiveness of a stigma-awareness intervention addressing finding work, retaining work and decisional stress were evaluated.MethodsA cluster RCT was conducted in 8 Dutch municipal practices. Randomisation took place at practice level. Participants were unemployed people with MHI, receiving social benefits. The intervention consisted of a decision aid for workplace disclosure for participants and a 2 × 3 h stigma-awareness training for their employment specialists. Primary outcomes were measured at baseline, 3-, 6- and 12-months. Multilevel analyses, containing random intercepts of participants nested in organizations, were conducted to analyse the effects of the intervention.ResultsParticipants (N = 153) were randomized to an experimental (n = 76) or control group (n = 77). At six months, significantly more participants of the experimental group (51%) had found work compared to the control group (26%). At twelve months, significantly more participants of the experimental group (49%) had retained work compared to the control group (23%). Intention-to-treat analyses showed that randomization to the experimental group was associated with finding (OR(95%CI) = 7.78(1.33–45.53), p = 0.02) and retaining (OR(95%CI) = 12.15(2.81–52.63), p < 0.01) work more often at twelve months. Analyses showed that the experimental and control group did not differ in decisional stress.ConclusionsOur stigma awareness intervention was effective for finding and retaining work. As the percentage of people who found and retained work almost doubled, this suggests that on a societal level, a vast number of unemployed people could be reemployed with a relatively simple intervention.Trial RegistrationThe study was retrospectively registered at the Dutch Trial Register (TRN: NL7798, date: 04-06-2019)

    On radiative corrections for unpolarized electron proton elastic scattering

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    A statistical analysis of the elastic unpolarized electron proton scattering data shows that, at large momentum transfer, the size and the ϵ\epsilon dependence of the radiative corrections, as traditionally calculated and applied, may induce large correlations of the parameters of the Rosenbluth fit, which prevent a correct extraction of the electric proton form factor. Using the electron QED structure (radiation) function approach the cross section of elastic electron-proton scattering in leading and next-to leading approximations is calculated and expressed as a correction to the Born cross section, which is different for the electric and the magnetic contribution. When properly applied to the data, it may give the solution to the problem of the discrepancy of the polarized and unpolarized results on electron proton scattering.Comment: 11 pagex, 5 figure

    Expectations of mental illness disclosure outcomes in the work context:A cross-sectional study among Dutch workers

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    Purpose The decision whether to disclose mental illness at work can have important positive and negative consequences for sustainable employment and well-being. The aim of the study is (1) to examine workers’ expectations of outcomes of mental illness disclosure in the workplace and to evaluate their expectations regarding which factors are of influence on these outcomes, (2) to identify distinct subgroups of workers, and (3) to characterize these subgroups in terms of personal, sociodemographic, and work-related characteristics. Methods In this cross-sectional survey study, a sample of 1224 Dutch workers was used. Latent Class Analysis (LCA) was used to identify classes of workers based on expected workplace mental illness outcomes. A three-step approach LCA was chosen to investigate whether the classes differed in characteristics. Results The majority of workers expected predominantly positive outcomes of workplace mental illness disclosure (e.g., being able to be one’s authentic self; 82.4%), even though they simultaneously expected disclosure to lead to advancement-related discrimination (e.g., lower chances of contract renewal; or getting a promotion; 68.4% and 57%, respectively). Six distinct subgroups of workers were identified based on expected workplace mental illness disclosure outcomes: two positive classes (50.1%), two negative classes (33.3%), and two classes who indicated not to know what the outcomes would be (16.7%). Significant differences between the classes were found on personal experience, work-related association with mental illness, gender, educational level, and workplace atmosphere. Conclusion The disclosure process is complex, as most workers were optimistic (i.e., expected generally positive outcomes) whilst simultaneously expecting workplace discrimination. Subgroup differences in expectations regarding workplace mental illness disclosure outcomes were found

    Line managers' hiring intentions regarding people with mental health problems:A cross-sectional study on workplace stigma

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    Objectives Stigma may negatively affect line managers’ intention to hire people with mental health problems (MHP). This study aims to evaluate line managers’ knowledge and attitudes concerning job applicants with MHP, and to assess which factors are associated with the intention (not) to hire an applicant with MHP. Methods A sample of Dutch line managers (N=670) filled out a questionnaire on their knowledge, attitudes and experiences concerning applicants/employees with MHP. Descriptive analyses and multiple regression analyses were used. Results The majority (64%) was reluctant to hire a job applicant with MHP, despite the fact that only 7% had negative and 52% had positive personal experiences with such employees. Thirty per cent were reluctant to hire an applicant if they knew the applicant had past MHP. Associated with higher reluctance to hire an applicant with MHP were the concerns that it will lead to long-term sickness absence (β (95% CI)=0.39 (0.23 to 0.55)), that the employee cannot handle the work (β (95% CI)=0.16 (0.00 to 0.33)) that one cannot count on the employee (β (95% CI)=0.41 (0.23 to 0.58)) and higher manager education level (β (95% CI)=0.25 (0.05 to 0.44)). Conversely, associated with positive hiring intentions was being in favour of diversity and/or inclusive enterprise (β(95% CI)=−0.64 (−0.87 to −0.41)). Conclusions As the majority of managers were reluctant to hire applicants with MHP, and even 30% were reluctant to hire applicants who had past MHP, these findings have major implications for social inclusion in the Netherlands, where about 75% of employees would disclose MHP at work

    High-Sensitivity Measurement of 3He-4He Isotopic Ratios for Ultracold Neutron Experiments

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    Research efforts ranging from studies of solid helium to searches for a neutron electric dipole moment require isotopically purified helium with a ratio of 3He to 4He at levels below that which can be measured using traditional mass spectroscopy techniques. We demonstrate an approach to such a measurement using accelerator mass spectroscopy, reaching the 10e-14 level of sensitivity, several orders of magnitude more sensitive than other techniques. Measurements of 3He/4He in samples relevant to the measurement of the neutron lifetime indicate the need for substantial corrections. We also argue that there is a clear path forward to sensitivity increases of at least another order of magnitude.Comment: 11 pages, 10 figure
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