56 research outputs found

    FIBRE OPTICAL COUPLER SIMULATION BY COMSOL MULTIPHYSICS SOFTWARE

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    Funding: The research has been supported by the European Regional Development Fund project No.1.1.1.1/18/A/068. The Institute of Solid State Physics, University of Latvia as a Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.The paper presents a simulation model developed for a special optical coupler intended for coupling radiation from signal and pump sources used for the realization of cladding-pumped doped fibre amplifiers. The model is developed in COMSOL Multiphysics and used to assess the pumping efficiency for different side pumping angles and different numbers of electromagnetic modes. The obtained results show that the highest pumping efficiency, above 75 %, is achieved for 5–14 modes when two fibres representing the pump source and the signal source form a 10-degree angle between their central axes. The search for the optimal number of modes corresponds to the development trend in optical coupler technology where the multimode pumping by light-emitting diode (LED) replaces the classical scheme with a single-mode pumping by a laser diode (LD). © 2022 Sciendo. All rights reserved. --//-- This is an open access article Elsts E., Supe A., Spolitis S., Zakis K., Olonkins S., Udalcovs A., Murnieks R., Senkans U., Prigunovs D., Gegere L., Draguns K., Lukosevics I., Ozolins O., Grube J., Bobrovs V. FIBRE OPTICAL COUPLER SIMULATION BY COMSOL MULTIPHYSICS SOFTWARE (2022) Latvian Journal of Physics and Technical Sciences, 59 (5), pp. 3 - 14, DOI: 10.2478/lpts-2022-0036 published under the CC BY-NC-ND 4.0 licence.ERDF No.1.1.1.1/18/A/068; The Institute of Solid State Physics, University of Latvia as a Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2

    A rapid screening tool for psychological distress in children 3--6years old: results of a validation study.

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    International audienceABSTRACT: BACKGROUND: The mental health needs of young children in humanitarian contexts often remain unaddressed. The lack of a validated, rapid and simple tool for screening combined with few mental health professionals able to accurately diagnose and provide appropriate care mean that young children remain without care. Here, we present the results of the principle cross-cultural validation of the "Psychological Screening for Young Children aged 3 to 6" (PSYCAa3-6). The PSYCa 3--6 is a simple scale for children 3 to 6 years old administered by non-specialists, to screen young children in crises and thereby refer them to care if needed. METHODS: This study was conducted in Maradi, Niger. The scale was translated into Hausa, using corroboration of independent translations. A cross-cultural validation was implemented using quantitative and qualitative methods. A random sample of 580 mothers or caregivers of children 3 to 6 years old were included. The tool was psychometrically examined and diagnostic properties were assessed comparing the PSYCa 3--6 against a clinical interview as the gold standard. RESULTS: The PSYCa 3--6 Hausa version demonstrated good concurrent validity, as scores correlated with the gold standard and the Clinical Global Impression Severity Scale (CGI-S) [rho = 0.41, p-value = 0.00]. A reduction procedure was used to reduce the scale from 40 to 22 items. The test-retest reliability of the PSYCa 3--6 was found to be high (ICC 0.81, CI95% [0.68; 0.89]). In our sample, although not the purpose of this study, approximately 54 of 580 children required subsequent follow-up with a psychologist. CONCLUSIONS: To our knowledge, this is the first validation of a screening scale for children 3 to 6 years old with a cross-cultural validation component, for use in humanitarian contexts. The Hausa version of the PSYCa 3--6 is a reliable and a valuable screening tool for psychological distress. Further studies to replicate our findings and additional validations of the PSYCa 3--6 in other populations may help improve the delivery of mental health care to children

    Depression in multicultural Australia: Policies, research and services

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    BACKGROUND: Depression is one of the leading causes of disability in Australia. The cultural and linguistic diversity of the Australian population poses a significant challenge to health policy development, service provision, professional education, and research. The purpose of this study is to explore the extent to which the fact of cultural and linguistic diversity has influenced the formulation of mental health policy, the conduct of mental health research and the development of mental health services for people with depression from ethnic minority communities. METHODS: The methods used for the different components of the study included surveys and document-based content and thematic analyses. RESULTS: Policy is comprehensive but its translation into programs is inadequate. Across Australia, there were few specific programs on depression in ethnic minority communities and they are confronted with a variety of implementation difficulties. The scope and scale of research on depression in Ethnic minority communities is extremely limited. CONCLUSION: A key problem is that the research that is necessary to provide evidence for policy and service delivery is lacking. If depression in Ethnic minority communities is to be addressed effectively the gaps between policy intentions and policy implementation, and between information needs for policies and practice and the actual research that is being done, have to be narrowed

    A Five-Factor Theory Perspective

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    Abstract. Five-Factor Theory (FFT) is a conceptualization of the personality system that identifies traits as abstract Basic Tendencies rooted in biology. In this chapter, FFT is examined in relation to recent findings in cross-cultural psychology reported in this volume. FFT correctly predicts the universality of personality structure, maturation, and gender differentiation. FFT suggests that differences in the mean levels of traits across cultures may be due to differences in the distribution of trait-related alleles, and that cultural dif-ferences may be the effect, rather than the cause, of trait level differences. Reports of substantial cohort and acculturation effects pose challenges to FFT and provide special opportunities for future research

    Comparative-Study of Affective-Disorders in 3 Asian Countries .2. Differences in Prevalence Rates and Symptom Presentation

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    This study used standardized diagnostic criteria and method to investigate both prevalence rates and nature of symptoms of depressive disorders in three Asian centres - Nagasaki, Shanghai and Seoul. Of the patients who visited a psychiatric clinic in each of the 3 centres for the first time, over 20% suffered from depression. Unlike previous reported prevalence rates for Asian countries, these results suggest that rates in Asia may not be much lower than those reported in Western countries. Although prevalence rates of depression were similar in all 3 centres, differences in symptoms were noted
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