| 1. |
- Hagg, S, et al.
(författare)
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Short telomere length is associated with impaired cognitive performance in European ancestry cohorts
- 2017
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Ingår i: Translational psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 7:4, s. e1100-
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Tidskriftsartikel (refereegranskat)abstract
- The association between telomere length (TL) dynamics on cognitive performance over the life-course is not well understood. This study meta-analyses observational and causal associations between TL and six cognitive traits, with stratifications on APOE genotype, in a Mendelian Randomization (MR) framework. Twelve European cohorts (N=17 052; mean age=59.2±8.8 years) provided results for associations between qPCR-measured TL (T/S-ratio scale) and general cognitive function, mini-mental state exam (MMSE), processing speed by digit symbol substitution test (DSST), visuospatial functioning, memory and executive functioning (STROOP). In addition, a genetic risk score (GRS) for TL including seven known genetic variants for TL was calculated, and used in associations with cognitive traits as outcomes in all cohorts. Observational analyses showed that longer telomeres were associated with better scores on DSST (β=0.051 per s.d.-increase of TL; 95% confidence interval (CI): 0.024, 0.077; P=0.0002), and MMSE (β=0.025; 95% CI: 0.002, 0.047; P=0.03), and faster STROOP (β=−0.053; 95% CI: −0.087, −0.018; P=0.003). Effects for DSST were stronger in APOE ɛ4 non-carriers (β=0.081; 95% CI: 0.045, 0.117; P=1.0 × 10−5), whereas carriers performed better in STROOP (β=−0.074; 95% CI: −0.140, −0.009; P=0.03). Causal associations were found for STROOP only (β=−0.598 per s.d.-increase of TL; 95% CI: −1.125, −0.072; P=0.026), with a larger effect in ɛ4-carriers (β=−0.699; 95% CI: −1.330, −0.069; P=0.03). Two-sample replication analyses using CHARGE summary statistics showed causal effects between TL and general cognitive function and DSST, but not with STROOP. In conclusion, we suggest causal effects from longer TL on better cognitive performance, where APOE ɛ4-carriers might be at differential risk.
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| 2. |
- Mishra, A, et al.
(författare)
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Diminishing benefits of urban living for children and adolescents' growth and development
- 2023
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
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Tidskriftsartikel (refereegranskat)abstract
- Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
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| 3. |
- Barber, R. M., et al.
(författare)
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Healthcare access and quality index based on mortality from causes amenable to personal health care in 195 countries and territories, 1990-2015 : A novel analysis from the global burden of disease study 2015
- 2017
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Ingår i: The Lancet. - : Lancet Publishing Group. - 0140-6736 .- 1474-547X. ; 390:10091, s. 231-266
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Tidskriftsartikel (refereegranskat)abstract
- Background National levels of personal health-care access and quality can be approximated by measuring mortality rates from causes that should not be fatal in the presence of effective medical care (ie, amenable mortality). Previous analyses of mortality amenable to health care only focused on high-income countries and faced several methodological challenges. In the present analysis, we use the highly standardised cause of death and risk factor estimates generated through the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) to improve and expand the quantification of personal health-care access and quality for 195 countries and territories from 1990 to 2015. Methods We mapped the most widely used list of causes amenable to personal health care developed by Nolte and McKee to 32 GBD causes. We accounted for variations in cause of death certification and misclassifications through the extensive data standardisation processes and redistribution algorithms developed for GBD. To isolate the effects of personal health-care access and quality, we risk-standardised cause-specific mortality rates for each geography-year by removing the joint effects of local environmental and behavioural risks, and adding back the global levels of risk exposure as estimated for GBD 2015. We employed principal component analysis to create a single, interpretable summary measure-the Healthcare Quality and Access (HAQ) Index-on a scale of 0 to 100. The HAQ Index showed strong convergence validity as compared with other health-system indicators, including health expenditure per capita (r=0·88), an index of 11 universal health coverage interventions (r=0·83), and human resources for health per 1000 (r=0·77). We used free disposal hull analysis with bootstrapping to produce a frontier based on the relationship between the HAQ Index and the Socio-demographic Index (SDI), a measure of overall development consisting of income per capita, average years of education, and total fertility rates. This frontier allowed us to better quantify the maximum levels of personal health-care access and quality achieved across the development spectrum, and pinpoint geographies where gaps between observed and potential levels have narrowed or widened over time. Findings Between 1990 and 2015, nearly all countries and territories saw their HAQ Index values improve; nonetheless, the difference between the highest and lowest observed HAQ Index was larger in 2015 than in 1990, ranging from 28·6 to 94·6. Of 195 geographies, 167 had statistically significant increases in HAQ Index levels since 1990, with South Korea, Turkey, Peru, China, and the Maldives recording among the largest gains by 2015. Performance on the HAQ Index and individual causes showed distinct patterns by region and level of development, yet substantial heterogeneities emerged for several causes, including cancers in highest-SDI countries; chronic kidney disease, diabetes, diarrhoeal diseases, and lower respiratory infections among middle-SDI countries; and measles and tetanus among lowest-SDI countries. While the global HAQ Index average rose from 40·7 (95% uncertainty interval, 39·0-42·8) in 1990 to 53·7 (52·2-55·4) in 2015, far less progress occurred in narrowing the gap between observed HAQ Index values and maximum levels achieved; at the global level, the difference between the observed and frontier HAQ Index only decreased from 21·2 in 1990 to 20·1 in 2015. If every country and territory had achieved the highest observed HAQ Index by their corresponding level of SDI, the global average would have been 73·8 in 2015. Several countries, particularly in eastern and western sub-Saharan Africa, reached HAQ Index values similar to or beyond their development levels, whereas others, namely in southern sub-Saharan Africa, the Middle East, and south Asia, lagged behind what geographies of similar development attained between 1990 and 2015. Interpretation This novel extension of the GBD Study shows the untapped potential for personal health-care access and quality improvement across the development spectrum. Amid substantive advances in personal health care at the national level, heterogeneous patterns for individual causes in given countries or territories suggest that few places have consistently achieved optimal health-care access and quality across health-system functions and therapeutic areas. This is especially evident in middle-SDI countries, many of which have recently undergone or are currently experiencing epidemiological transitions. The HAQ Index, if paired with other measures of health-system characteristics such as intervention coverage, could provide a robust avenue for tracking progress on universal health coverage and identifying local priorities for strengthening personal health-care quality and access throughout the world. Copyright © The Author(s). Published by Elsevier Ltd.
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| 4. |
- Mõttus, René, et al.
(författare)
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Comparability of self-reported conscientiousness across 21 countries
- 2012
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Ingår i: European Journal of Personality. - : SAGE Publications. - 1099-0984 .- 0890-2070. ; 26:3, s. 303-317
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Tidskriftsartikel (refereegranskat)abstract
- In cross-national studies, mean levels of self-reported phenomena are often not congruent with more objective criteria. One prominent explanation for such findings is that people make self-report judgements in relation to culture-specific standards (often called the reference group effect), thereby undermining the cross-cultural comparability of the judgements. We employed a simple method called anchoring vignettes in order to test whether people from 21 different countries have varying standards for Conscientiousness, a Big Five personality trait that has repeatedly shown unexpected nation-level relationships with external criteria. Participants rated their own Conscientiousness and that of 30 hypothetical persons portrayed in short vignettes. The latter type of ratings was expected to reveal individual differences in standards of Conscientiousness. The vignettes were rated relatively similarly in all countries, suggesting no substantial culture-related differences in standards for Conscientiousness. Controlling for the small differences in standards did not substantially change the rankings of countries on mean self-ratings or the predictive validities of these rankings for objective criteria. These findings are not consistent with mean self-rated Conscientiousness scores being influenced by culture-specific standards. The technique of anchoring vignettes can be used in various types of studies to assess the potentially confounding effects of reference levels.
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| 5. |
- Mõttus, René, et al.
(författare)
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The effect of response style on self-reported conscientiousness across 20 countries.
- 2012
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Ingår i: Personality & Social Psychology Bulletin. - : SAGE Publications. - 0146-1672 .- 1552-7433. ; 38:11, s. 1423-1436
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Tidskriftsartikel (refereegranskat)abstract
- Rankings of countries on mean levels of self-reported Conscientiousness continue to puzzle researchers. Based on the hypothesis that cross-cultural differences in the tendency to prefer extreme response categories of ordinal rating scales over moderate categories can influence the comparability of self-reports, this study investigated possible effects of response style on the mean levels of self-reported Conscientiousness in 22 samples from 20 countries. Extreme and neutral responding were estimated based on respondents’ ratings of 30 hypothetical people described in short vignettes. In the vignette ratings, clear cross-sample differences in extreme and neutral responding emerged. These responding style differences were correlated with mean self-reported Conscientiousness scores. Correcting self-reports for extreme and neutral responding changed sample rankings of Conscientiousness, as well as the predictive validities of these rankings for external criteria. The findings suggest that the puzzling country rankings of self-reported Conscientiousness may to some extent result from differences in response styles.
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| 6. |
- Andersson, Martin, 1981-
(författare)
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A bilevel approach to parameter tuning of optimization algorithms using evolutionary computing : Understanding optimization algorithms through optimization
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Most optimization problems found in the real world cannot be solved using analytical methods. For these types of difficult optimization problems, an alternative approach is needed. Metaheuristics are a category of optimization algorithms that do not guarantee that an optimal solution will be found, but instead search for the best solutions using some general heuristics. Metaheuristics have been shown to be effective at finding “good-enough” solutions to a wide variety of difficult problems. Most metaheuristics involve control parameters that can be used to modify how the heuristics perform its search. This is necessary because different problems may require different search strategies to be solved effectively. The control parameters allow for the optimization algorithm to be adapted to the problem at hand. It is, however, difficult to predict what the optimal control parameters are for any given problem. The problem of finding these optimal control parameter values is known as parameter tuning and is the main topic of this thesis. This thesis uses a bilevel optimization approach to solve parameter tuning problems. In this approach, the parameter tuning problem itself is formulated as an optimization problem and solved with an optimization algorithm. The parameter tuning problem formulated as a bilevel optimization problem is challenging because of nonlinear objective functions, interacting variables, multiple local optima, and noise. However, it is in precisely this kind of difficult optimization problem that evolutionary algorithms, which are a subclass of metaheuristics, have been shown to be effective. That is the motivation for using evolutionary algorithms for the upper-level optimization (i.e. tuning algorithm) of the bilevel optimization approach. Solving the parameter tuning problem using a bilevel optimization approach is also computationally expensive, since a complete optimization run has to be completed for every evaluation of a set of control parameter values. It is therefore important that the tuning algorithm be as efficient as possible, so that the parameter tuning problem can be solved to a satisfactory level with relatively few evaluations. Even so, bilevel optimization experiments can take a long time to run on a single computer. There is, however, considerable parallelization potential in the bilevel optimization approach, since many of the optimizations are independent of one another. This thesis has three primary aims: first, to present a bilevel optimization framework and software architecture for parallel parameter tuning; second, to use this framework and software architecture to evaluate and configure evolutionary algorithms as tuners and compare them with other parameter tuning methods; and, finally, to use parameter tuning experiments to gain new insights into and understanding of how optimization algorithms work and how they can used be to their maximum potential. The proposed framework and software architecture have been implemented and deployed in more than one hundred computers running many thousands of parameter tuning experiments for many millions of optimizations. This illustrates that this design and implementation approach can handle large parameter tuning experiments. Two types of evolutionary algorithms, i.e. differential evolution (DE) and a genetic algorithm (GA), have been evaluated as tuners against the parameter tuning algorithm irace. The as pects of algorithm configuration and noise handling for DE and the GA as related to the parameter tuning problem were also investigated. The results indicate that dynamic resampling strategies outperform static resampling strategies. It was also shown that the GA needs an explicit exploration and exploitation strategy in order not become stuck in local optima. The comparison with irace shows that both DE and the GA can significantly outperform it in a variety of different tuning problems.
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| 7. |
- DeWitt, Jamie C., et al.
(författare)
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Zürich II Statement on Per- and Polyfluoroalkyl Substances (PFASs) : Scientific and Regulatory Needs
- 2024
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Ingår i: Environmental Science and Technology Letters. - 2328-8930. ; 11:8, s. 786-797
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Forskningsöversikt (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFASs) are a class of synthetic organic chemicals of global concern. A group of 36 scientists and regulators from 18 countries held a hybrid workshop in 2022 in Zürich, Switzerland. The workshop, a sequel to a previous Zürich workshop held in 2017, deliberated on progress in the last five years and discussed further needs for cooperative scientific research and regulatory action on PFASs. This review reflects discussion and insights gained during and after this workshop and summarizes key signs of progress in science and policy, ongoing critical issues to be addressed, and possible ways forward. Some key take home messages include: 1) understanding of human health effects continues to develop dramatically, 2) regulatory guidelines continue to drop, 3) better understanding of emissions and contamination levels is needed in more parts of the world, 4) analytical methods, while improving, still only cover around 50 PFASs, and 5) discussions of how to group PFASs for regulation (including subgroupings) have gathered momentum with several jurisdictions proposing restricting a large proportion of PFAS uses. It was concluded that more multi-group exchanges are needed in the future and that there should be a greater diversity of participants at future workshops.
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| 8. |
- Haq, Muhibul, et al.
(författare)
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Bourdieusian and resource-based perspectives on ethnic minority microbusinesses : The construction of a culture-induced entrepreneurship model
- 2024
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Ingår i: Journal of small business management (Print). - 0047-2778 .- 1540-627X. ; 62:4, s. 1982-2015
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Tidskriftsartikel (refereegranskat)abstract
- In contemporary developed Western societies, structural discrimination often bars ethnic minorities from entering mainstream entrepreneurship and labor markets. Consequently, minorities engage in microentrepreneurship for economic survival and to retain their social identities. Yet despite the economic value of ethnic minority microbusinesses, little is known about the underlying forces that develop fundamental resources which shape their performance. Based on Bourdieu's forms of capital and the resource-based view of the firm, our study presents a novel culture-induced entrepreneurship model. This model explains how ethnic minority culture shapes the development of human capital resources and how these resources contribute to business performance in communities which are often characterized as "left behind." Our study challenges the dominant underdog discourse of (cultural) capital deficit among ethnic minority entrepreneurs.
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| 9. |
- Haq, M., et al.
(författare)
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Human capital resources creation and utilization in ethnic minority microbusinesses : The construction of a culture-induced entrepreneurship model
- 2024
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Ingår i: Journal of the International Council for Small Business. - : Routledge. - 2643-7015 .- 2643-7023. ; 5:2, s. 106-116
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Tidskriftsartikel (refereegranskat)abstract
- We explored and found that a set of key resources, that we call human capital resources, play an important role in ethnic minority microbusinesses in an ethnic majority social and economic space. We have also found that these key resources are developed and maintained within the coethnic niche economic space shaped by coethnic cultural value systems. Building on qualitative interview data and drawing on Bourdieu’s forms of capital and the resource-based view of the firm, our study presents a novel microentrepreneurship model that we call the culture-induced entrepreneurship model. Overall, our model provides insights into how ethnic minority culture informs the creation of a set of human capital resources and how these key resources contribute to business performance in regional ethnic minority microbusinesses. Our model also shows relationships between these key human capital resources. © 2023 International Council for Small Business.
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