| 1. |
- Alftan, Johan, et al.
(författare)
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Failure due to perforation in corrugated board boxes
- 2013
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Konferensbidrag (refereegranskat)abstract
- Corrugated board boxes are often used as secondary packaging to protect consumer goods during transport. In shelf ready packaging, the boxes are perforated so that the front and top of the box can be easily removed and the remainder of the box can be used to store and display the goods. The perforations however also make the box weaker and less efficient for protection. The balance between the require-ments is today found by trial and error, but could benefit from a more systematic approach. In this study, we started with one of the basic tests of corrugated board boxes, the box compression test. A reference box without perforation and three boxes with different perforation were tested. During the box compression test, a pressure sensitive film registered the distribution of load, an IR camera registered heat from dissipa-tive processes such as plasticity and fracture, and a displacement transducer was used to measure out-of-plane deflection of box panels. All boxes, independent of perforation, failed at similar compression forces, suggesting that the box compression test alone is not an adequate test for performance of the perforated boxes. It was however observed that the perforation did influence the failure of the boxes. The proximity to perforation affected where the panels failed. Analysis of displacement indicated that the perforations main-ly were loaded in compression or shear. During transport and handling, more severe loading situations for the perforations would occur which other tests can capture. Vibration tests can be used to study fatigue. Box compression tests with misaligned stacked boxes, loading of the whole box in other modes such as shear, or drop tests will all introduce complex loading were also tension and out-of-plane shear will occur. Climate tests can give effects similar to fatigue. Climate variations also has a large effect on creep.
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| 2. |
- Bonn, Stephanie E., et al.
(författare)
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Body mass index in relation to serum prostate-specific antigen levels and prostate cancer risk
- 2016
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Ingår i: International Journal of Cancer. - : WILEY-BLACKWELL. - 0020-7136 .- 1097-0215. ; 139:1, s. 50-57
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Tidskriftsartikel (refereegranskat)abstract
- High Body mass index (BMI) has been directly associated with risk of aggressive or fatal prostate cancer. One possible explanation may be an effect of BMI on serum levels of prostate-specific antigen (PSA). To study the association between BMI and serum PSA as well as prostate cancer risk, a large cohort of men without prostate cancer at baseline was followed prospectively for prostate cancer diagnoses until 2015. Serum PSA and BMI were assessed among 15,827 men at baseline in 2010-2012. During follow-up, 735 men were diagnosed with prostate cancer with 282 (38.4%) classified as high-grade cancers. Multivariable linear regression models and natural cubic linear regression splines were fitted for analyses of BMI and log-PSA. For risk analysis, Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) and natural cubic Cox regression splines producing standardized cancer-free probabilities were fitted. Results showed that baseline Serum PSA decreased by 1.6% (95% CI: -2.1 to -1.1) with every one unit increase in BMI. Statistically significant decreases of 3.7, 11.7 and 32.3% were seen for increasing BMI-categories of 25<30, 30<35 and 35 kg/m(2), respectively, compared to the reference (18.5<25 kg/m(2)). No statistically significant associations were seen between BMI and prostate cancer risk although results were indicative of a positive association to incidence rates of high-grade disease and an inverse association to incidence of low-grade disease. However, findings regarding risk are limited by the short follow-up time. In conclusion, BMI was inversely associated to PSA-levels. BMI should be taken into consideration when referring men to a prostate biopsy based on serum PSA-levels. What's new? High body mass index (BMI) has been associated with risk of aggressive or fatal prostate cancer. One possible explanation may be an effect on serum prostate-specific antigen (PSA) levels. Here, the authors assessed the association between BMI and serum PSA level and prostate cancer risk in a large prospective cohort study. While no statistically significant associations were found between BMI and overall risk of prostate cancer, increasing BMI was associated with decreased serum PSA levels among men with no previous prostate cancer diagnosis. BMI should be taken into consideration when referring men to a prostate biopsy based on PSA-test results.
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| 3. |
- Buli, Benti Geleta, et al.
(författare)
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Active Commuting and Healthy Behavior among Adolescents in Neighborhoods with Varying Socioeconomic Status : The NESLA Study
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 19:7
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Tidskriftsartikel (refereegranskat)abstract
- (1) Background: The World Health Organization recommends active commuting as a source of physical activity. Active commuting is determined by various factors, including the socioeconomic status (SES) of families and neighborhoods, distance to schools, perceived neighborhood safety, lifestyles, and availability of walkways and biking paths. This study aimed to assess factors associated with modes of transportation to and from school among adolescents aged 16–19 living in a middle-sized city in Sweden. (2) Method: Three hundred and fourteen students, of whom 55% were females, from schools in the city of Västerås participated in the study. Printed as well as web-based self-administered questionnaires were used to collect the data. (3) Results: Adolescents living in high SES neighborhoods were 80% more likely to bike or walk to school (OR = 1.80; CI: 1.01, 3.20) than adolescents living in low SES neighborhoods. Furthermore, active commuting was associated with higher consumption of fruits and vegetables (OR = 1.77; CI: 1.05, 2.97) and less consumption of junk foods (OR = 0.43; CI: 0.26, 0.71), as compared to passive commuting. (4) Conclusions: Active commuting is a cost-effective and sustainable source of regular physical activity and should be encouraged at a societal level.
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| 4. |
- Bälter, Katarina, et al.
(författare)
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Sustainable Lifestyle Among Office Workers (the SOFIA Study) : Protocol for a Cluster Randomized Controlled Trial
- 2024
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Ingår i: JMIR Research Protocols. - : JMIR Publications Inc.. - 1929-0748. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Society is facing multiple challenges, including lifestyle- and age-related diseases of major public health relevance, and this is of particular importance when the general population, as well as the workforce, is getting older. In addition, we are facing global climate change due to extensive emissions of greenhouse gases and negative environmental effects. A lifestyle that promotes healthy life choices as well as climate and environmentally friendly decisions is considered a sustainable lifestyle. Objective: This study aims to evaluate if providing information about a sustainable lifestyle encourages individuals to adopt more nutritious dietary habits and increase physical activity, as compared to receiving information solely centered around health-related recommendations for dietary intake and physical activity by the Nordic Nutrition Recommendations and the World Health Organization. Novel features of this study include the use of the workplace as an arena for health promotion, particularly among office workers—a group known to be often sedentary at work and making up 60% of all employees in Sweden. Methods: The Sustainable Office Intervention (SOFIA) study is a 2-arm, participant-blinded, cluster randomized controlled trial that includes a multilevel sustainable lifestyle arm (intervention arm, n=19) and a healthy lifestyle arm (control arm, n=14). The eligibility criteria were being aged 18-65 years and doing office work ≥20 hours per week. Both intervention arms are embedded in the theoretically based behavioral change wheel method. The intervention study runs for approximately 8 weeks and contains 6 workshops. The study focuses on individual behavior change as well as environmental and policy features at an organizational level to facilitate or hinder a sustainable lifestyle at work. Through implementing a citizen science methodology within the trial, the participants (citizen scientists) collect data using the Stanford Our Voice Discovery Tool app and are involved in analyzing the data, formulating a list of potential actions to bring about feasible changes in the workplace. Results: Participant recruitment and data collection began in August 2022. As of June 2024, a total of 37 participants have been recruited. The results of the pilot phase are expected to be published in 2024 or 2025. Conclusions: Given the ongoing climate change, negative environmental effects, and the global epidemic of metabolic diseases, a sustainable lifestyle among office workers holds important potential to help in counteracting this trend. Thus, there is an urgent unmet need to test the impact of a sustainable lifestyle on food intake, physical activity, and environmental and climate impacts in a worksite-based randomized controlled trial. This study protocol responds to a societal need by addressing multilevel aspects, including individual behavior changes as well as environmental and organizational changes of importance for the successful implementation of sustainable lifestyle habits in an office setting.
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| 5. |
- Corander, Jukka, et al.
(författare)
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Bayesian Block-Diagonal Predictive Classifier for Gaussian Data
- 2013
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Ingår i: Synergies of Soft Computing and Statistics for Intelligent Data Analysis. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642330414 - 9783642330421 ; , s. 543-551
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Bokkapitel (refereegranskat)abstract
- The paper presents a method for constructing Bayesian predictive classifier in a high-dimensional setting. Given that classes are represented by Gaussian distributions with block-structured covariance matrix, a closed form expression for the posterior predictive distribution of the data is established. Due to factorization of this distribution, the resulting Bayesian predictive and marginal classifier provides an efficient solution to the high-dimensional problem by splitting it into smaller tractable problems. In a simulation study we show that the suggested classifier outperforms several alternative algorithms such as linear discriminant analysis based on block-wise inverse covariance estimators and the shrunken centroids regularized discriminant analysis.
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| 6. |
- Ferreira, Manuel A R, et al.
(författare)
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Eleven loci with new reproducible genetic associations with allergic disease risk.
- 2019
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 143:2, s. 691-699
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A recent genome-wide association study (GWAS) identified 99 loci that contain genetic risk variants shared between asthma, hay fever, and eczema. Many more risk loci shared between these common allergic diseases remain to be discovered, which could point to new therapeutic opportunities.OBJECTIVE: We sought to identify novel risk loci shared between asthma, hay fever, and eczema by applying a gene-based test of association to results from a published GWAS that included data from 360,838 subjects.METHODS: We used approximate conditional analysis to adjust the results from the published GWAS for the effects of the top risk variants identified in that study. We then analyzed the adjusted GWAS results with the EUGENE gene-based approach, which combines evidence for association with disease risk across regulatory variants identified in different tissues. Novel gene-based associations were followed up in an independent sample of 233,898 subjects from the UK Biobank study.RESULTS: Of the 19,432 genes tested, 30 had a significant gene-based association at a Bonferroni-corrected P value of 2.5 × 10-6. Of these, 20 were also significantly associated (P < .05/30 = .0016) with disease risk in the replication sample, including 19 that were located in 11 loci not reported to contain allergy risk variants in previous GWASs. Among these were 9 genes with a known function that is directly relevant to allergic disease: FOSL2, VPRBP, IPCEF1, PRR5L, NCF4, APOBR, IL27, ATXN2L, and LAT. For 4 genes (eg, ATXN2L), a genetically determined decrease in gene expression was associated with decreased allergy risk, and therefore drugs that inhibit gene expression or function are predicted to ameliorate disease symptoms. The opposite directional effect was observed for 14 genes, including IL27, a cytokine known to suppress TH2 responses.CONCLUSION: Using a gene-based approach, we identified 11 risk loci for allergic disease that were not reported in previous GWASs. Functional studies that investigate the contribution of the 19 associated genes to the pathophysiology of allergic disease and assess their therapeutic potential are warranted.
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| 7. |
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| 8. |
- Halldner, Linda, et al.
(författare)
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Relative immaturity and ADHD : findings from nationwide registers, parent- and self-reports
- 2014
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Ingår i: Journal of Child Psychology and Psychiatry. - Stockholm : Wiley-Blackwell. - 0021-9630 .- 1469-7610. ; 55:8, s. 897-904
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment.METHODS: We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case-control designs to study 6-69 year-old individuals in Sweden from July 2005 to December 2009 (Cohort 1). Cohort 1 included 56,263 individuals diagnosed with ADHD or ever used prescribed ADHD-specific medication. Complementary population-representative cohorts provided DSM-IV ADHD symptom ratings; parent-reported for 10,760 9-year-old twins born 1995-2000 from the CATSS study (Cohort 2) and self-reported for 6,970 adult twins age 20-47 years born 1959-1970 from the STAGE study (Cohort 3). We calculated odds ratios (OR:s) for ADHD across age for individuals born in November/December compared to January/February (Cohort 1). ADHD symptoms in Cohorts 2 and 3 were studied as a function of calendar birth month.RESULTS: ADHD diagnoses and medication treatment were both significantly more common in individuals born in November/December versus January/February; peaking at ages 6 (OR: 1.8; 95% CI: 1.5-2.2) and 7 years (OR: 1.6; 95% CI: 1.3-1.8) in the Patient and Prescribed Drug Registers, respectively. We found no corresponding differences in parent- or self-reported ADHD symptoms by calendar birth month.CONCLUSION: Relative immaturity compared to class mates might contribute to ADHD diagnosis and pharmacotherapy despite absence of parallel findings in reported ADHD symptom loads by relative immaturity. Increased clinical awareness of this phenomenon may be warranted to decrease risk for imprecise diagnostics and treatment. We speculate that flexibility regarding age at school start according to individual maturity could reduce developmentally inappropriate demands on children and improve the precision of ADHD diagnostic practice and pharmacological treatment.
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| 9. |
- Halling Ullberg, Oskar, et al.
(författare)
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Workplace health promotion to facilitate physical activity among office workers in Sweden
- 2023
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Ingår i: Frontiers in Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Office workers spend most of their working time being sedentary, contributing to a sedentary lifestyle that increases the risk of developing disease and disability. A gradual decline in cardiorespiratory fitness among adults, along with increased rate of non-communicable diseases across developed countries, makes the workplace an important opportunity for promoting healthy behaviors. This study aimed to investigate: how office companies in Sweden organize and provide workplace health promotion services related to physical activity; the companies' vision for providing workplace health promotion; and potential facilitators and barriers. Nine informants from eight companies participated in the study, and both qualitative and quantitative data were collected by semi-structured interviews. Informants were selected through purposive sampling in collaboration with eight companies in the office market, including companies that own and develop office buildings, shared workspaces, interior design, sustainable solutions, or consult on issues related to the office sector. The framework method was used to analyze the data in a flexible and systematic way. The results showed that workplace health promotion is implemented to maintain employee health, productivity, and employee branding. Also, a significant number of financial resources, organizational support and office space are devoted to workplace health promotion. Convenience and easy access to storage and fitness facilities are key facilitators. In conclusion, this study highlights the importance of employees' engagement in developing and improving workplace health promotion and addressing work-life balance constraints that hinder a healthy lifestyle. Removing barriers on an organizational level may improve the usage of workplace health promotion related to physical activity among office employees.
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| 10. |
- Hedman, Anna, et al.
(författare)
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Bidirectional relationship between eating disorders and autoimmune diseases
- 2019
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Ingår i: Journal of Child Psychology and Psychiatry. - Stockholm : Blackwell Publishing. - 0021-9630 .- 1469-7610. ; 60:7, s. 803-812
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Immune system dysfunction may be associated with eating disorders (ED) and could have implications for detection, risk assessment, and treatment of both autoimmune diseases and EDs. However, questions regarding the nature of the relationship between these two disease entities remain. We evaluated the strength of associations for the bidirectional relationships between EDs and autoimmune diseases.METHODS: In this nationwide population-based study, Swedish registers were linked to establish a cohort of more than 2.5 million individuals born in Sweden between January 1, 1979 and December 31, 2005 and followed up until December 2013. Cox proportional hazard regression models were used to investigate: (a) subsequent risk of EDs in individuals with autoimmune diseases; and (b) subsequent risk of autoimmune diseases in individuals with EDs.RESULTS: We observed a strong, bidirectional relationship between the two illness classes indicating that diagnosis in one illness class increased the risk of the other. In women, the diagnoses of autoimmune disease increased subsequent hazards of anorexia nervosa (AN), bulimia nervosa (BN), and other eating disorders (OED). Similarly, AN, BN, and OED increased subsequent hazards of autoimmune diseases.Gastrointestinal-related autoimmune diseases such as, celiac disease and Crohn's disease showed a bidirectional relationship with AN and OED. Psoriasis showed a bidirectional relationship with OED. The previous occurence of type 1 diabetes increased the risk for AN, BN, and OED. In men, we did not observe a bidirectional pattern, but prior autoimmune arthritis increased the risk for OED.CONCLUSIONS: The interactions between EDs and autoimmune diseases support the previously reported associations. The bidirectional risk pattern observed in women suggests either a shared mechanism or a third mediating variable contributing to the association of these illnesses.
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| 11. |
- Lehtinen-Jacks, Susanna, et al.
(författare)
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Identifying office workers from self-reported information about occupationin a large population-based Swedish study (LifeGene)
- 2024
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Ingår i: 11th Nordic Conference of Epidemiology and Register-based Health Research(NordicEpi 2024).
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Konferensbidrag (refereegranskat)abstract
- Background: To enhance the usability of existing large population-based studies in epidemiologicresearch on office workers, we developed a procedure for a proxy variable on office worker in datawith open-ended responses on occupation.Methods: Self-reported open answers on occupation (n=3738) from the LifeGene pilot study werelinked to a modified version of the Swedish Standard Classification of Occupation 2012 (SSYK12). TheSSYK12 includes 8946 job titles with 4-digit codes which were categorized to managers, white-collarand blue-collar workers. Managers and white-collar workers were used as a proxy for office workers.We then used fuzzy string matching in R to calculate the Jaro-Winkler distance between the LifeGenepilot data answers on occupation and the modified SSYK12 job titles. Zero distance indicated aperfect match, whereas distances above zero were checked manually to assess various job titles asoffice worker or non-office worker. Thereafter, the resulting procedure was applied to the wholeLifeGene study with data on occupation (n=23 525).Results: We got perfect match against the modified SSYK12 job titles for 16 275 responses (69%) inthe large LifeGene data. Another 1721 responses (7%) matched occupations that we had manuallydefined as office worker or non-office worker in the pilot data set, and the remaining 5529 (24%)were unmatched. Among the matched occupations, 15 159 (84%) were office-workers, 2493 (14%)non-office workers, and 344 (2%) nondistinctive.Conclusion: The procedure for a proxy variable on office worker allowed us to classify three quartersof the open-ended responses on occupation.
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| 12. |
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| 13. |
- Liu, Bojing, et al.
(författare)
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Vagotomy and Parkinson disease : A Swedish register-based matched-cohort study
- 2017
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Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 88:21, s. 1996-2002
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To examine whether vagotomy decreases the risk of Parkinson disease (PD).Methods: Using data from nationwide Swedish registers, we conducted a matched-cohort study of 9,430 vagotomized patients (3,445 truncal and 5,978 selective) identified between 1970 and 2010 and 377,200 reference individuals from the general population individually matched to vagotomized patients by sex and year of birth with a 40: 1 ratio. Participants were followed up from the date of vagotomy until PD diagnosis, death, emigration out of Sweden, or December 31, 2010, whichever occurred first. Vagotomy and PD were identified from the Swedish Patient Register. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) using Cox models stratified by matching variables, adjusting for country of birth, chronic obstructive pulmonary disease, diabetes mellitus, vascular diseases, rheumatologic disease, osteoarthritis, and comorbidity index.Results: A total of 4,930 cases of incident PD were identified during 7.3 million person-years of follow-up. PD incidence (per 100,000 person-years) was 61.8 among vagotomized patients (80.4 for truncal and 55.1 for selective) and 67.5 among reference individuals. Overall, vagotomy was not associated with PD risk (HR 0.96, 95% CI 0.78-1.17). However, there was a suggestion of lower risk among patients with truncal vagotomy (HR 0.78, 95% CI 0.55-1.09), which may be driven by truncal vagotomy at least 5 years before PD diagnosis (HR 0.59, 95% CI 0.37-0.93). Selective vagotomy was not related to PD risk in any analyses.Conclusions: Although overall vagotomy was not associated the risk of PD, we found suggestive evidence for a potential protective effect of truncal, but not selective, vagotomy against PD development.
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| 14. |
- Pavlenko, Tatjana, et al.
(författare)
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Covariance structure approximation via glasso in high dimensional supervised classification
- 2012
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Ingår i: Journal of Applied Statistics. - : Informa UK Limited. - 0266-4763 .- 1360-0532. ; 39:8, s. 1643-1666
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Tidskriftsartikel (refereegranskat)abstract
- Recent work has shown that the Lasso-based regularization is very useful for estimating the high-dimensional inverse covariance matrix. A particularly useful scheme is based on penalizing the l(1) norm of the off-diagonal elements to encourage sparsity. We embed this type of regularization into high-dimensional classification. A two-stage estimation procedure is proposed which first recovers structural zeros of the inverse covariance matrix and then enforces block sparsity by moving non-zeros closer to the main diagonal. We show that the block-diagonal approximation of the inverse covariance matrix leads to an additive classifier, and demonstrate that accounting for the structure can yield better performance accuracy. Effect of the block size on classification is explored, and a class of as ymptotically equivalent structure approximations in a high-dimensional setting is specified. We suggest a variable selection at the block level and investigate properties of this procedure in growing dimension asymptotics. We present a consistency result on the feature selection procedure, establish asymptotic lower an upper bounds for the fraction of separative blocks and specify constraints under which the reliable classification with block-wise feature selection can be performed. The relevance and benefits of the proposed approach are illustrated on both simulated and real data.
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| 15. |
- Pavlenko, Tatjana, et al.
(författare)
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Detection of sparse and weak effects in high-dimensional feature space, with an application to microbiome data analysis
- 2020
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Ingår i: Recent Developments in Multivariate and Random Matrix Analysis. - Cham : Springer Nature. - 9783030567736 ; , s. 287-311
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- We present a family of goodness-of-fit (GOF) test statistics specifically designed for detection of sparse-weak mixtures, where only a small fraction of the observational units are contaminated arising from a different distribution. The test statistics are constructed as sup-functionals of weighted empirical processes where the weight functions employed are the Chibisov-O'Reilly functions of a Brownian bridge. The study recovers and extends a number of previously known results on sparse detection using a weighted GOF (wGOF) approach. In particular, the results obtained demonstrate the advantage of our approach over a common approach that utilizes a family of regularly varying weight functions. We show that the Chibisov-O'Reilly family has important advantages over better known approaches as it allows for optimally adaptive, fully data-driven test procedures. The theory is further developed to demonstrate that the entire family is a flexible device that adapts to many interesting situations of modern scientific practice where the number of observations stays fixed or grows very slowly while the number of automatically measured features grows dramatically and only a small fraction of these features are useful. Numerical studies are performed to investigate the finite sample properties of the theoretical results. We shown that the Chibisov-O'Reilly family compares favorably to related test statistics over a broad range of sparsity and weakness regimes for the Gaussian and high-dimensional Dirichlet types of sparse mixture. Finally, an example of human gut microbiome data set is presented to illustrate that the family of tests has found applications in real-life sparse signal detection problems where the sample size is small in relation to the features dimension.
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| 16. |
- Shen, Qiujin, et al.
(författare)
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Strong impact on plasma protein profiles by precentrifugation delay but not by repeated freeze-thaw cycles, as analyzed using multiplex proximity extension assays
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : WALTER DE GRUYTER GMBH. - 1434-6621 .- 1437-4331. ; 56:4, s. 582-594
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Tidskriftsartikel (refereegranskat)abstract
- Background: A number of factors regarding blood collection, handling and storage may affect sample quality. The purpose of this study was to assess the impact on plasma protein profiles by delayed centrifugation and plasma separation and multiple freeze-thaw cycles.Methods: Blood samples drawn from 16 healthy individuals were collected into ethylenediaminetetraacetic acid tubes and kept either at 4 degrees C or 22 degrees C for 1-36 h prior to centrifugation. Plasma samples prepared 1 h after venipuncture were also subjected to two to eight cycles of freezing at -80 degrees C and thawing at 22 degrees C. Multiplex proximity extension assay, an antibody-based protein assay, was used to investigate the influence on plasma proteins.Results: Up to 36 h delay before blood centrifugation resulted in significant increases of 16 and 40 out of 139 detectable proteins in samples kept at 4 degrees C or 22 degrees C, respectively. Some increases became noticeable after 8 h delay at 4 degrees C but already after 1 h at 22 degrees C. For samples stored at 4 degrees C, epidermal growth factor (EGF), NF-kappa-B essential modulator, SRC, interleukin 16 and CD6 increased the most, whereas the five most significantly increased proteins after storage at 22 degrees C were CD40 antigen ligand (CD40-L), EGF, platelet-derived growth factor subunit B, C-X-C motif chemokine ligand 5 and matrix metallopeptidase 1 (MMP1). Only matrix metallopeptidase 7 (MMP7) decreased significantly over time and only after storage at 22 degrees C. No protein levels were found to be significantly affected by up to eight freeze-thaw cycles.Conclusions: Plasma should be prepared from blood after a limited precentrifugation delay at a refrigerated temperature. By contrast, the influence by several freeze-thaw cycles on detectable protein levels in plasma was negligible.
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| 17. |
- Sieurin, Johanna, et al.
(författare)
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Occupational stress and risk for Parkinson's disease : A nationwide cohort study.
- 2018
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Ingår i: Movement Disorders. - : John Wiley & Sons Ltd. - 0885-3185 .- 1531-8257. ; 33:9, s. 1456-1464
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Stress has been suggested as a contributing factor in the etiology of Parkinson's Disease (PD), but epidemiological evidence is sparse.OBJECTIVE: The objective of this study was to explore the association between occupational stress according to the job demands-control model and the risk for PD.METHODS: We conducted a population-based cohort study with 2,544,748 Swedes born 1920 to 1950 who had an occupation reported in the population and housing censuses in 1980 or, if missing, in 1970. Job demands and control were measured using a job-exposure matrix. Incident PD cases were identified using Swedish national health registers from 1987 to 2010. Data were analyzed with Cox regression with age as the underlying time scale, adjusting for sex, education, and chronic obstructive pulmonary disease as a proxy for smoking.RESULTS: During a mean follow-up time of 21.3 years, 21,544 incident PD cases were identified. High demands were associated with increased PD risk among men, most evident in men with high education. High control was associated with increased PD risk among the low educated. This association was more pronounced in women. High-strain jobs (high demands and low control) was only associated with increased PDrisk among men with high education, whereas active jobs (high demands and high control) were associated with increased PD risk among men with low education.INTERPRETATION: High job demands appear to increase PD risk in men, especially in men with high education, whereas high job control increases PD risk among low educated, more strongly in women. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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| 18. |
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| 19. |
- Sjörs, Camilla, et al.
(författare)
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Adherence to dietary recommendations for Swedish adults across categories of greenhouse gas emissions from food
- 2017
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Ingår i: Public Health Nutrition. - : CAMBRIDGE UNIV PRESS. - 1368-9800 .- 1475-2727. ; 20:18, s. 3381-3393
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Tidskriftsartikel (refereegranskat)abstract
- Objective To explore associations between diet-related greenhouse gas emissions (GHGE), nutrient intakes and adherence to the Nordic Nutrition Recommendations among Swedish adults. Design Diet was assessed by 4d food records in the Swedish National Dietary Survey. GHGE was estimated by linking all foods to carbon dioxide equivalents, using data from life cycle assessment studies. Participants were categorized into quartiles of energy-adjusted GHGE and differences between GHGE groups regarding nutrient intakes and adherence to nutrient recommendations were explored. Setting Sweden. Subjects Women (n 840) and men (n 627) aged 18-80 years. Results Differences in nutrient intakes and adherence to nutrient recommendations between GHGE groups were generally small. The dietary intake of participants with the lowest emissions was more in line with recommendations regarding protein, carbohydrates, dietary fibre and vitamin D, but further from recommendations regarding added sugar, compared with the highest GHGE group. The overall adherence to recommendations was found to be better among participants with lower emissions compared with higher emissions. Among women, 27 % in the lowest GHGE group adhered to at least twenty-three recommendations compared with only 12 % in the highest emission group. For men, the corresponding figures were 17 and 10 %, respectively. Conclusions The study compared nutrient intakes as well as adherence to dietary recommendations for diets with different levels of GHGE from a national dietary survey. We found that participants with low-emission diets, despite higher intake of added sugar, adhered to a larger number of dietary recommendations than those with high emissions.
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| 20. |
- Söderlund, Carina, et al.
(författare)
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The outdoor office: a pilot study of environmental qualities, experiences of office workers, and work-related well-being
- 2023
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Ingår i: Frontiers in Psychology. - : FRONTIERS MEDIA SA. - 1664-1078. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Outdoor office work is an emerging aspect of the concept of 'new ways of working', but only sparse data are available about the environmental qualities of the outdoor office space, experiences of office workers, and work-related well-being of outdoor office work. Here, we present an exploratory pilot study on well-being and outdoor office work in a public urban space. An outdoor office was set up in the courtyard of a university campus, and the participants (n = 16) conducted office work outdoors for 30 min and thereafter participated in an eye-tracking session for 11-15 min (n = 8) and subsequently filled out surveys (n = 16). The eye tracker allowed the discovery of natural and built elements in the outdoor environment that caught the participants' visual attention, whereas the surveys assessed aspects of their subjective experiences of the outdoor office space (its visual and spatial qualities) and the work there. The results are presented as network graphs where correlations are shown regarding different aspects of office work outdoors. The results indicate that outdoor office work in a public urban space may promote work-related well-being in terms of positive outdoor office space experiences. Based on the findings, a preliminary set of outdoor office qualities is proposed. Those qualities relate to the legibility and imageability of the outdoor office space, its focal points, and depth/spaciousness, in addition to attributes of usability and environmental richness, including if the outdoor office space affords natural contact and supports activities, in addition to social and individual interactions and relations.
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| 21. |
- Tillander, Annika, 1971-
(författare)
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Classification models for high-dimensional data with sparsity patterns
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today's high-throughput data collection devices, e.g. spectrometers and gene chips, create information in abundance. However, this poses serious statistical challenges, as the number of features is usually much larger than the number of observed units. Further, in this high-dimensional setting, only a small fraction of the features are likely to be informative for any specific project. In this thesis, three different approaches to the two-class supervised classification in this high-dimensional, low sample setting are considered.There are classifiers that are known to mitigate the issues of high-dimensionality, e.g. distance-based classifiers such as Naive Bayes. However, these classifiers are often computationally intensive and therefore less time-consuming for discrete data. Hence, continuous features are often transformed into discrete features. In the first paper, a discretization algorithm suitable for high-dimensional data is suggested and compared with other discretization approaches. Further, the effect of discretization on misclassification probability in high-dimensional setting is evaluated. Linear classifiers are more stable which motivate adjusting the linear discriminant procedure to high-dimensional setting. In the second paper, a two-stage estimation procedure of the inverse covariance matrix, applying Lasso-based regularization and Cuthill-McKee ordering is suggested. The estimation gives a block-diagonal approximation of the covariance matrix which in turn leads to an additive classifier. In the third paper, an asymptotic framework that represents sparse and weak block models is derived and a technique for block-wise feature selection is proposed. Probabilistic classifiers have the advantage of providing the probability of membership in each class for new observations rather than simply assigning to a class. In the fourth paper, a method is developed for constructing a Bayesian predictive classifier. Given the block-diagonal covariance matrix, the resulting Bayesian predictive and marginal classifier provides an efficient solution to the high-dimensional problem by splitting it into smaller tractable problems.The relevance and benefits of the proposed methods are illustrated using both simulated and real data.
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| 22. |
- Tillander, Annika, 1971-
(författare)
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Effect of Data Discretization on the Classification Accuracy in a High-Dimensional Framework
- 2012
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Ingår i: International Journal of Intelligent Systems. - : Hindawi Limited. - 0884-8173 .- 1098-111X. ; 27:4, s. 355-374
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Tidskriftsartikel (refereegranskat)abstract
- We investigate discretization of continuous variables for classification problems in a high-dimensional framework. As the goal of classification is to correctly predict a class membership of an observation, we suggest a discretization method that optimizes the discretization procedure using the misclassification probability as a measure of the classification accuracy. Our method is compared to several other discretization methods as well as result for continuous data. To compare performance we consider three supervised classification methods, and to capture the effect of high dimensionality we investigate a number of feature variables for a fixed number of observations. Since discretization is a data transformation procedure, we also investigate how the dependence structure is affected by this. Our method performs well, and lower misclassification can be obtained in a high-dimensional framework for both simulated and real data if the continuous feature variables are first discretized. The dependence structure is well maintained for some discretization methods.
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| 23. |
- Tillander, Annika, 1971-
(författare)
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Empirical evaluation of sparse classification boundaries and HC-feature thresholding in high-dimensional data
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The analysis of high-throughput data commonly used in modern applications poses many statistical challenges, one of which is the selection of a small subset of features that are likely to be informative for a specific project. This issue is crucial for success of supervised classification in very high-dimensional setting with sparsity patterns. In this paper, we derive an asymptotic framework that represents sparse and weak blocks model and suggest a technique for block-wise feature selection by thresholding. Our procedure extends the standard Higher Criticism (HC) thresholding to the case where dependence structure underlying the data can be taken into account and is shown to be optimally adaptive, i. e. performs well without knowledge of the sparsity and weakness parameters. We empirically investigate the detection boundary of our HC procedure and performance properties of some estimators of sparsity parameter. The relevance and benefits of our approach in high-dimensional classification is demonstrated using both simulation and real data.
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| 24. |
- Yamada, Takayuki, et al.
(författare)
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Test for Mean Matrix in GMANOVA Model Under Heteroscedasticity and Non-Normality for High-Dimensional Data
- 2023
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Ingår i: THEORY OF PROBABILITY AND MATHEMATICAL STATISTICS. - : TARAS SHEVCHENKO NATL UNIV KYIV, FAC MECH & MATH. - 0094-9000. ; 109, s. 129-158
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Tidskriftsartikel (refereegranskat)abstract
- This paper develops a unified testing methodology for high-dimensional generalized multivariate analysis of variance (GMANOVA) models. We derive a test of the bilateral linear hypothesis on the mean matrix in a general scenario where the dimensions of the observed vector may exceed the sample size, design may be unbalanced, the population distribution may be non-normal and the underlying group covariance matrices may be unequal. The suggested methodology is suitable for many inferential problems, such as the one-way MANOVA test and the test for multivariate linear hypothesis on the mean in the polynomial growth curve model. As a key component of our test procedure, we propose a bias-corrected estimator of the Frobenius norm of the mean matrix. We derive null and non-null asymptotic distributions of the test statistic under a general high-dimensional asymptotic framework that allows the dimensionality to arbitrarily exceed the sample size of a group. The accuracy of the proposed test in a finite sample setting is investigated through simulations conducted for several high-dimensional scenarios and various underlying population distributions in combination with different within-group covariance structures. For a practical demonstration we consider a daily Canadian temperature dataset that exhibits group structure, and conclude that the interaction of latitude and longitude has no effect to predict the temperature.
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