180 research outputs found

    Point Source Extraction with MOPEX

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    MOPEX (MOsaicking and Point source EXtraction) is a package developed at the Spitzer Science Center for astronomical image processing. We report on the point source extraction capabilities of MOPEX. Point source extraction is implemented as a two step process: point source detection and profile fitting. Non-linear matched filtering of input images can be performed optionally to increase the signal-to-noise ratio and improve detection of faint point sources. Point Response Function (PRF) fitting of point sources produces the final point source list which includes the fluxes and improved positions of the point sources, along with other parameters characterizing the fit. Passive and active deblending allows for successful fitting of confused point sources. Aperture photometry can also be computed for every extracted point source for an unlimited number of aperture sizes. PRF is estimated directly from the input images. Implementation of efficient methods of background and noise estimation, and modified Simplex algorithm contribute to the computational efficiency of MOPEX. The package is implemented as a loosely connected set of perl scripts, where each script runs a number of modules written in C/C++. Input parameter setting is done through namelists, ASCII configuration files. We present applications of point source extraction to the mosaic images taken at 24 and 70 micron with the Multiband Imaging Photometer (MIPS) as part of the Spitzer extragalactic First Look Survey and to a Digital Sky Survey image. Completeness and reliability of point source extraction is computed using simulated data.Comment: 20 pages, 13 Postscript figures, accepted for publication in PAS

    Association of changes in lifestyle with changes in sleep difficulties: an analysis of 38 400 participants over a 16-year follow-up

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    Objectives: To investigate the association between changes in lifestyle risk factors and changes is sleep difficulties. Design: Longitudinal repeated measures cohort study. Setting: University and national institute of occupational health. Participants: Participants of the Finnish Public Sector study with information on sleep and lifestyle-related risk factors collected in five repeat surveys with 4‐year intervals from 2000 to 2017. The participants were those, who had responded at least twice and had a change in sleep difficulties (having sleep difficulties vs not) (142 969 observations from 38 400 respondents (mean age 45.5 (SD 9.2) years, 83% women). Primary and secondary outcome measures: Changes in sleep quality over time. Longitudinal fixed effects analysis, a method that accounts for time-invariant confounders by design, was used. Results: At first available response, sleep difficulties were experienced by 13 998 (36%) of the respondents. Respectively, the mean age was 44.3 (10.0) years, 7526 (20%) were obese, 13 487 (35%) reported low physical activity, 3338 (9%) extensively drinking and 6547 (17%) were smoking. Except for smoking, the changes in the studied modifiable risks were associated with changes in sleep difficulties. The ORs for having sleep difficulties were 1.41 (95% CI 1.35 to 1.48) for obesity, 1.10 (95% CI 1.06 to 1.13) for low physical activity and 1.43 (95% CI 1.35 to 1.51) for heavy drinking. For smoking, the association was negative with OR 0.81 (95% CI 0.76 to 0.86). Including all four modifiable risks into model changed the estimates only little. Conclusions: The results of this longitudinal study suggest that changes in sleep quality are interconnected with changes in lifestyle

    Internal consistency and factor structure of Jenkins Sleep Scale: cross-sectional cohort study among 80 000 adults

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    OBJECTIVES: To assess the internal consistency and construct validity of the Finnish translation of the Jenkins Sleep Scale (JSS) in a large healthy working-age population with diverse work characteristics. DESIGN: Survey-based cross-sectional cohort study. SETTING: Survey conducted by an institute of occupational health. PARTICIPANTS: Employees of 10 towns and 6 hospital districts. PRIMARY AND SECONDARY OUTCOME MEASURES: The internal consistency defined by a Cronbach's alpha. Exploratory and confirmatory factor analyses to evaluate the construct structure of the JSS. RESULTS: Of 81 136 respondents, 14 890 (18%) were men and 66 246 (82%) were women. Their average age was 52.1 (13.2) years. Of the respondents, 41 823 (52%) were sleeping 7 or less hours per night. The mean JSS total score was 6.4 (4.8) points. The JSS demonstrated high internal consistency with an alpha of 0.80 (lower 95% confidence limit 0.80). Exploratory factor analysis supported a one-factor solution with eigenvalue of 1.94. Confirmatory factor analysis showed that all four items were positively correlated with a single common factor explaining 44%-61% of common factor's variance. CONCLUSIONS: The Finnish translation of JSS was found to be a unidimensional scale with good internal consistency. As such, the scale may be recommended as a practicable questionnaire when studying sleep difficulties in a healthy working-age population

    Local authorities and the engagement of private actors in climate change adaptation

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    The local level and private actors play an important role in the implementation of climate change adaptation. The engagement of the private sector and citizens has received increasing attention in recent years. Local authorities' choice of policy instruments, the distribution of responsibilities and the benefits of adaptation as a public or a private good have a bearing on the involvement of private actors. Based on interviews and documents from Copenhagen and Helsinki, we analyse how public authorities' choices, to whom and how they shift responsibilities, can foster transformational, participatory or market-oriented elements of adaptation. The results indicate that local authorities play a dominant role in providing adaptation. Public authorities steer where the private sector and citizens are expected to take responsibilities. This mix of top-down steering, market mechanisms and citizen involvement might reduce the advantages that a shift of responsibilities towards private actors could provide for the handling of climate change adaptation

    Hierarchical clustering of a Finnish newspaper article collection with graded relevance assessments

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    Abstract Search facilitated with agglomerative hierarchical clustering methods was studied in a collection of Finnish newspaper articles (N = 53,893). To allow quick experiments, clustering was applied to a sample (N = 5,000) that was reduced with principal components analysis. The dendrograms were heuristically cut to find an optimal partition, whose clusters were compared with each of the 30 queries to retrieve the best-matching cluster. The fourlevel relevance assessment was collapsed into a binary one by (A) considering all the relevant and (B) only the highly relevant documents relevant, respectively. Single linkage (SL) was the worst method. It created many tiny clusters, and, consequently, searches enabled with it had high precision and low recall. The complete linkage (CL), average linkage (AL), and Ward's methods (WM) returned reasonably-sized clusters typically of 18-32 documents. Their recall (A: 27-52%, B: 50-82%) and precision (A: 83-90%, B: 18-21%) was higher than and comparable to those of the SL clusters, respectively. The AL and WM clustering had 1-8% better effectiveness than nearest neighbor searching (NN), and SL and CL were 1-9% less efficient that NN. However, the differences were statistically insignificant. When evaluated with the liberal assessment A, the results suggest that the AL and WM clustering offer better retrieval ability than NN. Assessment B renders the AL and WM clustering better than NN, when recall is considered more important than precision. The results imply that collections in the highly inflectional and agglutinative languages, such as Finnish, may be clustered as the collections in English, provided that documents are appropriately preprocessed

    The existential risk space of climate change

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    Climate change is widely recognized as a major risk to societies and natural ecosystems but the high end of the risk, i.e., where risks become existential, is poorly framed, defined, and analyzed in the scientific literature. This gap is at odds with the fundamental relevance of existential risks for humanity, and it also limits the ability of scientific communities to engage with emerging debates and narratives about the existential dimension of climate change that have recently gained considerable traction. This paper intends to address this gap by scoping and defining existential risks related to climate change. We first review the context of existential risks and climate change, drawing on research in fields on global catastrophic risks, and on key risks and the so-called Reasons for Concern in the reports of the Intergovernmental Panel on Climate Change. We also consider how existential risks are framed in the civil society climate movement as well as what can be learned in this respect from the COVID-19 crisis. To better frame existential risks in the context of climate change, we propose to define them as those risks that threaten the existence of a subject, where this subject can be an individual person, a community, or nation state or humanity. The threat to their existence is defined by two levels of severity: conditions that threaten (1) survival and (2) basic human needs. A third level, well-being, is commonly not part of the space of existential risks. Our definition covers a range of different scales, which leads us into further defining six analytical dimensions: physical and social processes involved, systems affected, magnitude, spatial scale, timing, and probability of occurrence. In conclusion, we suggest that a clearer and more precise definition and framing of existential risks of climate change such as we offer here facilitates scientific analysis as well societal and political discourse and action

    Internal consistency and factor structure of Jenkins Sleep Scale : cross-sectional cohort study among 80 000 adults

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    Objectives To assess the internal consistency and construct validity of the Finnish translation of the Jenkins Sleep Scale (JSS) in a large healthy working-age population with diverse work characteristics. Design Survey-based cross-sectional cohort study. Setting Survey conducted by an institute of occupational health. Participants Employees of 10 towns and 6 hospital districts. Primary and secondary outcome measures The internal consistency defined by a Cronbach's alpha. Exploratory and confirmatory factor analyses to evaluate the construct structure of the JSS. Results Of 81 136 respondents, 14 890 (18%) were men and 66 246 (82%) were women. Their average age was 52.1 (13.2) years. Of the respondents, 41 823 (52%) were sleeping 7 or less hours per night. The mean JSS total score was 6.4 (4.8) points. The JSS demonstrated high internal consistency with an alpha of 0.80 (lower 95% confidence limit 0.80). Exploratory factor analysis supported a one-factor solution with eigenvalue of 1.94. Confirmatory factor analysis showed that all four items were positively correlated with a single common factor explaining 44%-61% of common factor's variance. Conclusions The Finnish translation of JSS was found to be a unidimensional scale with good internal consistency. As such, the scale may be recommended as a practicable questionnaire when studying sleep difficulties in a healthy working-age population.Peer reviewe

    Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy

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    Background - Children with cerebral palsy (CP) have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk. Purpose - The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP. Methods- This study included 55 ambulatory children with CP [mean (SD) age 11.3 (0.2) yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS) levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio) and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (≥10 min bouts) were calculated. Results - Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01), sustained moderate-to-vigorous activity (β = 0.250, p<0.05) and total activity (β = 0.238, p<0.05) were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05). Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01), waist circumference (r2 = -0.560, p<0.001), waist-height ratio (r2 = -0.560, p<0.001) and systolic blood pressure (r2 = -0.306, p<0.05) after adjustment for age, sex and GMFCS level. Conclusions - Participation in physical activity, particularly at a vigorous intensity, is associated with high cardiorespiratory fitness in children with CP. Low cardiorespiratory fitness is associated with increased cardiometabolic risk

    Genetic variants and blood pressure in a population-based cohort: the cardiovascular risk in young Finns study

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    Clinical relevance of a genetic predisposition to elevated blood pressure was quantified during the transition from childhood to adulthood in a population-based Finnish cohort (N=2,357). Blood pressure was measured at baseline in 1980 (age 3–18 years) and in follow-ups in 1983, 1986, 2001 and 2007. Thirteen single nucleotide polymorphisms associated with blood pressure were genotyped and three genetic risk scores associated with systolic and diastolic blood pressure and their combination were derived for all participants. Effects of the genetic risk score were 0.47 mmHg for systolic and 0.53 mmHg for diastolic blood pressure (both p<0.01). The combination genetic risk score was associated with diastolic blood pressure from age 9 onwards (β=0.68 mmHg, p=0.015). Replications in 1194 participants of the Bogalusa Heart Study showed essentially similar results. The participants in the highest quintile of the combination genetic risk score had a 1.82-fold risk of hypertension in adulthood (p<0.0001) compared with the lowest quintile, independent of a family history of premature hypertension. These findings show that genetic variants are associated with preclinical blood pressure traits in childhood, individuals with several susceptibility alleles have on average a 0.5 mmHg higher blood pressure and this trajectory continues from childhood to adulthood

    Keinot edistää sää- ja ilmastoriskien hallintaa

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    ELASTINEN-tutkimushankkeessa selvitettiin sää- ja ilmastoriskien hallinnan tilaa Suomessa ja arvioitiin riskienhallintakeinoja sekä eri toimijoiden roolia. Lisäksi tarkasteltiin, miten riskienhallinnan kustannuksia ja hyötyjä arvioidaan sekä miten riskienhallinta voidaan kääntää liiketoiminnaksi. Yhteiskunnan toimivuuden ja turvallisuuden ylläpitäminen edellyttää aktiivista varautumista sään ääriilmiöihin. Hankkeen tulosten mukaan suomalaiset organisaatiot eivät usein arvioi sää- ja ilmastoriskejä systemaattisesti. Varautumisessa tulee ottaa huomioon, että ilmastonmuutos voi muuttaa sään ääri-ilmiöitä, niiden esiintymistiheyttä ja voimakkuutta. Näin varautuminen sään ääri ilmiöihin on myös osa sopeutumista ilmastonmuutokseen. ELASTINEN-hanke esittää kolme suositusta, joilla sää- ja ilmastoriskien hallintaa voitaisiin parantaa ja sopeutumistyötä tukea: 1) monipuolistetaan tiedon tuottoa ja käyttöä, 2) vahvistetaan yhteistyötä ja kehitetään toimintatapoja sekä 3) kehitetään palveluita ja liiketoimintamahdollisuuksia. Suositusten toteuttamiseksi esitetään toimenpide-ehdotuksia, minkä lisäksi on tunnistettu toimien toteuttajatahoja. Nykyistä monipuolisempi ja helpommin saatavilla oleva tieto parantaisi mahdollisuuksia arvioida ja hallita sää- ja ilmastoriskejä sekä kykyä sopeutua ilmastonmuutoksen vaikutuksiin. Suomessa tulisi myös arvioida säännöllisesti Suomen ulkopuolella tapahtuvia ilmastonmuutoksen vaikutuksia, jotka voivat heijastua Suomeen. Sää- ja ilmastoriskien hallintatoimia tulisi valita ja arvioida myös taloudellisen tehokkuuden näkökulmasta
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