Browsing by Subject "VARIABLES"

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  • Vanhatalo, Jarno; Hartmann, Marcelo; Veneranta, Lari (2020)
    Species distribution models (SDM) are a key tool in ecology, conservation and management of natural resources. Two key components of the state-of-the-art SDMs are the description for species distribution response along environmental covariates and the spatial random effect that captures deviations from the distribution patterns explained by environmental covariates. Joint species distribution models (JSDMs) additionally include interspecific correlations which have been shown to improve their descriptive and predictive performance compared to single species models. However, current JSDMs are restricted to hierarchical generalized linear modeling framework. Their limitation is that parametric models have trouble in explaining changes in abundance due, for example, highly non-linear physical tolerance limits which is particularly important when predicting species distribution in new areas or under scenarios of environmental change. On the other hand, semi-parametric response functions have been shown to improve the predictive performance of SDMs in these tasks in single species models. Here, we propose JSDMs where the responses to environmental covariates are modeled with additive multivariate Gaussian processes coded as linear models of coregionalization. These allow inference for wide range of functional forms and interspecific correlations between the responses. We propose also an efficient approach for inference with Laplace approximation and parameterization of the interspecific covariance matrices on the euclidean space. We demonstrate the benefits of our model with two small scale examples and one real world case study. We use cross-validation to compare the proposed model to analogous semi-parametric single species models and parametric single and joint species models in interpolation and extrapolation tasks. The proposed model outperforms the alternative models in all cases. We also show that the proposed model can be seen as an extension of the current state-of-the-art JSDMs to semi-parametric models.
  • Puurunen, Jenni; Ottka, Claudia; Salonen, Milla; Niskanen, Julia E.; Lohi, Hannes (2022)
    As an individual's metabolism reflects health and disease states well, metabolomics holds a vast potential in biomedical applications. However, normal physiological factors, such as age, can also influence metabolism, challenging the establishment of disease-specific metabolic aberrations. Here, we examined how physiological and diet-related factors drive variance in the metabolism of healthy pet dogs. We analysed 2068 serum samples using a canine nuclear magnetic resonance (NMR) spectroscopy-based metabolomics platform. With generalized linear models, we discovered that age, breed, sex, sterilization, diet type and fasting time significantly affected the canine metabolite profiles. Especially, breed and age caused considerable variation in the metabolite concentrations, and breeds with very different body conformations systematically differed in several lipid measurands. Our results enhance the understanding how normal physiological factors influence canine metabolism, aid accurate interpretation of the NMR results, and suggest the NMR platform might be applied in identifying aberrations in nutrient absorption and metabolism.
  • Luoma, Ville; Saarinen, Ninni; Wulder, Michael A.; White, Joanne C.; Vastaranta, Mikko; Holopainen, Markus; Hyyppä, Juha (2017)
    Forest resource information has a hierarchical structure: individual tree attributes are summed at the plot level and then in turn, plot-level estimates are used to derive stand or large-area estimates of forest resources. Due to this hierarchy, it is imperative that individual tree attributes are measured with accuracy and precision. With the widespread use of different measurement tools, it is also important to understand the expected degree of precision associated with these measurements. The most prevalent tree attributes measured in the field are tree species, stem diameter-at-breast-height (dbh), and tree height. For dbh and height, the most commonly used measuring devices are calipers and clinometers, respectively. The aim of our study was to characterize the precision of individual tree dbh and height measurements in boreal forest conditions when using calipers and clinometers. The data consisted of 319 sample trees at a study area in Evo, southern Finland. The sample trees were measured independently by four trained mensurationists. The standard deviation in tree dbh and height measurements was 0.3 cm (1.5%) and 0.5 m (2.9%), respectively. Precision was also assessed by tree species and tree size classes; however, there were no statistically significant differences between the mensurationists for dbh or height measurements. Our study offers insights into the expected precision of tree dbh and height as measured with the most commonly used devices. These results are important when using sample plot data in forest inventory applications, especially now, at a time when new tree attribute measurement techniques based on remote sensing are being developed and compared to the conventional caliper and clinometer measurements.
  • Zsebeházi, Gabriella; Mahó, Sándor István (2021)
    Land surface models with detailed urban parameterization schemes provide adequate tools to estimate the impact of climate change in cities, because they rely on the results of the regional climate model, while operating on km scale at low cost. In this paper, the SURFEX land surface model driven by the evaluation and control runs of ALADIN-Climate regional climate model is validated over Budapest from the aspect of urban impact on temperature. First, surface temperature of SURFEX with forcings from ERA-Interim driven ALADIN-Climate was compared against the MODIS land surface temperature for a 3-year period. Second, the impact of the ARPEGE global climate model driven ALADIN-Climate was assessed on the 2 m temperature of SURFEX and was validated against measurements of a suburban station for 30 years. The spatial extent of surface urban heat island (SUHI) is exaggerated in SURFEX from spring to autumn, because the urbanized gridcells are generally warmer than their rural vicinity, while the observed SUHI extent is more variable. The model reasonably simulates the seasonal means and diurnal cycle of the 2 m temperature in the suburban gridpoint, except summer when strong positive bias occurs. However, comparing the two experiments from the aspect of nocturnal UHI, only minor differences arose. The thorough validation underpins the applicability of SURFEX driven by ALADIN-Climate for future urban climate projections.
  • Lounassalo, Irinja; Hirvensalo, Mirja; Kankaanpaeae, Anna; Tolvanen, Asko; Palomäki, Sanna; Salin, Kasper; Fogelholm, Mikael; Yang, Xiaolin; Pahkala, Katja; Rovio, Suvi; Hutri-Kähönen, Nina; Raitakari, Olli; Tammelin, Tuija H. (2019)
    A physically active lifestyle and a diet rich in vegetables and fruits have a central role in promoting health. This study examined the associations between leisure-time physical activity (LTPA) trajectories and fruit and vegetable consumption (FVC) from childhood to middle age. The data were drawn from the Cardiovascular Risk in Young Finns Study with six age cohorts. Participants were 9 to 18 years (n = 3536; 51% females) at baseline in 1980 and 33 to 48 years at the last follow-up in 2011. LTPA and FVC were self-reported. LTPA trajectories were identified using latent profile analyses, after which the mean differences in FVC across the trajectories were studied. Active, low-active, decreasingly and increasingly active trajectories were identified for both genders. An additional trajectory describing inactivity was identified for females. Those who were persistently active or increased their LTPA had higher FVC at many ages when compared to their inactive or low-active counterparts (p <0.05). In females prior to age 42 and in males prior to age 24, FVC was higher at many ages in those with decreasing activity than in their inactive or low-active counterparts (p <0.05). The development of LTPA and FVC from childhood to middle age seem to occur in tandem.
  • Hardisty, Alex R.; Bacall, Finn; Beard, Niall; Balcazar-Vargas, Maria-Paula; Balech, Bachir; Barcza, Zoltan; Bourlat, Sarah J.; De Giovanni, Renato; de Jong, Yde; De Leo, Francesca; Dobor, Laura; Donvito, Giacinto; Fellows, Donal; Guerra, Antonio Fernandez; Ferreira, Nuno; Fetyukova, Yuliya; Fosso, Bruno; Giddy, Jonathan; Goble, Carole; Guentsch, Anton; Haines, Robert; Ernst, Vera Hernandez; Hettling, Hannes; Hidy, Dora; Horvath, Ferenc; Ittzes, Dora; Ittzes, Peter; Jones, Andrew; Kottmann, Renzo; Kulawik, Robert; Leidenberger, Sonja; Lyytikäinen-Saarenmaa, Paivi; Mathew, Cherian; Morrison, Norman; Nenadic, Aleksandra; de la Hidalga, Abraham Nieva; Obst, Matthias; Oostermeijer, Gerard; Paymal, Elisabeth; Pesole, Graziano; Pinto, Salvatore; Poigne, Axel; Fernandez, Francisco Quevedo; Santamaria, Monica; Saarenmaa, Hannu; Sipos, Gergely; Sylla, Karl-Heinz; Tähtinen, Marko; Vicario, Saverio; Vos, Rutger Aldo; Williams, Alan R.; Yilmaz, Pelin (2016)
    Background: Making forecasts about biodiversity and giving support to policy relies increasingly on large collections of data held electronically, and on substantial computational capability and capacity to analyse, model, simulate and predict using such data. However, the physically distributed nature of data resources and of expertise in advanced analytical tools creates many challenges for the modern scientist. Across the wider biological sciences, presenting such capabilities on the Internet (as "Web services") and using scientific workflow systems to compose them for particular tasks is a practical way to carry out robust "in silico" science. However, use of this approach in biodiversity science and ecology has thus far been quite limited. Results: BioVeL is a virtual laboratory for data analysis and modelling in biodiversity science and ecology, freely accessible via the Internet. BioVeL includes functions for accessing and analysing data through curated Web services; for performing complex in silico analysis through exposure of R programs, workflows, and batch processing functions; for on- line collaboration through sharing of workflows and workflow runs; for experiment documentation through reproducibility and repeatability; and for computational support via seamless connections to supporting computing infrastructures. We developed and improved more than 60 Web services with significant potential in many different kinds of data analysis and modelling tasks. We composed reusable workflows using these Web services, also incorporating R programs. Deploying these tools into an easy-to-use and accessible 'virtual laboratory', free via the Internet, we applied the workflows in several diverse case studies. We opened the virtual laboratory for public use and through a programme of external engagement we actively encouraged scientists and third party application and tool developers to try out the services and contribute to the activity. Conclusions: Our work shows we can deliver an operational, scalable and flexible Internet-based virtual laboratory to meet new demands for data processing and analysis in biodiversity science and ecology. In particular, we have successfully integrated existing and popular tools and practices from different scientific disciplines to be used in biodiversity and ecological research.
  • Tomppo, Erkki; Ronoud, Ghasem; Antropov, Oleg; Hytonen, Harri; Praks, Jaan (2021)
    The purpose of this study was to develop methods to localize forest windstorm damages, assess their severity and estimate the total damaged area using space-borne SAR data. The development of the methods is the first step towards an operational system for near-real-time windstorm damage monitoring, with a latency of only a few days after the storm event in the best case. Windstorm detection using SAR data is not trivial, particularly at C-band. It can be expected that a large-area and severe windstorm damage may affect backscatter similar to clear cutting operation, that is, decrease the backscatter intensity, while a small area damage may increase the backscatter of the neighboring area, due to various scattering mechanisms. The remaining debris and temporal variation in the weather conditions and possible freeze-thaw transitions also affect observed backscatter changes. Three candidate windstorm detection methods were suggested, based on the improved k-nn method, multinomial logistic regression and support vector machine classification. The approaches use multitemporal ESA Sentinel-1 C-band SAR data and were evaluated in Southern Finland using wind damage data from the summer 2017, together with 27 Sentinel-1 scenes acquired in 2017 and other geo-referenced data. The stands correctly predicted severity category corresponded to 79% of the number of the stands in the validation data, and already 75% when only one Sentinel-1 scene after the damage was used. Thus, the damaged forests can potentially be localized with proposed tools within less than one week after the storm damage. In this study, the achieved latency was only two days. Our preliminary results also indicate that the damages can be localized even without separate training data.
  • Hemilä, Harri (2017)
    Background: The relative scale has been used for decades in analysing binary data in epidemiology. In contrast, there has been a long tradition of carrying out meta-analyses of continuous outcomes on the absolute, original measurement, scale. The biological rationale for using the relative scale in the analysis of binary outcomes is that it adjusts for baseline variations; however, similar baseline variations can occur in continuous outcomes and relative effect scale may therefore be often useful also for continuous outcomes. The aim of this study was to determine whether the relative scale is more consistent with empirical data on treating the common cold than the absolute scale. Methods: Individual patient data was available for 2 randomized trials on zinc lozenges for the treatment of the common cold. Mossad (Ann Intern Med 125:81-8, 1996) found 4.0 days and 43% reduction, and Petrus (Curr Ther Res 59:595-607, 1998) found 1.77 days and 25% reduction, in the duration of colds. In both trials, variance in the placebo group was significantly greater than in the zinc lozenge group. The effect estimates were applied to the common cold distributions of the placebo groups, and the resulting distributions were compared with the actual zinc lozenge group distributions. Results: When the absolute effect estimates, 4.0 and 1.77 days, were applied to the placebo group common cold distributions, negative and zero (i.e., impossible) cold durations were predicted, and the high level variance remained. In contrast, when the relative effect estimates, 43 and 25%, were applied, impossible common cold durations were not predicted in the placebo groups, and the cold distributions became similar to those of the zinc lozenge groups. Conclusions: For some continuous outcomes, such as the duration of illness and the duration of hospital stay, the relative scale leads to a more informative statistical analysis and more effective communication of the study findings. The transformation of continuous data to the relative scale is simple with a spreadsheet program, after which the relative scale data can be analysed using standard meta-analysis software. The option for the analysis of relative effects of continuous outcomes directly from the original data should be implemented in standard meta-analysis programs.
  • Kankare, Ville; Joensuu, Marianna; Vauhkonen, Jari; Holopainen, Markus; Tanhuanpaa, Topi; Vastaranta, Mikko; Hyyppa, Juha; Hyyppa, Hannu; Alho, Petteri; Rikala, Juha; Sipi, Marketta (2014)
  • Ljungkvist, Marcus; Strandberg, Karin; Berntorp, Erik; Chaireti, Roza; Holme, Pål Andre; Larsen, Ole Halfdan; Lassila, Riitta; Jouppila, Annukka; Szanto, Timea; Zetterberg, Eva (2019)
    Introduction The thrombin generation assay-calibrated automated thrombogram (TGA-CAT) method is used to measure the overall coagulation capacity in plasma. However, the method is still considered to be a research tool, mainly because of its' lack of standardization. Aim Our study aimed to further raise the standardization level for the TGA-CAT method by evaluating a detailed standardization protocol and three reference plasmas' (RP)s ability to normalize results. Methods Six Nordic centres participated in the study, and with input from all centres a detailed laboratory standardization protocol based on the TGA-CAT manual of the manufacturer was established. Three types of plasma, hypo-,normal and hypercoagulable plasma were assessed. Three commercial lyophilized RPs were used for normalization of data. All samples were aliquoted at the Malmo centre and sent frozen at -20C to participating centres. Results Before normalization, all results under all testing conditions showed inter-laboratory coefficient of variability of 10% or lower except for endogenous thrombin potential (12%) and peak (14%) in hypo-plasma with 1 pmol/L tissue factor as starting agent. Successful normalization, improving variability in results, was obtained with two of the three evaluated RPs (HemosIL RP and Affinity RP). Conclusion With our standardization concept, we were able to produce TGA-CAT results as robust as standard coagulation assays used in the routine laboratories. Normalization with HemosIL RP may be considered in populations with low or unknown coagulability, while when analysing plasma samples from populations where hypercoagulability is known or suspected, normalization with Affinity RP may be preferred.
  • Pyykkönen, Henri; Rahkonen, Otto; Ratia, Nadja; Lähteenmäki, Sini; Tikkanen, Heikki; Piirilä, Päivi; Pitkänen-Argillander, Olli (2022)
    A modified Fontan procedure is performed to palliate single ventricle malformations. This hemodynamic arrangement sets systemic venous pressure unphysiologically high which predisposes the patient to severe long-term complications. As a means of self-care, exercise may ease transpulmonary flow. We investigated the effects of 6-month exercise prescription on pediatric Fontan patients. Eighteen stable Fontan patients (14 +/- 2.6 years, 160.4 +/- 11.3 cm, and 51.4 +/- 14.4 kg) were recruited. Baseline fitness was assessed by physical activity questionnaire, body composition, cardiorespiratory performance, and muscle fitness tests. Exercise prescription was individually tailored for a 6-month training period at home. At entrance to the study, Fontan patients had lower than normal maximal oxygen uptake (VO2max) of 28. +/- 5.9 ml/kg/min (61 +/- 11% of normal). VO2max significantly correlated with weekly amount of habitual exercise and muscle mass of the lower limbs (p < 0.001 for both). After 6 months of training, the patients had improved their anaerobic threshold of 18 +/- 3.5 vs 20 +/- 4.8 ml/kg/min, p = 0.007, and workload tolerance of 119 +/- 39 vs 132.4 +/- 44 W, p = 0.001. At EUROFIT tests, the patient muscle fitness was below age-matched reference, but correlations existed between VO2max and lower limb muscle tests. Our patients with Fontan hemodynamics were able to positively respond to an exercise program by enhancing submaximal performance which should be beneficial for getting through daily activities. Future studies should correlate whether hemodynamic findings at Fontan completion influence physical activity and exercise reserves, and whether these predict predisposition to chronic complications.
  • Lukes, Petr; Rautiainen, Miina; Manninen, Terhikki; Stenberg, Pauline; Mottus, Matti (2014)
    Land surface albedo is an essential climate variable controlling the planetary radiative energy budget, yet it is still among the main uncertainties of the radiation budget in the current climate modeling. To date, albedo satellite products have not been linked to extensive forest inventory data sets due to the lack of ground reference data. Here, we used comprehensive and detailed maps of forest inventory variables to couple forest structure and MODIS albedo products for both winter and summer conditions. We investigated how the relationships between forest variables and albedo change seasonally and along latitudinal gradients in the forest biomes of Finland between 60° and 70° N. We observed an increase in forest albedo with increasing latitude in winter but not in summer. Also, relationships between forest variables and the black-sky albedo or directional–hemispherical reflectance (DHR) at different latitudes were tighter in winter than in summer, especially for forest biomass. Summer albedo was only weakly correlated with the traditional inventory variables. Our findings suggest that the relationships between forest variables and DHR depend on latitude.
  • Pulkkinen, Jonna; Räikkönen, Eija; Jahnukainen, Markku; Pirttimaa, Raija (2020)
    Recent European and global trends in education have been to promote inclusive education and expand education, resulting in the increased provision of special education. In promoting inclusive education, recent special education reforms have also aimed to curtail the rise in identification rates for students in special education, for example, by focusing more on early support and discontinuing fiscal incentives to identify students with special educational needs. Using official special education statistics, we studied how Finland's special education system reforms changed the share of students in special education. In addition, we examined variations in special education provisions among municipalities before and after the reforms, and identified municipal-level predictors of variations. This study utilised piecewise linear latent growth curve modelling to analyse changes, thereby providing an example of how this method can be applied in policy reform studies. The results indicated, in particular, that the funding reform has incentivised municipalities to decrease identification rates for students in special education and to diminish special education provision. However, different municipalities have different special education provisions and have changed these provisions in varied ways. In particular, we found that small and large municipalities differ in special education practices and reform implementation.
  • Miettinen, Teemu; Nieminen, Anni I.; Mäntyselkä, Pekka; Kalso, Eija; Lotsch, Jorn (2022)
    Recent scientific evidence suggests that chronic pain phenotypes are reflected in metabolomic changes. However, problems associated with chronic pain, such as sleep disorders or obesity, may complicate the metabolome pattern. Such a complex phenotype was investigated to identify common metabolomics markers at the interface of persistent pain, sleep, and obesity in 71 men and 122 women undergoing tertiary pain care. They were examined for patterns in d = 97 metabolomic markers that segregated patients with a relatively benign pain phenotype (low and little bothersome pain) from those with more severe clinical symptoms (high pain intensity, more bothersome pain, and co-occurring problems such as sleep disturbance). Two independent lines of data analysis were pursued. First, a data-driven supervised machine learning-based approach was used to identify the most informative metabolic markers for complex phenotype assignment. This pointed primarily at adenosine monophosphate (AMP), asparagine, deoxycytidine, glucuronic acid, and propionylcarnitine, and secondarily at cysteine and nicotinamide adenine dinucleotide (NAD) as informative for assigning patients to clinical pain phenotypes. After this, a hypothesis-driven analysis of metabolic pathways was performed, including sleep and obesity. In both the first and second line of analysis, three metabolic markers (NAD, AMP, and cysteine) were found to be relevant, including metabolic pathway analysis in obesity, associated with changes in amino acid metabolism, and sleep problems, associated with downregulated methionine metabolism. Taken together, present findings provide evidence that metabolomic changes associated with co-occurring problems may play a role in the development of severe pain. Co-occurring problems may influence each other at the metabolomic level. Because the methionine and glutathione metabolic pathways are physiologically linked, sleep problems appear to be associated with the first metabolic pathway, whereas obesity may be associated with the second.
  • Lindberg, Nina; Miettunen, Jouko; Heiskala, Anni; Kaltiala-Heino, Riittakerttu (2017)
    Background: The mortality rate of young offenders is high. Furthermore, mortality in young offenders is associated with psychiatric and substance use disorders. The primary aim of this national register-based follow-up study was to investigate the mortality rate of Finnish delinquents who underwent a forensic psychiatric examination between 1980 and 2010. As delinquency is not a solid entity, we further aimed to compare the risk of premature death among different subgroups of the delinquents; violent versus non-violent offenders, offenders with alcohol use disorders versus those with no such diagnoses, offenders with schizophrenia spectrum disorders versus conduct-and personality-disordered offenders, under-aged versus young adult offenders, and, finally, boys versus girls. Methods: We collected the forensic psychiatric examination reports of all 15- to 19-year-old offenders who were born in Finland and had undergone the examination between 1.1.1980 and 31.12.2010 (n = 606) from the archives of the National Institute of Health and Welfare and retrospectively reviewed them. For each delinquent, four age-, gender- and place of birth-matched controls were randomly selected from the Central Population Register (n = 2424). The delinquents and their controls were followed until the end of 2015. The median follow-up time was 23.9 years (interquartile range 15.3-29.5). We obtained the mortality data from the causes of death register. Deaths attributable to a disease or an occupational disease were considered natural, and those attributable to an accident, suicide or homicide were considered unnatural. Results: By the end of the follow-up period, 22.1% (n = 134) of the delinquents and 3.4% (n = 82) of their controls had died (OR 8.11, 95% CI 6.05-10.86, p <0.001). Among boys, 22.0% (n = 121) of the delinquents and 3.7% (n = 81) of the controls had died (OR 7.38, 95% CI 5.46-9.95, p <0.001). Male delinquents' risk of unnatural death was almost 11-fold, of natural death more than twofold, and of unclear death more than fourfold compared to that of their controls. No girls had natural or unclear deaths, but 23.6% (n = 13) of the delinquents and 0.5% (n = 1) of the controls had died due to unnatural causes (OR 67.79, 95% CI 8.63-532.00, p <0.001). The violent delinquents' risk of premature death was twice that of the non-violent delinquents. The other comparisons demonstrated no statistically significant differences between subgroups. Conclusions: Even though the Finnish correction system prefers psychiatric treatment and rehabilitation over criminal sanctions, and the national health care system offers developmental-phase-specific psychiatric care, the mortality rate of delinquents, especially of those with a history of violent offences, is high. The excess mortality of offenders can be regarded as a specific public-health inequity that calls for more effective intervention procedures than those used thus far.
  • Holopainen, Markus; Vastaranta, Mikko; Hyyppa, Juha (2014)
  • Kallio-Kujala, I. J.; Turunen, H. A.; Raekallio, M. R.; Honkavaara, J. M.; Salla, K. M.; Casoni, D.; Hautajarvi, H. J.; Vainio, O. M. (2018)
  • Mohamedou, Cheikh; Kangas, Annika; Hamedianfar, Alireza; Vauhkonen, Jari (2022)
    Forest resource assessments based on multi-source and multi-temporal data have become more common. Therefore, enhancing the prediction capabilities of forestry dynamics by efficiently pooling and analyzing time-series and spatial sequential data is now more pivotal. Bayesian filtering and smoothing provide a well-defined formalism for the fusion or assimilation of various data. We ascertained how often the generic, standardized Bayesian framework is used in the scientific literature and whether such an approach is beneficial for forestry applications. A review of the literature showed that the use of Bayesian methods appears to be less common in forestry than in other disciplines, particularly remote sensing. Specifically, time-series analyses were found to favor ad hoc methods. Our review did not reveal strong numeric evidence for better performance by the various Bayesian approaches, but this result may be partly due to the challenge in comparing a variety of methods for different prediction tasks. We identified methodological challenges related to assimilating predictions of forest development; in particular, combining modelled growth with disturbances due to both forest operations and natural phenomena. Nevertheless, the Bayesian frameworks provide possibilities to efficiently combine and update prior and posterior predictive distributions and derive related uncertainty measures that appear under-utilized in forestry.
  • Bockerman, Petri; Haapanen, Mika; Hakulinen, Christian; Vainiomaki, Jari (2021)
    Background: The secular decline in labor market participation and the concurrent increase in opioid use in many developed countries have sparked a policy debate on the possible connection between these two trends. We examined whether the use of prescription opioids was connected to labor market outcomes relating to partici-pation, employment and unemployment among the Finnish population. Methods: The working-age population (aged 19-64 years) living in Finland during the period 1995-2016 was used in the analyses (consisting of 67 903 701 person-year observations). Lagged values of prescription opioid use per capita were used as the exposure. Instrumental variables (IV) estimation method was used to identify causal effects, where opioid use per capita for the elderly (65-95-year-old) was used as an instrument for the opioid use per capita for the working-age population of the same gender, education and region. Results: Increased opioid use led to worse labor market outcomes in the long run, with the effect size of 16 % and 20 %, compared to the standard deviation of the employment and participation rates. On the contrary, in the short run, increased opioid use had positive employment effects. Conclusions: Policymakers should take the contradictory short-and long-term effects into account while considering regulation and monitoring of opioid use. Regulating and monitoring long-term prescription opioids is crucial for reducing their negative labor market consequences.
  • Khan, Daulat Haleem; Bashir, Sajid; Figueiredo, Patricia; Santos, Helder A.; Khan, Muhammad Imran; Peltonen, Leena (2019)
    The aim of the present study was to develop an optimized niosome formulation for the encapsulation of a poorly water-soluble drug by the ecological probe sonication method. Pluronic L121 and Span 60 were used as surface active agents and the optimization of the composition was made with the aid of Design of Experiment (DoE) concept. Rifampicin was used as a model drug. Concentration levels of charge inducing agent, dicetylphosphate (DCP), and Pluronic L121 were studied as variables. Prepared niosomes with varying concentrations of DCP and Pluronic L121 resulted in small sized niosomes with sizes ranging from 190 nm to 893 nm. During the four weeks stability testing, the particle sizes were reduced slightly. The formulation containing 2 mg of DCP resulted in most stable niosomes with 75.37% entrapment efficiency. All the niosomal formulations showed higher in vitro drug release rates as compared to bulk drug formulation. As a conclusion, rifampicin loaded niosomes prepared with Pluronic L121 and Span 60 resulted in stable, small sized niosomes with improved drug release profile.