Browsing by Subject "EXPLANATION"

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  • Järvinen, Teppo L. N.; Sihvonen, Raine; Bhandari, Mohit; Sprague, Sheila; Malmivaara, Antti; Paavola, Mika; Schuenemann, Holger J.; Guyatt, Gordon H. (2014)
  • Hoffmann, Rasmus; Kröger, Hannes; Tarkiainen, Lasse Hannes; Martikainen, Pekka Tapani (2019)
    Differences in mortality between groups with different socioeconomic positions (SEP) are well-established, but the relative contribution of different SEP measures is unclear. This study compares the correlation between three SEP dimensions and mortality, and investigates differences between gender and age groups (35-59 vs. 60-84). We use an 11% random sample with an 80% oversample of deaths from the Finnish population with information on education, occupational class, individual income, and mortality (n=496,658; 274,316 deaths between 1995 and 2007). We estimate bivariate and multivariate Cox proportional hazard models and population attributable fractions. The total effects of education are substantially mediated by occupation and income, and the effects of occupation is mediated by income. All dimensions have their own net effect on mortality, but income shows the steepest mortality gradient (HR 1.78, lowest vs. highest quintile). Income is more important for men and occupational class more important among elderly women. Mortality inequalities are generally smaller in older ages, but the relative importance of income increases. In health inequality studies, the use of only one SEP indicator functions well as a broad marker of SEP. However, only analyses of multiple dimensions allow insights into social mechanisms and how they differ between population subgroups.
  • Kiiski, Iiro; Ollikainen, Elisa; Artes, Sanna; Järvinen, Päivi; Jokinen, Ville; Sikanen, Tiina (2021)
    UDP-glucuronosyltransferases (UGTs), located in the endoplasmic reticulum of liver cells, are an important family of enzymes, responsible for the biotransformation of several endogenous and exogenous chemicals, including therapeutic drugs. However, the phenomenon of 'latency', i.e., full UGT activity revealed by disruption of the microsomal membrane, poses substantial challenges for predicting drug clearance based on in vitro glucuronidation assays. This work introduces a microfluidic reactor design comprising immobilized human liver microsomes to facilitate the study of UGT-mediated drug clearance under flow-through conditions. The performance of the microreactor is characterized using glucuronidation of 8-hydroxyquinoline (via multiple UGTs) and zidovudine (via UGT2B7) as the model reactions. With the help of alamethicin and albumin effects, we show that conducting UGT metabolism assays under flow conditions facilitates in-depth mechanistic studies, which may also shed light on UGT latency.
  • Kuokkanen, Jesse; Rusanen, Anna-Mari (2018)
  • Jokinen, Maarit; Hanski, Ilpo; Numminen, Elina; Valkama, Jari; Selonen, Vesa (2019)
    Species distribution models (SDMs) can be used to predict species occurrence and to seek insight into the factors behind observed spatial patterns in occurrence, and thus can be a valuable tool in species conservation. In this study, we used MaxEnt software to explain the occurrence of a protected forest-dwelling species, the Siberian flying squirrel. We produce occurrence maps covering the main distribution area for the species in the European Union. Using an exceptionally extensive presence-absence dataset collected with a standardized method, we evaluated the relative role of predation pressure, climate, and amount of habitat affecting flying squirrel occurrence. We found that regional variation in mean winter temperature had relatively large predictive power for flying squirrel occurrence. In addition, the regional abundance of flying squirrels was partly explained by differences in predation pressure. The results also support the conclusion that areas with older forests and nearby agricultural areas are optimal for the species. Our study shows that multiple factors affect the species' occurrence in large spatial scales. We also conclude that climate is having a large effect on species occurrence, and thus the changing climate has to be taken into account in conservation planning. Our results help conservation managers in targeting surveys and protection measures on various spatial scales, and decision makers in focusing on the factors that drive the species' occurrence. Our results also indicate that we would need additional tools and measures in the EU for achieving a favourable conservation status of those species that occur in commercial forests.
  • Marshall, Leon; Biesmeijer, Jacobus C.; Rasmont, Pierre; Vereecken, Nicolas J.; Dvorak, Libor; Fitzpatrick, Una; Francis, Frederic; Neumayer, Johann; Odegaard, Frode; Paukkunen, Juho P. T.; Pawlikowski, Tadeusz; Reemer, Menno; Roberts, Stuart P. M.; Straka, Jakub; Vray, Sarah; Dendoncker, Nicolas (2018)
    Bumblebees in Europe have been in steady decline since the 1900s. This decline is expected to continue with climate change as the main driver. However, at the local scale, land use and land cover (LULC) change strongly affects the occurrence of bumblebees. At present, LULC change is rarely included in models of future distributions of species. This study's objective is to compare the roles of dynamic LULC change and climate change on the projected distribution patterns of 48 European bumblebee species for three change scenarios until 2100 at the scales of Europe, and Belgium, Netherlands and Luxembourg (BENELUX). We compared three types of models: (1) only climate covariates, (2) climate and static LULC covariates and (3) climate and dynamic LULC covariates. The climate and LULC change scenarios used in the models include, extreme growth applied strategy (GRAS), business as might be usual and sustainable European development goals. We analysed model performance, range gain/loss and the shift in range limits for all bumblebees. Overall, model performance improved with the introduction of LULC covariates. Dynamic models projected less range loss and gain than climate-only projections, and greater range loss and gain than static models. Overall, there is considerable variation in species responses and effects were most pronounced at the BENELUX scale. The majority of species were predicted to lose considerable range, particularly under the extreme growth scenario (GRAS; overall mean: 64% +/- 34). Model simulations project a number of local extinctions and considerable range loss at the BENELUX scale (overall mean: 56% +/- 39). Therefore, we recommend species-specific modelling to understand how LULC and climate interact in future modelling. The efficacy of dynamic LULC change should improve with higher thematic and spatial resolution. Nevertheless, current broad scale representations of change in major land use classes impact modelled future distribution patterns.
  • Kuorikoski, Jaakko; Marchionni, Caterina (2014)
    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant. (C) 2014 Elsevier Ltd. All rights reserved.