University of Helsinki
  • Helsinki, Finland
Recent publications
Background Hypothesis-free studies applying advanced statistical analysis of objective working hour patterns and occupational accidents are lacking. This study aimed to identify patterns of working hours among hospital employees and to investigate the associations between the identified patterns and the risk of an occupational accident. Method In this cohort study of 4419 hospital employees, we collected electronic payroll-based working hour data (i.e., timing and duration) for each participant and linked them to records of occupational accident register between 2008 and 2018. We used optimal matching to assess similarity between individual working hour patterns for a period of 7 days preceding an accident or, for employees without an accident, a random pseudo-accident date. Using cluster analysis, we categorized employees into working hour pattern clusters. Log-binomial regression was used to examine risk ratios (RR) with 95 % confidence intervals (CI) of an occupational accident between cluster memberships. Results 1626 participants experienced an occupational accident which took place either at the workplace (65 %) or while commuting (35 %). Six clusters of working hour patterns were identified. Compared to the cluster with the fewest accidents, clusters with a higher proportion of accidents were characterized by late work shifts and a high proportion of quick returns (<11-hour shift interval,) and long work shifts (>12-hour shift), RR 1.31, 95 %CI 1.13–1.52 for the cluster with the most accidents. Conclusions This data-driven study suggests that working late and long with insufficient rest is associated with increased probability of occupational accidents. Working hour arrangements in 24/7 care of hospital merit attention to regularity and sufficient rest to support occupational safety.
Refractive index engineering is a key element in the design of optoelectronic device structures. In this work we present a method for the fabrication of buried hollow channels, periodically arranged inside GaN structures. The method is based on selective area doping and electrochemical etching. Channels width is defined by the selective area ion implantation mask geometry while the channel vertical dimension depends on the implantation energy and annealing conditions. In this work we used implantation with Si 100 keV and dose 2.6·10¹⁵ cm⁻² into GaN. Next, a 100 nm GaN layer was grown by plasma-assisted molecular beam epitaxy (PAMBE). After annealing at 1070 °C for 5 min, selectively doped regions were removed in the process of electrochemical etching (ECE), forming periodically arranged empty volumes. Annealing resulted in partial strain removal as observed by X-Ray diffraction. Surface roughness was evaluated at every stage of the process: after implantation, after regrowth and after annealing, and it is promising for the integration of the proposed technology with device fabrication and processing. The flexibility in the mask design for selective ion implantation and a high refractive index contrast between GaN and air, make the proposed technology attractive for the fabrication of buried photonic structures such as diffraction gratings.
Sixteen multiparous Holstein cows in four blocks of 4 × 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller’s grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27% as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows’ I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.
Basidiomycota brown rot fungus (Fomitopsis pinicola) and two white rot fungi (Phlebia radiata, Trichaptum abietinum) were cultivated on thin slices of spruce wood individually and in interspecies combinations. Within 12 months, F. pinicola substantially decomposed spruce wood observed as mass loss, also in three-species combinations. However, white rot fungi through hyphal interactions negatively affected the brown-rot indicative iron reduction capacity of F. pinicola. Decay-signature gene expression in mycelial interaction zones indicated suppression of brown rot mechanism but stimulation of enzymatic white-rot lignin attack by P. radiata. Wood ultrastructure imaging showed white-rot dominance in the fungal combinations, whereas destructive brown-rot was evident with F. pinicola alone. Our results confirm the dynamic pattern of enzyme production in fungal combinations, and transition from brown to white rot decomposition metabolism during the late stage of wood decay after one year of interspecific interactions.
This paper develops, tests and validates a Multi-sensory Public Participation GIS (MSPPGIS) method combining the qualities of soundscapes and landscape values mapping. The development of the method involved: a) Public Participation GIS survey design; b) three-phase evaluation of survey addressing analytical, applicability and usability criteria; c) survey refinement; d) sampling and data collection, and; e) spatial data analysis. The analysis consisted of hotspot mapping involving Kernel Density Estimation, spatial overlap assessment using Jaccard coefficients and value compatibility analysis showing the level of spatial compatibility between positive landscape values and positive and negative soundscapes. Results indicated very low to low spatial overlap between the different landscape values and pleasant/unpleasant sound hotspots, suggesting that landscape values do not necessarily reflect sonic perception of urban green and blue spaces. Pleasant and unpleasant sounds were located closer to home than landscape values (except for urban life values), indicating that respondents’ soundscape ‘cognitive map’ is smaller in spatial range. The MSPPGIS method enables the elicitation of a more dynamic and diverse set of sounds compared to previous soundscape mapping which tend to focus on 'noise' instead of multiple experiences of different sounds. Also, the combination of landscape values and soundscapes in MSPPGIS provides for a more integrated assessment of ‘where’ and ‘how’ to design urban green infrastructure.
The mapping of ecosystem service (ES) provisioning often lacks decision-makers’ preferences on the ESs provided. Analyzing the related uncertainties can be computationally demanding for a landscape tessellated to a large number of spatial units such as pixels. We propose stochastic multicriteria acceptability analyses to incorporate (unknown or only partially known) decision-makers’ preferences into the spatial forest management prioritization in a Scandinavian boreal forest landscape. The potential of the landscape for the management alternatives was quantified by airborne laser scanning based proxies. A nearest-neighbor imputation method was applied to provide each pixel with stochastic acceptabilities on the alternatives based on decision-makers’ preferences sampled from a probability distribution. We showed that this workflow could be used to derive two types of maps for forest use prioritization: one showing the alternative that a decision-maker with given preferences should choose and another showing areas where the suitability of the forest structure suggested different alternative than the preferences. We discuss the potential of the latter approach for mapping management hotspots. The stochastic approach allows estimating the strength of the decision with respect to the uncertainty in both the proxy values and preferences. The nearest neighbor imputation of stochastic acceptabilities is a computationally feasible way to improve decisions based on ES proxy maps by accounting for uncertainties, although the need for such detailed information at the pixel level should be separately assessed.
Background It remains unclear how pre-existing depression, anxiety, and diabetes of different durations are associated with the risk of pancreatic cancer, its clinical characteristics, treatment modalities, and subsequent survival. Methods From a register-based random sample of Finns residing in Finland at the end of the period 1987–2007, 6492 patients diagnosed with primary pancreatic cancer in 2000–2014, and 32 460 controls matched for birth cohort and sex, were identified. Pre-existing depression, anxiety, and diabetes were ascertained from the records of prescribed medication purchases. Information on pancreatic cancer outcomes was obtained from the Finnish cancer register. Data were analyzed using logistic and Cox regressions. Results The risk of developing pancreatic cancer was found to be associated with long-term anxiety (treatment started 36 + months before the cancer diagnosis) (odds ratio (OR): 1.13, 95% confidence interval (95%CI): 1.04–1.22) and long-term diabetes (OR 1.72, 95%CI 1.55–1.90), as well as with new-onset (treatment started 0–24 months before the cancer diagnosis) depression (OR 1.59, 95%CI 1.34–1.88), anxiety (OR 1.76, 95%CI 1.50–2.07), and diabetes (OR 3.92, 95%CI 3.44–4.48). However, the effects of these new-onset conditions were driven by cases that began treatment within 3 months before the cancer diagnosis (concomitant period). Patients with long-term depression, anxiety and diabetes and those with new-onset anxiety had a higher risk of not receiving standard treatments. Lower survival was found for pancreatic cancer patients with new-onset depression (hazards ratio (HR) 1.38, 95%CI 1.16–1.64). Survival was not associated with pre-existing anxiety or diabetes. Conclusions The associations between pancreatic cancer risk and pre-existing depression and anxiety were mostly driven by concomitant effects. Individuals with diabetes, regardless of duration, should be closely monitored for pancreatic cancer. Pancreatic cancer patients with new-onset depression should be targeted to improve their survival.
Modification, fragmentation and loss of boreal forest habitats have been intensive during the last century due to forestry practises and land use. This has been related to population declines of many forest species, yet the mechanisms affecting on the background are largely unknown. The willow tit, a primary cavity-nesting species that was once the 4th most common bird species in Finland is nowadays endangered. Earlier findings suggest that the willow tit population is affected by the reduction of nesting sites, decaying snags in forests and the loss of mature forests which contain the food storages during the winter. In this study we are searching for the mechanisms how the forest management methods could explain the decline of the willow tit population. We used long-term breeding data of the willow tit nesting sites from 1990 to 2020 collected in a study area in northern Finland to analyse if forest management affected nearest neighbour distances and natal dispersal and breeding dispersal distances. We used Geographic Information System (GIS) methods to combine the ecological breeding data to accurate spatial forest management and habitat quality data. The data was analysed with linear mixed models. We found that clear-cuttings affected the willow tit dispersal and neighbouring nest distances more than thinnings. Both clear-cuttings and thinnings increased the nearest neighbour distances. The natal and breeding dispersal distances were lengthened by increasing proportions of clear-cuttings. The habitat loss caused by clear-cuttings and the decrease in habitat quality caused by thinnings has had a major role in the decline of the willow tit population. The forest management actions were estimated to explain about 65 % of the willow tit breeding density decrease in the study area. The effects of forest management were witnessed in a cumulative 0–30-year period meaning that forest management causes long-term habitat degradation and loss. Availability of deciduous snags in the forests can compensate the habitat loss to some extent by providing better breeding opportunities. As the effects of clear-cutting were more severe to the willow tit than thinning, we recommend using other forest management methods than clear-cutting as the main management method.
Artificial light at night, often referred to as 'light pollution', is a global environmental problem that threatens many nocturnal organisms. One such species is the European common glow-worm (Lampyris noctiluca), which relies on the ability of sedentary bioluminescent females to attract flying males to mate. Previous studies show that broad-spectrum white artificial light interferes with mate attraction in this beetle. However, much less is known about wavelength-specific effects. In this study, we experimentally investigate how the peak wavelength (color) of artificial light affects glow-worm mate attraction success in the field by using dummy females that trap males landing to mate. Each dummy was illuminated from above by either a blue (peak wavelength: 452 nm), white (449 nm), yellow (575 nm), or red (625 nm) LED lighting, or light switched off in the control. We estimated mate attraction success as both the probability of attracting at least one male and the number of males attracted. In both cases, mate attraction success depended on the peak wavelength of the artificial light, with short wavelengths (blue and white) decreasing it more than long wavelengths (yellow and red). Hence, adjusting the spectrum of artificial light can be an effective measure for mitigating the negative effects of light pollution on glow-worm reproduction.
Nephrotic syndrome (NS) defines a clinical entity of proteinuria, hypoproteinemia, and edema. Proteinuria is caused by an acquired or genetic defect in the glomerular filtration barrier of the kidney. So far, over 50 genes responsible for NS have been identified. Mutations in genes encoding for podocyte proteins nephrin (NPHS1), podocin (NPHS2), Wilms tumor suppressor 1 (WT1), phospholipase C ε1 (PLCE1), and laminin β2 (LAMB2) account for the majority of the observed disorders. Gene mutations are more probable in pediatric (especially in infants) than adult patients. Autosomal recessive inheritance is typical for NS in small children while dominant forms are more likely observed in adults. Gene analysis using next-generation sequencing is recommended in NS cases not responding to immunosuppressive medication. Renal failure often develops in a few years after diagnosis even with an optimal supportive therapy. Kidney transplantation is a successful curative treatment option for these patients.
The beverage industry generates a huge quantity of by-products and waste largely in the form of spent grains and pomace. These are generally used as low-value animal feed, composts, fertilizers or a source of bio-fuel. However, these by-products and waste are attractive sources of bioactive compounds such as (poly) phenols, dietary fiber and essential oils. Through enzymatic bioprocessing, it is possible to efficiently recover these high-value ingredients for food applications. This chapter discusses the different types of by-products and how these waste and/or by-products, through biotechnological innovations, are being utilized by the food and beverage industry as the main ingredient or as a fortifying agent along with developments for an upcycled food certification mark. The reintegration of beverage industrial by-products into the food chain would develop a more environment friendly and sustainable food system.
We study the impact of fake news on votes for populist parties in the Italian elections of 2018. Our empirical strategy exploits the historical variation in Italian-speaking and German-speaking voters in the Italian region of Trentino Alto-Adige/Südtirol as an exogenous source of assignment to fake news exposure. Using municipal data, we compare the effect of exposure to fake news on the vote for populist parties in the 2013 and 2018 elections. To do so, we introduce a novel indicator of populism using text mining on the Facebook posts of Italian parties before the elections. Our findings support the view that exposure to fake news favours populist parties regardless of prior support for populist parties, but also that fake news alone cannot explain most of the growth in populism.
Witches’ brooms are a deformity or structural alteration commonly observed as a disease symptom in trees or woody plants. Nematodes, insects, mites, oomycetes, fungi, viruses, and phytoplasma typically cause these deformities. In this chapter, we will primarily focus on witches’ broom disease of birch tree. Birch witches’ broom disease is caused by Taphrina betulina and other closely related Taphrina species. This understudied forest tree disease is considered by many not to be a serious threat to birch. However, the few studies that have addressed this have found that it can cause significant losses to birch forestry production. In this review, we discuss several aspects of this disease and its causative fungi, including, the host infection biology and pathogen lifecycle, the impact of this disease on birch, the symptoms of this disease, and morphology of its characteristic tumors, the defining characteristics of T. betulina, the Taphrina that infects Betula species, and their distribution, ecology, and host specificity. As not all aspects of Taphrina biology have been specifically addressed in T. betulina, the genus Taphrina, in general, is covered to give insight into common features of members of this genus, including insights from recent genome sequencing studies.
The purpose of this theoretical investigation was to examine critical thinking as a realization of human cooperation, affecting both mental health and social welfare. Although critical thinking contains a critical stance toward any asserted standpoint, such a critical stance appears, paradoxically, to have developed from cooperation and the shared goals of human beings. Moreover, although critical thinking has been seen in academic literature to be anchored on culturally developed rules and principles of rational dialogue as well as on effective learning methods, investigators have not interconnected critical thinking and human cooperation comprehensively enough. To solve the dilemma, we will use available scientific knowledge to examine how cooperation and socially shared goals are realized in critical thinking, especially in a critical stance. The view of critical thinking as cooperation places it ontogenetically and phylogenetically into a wider theoretical framework which also provides a novel perspective on mental health and social welfare. The deterioration of rational thinking in the context of mental disorders may be explained by failures of cooperation, which can contain epistemic distrust and an inability to mentalize the viewpoints of others. These features may clarify some causes why some contemporary dialogues and critical contributions are divisive in worldwide, especially in social media.
As the world embraced Artificial Light at Night (ALAN) and its numerous benefits, the transforming nocturnal environment witnessed the negative impacts of this contaminant of emerging concern, and its consequent Light Pollution, on the fitness and populations of numerous organisms. Over the decades, India's unbridled population growth and rapid urbanization have accelerated the use of ALAN yet research on light pollution, in India, as a potential biodiversity threat remains almost untapped. The present study utilized nighttime light data from the Visible and Infrared Imaging Radiation Suite Day-Night Band (VIIRS DNB) to investigate the spatio-temporal trends of ALAN across India's major river basins, emphasizing on critical riparian habitats. The study also aimed to identify the significant effects on night-time brightness in these habitats. Our findings indicated the year, riparian fauna group and presence within and near protected areas as significant determinants of light pollution in the riparian habitats of species of conservation concern. Light pollution was observed to grow in these habitats from the year 2012 to 2020. Higher radiance, in general, were observed for habitats near conurbations, airports, ports and docks, petroleum refineries, thermal power plants, and nuclear power stations. Otter and Turtle habitats had higher night-time brightness than other groups. The significant increase of ALAN within a span of eight years is concerning, particularly for the critically endangered gharial, which was observed to inhabit predominantly darker habitats. This, along with the gaps in our knowledge regarding the effects of ALAN on these species, urgently warrants a better understanding of its effects in riparian ecosystems. We have highlighted research gaps on ALAN from India's perspective and suggest that national biodiversity programs should evaluate ALAN as a potential biodiversity threat to limit its expansion in critical riparian ecosystems.
The alternative enzymes of the respiratory chain, which are found in all the kingdoms of life, except for vertebrates, have received great interest for the treatment of disorders related to mitochondrial dysfunction. These enzymes have recently been used in cellular and animal models to understand and mitigate pathologies from mitochondrial diseases to Parkinson’s disease and cancer. The functional properties of these alternative enzymes have also helped to answer fundamental questions about the role of the respiratory chain in maintaining cellular and tissue metabolism. At the same time, the compatibility of these enzymes with mammalian metabolism has been widely characterized, and rejected on specific occasions. Although many questions remain to be answered regarding the metabolic impact of the alternative enzymes of the respiratory chain in humans, their potential as a therapeutic and research tool is starting to unravel.
Much attention has been paid on dioecious plants and their responses to environmental stresses. However, little information is available on sexual dimorphism in Populus euphratica Oliver, which usually grows in arid desert areas and exposes to drought and salinity stress. In this study, we investigated female and male seedlings of P. euphratica and their growth and anatomical structure, gas exchange, water and nitrogen use, oxidative stress and antioxidants under drought, salinity, and the combined stress. We found that there were no significant sexual differences in P. euphratica under control conditions (well-watered and no salt addition). However, males showed stronger resistance to drought, salinity and especially to the combined stress, as they had protective structures, higher biomass, net photosynthetic rate (Pn), water and nitrogen use, osmotic adjustment and reactive oxygen species (ROS) scavenging ability, and a lower leaf Cl– content under stress conditions. The significant sex × drought × salinity interactions for biomass, Pn, water and nitrogen use, superoxide radicals (O2–), proline and free amino acids (FAA) indicated that sexual dimorphism occurs depending on the stress gradients, implying contrasting adaptive responses and life strategies in P. euphratica females and males under stress conditions. Due to the sexual dimorphism of P. euphratica under drought and salinity stress, more severe shifts in the sex ratio of P. euphratica forests may occur under future climate change with aggravated aridity and soil salinity.
The development of porosity during rock weathering is a key process controlling nutrients release, water holding capacity available for plants and water flow. Here we used X-ray Computed Tomography (XRCT) and ¹⁴C PolyMethylMethAcrylate (PMMA) autoradiography to show how cracks are created and enlarged during initial weathering stages (saprock and saprolite) of granodiorite in southern Brazil (Viamão - RS). The physical evolution is characterized by imaging the pore network, using ¹⁴C-PMMA and XRCT methods. Combined with bulk porosity measurements, they highlight the increase in porosity with the degree of weathering (un-weathered rock Φ = 1.66 %, saprolite Φ = 11.7 %). This increase is related to the joint increase of the density of the cracks (un-weathered rock D = 0.28 mm⁻¹, saprolite D = 0.94 mm⁻¹) and of the average opening of the microcracks (un-weathered rock w = 2.4 µm, saprolite w = 3.9 µm) and macrocracks (un-weathered rock w = 176 µm, saprolite w = 400 µm). However, these average crack openings do not account for the variability of the openings that govern the flows, characterized here by specific distribution ranging from the submicrometre to the centimetre scale. The results highlight that the pore network of the un-weathered rock plays a key role in the initial stages or incipient weathering. The density and aperture and cracks increase following the subcritical cracking concept and new pores are formed by chemo-mechanical processes. The presence/absence of initial fractures in the regolith is certainly a key parameter controlling the weathering of different rock types (mafic vs felsic).
Tungsten is the material of choice for plasma-facing components planned for fusion reactors. The high irradiation doses accumulated over years of operation from its exposure to high-energy fusion neutrons are expected to alter its microstructure and so degrade its structural properties. In order to understand the defect accumulation on atomistic resolution, computer simulations are a necessity. To reach reactor-relevant doses, overlapping collision cascade simulations can be carried out with Molecular Dynamics, but these simulations are limited by the computationally expensive accumulation of the damage. In this article, we investigate several accelerated methods and compare them to the computationally heavy cumulative accumulation simulations. We find that the acceleration technique chosen can dramatically affect the defect evolution as a function of dose. However, applying ‘cascade annealing’, by adding more collision cascades to configurations generated by the accelerated simulations leads to similar end results for all measured properties, regardless of the technique used to produce the initial damage. This indicates that accelerated simulation techniques can be used to efficiently generate an initial defect population, provided sufficient cascade annealing is subsequently applied.
Rubber and oil palm are two main crops threatening biodiversity and natural habitats in Southeast Asia. The expansion of these crops has been transforming landscapes in the region replacing vast areas of forests and other croplands. Here, we utilize existing crop expansion time series data and tree plantation maps combined with image interpretation methods to identify rubber-associated land cover dynamics including the extent of rubber conversion to oil palm. While existing rubber plantations in 2014 had been converted from multiple land cover types including forests, we documented more rubber conversion to oil palm and other land cover types between 2014 and 2020. The percentage conversion of existing rubber plantations to oil palm was 1.9% and 2.6% for Indonesia and Malaysia, respectively. The estimated overall rate of this conversion was 10 500 ha/year. This slow readjustment of rubber and oil palm, following their competitive advantages, may reshape agricultural threats to tropical and sub-tropical environments through indirect land-use change. Continuation of this trend could lead to displacement of rubber to countries like Cambodia, Laos, and Myanmar threatening remaining natural habitats. Sustainability measures should therefore simultaneously focus on both oil palm and rubber considering their coupled transboundary displacement trends.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
13,860 members
Miikka Tarkia
  • Department of Pharmacology
P.O. Box 33 (Yliopistonkatu 4), 00014, Helsinki, Finland
Head of institution
Kansleri Thomas Wilhelmsson
+358 9 1911 (switchboard)