Artikkelit: Recent submissions

Now showing items 1-20 of 37920
  • Kalland, Mirjam; Salo, Saara (2020)
    Parent-child interaction has long-term impact on child development. Support for parenthood can be universal, targeted or intense. This article focuses on intervention models with at least some empirical evidence and most of which are currently available in Finland. Based on intervention research, there is evidence on the positive impact of intervention on parenting and parent-child interaction. To ensure the availability of intervention models, it is important for professionals to have access to training and to information of evidence-based interventions. A resource for professionals is the web-site "Kasvun tuki" that is designed to disseminate information and promote awareness of interventions and their effectiveness
  • Back, Philipp; Suominen, Antti; Malo, Pekka; Tahvonen, Olli; Blank, Julian; Deb, Kalyanmoy (ACM, 2020)
    Sustainable forest management is a crucial element in combating climate change, plastic pollution, and other unsolved challenges of the 21st century. Forests not only produce wood - a renewable resource that is increasingly replacing fossil-based materials - but also preserve biodiversity and store massive amounts of carbon. Thus, a truly optimal forest policy has to balance profit-oriented logging with ecological and societal interests, and should thus be solved as a multi-objective optimization problem. Economic forest research, however, has largely focused on profit maximization. Recent publications still scalarize the problem a priori by assigning weights to objectives. In this paper, we formulate a multi-objective forest management problem where profit, carbon storage, and biodiversity are maximized. We obtain Pareto-efficient forest management strategies by utilizing three state-of-the-art Multi-Objective Evolutionary Algorithms (MOEAs), and by incorporating domain-specific knowledge through customized evolutionary operators. An analysis of Pareto-efficient strategies and their harvesting schedules in the design space clearly shows the benefits of the proposed approach. Unlike many EMO application studies, we demonstrate how a systematic post-optimality trade-off analysis can be applied to choose a single preferred solution. Our pioneering work on sustainable forest management explores an entirely new application area for MOEAs with great societal impact.
  • Global Burden of Disease Cancer Collaboration; Fitzmaurice, C.; Doku, D.T.; Hadkhale, K.; Meretoja, T.J.; Neupane, S. (2019)
    Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.
  • Pernaa, Johannes; Aksela, Maija (ALMA MATER STUDIORUM – University of Bologna, 2021)
    The lack of relevance is a major challenge in chemistry education. In the last two decades, a lot of research and development projects for increasing the relevancy have been conducted in all educational levels, expect in chemistry teacher education. This research is filling this knowledge gap by investigating what kind of learning methods in pre-service chemistry teacher education have high and low vocational relevance. The relevance of different learning methods included in chemistry teacher education courses are analysed by studying future chemistry teachers’ perceptions. Research was carried out as a case study utilising a mixed methods approach. Data was collected via an online questionnaire. The total number of respondents was 72. According to this research, laboratory activities, teaching exercises (e.g. teaching for peers or pupils in a non-formal learning environment study visit) and discussions (e.g. group discussions) were experienced the most vocationally relevant. Writing exercises were experienced the least relevant. All highly relevant learning methods stimulated high-order thinking skills and supported collaborative learning. The level of experienced relevance was mostly intrinsic (skills and knowledge for career) and it had both present and future focus. These results can be used for developing vocationally high relevance learning methods for pre-service chemistry teacher education.
  • Välimäki, Susanna (2021)
    SKS:n Kansallisbiografiaan toimitettiin vuoden 2020 aikana runsaasti uusia elämäkerta-artikkeleita säveltäjä- ja muusikkonaisista. Toimituskuntaan kuulunut Susanna Välimäki kertoo artikkelissaan tästä Suomen musiikin naishistoriaa esiin tuovasta toimitus- ja tutkimustyöstä, jonka tulokset julkaistiin huhtikuussa 2021 uusina Kansallisbiorgafian elämäkerta-artikkeleina.
  • Su, Lantian; Liu, Xinxin; Jin, Guangyao; Ma, Yue; Tan, Haoxin; Khalid, Muhammed; Romantschuk, Martin; Yin, Shan; Hui, Nan (2021)
    Simple Summary Environmental changes of habitat shaped the sable (Carnivora Mustelidae Martes zibellina) gut microbial community structure and altered the functions of gut microbiota, showing that the wild sable gut microbial community diversity was resilient and responded to environment change. Elevated habitat is a pivotal factor for wild sable survival and reproduction, and the adaptability is in part enabled through their gut microbial communities. Our observations show that despite having been forced to migrate from low altitudes to high altitudes because of anthropogenic habitat encroachment, wild sables showed robustness in adapting to harsh conditions. Additionally, we propose that the crucial factor enabling wild sables to survive in changeable environments was their gut microbial communities. It is widely understood that harsh conditions, such as high altitude and low temperature environments, have an adverse effect on wild fauna survival. However, our results suggested that increasing altitude can enhance some functions in wild sable gut microbial communities. In recent decades, wild sable (Carnivora Mustelidae Martes zibellina) habitats, which are often natural forests, have been squeezed by anthropogenic disturbances such as clear-cutting, tilling and grazing. Sables tend to live in sloped areas with relatively harsh conditions. Here, we determine effects of environmental factors on wild sable gut microbial communities between high and low altitude habitats using Illumina Miseq sequencing of bacterial 16S rRNA genes. Our results showed that despite wild sable gut microbial community diversity being resilient to many environmental factors, community composition was sensitive to altitude. Wild sable gut microbial communities were dominated by Firmicutes (relative abundance 38.23%), followed by Actinobacteria (30.29%), and Proteobacteria (28.15%). Altitude was negatively correlated with the abundance of Firmicutes, suggesting sable likely consume more vegetarian food in lower habitats where plant diversity, temperature and vegetation coverage were greater. In addition, our functional genes prediction and qPCR results demonstrated that energy/fat processing microorganisms and functional genes are enriched with increasing altitude, which likely enhanced metabolic functions and supported wild sables to survive in elevated habitats. Overall, our results improve the knowledge of the ecological impact of habitat change, providing insights into wild animal protection at the mountain area with hash climate conditions.
  • Saarni, Saija; Hartikainen, Samuel; Meronen, Senja; Uurasjarvi, Emilia; Kalliokoski, Maarit; Koistinen, Arto (2021)
    Sediment trapping as a tool to monitor microplastic influx was tested in an urban boreal lake basin. The one-year-long trap monitoring consisted of 5-month and 7-month periods representing growing season and winter season (including the spring flood event), respectively. Sediment accumulation rate (SAR), and organic content were determined, highest SAR - 14.5 g/m(2)/d - was measured during the winter period. Microplastics were extracted from the sediment applying heavy-liquid density separation method and collected under a microscope for further identification with FTIR spectroscopy. PE was identified as the most abundant synthetic polymer type, while PP and PET are also present. The annual microplastic flux rate is 32 400 pieces/m2/ year, and highest accumulation does not coincide with the highest SAR, but occurs during the growing season. Changes in the microplastic accumulation rates are related to seasonal conditions. Highest microplastic concentration with respect to dry sediment weight (10 200 pieces/kg) was observed in a growing season sample, while highest concentration with respect to sediment volume (1800 pieces/l) was observed during winter. This finding underlines the problems related to reporting microplastic concentrations in various units. The results highlight that sediment trap monitoring is an efficient tool for monitoring microplastic accumulation rate in aquatic environments and provides an opportunity to better understand and define processes controlling microplastic accumulation. (C) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license
  • Pozza, Matteo; Rao, Ashwin; Lugones, Diego. F.; Tarkoma, Sasu (2021)
    Network function (NF) developers have traditionally prioritized performance when creating new packet processing capabilities. This was usually driven by a market demand for highly available solutions with differentiating features running at line rate, even at the expense of flexibility and tightly-coupled monolithic designs. Today, however, the market advantage is achieved by providing more features in shorter development cycles and quickly deploying them in different operating environments. In fact, network operators are increasingly adopting continuous software delivery practices as well as new architectural styles (e.g., microservices) to decouple functionality and accelerate development. A key challenge in revisiting NF design is state management, which is usually highly optimized for a deployment by carefully selecting the underlying data store. Therefore, migrating to a data store that suits a different use case is time-consuming as it requires code refactoring and adaptation to new application programming interfaces, APIs. As a result, refactoring NF software for different environments can take up to months, reducing the pace at which new features and upgrades can be deployed in production networks. In this paper, we demonstrate experimentally that it is feasible to introduce an abstraction layer to decouple NF state management from the data store adopted while still approaching line-rate performance. We present FlexState, a state management system that exposes data store functionality as configuration options, which reduces code refactoring efforts. Experiments show that FlexState achieves significant flexibility in optimizing the state management, and accelerates deployment on new scenarios while preserving performance and scalability.
  • Kempa, D. (Society for Industrial and Applied Mathematics, 2019)
    We propose algorithms that, given the input string of length n over integer alphabet of size σ, construct the Burrows–Wheeler transform (BWT), the permuted longest-common-prefix (PLCP) array, and the LZ77 parsing in O(n/ logσ n + r polylog n) time and working space, where r is the number of runs in the BWT of the input. These are the essential components of many compressed indexes such as compressed suffix tree, FM-index, and grammar and LZ77-based indexes, but also find numerous applications in sequence analysis and data compression. The value of r is a common measure of repetitiveness that is significantly smaller than n if the string is highly repetitive. Since just accessing every symbol of the string requires Ω(n/ logσ n) time, the presented algorithms are time and space optimal for inputs satisfying the assumption n/r ∈ Ω(polylog n) on the repetitiveness. For such inputs our result improves upon the currently fastest general algorithms of Belazzougui (STOC 2014) and Munro et al. (SODA 2017) which run in O(n) time and use O(n/ logσ n) working space. We also show how to use our techniques to obtain optimal solutions on highly repetitive data for other fundamental string processing problems such as: Lyndon factorization, construction of run-length compressed suffix arrays, and some classical “textbook” problems such as computing the longest substring occurring at least some fixed number of times. Copyright © 2019 by SIAM
  • Hammid, Anam; Fallon, John K.; Lassila, Toni; Salluce, Giulia; Smith, Philip C.; Tolonen, Ari; Sauer, Achim; Urtti, Arto; Honkakoski, Paavo (2021)
    Hydrolytic reactions constitute an important pathway of drug metabolism and a significant route of prodrug activation. Many ophthalmic drugs and prodrugs contain ester groups that greatly enhance their permeation across several hydrophobic barriers in the eye before the drugs are either metabolized or released, respectively, via hydrolysis. Thus, the development of ophthalmic drug therapy requires the thorough profiling of substrate specificities, activities, and expression levels of ocular esterases. However, such information is scant in the literature, especially for preclinical species often used in ophthalmology such as rabbits and pigs. Therefore, our aim was to generate systematic information on the activity and expression of carboxylesterases (CESs) and arylacetamide deacetylase (AADAC) in seven ocular tissue homogenates from these two species. The hydrolytic activities were measured using a generic esterase substrate (4-nitrophenyl acetate) and, in the absence of validated substrates for rabbit and pig enzymes, with selective substrates established for human CES1, CES2, and AADAC (D-luciferin methyl ester, fluorescein diacetate, procaine, and phenacetin). Kinetics and inhibition studies were conducted using these substrates and, again due to a lack of validated rabbit and pig CES inhibitors, with known inhibitors for the human enzymes. Protein expression levels were measured using quantitative targeted proteomics. Rabbit ocular tissues showed significant variability in the expression of CES1 (higher in cornea, lower in conjunctiva) and CES2 (higher in conjunctiva, lower in cornea) and a poor correlation of CES expression with hydrolytic activities. In contrast, pig tissues appear to express only CES1, and CES3 and AADAC seem to be either low or absent, respectively, in both species. The current study revealed remarkable species and tissue differences in ocular hydrolytic enzymes that can be taken into account in the design of esterase-dependent prodrugs and drug conjugates, the evaluation of ocular effects of systemic drugs, and in translational and toxicity studies.
  • Koch, Natalie; Tynkkynen, Veli-Pekka (2021)
    This article examines recent renewable energy initiatives in two hydrocarbon rich states of Eurasia: Kazakhstan and Russia. The global nature of challenges surrounding energy and natural resource use demand that sustainability and “energy transition” policies be understood as geopolitical issues, which are increasingly (re)defining political relations among and within states. Existing research and media coverage of international energy politics in Eurasia is overwhelmingly dominated by a focus on oil and gas extraction, especially in Kazakhstan and Russia, due to their central place in traditional hydrocarbon fuels markets. As elsewhere in the world, however, political and economic leaders in both countries have started to adopt the language of promoting environmental sustainability, the “green economy,” and renewable energy infrastructures. Taking a critical geopolitics lens to recent developments, this article considers who is involved in advancing renewable energy in contexts that have traditionally been dependent on traditional energy sources, and what this may portend for the shifting energy landscape of Eurasia.
  • Koskinen, Juhani S.; Kytö, Ville; Juonala, Markus; Viikari, Jorma S. A.; Nevalainen, Jaakko; Kähönen, Mika; Lehtimäki, Terho; Hutri-Kähönen, Nina; Laitinen, Tomi; Tossavainen, Päivi; Jokinen, Eero; Magnussen, Costan G.; Raitakari, Olli T. (2020)
    Background and aims: Carotid plaque is a specific sign of atherosclerosis and adults with carotid plaque are at increased risk for cardiovascular outcomes. Atherosclerosis has roots in childhood and pediatric guidelines provide cut-off values for cardiovascular risk factors. However, it is unknown whether these cut-offs predict adulthood advanced atherosclerosis. Methods: The Cardiovascular Risk in Young Finns Study is a follow-up of children that begun in 1980 when 2653 participants with data for the present analyses were aged 3-18 years. In 2001 and 2007 follow-ups, in addition to adulthood cardiovascular risk factors, carotid ultrasound data was collected. Long-term burden, as the area under the curve, was evaluated for childhood (6-18 years) risk factors. To study the associations of guideline-based cut-offs with carotid plaque, both childhood and adult risk factors were classified according to clinical practice guidelines. Results: Carotid plaque, defined as a focal structure of the arterial wall protruding into lumen > 50% compared to adjacent intima-media thickness, was present in 88 (3.3%) participants. Relative risk for carotid plaque, when adjusted for age and sex, was 3.03 (95% CI, 1.76-5.21) for childhood dyslipidemia, 1.51 (95% CI, 0.99-2.32) for childhood elevated systolic blood pressure, and 1.93 (95% CI, 1.26-2.94) for childhood smoking. Childhood dyslipidemia and smoking remained independent predictors of carotid plaque in models additionally adjusted for adult risk factors and family history of coronary heart disease. Carotid plaque was present in less than 1% of adults with no childhood risk factors. Conclusions: Findings reinforce childhood prevention efforts and demonstrate the utility of guideline-based cutoffs in identifying children at increased risk for adulthood atherosclerosis.
  • Vieno, Atte (2021)
    This article examines the effects of the vertical disintegration of production on airport terminal workers through the theoretical lens of occupational belonging, highlighting themes of sensory and embodied experience, changing dynamics of employment relationships, and new patterns of inclusion and exclusion. The article contributes to efforts to produce nuanced empirical accounts of the dynamics of post-Fordist work, showing how restructuring had the effect of disrupting employment relations and activity rhythms, while nevertheless preserving 'the airport' as a symbolic and relational setting in relation to which occupational belonging could be constructed. The article examines how the work of binding people and jobs, previously undertaken by integrated organisations, was taken up by workers themselves through their personal relationships and will to belong. The article highlights the capacity to undertake this work of belonging as a central dynamic of occupational inclusion and exclusion, a capacity which in this empirical context was experienced as being shaped by age and the ability to make use of personal relationships in navigating precarious employment relations. Based on this empirical analysis, the article argues for belonging as a valuable perspective for studies of materiality, symbolic identification and relationality in post-Fordist work.
  • D'Amico, Carmine; Fontana, Flavia; Cheng, Ruoyu; Santos, Hélder A. (2021)
    The current situation, heavily influenced by the ongoing pandemic, puts vaccines back into the spotlight. However, the conventional and traditional vaccines present disadvantages, particularly related to immunogenicity, stability, and storage of the final product. Often, such products require the maintenance of a “cold chain,” impacting the costs, the availability, and the distribution of vaccines. Here, after a recall of the mode of action of vaccines and the types of vaccines currently available, we analyze the past, present, and future of vaccine formulation. The past focuses on conventional formulations, the present discusses the use of nanoparticles for vaccine delivery and as adjuvants, while the future presents microneedle patches as alternative formulation and administration route. Finally, we compare the advantages and disadvantages of injectable solutions, nanovaccines, and microneedles in terms of efficacy, stability, and patient-friendly design.
  • Morrison, Catriona A.; Butler, Simon J.; Robinson, Robert A.; Clark, Jacquie A.; Arizaga, Juan; Aunins, Ainars; Balta, Oriol; Cepak, Jaroslav; Chodkiewicz, Tomasz; Escandell, Virginia; Foppen, Ruud P. B.; Gregory, Richard D.; Husby, Magne; Jiguet, Frederic; Kålås, John Atle; Lehikoinen, Aleksi; Lindström, Ake; Moshøj, Charlotte M.; Nagy, Karoly; Nebot, Arantza Leal; Piha, Markus; Reif, Jiri; Sattler, Thomas; Skorpilova, Jana; Szep, Tibor; Teufelbauer, Norbert; Thorup, Kasper; van Turnhout, Chris; Wenninger, Thomas; Gill, Jennifer A. (2021)
    Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.
  • Junttila, Sofia; Kelly, Julia; Kljun, Natascha; Aurela, Mika; Klemedtsson, Leif; Lohila, Annalea; Nilsson, Mats B.; Rinne, Janne; Tuittila, Eeva-Stiina; Vestin, Patrik; Weslien, Per; Eklundh, Lars (2021)
    Peatlands play an important role in the global carbon cycle as they contain a large soil carbon stock. However, current climate change could potentially shift peatlands from being carbon sinks to carbon sources. Remote sensing methods provide an opportunity to monitor carbon dioxide (CO2) exchange in peatland ecosystems at large scales under these changing conditions. In this study, we developed empirical models of the CO2 balance (net ecosystem exchange, NEE), gross primary production (GPP), and ecosystem respiration (ER) that could be used for upscaling CO2 fluxes with remotely sensed data. Two to three years of eddy covariance (EC) data from five peatlands in Sweden and Finland were compared to modelled NEE, GPP and ER based on vegetation indices from 10 m resolution Sentinel-2 MSI and land surface temperature from 1 km resolution MODIS data. To ensure a precise match between the EC data and the Sentinel-2 observations, a footprint model was applied to derive footprint-weighted daily means of the vegetation indices. Average model parameters for all sites were acquired with a leave-one-out-cross-validation procedure. Both the GPP and the ER models gave high agreement with the EC-derived fluxes (R-2 = 0.70 and 0.56, NRMSE = 14% and 15%, respectively). The performance of the NEE model was weaker (average R-2 = 0.36 and NRMSE = 13%). Our findings demonstrate that using optical and thermal satellite sensor data is a feasible method for upscaling the GPP and ER of northern boreal peatlands, although further studies are needed to investigate the sources of the unexplained spatial and temporal variation of the CO2 fluxes.
  • Mareček, David; Celikkanat, Hande; Silfverberg, Miikka; Ravishankar, Vinit; Tiedemann, Jörg (2020)
  • Kauppi, Katja; Rajala, Ari; Huusela, Erja; Kaseva, Janne; Ruuttunen, Pentti; Jalli, Heikki; Alakukku, Laura; Jalli, Marja (2021)
    The effect of weeds, plant diseases and insect pests on spring barley (Hordeum vulgare) and spring wheat (Triticum aestivum) grain and nutrient yield was examined. Long-term field trial data was used to assess the impact of different pests on grain yield. In the absence of pesticides, fungal diseases caused the largest annual yield-reduction in spring wheat and spring barley, 500 kg ha(-1) on average. Converting yield loss to nutrient yield loss this represented reductions of 8.1 and 9.2 kg ha(-1) in nitrogen and 1.5 and 1.6 kg ha(-1) in phosphorus, respectively. Likewise, it was estimated that weeds decrease the yield of spring barley and spring wheat for 200 kg ha(-1), which means reductions of 3.7 and 3.2 kg ha(-1) in nitrogen and 0.6 kg ha(-1) in phosphorus, respectively. For insect pests yield-reduction in spring barley and spring wheat varied between 418 and 745 kg ha(-1) respectively. However, because bird cherry-oat aphid (Rhopalosiphum padi L.) incidence data was limited, and aphids are highly variable annually, nutrient yield losses caused by insect pests were not included. Based on the current study, the management of weeds, plant diseases and insects maintain cereal crop yield and may thus decrease the environmental risks caused by unutilized nutrients.
  • Arstila, Valtteri; Georgescu, Alexandra L.; Lunn, Daniel; Noreika, Valdas; Falter-Wagner, Christine M.; Pesonen, Henri (2020)
    Essential for successful interaction with the environment is the human capacity to resolve events in time. Typical event timing paradigms are judgements of simultaneity (SJ) and of temporal order (TOJ). It remains unclear whether SJ and TOJ are based on the same underlying mechanism and whether there are fixed thresholds for resolution. The current study employed four visual event timing task versions: horizontal and vertical SJ and TOJ. Binary responses were analysed using multilevel binary regression modelling. Modulatory effects of potential explanatory variables on event timing perception were investigated: (1) Individual factors (sex and age), (2) temporal factors (SOA, trial number, order of experiment, order of stimuli orientation, time of day) and (3) spatial factors (left or right stimulus first, top or bottom stimulus first, horizontal vs. vertical orientation). The current study directly compares for the first time, performance on SJ and TOJ tasks using the same paradigm and presents evidence that a variety of factors and their interactions selectively modulate event timing functions in humans, explaining the variance found in previous studies. We conclude that SJ and TOJ are partially independent functions, because they are modulated differently by individual and contextual variables.