The effect of different mulches on the growth and yield of organically grown strawberry

Different mulches were studied in field trials over a three-year period under organic production in Mikkeli and Ruukki. The mulching materials were black plastic, flax fibre mat (woodchips+buckwheat husk in 2002), green mass, straw, buckwheat husk, birch woodchips and pine woodchips

Diel patterns and tissue-specificity of environmental responses in fish

Humans are profoundly changing aquatic environments through climate change and the release of nutrients and chemicals. To understand the effects of these changes on natural populations, knowledge on individuals’ environmental responses is needed. At the molecular level, the environmental responses are partly mediated by chances in messenger RNA and protein levels. In this thesis I study messenger RNA and protein responses to an assortment of environmental stressors in fish. As daily (diel) rhythms are known to be ubiquitous in different tissues, I particularly focus on diel patterns in the responses. The studied species are the three-spined stickleback (Gasterosteus aculeatus L.) and the Arctic char (Salvelinus alpinus L.), both of which have circumpolar distribution in the Northern hemisphere. In the first two studies, three-spined sticklebacks were exposed to both the non-steroidal anti-inflammatory drug diclofenac and low-oxygen conditions (hypoxia), and their responses measured at separate time points in the liver and gills. The results show how the seemingly unrelated environmental stressors, hypoxia and anti-inflammatory drugs, can have harmful combined effects that differ from the effects of each stressor alone. Moreover, both stressors disturbed natural diel patterns in gene expression. In the third study, I studied the responses of three-spined sticklebacks to two test chemicals: one used in hormonal medicine (17α-ethinyl-oestradiol) and one used as a plasticizer and solvent chemical (di-n-butyl phthalate). The results suggest that the phthalate can affect genes related to spermatogenesis in fish testes, while estrogen-mimicking compounds can lead to numerous disturbances in the endocrine system. In the final study, the temperature-dependence of diel rhythms in messenger RNA levels were evaluated in the liver tissue of the Arctic char, a cold-adapted salmonid. The results show that cold acclimation repressed diel rhythms in gene expression compared to warm-acclimated fish, in which the expression of hundreds of genes was rhythmic, suggesting the circadian clock of the Arctic fish species can be sensitive to temperature. Overall, the results of the thesis indicate that fishes’ responses to abiotic factors interact with their diel rhythms, and more studies on the consequences of these interactions are needed to comprehensively understand human impacts on ecosystems.Ihmistoiminnan tuottamat kasvihuonekaasut sekä kemikaali- ja ravinnepäästöt muuttavat ympäristöä voimakkaasti. Muutosten vaikutusten ymmärtämiseksi tarvitsemme tietoa eri lajien ympäristövasteista. Molekyylitasolla vasteita säätelevät proteiinit, joiden määrä soluissa on osin riippuvainen tuotetun lähetti-RNA:n määrästä. Tässä väitöskirjassa käsittelen eri ympäristömuutosten vaikutuksia kaloihin lähetti-RNA:n määrän ja entsyymiaktiivisuuden tasolla eri kudoksissa. Vuorokausirytmien tiedetään säätelevän monien geenien ilmenemistä, joten keskityin etenkin ajalliseen vaihteluun kalojen ympäristövasteissa. Tutkitut kalalajit olivat lauhkeaan ilmastoon sopeutunut kolmipiikki (Gasterosteus aculeatus L.) ja arktisiin olosuhteisiin sopeutunut nieriä (Salvelinus alpinus L.). Kummatkin lajit elävät laajoilla alueilla pohjoisella pallonpuoliskolla. Kahdessa ensimmäisessä työssä testasin kolmipiikkien vasteita jätevesissä esiintyvälle tulehduskipulääke diklofenaakille ja vähähappisille olosuhteille (hypoksialle). Maksa- ja kiduskudoksista saadut tulokset osoittavat hypoksialla ja diklofenaakilla olevan mahdollisesti haitallisia yhteisvaikutuksia kaloihin, ja että kiduksissa ja maksassa tapahtuvat muutokset voivat olla erisuuntaisia. Sekä diklofenaakin että hypoksian havaittiin myös muuttavan entsyymien luontaista päivärytmiä. Kolmannessa osatyössä tutkin kolmipiikkien vasteita kahdelle hormonitoimintaa häiritseville yhdisteelle, keinotekoiselle estradiolille sekä muoviyhdisteissä käytetylle dibutyyliftalaatille. Havaitsin ftalaatin vaikuttavan siittiöiden toimintaa säätelevien geenien luentaan ja estradiolin estävän useiden steroidihormonien tuotantoa säätelevien geenien ilmenemistä kalojen sukuelimissä. Viimeisessä osatyössä tutkin lämpenemisen vaikutuksia geeniluennan päivärytmiin lohikaloihin kuuluvalla nieriällä. Tulokset osoittivat, että korkeassa lämpötilassa nieriän geenien luenta vaihteli voimakkaasti päivän aikana, mutta viileässä lämpötilassa vaihtelu oli huomaamatonta, mikä viittaa siihen, että arktisten kalojen biologinen kello voi olla herkkä lämpötilamuutoksille. Kokonaisuudessaan väitöskirjan tulokset osoittavat, että meidän on vaikea ennustaa ympäristömuutosten yhteisvaikutuksia luonnon populaatioihin, jos emme ymmärrä ympäristövasteiden ja biologisten rytmien vuorovaikutuksia.Siirretty Doriast

Chemical aspects of peracetic acid based wastewater disinfection

Peracetic acid (PAA) has been studied for wastewater disinfection  applications for some 30 years and has been shown to be an effective disinfectant against many indicator microbes, including bacteria, viruses, and protozoa. One of the key advantages compared to, e.g., chlorine is the lack of harmful disinfection by-products. In this paper a pilot-scale study of PAA-based disinfection is presented. Indicator microbes (E. coli, total coliforms and coliphage viruses) as well as chemical parameters (pH, oxidation-reduction potential (ORP), chemical and biochemical oxygen  demand (COD and BOD), and residual PAA and hydrogen peroxide) were studied. The main aim of this investigation was to study how these  selected chemical parameters change during PAA treatment. Based on the results, disinfection was efficient at C·t values of 15 to 30 (mg·min)/l which equals to a PAA dose of 1.5 to 2 mg/l and a contact time of 10 to 15 min. In this concentration area changes in pH, COD and BOD were negligible. However, hydrogen peroxide residues may interfere with COD   measurements and apparent COD can be higher than the calculated   theoretical oxygen demand (ThOD). Additionally PAA or hydrogen peroxide residues interfere with the BOD test resulting in BOD values that are too  low. Residual PAA and ORP were found to correlate with remaining amounts of bacteria.Keywords: tertiary wastewater disinfection, peracetic acid, total coliform, E. coli, coliphage

Käykö katteeksi? Muovin vaihtoehtoja luomumansikalla

MTT:ssä tutkitaan perinteisen mansikkamuovin rinnalla orgaanisia maanpinnan katteita. Tutkimushankkeessa selvitetään, miten erilaiset katteet toimivat ja millaisia eroja niissä on. Lisäksi tutkitaan, miten katteet vaikuttavat sadon säilymiseen, marjojen mikrobiologiseen laatuun ja mansikkapunkkiin.vokEKO/Karil

Comparison Study of Manometric Respirometric Test and Common Chemical Methods in the Determination of BOD bold7 in a Pulp and Paper Mill's Wastewaters

The biological oxygen demand (BOD) test is widely used in many wastewater treatment plants. The conventional BOD tests are usually time-consuming and the results are often out of date for process control purposes. The aim of this research was to compare the manometric respirometric test with common chemical methods in the determination of BOD of wastewater from a pulp and paper mills as well as to evaluate the BOD 7 values of both wastewaters from the short-term respirometric measurements. The results showed that there were differences in the BOD7 values of paper mill samples measured by conventional and respirometric methods. The main cause was found to be the dilution solution used in the conventional BOD tests. Using the same mineral solution in the respirometric measurements diminished the difference remarkably. Evaluation of the BOD7 value after two or three days incubation was proved to work very well and the estimated results were close to measured values (deviations 1%–12%)

Circadian rhythms and environmental disturbances–underexplored interactions

Biological rhythms control the life of virtually all organisms, impacting numerous aspects ranging from subcellular processes to behaviour. Many studies have shown that changes in abiotic environmental conditions can disturb or entrain circadian (∼24 h) rhythms. These expected changes are so large that they could impose risks to the long-term viability of populations. Climate change is a major global stressor affecting the fitness of animals, partially because it challenges the adaptive associations between endogenous clocks and temperature – consequently, one can posit that a large-scale natural experiment on the plasticity of rhythm–temperature interactions is underway. Further risks are posed by chemical pollution and the depletion of oxygen levels in aquatic environments. Here, we focused our attention on fish, which are at heightened risk of being affected by human influence and are adapted to diverse environments showing predictable changes in light conditions, oxygen saturation and temperature. The examined literature to date suggests an abundance of mechanisms that can lead to interactions between responses to hypoxia, pollutants or pathogens and regulation of endogenous rhythms, but also reveals gaps in our understanding of the plasticity of endogenous rhythms in fish and in how these interactions may be disturbed by human influence and affect natural populations. Here, we summarize research on the molecular mechanisms behind environment–clock interactions as they relate to oxygen variability, temperature and responses to pollutants, and propose ways to address these interactions more conclusively in future studies.</p

La frontera finlandesa-sueca, las movilidades y la geopolítica de la resiliencia

Aquest article analitza el potencial del concepte de resiliència per a la recerca des de la geopolítica crítica en el context de la frontera interna entre Finlàndia i Suècia a la Unió Europea. L'examen se centra en la geopolítica quotidiana de la resiliència, manifestada en la política d'adaptació/no adaptació als requisits estatals, i en dos dels principals esdeveniments fronterers que han tingut un impacte considerable en les institucions frontereres i en la vida de les persones a la frontera: primer, la intervenció de la frontera estatal durant el "llarg estiu de la migració" europeu de 2015 i, en segon lloc, la pandèmia de Covid-19 a la qual Finlàndia va respondre amb una regulació estricta, mentre que Suècia va continuar amb una política de fronteres obertes. El material de l'estudi es va recopilar a través de la realització de treball de camp i entrevistes en la zona fronterera entre Finlàndia i Suècia, i dels mitjans de comunicació finlandesos i suecs. Tots dos casos brinden un exemple d'una ràpida intervenció fronterera i de securitizació.This article scrutinizes the potential of the resilience concept for critical geopolitical research in the EU-internal Finnish-Swedish border context. The examination focuses on the everyday geopolitics of resilience – manifested in the politics of adaptation/non-adaptation towards state based requirements – and the two major border events that have had a considerable impact on the border institution and the lives of borderland people: first, the state border intervention during the 2015 European “long summer of migration” and second, the Covid-19 pandemic that Finland responded with strict regulation whereas Sweden continued an open border policy. The material of the study was collected by conducting fieldwork and interviews in the Finnish-Swedish border area and from the Finnish and Swedish media.  Both cases provide an example of a rapid border intervention and securitization.Este artículo analiza el potencial del concepto de resiliencia para la investigación desde la geopolítica crítica en el contexto de la frontera interna entre Finlandia y Suecia en la Unión Europea. El examen se centra en la geopolítica cotidiana de la resiliencia, manifestada en la política de adaptación/no adaptación a los requisitos estatales, y en dos de los principales eventos fronterizos que han tenido un impacto considerable en las instituciones fronterizas y en la vida de las personas en la frontera: primero, la intervención de la frontera estatal durante el "largo verano de la migración" europeo de 2015 y, en segundo lugar, la pandemia de Covid-19 a la que Finlandia respondió con una regulación estricta, mientras que Suecia continuó con una política de fronteras abiertas. El material del estudio se recopiló a través de la realización de trabajo de campo y entrevistas en la zona fronteriza entre Finlandia y Suecia, y de los medios de comunicación finlandeses y suecos. Ambos casos brindan un ejemplo de una rápida intervención fronteriza y de securitización.

Standard metabolic rate does not associate with age-at-maturity genotype in juvenile Atlantic salmon

Atlantic salmon (Salmo salar) is a species with diverse life-history strategies, to which the timing of maturation contributes considerably. Recently, the genome region including the gene vgll3 has gained attention as a locus with a large effect on Atlantic salmon maturation timing, and recent studies on the vgll3 locus in salmon have indicated that its effect might be mediated through body condition and accumulation of adipose tissue. However, the cellular and physiological pathways leading from vgll3 genotype to phenotype are still unknown. Standard metabolic rate is a potentially important trait for resource acquisition and assimilation and we hypothesized that this trait, being a proxy for the maintenance energy expenditure of an individual, could be an important link in the pathway from vgll3 genotype to maturation timing phenotype. As a first step to studying links between vgll3 and the metabolic phenotype of Atlantic salmon, we measured the standard metabolic rate of 150 first-year Atlantic salmon juveniles of both sexes, originating from 14 different families with either late-maturing or early-maturing vgll3 genotypes. No significant difference in mass-adjusted standard metabolic rate was detected between individuals with different vgll3 genotypes, indicating that juvenile salmon of different vgll3 genotypes have similar maintenance energy requirements in the experimental conditions used and that the effects of vgll3 on body condition and maturation are not strongly related to maintenance energy expenditure in either sex at this life stage.Peer reviewe