Bioavailability of pesticides in freshwater sediments

In ecological risk assessment standardized sediment toxicity tests are used to predict the hazard of chemicals for sediment-living organisms. Feeding is a prerequisite in these long-term tests to avoid starvation of test organisms. Therefore, added food particles may act as vectors for the test compound. The importance of food particles as vectors, however, is dependent on several factors, for example, sorption and major uptake routes. In this thesis, laboratory experiments on the importance of pesticide sorption and uptake routes for the bioavailability to the midge Chironomus riparius in sediment toxicity test setups were performed. A feeding selectivity study showed that larvae almost exclusively fed on added food particles, and highly neglected sediment particles. Additionally, experiments on the sorption of the insecticide lindane, showed that food and peat particles (used in artificial sediment) efficiently sorbed lindane (>95% after 48 h). The binding strength of lindane was weak, facilitating particulate uptake. However, the uptake from dissolved lindane was higher than the uptake from particles. From this we concluded that toxicity may be underestimated in spiked-sediment scenarios, where hydrophobic pesticides sorb to the sediment and larvae to a large extent feed on uncontaminated food particles. Conversely, in a spiked-water scenario, the food particles may act as vector, resulting in a facilitated particulate uptake, in addition to the uptake from water. Sediment organic matter affects sorption, and thus bioavailability of pesticides. Pyrethroid toxicity was much higher in artificial sediment than in a natural sediment, indicating the simplicity and shortcomings of using artificial sediments. Interestingly, the sediment quality highly affected bioavailability in spiked-water. For example, C. riparus larvae in sediments with low organic matter content and exposed to spiked-water pyrethroids, showed lower survival, slower development, and increased adult size, than those in sediments with higher organic matter. The pyrethroid deltamethrin, showed an LC50-value (28 d) for C. riparius larvae in artificial sediment of 16 pg/L and 11 µg/kg for water- and sediment exposures, respectively, i.e. toxic effects occurred at concentrations lower than the detection limits for high-tech analytical methods. This thesis contributes to a wider understanding of processes affecting bioavailability in freshwater sediments, and in particular in standardized sediments used in toxicity testing. The understanding of test compound sorption and bioavailability is crucial for sound interpretations of toxicity tests and for the general credibility of such tests

Evaporated extracts of samples for pesticide residue analysis simplifies transport from remote places

The increasing use of pesticides demands a world-wide control of residue levels in food and the environment. However, pesticide residue analysis is challenging and needs both experience and instrumentation. Although much can be done with fairly simple means, many countries with limited resources can only perform certain analyses. Also in technologically more advanced countries, different laboratories may specialize in certain kinds of analyses and there is also a need to confirm results with an exchange of samples between laboratories. There are usually several technical difficulties connected with the transport of pesticide samples, in addition to the risk of transmission of pests and diseases and related customs control; and in many areas of the world transport of pesticide samples is not feasible at all. A way to circumvent these difficulties is presented here. Even if a laboratory lacks the basic requirements to purchase, run and maintain instrumentation to analyze pesticide residues, there are often possibilities to extract the pesticide samples. The extracts are taken to dryness in the presence of a ‘keeper’ substance, and the residues can then be sent in apparently empty glass vials. We have investigated the use of polyethylene glycol as a keeper at harsh conditions, for up to three weeks at 44°C. This was done to find out whether the residues remain in the vials at simulated transport conditions. In all, 64 pesticides were tested and of these 56 substances give recoveries of at least 70% after storage at 44°C for 3 weeks. Thus, according to the results it would be possible to send pesticide samples as evaporated extracts even in a hot climate. In conclusion, the results presented here clearly show that a much simplified method of transfer of samples between laboratories is adequate, which enables monitoring of pesticide residues in any part of the world

Подготовка иностранных граждан в клинической ординатуре по урологии

УРОЛОГИЯОРДИНАТУРАОБУЧЕНИЕ ИНОСТРАННЫХ ГРАЖДА

Preschoolers’ use and exploration of concepts related to scientific phenomena in preschool

The study described in this paper concerns science education in preschool, more specifically how young children in preschool settings invent, develop and explore science and scientific concepts in problem-solving and communicative situations. The aim of the paper is to discuss young children´s concept creation and draw conclusions for early science education. The method used was a secondary analysis of empirical material drawn from three previous studies carried out by the authors. Examples of preschool children’s use of language were extracted and was, for the purpose of this study, analyzed with a new focus on children’s use of concepts. The re-analysis draws from Vygotsky’s theoretical framework on children’s conceptual development and appropriation of new concepts (Vygotsky, 1934/1999; Åkerblom 2011) and from the later Wittgenstein (1986) on the role of language meaning in understanding. The findings underline the importance of allowing preschool children to invent, develop and explore science and technology concepts, as well as implications for preschool teachers to create dialogic spaces for the children to do so. The limitations of the study are however that it is based on a limited number of examples and even though it can give implications and point out directions, is not conclusive and should be followed by further research

Children’s understanding of representations of basic chemistry after participating in an early childhood drama pedagogical activity

The purpose of this study is to generate insight into how young children in early childhood science education understand representation. Taking many forms: gestural, material and verbal (Gilbert, 2005), representations are critical to science education, already with young children. The empirical data for our analysis consist of interviews conducted with 6-year-old children after having participated in a playfully-formatted activity (van Oers, 2014) in basic chemistry held at a culture centre for children. The interviews are analyzed as social practice, clarifying how the children respond to the conceptual and communicative challenges they face. The results show that there are important differences in how the children show that they understand the forms of representations used in the activity. What these differences are and why they are critical to developing representational insight and basic scientific understanding, and therefore what educational implications our findings have, are discussed

Living Stories of Care: Exploring Discursive Clashes Through Storytelling by Nurses

Purpose: Nurses constitute a key group to focus on due to their close proximity to the core of health care, the patient. We aim to understand the care discourse in the practice of nursing within public health care organizations, and its coexistence with the current marketization discourse promoted by the New Public Management paradigm. Our intention with this approach is not only to nuance and problematize the research done to date, but to delineate and illustrate what practitioners actually draw upon in their construction of care-giving. Methodology: By avoiding embarking from pre-prepared narratives and focusing on stories evoked in the moment, this study allows important discursive perspectives to naturally emerge. Analyzing the ethics in storytelling creates awareness and new room for an unheard voice, that of the nurse, and explores the nuances inherent therein. Ethics are inextricably connected to the experiences of people. Seen in the light of this, the ambivalent coexistence of care and marketization discourses calls for a need to empirically as well as methodologically nuance the way patients, and interactions with them are conceptualized. A discourse analysis of how an ethics of care is drawn upon will expand the boundaries of our understanding whether a care discourse is dominant, or is being amalgamated by customer ideals. Theoretical perspectives: Implications of New Public Management in health care organizations are introduced. Further, a feminist Ethics of Care is critically discussed, from which three versions are identified: Care as an orientation, care as a practice, and care as a moral framework. A brief overview of Ethics of Care in nursing literature is provided. This provides a theoretical framework to better understand the ethics drawn upon in the storytelling by nurses Empirical foundation: Empirical data in collected through six semi-structured qualitative interviews with nurses with different specializations and experiences, working at five different hospitals within Region Skåne. Further, a discourse analysis of the talks by politicians, hospital managers, and medical practitioners during a seminar held by the Ethics Council of Region Skåne is provided. Conclusions: The study’s knowledge contribution is directed towards the conflicting subject positions embodied in the dichotomy of ‘patient’ and ‘customer’. The empirical results show that the conceptualization of the one cared for (patient) as a ‘customer’, in practice brings few benefits and rather many ponderous problems for both practitioner and said patient. The in policy much professed benefits said to be won by a union between patient and customer ideals are thus nuanced. This in the sense that the thesis has problematized their claimed complementary properties by taking the voices of nurses into account. We argue that emancipating the perspective of nurses by virtue leads to a more nuanced understanding for future research and policy-making efforts. Thus allowing them to be directed towards constructing increased concordance with the practice of care-giving and its inherent ethics

Parempaan kehitysvammaisten asumiseen – Viiden asumisyksikön arviointi

Mikä tekee kehitysvammaisten asumisyksikön asunnosta kodin? Miten asukkaiden yksilöllisten tarpeet otetaan huomioon suunnitteluratkaisuissa? Millaiset kehitysvammaisten asumisyksiköiden suunnittelun ja toteutuksen lähtökohdat tulisi olla? Nämä ovat keskeisiä kysymyksiä viiden 2000-luvun alussa rakennetun kehitysvammaisten asumisyksikön arvioinnissa. Siinä tarkastellaan suunnitteluratkaisuja ja toteutusta sekä arvioidaan niiden toimivuutta asukkaiden ja työntekijöiden näkökulmasta. Tuloksena kehitetään arviointi- ja suunnittelukriteereitä kehitysvammaisten asumisyksiköiden suunnitteluun mm. sijainnin, asuin-, yhteis- ja pihatilojen sekä turvallisuuden osalta. Tutkimuskohteina on viisi erityyppistä asumisyksikköä: asumispalveluryhmät Seinäjoella ja Alahärmässä, Kauniaisten ryhmäkoti, Kesäheinän palvelukoti Kajaanissa sekä Kirkonsalmen palvelukodin autismiyksikkö Iisalmessa. Tutkimusmenetelminä käytettiin kohteiden havainnoita, kyselyjä asukkaiden omaisille sekä henkilökunnalle. Asukkaiden teemahaastattelujen avulla kerättiin tietoa asumiseen liittyvistä odotuksista ja asumisen sujumisesta. Suunnittelijoille ja toteuttajille suunnatulla kyselyllä kartoitettiin erityisasumiskohteiden toteutusta, ja etenkin tavanomaisesta asuntorakentamiskohteesta poikkeavia tekijöitä. Asumisyksiköiden toimintojen tilantarpeiden määrittelyssä todettiin selvää niukkuutta. Tilat olivat suurelta osin riittämättömät erityisesti apuvälineitä käyttävien ja avustavien toimien kannalta. Sijaintiin oltiin tyytyväisiä ja yksiköitä pidettiin turvallisina asuinpaikkoina. Kohteiden tilat eivät vastanneet kuitenkaan riittävästi esteettömyysvaatimuksia. Tarvitaankin erilaisia asumisratkaisuja tarvitaan, jotta asukkaiden yksilöllisiä vaatimuksia voidaan toteuttaa

Dolda arenor för (re)produktion av ett alternativt ledarskap?

I svenska folkrörelser diskuteras idag det egna ledarskapet och hur detta kan utvecklas och förnyas. Inom organisationerna söker förtroendevalda och högre tjänstemän efter nya former och metoder, perspektiv och förhållningssätt, för att försöka förstå och vidareutveckla ledning och organisering av både traditionella verksamheter och nya aktiviteter. De sneglar på de ’rationella’ modeller och styrsystem som de tror finns i näringslivet och söker inspiration från offentlig förvaltning. Samtidigt pågår en process bland företagen, där företagsledare och konsulter söker nya vägar. Det talas om det visionära ledarskapet, om corporate religion eller om vikten av att företagen har ett humanistiskt ledarskap som är baserat på etiska principer och medmänsklighet. Gemensamma värderingar tycks vara något av en nyckel till framgångsrikt ledarskap i morgondagens näringsliv. Inom den offentliga sektorn har såväl kommuner som landsting blivit företagiserade i rasande fart under de två senaste decennierna, och såväl marknadstänkande som affärsmannaskap har införts på många håll. Olika former av köp–sälj-system är numera legio, och modeller där ’medborgaren är kund’ drivs med emfas. Folkrörelser och andra ideella organisationer har relationer till båda dessa typer av verksamhet. I denna turbulens föddes vårt projekt.popular movement; adult education; leadership; discourse analysis; Sweden

Functional Studies of microRNAs in Neural Stem Cells: Problems and Perspectives

In adult mammals, neural stem cells (NSCs) are found in two niches of the brain; the subventricular zone by the lateral ventricles and the subgranular zone of the dentate gyrus in the hippocampus. Neurogenesis is a complex process that is tightly controlled on a molecular level. Recently, microRNAs (miRNAs) have been implicated to play a central role in the regulation of NCSs. miRNAs are small, endogenously expressed RNAs that regulate gene expression at the post-transcriptional level. However, functional studies of miRNAs are complicated due to current technical limitations. In this review we describe recent findings about miRNAs in NSCs looking closely at miR-124, miR-9, and let-7. In addition, we highlight technical strategies used to investigate miRNA function, accentuating limitations, and potentials