Quarantine and surveillance strategies for plant pathogen detection and control

Incursions of plant pests and diseases pose serious threats to food security, agricultural productivity and the natural environment. One of the challenges in confidently delimiting and eradicating incursions is how to choose from an arsenal of surveillance and quarantine approaches in order to best control multiple dispersal pathways. Anthropogenic spread (propagules carried on humans or transported on produce or equipment) can be controlled with quarantine measures, which in turn can vary in intensity. In contrast, environmental spread processes are more difficult to control, but often have a temporal signal (e.g. seasonality) which can introduce both challenges and opportunities for surveillance and control. This leads to complex decisions regarding when, where and how to search. Recent modelling investigations of surveillance performance have optimised the output of simulation models, and found that a risk-weighted randomised search can perform close to optimally. However, exactly how quarantine and surveillance strategies should change to reflect different dispersal modes remains largely unaddressed. Here we develop a spatial simulation model of a plant fungal-pathogen incursion into an agricultural region, and its subsequent surveillance and control. We include structural differences in dispersal via the interplay of biological, environmental and anthropogenic connectivity between host sites (farms). Our objective was to gain broad insights into the relative roles played by different spread modes in propagating an invasion, and how incorporating knowledge of these spread risks may improve approaches to quarantine restrictions and surveillance. We find that broad heuristic rules for quarantine restrictions fail to contain the pathogen due to residual connectivity between sites, but surveillance measures enable early detection and successfully lead to suppression of the pathogen in all farms. Alternative surveillance strategies attain similar levels of performance by incorporating environmental or anthropogenic dispersal risk in the prioritisation of sites. Our model provides the basis to develop essential insights into the effectiveness of different surveillance and quarantine decisions for fungal pathogen control. Parameterised for authentic settings it will aid our understanding of how the extent and resolution of interventions should suitably reflect the spatial structure of dispersal processes.

Predicting the temporal response of seagrass meadows to dredging using Dynamic Bayesian Networks

Predicting temporal responses of ecosystems to disturbances associated with industrial activities is critical for their management and conservation. However, prediction of ecosystem responses is challenging due to the complexity and potential non-linearities stemming from interactions between system components and multiple environmental drivers. Prediction is particularly difficult for marine ecosystems due to their often highly variable and complex natures and large uncertainties surrounding their dynamic responses. Consequently, current management of such systems often rely on expert judgement and/or complex quantitative models that consider only a subset of the relevant ecological processes. Hence there exists an urgent need for the development of whole-of-systems predictive models to support decision and policy makers in managing complex marine systems in the context of industry based disturbances. This paper presents Dynamic Bayesian Networks (DBNs) for predicting the temporal response of a marine ecosystem to anthropogenic disturbances. The DBN provides a visual representation of the problem domain in terms of factors (parts of the ecosystem) and their relationships. These relationships are quantified via Conditional Probability Tables (CPTs), which estimate the variability and uncertainty in the distribution of each factor. The combination of qualitative visual and quantitative elements in a DBN facilitates the integration of a wide array of data, published and expert knowledge and other models. Such multiple sources are often essential as one single source of information is rarely sufficient to cover the diverse range of factors relevant to a management task. Here, a DBN model is developed for tropical, annual Halophila and temperate, persistent Amphibolis seagrass meadows to inform dredging management and help meet environmental guidelines. Specifically, the impacts of capital (e.g. new port development) and maintenance (e.g. maintaining channel depths in established ports) dredging is evaluated with respect to the risk of permanent loss, defined as no recovery within 5 years (Environmental Protection Agency guidelines). The model is developed using expert knowledge, existing literature, statistical models of environmental light, and experimental data. The model is then demonstrated in a case study through the analysis of a variety of dredging, environmental and seagrass ecosystem recovery scenarios. In spatial zones significantly affected by dredging, such as the zone of moderate impact, shoot density has a very high probability of being driven to zero by capital dredging due to the duration of such dredging. Here, fast growing Halophila species can recover, however, the probability of recovery depends on the presence of seed banks. On the other hand, slow growing Amphibolis meadows have a high probability of suffering permanent loss. However, in the maintenance dredging scenario, due to the shorter duration of dredging, Amphibolis is better able to resist the impacts of dredging. For both types of seagrass meadows, the probability of loss was strongly dependent on the biological and ecological status of the meadow, as well as environmental conditions post-dredging. The ability to predict the ecosystem response under cumulative, non-linear interactions across a complex ecosystem highlights the utility of DBNs for decision support and environmental management.

DNA-induced conformational changes in RecA protein. Evidence for structural heterogeneity among nucleoprotein filaments and implications for homologous pairing

We have used circular dichroism as a probe to characterize the solution conformational changes in RecA protein upon binding to DNA. This approach revealed that RecA protein acquires significant amounts of alpha-helix upon interaction with DNA. These observations, consistent with the data from crystal structure (Story, R. M., Weber, I., and Steitz, T. (1992) Nature 355, 318-325), support the notion that some basic domains including the DNA binding motifs of RecA protein are unstructured and might contribute to the formation of alpha-helix. A comparison of nucleoprotein filaments comprised of RecA protein and a variety of DNA substrates revealed important structural heterogeneity. The most significant difference was observed with poly(dG). poly(dC) and related polymers, rich in GC sequences, which induced minimal amounts of alpha-helix in RecA protein. The magnitude of induction of alpha-helix in RecA protein, which occurred concomitant with the production of ternary complexes, was 2-fold higher with homologous than heterologous duplex DNA. Most importantly, the stimulation of ATP hydrolysis by high salt coincided with that of the induction of alpha-helix in RecA protein. These conformational differences provide a basis for thinking about the biochemical and structural transitions that RecA protein experiences during the formal steps of presynapsis, recognition, and alignment of homologous sequences.

Drop impact on a solid surface comprising micro groove structure

Spreading and receding processes of water drops impacting on a stainless steel surface comprising rectangular shaped parallel grooves are studied experimentally. The study was confined to the impact of drops in inertia dominated flow regime with Weber number in the range 15 - 257. Measurements of spreading drop diameter and drop height were obtained during the impact process as function of time. Experimental measurements of spreading drop diameter and drop height obtained for the grooved surface were compared with those obtained for a smooth surface to elucidate the influence of surface grooves on the impact process. The grooves definitely influence both spreading and receding processes of impacting liquid drops. A more striking observation from this study is that the receding process of impacting liquid drops is dramatically changed by the groove structure for all droplet Weber number.

Kuka kasvattaa, kuka opettaa? : Genealoginen tutkimus perheen ja koulun välisen kasvatusvastuun politiikasta

FAMILIES AND SCHOOLS AND THE POLITICS OF RESPONSIBILITIES - a genealogical study on family and school as carers and educators of the child population in modern society This study aims to uncover the politics behind such discourses in the media which have claimed the family to be totally responsible for children and which ignore the various responsibilities accorded to the state in matters concerning the child population. Using Max Weber s and Michael Mann s theorizing on the history of power relationships, feminist social history on patriarchy and Foucauldian power analytic concept of dispositif the study traces two competing child policies which have influenced the historical formation of modern generational order in Western societies. One of them is based on the interests of the hegemonic bourgeois elite and the other on the interests of the non-elite population, which were expressed during the phase of building the welfare state in Finland in the 1960 1980 s. The central strategies of the bourgeois child policy are 1) to construct the childhood years as a time for preparation and formation of the individual according to the interests of the elite, 2) to construct the family as the sole site of holistic care and responsibility of children in society, and 3) compulsory schooling of children of the non-elite population in state organized schools. To implement these strategies the elite uses strategically patriarchal cultural formations/dispositifs in modernized versions. The result has been the formation of a sexually divided and hierarchical order of care and education, where, on the one hand, there is the less important feminine care of children done by mothers at home and, on the other, the real education of the school, where children are made the object of authoritarian shaping and where the needs and the personal experiences of the child are ignored. The welfare order of care and education is based on the ethos of welfare society, where the state and the families are seen to share the responsibility for the child population. In this vein, families and schools are seen as partners who both have a caring attitude to children s welfare and learning. The study shows that discourses and terminology in the mainstream educational policy texts in Finland create a chaotic linguistic game which makes it difficult to have a rational discussion about the roles of family and school in the holistic care and education of children. This has opened the door to political discourses where familist interpretations of the question of responsibility are claimed to be based on law.

Sairaanhoitajat työn imussa? Palkkatyön sisällön ja kulttuuristen lähtökohtien tasapainossa

Tutkimuksen tavoitteena on selvittää, mikä saa pitkän työuran tehneet sairaanhoitajat innostumaan työstään. Taustalla on yhteiskunnallinen tilanne, jossa työelämän vetovoimaisuuden lisääminen ja ikääntyvien työntekijöiden työssä jaksaminen ovat keskeisiä poliittisia tavoitteita. Aihetta lähestytään positiivisesta psykologiasta lähtöisin olevan työn imun käsitteen avulla. Se on määritelty pysyväksi, ”myönteiseksi, tunne- ja motivaatiotäyttymyksen tilaksi, jota luonnehtivat tarmokkuus, omistautuminen ja uppoutuminen työhön” (Hakanen 2009a, 9). Tutkimuksessa kysytään, voidaanko työn imua ymmärtää myös sosiologisesta näkökulmasta. Oletuksena on, että käsitteen taustalla on muutakin kuin psykologisesta perinteestä käsin jäsentyvää vaihtelua. Empiirisen aineiston muodostavan 11 sairaanhoitajan koko työuraa ja nykyistä työtä koskevat tiettyihin teemoihin ankkuroidut syvähaastattelut. Otosta poimittaessa on etsitty sellaisia haastateltavia, jotka kokevat kantavansa työn imua. Aineiston analyysitapana on käytetty matriisin avulla sovellettua kvalitatiivista sisällönanalyysiä. Työn imua hahmotetaan analyysissä henkilöhistoriallisten haastatteluiden – menneen, nykyisen ja tulevan – kautta. Pyrkimyksenä on etsiä tarinoita mahdollisesti yhdistävää kulttuurista muotoa ja ymmärtää, mihin se perustuu. Analyysin nojalla vastuurationaalisuuden käsite (esim. Korvajärvi 1986) näyttäisi jäsentävän osan haastateltavien suhteesta työhönsä. Avain työn imun löytymiseen näissä tarinoissa on kuitenkin se, kuinka haastateltavilla on ollut henkilökohtainen halu mennä eteenpäin ja kykyä ratkaista ongelmia työuransa aikana ja nykyisessä työssään. Tämä havainto tulkitaan Max Weberin (1922, 1980) käsitteiden – arvorationaalisen ja päämäärärationaalisen toiminnan väliseen suhteen – avulla. Tulokseksi syntyy oletus siitä, että analyysin kohteena olevissa tarinoissa on kyse yhteisestä kulttuurisesta tarinasta siitä, millainen on hyvä ihminen, miten hyvä ihminen toteuttaa itseään työssä ja miten hän tekee työtään: tarmokkaasti, omistautuen ja uppoutuen. Henkilökohtainen halu mennä eteenpäin ja kyky ratkaista ongelmia nojaa sairaanhoitajien erityiseen eetokseen, kutsumustyöhön ja hoivan moraaliin tavalla, joka on rakenteellisesti yhtäläinen protestanttisuutta leimaavan yksilöllisen jumalasuhteen kanssa. Lisäksi analyysin perusteella esitetään, että työn imun edellytys on arvorationaalisen eetoksen lisäksi oikeanlainen, riittävät työn voimavarat sisältävä ympäristö, jossa hoitotyön keskeiset palkinnot on mahdollista saavuttaa. Tällöin palkkatyön sisältö kohtaa kulttuuriset lähtökohdat, ja tulos näkyy työn imuna. Keskeisimmät taustoittavat lähteet ovat Henriksson, Lea & Wrede, Sirpa (toim.) (2004a). Hyvinvointityön ammatit ja Hakanen, Jari (2009a). Työn imun arviointimenetelmä (Utrecht Work Engagement Scale). Sosiologisen tulkinnan kannalta tärkein teoreettinen lähde on Weber, Max (1980): Protestanttinen etiikka ja kapitalismin henki.

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.

Functional role of the Mso1p-Sec1p complex in membrane fusion regulation

Sec1/Munc18 (SM) protein family members are evolutionary conserved proteins. They perform an essential, albeit poorly understood function in SNARE complex formation in membrane fusion. In addition to the SNARE complex components, only a few SM protein binding proteins are known. Typically, their binding modes to SM proteins and their contribution to the membrane fusion regulation is poorly characterised. We identified Mso1p as a novel Sec1p interacting partner. It was shown that Mso1p and Sec1p interact at sites of polarised secretion and that this localisation is dependent on the Rab GTPase Sec4p and its GEF Sec2p. Using targeted mutagenesis and N- and C-terminal deletants, it was discovered that the interaction between an N-terminal peptide of Mso1p and the putative Syntaxin N-peptide binding area in Sec1p domain 1 is important for membrane fusion regulation. The yeast Syntaxin homologues Sso1p and Sso2p lack the N-terminal peptide. Our results show that in addition to binding to the putative N-peptide binding area in Sec1p, Mso1p can interact with Sso1p and Sso2p. This result suggests that Mso1p can mimic the N-peptide binding to facilitate membrane fusion. In addition to Mso1p, a novel role in membrane fusion regulation was revealed for the Sec1p C-terminal tail, which is missing in its mammalian homologues. Deletion of the Sec1p-tail results in temperature sensitive growth and reduced sporulation. Using in vivo and in vitro experiments, it was shown that the Sec1p-tail mediates SNARE complex binding and assembly. These results propose a regulatory role for the Sec1p-tail in SNARE complex formation. Furthermore, two novel interaction partners for Mso1p, the Rab GTPase Sec4p and plasma membrane phospholipids, were identified. The Sec4p link was identified using Bimolecular Fluorescence Complementation assays with Mso1p and the non-SNARE binding Sec1p(1-657). The assay revealed that Mso1p can target Sec1p(1-657) to sites of secretion. This effect is mediated via the Mso1p C-terminus, which previously has been genetically linked to Sec4p. These results and in vitro binding experiments suggest that Mso1p acts in cooperation with the GTP-bound form of Sec4p on vesicle-like structures prior to membrane fusion. Mso1p shares homology with the PIP2 binding domain of the mammalian Munc18 binding Mint proteins. It was shown both in vivo and in vitro that Mso1p is a phospholipid inserting protein and that this insertion is mediated by the conserved Mso1p amino terminus. In vivo, the Mso1p phospholipid binding is needed for sporulation and Mso1p-Sec1p localisation at the sites of secretion at the plasma membrane. The results reveal a novel layer of membrane fusion regulation in exocytosis and propose a coordinating role for Mso1p in connection with membrane lipids, Sec1p, Sec4p and SNARE complexes in this process.

Assessment of Nanoscience and Nanotechnology Initiatives in India

Nanotechnology is a new technology which is generating a lot of interest among academicians, practitioners and scientists. Critical research is being carried out in this area all over the world.Governments are creating policy initiatives to promote developments it the nanoscale science and technology developments. Private investment is also seeing a rising trend. Large number of academic institutions and national laboratories has set up research centers that are workingon the multiple applications of nanotechnology. Wide ranges of applications are claimed for nanotechnology. This consists of materials, chemicals, textiles, semiconductors, to wonder drug delivery systems and diagnostics. Nanotechnology is considered to be a next big wave of technology after information technology and biotechnology. In fact, nanotechnology holds the promise of advances that exceed those achieved in recent decades in computers and biotechnology. Much interest in nanotechnology also could be because of the fact that enormous monetary benefits are expected from nanotechnology based products. According to NSF, revenues from nanotechnology could touch $ 1 trillion by 2015. However much of the benefits are projected ones. Realizing claimed benefits require successful development of nanoscience andv nanotechnology research efforts. That is the journey of invention to innovation has to be completed. For this to happen the technology has to flow from laboratory to market. Nanoscience and nanotechnology research efforts have to come out in the form of new products, new processes, and new platforms.India has also started its Nanoscience and Nanotechnology development program in under its 10(th) Five Year Plan and funds worth Rs. One billion have been allocated for Nanoscience and Nanotechnology Research and Development. The aim of the paper is to assess Nanoscience and Nanotechnology initiatives in India. We propose a conceptual model derived from theresource based view of the innovation. We have developed a structured questionnaire to measure the constructs in the conceptual model. Responses have been collected from 115 scientists and engineers working in the field of Nanoscience and Nanotechnology. The responses have been analyzed further by using Principal Component Analysis, Cluster Analysis and Regression Analysis.

An Expenditure-Based Estimation of Self-Employment Income Underreporting in Finland

This paper estimates the extent of income underreporting by the self-employed in Finland using the expenditure based approach developed by Pissarides & Weber (1989). Household spending data are for the years 1994 to 1996. The results suggest that self-employment income in Finland is underreported by some 27% on average. Since income for the self-employed is about 8 % of all incomes in Finland, the size of this part of the black economy in Finland is estimated to be about 2,3% of GDP.

"Helvetti on kiistaton, mutta taivas on suhteellinen." : Uskonnollisten ihanteiden ja kokemuksen välinen ristiriita L. M. Montgomeryn elämässä vuosina 1921 1927

Tässä tutkimuksessa tutkittiin kanadalaisen kirjailijan L. M. Montgomeryn (1874 1942) elämää vuosina 1921 1927. Kyseisinä vuosina Montgomery eli presbyteeripapin vaimona maaseutuseurakunnissa, ensin Leaskdalessa ja sitten Norvalissa Kanadan Ontariossa. Tutkimus keskittyi tarkastelemaan kirjailijan elämää hallinnutta ristiriitaa, joka muodostui uskonnollisten ihanteiden ja yksilöllisen kokemuksen välisistä eroavaisuuksista. Primäärilähteinä olivat Montgomeryn toimitetut ja julkaistut päiväkirjat The Selected Journals of L. M. Montgomery 1 5 (1985 2004), joista käytettiin etenkin tutkimusvuosiin keskittyvää kolmatta osaa, Montgomeryn neljä romaania Emily of New Moon (1923), Emily Climbs (1925), Blue Castle (1926) ja Emily's Quest (1927) sekä Montgomeryn toimitettu ja julkaistu kirjeenvaihto After Green Gables: L. M. Montgomery's Letters to Ephraim Weber , 1916 1941 (2006) ja My Dear Mr. M.: Letters to G. B. MacMillan (1980). Lisäksi lähteinä oli Leaskdalen seurakuntalaisten kokoama muistelmateos Montgomerysta. Kirjallisuutta käytettiin kirkkohistorian, kirjallisuudentutkimuksen ja naistutkimuksen alalta. Suositusta kirjailijasta on tehty useampia elämäkertoja ja niitä hyödynnettiin tutkimuksessa. Tutkimus jakautui kahteen päälukuun, jotka toimivat toistensa vastaparina. Ensimmäinen tutkimusluku keskittyi tarkastelemaan uskonnollisia ja viktoriaanisia ihanteita, joiden mukaisesti Montgomery oli saanut kasvatuksen. Hän pyrki täyttämään näitä ihanteita myös pappilan emäntänä. Toinen tutkimusluku tarkasteli kirjailijan elämää, uskonnollisia ajatuksia ja avioliittoa julkisivun takana, jolloin kävi selvästi ilmi kirjailijan kahtiajakautunut elämä. Montgomery sai presbyteerisen ja viktoriaanisen kasvatuksen ja oppi jo lapsena huomioimaan sen, mitä muut ihmiset ajattelevat hänestä. Hän eli pienissä maaseutuyhteisöissä, joissa juoruilu oli yksi kontrollin väline. Papin vaimolla oli velvollisuuksia seurakunnassa ja pappilan hoidossa, ja Montgomery hoiti ne tarmokkaasti ja velvollisuudentuntoisesti. Hänellä oli apulainen pappilassa, jossa arki sujui viikkoaikataulun mukaisesti. Papin vaimon roolin lisäksi Montgomery jatkoi omaa kirjoittamistyötään ja hänen runsaat tulonsa mahdollistivat nelihenkisen perheen monet hankinnat. Hänen avioliittonsa oli vaikea, sillä aviomies kärsi uskonnollisesta melankoliasta ja asia piti salata seurakuntalaisilta. Montgomery käsittelee uskonnollisia teemoja romaaneissaan ja päiväkirjassaan. Hänen uskonnolliset ajatuksensa erosivat presbyteerikirkon opista useassa kohdin. Hän ei uskonut moneenkaan opinkappaleeseen, kohtasi Jumalan ennemmin luonnossa ollessaan yksin kuin kirkossa seurakunnan keskellä sekä ajatteli kristinuskon olevan jäännös menneestä ja tieteen ottaneen sen paikan Jumalan toiminnan kanavana. Kirjailijan ajattelussa on yhtymäkohtia transsendentalismiin, teosofiaan ja darwinismiin. Hän oli innokas psykologisen kirjallisuuden lukija ja sovelsi oppejaan käytäntöön. Hän uskoi unien välittävän viestejä. Kirkkokunta oli hänelle kuitenkin merkittävä identiteetin rakentaja. Papin vaimon roolin ja yksityisesti kriittisen ajattelijan roolin yhteensovittaminen aiheutti Montogmerylle ongelmia ja väsymystä. Hän kätki uskonnolliset ajatuksensa ja yksinäisyyden aiheuttaman kivun päiväkirjaansa, jonka hän toivoi julkaistavan viimeistään kuolemansa jälkeen. Kaikenlainen kirjoittaminen oli hänelle pakoa todellisuudesta ja auttoi häntä jaksamaan. Otsikon sitatti kuvaa Montgomeryn suhdetta kristinuskoon: hän käytti kristillisiä ilmauksia, mutta muokkasi niiden sisältöä omaa uskoaan vastaavaksi. Taivas ja helvetti kuvasivat usein hänen henkistä olotilaansa sanojen uskonnollisen merkityksen sijasta.

Sairaanhoitajat työn imussa? Palkkatyön sisällön ja kulttuuristen lähtökohtien tasapainossa

Tutkimuksen tavoitteena on selvittää, mikä saa pitkän työuran tehneet sairaanhoitajat innostumaan työstään. Taustalla on yhteiskunnallinen tilanne, jossa työelämän vetovoimaisuuden lisääminen ja ikääntyvien työntekijöiden työssä jaksaminen ovat keskeisiä poliittisia tavoitteita. Aihetta lähestytään positiivisesta psykologiasta lähtöisin olevan työn imun käsitteen avulla. Se on määritelty pysyväksi, ”myönteiseksi, tunne- ja motivaatiotäyttymyksen tilaksi, jota luonnehtivat tarmokkuus, omistautuminen ja uppoutuminen työhön” (Hakanen 2009a, 9). Tutkimuksessa kysytään, voidaanko työn imua ymmärtää myös sosiologisesta näkökulmasta. Oletuksena on, että käsitteen taustalla on muutakin kuin psykologisesta perinteestä käsin jäsentyvää vaihtelua. Empiirisen aineiston muodostavan 11 sairaanhoitajan koko työuraa ja nykyistä työtä koskevat tiettyihin teemoihin ankkuroidut syvähaastattelut. Otosta poimittaessa on etsitty sellaisia haastateltavia, jotka kokevat kantavansa työn imua. Aineiston analyysitapana on käytetty matriisin avulla sovellettua kvalitatiivista sisällönanalyysiä. Työn imua hahmotetaan analyysissä henkilöhistoriallisten haastatteluiden – menneen, nykyisen ja tulevan – kautta. Pyrkimyksenä on etsiä tarinoita mahdollisesti yhdistävää kulttuurista muotoa ja ymmärtää, mihin se perustuu. Analyysin nojalla vastuurationaalisuuden käsite (esim. Korvajärvi 1986) näyttäisi jäsentävän osan haastateltavien suhteesta työhönsä. Avain työn imun löytymiseen näissä tarinoissa on kuitenkin se, kuinka haastateltavilla on ollut henkilökohtainen halu mennä eteenpäin ja kykyä ratkaista ongelmia työuransa aikana ja nykyisessä työssään. Tämä havainto tulkitaan Max Weberin (1922; 1980) käsitteiden – arvorationaalisen ja päämäärärationaalisen toiminnan väliseen suhteen – avulla. Tulokseksi syntyy oletus siitä, että analyysin kohteena olevissa tarinoissa on kyse yhteisestä kulttuurisesta tarinasta siitä, millainen on hyvä ihminen, miten hyvä ihminen toteuttaa itseään työssä ja miten hän tekee työtään: tarmokkaasti, omistautuen ja uppoutuen. Henkilökohtainen halu mennä eteenpäin ja kyky ratkaista ongelmia nojaa sairaanhoitajien erityiseen eetokseen, kutsumustyöhön ja hoivan moraaliin tavalla, joka on rakenteellisesti yhtäläinen protestanttisuutta leimaavan yksilöllisen jumalasuhteen kanssa. Lisäksi analyysin perusteella esitetään, että työn imun edellytys on arvorationaalisen eetoksen lisäksi oikeanlainen, riittävät työn voimavarat sisältävä ympäristö, jossa hoitotyön keskeiset palkinnot on mahdollista saavuttaa. Tällöin palkkatyön sisältö kohtaa kulttuuriset lähtökohdat, ja tulos näkyy työn imuna. Keskeisimmät taustoittavat lähteet ovat Henriksson, Lea & Wrede, Sirpa (toim.) (2004a). Hyvinvointityön ammatit ja Hakanen, Jari (2009a). Työn imun arviointimenetelmä (Utrecht Work Engagement Scale). Sosiologisen tulkinnan kannalta tärkein teoreettinen lähde on Weber, Max (1980): Protestanttinen etiikka ja kapitalismin henki.

Breakage of a drop of inviscid fluid due to a pressure fluctuation at its surface

In this work, an attempt is made to gain a better understanding of the breakage of low-viscosity drops in turbulent flows by determining the dynamics of deformation of an inviscid drop in response to a pressure variation acting on the drop surface. Known scaling relationships between wavenumbers and frequencies, and between pressure fluctuations and velocity fluctuations in the inertial subrange are used in characterizing the pressure fluctuation. The existence of a maximum stable drop diameter d(max) follows once scaling laws of turbulent flow are used to correlate the magnitude of the disruptive forces with the duration for which they act. Two undetermined dimensionless quantities, both of order unity, appear in the equations of continuity, motion, and the boundary conditions in terms of pressure fluctuations applied on the surface. One is a constant of proportionality relating root-mean-square values of pressure and velocity differences between two points separated by a distance l. The other is a Weber number based on turbulent stresses acting on the drop and the resisting stresses in the drop due to interfacial tension. The former is set equal to 1, and the latter is determined by studying the interaction of a drop of diameter equal to d(max) with a pressure fluctuation of length scale equal to the drop diameter. The model is then used to study the breakage of drops of diameter greater than d(max) and those with densities different from that of the suspending fluid. It is found that, at least during breakage of a drop of diameter greater than d(max) by interaction with a fluctuation of equal length scale, a satellite drop is always formed between two larger drops. When very large drops are broken by smaller-length-scale fluctuations, highly deformed shapes are produced suggesting the possibility of further fragmentation due to instabilities. The model predicts that as the dispersed-phase density increases, d(max) decreases.

Carbon-13 and proton relaxation study of backbone dynamics of poly(vinyl acetate) in solution

The dynamics of poly(vinyl acetate) in toluene solution has been examined by C-13 and proton relaxation. C-13 spin-lattice relaxation time and nuclear Overhauser enhancement measurements were carried out as a function of temperature at 50.3 and 100.6 MHz. The spin-lattice relaxation times for backbone protons were measured at different temperatures at 200 MHz. The relaxation data have been analyzed using the Hall-Weber-Helfand (HWH) model, which describes backbone dynamics in terms of conformational transitions and the Dejean-Laupretre-Monnerie (DLM) model, which includes bond librations in addition to conformational transitions. The parameters obtained from the analysis of C-13 relaxation data were utilized to predict the proton relaxation data. The DLM model was found to be more successful in reproducing the experimental results. To study the influence of libration further, proton relaxation data for poly(vinyl acetate) over a wider range of temperature reported in the literature were analyzed by these two models. The DLM model could reproduce the experimental data at all temperatures whereas the HWH model was found to be successful only in accounting for the experimental data at high temperatures. The results demonstrate the importance of including the librational mode in the description of the backbone dynamics in polymers.