943 resultados para residence restrictions
Resumo:
Work has a central role in the lives of big share of adult Finns and meals they eat during the workday comprise an important factor in their nutrition, health, and well-being. On workdays, lunch is mainly eaten at worksite canteens or, especially among women, as a packed meal in the workplace s break room. No national-level data is available on the nutritional quality of the meals served by canteens, although the Finnish Institute of Occupational Health laid out the first nutrition recommendations for worksite canteens in 1971. The aim of this study was to examine the contribution of various socio-demographic, socioeconomic, and work-related factors to the lunch eating patterns of Finnish employees during the working day and how lunch eating patterns influence dietary intake. Four different population-based cross-sectional datasets were used in this thesis. Three of the datasets were collected by the National Institute for Health and Welfare (Health Behaviour and Health among the Finnish Adult Population survey from 1979 to 2001, n=24746, and 2005 to 2007, n=5585, the National Findiet 2002 Study, n=261), and one of them by the Finnish Institute of Occupational Health (Work and Health in Finland survey from 1997, 2000, and 2003, n=6369). The Health Behaviour and Health among the Finnish Adult Population survey and the Work and Health in Finland survey are nationally representative studies that are conducted repeatedly. Survey information was collected by self-administered questionnaires, dietary recalls, and telephone interviews. The frequency of worksite canteen use has been quite stable for over two decades in Finland. A small decreasing trend can be seen in all socioeconomic groups. During the whole period studied, those with more years of education ate at worksite canteens more often than the others. The size of the workplace was the most important work-related determinant associated with the use of a worksite canteen. At small workplaces, other work-related determinants, like occupation, physical strain at work, and job control, were also associated with canteen use, whereas at bigger workplaces the associations were almost nonexistent. The major social determinants of worksite canteen availability were the education and occupational status of employees and the only work-related determinant was the size of the workplace. A worksite canteen was more commonly available to employees at larger workplaces and to those with the higher education and the higher occupational status. Even when the canteen was equally available to all employees, its use was nevertheless determined by occupational class and the place of residence, especially among female employees. Those with higher occupational status and those living in the Helsinki capital area ate in canteens more frequently than the others. Employees who ate at a worksite canteen consumed more vegetables and vegetable and fish dishes at lunch than did those who ate packed lunches. Also, the daily consumption of vegetables and the proportion of the daily users of vegetables were higher among those male employees who ate at a canteen. In conclusion, life possibilities, i.e. the availability of a canteen, education, occupational status, and work-related factors, played an important role in the choice of where to eat lunch among Finnish employees. The most basic prerequisite for eating in a canteen was availability, but there were also a number of underlying social determinants. Occupational status and the place of residence were the major structural factors behind individuals choices in their lunch eating patterns. To ensure the nutrition, health, and well-being of employees, employers should provide them with the option to have good quality meals during working hours. The availability of worksite canteens should be especially supported in lower socioeconomic groups. In addition, employees should be encouraged to have lunch at a worksite canteen when one is available by removing structural barriers to its use.
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If the solar dynamo operates in a thin layer of 10,000-km thickness at the interface between the convection zone and the radiative core, using the facts that the dynamo should have a period of 22 years and a half-wavelength of 40 deg in the theta-direction, it is possible to impose restrictions on the values which various dynamo parameters are allowed to have. It is pointed out that the dynamo should be of alpha-sq omega nature, and kinematical calculations are presented for free dynamo waves and for dynamos in thin rectangular slabs with appropriate boundary conditions. An alpha-sq omega dynamo is expected to produce a significant poloidal field which does not leak to the solar surface. It is found that the turbulent diffusity eta and alpha-coefficient are restricted to values within about a factor of 10, the median values being eta of about 10 to the 10th sq cm/sec and alpha of about 10 cm/sec. On the basis of mixing length theory, it is pointed out that such values imply a reasonable turbulent velocity of the order 30 m/s, but rather small turbulent length scales like 300 km.
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The nuclear Overhauser effect equations are solved analytically for a homonuclear group of spins whose sites are periodically arranged, including the special cases where the spins lie at the vertices of a regular polygon and on a one-dimensional lattice. t is shown that, for long correlation times, the equations governing magnetization transfer resemble a diffusion equation. Furthermore the deviation from exact diffusion is quantitatively related to the molecular tumbling correlation time. Equations are derived for the range of magnetization travel subsequent to the perturbation of a single spin in a lattice for both the case of strictly dipolar relaxation and the more general situation where additional T1 mechanisms may be active. The theory given places no restrictions on the delay (or mixing) times, and it includes all the spins in the system. Simulations are presented to confirm the theory.
Resumo:
To test the reliability of the radiocarbon method for determining root age, we analyzed fine roots (originating from the years 1985 to 1993) from ingrowth cores with known maximum root age (1 to 6 years old). For this purpose, three Scots pine (Pinus sylvestris L.) stands were selected from boreal forests in Finland. We analyzed root 14C age by the radiocarbon method and compared it with the above-mentioned known maximum fine root age. In general, ages determined by the two methods (root 14C age and ingrowth core root maximum age) were in agreement with each other for roots of small diameter (<0.5mm). By contrast, in most of the samples of fine roots of larger diameter (1.5-2mm), the 14C age of root samples of 1987-89 exceeded the ingrowth core root maximum age by 1-10 years. This shows that these roots had received a large amount of older stored carbon from unknown sources in addition to atmospheric CO2 directly from photosynthesis. We conclude that the 14C signature of fine roots, especially those of larger diameter, may not always be indicative of root age, and that further studies are needed concerning the extent of possible root uptake of older carbon and its residence time in roots. Keywords: fine root age, Pinus sylvestris, radiocarbon, root carbon, ingrowth cores, tree ring
Resumo:
Tutkielman tarkoituksena on rakentaa malli, jolla voidaan arvioida maitotilan toimintaa monipuolisesti ravinnehuuhtouman kannalta. Tavoitteena on ennen muuta analyyttinen tarkastelu siten, että kuitenkin huomioiden maidontuotannon ominaispiirteet, keskeisinä esimerkkeinä ravinnon, maidontuotannon ja lannan ominaisuuksien väliset riippuvuudet. Analyysissa tarkastellaan tilanomistajan yksityisen hyödynmaksimoinnin ja yhteiskunnan tavoitteiden eroavaisuutta. Lisäksi johdetaan optimaaliset ohjauskeinot ja arvioidaan eräiden yksinkertaisten ohjauskeinojen vaikuttavuutta. Mallin analysoinnin perusteella yksityinen ja yhteiskunnallinen optimiratkaisu eroavat toisistaan kaikkien päätösmuuttujien osalta. Ei voida kuitenkaan yleispätevästi sanoa muutosten merkittävyyttä tai suuntaa ottamatta kantaa mallin funktiomuotoihin ja parametriarvoihin. Optimaaliset ohjauskeinot tulisi asettaa keinolannoitteen ja lannan levitykselle, väkirehuruokinnalle ja säilörehun viljelylle, mutta ei eläinten määrälle. Toisaalta optimaaliset ohjauskeinot ovat hyvin monimutkaisia. Tarkasteltujen yksinkertaisempien ohjauskeinojen vaikuttavuutta ei voida tarkasti arvioida analyyttisella tasolla. Numeeristen tulosten perusteella yhteiskunnallisessa optimissa eläinmäärä olisi hieman yksityistä optimia pienempi, väkirehun käyttö vähäisempää, enemmän peltoa allokoitaisiin säilörehun viljelyyn ja lannoitustasot olisivat kautta linjan hieman pienemmät. Lannanlevitykset eroavat etäisyyden suhteen: molemmissa tapauksissa lannanlevityksen intensiteetti kasvaa kohti tilan keskusta kuljettaessa, mutta yksityisessä optimissa lähimmälle pellolle dumpataan kaikki ylimääräinen lanta, kun taas yhteiskunnallisessa optimissa lanta levitetään tasaisemmin eri pelloille. Ero kokonaishyvinvoinnissa jää pieneksi, mutta eläinmäärän kasvu kärjistäisi lannan dumppauksen aiheuttamia huuhtoumahaittoja. Yksinkertaisista ohjauskeinoista lannoitusrajoitus sekä ravinne- ja keinolannoitevero osoittautuivat kohtalaisen käyttökelpoisiksi numeeristen tulosten perusteella. Sen sijaan eläinmäärän rajoittaminen ja lannan kuljetuskustannuksia kompensoivat tuet vaikuttavat tulosten perusteella huonoilta ratkaisuilta.
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This thesis explores the link between South-South remittance and development. It attempts to establish improved understanding about the role of immigrants as agents of constituency growth and development. By doing so, it illuminates the dark corners of the policy implications that the unconventional development agency of immigrants might have for countries in the Organization ft Economic Cooperation and Development (OECD). The thesis problematises the existence of state-centric international cooperation as providing the recipe for failed Aid in the face of global poverty menace. In the last half a century, the relative shi' of focus to non-state actors brought about the proliferation of NGOs. That, intrun, helped improve international access to crisis situations; however, their long-term remedial impacts on poverty and development have been contested. Major misgivings for non-governmental organizations (NGOs) are, on one hand, low level goal-bound expenditures and lack of independence from influence of the state, on the other. Therefore, the thesis enterprises to empirically verify its fundamental question whether remitting immigrants constitute an alternative development agency to the traditional players: the State and NGOs. Its main arguments are: due to state's failures in bringing sustainable development in many countries of the South, the future of poverty reduction and development also rests in immigrants' remittances. Nonetheless, in the last decade, remittance security-nexus dominated its discourse. Because of that remittance was viewed as something requiring global regime and restrictions. These temptations to tightly regulate remittance flows carry the danger of overlooking its trans-boundary nature and its strong link with livelihood of the poor. Therefore, to avoid unintended consequences of interventions, there need to be clear policy that bases itself on a discursive knowledge on the issues of North-South and South-South remittances The study involved both literature based and empirical research. It employed Discourse Analysis (C as main method for the former and snow-balling as its approach for the latter. For the first part the thesis constructed three conceptual models, these are: metrological model, police model and ecological model on remittance development-nexus. Through this modeling, the thesis achieved better deconstruction on the concepts remittance, immigrants and development agency. The protagonists of each model, the values and interests they represent, and their main arguments along various lines of dichotomies have been discussed. For instance, the main treats of meteorological model include: it sees remittance as transitional economic variable which require constant speculations and global management; it acts as meteorological station for following up or predicting the level, direction, flow and movement of global remittance. It focuses on official lines and considers the state as legitimate recipient of advic and positive consequence of remittance. On the other hand, police model views remittance as beir at best, development neutral or as an illicit activity requiring global regulations and tight control. Both immigrants and remittance viewed as subversive to establishments. It gives primacy to state stable agent of development and a partner for international cooperation. The anti-thesis to the police model is supplied by ecological model, which this thesis is a part. Ecological model on remittance and immigrants argues that, tight global regulations alone cannot be a panacea for possible abuse of informal remittance system. Ecological model, not only links remittance to poverty reduction, the main trust of development, but also considers the development agency of immigrants as critical factor for 21st century north-south development intervention. It sees immigrants as development conscious and their remittance instrument as most stable flow of finance to the developing countries. Besides, it sees remittance as effective poverty solutions than Foreign Direct Investment and international AID. This thesis focuses on the significance of South-South remittance and investigates the South Africa - Ethiopia remittance corridor, as case study; and empirically verifies the role of Ethiopian (Kembata and Hadiya) immigrants in South Africa as agents of local development back home. The study involved techniques of interview, group discussions, observations and investigative study. It also looked into the determinants of their migration to South Africa, and their remittance to Ethiopia. The theoretical models in the first part of the thesis have been operationalised throughout the empirical part to verify if the Kembata and Hadiya immigrants played the crucial role in their household poverty and local development in comparison with the Ethiopian state and the NGOs involved in the system. As evidenced by the research the thesis has made three distinct contributions to the discourse of remittance development-nexus. Fist, it systematized the debate about linkages between remittance, immigrants, development agency and policy of international cooperation by creating three conceptual models (school of thoughts); second, it singled out remitting immigrants as new agents of development in the South; third, it deconstructed concept of remittance and established South¬South remittance as additional sphere of academic investigation. In addition to the above contributions, the thesis finds that Kembata and Hadiya immigrants have engaged in various developmental activities in their locality than usually anticipated. Hence, it concludes that Ethiopian immigrants constitute an alternative development agency to the state and other non-state actors in their country, and the lesson can be applied to poverty reduction strategies in most developing countries.
Resumo:
Estuaries have been suggested to have an important role in reducing the nitrogen load transported to the sea. We measured denitrification rates in six estuaries of the northern Baltic Sea. Four of them were river mouths in the Bothnian Bay (northern Gulf of Bothnia), and two were estuary bays, one in the Archipelago Sea (southern Gulf of Bothnia) and the other in the Gulf of Finland. Denitrification rates in the four river mouths varied between 330 and 905 mu mol N m(-2) d(-1). The estuary bays at the Archipelago Sea and the Gulf of Bothnia had denitrification rates from 90 mu mol N m(-2) d(-1) to 910 mu mol N m(-2) d(-1) and from 230 mu mol N m(-2) d(-1) to 320 mu mol N m(-2) d(-1), respectively. Denitrification removed 3.6-9.0% of the total nitrogen loading in the river mouths and in the estuary bay in the Gulf of Finland, where the residence times were short. In the estuary bay with a long residence time, in the Archipelago Sea, up to 4.5% of nitrate loading and 19% of nitrogen loading were removed before entering the sea. According to our results, the sediments of the fast-flowing rivers and them estuary areas with short residence times have a limited capacity to reduce the nitrogen load to the Baltic Sea.
Resumo:
Maurice Merleau-Ponty (1908-1961) has been known as the philosopher of painting. His interest in the theory of perception intertwined with the questions concerning the artist s perception, the experience of an artwork and the possible interpretations of the artwork. For him, aesthetics was not a sub-field of philosophy, and art was not simply a subject matter for the aesthetic experience, but a form of thinking. This study proposes an opening for a dialogue between Merleau-Pontian phenomenology and contemporary art. The thesis examines his phenomenology through certain works of contemporary art and presents readings of these artworks through his phenomenology. The thesis both shows the potentiality of a method, but also engages in the critical task of finding the possible limitations of his approach. The first part lays out the methodological and conceptual points of departure of Merleau-Ponty s phenomenological approach to perception as well as the features that determined his discussion on encountering art. Merleau-Ponty referred to the experience of perceiving art using the notion of seeing with (voir selon). He stressed a correlative reciprocity described in Eye and Mind (1961) as the switching of the roles of the visible and the painter. The choice of artworks is motivated by certain restrictions in the phenomenological readings of visual arts. The examined works include paintings by Tiina Mielonen, a photographic work by Christian Mayer, a film by Douglas Gordon and Philippe Parreno, and an installation by Monika Sosnowska. These works resonate with, and challenge, his phenomenological approach. The chapters with case studies take up different themes that are central to Merleau-Ponty s phenomenology: space, movement, time, and touch. All of the themes are interlinked with the examined artworks. There are also topics that reappear in the thesis, such as the notion of écart and the question of encountering the other. As Merleau-Ponty argued, the sphere of art has a particular capability to address our being in the world. The thesis presents an interpretation that emphasises the notion of écart, which refers to an experience of divergence or dispossession. The sudden dissociation, surprise or rupture that is needed in order for a meeting between the spectator and the artwork, or between two persons, to be possible. Further, the thesis suggests that through artworks it is possible to take into consideration the écart, the divergence, that defines our subjectivity.
Resumo:
Various geometrical and energetic distribution functions and other properties connected with the cage-to-cage diffusion of xenon in sodium Y zeolite have been obtained from long molecular dynamics calculations. Analysis of diffusion pathways reveals two interesting mechanisms-surface-mediated and centralized modes for cage-to-cage diffusion. The surface-mediated mode of diffusion exhibits a small positive barrier, while the centralized diffusion exhibits a negative barrier for the sorbate to diffuse across the 12-ring window. In both modes, however, the sorbate has to be activated from the adsorption site to enable it to gain mobility. The centralized diffusion additionally requires the sorbate to be free of the influence of the surface of the cage as well. The overall rate for cage-to-cage diffusion shows an Arrhenius temperature dependence with E(a) = 3 kJ/mol. It is found that the decay in the dynamical correction factor occurs on a time scale comparable to the cage residence time. The distributions of barrier heights have been calculated. Functions reflecting the distribution of the sorbate-zeolite interaction at the window and the variations of the distance between the sorbate and the centers of the parent and daughter cages are presented.
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Two dhole (Cuon alpinus) packs were monitored in Mudumalai Sanctuary, southern India, during 1989-93 to look at population dynamics, movement pattern, and foraging strategy and their inter-relationship with the maintenance of social groups. Pack size fluctuated substantially (4-18 and 4-25 in the two packs) owing to dispersal and demographic factors such as females not breeding in a given year. Both packs killed a much higher proportion of chital (Axis axis) and sambar (Cervus unicolor) fawns (< one year old) than their availability in the population. There was no correlation between pack size and body weight of prey killed, while per capita consumption of meat declined with increasing pack size. Home-range area (83.3 km(2) and 54.2 km(2) for the two packs) was not correlated with pack size. Pack movement from one resource patch (consisting of resting sites and aggregations of prey species) to another was not random or based on factors such as inter-patch distance or relative prey densities. There was no difference in mean residence time of the pack across the four resource patches; the pack moved across these in a sequential manner in one direction. We conclude that dholes live in groups not because of any advantages accruing from enhanced group sizes through increased per capita yield of food, but as a consequence of the dispersion of resources.
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A mechanism is presented here for the amplification of large-scale nonaxisymmetric magnetic fields as a manifestation of the dynamo effect. We generalize a result on restrictions of dynamo actions due to laminar flow originally derived by Zeldovich, Ruzmaikin, and Sokolov [Magnetic Fields in Astrophysics (Gordon and Breach, New York, 1983)]. We show how a screwlike motion having phi and z components of velocity can help to grow a magnetic field. This model postulates a large-scale flow having phi and z components with radial dependences (helical flow). Shear in the radial field, because of a near-flux-freezing condition, causes amplification of the phi component of the magnetic field. The radial and axial components grow due to the presence of turbulent diffusion. The shear in the large scale flow induces an indefinite growth of magnetic field without the a effect; nevertheless, turbulent diffusion forms an important part in the overall mechanism.
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Sufficiently long molecular dynamics simulations have been carried out on spherical monatomic sorbates in NaY zeolite, interacting via simple Lennard-Jones potentials, to investigate the dependence of the levitation effect on the temperature. Simulations carried out in the range 100-300 K suggest that the anomalous peak in the diffusion coefficient (observed when the levitation parameter, gamma, is near unity) decreases in intensity with increase in temperature. The rate of cage-to-cage migrations also exhibits a similar trend. The activation energy obtained from Arrhenius plots is found to exhibit a minimum when the diffusion coefficient is a maximum, corresponding to the gamma approximate to 1 sorbate diameter. In the linear or normal regime, the activation energy increases with increase in sorbate diameter until it shows a sharp decrease in the anomalous regime. Locations and energies of the adsorption sites and their dependence on the sorbate size gives interesting insight into the nature of the underlying potential-energy surface and further explain the observed trend in the activation energy with sorbate size. Cage residence times, tau(c), show little or no change with temperature for the sorbate with diameter corresponding to gamma approximate to 1, whereas there is a significant decrease in tau(c) with increase in temperature for sorbates in the linear regime. The implications of the present study for the separation of mixtures of sorbates are discussed.
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The unique features of a macromolecule and water as a solvent make the issue of solvation unconventional, with questions about the static versus dynamic nature of hydration and the, physics of orientational and translational diffusion at the boundary. For proteins, the hydration shell that covers the surface is critical to the stability of its structure and function. Dynamically speaking, the residence time of water at the surface is a signature of its mobility and binding. With femtosecond time resolution it is possible to unravel the shortest residence times which are key for the description of the hydration layer, static or dynamic. In this article we review these issues guided by experimental studies, from this laboratory, of polar hydration dynamics at the surfaces of two proteins (Subtilisin Carlsberg (SC) and Monellin). The natural probe tryptophan amino acid was used for the interrogation of the dynamics, and for direct comparison we also studied the behavior in bulk water - a complete hydration in 1 ps. We develop a theoretical description of solvation and relate the theory to the experimental observations. In this - theoretical approach, we consider the dynamical equilibrium in the hydration shell, defining the rate processes for breaking and making the transient hydrogen bonds, and the effective friction in the layer which is defined by the translational and orientational motions of water molecules. The relationship between the residence time of water molecules and the observed slow component in solvation dynamics is a direct one. For the two proteins studied, we observed a "bimodal decay" for the hydration correlation function, with two primary relaxation times: ultrafast, typically 1 ps or less, and longer, typically 15-40 ps, and both are related to the residence time at the protein surface, depending on the binding energies. We end by making extensions to studies of the denatured state of the protein, random coils, and the biomimetic micelles, and conclude with our thoughts on the relevance of the dynamics of native structures to their functions.
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Road transportation, as an important requirement of modern society, is presently hindered by restrictions in emission legislations as well as the availability of petroleum fuels, and as a consequence, the fuel cost. For nearly 270 years, we burned our fossil cache and have come to within a generation of exhausting the liquid part of it. Besides, to reduce the greenhouse gases, and to obey the environmental laws of most countries, it would be necessary to replace a significant number of the petroleum-fueled internal-combustion-engine vehicles (ICEVs) with electric cars in the near future. In this article, we briefly describe the merits and demerits of various proposed electrochemical systems for electric cars, namely the storage batteries, fuel cells and electrochemical supercapacitors, and determine the power and energy requirements of a modern car. We conclude that a viable electric car could be operated with a 50 kW polymer-electrolyte fuel cell stack to provide power for cruising and climbing, coupled in parallel with a 30 kW supercapacitor and/or battery bank to deliver additional short-term burst-power during acceleration.
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A pseudo-spectral method based on Fourier expansions in a Cartesian coordinate system is shown to be an economical method for direct numerical simulation studies of transitional round jets, Several characteristics of the solutions are presented to establish the validity of the solutions in spite of the unnatural choices. We show that neither periodicity, nor the use of a Cartesian system have adversely affected the simulations, Instead, there are benefits in terms of ease of computing and lack of the usual restrictions due to grid structure near the jet axis. By computing the simultaneous evolution of passive scalers, the process of reaction in round jet burners, between a fuel-laden jet and an ambient oxidizer, was also simulated. Some typical solutions are shown and then the results of analysis of these data are summarized. (C) 2001 Elsevier Science Ltd, All rights reserved.