5,274 research outputs found

    Microplastics in Arctic marine ecosystems:sea ice and sediments

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    Mikromuovit arktisissa meriekosysteemeissä : sedimentti ja jää. Tiivistelmä. Mikromuovit ovat alle viiden millimetrin pituisia muovikappaleita, ja niitä löytyy tällä hetkellä kaikkialta maapallolta. Arktiset meriekosysteemit ovat erityisen herkkiä alueita, ja niiden mikromuoveista tiedetään vielä hyvin vähän. Tässä työssä tarkastelen arktisen alueen muovia sedimenteistä ja jäästä, sekä kuinka ne vaikuttavat eliöihin näissä systeemeissä

    Estimates of the duration of untreated acute malnutrition in children from Niger.

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    Expected incidence of acute malnutrition is the most appropriate measure for projecting the needs of a nutritional treatment program over time in terms of staffing, food, and other treatments, but direct estimation of incidence is rarely feasible at the onset of an intervention. While incidence may be approximated as prevalence/average duration, ethical constraints preclude measurement of the duration of acute malnutrition in the absence of treatment. The authors used a compartmental model to estimate the duration of untreated moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) in children aged 6-60 months. The model was informed by data from a community-based cohort of children in Niger followed from August 2006 to March 2007. Maximum likelihood estimates for the duration of untreated MAM, defined by weight-for-height z score and middle upper arm circumference, were 75-81 days and 101-116 days, respectively. The duration of untreated SAM, defined by weight-for-height z score, was 45 days. The duration of untreated MAM appears to have been shorter among children aged 6-35 months compared with those aged 36-60 months. Such estimates of the duration, and thus incidence, of untreated malnutrition can be used to improve projections of program needs and estimates of the global burden of acute malnutrition

    A review of clinical trials in dietary interventions to decrease the incidence of coronary artery disease

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    Of the associations between dietary elements and coronary artery disease (CAD), the greatest body of evidence deals with the beneficial effect of reducing the dietary intake of saturated fatty acids and cholesterol. Furthermore, it is well established, on the basis of convincing evidence, that reduction in serum total cholesterol results in reduction in coronary morbidity and mortality, as well as in regression of other atherosclerotic manifestations.In fact, dietary intervention studies revealed that it is possible to reduce the incidence of coronary death and nonfatal myocardial infarction, as well as manifestations of atherosclerosis in cerebral and peripheral arteries, by reducing dietary intake of saturated fat and cholesterol. In two recently reported dietary interventions the incidence of coronary events, especially coronary mortality, and total mortality were reduced by increased intake of n-3 long-chain polyunsaturated fatty acids and by a modification of the diet toward a Mediterranean-type diet (rich in α-linolenic acid. In addition to those findings, the potential efficacy of the dietary newcomers phytostanol and phytosterol esters on reducing coronary incidence is discussed in the present review

    On the number of signals in multivariate time series

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    We assume a second-order source separation model where the observed multivariate time series is a linear mixture of latent, temporally uncorrelated time series with some components pure white noise. To avoid the modelling of noise, we extract the non-noise latent components using some standard method, allowing the modelling of the extracted univariate time series individually. An important question is the determination of which of the latent components are of interest in modelling and which can be considered as noise. Bootstrap-based methods have recently been used in determining the latent dimension in various methods of unsupervised and supervised dimension reduction and we propose a set of similar estimation strategies for second-order stationary time series. Simulation studies and a sound wave example are used to show the method's effectiveness

    Local search based evolutionary multi-objective optimization algorithm for constrained and unconstrained problems

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    Evolutionary multi-objective optimization algorithms are commonly used to obtain a set of non-dominated solutions for over a decade. Recently, a lot of emphasis have been laid on hybridizing evolutionary algorithms with MCDM and mathematical programming algorithms to yield a computationally efficient and convergent procedure. In this paper, we test an augmented local search based EMO procedure rigorously on a test suite of constrained and unconstrained multi-objective optimization problems. The success of our approach on most of the test problems not only provides confidence but also stresses the importance of hybrid evolutionary algorithms in solving multi-objective optimization problems

    Carbon dynamics in a Boreal land-stream-lake continuum during the spring freshet of two hydrologically contrasting years

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    We studied in 2013 and 2014 the spring carbon dynamics in a Boreal landscape consisting of a lake and 15 inflowing streams and an outlet. The first year had weather and a hydrological regime typical of past years with a distinct spring freshet connected with the thaw of the average snowpack. The latter year had higher air temperatures which did not permit snow accumulation, despite similar winter precipitation. As such, there was hardly any spring freshet in 2014, and stream discharge peaked in January, i.e., the conditions resembled those predicted in the future climate. Despite the hydrological differences between the years, there were only small interannual differences in the stream CO2 and DOC concentrations. The relationship between the concentrations and discharge was stronger in the typical year. CO2 concentrations in medium-sized streams correlated negatively with the discharge, indicating dilution effect of melting snowpacks, while in large-sized streams the correlation was positive, suggesting stronger groundwater influence. The DOC pathway to these streams was through the subsurface soil layers, not the groundwater. The total amount of carbon transported into the lake was ca. 1.5-fold higher in the typical year than in the year with warm winter. In 2013, most of the lateral inputs took place during spring freshet. In 2014, the majority of inputs occurred earlier, during the winter months. The lateral CO2 signal was visible in the lake at 1.5 m depth. DOC dominated the carbon transport, and in both years, 12% of the input C was in inorganic form.Peer reviewe

    Hard Diffraction From Quasi-Elastic Dipole Scattering

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    The contribution to diffraction dissociation of virtual photons due to quasi-elastic scattering of the qq-qˉ\bar q component is calculated in the framework of the QCD dipole picture. Both longitudinal and transverse components of the cross-section are given. It is shown that, at fixed mass of the diffractively produced system, quantum mechanical interference plays an important r\^ ole. Phenomenological consequences are discussed.Comment: latex + now: 4 encapsulated poscript figure

    Effects of gadolinium and tin to the production of oxidative enzymes and the growth of five basidiomycetous fungi

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    Effects of gadolinium (Gd) and tin (Sn) on the growth and production of oxidative enzymes with five basidiomycetous fungi were tested. For this study we have selected well-known white-rot fungi Obba rivulosa and Kuehneromyces mutabilis, in addition to this we have tested three new isolates, the white-rot fungus Phlebia subochracea, the litter-degrading fungus Gymnopus dryophilus and the brown-rot fungus Heliocybe sulcata. This approach allowed us to find possible new sources for oxidative enzymes, such as laccases and versatile peroxidases (VPs). All five tested fungi grew in the presence of Gd (0-200 mg/l) or Sn (0-200 mg/l) on ABTS (2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) containing plates. The growth rate of H. sulcata was tolerant to Gd and Sn (0- 200 mg/l). The growth rates of P. subochracea and G. dryophilus were sensitive to Gd (5-200 mg/l) and Sn (5-200 mg/l). O. rivulosa, K. mutabilis, P. subochracea and G. dryophilus formed colour zones on the ABTS plates indicating that these fungi produced oxidative enzymes, most probably laccases. The brown-rot fungus H. sulcata did not form colour zone on the ABTS plate indicating that this fungus did not produce laccase. The production of laccase with G. dryophilus and K. mutabilis was tolerant to Gd (0-200 mg/l) and Sn (0-200 mg/l). The production of laccase with P. subochracea was sensitive to Gd (5-200 mg/l) and Sn (5-200 mg/l). P. subochracea decolorized the dye Reactive Black 5 without or with Gd and Sn (0- 200 mg/l) indicating the production of VP. O. rivulosa, K. mutabilis, G. dryophilus and H. sulcata did not produce VP. The production of VP by P. subochracea was sensitive to 200 mg/l Gd and Sn.Peer reviewe
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