71 research outputs found

    Ecophysiology and dynamics of nitrogen removal bacteria in a sequencing batch reactor during wastewater treatment start‑up

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    Nitrogen removal communities performing wastewater treatment consist of ammonia oxidisers, nitrite oxidisers, denitrifiers, and anammox bacteria, and the proportion and activity of particular microbial groups depend not only on the physiochemical parameters of the bioreactor, but also on the composition of the inoculum. Nitrifiers and denitrifiers usually dominate in conventional wastewater treatment systems due to the fact that nitrification and denitrification are the most commonly used nitrogen removal processes. However, from the economical point of view in case of wastewater with high ammonia concentrations, anammox-based technologies are desirable for their treatment. The disadvantage of such systems is slow anammox bacteria growth, which extends an effective technological start-up. Thus, in this study, a fast start-up of the anammox process supported with an anammox-rich inoculum was performed in a sequencing batch reactor (SBR). Using anammox inoculation of SBR laboratory system, the start-up can be fastened to 85 days with 84.5% of nitrogen removal efficacy. The spatial distribution of nitrogen removal bacteria analysed with fluorescent in situ hybridisation revealed that anammox and nitrifiers are located side by side in the flocs and the relative number of ammonia and nitrite oxidisers decreased after 85 days of the experiment

    Prioritization of Biomarker Targets in Human Umbilical Cord Blood: Identification of Proteins in Infant Blood Serving as Validated Biomarkers in Adults

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    Background: Early diagnosis represents one of the best lines of defense in the fight against a wide array of human diseases. Umbilical cord blood (UCB) is one of the first easily available diagnostic biofluids and can inform about the health status of newborns. However, compared with adult blood, its diagnostic potential remains largely untapped

    Cutaneous infection by Mycobacterium haemophilum and kansasii in an IgA-deficient man

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of infections by nontuberculous mycobacteria (NTM) has steadily increased over the past decades, especially in immunocompromised patients.</p> <p>Case presentation</p> <p>We present a patient with IgA-deficiency and mixed cutaneous infection by two slowly growing mycobacteria, <it>Mycobacterium </it>(<it>M.</it>) <it>haemophilum </it>and <it>M. kansasii.</it></p> <p>Conclusions</p> <p>Cutaneous <it>M. haemophilum </it>infections most often result from HIV or transplantation-associated immunosuppression. Rarely, <it>M. haemophilum </it>may also infect healthy patients or iatrogenically immunosuppressed patients without transplantation. <it>M. kansasii </it>is one of the most frequent NTM and large awareness exists about its involvement in human diseases. Mycobacterial diagnosis of cutaneous infections should be considered in long-lasting skin lesions.</p

    Four lectures on secant varieties

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    This paper is based on the first author's lectures at the 2012 University of Regina Workshop "Connections Between Algebra and Geometry". Its aim is to provide an introduction to the theory of higher secant varieties and their applications. Several references and solved exercises are also included.Comment: Lectures notes to appear in PROMS (Springer Proceedings in Mathematics & Statistics), Springer/Birkhause

    Pesticides and health: A review of evidence on health effects, valuation of risks, and benefit‐cost analysis

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    In this paper, we provide reviews of recent scientific findings on health effects and preference valuation of health risks related to pesticides, and the role of benefit‐cost analysis in policies related to pesticides. Our reviews reveal that whereas the focus of the health literature has been on individuals with direct exposure to pesticides, e.g. farmers, the literature on preference elicitation has focused on those with indirect exposure, e.g. consumers. Our discussion of pesticides policies emphasizes the need to clarify the rationale for regulation and the role of risk perceptions in benefit‐cost analysis, and stress the importance of inter‐disciplinary research in this area

    The influence of the landscape structure within buffer zones, catchment land use and instream environmental variables on mollusc communities in a medium-sized lowland river

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    The world’s freshwater molluscan fauna is facing unprecedented threats from habitat loss and degradation. Declines in native populations are mostly attributed to the human impact, which results in reduced water quality. The objectives of our survey were to analyse the structure of the mollusc communities in a medium-sized lowland river and to determine the most important environmental variables at different spatial scales, including landscape structure, catchment land use and instream environmental factors that influence their structure. Our survey showed that a medium-sized river, that flows through areas included in the European Ecological Natura 2000 Network Programme of protected sites, provides diverse instream habitats and niches that support 47 mollusc species including Unio crassus, a bivalve of Community interest, whose conservation requires the designation of a special conservation area under the Habitats Directive Natura 2000. This survey showed that mollusc communities are impacted by several environmental variables that act together at multiple scales. The landscape structure within buffer zones, catchment land use and instream environmental variables were all important and influenced the structure of mollusc communities. Therefore, they should all be taken into consideration in the future restoration of the river, future management projects and programmes for the conservation of biodiversity in running waters. The results of this study may be directly applicable for the rehabilitation of river ecosystems and are recommended to stakeholders in their future decision concerning landscape planning, monitoring species and their habitats, conservation plans and management in accordance with the requirements of sustainable development

    Indoor allergens in settled dust from kindergartens in city of Łódź, Poland

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    Objectives: The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration. Material and Methods: A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children's clothing (N = 36). The samples were collected in springsummer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA). Results: The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001). Conclusions: Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens

    Współczynnik LCI jako podstawowe kryterium oceny zdrowotnej emisji lotnych związków organicznych z wyrobów budowlanych

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    W niniejszym artykule została przedstawiona koncepcja stosowania wartości LCI (ang. Lowest Concentration of Interest) do oceny wpływu na zdrowie emitowanych z wyrobów budowlanych lotnych związków organicznych (LZO). Wartości LCI zostały pierwotnie opracowane przez grupę wiodących europejskich naukowców i opublikowane w 1997 r. w Raporcie nr 18 European Collaborative Action. Obecnie współczynnik ten jest coraz częściej wykorzystywany w przepisach krajów wspólnoty europejskiej do oceny emisji LZO z wyrobów budowlanych. Został również użyty w projekcie klasyfikacji emisji lotnych związków organicznych Komisji Europejskiej

    Izolacja i charakterystyka mikroorganizmów zdolnych do produkcji biosurfaktantów ze środowiska glebowego

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    Biosurfactant production is critical not only from the standpoint of obtaining innovative and relatively cheap surface-active agents but also due to impossibility or limited biodegradation of conventional surfactants obtained by means of chemical syntheses. The main goal of the project was to isolate and characterize (macroscopically and microscopically) microorganisms capable of biosurfactant production and to evaluate the potential of these strains for biosurfactant production from the soil environment contaminated with crude oil products using the methods of conventional microbiology. The focus of the study was on isolation of pure bacteria cultures from soil contaminated with crude oil products sampled from the areas of a petrol station, macroscopic and microscopic identification of the isolated strains and testing their capability of biosurfactant production. It was demonstrated that 2 of 21 strains isolated from soil which was most likely contaminated with crude oil products showed a potential for biosurfactant production. This potential was evaluated by means of the drop collapse, oil spreading and hemolytic assay tests. The study also discussed basic characteristics of biosurfactants and their application in various domains of science and industry.Produkcja biosurfaktantów jest istotna z punktu widzenia nie tylko wytwarzania nowatorskich i względnie tanich środków powierzchniowo czynnych, ale także ze względu na brak możliwości lub bardzo ograniczoną biodegradację tradycyjnych surfaktantów wytwarzanych metodami syntez chemicznych. Głównym celem projektu było wyizolowanie oraz charakterystyka mikro- i makroskopowa mikroorganizmów zdolnych do produkcji biosurfaktantów wraz z oceną zdolności tych szczepów do produkcji biosurfaktantów ze środowiska glebowego zanieczyszczonego substancjami ropopochodnymi z użyciem metod klasycznej mikrobiologii. Zakres badań obejmował izolację czystych kultur bakteryjnych z gleby, zanieczyszczonej substancjami ropopochodnymi, pochodzącej z okolic stacji benzynowej, makro- i mikroskopową identyfikację wyizolowanych szczepów oraz testowanie ich zdolności do produkcji biosurfaktantów. Wykazano, że dwa spośród 21 wyizolowanych szczepów z gleby prawdopodobnie zanieczyszczonej związkami ropopochodnymi ma potencjał w produkcji biosurfaktantów. Zdolność tę oceniano z zastosowaniem testów „drop-collapse”, „oil-spreading” oraz zdolności szczepu do hemolizy. W pracy opisano również podstawowe cechy biosurfaktantów oraz ich zastosowanie w różnych dziedzinach nauki i przemysłu
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