462 research outputs found

    Management of Biesboch reservoirs for quality control with special reference to eutrophication

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    The three Biesbosch Reservoirs are pumped storage reservoirs, fed with rather polluted and highly eutrophic water from the River Meuse. Air injection at the bottom of the reservoirs prevents thermal stratification, which would otherwise result in serious water quality deterioration. Reservoir mixing also serves as an economic algal control measure; mixing over sufficient depth causes light to play the role of limiting factor and this, combined with zooplankton grazing, keeps the biomass of phytoplankton at acceptable levels. Special problems are caused by benthic, geosmin-producing Oscillatoria species growing on the inner embankment. Rooting up the bottom with a harrow is used as the method of control, based on underwater observations by biological staff trained as SCUBA-divers. With regard to pollutant behaviour the three reservoirs act as a series of fully mixed reactors. This enables the application of kinetic models to describe their behaviour and allows the use of a selective intake policy, e.g. for suspended solids with associated contaminants, ammonia and polynuclear aromatic hydrocarbons. A combination of selective intake and self- purification processes - enhanced by the compartmentalisation of the storage volume in three reservoirs - leads to a striking improvement for many water-quality parameters

    Bijbelse voornamen

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    De wereldvraag naar zuivelproducten uit de EG en de betekenis voor het afzetbeleid van de Gemeenschap

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    De publikatie geeft de belangrijkste resultaten weer van een onderzoek naar de vraag door niet-EG-landen naar zuivelprodukten uit de Gemeenschap, waarvan een volledig onderzoeksverslag eerder verscheen onder de naam "Analyse van de wereldvraag naar zuivelprodukten uit de EG". De publikatie is vooral bedoeld om beleidsmakers te informeren over de uitkomsten van het onderzoek en de daaruit te trekken konklusies voor het te voeren afzetbeleid. In het onderzoek is nagegeaan hoe het exportvolume van de EG reageert op een verandering van de exportprijzen. Veel aandacht is er voor de dominante positie van de EG op de wereldzuivelmarkt en de daaruit voortvloeiende konsekwenties voor het uitvoerbeleid. Voorts wordt aan de orde gesteld het onderscheid tussen een afzetbeleid met zo weinig mogelijk lasten voor het EG-budget en een beleid dat zo veel mogelijk bijdraagt aan de welvaart in de Gemeenscha

    Analyse van de wereldvraag naar zuivelprodukten uit de EG

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    Het verslag bevat het resultaat van een onderzoek naar ontwikkelingen in de uitvoer van zuivelprodukten uit de EG en Nederland naar niet-EG-landen in de periode 1974-1980. Met name is bestudeerd de relatie tussen de uitgevoerde hoeveelheden produkt en de prijs waartegen de EG zuivelprodukten op de wereldmarkten aanbiedt. Van deze relatie zijn met behulp van regressie-analyse schattingen gemaakt. Het empirisch onderzoek wordt voorafgegaan door een theoretische analyse van de werking van de wereldzuivelmarkt en van optimaal restitutiebeleid onder verschillende omstandighede

    Rejection of the name Borreliella gen. nov. and all proposed species comb. nov. placed therein. Request for an opinion

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    Rejection (nomen rejiciendum) of the name Borreliella gen. nov. and all new combinations therein is being requested on grounds of risk to human health and patient safety (Principle 1, subprinciple 2 and Rule 56a) and violation to aim for stability of names, avoid useless creation of names (Principle 1, subprinciple 1 and 3) and that names should not be changed without sufficient reason (Principle 9 of the Code)

    The genus Borrelia reloaded

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    The genus Borrelia, originally described by Swellengrebel in 1907, contains tick- or louse-transmitted spirochetes belonging to the relapsing fever (RF) group of spirochetes, the Lyme borreliosis (LB) group of spirochetes and spirochetes that form intermittent clades. In 2014 it was proposed that the genus Borrelia should be separated into two genera; Borrelia Swellengrebel 1907 emend. Adeolu and Gupta 2014 containing RF spirochetes and Borreliella Adeolu and Gupta 2014 containing LB group of spirochetes. In this study we conducted an analysis based on a method that is suitable for bacterial genus demarcation, the percentage of conserved proteins (POCP). We included RF group species, LB group species and two species belonging to intermittent clades, Borrelia turcica Güner et al. 2004 and Candidatus Borrelia tachyglossi Loh et al. 2017. These analyses convincingly showed that all groups of spirochetes belong into one genus and we propose to emend, and re-unite all groups in, the genus Borrelia

    Lower Extremity Amputation Rates in People With Diabetes Mellitus:A Retrospective Population Based Cohort Study in Zwolle Region, The Netherlands

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    OBJECTIVE: Lower extremity amputations are a major complication of diabetes mellitus (DM). In a previous Dutch study, the incident rate of major amputations was 89.2 per 100 000 person years. The primary aim of this study was to describe the lower extremity amputation rates in people with DM in the Zwolle region, where preventive and curative footcare is organised according to the guidelines of the International Working Group of the Diabetic Foot (IWGDF). The secondary aim was to evaluate outcomes and underlying characteristics of these people.METHODS: This was a retrospective regional population based cohort study. Data from all people with DM treated in primary and secondary care, living in the region Zwolle were collected. All amputations in the period 2017 to 2019 were analysed. Comparisons were made between those with and without an amputation.RESULTS: In the analysis 5 915 people with DM were included, with a mean age of 67.8 (IQR 57.9, 75.9) years. Of those people, 47% were women and the median HbA1c was 53 (IQR 47, 62) mmol/mol. Over the three year study period, a total of 68 amputations were performed in 59 people: 46 minor, 22 major. This translated into an average annual crude amputation incidence rate of non-traumatic major and minor amputations of 41.5 and 86.9 per 100 000 person years among people with diabetes. Compared with those not undergoing amputations, those who underwent an amputation were more often men, older, mainly had T2DM, were treated in secondary care, had higher diastolic blood pressure, worse diabetic footcare profile, longer DM duration and higher HbA1c. At the end of the follow up, 111 people died: 96 (1.6%) without and 15 (25.4%) with amputations (p &lt; .001).CONCLUSIONS: This retrospective study provides detailed insight into the rate of amputations in Dutch people with diabetes in the region Zwolle. Compared with previous Dutch estimates, these data suggest a considerable decrease in major amputation incidence rate.</p

    A Qualitative Exploration of Social Contact Patterns Relevant to Airborne Infectious Diseases in Northwest Bangladesh

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    In South Asia, the burden of infectious diseases is high. Socioeconomically and culturally-defined social interaction patterns are considered to be an important determinant in the spread of diseases that are transmitted through person-to-person contact. Understanding of the contact patterns in this region can be helpful to develop more effective control measures. Focus group discussions were used in exploring social contact patterns in northwest Bangladesh. The patterns were assessed for perceived relevance to the spread of airborne infectious diseases, with special focus on diseases, like leprosy and tuberculosis, in which the role of social determinants is well-recognized. Highly-relevant social contact patterns inside the home and the neighbourhood, across age and sex groups, were reported in all group discussions. Outside the home, women and girls reported relevant contacts limited to the close neighbourhood while men mentioned high relevant contacts beyond. This implies that, in theory, infectious diseases can easily be transmitted across age and sex groups in and around the home. Adult men might play a role in the transmission of airborne infectious diseases from outside this confined area since only this group reported highly-relevant social contacts beyond the home. This concept needs further exploration but control programmes in the South Asian region could benefit from considering differences in social contact patterns by gender for risk assessments and planning of preventive interventions
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