141 research outputs found
Perspectieven voor hoogveenherstel in Nederland : samenvatting onderzoek en handleiding hoogveenherstel 1998-2010
Het hoogveenareaal in Nederland is door ontginning, turfwinning, boekweitbrandcultuur en verdroging sterk gereduceerd. De water- en nutriĂ«ntenhuishouding van de hoogvenen zijn sterk verstoord door deze aantastingen en bovendien door de neerslag van atmosferisch stikstof (N). Verder is door deze aantastingen de variatie in terreincondities die aanwezig is in intacte hoogveenlandschappen, met name gradiĂ«nten van de zure, mineraalarme hoogveenkern naar de gebufferde, mineraalrijkere omgeving, afgenomen. Herstelmaatregelen in de hoogveenrestanten hadden wisselend succes: soms herstelden of ontwikkelden zich vegetaties met bultvormende veenmossen, meestal ontstond een drijvende laag Waterveenmos (Sphagnum cuspidatum) of een zure waterplas. Verder bleef Pijpenstrootje (Molinia caerulea) over grote oppervlakten de vegetatie domineren en vestigden zich Berken (Betula spec.). In het kader van het kennisnetwerk âOntwikkeling en Beheer Natuurkwaliteitâ (OBN) is onderzoek gedaan naar de perspectieven voor hoogveenherstel in Nederland. Twee vragen stonden daarbij centraal: 1. Is hoogveenherstel mogelijk bij de huidige hoge atmosferische N-depositie? 2. Onder welke voorwaarden is succesvol herstel van de karakteristieke flora en fauna mogelijk? De belangrijkste conclusies uit dit onderzoek worden in dit rapport beschreven
Samenvatting en synthese: perspectieven voor hoogveenherstel in Nederland
De gebrekkige kennis over hoe in Nederland hoogvenen hersteld moeten worden waren voor de Directie Natuurbeheer van het ministerie van LNV en het EC-LNV aanleiding om in het kader van de regeling Overlevingsplan Bos & Natuur een subsidie beschikbaar te stellen voor onderzoek naar hoogveenherstel in Nederland. In eerste instantie is het preadvies samengesteld waarin de bestaande kennis bijeengebracht is en benodigd onderzoek geformuleerd is (Schouwenaars et al. 1997). Op basis van het preadvies zijn keuzes gemaakt waarbij uiteindelijk de meeste knellende kennislacunes geprioriteerd werden voor de eerste onderzoeksfase. Dit betekent dat niet alle vragen die voor het beheer en herstel van hoogvenen van belang kunnen zijn aan bod zijn gekomen. In deze eerste fase heeft nog erg de nadruk gelegen op het beheren en herstellen van de typische hoogveenvegetaties, omdat deze, zoals hierna zal worden uitgelegd, de basis vormen voor een goed functionerend hoogveensysteem
Participation and satisfaction after spinal cord injury: results of a vocational and leisure outcome study
Study design: Survey. Objectives: Insight in (1) the changes in participation in vocational and leisure activities and (2) satisfaction with the current participation level of people with spinal cord injuries (SCIs) after reintegration in society. Design: Descriptive analysis of data from a questionnaire. Setting: Rehabilitation centre with special department for patients with SCIs, Groningen, The Netherlands. Subjects: A total of 57 patients with traumatic SCI living in the community, who were admitted to the rehabilitation centre two to 12 years before the current assessment. Main outcome measures: Changes in participation in activities; current life satisfaction; support and unmet needs. Results: Participation expressed in terms of hours spent on vocational and leisure activities changed to a great extent after the SCI. This was mainly determined by a large reduction of hours spent on paid work. While 60% of the respondents successfully reintegrated in work, many changes took place in the type and extent of the job. Loss of work was partially compensated with domestic and leisure activities. Sports activities were reduced substantially. The change in participation level and compensation for the lost working hours was not significantly associated with the level of SCI-specific health problems and disabilities. As was found in other studies, most respondents were satisfied with their lives. Determinants of a negative life satisfaction several years following SCI were not easily indicated. Reduced quality of life was particularly related to an unsatisfactory work and leisure situation. Conclusions: Most people with SCI in this study group were able to resume work and were satisfied with their work and leisure situation
Vooronderzoek Wierdense Veld : Eindrapportage mei 2005
In dit eindrapport van het vooronderzoek Wierdense Veld worden eerst de belangrijkste resultaten van de afzonderlijke onderdelen besproken (Hoofdstuk 2 tot en met 6). In hoofdstuk 2 komt de regionaal-hydrologische situatie van het Wierdense Veld aan de orde en in hoofdstuk 3 de interne hydrologie van het Wierdense Veld. Het hydrochemisch onderzoek staat beschreven in hoofdstuk 4 en de vegetatiekarterting in hoofdstuk 5. De watermacrofauna komt aan de orde in hoofdstuk 6. Hoofdstuk 7 bevat de aanbevelingen voor herstelmaatregelen en een voorstel voor de monitoring van de maatregelen staat beschreven in hoofdstuk 8
White matter microstructure disruption in early stage amyloid pathology.
Introduction: Amyloid beta (AÎČ) accumulation is the first pathological hallmark of Alzheimer's disease (AD), and it is associated with altered white matter (WM) microstructure. We aimed to investigate this relationship at a regional level in a cognitively unimpaired cohort. Methods: We included 179 individuals from the European Medical Information Framework for AD (EMIFâAD) preclinAD study, who underwent diffusion magnetic resonance (MR) to determine tractâlevel fractional anisotropy (FA); mean, radial, and axial diffusivity (MD/RD/AxD); and dynamic [18F]flutemetamol) positron emission tomography (PET) imaging to assess amyloid burden. Results: Regression analyses showed a nonâlinear relationship between regional amyloid burden and WM microstructure. Low amyloid burden was associated with increased FA and decreased MD/RD/AxD, followed by decreased FA and increased MD/RD/AxD upon higher amyloid burden. The strongest association was observed between amyloid burden in the precuneus and body of the corpus callosum (CC) FA and diffusivity (MD/RD) measures. In addition, amyloid burden in the anterior cingulate cortex strongly related to AxD and RD measures in the genu CC. Discussion: Early amyloid deposition is associated with changes in WM microstructure. The nonâlinear relationship might reflect multiple stages of axonal damage
Onderzoek ten behoeve van herstel en beheer van Nederlandse hoogvenen: eindrapportage 1998-2001
Eindrapport (1998-2001) van het onderzoeksprogramma OBN hoogvenen. In 1998 is dit project, getiteld âOnderzoek ten behoeve van herstel en beheer van Nederlandse hoogvenenâ, gestart. Het onderzoek werd uitgevoerd door een consortium gevormd door de Katholieke Universiteit Nijmegen (leerstoelgroep Aquatische Ecologie en Milieubiologie en afdeling Dierecologie), Wageningen Universiteit (leerstoelgroep Natuurbeheer en Plantenecologie & leerstoelgroep Waterhuishouding), Stichting Bargerveen en het Nederlands Instituut voor Toegepaste Natuurwetenschappen (NITG-TNO). Het project werd uitgevoerd in opdracht van het Expertisecentrum LNV (EC-LNV) van het ministerie van Landbouw, Natuurbeheer en Visserij. In deze voorlopige eindrapportage worden de belangrijkste resultaten gepresenteerd van het onderzoeksprogramma
Changes in vegetation and soil characteristics in coastal sand dunes along a gradient of atmospheric nitrogen deposition
A field survey was conducted to detect signals of atmospheric nitrogen (N) in 11 dune systems along a nitrogen deposition gradient in the United Kingdom. In the mobile and semi-fixed dunes, above-ground biomass was positively related to N inputs. This increase was largely due to increased height and cover of Ammophila arenaria. In the long term, this increased biomass may lead to increased organic matter accumulation and consequently accelerated soil development. In the fixed dunes, above ground biomass also showed a positive relationship with N inputs as did soil C : N ratio while soil available N was negatively related to N inputs. Plant species richness was negatively related to N inputs. In the dune slacks, while soil and bulk vegetation parameters showed no relationship with N inputs, cover of Carex arenaria and Hypochaeris radicata increased. Site mean Ellenberg N numbers showed no relationship with N deposition either within habitats or across the whole dataset. Neither abundance-weighting nor inclusion of the Siebel numbers for bryophytes improved the relationship. The survey reveals that the relationships of soil and vegetation with atmospheric N deposition vary between sand dune habitats but, despite this variability, clear correlations with N inputs exist. While this survey cannot establish causality, on the basis of the relationships observed we suggest a critical load range of 10 - 20 kg N ha(-1) yr(-1) for coastal sand dunes in the UK
Identification of a sheath-associated protein involved in phosphate transport in Sphaerotilus natans
Sphaerotilus natans was shown to have a fourfold lower KâČ m of phosphate transport when grown in medium containing 0.1 m m phosphate, compared to cells grown in 10.0 m m phosphate. Analysis of sheath proteins from cells grown at these two phosphate levels revealed a protein of 53 kDa present in the sheath of cells grown at a phosphate concentration of 0.1 m m . This sheath-associated, phosphate-regulated protein, designated SapP, was gel purified and used to raise a polyclonal antibody. Enzyme-linked immunosorbent assay was used to localize this protein to the surface of the sheathed cells. Phosphate uptake assays done in the presence of the antibody also showed a rise in the KâČ m of phosphate transport in cells grown in 0.1 m m phosphate, indicating that this protein is involved in high-affinity phosphate transport.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46762/1/253_2004_Article_BF00166797.pd
Increased masticatory activity and quality of life in elderly persons with dementia-a longitudinal matched cluster randomized single-blind multicenter intervention study.
Background: Worldwide, millions of people are suffering from dementia and this number is rising. An index of quality of life (QoL) can describe the impact a disease or treatment has on a person's wellbeing. QoL comprises many variables, including physical health and function, and mental health and function. QoL is related to masticatory ability and physical activity. Animal studies show that disruption of mastication due to loss of teeth or a soft diet leads to memory loss and learning problems. Since these are common complaints in dementia, it is hypothesized that improvement of masticatory function and normalization of diet consistency can increase QoL in elderly persons suffering from dementia. Therefore, the goal of the present study is to examine whether an increase in masticatory activity, achieved by increased food consistency and enhancement of masticatory function through improved oral health care has a positive effect on QoL, including cognition, mood, activities of daily living (ADL), and circadian rhythm in elderly persons with dementia.Methods and design: The described study is a prospective longitudinal matched cluster randomized single-blind multicenter study. Participants are elderly persons living in the Netherlands, suffering from dementia and receiving psychogeriatric care. An intervention group will receive improved oral health care and a diet of increased consistency. A control group receives care as usual. Participants will be assessed four times; outcome variables besides QoL are cognition, mood, independence, rest-activity rhythm, blood pressure, and masticatory function.Discussion: This research protocol investigates the effect of an intervention executed by daily caregivers. The intervention will increase masticatory activity, which is achieved by three different actions, (providing oral health care, increasing food consistency, or a combination of both). There is a certain amount of variety in the nature of the interventions due to local differences in nursing homes. This might be a scientific weakness in the study design; however, a practical implementation of any findings will be subject to the same factors, making this study design clinically relevant.Trial registration: NTR1561. © 2013 Weijenberg et al.; licensee BioMed Central Ltd
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