299 research outputs found
Enige oriënterende proeven met Broadleaf P4 worteldip/Phormizakken toegepast bij coniferen en heesters in de aanlegfase : is worteldip al dan niet met toepassing van Phormizakken een alternatief voor het traditionele kluiten?
Veel boomkwekerijproducten worden ingegaasd met een acryl-gaaslap. Weliswaar bestaan er ook jute gaaslappen, maar in de praktijk wenst de klant van de boomkwekers in 95% van de gevallen een acryl-gaaslap. Deze lappen zijn een bron van milieuverontreiniging, doordat ze niet afbreken in de grond. Tevens gaat er met het kluiten een aanzienlijke hoeveelheid grond het land af, waaronder organische stof. Dit moet weer aangevuld worden. Uit onderzoek in binnen- en buitenland is bekend dat Broadleaf P4 granulaat en worteldip positief uit kunnen werken op een gewas. Het doel van de in 2000 uitgevoerde proeven was dan ook te onderzoeken of Broadleaf P4 worteldip een goede vervanger zou kunnen zijn voor de traditionele kluit. Ook plastic Phormizakken werden in de proeven meegenomen. De proeven werden te Boskoop en Horst uitgevoerd. In Horst alleen met Thuja occidentalis âBrabantâ. Te Boskoop werd gewerkt met Prunus laurocerasus âOtto Luykenâ en een conifeer: Thuja occidentalis âSmaragdâ (voorjaar) resp. Th. occ. âBrabantâ (najaar). Boskoop betreft veengrond; Horst is zandgrond. De proeven werden in voor- en najaar ingeplant. Worteldip werd direct na oprooien middels dippen aangebracht. Vervolgens bleven de planten 4 tot 14 dagen liggen onder dekzeil. Dit is niet gebruikelijk in de praktijk tot nu toe. De proef te Boskoop in het voorjaar werd uitgevoerd met hele, halve, geen kluit en gedipt in worteldip. De najaarsproef te Boskoop en beide proeven te Horst werden uitgevoerd met kluit/ kluit + Phormizak/ kluit + worteldip/ etc. Uit de resultaten blijkt dat worteldip en/of Phormizak geen goede vervanger is voor de traditionele kluit. De behandelingen kluit en kluit + Phormizak behaalden altijd de beste resultaten. Worteldip doet wel iets: logisch want uit de literatuur was al duidelijk geworden dat Broadleaf P4 wel degelijk een werking heeft. De reden waarom worteldip niet 100% werkte kan de volgende zijn: de planten hadden alle een dicht vertakte goede wortelpruik. De gel van worteldip kon niet doordringen tot in de kern van de wortelpruik. Kortom: alleen de buitenste wortels waren beschermd tegen uitdrogen. Samenvattend waren de conclusies uit dit onderzoek: Uit de in dit rapport gemelde proeven lijkt de conclusie gerechtvaardigd dat planten die met kluit of met kluit + zak worden verhandeld betere aanslagkansen hebben dan coniferen en sierheesters die zonder kluit worden verhandeld. Broadleaf worteldip al dan niet in combinatie met Phormizak heeft wel enig effect: planten die op een dergelijke manier worden behandeld direct na oprooien doen het beter dan planten met kale wortel zonder enige vorm van bescherming. Hoe korter planten worden bewaard, des te beter is dit voor kans van slagen van de aanplant. Verschillen tussen kluit, kluit + zak en de rest lijken bij in het najaar uitplanten groter te zijn dan bij het in voorjaar uitplanten. Bij het in najaar uitplanten kan er na de winter sterfte optreden bij de planten die zonder kluit zijn uitgeplant
Exact results for the reactivity of a single-file system
We derive analytical expressions for the reactivity of a Single-File System
with fast diffusion and adsorption and desorption at one end. If the conversion
reaction is fast, then the reactivity depends only very weakly on the system
size, and the conversion is about 100%. If the reaction is slow, then the
reactivity becomes proportional to the system size, the loading, and the
reaction rate constant. If the system size increases the reactivity goes to the
geometric mean of the reaction rate constant and the rate of adsorption and
desorption. For large systems the number of nonconverted particles decreases
exponentially with distance from the adsorption/desorption end.Comment: 4 pages, 2 figure
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Integration of pneumatic fracturing and in situ vitrification in the soil subsurface
Pacific Northwest Laboratory is evaluating ways to increase the applicability of the in situ vitrification (ISV) process at hazardous and radioactive waste sites. One innovation is the placement of a conductive material that will facilitate initiating the ISV process at a target depth. A series of laboratory tests performed at the New Jersey Institute of Technology (NJIT) assessed the feasibility of pneumatic fracturing (PF) in the highly permeable soils of the Hanford Site. The NJIT tests included an analysis of Hanford soils, a series of PF injection tests, and a parametric analysis to determine how soil properties affect the PF process. Results suggest that the PF process can be applied to Hanford soils and that dry medium (e.g., conductive material such as graphite flake) can be injected into the fracture. This paper describes the laboratory testing performed at NJIT, its results, and the application of those results to plans for a field demonstration at Hanford
Associations of university student life challenges with mental health and self-rated health: A longitudinal study with 6 months follow-up
Background: Mental health problems are highly prevalent among university students. Stress due to student life challenges may be a risk factor for poorer health. This study investigates to what extent student life challenges and changes therein are associated with mental health and self-rated health. Methods: In a longitudinal study with 568 Italian university students mental health was assessed using the Mental Health Inventory-5 (MHI-5) and self-rated health with a single item from the Short Form 36 Health Survey (SF36) (score ranges: 0-100) at baseline and at six months follow-up. Student life challenges were investigated using six subscales (score ranges: 1-4) of the Higher Education Stress Inventory (HESI). A between-within linear regression model was used to investigate whether a higher exposure to life challenges was associated with poorer health (between individuals) and whether changes in student life challenges were associated with changes in health (within individuals). Results: Higher exposure to student life challenges was associated with poorer mental health (b ranging from -5.3 to -10.3) and self-rated health (b ranging from -3.1 to -9.6). An increase in student life challenges within individuals was associated with poorer mental health and self-rated health, in particular for high workload (b up to -5.9), faculty shortcomings (b up to -5.7), and unsupportive climate (b up to -5.6). Discussion: Exposure to student life challenges and changes therein are associated with university studentsâ health. Our findings suggest that student life challenges may be a target for interventions to improve mental health and self-rated health among university students
Associations of university student life challenges with mental health and self-rated health:A longitudinal study with 6 months follow-up
BACKGROUND: Mental health problems are highly prevalent among university students. Stress due to student life challenges may be a risk factor for poorer health. This study investigates to what extent student life challenges and changes therein are associated with mental health and self-rated health. METHODS: In a longitudinal study with 568 Italian university students mental health was assessed using the Mental Health Inventory-5 (MHI-5) and self-rated health with a single item from the Short Form 36 Health Survey (SF36) (score ranges: 0-100) at baseline and at six months follow-up. Student life challenges were investigated using six subscales (score ranges: 1-4) of the Higher Education Stress Inventory (HESI). A between-within linear regression model was used to investigate whether a higher exposure to life challenges was associated with poorer health (between individuals) and whether changes in student life challenges were associated with changes in health (within individuals). RESULTS: Higher exposure to student life challenges was associated with poorer mental health (b ranging from -5.3 to -10.3) and self-rated health (b ranging from -3.1 to -9.6). An increase in student life challenges within individuals was associated with poorer mental health and self-rated health, in particular for high workload (b up to -5.9), faculty shortcomings (b up to -5.7), and unsupportive climate (b up to -5.6). DISCUSSION: Exposure to student life challenges and changes therein are associated with university students' health. Our findings suggest that student life challenges may be a target for interventions to improve mental health and self-rated health among university students
Does reduced employment protection increase the employment disadvantage of workers with low education and poorer health?
Background Declines in employment protection may have disproportionate effects on employment opportunities of workers with low education and poorer health. This study investigates the impact of changes in employment protection levels on employment rates according to education and health in 23 European countries. Methods Data were taken from the 4-year rotating panel European Union Statistics on Income and Living Conditions study. Employed participants aged 29-59 years (n = 334 999) were followed for 1 year over an 11-year period, from 2003 up to 2014. A logistic regression model with country and period fixed effects was used to estimate the association between changes in the Organisation for Economic Co-operation and Development (OECD) employment protection index and labour market outcomes, incorporating interaction terms with education and health. Results 15 of the 23 countries saw their level of employment protection decline between 2003 and 2014. Reduced employment protection of temporary workers increased odds of early retirement (OR 6.29, 95% CI 3.17 to 12.48) and unemployment (OR 1.37, 95% CI 1.07 to 1.76). Reduced employment protection of permanent workers increased odds of early retirement more among workers in poor health (OR 4.46, 95% CI 2.26 to 8.78) than among workers in good health (OR 2.58, 95% CI 1.30 to 5.10). The impact of reduced employment protection of temporary workers on unemployment was stronger among lower-educated workers (OR 1.47, 95% CI 1.13 to 1.90) than among higher-educated workers (OR 1.21, 95% CI 0.95 to 1.54). Conclusion Reduced employment protection increased the odds of early exit from paid employment, especially among workers with lower education and poorer health. Employment protection laws may help reduce the employment disadvantage of workers with low education and poorer health
Changes in physical health among participants in a multidisciplinary health programme for long-term unemployed persons
Background. The relationship between poor health and unemployment is well established. Health promotion among unemployed persons may improve their health. The aims of this study were to investigate characteristics of non-participants and drop-outs in a multidisciplinary health promotion programme for long-term unemployed persons with health complaints, to evaluate changes in physical health among participants, and to investigate determinants of improvement in physical health. Methods. A longitudinal, non-controlled design was used. The programme consisted of two weekly exercise sessions and one weekly cognitive session during 12 weeks. The main outcome measures were body mass index, blood pressure, cardiorespiratory fitness, abd
Preventing Nerve Function Impairment in Leprosy: Validation and Updating of a Prediction Rule
Leprosy is caused by a bacterium that attacks the peripheral nerves. This may cause nerve function impairment (NFI), resulting in handicaps and disabilities. Therefore, prediction and prevention of NFI is extremely important in the management of leprosy. In 2000, a prediction rule for NFI was published, but circumstances have changed since the study was performed in the 1990s: the leprosy detection delay has shortened and the definition of NFI has changed. The original rule used âleprosy classificationâ and âNFI present at diagnosisâ to predict future NFI. In the current patient population we studied an adjusted rule based on âleprosy classificationâ and âpresence of antibodiesâ. This adjusted rule predicted NFI more often than the original rule. With the adjusted rule it is now also possible to assess NFI risk before the first nerve damage event takes place. This may help doctors and health workers to improve surveillance for people at high risk. Early detection and treatment can then prevent permanent disabilities
Identification of the factors associated with outcomes in a condition management programme
<p>Background: A requirement of the Governmentâs Pathways to Work (PtW) agenda was to introduce a Condition Management Programme (CMP). The aim of the present study was to identify the differences between those who engaged and made progress in this telephone-based biopsychosocial intervention, in terms of their health, and those who did not and to determine the client and practitioner characteristics and programme elements associated with success in a programme aimed at improving health.</p>
<p>Methods: Data were obtained from the CMP electronic spreadsheets and clients paper-based case records. CMP
standard practice was that questionnaires were administered during the pre- and post-assessment phases over the
telephone. Each clientâs record contains their socio-demographic data, their primary health condition, as well as the pre- and post-intervention scores of the health assessment tool administered. Univariate and multivariate statistical analysis was used to investigate the relationships between the database variables. Clients were included in the study if their records were available for analysis from July 2006 to December 2007.</p>
<p> Results: On average there were 112 referrals per month, totalling 2016 referrals during the evaluation period. The
majority (62.8%) of clients had a mental-health condition. Successful completion of the programme was 28.5% (575
âcompletersâ; 144 âdischargesâ). Several factors, such as age, health condition, mode of contact, and practitioner
characteristics, were significant determinants of participation and completion of the programme. The results
showed that completion of the CMP was associated with a better mental-health status, by reducing the number of
clients that were either anxious, depressed or both, before undertaking the programme, from 74% to 32.5%.</p>
<p>Conclusions: Our findings showed that an individual's characteristics are associated with success in the
programme, defined as completing the intervention and demonstrating an improved health status. This study
provides some evidence that the systematic evaluation of such programmes and interventions could identify ways
in which they could be improved.</p>
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