Compost levert complete bemesting

Compost is een zeer goed bemestingsproduct. Het kan kort voor het zaaien worden aangebracht, belemmert de wortelgroei niet en levert een kant-en-klaar ecosysteem als aanvulling en versterking van de bodembiologie. Ook de pH van de bodem en de lucht- en waterhuishouding varen wel bij de toepassing van rijpe compost

Wat is goede compost?

Compost wordt voor meerdere doelen ingezet. Als meststof, maar ook om de organische stofbalans op peil te houden. Maar compost heeft nog meer voordelen. Zo worden aan compost ziektewerende eigenschappen toegekend. Het doel van compostgebruik bepaalt voor een groot deel welke prijs er voor wordt betaald. Maar hoe kan de kwaliteit en daarmee de waarde van compost worden vastgesteld? Om dit te beoordelen is kennis van het eindproduct en vooral ook het composteringsproces nodig. In dit BioKennisbericht geven we richtlijnen voor het vaststellen van compostkwaliteit gerelateerd aan de toepassing

Ocular Pulse Amplitude and Doppler Waveform Analysis in Glaucoma Patients

PURPOSE: To determine the correlation between ocular blood flow velocities and ocular pulse amplitude (OPA) in glaucoma patients using colour Doppler imaging (CDI) waveform analysis. METHOD: A prospective, observer-masked, case-control study was performed. OPA and blood flow variables from central retinal artery and vein (CRA, CRV), nasal and temporal short posterior ciliary arteries (NPCA, TPCA) and ophthalmic artery (OA) were obtained through dynamic contour tonometry and CDI, respectively. Univariate and multiple regression analyses were performed to explore the correlations between OPA and retrobulbar CDI waveform and systemic cardiovascular parameters (blood pressure, blood pressure amplitude, mean ocular perfusion pressure and peripheral pulse). RESULTS: One hundred and ninety-two patients were included [healthy controls: 55; primary open-angle glaucoma (POAG): 74; normal-tension glaucoma (NTG): 63]. OPA was statistically different between groups (Healthy: 3.17 ± 1.2 mmHg; NTG: 2.58 ± 1.2 mmHg; POAG: 2.60 ± 1.1 mmHg; p < 0.01), but not between the glaucoma groups (p = 0.60). Multiple regression models to explain OPA variance were made for each cohort (healthy: p < 0.001, r = 0.605; NTG: p = 0.003, r = 0.372; POAG: p < 0.001, r = 0.412). OPA was independently associated with retrobulbar CDI parameters in the healthy subjects and POAG patients (healthy CRV resistance index: β = 3.37, CI: 0.16-6.59; healthy NPCA mean systolic/diastolic velocity ratio: β = 1.34, CI: 0.52-2.15; POAG TPCA mean systolic velocity: β = 0.14, CI 0.05-0.23). OPA in the NTG group was associated with diastolic blood pressure and pulse rate (β = -0.04, CI: -0.06 to -0.01; β = -0.04, CI: -0.06 to -0.001, respectively). CONCLUSIONS: Vascular-related models provide a better explanation to OPA variance in healthy individuals than in glaucoma patients. The variables that influence OPA seem to be different in healthy, POAG and NTG patients

Naar een optimaal gebruik van biologische mest van kippen en geiten via compostering?

Optimaal gebruik van biologische mest is een cruciale schakel in de overgang naar een 100% biologische keten. Er zijn echter biologische mestsoorten die (nog) moeilijk toe te passen zijn. Denk aan kippenmest die niet op het kippenbedrijf zelf ingezet kan worden of verse stromest van herkauwers die niet op grasland uitgereden kan worden. Voorbehandeling van de mest kan de kwaliteit en het gebruiksgemak echter flink verhogen

Monitoring international migration flows in Europe. Towards a statistical data base combining data from different sources

The paper reviews techniques developed in demography, geography and statistics that are useful for bridging the gap between available data on international migration flows and the information required for policy making and research. The basic idea of the paper is as follows: to establish a coherent and consistent data base that contains sufficiently detailed, up-to-date and accurate information, data from several sources should be combined. That raises issues of definition and measurement, and of how to combine data from different origins properly. The issues may be tackled more easily if the statistics that are being compiled are viewed as different outcomes or manifestations of underlying stochastic processes governing migration. The link between the processes and their outcomes is described by models, the parameters of which must be estimated from the available data. That may be done within the context of socio-demographic accounting. The paper discusses the experience of the U.S. Bureau of the Census in combining migration data from several sources. It also summarizes the many efforts in Europe to establish a coherent and consistent data base on international migration. The paper was written at IIASA. It is part of the Migration Estimation Study, which is a collaborative IIASA-University of Groningen project, funded by the Netherlands Organization for Scientific Research (NWO). The project aims at developing techniques to obtain improved estimates of international migration flows by country of origin and country of destination

Convergence of the all-time supremum of a L\'evy process in the heavy-traffic regime

In this paper we derive a technique of obtaining limit theorems for suprema of L\'evy processes from their random walk counterparts. For each $a>0$, let $\{Y^{(a)}_n:n\ge 1\}$ be a sequence of independent and identically distributed random variables and $\{X^{(a)}_t:t\ge 0\}$ be a L\'evy processes such that $X_1^{(a)}\stackrel{d}{=} Y_1^{(a)}$, $\mathbb E X_1^{(a)}<0$ and $\mathbb E X_1^{(a)}\uparrow0$ as $a\downarrow0$. Let $S^{(a)}_n=\sum_{k=1}^n Y^{(a)}_k$. Then, under some mild assumptions, $\Delta(a)\max_{n\ge 0} S_n^{(a)}\stackrel{d}{\to} R\iff\Delta(a)\sup_{t\ge 0} X^{(a)}_t\stackrel{d}{\to} R$, for some random variable $R$ and some function $\Delta(\cdot)$. We utilize this result to present a number of limit theorems for suprema of L\'evy processes in the heavy-traffic regime

Comparing migration in Britain and Australia: Harmonisation through use of age-time plans

Differences in the way migration is measured impede cross-national comparisons of internal migration. In this paper we utilise age-time diagrams to elucidate these problems for Australia and the United Kingdom and present solutions which generate time series of interregional migration for the two countries, harmonised with respect to age-time plans. We achieve this through estimation of the numbers of migration transitions (Australia) or migration events (Britain) for common age-period-cohort (APC) spaces. We derive appropriate population stocks for computation of transition probabilities or occurrence-exposure rates. In the final section of the paper we present a series of migration-intensity calculations based on varying combinations of period-cohort, period-age, and age-period-cohort perspectives, to demonstrate the significance of the variations, and the errors that can arise without harmonisation

Estimating Population Attribute Values in a Table: “Get Me Started in” Iterative Proportional Fitting

Iterative proportional fitting (IPF) is a technique that can be used to adjust a distribution reported in one data set by totals reported in others. IPF is used to revise tables of data where the information is incomplete, inaccurate, outdated, or a sample. Although widely applied, the IPF methodology is rarely presented in a way that is accessible to nonexpert users. This article fills that gap through discussion of how to operationalize the method and argues that IPF is an accessible and transparent tool that can be applied to a range of data situations in population geography and demography. It offers three case study examples where IPF has been applied to geographical data problems; the data and algorithms are made available to users as supplementary material

GPs views on transfer of information about terminally ill patients to the out-of-hours co-operative

<p>Abstract</p> <p>Background</p> <p>In the Netherlands, the increase in of out-of-hours care that is provided by GP co-operatives is challenging the continuity of care for the terminally ill in general practice. Aim of this study is to investigate the views of general practitioners (GPs) on the transfer of information about terminally ill patients to the GP co-operatives. GPs were asked to give their view from two different perspectives: as a GP in their daily practice and as a locum in the GP co-operative.</p> <p>Methods</p> <p>Retrospective web based questionnaire sent to all 424 GPs in the Amsterdam region.</p> <p>Results</p> <p>With a response rate of 42%, 177 physicians completed the questionnaire. Transfer of information to the GP co-operative about most of their terminally ill patients was reported by 82% of the GPs and 5% did not do so for any of their patients. A faster than foreseen deterioration of the patient's situation was the most frequently reported reason for not transferring information.</p> <p>Of those who transferred information to the GP co-operative, more than 95% reported that they provided information about the diagnosis and terminally ill status of the patient. Information about medication, patient wishes regarding treatment, and prognosis was reported by respectively 90%, 87%, and 74% of the GPs. Less than 50% of the GPs reported that they transferred information about the patient's awareness of both the diagnosis and the prognosis, about the psychosocial context, and intolerances.</p> <p>In their role as locum, over 90% of the GPs wanted to receive information about the diagnosis, the terminally ill status of the patient, the medication and the patient's wishes regarding treatment.</p> <p>Conclusions</p> <p>Although most GPs reported that they transferred information about their terminally ill patients to the GP co-operative, the content of this information varies considerably. Only 21% of the GPs, working out of hours as a locum, were satisfied with the quality of the information transferred.</p