873 research outputs found
Moet er nog zand zijn: een wetenschappelijke kijk op de kustlijn van morgen. Bredene, België, 24 mei 2011: Referatenbundel van de studiedag
Kwantificeren van recente veranderingen in status van amfibieën en hun biotopen in het landelijk gebied: evaluatie en niet-technische samenvatting
Doctor of Pharmacy
dissertationPatients with spinal cord injury often have a complex array of medical probelem. Among the most commonly recognized is the flaccid type of neurogenic bladder dysfunction. This bladder dysfunction predisposes these patient to days or weeks of indwelling or intermittent urethral catherization. Due to the prolonged period during which catheterization is required, these patients are at increased risk of developing recurrent or chronic urinary tract infections. Indwelling catheters and repeated intermittent catheterization produces a continuous bacteriura, even with proper catheter insertion and care. Consequently, microorganisms are able to ascend the urethra and colonize in the bladder. Clinically, it is common to administer agents which keep the colony counts low enough so that the patient does not manifest signs or symptoms of a urinary tract infection. This therapeutic intervention is referred to as a suppressive therapy. Methenamine salts, methenamine mandelate and methenamine hippurate, are among a vareity of pharamacological agents used extensively for this purpose. This study was undertaken to: 1.) Determine in spinal cord injured patients with permanent bladder dysfunction whther any difference exists in the concentration of formaldehyde produced in the urine between two methenamine salts, methenamine mandelate and methenamine hippurate in the commonly used doses; 2.) To determine the concentration of urine formaldehyde attained in spinal cord injured patients with bladder dysfunction during indwelling or intermittent urethral catheterization program; 3.) To determine if concurrent administration of ascorbic acid with the methenamine salts has a significant effect on the levels of formaldehyde produced in the urine
Slak-in-Du project. Inventarisatie van de mollusken in de duingebieden langs de Belgische Kust - 2012 Oostkust
The Slak-in-Du (Snails in the Dunes) project aims at establishing, over a period of about six years, a new inventory of the molluscan fauna in the Belgian coastal dunes area. In the first year of the project the eastern part of the Belgian coast was investigated, i.e. the region east of the harbor of Zeebrugge. About 20 persons have contributed in one way or another. The results are very satisfactorily: A total of 30 species of land snails (among which 5 species of slugs), but also 6 species of freshwater molluscs and 5 species preferring brackish waters were observed. More than half of the species of land snails observed are reported for the first time since 1950 or even for the first time ever for the UTM (Universal Transverse Mercator) 10 x 10 km squares that were investigated, i.e. ES18, ES28 en ES29. The most important of these is undoubtedly Vertigo angustior, a protected species which was found for the first time in more than 50 years at the eastern part of the Belgian coast and for the first time ever in the nature reserve “Het Zwin”. Four other species are reported for the first time in the region that was investigated, i.e. Zonitoides nitidus, Cochlicella acuta, Cernuella cisalpina (= C. jonica) and Alinda biplicata biplicata. The latter had, moreover, never been observed before in the Belgian coastal area. Five species were found rather frequently, i.e. Monacha cantiana, Candidula intersecta, Cernuella virgata, Theba pisana and Cepaea nemoralis. The data that were collected further clearly show that Cochlicella acuta and Theba pisana pisana have by now spread along the entire Belgian coast. On the other hand, several species that are thought to be in decline at the Belgian coast, i.e. Monacha cartusiana, Helicella itala itala, Candidula gigaxii, and Candidula unifasciata unifasciata, have not been observed at all. As only one specimen of Cernuella aginnica was found, also this species is probably in decline. Since only few freshwater habitats occurred in the areas that were investigated in 2012 only a limited number of freshwater species is reported here. Finally, as to brackish water snails, the very rare species Limapontia depressa and Assiminea grayana were found in the “Bay of Heist”, while one specimen of Ecrobia ventrosa was observed alive in the nature reserve “Het Zwin”
Bayesian inference with an adaptive proposal density for GARCH models
We perform the Bayesian inference of a GARCH model by the Metropolis-Hastings
algorithm with an adaptive proposal density. The adaptive proposal density is
assumed to be the Student's t-distribution and the distribution parameters are
evaluated by using the data sampled during the simulation. We apply the method
for the QGARCH model which is one of asymmetric GARCH models and make empirical
studies for for Nikkei 225, DAX and Hang indexes. We find that autocorrelation
times from our method are very small, thus the method is very efficient for
generating uncorrelated Monte Carlo data. The results from the QGARCH model
show that all the three indexes show the leverage effect, i.e. the volatility
is high after negative observations
Adherence to the paediatric immunisation schedule in England
Both adequate coverage and adherence to paediatric immunisation schedules are required for optimal protection against vaccine preventable diseases. We studied the timeliness of routine paediatric vaccinations according to the NHS's immunisation schedule and potential factors of schedule adherence. Immunisation data was obtained from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). We collected vaccine types, doses, and dates for all routine paediatric vaccines between 2008 and 2018: DTaP/IPV/Hib/HepB, DTaP/IPV/Hib, DTaP/IPV, dTaP/IPV, Td/IPV, MMR, PCV, MenB, MenC, MenACWY, Hib/MenC, RV, HPV. Adherence to the immunisation schedule was calculated for each vaccine and dose. Differences in adherence between genders, NHS regions, and IMD quintiles were analysed. Our study included 6'257'828 vaccinations in 1'005'827 children. Seventy-five percent of first doses were administered within one (for vaccines scheduled in the first year of life) or two months (for vaccines scheduled later in life) following the recommended age, 19% too late and 6% too early. About half of the subsequent doses were given timely. The time between first and second doses was too short for 36% of vaccinations while 13% of second doses were administered too long after the first dose. Third doses were administered timely for 45%, too short for 37%, and too long for 18% of vaccinations. Differences in immunisation schedule adherence between girls and boys were negligible, except for HPV, and differences between the four main NHS regions were small. Overall, immunisation schedule adherence improved slightly with decreasing deprivation according to the Index of Multiple Deprivation. Efforts are required to improve the timeliness of paediatric vaccinations and to assure adequate protection against vaccine preventable diseases. We propose developing a compound measure combining coverage and adherence to provide a better indication of the protection against vaccine preventable diseases in a community
Climate reconstruction based on archaeological bivalve shells
Several years of biogeochemical research on bivalve shells yielded in clear proxyrecords carrying potential for reconstruction of paleoseasonal trends in coastal environments. However, the interpretation of the proxy signals is still often problematic. Proxy concentrations can be influenced by several environmental parameters and by physiological processes. With more complex models these problems can be tackled. Two strategies are followed; (1) a statistical black-box model is being developed in parallel with (2) a physiological white-box model.The statistical black-box model can be described as a non-linear multi-proxy model. It is based on chemical measurements in modern bivalve shells and consists of the construction of a curve in a multi-dimensional space. The model describes the variations in the chemical signature of the shell during a full year cycle. The shortest distance from any other data point (e.g. a fossil shell) to the model will give a time point estimation in the annual cycle, which can further be linked to environmental parameters. At present our model approach achieves quite accurate SST reconstructions.A white box model is crucial for understanding the physiological processes and for an unambiguous interpretation of the proxy records. We investigated, in a first phase, in situ the influences of environmental parameters and physiology on the incorporation of proxies in Mytilus edulis at a well documented wave breaker site. In a second phase, in vitro culturing experiments under controlled laboratory conditions were carried out. Experiments were carried out at 8°C and 16°C and at salinities of 18‰ and 28‰. During these experiments mussels were fed under high and low supply regimes. By combining these in situ and in vitro approaches a white box multi-proxy model is generated for the reconstruction of SST and SSS
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