Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 7 )

2018 ( 45 )

2017 ( 34 )

2016 ( 48 )

Custom range...

Search Results: 1 - 10 of 33940 matches for " Caty van den Hoek "
All listed articles are free for downloading (OA Articles)
Page 1 /33940
Display every page Item
Using Intervention Mapping to develop a programme to prevent sexually transmittable infections, including HIV, among heterosexual migrant men
Mireille EG Wolfers, Caty van den Hoek, Johannes Brug, Onno de Zwart
BMC Public Health , 2007, DOI: 10.1186/1471-2458-7-141
Abstract: First a needs assessment was carried out. Then, a literature review was done, key figures were interviewed and seven group discussions were held. Subsequently, the results were translated into specific objectives ("change objectives") and used in intervention development for two subgroups: men with an Afro-Caribbean background and unmarried men with a Turkish and Moroccan background. A matrix of change objectives was made for each subgroup and suitable theoretical methods and practical strategies were selected. Culturally-tailored interventions were designed and were pre-tested among the target groups.This development process resulted in two interventions for specific subgroups that were appreciated by both the target groups and the migrant prevention workers. The project took place in collaboration with a university center, which provided an opportunity to get expert advice at every step of the Intervention Mapping process. At relevant points of the development process, migrant health educators and target group members provided advice and feedback on the draft intervention materials.This intervention development project indicates that careful well-informed intervention development using Intervention Mapping is feasible in the daily practice of the MPHS, provided that sufficient time and expertise on this approach is available. Further research should test the effectiveness of these interventions.The number of registered new sexually transmitted infections (STI) in the Netherlands has been increasing for several years [1], and reinforcement and extension of preventive actions is necessary. In the Netherlands, as well as in other Western European countries, ethnic minority groups originating from countries with a high prevalence of heterosexually transmitted HIV (Sub-Saharan Africa, Caribbean region) have higher HIV incidence levels. These groups are therefore recognized as important target populations for prevention [1-4]. Heterosexual migrant men are a priority gro
New theoretical yields of intermediate mass stars
Bob van den Hoek,Martin Groenewegen
Physics , 1996,
Abstract: We present theoretical yields of H, $^{4}$He, $^{12}$C, $^{13}$C, $^{14}$N, and $^{16}$O for stars with initial masses between 0.8 and 8 M$_{\odot}$ and initial metallicities Z = 0.001, 0.004, 0.008, 0.02, and 0.04. We use the evolutionary tracks of the Geneva group up to the early asymptotic giant branch (AGB) in combination with a synthetic thermal-pulsing AGB evolution model to follow in detail the chemical evolution and mass loss up to the end of the AGB including the first, second, and third dredge-up phases. Most of the relations used are metallicity dependent to make a realistic comparison with stars of different initial abundances. The effect of Hot Bottom Burning (HBB) is included in an approximate way. The free parameters in our calculations are the mass loss scaling parameter $\eta_{AGB}$ for stars on the AGB (using a Reimers law), the minimum core mass for dredge-up M$_{c}^{min}$, and the third dredge-up efficiency $\lambda$. As derived from previous extensive modeling, $\eta_{AGB}$ = 4, M$_{c}^{min}$ = 0.58 \mss, and $\lambda = 0.75$ including HBB are in best agreement with observations of AGB stars both in the Galactic disk and the Magellanic Clouds. We compare the abundances predicted during the final stages of the AGB with those observed in planetary nebulae in the Galactic disk and show that the model with the aforementioned parameters is in good agreement with the observations. The metallicity dependent yields of intermediate mass stars presented in this paper are well suited for use in galactic chemical evolution models.
Inhomogeneous chemical evolution of the Galactic disk: evidence for sequential stellar enrichment?
Bob van den Hoek,Teije de Jong
Physics , 1996,
Abstract: We investigate the origin of the abundance variations observed among similarly aged F and G dwarfs in the local Galactic disk. We present arguments in support of combined infall of metal-deficient gas and sequential enrichment by successive stellar generations in the local Galactic disk ISM. We show that galactic chemical evolution models which take into account these processes simultaneously are consistent with both the observed abundance variations among similarly aged dwarfs in the solar neighbourhood and the abundances observed in the local disk ISM. For reasonable choices of parameters, these models can reproduce variations in [M/H] for individual elements M = C, O, Fe, Mg, Al, and Si as well as the scatter observed in abundance-abundance relations like [O/Fe]. For the same models, the contribution of sequential stellar enrichment to the magnitude of the observed abundance variations can be as large as 50%. We discuss the impact of sequential stellar enrichment and episodic infall of metal-deficient gas on the inhomogeneous chemical evolution of the Galactic disk.
Modelling the spectro-photometric and chemical evolution of Low Surface Brightness spiral galaxies
L. B. van den Hoek,W. J. G. de Blok
Physics , 1995,
Abstract: We investigate the star formation history and chemical evolution of Low Surface Brightness (LSB) spiral galaxies by means of their observed spectro-photometric and chemical properties. We present preliminary results for Johnson-Cousins UBVRI magnitudes and stellar [O/H] abundance ratios using a galactic chemical evolution model incorporating a detailed metallicity dependent set of stellar input data covering all relevant stages of stellar evolution. Comparison of our model results with observations confirms the idea that LSB galaxies are relatively unevolved systems. However, we argue that recent and ongoing massive star formation plays an important role in determining the colours of many LSB spirals. We briefly discuss these results in the context of the spectral evolution of spiral galaxies in general.
Travel-related schistosomiasis, strongyloidiasis, filariasis, and toxocariasis: the risk of infection and the diagnostic relevance of blood eosinophilia
Gijs G Baaten, Gerard J Sonder, Tom van Gool, Joan A Kint, Anneke van den Hoek
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-84
Abstract: Visitors of a pre-travel health advice centre donated blood samples for serology and blood cell count before and after travel. Samples were tested for eosinophilia, and for antibodies against schistosomiasis, strongyloidiasis, filariasis, and toxocariasis. Previous infection was defined as seropositivity in pre- and post-travel samples. Recent infection was defined as a seroconversion. Symptoms of parasitic disease were recorded in a structured diary.Previous infection was found in 112 of 1207 subjects: schistosomiasis in 2.7%, strongyloidiasis in 2.4%, filariasis in 3.4%, and toxocariasis in 1.8%. Recent schistosomiasis was found in 0.51% of susceptible subjects at risk, strongyloidiasis in 0.25%, filariasis in 0.09%, and toxocariasis in 0.08%. The incidence rate per 1000 person-months was 6.4, 3.2, 1.1, and 1.1, respectively. Recent infections were largely contracted in Asia. The positive predictive value of eosinophilia for diagnosis was 15% for previous infection and 0% for recent infection. None of the symptoms studied had any positive predictive value.The chance of infection with schistosomiasis, strongyloidiasis, filariasis, and toxocariasis during one short-term journey to an endemic area is low. However, previous stay leads to a cumulative risk of infection. Testing for eosinophilia appeared to be of no value in routine screening of asymptomatic travelers for the four helminthic infections. Findings need to be replicated in larger prospective studies.Helminth infections are a major health problem in the developing world. Due to increased travel to developing countries and changes in travel behavior, they have gained importance in the developed world, particularly among travelers [1].Untreated helminth infection may result in long-term adverse outcomes. Because symptomatology can be absent or non-specific, blood eosinophil count is commonly used as a screening tool [2-4]. Schistosomiasis, strongyloidiasis, filariasis, and toxocariasis are four common helmint
The Middle Miocene insectivores from Sámsonháza 3 (Hungary, Nógrád County): Biostratigraphical and palaeoenvironmental notes near to the Middle Miocene Cooling
Prieto J,Hoek Ostende L W van den,Hír J
Bulletin of Geosciences , 2012, DOI: 10.3140/bull.geosci.1296
Abstract: Large and well preserved micro-mammal faunas are available from the Middle Miocene from Hungary, but very little attention was paid on insectivores, although this group provides good palaeoenvironmental and palaeogeographical indication. As a first step we review the material from Sámsonháza 3 (Hungary, Nógrád County), based on both published and new fossils. We report the dimylid Plesiodimylus sp., the soricid cf. Paenelimnoecus sp. and an indeterminate shrew. The erinaceids Parasorex sp. and Lantanotherium sp., and the talpid Desmanodon sp. are described for the first time from Hungarian deposits. The fauna indicates a relatively wet environment and is in agreement with the Middle Badenian correlation proposed on the basis of the rich molluscan fauna of the locality.
Evaluation of Hepatitis A Vaccine in Post-Exposure Prophylaxis, The Netherlands, 2004-2012
Jane Whelan, Gerard J. Sonder, Lian Bovée, Arjen Speksnijder, Anneke van den Hoek
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078914
Abstract: Background The secondary attack rate of hepatitis A virus (HAV) among contacts of cases is up to 50%. Historically, contacts were offered immunoglobulin (IG, a human derived blood product) as post-exposure prophylaxis (PEP). Amid safety concerns about IG, HAV vaccine is increasingly recommended instead. Public health authorities’ recommendations differ, particularly for healthy contacts ≥40 years old, where vaccine efficacy data is limited. We evaluated routine use of HAV vaccine as an alternative to immunoglobulin in PEP, in those considered at low risk of severe infection in the Netherlands. Methods Household contacts of acute HAV cases notified in Amsterdam (2004-2012) were invited ≤14 days post-exposure, for baseline anti-HAV testing and PEP according to national guidelines: immunoglobulin if at risk of severe infection, or hepatitis A vaccine if healthy and at low risk (aged <30, or, 30-50 years and vaccinated <8 days post-exposure). Incidence of laboratory confirmed secondary infection in susceptible contacts was assessed 4-8 weeks post-exposure. In a vaccinated subgroup, relative risk (RR) of secondary infection with estimated using Poisson regression. Results Of 547 contacts identified, 191 were susceptible to HAV. Per-protocol, 167 (87%) were vaccinated (mean:6.7 days post-exposure, standard deviation(sd)=3.3) and 24 (13%) were given immunoglobulin (mean:9.7 days post-exposure, sd=2.8). At follow-up testing, 8/112 (7%) had a laboratory confirmed infection of whom 7 were symptomatic. All secondary infections occurred?in vaccinated contacts,?and half were >40 years of age. In healthy contacts vaccinated per-protocol ≤8 days post-exposure, RRref. ≤15 years of secondary infection in those >40 years was 12.0 (95%CI:1.3-106.7). Conclusions Timely administration of HAV vaccine in PEP was feasible and the secondary attack rate was low in those <40 years. Internationally, upper age-limits for post-exposure vaccination vary. Pending larger studies, immunoglobulin should be considered PEP of choice in people >40 years of age and those vulnerable to severe disease.
Adherence to Chemoprophylaxis and Plasmodium falciparum Anti-Circumsporozoite Seroconversion in a Prospective Cohort Study of Dutch Short-Term Travelers
Sanne-Meike Belderok, Anneke van den Hoek, Will Roeffen, Robert Sauerwein, Gerard J. B. Sonder
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0056863
Abstract: Background We conducted a prospective study in a cohort of short-term travelers assessing the incidence rate of anti-circumsporozoite seroconversion, adherence to chemoprophylaxis, symptoms of malaria during travel, and malaria treatment abroad. Methods Adults were recruited from the travel clinic of the Public Health Service Amsterdam. They kept a structured daily travel diary and donated blood samples before and after travel. Blood samples were serologically tested for the presence of Plasmodium falciparum anti-circumsporozoite antibodies. Results Overall, the incidence rate (IR) of anti-circumsporozoite seroconversion was 0.8 per 100 person-months. Of 945 travelers, 620 (66%) visited high-endemic areas and were advised about both chemoprophylaxis and preventive measures against mosquito bites. Most subjects (520/620 = 84%) took at least 75% of recommended prophylaxis during travel. Travel to Africa, use of mefloquine, travel duration of 14–29 days in endemic areas, and concurrent use of DEET (N,N-diethyl-meta-toluamide) were associated with good adherence practices. Four travelers without fever seroconverted, becoming anti-circumsporozoite antibody-positive. All four had been adherent to chemoprophylaxis; two visited Africa, one Suriname, one India. Ten subjects with fever were tested for malaria while abroad and of these, three received treatment. All three were adherent to chemoprophylaxis and tested negative for anti-circumsporozoite antibodies. Conclusion Travel to Africa, using mefloquine, travel duration of 14–29 days in endemic areas, and use of DEET were associated with good adherence to chemoprophylaxis. The combination of chemoprophylaxis and other preventive measures were sufficient to protect seroconverting travelers from clinical malaria. Travelers who were treated for malaria abroad did not seroconvert.
Seroprevalence of varicella-zoster virus and predictors for seronegativity in the Amsterdam adult population
Gini GC van Rijckevorsel, Marjolein Damen, Gerard J Sonder, Maarten F Schim van der Loeff, Anneke van den Hoek
BMC Infectious Diseases , 2012, DOI: 10.1186/1471-2334-12-140
Abstract: The study was a cross-sectional survey of the Amsterdam population (2004), and the study sample was stratified by age and ethnicity, with deliberate oversampling of minority ethnic groups. Serum samples obtained from 1,341 residents in 2004 were tested for antibodies to VZV. Basic demographic data (gender, age, country of birth, age at immigration and number of children) were also available.The anti-VZV seroprevalence in the overall Amsterdam population was estimated to be 94% (95% confidence intervals; 92–96%). Regarding ethnic origin, first generation immigrants (Moroccan immigrants 90%, Surinamese or Antillean immigrants 91%, and Turkish 92%), especially those that migrated after the age of 11?years, were more likely to be anti-VZV seronegative compared to those arriving at an earlier age or those born in the Netherlands (97–98%). Both ethnic origin and generation of immigration were positive predictors for IgG seronegativity to VZV (p<0.015). No other predictors for seronegativity were found.The results of this study imply that about 4–8% of the general adult Amsterdam population is still susceptible to infection with VZV, and that susceptibility is even higher in some immigrant groups. When assessing the risk of infection after VZV exposure alertness is needed for vulnerable persons like pregnant women, patients with hematological malignancies or organ transplants in particular among first-generation immigrants.
Incidence, risk factors and treatment of diarrhoea among Dutch travellers: reasons not to routinely prescribe antibiotics
Sanne-Meike Belderok, Anneke van den Hoek, Joan A Kint, Maarten F Schim van der Loeff, Gerard JB Sonder
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-295
Abstract: Persons who attended the travel clinic of the Public Health Service Amsterdam in 2006-2007 before short-term travel to tropical and subtropical countries were invited to answer a questionnaire regarding sociodemographics and travel purpose; they were also asked to keep a daily structured travel diary, recording their itinerary, symptoms, and self-medication or consultation with a doctor. Diarrhoea episodes containing blood or mucous were considered severe.Of 1202 travellers, the median age was 38 years, and the median travel duration 3 weeks. Of all episodes, 96% were mild. The median duration of TD was 2 days and significantly shorter in subsequent episodes compared to first episodes (p < 0.0005). Of first episodes 38% started in the first travel week. The incidence rate (IR) for first episodes was 2.49 (95% confidence interval [CI], 2.30-2.70) per 100 travel days, with the highest IR among travellers to South-Central and West Asia. The IR for first and subsequent episodes was comparable. Risk factors for first episodes included female sex, a Western country of birth, and tourism as the purpose of travel. The lowest risk was in travellers to South America. An independent risk factor for subsequent episodes was female sex. In total, 5% of travellers used antibiotics; of those, 92% had mild diarrhoea, and 53% received antibiotics over the counter.TD is common among travellers, but the overall course is mild, not requiring treatment. The incidence rates for first and second episodes are comparable. Female sex is a risk factor for the first episode, as well as subsequent ones. Prescription antibiotics are not needed in short-term healthy travellers.International tourism in 2007 showed approximately 908 million tourist arrivals worldwide [1]. Among tourists from industrialized countries, about 80 million crossed the borders of tropical and subtropical countries, many of which are developing areas, each year [2]. The most common infectious health problem among travellers
Page 1 /33940
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.