The accuracy of population density estimates of copepods and cladocerans, using data from Tjeukemeer (the Netherlands) as an example

Hydrobiologia ◽  
1985 ◽  
Vol 124 (1) ◽  
pp. 3-11 ◽  
Author(s):  
H. W. de Nie ◽  
J. Vijverberg
Keyword(s):  
Population Density ◽  
The Netherlands ◽  
Density Estimates ◽  
Using Data

scholarly journals E-bike user groups and substitution effects: evidence from longitudinal travel data in the Netherlands

2021 ◽  
Author(s):  
Mathijs de Haas ◽  
Maarten Kroesen ◽  
Caspar Chorus ◽  
Sascha Hoogendoorn-Lanser ◽  
Serge Hoogendoorn
Keyword(s):  
The Netherlands ◽  
Longitudinal Data ◽  
Latent Class ◽  
Good Alternative ◽  
Substitution Effects ◽  
Or Education ◽  
Cross Sectional ◽  
User Groups ◽  
Using Data ◽  
Mode Of Transport

AbstractIn recent years, the e-bike has become increasingly popular in many European countries. With higher speeds and less effort needed, the e-bike is a promising mode of transport to many, and it is considered a good alternative for certain car trips by policy-makers and planners. A major limitation of many studies that investigate such substitution effects of the e-bike, is their reliance on cross-sectional data which do not allow an assessment of within-person travel mode changes. As a consequence, there is currently no consensus about the e-bike’s potential to replace car trips. Furthermore, there has been little research focusing on heterogeneity among e-bike users. In this respect, it is likely that different groups exist that use the e-bike for different reasons (e.g. leisure vs commute travel), something which will also influence possible substitution patterns. This paper contributes to the literature in two ways: (1) it presents a statistical analysis to assess the extent to which e-bike trips are substituting trips by other travel modes based on longitudinal data; (2) it reveals different user groups among the e-bike population. A Random Intercept Cross-Lagged Panel Model is estimated using five waves of data from the Netherlands Mobility Panel. Furthermore, a Latent Class Analysis is performed using data from the Dutch national travel survey. Results show that, when using longitudinal data, the substitution effects between e-bike and the competing travel modes of car and public transport are not as significant as reported in earlier research. In general, e-bike trips only significantly reduce conventional bicycle trips in the Netherlands, which can be regarded an unwanted effect from a policy-viewpoint. For commuting, the e-bike also substitutes car trips. Furthermore, results show that there are five different user groups with their own distinct behaviour patterns and socio-demographic characteristics. They also show that groups that use the e-bike primarily for commuting or education are growing at a much higher rate than groups that mainly use the e-bike for leisure and shopping purposes.

Population Densities Allowed Around Dutch SEVESO Establishments

2000 ◽  
Author(s):  
G. M. H. Laheij ◽  
B. J. M. Ale ◽  
J. G. Post
Keyword(s):  
Population Density ◽  
The Netherlands ◽  
Individual Risk ◽  
Population Densities ◽  
Planning Policy ◽  
Relative Contribution ◽  
Societal Risk ◽  
Dangerous Substances ◽  
The Individual ◽  
Uniform Population

Abstract In the Netherlands, the individual risk and societal risk are used in efforts to reduce the number of people exposed to the effect of an accident at an establishment with dangerous substances. To facilitate the societal risk planning policy an investigation was carried out for the Dutch SEVESO establishments to investigate the possibility of determining a generic uniform population density for the zone between the individual risk contours of 10−5 and 10−6 per year. The indicative limit for the societal risk at this density was not to be exceeded. Also there was to be enough space left for a significantly higher population density outside the individual risk contour of 10−6 per year. The RORISC methodology and the actual data for the 124 Dutch SEVESO establishments were used to determine the generic uniform population density. Based on the data available it can be concluded that the maximum allowed uniform population density in the zone between the individual risk contours of 10−5 and 10−6 per year is lower than one person per hectare. At this density there is no space left for a higher population density outside the individual risk contour of 10−6 per year. For uniform population densities the relative contribution to the societal risk has been found significant up to the individual risk contour of 10−7 per year.

Density and activity patterns of ocelot populations in Yasuní National Park, Ecuador

Mammalia ◽  
2016 ◽  
Vol 80 (4) ◽  
Author(s):  
Julia Salvador ◽  
Santiago Espinosa
Keyword(s):  
Population Density ◽  
Habitat Loss ◽  
National Park ◽  
Conservation Status ◽  
Activity Patterns ◽  
Camera Trap ◽  
Oil Extraction ◽  
Density Estimates ◽  
Yasuni National Park ◽  
Ecuadorian Amazon

AbstractOcelots were historically hunted for their skins but habitat loss is now their most serious threat, causing rapid declines in populations throughout their range. Ocelot abundance has been estimated for various locations across the Neotropics, but we still lack this information from some countries, including Ecuador. Knowing whether ocelot abundance is increasing or decreasing is important to assess the conservation status of this species and the conditions of its habitats in the Ecuadorian Amazon and in the region. To determine whether ocelot abundance and its behavior are affected by human-related activities, camera-trap surveys were carried out in two localities of Yasuní National Park (YNP), one that has experienced hunting, oil extraction, and roads (Maxus Road) and one that is largely unaffected by these activities (Lorocachi). During the survey, 35 and 36 individual ocelots were photographed in Maxus Road and Lorocachi, respectively. Population density estimates were similar for both localities, ranging from 0.31 (SE±6) to 0.85 (SE±17) ocelots/km

scholarly journals Gypsy–Traveller communities in the United Kingdom and the Netherlands: socially and digitally excluded?

2018 ◽  
Vol 42 (5) ◽  
pp. 637-653
Author(s):  
Leanne Townsend ◽  
Koen Salemink ◽  
Claire Denise Wallace
Keyword(s):  
United Kingdom ◽  
The Netherlands ◽  
Digital Communications ◽  
Digital Inclusion ◽  
Left Behind ◽  
The United Kingdom ◽  
Mainstream Society ◽  
Using Data ◽  
Socially Excluded ◽  
The Impact

With the pervasiveness of digitisation communications, those that are left behind are seen as socially excluded. In both academic and policy discourses, it is assumed that digital inclusion as a route into mainstream society is a desirable solution to problems of multiple exclusion and has led to many studies of the digital inclusion/exclusion of ‘hard to reach’ groups. Yet, Gypsy–Travellers, among the most marginalised people in society, have received little attention. Using data from the Netherlands and the United Kingdom, we assess the impact of digital communications on Gypsy–Traveller communities. This article makes a contribution in the following ways: First, we address the theories of ‘fields of inclusion’ to show how exclusion and inclusion work together in different ways; Second, we explore how different policy frameworks in the Netherlands and the United Kingdom shape these possibilities; Third, we document the forms of inclusion that Gypsy–Travellers experience in terms of digital communications; Fourth, we look at how Gypsy–Travellers use digital communications to recreate their own cultures as well as selectively integrate with mainstream society.

Merits and caveats of propensity scores to adjust for confounding

2018 ◽  
Vol 34 (10) ◽  
pp. 1629-1635 ◽  
Author(s):  
Edouard L Fu ◽  
Rolf H H Groenwold ◽  
Carmine Zoccali ◽  
Kitty J Jager ◽  
Merel van Diepen ◽  
...  
Keyword(s):  
Risk Factors ◽  
The Netherlands ◽  
Health Outcomes ◽  
Observational Data ◽  
Propensity Scores ◽  
Cooperative Study ◽  
Dialysis Patients ◽  
Proper Understanding ◽  
The Past ◽  
Using Data

Abstract Proper adjustment for confounding is essential when estimating the effects of treatments or risk factors on health outcomes in observational data. To this end, various statistical methods have been developed. In the past couple of years, the use of propensity scores (PSs) to control for confounding has increased. Proper understanding of this method is necessary to critically appraise research in which it is applied. In this article, we provide an overview of PS methods, explaining their concept, advantages and possible disadvantages. Furthermore, the use of PS matching, PS adjustment and PS weighting is illustrated using data from the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) cohort of dialysis patients.

Bayesian Estimation of Normal Ogive Item Response Curves Using Gibbs Sampling

1992 ◽  
Vol 17 (3) ◽  
pp. 251-269 ◽  
Author(s):  
James H. Albert
Keyword(s):  
Gibbs Sampling ◽  
Maximum Likelihood Estimates ◽  
Posterior Density ◽  
Response Curves ◽  
Density Estimates ◽  
Mathematics Placement ◽  
Item Parameters ◽  
Normal Ogive Model ◽  
Using Data ◽  
Placement Exam

The problem of estimating item parameters from a two-parameter normal ogive model is considered. Gibbs sampling (Gelfand & Smith, 1990) is used to simulate draws from the joint posterior distribution of the ability and item parameters. This method gives marginal posterior density estimates for any parameter of interest; these density estimates can be used to judge the accuracy of normal approximations based on maximum likelihood estimates. This simulation technique is illustrated using data from a mathematics placement exam.

scholarly journals Mode of Conception of Twin Pregnancies: Willingness to Reply to Survey Items and Comparison of Survey Data to Hospital Records

2008 ◽  
Vol 11 (3) ◽  
pp. 349-351 ◽  
Author(s):  
C. E. M. Toos van Beijsterveldt ◽  
Chantal Hoekstra ◽  
Roel Schats ◽  
Grant W. Montgomery ◽  
Gonneke Willemsen ◽  
...  
Keyword(s):  
Data Collection ◽  
The Netherlands ◽  
Survey Data ◽  
Survey Study ◽  
Hospital Records ◽  
Assisted Reproduction Techniques ◽  
Twin Registry ◽  
Using Data ◽  
Large Survey ◽  
Twin Pregnancies

AbstractBased on results from a survey study in a sample of Australian parents of twins, Raj and Morley (2007) reported that questions concerning the mode of conception of twins may be offensive to parents. We looked at the willingness to reply to questions about mode of conception of twin pregnancies in a large survey study that was completed by 20,150 mothers of twins from the Netherlands Twin Registry. Data collection took place in 2005/2006. The amount of missing data was examined and by using data from earlier survey studies, responders and nonresponders were compared with respect to their answers to questions on assisted reproduction techniques. In addition, we assessed the reliability of the question on mode of conception by comparing the survey data with hospital records in a subsample of 80 mothers of twins. We found no indication that mothers of twins were not prepared to reply to questions on mode of conception. Only a small number of mothers did not fill in the question on mode of conception (0.8%). Also, the use of artificial fertility techniques did not differ between mothers who returned and mothers who did not return the 2005/2006 survey. The comparison of the survey data with the hospital records showed that mothers can accurately report on the mode of conception of their twins.

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