Turbulent dispersion in cloud-topped boundary layers

Compared to dry boundary layers, dispersion in cloud-topped boundary layers has received less attention. In this LES based numerical study we investigate the dispersion of a passive tracer in the form of Lagrangian particles for four kinds of atmospheric boundary layers: 1) a dry convective boundary layer (for reference), 2) a "smoke" cloud boundary layer in which the turbulence is driven by radiative cooling, 3) a stratocumulus topped boundary layer and 4) a shallow cumulus topped boundary layer. We show that the dispersion characteristics of the smoke cloud boundary layer as well as the stratocumulus situation can be well understood by borrowing concepts from previous studies of dispersion in the dry convective boundary layer. A general result is that the presence of clouds enhances mixing and dispersion ¿ a notion that is not always reflected well in traditional parameterization models, in which clouds usually suppress dispersion by diminishing solar irradiance. The dispersion characteristics of a cumulus cloud layer turn out to be markedly different from the other three cases and the results can not be explained by only considering the well-known top-hat velocity distribution. To understand the surprising characteristics in the shallow cumulus layer, this case has been examined in more detail by 1) determining the velocity distribution conditioned on the distance to the nearest cloud and 2) accounting for the wavelike behaviour associated with the stratified dry environmen

Readability of the web: a study on 1 billion web pages

We have performed a readability study on more than 1 billion web pages. The Automated Readability Index was used to determine the average grade level required to easily comprehend a website. Some of the results are that a 16-year-old can easily understand 50% of the web and an 18-year old can easily understand 77% of the web. This information can be used in a search engine to lter websites that are likely to be incomprehensible for younger users

Diagnostic accuracy of office blood pressure compared to home blood pressure in patients with mild cognitive impairment and dementia

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Management of preterm labor: atosiban or nifedipine?

Preterm birth is strongly associated with neonatal death and long-term neurological morbidity. The purpose of tocolytic drug administration is to postpone threatening preterm delivery for 48 hours to allow maximal effect of antenatal corticosteroids and maternal transportation to a center with specialized neonatal care facilities. There is uncertainty about the value of atosiban (oxytocin receptor antagonist) and nifedipine (calcium channel blocker) as first-line tocolytic drugs in the management of preterm labor. For nifedipine, concerns have been raised about unproven safety, lack of placebo-controlled trials, and its off-label use. The tocolytic efficacy of atosiban has also been questioned because of a lack of reduction in neonatal morbidity. This review discusses the available evidence, the pros and cons of either drug and aims to provide information to support a balanced choice of first-line tocolytic drug: atosiban or nifedipine

A social identity analysis of dissident Irish republicanism in Northern Ireland

Although Northern Ireland has become a more peaceful place since the Good Friday Agreement, spoiler groups in the form of dissident republicans remain persistent in their opposition. This thesis analyses the role of social identity as a vehicle for understanding dissident Irish republicanism in Northern Ireland. Social Identity is a theory for understanding social psychological phenomena relating to group structures and intergroup relations. By focussing on dissident republicanism, and its relation to the Republican mainstream as characterised by Sinn Féin, this thesis finds that the political and personal identity of dissident groups and their members is best understood as a reaction to the out-group. This study argues that the relative strength of the mainstream out-group in the wider republican communities has a positive impact in terms of supressing dissident republican violence, but arguably also a negative impact in terms of countering legitimate political opposition. This thesis proposes that the role of group structures and in/out-group divides are a prominent feature in understanding the occurrence and persistence of dissident republicanism. In doing so, it contributes to the existing literature, which tends to treat dissident and mainstream republicanism in an isolated manner, by unpacking the intertwined relationship between them. Through data gathered from an extensive period of fieldwork, that resulted in 29 interviews with different actors, this thesis provides a new and holistic understanding of dissident republicanism, not as a separate entity but as an inherently intertwined phenomenon in direct relation to the republican mainstream. Appreciating the origins and function of dissident groups is important in understanding their strategies and activities, and ultimately in determining possible solutions. It enhances understanding of some of the underlying difficulties in the Northern Irish peace process

Negative selectivity of Europe’s guest-worker immigration?

The aim of this paper is to empirically test the negative selectivity hypothesis as an explanation of the lower educational achievements of Turkish immigrant pupils. We do this by comparing educational achievement Turkish immigrant pupils in various European countries with the educational achievement of Turks at home, using the PISA 2006 data. Our analysis supports the thesis that the Turkish immigrants were negatively selected from their native population. The average score of Turkish immigrant pupils is substantially lower than the science score of comparable native pupils in Turkey. However, the result also show that the negative selectivity of Turkish immigrants can not by explained by the ‘guest-workers’ programs, because the largest negative science scores relative to the scores of the native pupils in the country of origin are found among the Italian first and second generation pupils, the Austrian first generation pupils, the French first generation immigrant pupils, and the German second generation pupils. A possible explanation is that all immigrants in Europe have more difficulties in establishing themselves and their children in comparison with immigrants in the traditional immigration countries, like the USA