Generation of abstract programming interfaces from syntax definitions

Tree Manipulation; Using the ATerm-Library to represent tree-like data structures has become a popular activity, especially amongst developers of e.g. lexical scanners, parsers, rewrite engines and model checkers. Practical experience with the ATerm-Library in the ASF+SDF Meta-Environment has shown that the development and maintenance of tools that access ATerms using handcrafted code is involved and very error prone. Both the make and match paradigm and the direct manipulation of ATerms suffer from the fact that the programmer uses knowledge about the underlying structure (a.k.a. the signature) of the ATerm that represents the data type being accessed. Hard-wiring this knowledge in various tools makes it difficult to maintain the tools with respect to changes in the data structure. By lifting the data definition and its mapping to an ATerm representation away from the level of tool implementation, it becomes possible to generate a library of access functions on the data type, which can be used by all the tools that need access to it. The tools no longer directly manipulate the ATerm representation, but rather invoke methods described by the API of the library, thus abstracting from the fact that ATerms are used for the implementation of the data type. This paper describes how an API and its implementation can be generated from a syntax definition of the data type. In particular we describe how a grammar (in SDF) can be used to generate a library of access functions that manipulate the parse trees of terms over this syntax. Application of this technique in the ASF+SDF Meta-Environment has resulted in a spectacular elimination of 47 of the handwritten code, thus greatly improving both maintainability of the tools and their flexibility with respect to changes in the parse tree format

Changes in older adult loneliness: results from a seven-year longitudinal study

This study examines loneliness and its correlates-health, residential care, partner status, and network size-over a seven-year period among adults born between 1908 and 1937. The four waves of data are from the Dutch Living Arrangements and Social Networks of Older Adults" and the "Longitudinal Aging Study of Amsterdam programs. Data from at least two waves are available for 2,925 respondents. Results show that older adults generally become lonelier as time passes. The increase is greater for the oldest, the partnered, and those with a better functional capacity at baseline. Older adults who lose their partner by death show the greatest increase in loneliness. Not all older adults become more lonely: Improvement in functional capacity and network expansion lead to less loneliness. Entry into residential care does not affect loneliness. The longitudinal design provides new insights into factors that protect against loneliness compared to cross-sectional studies. © 2005 Sage Publications

Monitoring of Cystic Fibrosis Lung Disease Using Computed Tomography

For clinical management of cystic fibrosis (CF) lung disease to be effective, onset and worsening of lung abnormalities should be closely monitored. Pulmonary function tests (PFTs) are currently the gold standard to monitor CF lung disease. Lung structure can be more sensitively monitored using computed tomography (CT) rather than chest radiography. Firstly, we compared in two pediatric cohorts the sensitivities of CT and PFTs to detect onset and worsening of CF lung disease. We showed that five published CT scoring systems are comparable and have good intra- and interobserver agreement. Secondly, we showed that CT scoring systems and quantitative CT-measurements of airway wall thickening and bronchiectasis are more sensitive to detect the start and worsening of CF lung disease than are PFTs. Bronchiectasis-score worsened most in children and the worsening remained undetected by the PFTs and the quantitative measurements. Quantitative CT-measurements of air! way wall thickening worsened significantly, whereas PFTs and airway wall thickness measured by scoring remained unchanged. Thirdly, we developed a computational model to study radiation risks associated with CT scanning in CF. Risks from lifelong biennial CT scanning in CF were found to be acceptably low given the currently reduced life expectancy. Finally we provided normal CT-values of lung parenchyma and airway wall and lumen that can be used to study lung growth aberrations due to CF. Our data support routine CT scanning to monitor CF lung disease. In addition, bronchiectasis-score and quantitatively measured airway wall thickening may be useful surrogate endpoints for clinical trials in CF

New Ways of Theorizing and Conducting Research in the Field of Loneliness and Social Isolation

Loneliness is nowadays considered to be one of the main problems in society. The negative experience of a discrepancy between the desired and the achieved personal network of relationships is common and affects both younger and older adults. This chapter first addresses well-established aspects and new developments in the main concepts of loneliness and social isolation, the measuring instruments and the prevalence of loneliness. The chapter continues by an overview of theoretical ideas regarding loneliness, focusing on individuallevel and societal predisposing characteristics as well as on genetic/evolutionary perspectives on the onset and co

ARCHIPRIX : here we come!

Veel Wageningse afstudeerders leveren degelijke onderzoeksrapporten af; die voldoen echter niet, om voor de jaarlijkse prijs voor (landschaps)architectuur en stedebouw in aanmerking te komen. Dàt moeten ontwerpen zij

Athymic nude rat. III natural cell mediated cytotoxicity.

Homozygous rnu/rnu and heterozygous +/rnu rats were investigated and compared with each other for the existence of natural cell-mediated cytotoxicity. Investigated were total, adherent, and nonadherent cell populations from spleen, peritoneal cavity, and mesenteric lymph node. The natural killer (NK) cell activity was measured in a 4-hr 51Cr-release assay with a xenogeneic murine YAC lymphoma target cell line. In both and +/rnu rats the peritoneal cavity had the highest percentage of activity, while the spleen and mesenteric lymph node showed a lower activity. The mesenteric lymph node of +/rnu rats of 8–10 weeks of age was found to express a very low activity, in contrast to a very high activity in rats. For almost every effector to target cell (E:T) ratio investigated (100, 70, 50, and 10), the natural killer cell activity in the nude rats was found to be significantly higher than in their thymus-bearing littermates. In comparison with that of +/rnu rats, NK activity in the nonadherent cell fractions of athymic rats was 50 to 60% higher in spleen cells, doubled in peritoneal cells, and increased 10-fold or higher in lymph node cells. Investigations o

Progressive damage on high resolution computed tomography despite stable lung function in cystic fibrosis

For effective clinical management of cystic fibrosis (CF) lung disease it is important to closely monitor the start and progression of lung damage. The aim of this study was to investigate the ability of high-resolution computed tomography (HRCT) scoring systems and pulmonary function tests (PFT) to detect changes in lung disease. CF children (n=48) had two H