Prenatal diagnosis of free sialic acid storage disorders (SASD)

Free sialic acid storage disorders, Salla disease (SD) and Infantile sialic acid storage disease (ISSD), are lysosomal storage diseases due to impaired function of a sialic acid transporter, sialin, at the lysosomal membrane. Several mutations of the sialin gene, SLC17A5, are known, leading either to the severe neonatal/infantile disease or to the milder, adult-type developmental disorder, Salla disease. Free sialic acid accumulation in lysosomes causes increased tissue concentration and consequently elevated urinary excretion. Prenatal diagnosis of SASD is possible either by determination of free sialic acid concentration or by mutation analysis of the SLC17A5 gene in fetal specimen, in chorionic villus biopsy particularly. Both techniques have been successfully applied in several cases, sialic acid assay more often in ISSD cases but mutation analysis preferentially in SD. Sialic acid assay of amniotic fluid supernatant or cultured amniotic fluid cells may give erroneous results and should not be used for prenatal diagnosis of these disorders. The present comments are mainly based on our experience of prenatal diagnosis of SD in Finnish families. A founder mutation in SLC17A5 gene, 115C-> T, represents 95% of the disease alleles in the Finnish SD patients, which provides a unique possibility to apply mutation analysis. Therefore, molecular studies have successfully been used in 17 families since the identification of the gene and the characterization of the SD mutations. Earlier, eight prenatal studies were performed by measuring the free sialic acid concentration in chorionic villus samples. Copyright © 2006 John Wiley & Sons, Ltd.     

How does climate change adaptation affect public budgets? Development of an assessment framework and a demonstration for Austria

Mitigation and Adaptation Strategies for Global Change - Public adaptation to climate change affects government budgets directly on the expenditure side, but also indirectly via changes in the tax...     

An isobole-based statistical model and test for synergism/antagonism in binary mixture toxicity experiments

Synergism and antagonism are often defined in relation to the model of Concentration Addition (CA). Hence, it is vital for the conclusion of mixture toxicity studies to be able to test whether an observed deviation from CA reflects a true deviation or whether it is simply due to random variation. In this paper we consider a non-linear regression model for the classical ray designs for binary mixture experiments. The model combines dose–response curves for each mixture in the experiment with an isobole model, describing possible deviations from CA. The method allows us to test whether the chosen isobole model is reasonable for the data and to test the hypothesis of CA. Furthermore, it provides us with a measure of the degree of synergism/antagonism. The method is flexible since both the dose–response relationships and the isobole model can be chosen arbitrarily. We demonstrate the use of the method on datasets where combinations of pesticides are tested on a floating plant, Lemna minor, and an algae, Pseudokirchneriella subcapitata. Furthermore, we conduct a simulation study in order to explore the power with which a specific deviation from CA can be distinguished in different test-systems.     

Group foraging, patch exploitation time and the finder's advantage

 We use a combination of the marginal value theorem (MVT) of Charnov (1976), and a group foraging model featuring information sharing to address patch residence in an environment where food occurs in discrete patches. We shall show that among equal competitors the optimal patch time for the individual that finds the food patch is shorter than that for the non-finder among equal competitors, T _E < T _N. This is the case if the patch-finder commences food harvesting in the patch earlier and manages to monopolise a fraction of the prey items (finder's advantage) before the other individuals come to take their benefit. When individuals differ in their food-searching abilities so that some of them (producers) contribute proportionally more to food-searching than others (scroungers), and differ in ability to compete for the food found, a difference emerges between producer and scrounger individuals in the optimal patch time. Within a patch we always have the finder's advantage (T _E < T _N) regardless of phenotype. Between patches a suite of optimal patch times for encountering individuals emerges depending on the performance of producers and scroungers when changing from solitary feeding to feeding in a group. The optimal patch time for individuals that are affected more severely by competition is shorter than that for individuals of the phenotype with better competitive ability. When both phenotypes are affected similarly no difference in optimal patch times emerges. Received: 13 February 1996 / Accepted after revision: 28 September 1996     

A comparative study of prenatal ultrasound findings and post-mortem examination in a tertiary referral centre

This retrospective study compares the findings of prenatal ultrasound, performed in a tertiary fetal medicine centre, with the results of post-mortem examination in pregnancies complicated by suspected fetal abnormality that results in fetal loss. The study was carried out over a year at a teaching hospital, Fetal Medicine Centre and Regional Centre for Perinatal Pathology. Results were directly compared and the level of agreement between the ultrasound and post-mortem findings described. These were classified as having complete agreement; major agreement or major disagreement. The group of cases with major agreement between findings was further divided into those with significant, or minor, additional findings at post-mortem examination. Over the 12-month period, 153 ultrasound cases were identified, of which 47 were also examined by autopsy and were thus suitable for comparison in this study (30.7%). Complete agreement between ultrasound and post-mortem findings was found in 22 cases (46.8%). In 24 cases (51.1%), major agreement between ultrasound and post-mortem findings was seen. Of these, 11 had minor additional findings at post-mortem examination and 13 were found to have significant additional findings at post-mortem (27.7%), adding to the eventual diagnosis. In 12.8% of cases, post-mortem examination provided a definitive diagnosis. Only in one case was there complete discordance in the findings of the ultrasound examination and the autopsy (2.1%). No major disagreement between ultrasound and post-mortem findings was seen in 98% of cases. This study confirms the accuracy of prenatal ultrasound diagnosis in specialist centres, whilst emphasising the continuing importance of post-mortem examination in cases of fetal malformation to refine and, in some cases, define the diagnosis. Copyright © 2004 John Wiley & Sons, Ltd.     

The practice of participatory research and gender analysis in natural resource management

Stakeholder participation is expected to improve the efficiency, equity, and sustainability of natural resource management research and development (R&D) projects by ensuring that research reflects users’ priorities, needs, capabilities, and constraints. Use of participatory methods and tools is growing rapidly; however, there is little systematic evidence about what participation actually means in practice, or about what difference it makes. Based on an inventory of 59 self‐described participatory R&D projects in the area of natural resource management, this article characterizes the typical project and analyzes how stakeholders are selected, how they participate in the research process, and what their involvement means for project costs and impacts. The results suggest that, while projects are generating a range of direct and indirect benefits for participants, more careful attention needs to be paid to achieving equitable impacts. Current practices may lag behind best practices in key areas, such as power sharing and participant selection, and may therefore be missing important contributions from women and other marginalized groups.     

Relationships among employees' work and nonwork responses

This study was concerned with an examination of the relationships among employee responses to the work setting. Responses in the work and nonwork spheres were examined, and an attempt made to determine the stability of the relationships across organizations. Data were obtained from 651 employees of five midwestern organizations using four data sources—structured interviews, on-the-job observations, supervisory ratings, and personnel records. The analysis indicated that, in general, employee reactions in the work and nonwork spheres loaded on separate factors, and that the relationships among employee responses were relatively stable across organizations. Some directions for future research on this issue are suggested.