Effervescence assisted dispersive liquid–liquid microextraction followed by microvolume UV-Vis spectrophotometric determination of surfactants in water

The novel and simple methods for the sensitive determination of cationic and anionic surfactants in water based on effervescence assisted dispersive liquid–liquid microextraction and microvolume UV-Vis spectrophotometry have been developed. The method involves ion-pair extraction of cationic and anionic surfactants with organic dyes (methyl orange and azure A, respectively) during the dispersion of extraction solvent (CHCl₃) by CO₂ bubbles which are formed by the injection of a mixture of the extraction solvent and proton donor solvent into the sample solution which contains carbonate-ions as effervescency agent. The analytical performance of the proposed procedure was compared with the conventional dispersive liquid–liquid microextraction. Appropriate experimental conditions for both methods were investigated. The absorbances of the colored extracts at wavelengths of 440 and 625 nm obey Beer's law within the range of 0.1–5.0 mg/L for both cationic and anionic surfactants. The limit of detection (LOD) obtained using the effervescence assisted extraction method was 30 µg/L for cationic and anionic surfactants. The proposed methods were successfully applied to determination of surfactants in water samples.     

Ecosystem services in infrastructure planning – a case study of the projected deepening of the Lower Weser river in Germany

We consider how ecosystem services can be incorporated into water infrastructure planning by studying the projected deepening of the Lower Weser river channel in Germany. We recalculate the project's benefit–cost ratio by integrating the monetary value of changes in different ecosystem services, as follows: (1) the restoration costs of a mitigation measure for a loss in fresh water supply for agricultural production in the estuary region, (2) the costs of a loss in habitat services, transferring the willingness to pay from a contingent valuation study to the area assessed in the environmental impact assessment, and (3) the benefits of emissions savings induced by more efficient shipping, taking a marginal abatement cost approach. We find that including monetary values for ecosystem service changes leads to a substantial drop in the benefit–cost ratio. On this basis, we argue for a reform of the standard cost–benefit analysis to facilitate more complete welfare assessments.     

Are all experiments created equal? A framework for analysis of the learning potential of policy experiments in environmental governance

Environmental changes are increasing the need to understand complex cross-scale feedbacks in social–ecological systems. However, consistent conceptualisation of learning associated with environmental governance is lacking, and research mainly centres on individual variables. This paper identifies a typology of such learning, and theorises about configurations of variables. Focusing on experimentation as an intervention geared towards learning, it proposes a definition of policy experiment. A theoretical framework is presented, summarising a typology of experiments based on learning-related variables embedded in design choices, and reflected in institutional rule aggregations. The framework facilitates systematic analysis of real-world cases and testing of hypotheses on the effects of different types of experiment on learning. A case study demonstrates application of the framework. Results suggest future research paths that include attention to additional relevant variables. The findings have relevance for scholars interested in experimentation and learning, and environmental policy-makers considering experimentation to assess policy innovations.     

Science–policy interactions in Austrian,Dutch, and Swiss climate policy: a comparative account

Scientific expertise plays an important role in the complex field of climate policy. Consequently, science–policy interactions have been institutionalized in many countries. However, science–policy arenas vary considerably across countries. Scholars mainly attribute these differences to the influence of specific political cultures. The literature has primarily compared science–policy arenas of countries with diverging political cultures, whereas comparisons of countries with similar political cultures are rare. The latter is especially true for neo-corporatist cultures. Against this background, we compare the climate science–policy arenas of three neo-corporatist countries, Austria, the Netherlands, and Switzerland. Conceptually, we draw on the literature regarding politico-cultural imprints in science–policy arenas. We operationalize national science–policy arenas along four dimensions: the knowledge actors, the organizational formats, the styles of science–policy interactions, and their transparency and visibility. Overall, the three arenas reveal many similarities and much fewer differences. Most similarities correspond to neo-corporatist patterns. However, some similarities consistently deviate from neo-corporatist patterns. Interestingly, almost all differences between the countries match national variations of neo-corporatism. In light of these observations and the specific problem structure of climate policy, we develop research questions to investigate potential explanations for correspondence to and deviation from neo-corporatist patterns.     

Prenatal diagnosis of Schwartz–Jampel syndrome with early manifestation

A mother who had given birth to a child with Schwartz–Jampel syndrome (SJS) with neonatal manifestations (myotonia, congenital contractures, bowing of femora and tibiae) underwent ultrasonic fetal examination during the 17th and 19th week of her second pregnancy. Moderately decreased fetal motor activity and constant flexion of the fingers were observed at both examinations. In addition, there was mild bowing and shortening of the femora. At birth, the child presented with the characteristic pattern of SJS similar to her older brother. Prenatal ultrasonic diagnosis of Schwartz–Jampel syndrome is possible, at least for the form with neonatal onset of myotonia and contractures.     

Germline mosaicism complicates molecular diagnosis of Lesch–Nyhan syndrome

A healthy female with a brother suffering from Lesch–Nyhan syndrome was assigned a carrier status on the basis of haplotype analysis employing flanking and intragenic polymorphic markers of the HPRT gene. Her mother has been confirmed as a definite carrier by cell growth selection studies in cultured fibroblasts. In our proposita's first pregnancy, a male fetus was identified carrying the risk allele. Afterwards, the underlying novel mutation A161E (GCA→GAA at position c482) could be identified in the affected brother and in the heterozygous mother but not in the DNA of the pregnant sister and fetus. The fetus was also confirmed to be normal by uptake of 14C-hypoxanthine in cultured amniotic cells. To test the discrepancy, the investigation was extended by recruiting additional family members. The data obtained showed that the mother had passed her risk haplotype to the affected son as well as to her mutation-carrying and non–mutation-carrying daughters. This provides the first evidence of concomitant somatic and germline mosaicism in Lesch–Nyhan syndrome. The study has a bearing on genetic counselling and cautions against the reliability of only using indirect genetic diagnosis even with intragenic markers. Copyright © 2004 John Wiley & Sons, Ltd.     

Prenatal diagnosis of Niemann–Pick diseases types A,B and C

Prenatal diagnosis of Niemann–Pick disease types A and B is routinely accomplished by sphingomyelinase assay. For Niemann–Pick type C disease, demonstration of an abnormal intracellular cholesterol trafficking is a complex procedure, and mutational analysis (NPC1 or NPC2/HE1 gene), whenever feasible, represents a major advance. Copyright © 2002 John Wiley & Sons, Ltd.     

Tetrasomy 12p—unusual presentation in CVS

CVS direct preparations usually achieve limited resolution and are better at detecting numerical rather than structural abnormalities. A CVS direct preparation analyzed using G-banding revealed a 47,XY,+G karyotype in 5 of 11 cells and was reported as mosaic for trisomy 21. Subsequent analysis of the CVS culture found only normal male cells. Amniocentesis revealed both normal male cells and cells with an extra F-group chromosome. Fluorescence in situ hybridization (FISH) identified this chromosome to be an isochromosome from the short arm of chromosome 12 [i(12)(p10)]. The amniocyte karyotype was reported as 47,XY,+i(12)(p10)[12]/46,XY[8].ish i(12)(p10)(wcp12+), which is associated with Pallister–Killian syndrome. Reexamination of the CVS direct preparation by FISH with a chromosome 12 centromere probe confirmed the karyotype of this tissue to be 47,XY,+mar[5]/46,XY[6].nuc ish 12cen(D12Z3 × 3)/12cen(D12Z3 × 2). Thus, multiple studies, including amniocentesis and fluorescence in situ hybridization, may be required to fully and accurately evaluate abnormalities detected by CVS. This case also indicates that mosaicism for supernumerary isochromosomes may have a complex origin. Copyright © 2003 John Wiley & Sons, Ltd.     

The behaviour of ant transporters at the old and new nests during successive colony emigrations

Colonies of the ant Temnothorax albipennis improve their collective performance over successive emigrations (Langridge et al. Behav Ecol Sociobiol 56:523–529, 2004, Behav Ecol Sociobiol 62:447–456, 2008). Here, by analysing the performance of individual transporters (workers that carry the brood, queen and a proportion of adults), we investigate whether they spend less time at the old and new nests during repeated emigrations. Transporters expedited choosing and picking up brood items at the old nest and depositing them in the new nest. Such improvements were not associated with adult transport. Generally, when carrying brood items, but not when carrying adults, transporters visited several locations in the new nest before depositing them. Transporters did not interact with other adults when depositing brood items. Consequently, reductions in depositing times are the sum of time savings made by individual transporters. By contrast, transporters spent most time interacting with other adults before picking up brood items at the old nest. As the frequency of these interactions did not decline, we suggest the behaviours of interacting adults were modified in a way that hastened their completion. Thus, reductions in picking-up times probably occur because of time saved during interactions.