In an earlier publication [2] we described a probe (oxytester) for the combined and remote measurement of temperature, conductivity and oxygen content of water. The present paper describes an improved instrument for the probe that is fully transistorized and powered by nickel-cadmium batteries which can be recharged with a built-in rectifier.<br/> Water temperature is measured with the aid of thermistors and directly indicated on a 3-digit counter (Helipot Digidial). The same applies for the <I>electrical resistance</I>. <I>Specific conductivity</I> can also be read directly from the instrument, because the circuits are precalibrated and resistance and capacity of the cable compensated. Amplification of the signal renders the instrument highly sensitive. Oxygen content of the water can be measured either by TÖDT's method (without auxiliary voltage) or polarometrically (with the same zinc and gold electrodes).<br/> The instrument has been designed for routine use in limnological research, and for industrial control of water conditions. It is being manufactured in Switzerland.

(1) The study deals with the electro-chemical measuring of oxygen contents in lakes and activated sludge basins according to the method of Tödt. The non recording short time test is used.<br/> (2) Exterior influences (conductivity, temperature, current, cathode surface) are discussed.<br/> (3) An oxygen sounder with good properties as regards mechanical strength and sensibility of the electrodes is described.<br/> (4) As further development, combined sounders called ‘Oxytester’ for measuring temperature and oxygen, respectively temperature, oxygen and conductivity were designed.<br/> (5) The disturbing influence of temperature on testing of oxygen is compensated electrically.<br/> (6) Tests with the oxytester in lake investigations reveal continuous profiles of oxygen, temperature and conductivity. In this way fine proportions of stratification can also be ascertained precisely.<br/> (7) The immediate diagrammatical representation of the tested values during the work on the lake gives precious indications for further testings.<br/> (8) Possibilities of measuring by sounders are illustrated by the test profiles from investigations made in some of the lakes in the Swiss Midland.

This paper presents a new electrochemical technique for DO measurements by means of membrane electrodes. In stead of the well-known steady state measurements, a transient technique which is more sensitive was used.<br/> This gives the possibility of measuring oxygen in the μg/l range. The system is independent of the membrane material and the membrane thickness. The stirring influence is considerably less than for steady state measurements. The independence of the membrane material will be especially useful for oxygen measurements in waste purification plants.

Sowohl in qualitativer (Kolibakterien) wie in quantitativer (totale Keimzahl) Hinsicht und zum erstenmal seit Beginn unserer Beobachtungen (1957–1959) nahm die bakteriologische Verunreinigung des “Petit-Lac” (Genfersee) nicht zu. Die gegenwärtige Situation entspricht dem “statu quo ante”.

Certain aspects of the problems connected with vertical migration were investigated by a new method. The experimental animals were adult males of the spring and summer populations of <I>Cyclops abyssorum praealpinus</I> (Kiefer) and <I>Cyclops vicinus lobosus</I> (Kiefer). The swimming traces were for the first time observed continually over a period of about eight minutes and photographically recorded, without exposing the animals to additional stimulus from the recording technique. The animals' natural biotope was imitated as closely as possible and experimentally stabilised so that irradiance reductions were the only stimulus. The results can be summarised under three headings:<br/> The direct result of an intensity reduction was a passive sinking of the animals, which we have called the "wait and see"-effect. It depends mainly on the relative reduction of intensity and, to a small extent, on the basic intensity.<br/> The later, more prolonged upward movement, which we call the "swimming-up"-effect, depends mainly on the prevailing irradiance.<br/> If the irradiance is constant, the animals swim for a considerable time in a restricted region, termed the "lingering-space". Its dimensions are determined by the direction-dependent swimming velocities. These velocities vary according to the species and the time of the year.<br/> As expected, the animals showed no horizontal orientation behaviour, nor were they influenced by the short-wavelength infra-red light used for photographing. An endogenous rhythm was only barely perceptible.<br/> These results were analysed exclusively by modern statistical techniques.

In two limno-corrals loaded with heavy metals the density of tubificid worms and chironomid larvae was higher than in the control. The better oxygen conditions observed in the heavy metal loaded corrals might explain this discrepancy. The higher oxygen concentration at the sediment-water interface was due to lower organic sedimentation, consequence of the primary production reduced by heavy metals. In all limno-corrals, the tubificid populations consisted of <I>Tubifex tubifex</I>. The size structure of tubificid populations in the heavy metal loaded corrals indicated a delayed reproduction compared to the control.

The mercury content of sieved, dried sediments from 24 sampling sites in the Horwer Bucht (Lake Lucerne) and its principal tributary stream system in Horw LU (Switzerland) was determined by flameless atomic absorption analysis. Mercury content significantly above background levels was found at several points. The distribution of mercury in the bay sediments implies that the Steinibach is the principal supplier of mercury to the bay.

A model of the carbon dioxide system in nature is derived and is used to further our understanding of the factors which control this system in the oceans, the atmosphere, and the sediments.

Volutin granules are intracellular storages of complexed inorganic polyphosphate (poly P). Histochemical staining procedures differentiate between pathogenic corynebacteria such as <em>Corynebacterum diphtheriae</em> (containing volutin) and non-pathogenic species, such as <em>C. glutamicum</em>. Here we report that strains ATCC13032 and MH20-22B of the non-pathogenic <em>C. glutamicum</em> also formed subcellular entities (18–37% of the total cell volume) that had the typical characteristics of volutin granules: (i) volutin staining, (ii) green UV fluorescence when stained with 4′,6-diamidino-2-phenylindole, (iii) electron-dense and rich in phosphorus when determined with transmission electron microscopy and X-ray microanalysis, and (iv) ³¹P NMR poly P resonances of isolated granules dissolved in EDTA. MgCl₂ addition to the growth medium stimulated granule formation but did not effect expression of genes involved in poly P metabolism. Granular volutin fractions from lysed cells contained polyphosphate glucokinase as detected by SDS–PAGE/MALDI-TOF, indicating that this poly P metabolizing enzyme is present also in intact poly P granules. The results suggest that formation of volutin is a more widespread phenomenon than generally accepted.

Cichlid fish inhabit a diverse range of environments that vary in the spectral content of light available for vision. These differences should result in adaptive selective pressure on the genes involved in visual sensitivity, the opsin genes. This study examines the evidence for differential adaptive molecular evolution in East African cichlid opsin genes due to gross differences in environmental light conditions. First, we characterize the selective regime experienced by cichlid opsin genes using a likelihood ratio test format, comparing likelihood models with different constraints on the relative rates of amino acid substitution, across sites. Second, we compare turbid and clear lineages to determine if there is evidence of differences in relative rates of substitution. Third, we present evidence of functional diversification and its relationship to the photic environment among cichlid opsin genes. We report statistical evidence of positive selection in all cichlid opsin genes, except short wavelength–sensitive 1 and short wavelength–sensitive 2b. In all genes predicted to be under positive selection, except short wavelength–sensitive 2a, we find differences in selective pressure between turbid and clear lineages. Potential spectral tuning sites are variable among all cichlid opsin genes; however, patterns of substitution consistent with photic environment–driven evolution of opsin genes are observed only for short wavelength–sensitive 1 opsin genes. This study identifies a number of promising candidate-tuning sites for future study by site-directed mutagenesis. This work also begins to demonstrate the molecular evolutionary dynamics of cichlid visual sensitivity and its relationship to the photic environment.

The advocacy coalition framework (ACF) pays special attention to "so-called" policy brokers when explaining policy change. However, this prominent policy approach neither clearly defines who the policy brokers are nor identifies under which institutional rules they have an influence on policy processes and outputs. This article thus formulates two theoretical hypotheses that complement the ACF and then proceeds to undertake the first empirical testing of these hypotheses within the Swiss climate policy (1990-2008). The empirical results show that, in the case under investigation, the <I>strategic interest-based behavior</I> of two policy brokers (i.e., one public administration and one political party), as well as two <I>institutionalized veto points</I> (i.e., optional referendum and parliamentary committee), are crucial factors explaining policy brokers' influence on policy process and change.

Background: Standard public health interventions to improve hand hygiene in communities with high levels of child mortality encourage community residents to wash their hands with soap at five separate key times, a recommendation that would require mothers living in impoverished households to typically wash hands with soap more than ten times per day. We analyzed data from households that received no intervention in a large prospective project evaluation to assess the relationship between observed handwashing behavior and subsequent diarrhea.<br /> Methods and Findings:Fieldworkers conducted a 5-hour structured observation and a cross-sectional survey in 347 households from 50 villages across rural Bangladesh in 2007. For the subsequent 2 years, a trained community resident visited each of the enrolled households every month and collected information on the occurrence of diarrhea in the preceding 48 hours among household residents under the age of 5 years. Compared with children living in households where persons prepared food without washing their hands, children living in households where the food preparer washed at least one hand with water only (odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.57–1.05), washed both hands with water only (OR = 0.67; 95% CI = 0.51–0.89), or washed at least one hand with soap (OR = 0.30; 95% CI = 0.19–0.47) had less diarrhea. In households where residents washed at least one hand with soap after defecation, children had less diarrhea (OR = 0.45; 95% CI = 0.26–0.77). There was no significant association between handwashing with or without soap before feeding a child, before eating, or after cleaning a child's anus who defecated and subsequent child diarrhea.<br /> Conclusions: These observations suggest that handwashing before preparing food is a particularly important opportunity to prevent childhood diarrhea, and that handwashing with water alone can significantly reduce childhood diarrhea.

Background: We analyzed data from the baseline assessment of a large intervention project to describe typical handwashing practices in rural Bangladesh, and compare measures of hand cleanliness with household characteristics.<BR/>Methods: We randomly selected 100 villages from 36 districts in rural Bangladesh. Field workers identified 17 eligible households per village using systematic sampling. Field workers conducted 5-hour structured observations in 1000 households, and a cross-sectional assessment in 1692 households that included spot checks, an evaluation of hand cleanliness and a request that residents demonstrate their usual handwashing practices after defecation.<BR/>Results: Although 47% of caregivers reported and 51% demonstrated washing both hands with soap after defecation, in structured observation, only 33% of caregivers and 14% of all persons observed washed both hands with soap after defecation. Less than 1% used soap and water for handwashing before eating and/or feeding a child. More commonly people washed their hands only with water, 23% after defecation and 5% before eating. Spot checks during the cross sectional survey classified 930 caregivers (55%) and 453 children (28%) as having clean appearing hands. In multivariate analysis economic status and water available at handwashing locations were significantly associated with hand cleanliness among both caregivers and children.<BR/>Conclusions: A minority of rural Bangladeshi residents washed both hands with soap at key handwashing times, though rinsing hands with only water was more common. To realize the health benefits of handwashing, efforts to improve handwashing in these communities should target adding soap to current hand rinsing practices.

Partial migration, in which a fraction of a population migrate and the rest remain resident, occurs in an extensive range of species and can have powerful ecological consequences. The question of what drives differences in individual migratory tendency is a contentious one. It has been shown that the timing of partial migration is based upon a trade-off between seasonal fluctuations in predation risk and growth potential. Phenotypic variation in either individual predation risk or growth potential should thus mediate the strength of the trade-off and ultimately predict patterns of partial migration at the individual level (i.e. which individuals migrate and which remain resident). We provide cross-population empirical support for the importance of one component of this model-individual predation risk-in predicting partial migration in wild populations of bream <em>Abramis brama</em>, a freshwater fish. Smaller, high-risk individuals migrate with a higher probability than larger, low-risk individuals, and we suggest that predation risk maintains size-dependent partial migration in this system.

This paper studies the conditions under which a given power distribution among coalitions of collective actors in political decision-making processes emerge. The distribution of power among actors is one of the basic dimensions of politics and is important because of its influence on the output of the decision-making processes. The paper distinguishes between ideal-types of power structures with a dominant coalition ("dominance") and structures with distributed power among several coalitions ("challenge"). It takes into account four conditions supposed to interact with each other, i.e. the degree of federalism of a policy project, its degree of Europeanization, its policy type (i.e. direct vs. indirect coercion), and the openness of the pre-parliamentary phase of the decision-making process. In order to assess the importance of these conditions, I compare the 11 most important decision-making processes in Switzerland between 2001 and 2006 by a Fuzzy-Set Qualitative Comparative Analysis (fsQCA). Results suggest that Europeanization or an open pre-parliamentary phase lead to a power structure of dominance, whereas only a specific combination of all four conditions is able to explain power structures of challenge. I argue that this is good news for the integration capacity of the Swiss political system.