Hydropeaking indicators for characterization of the Upper-Rhone River in Switzerland

River channelization and the construction of high-head storage schemes have been the basis of agricultural and socio-economic development in many alpine regions. One example is the Upper-Rhone River in Switzerland. The Upper-Rhone's morphology changed considerably between 1863 and 1960 as a result of two major channelizations and, from 1950 on, the construction of a large number of high-head storage hydropower schemes in the catchment. These modifications have brought large benefits to the local population, at the cost, however, of substantial disturbances in aquatic and terrestrial ecosystems in and along the river. A primary factor behind these disturbances is the alteration of the natural flow regime, namely hydropeaking due to the operation of the high-head storage hydropower plants. For sustainable river-restoration projects on regulated rivers, scientists and engineers now widely accept the necessity of integrated management of the river. Different aspects such as river morphology, sediment management, water quality, temperature, and the naturally variable flow regime should be considered simultaneously. Mitigation of non-natural, sub-daily flow fluctuations due to hydropeaking is a crucial step in restoring natural flow regimes, but is especially challenging due to the economic constraints such mitigation places upon hydropower plants. With the goal of addressing this challenge, this paper proposes three indicators to describe the flow regime of rivers in alpine catchments with and without high-head storage hydropower plants. The indicators quantify: (1) the seasonal distribution and transfer of water, (2) sub-daily flow fluctuations, and (3) the intensity and frequency of flow changes. Indicators are evaluated in a case study of the Upper-Rhone River for pre- and post-impact situations, and the benefit of a multipurpose project reducing hydropeaking on hydrologic conditions is quantified. Furthermore, the paper explores the possibility of using these indicators to link aquatic and terrestrial ecosystem well being to their hydrolog

Bt176 corn in poultry nutrition: physiological characteristics and fate of recombinant plant DNA in chickens

A genetically modified Bt176 corn hybrid, which contains an insecticidal protein against the European corn borer, and its conventional, nonmodified counterpart were evaluated in 4 separate trials to verify substantial equivalence in feeding value and animal performance. Thirty-six individually kept laying hens and 3 replicates of 94 broiler chickens each, assigned to 12 cages, were fed 2 different hen and broiler diets containing either 60% conventional or 60% Bt176 corn. The nutrient compositions of the 2 corn hybrids and the 2 corn diets revealed no major differences. Furthermore, metabolism and performance data revealed no significant differences between the birds that received the conventional, nonmodified corn, and those that received the modified corn diets. The detection of the genetic modification, by PCR, in feed obtained from insect-resistant Bt corn, in tissues and products from animals fed Bt corn is described. In all evaluated chicken tissues of muscle, liver, and spleen, the corn-chloroplast ivr gene fragment was amplified. It can be deduced from these findings and from other studies that the transfer of DNA fragments into the body is a normal process that takes place constantly. Nevertheless, no recombinant plant DNA fragments such as recombinant bla or cry1A(b) fragments could be found. Bt-gene specific constructs from the Bt corn were not detected in any of the poultry samples, neither in organs, meat, nor egg

Investigation of the sugar content in wood hydrolysates with iodometric titration and UPLC-ELSD

ArticleAutohydrolysis of birch wood is a mild pretreatment process, which gives a notable yield of sugars – monosaccharides and oligosaccharides – in the aqueous hydrolysate, while a solid lignocellulose fraction can be further processed into other valuable products within a biorefinery concept. In this work two analytical methods – iodometric titration and ultra-high performance liquid chromatography with evaporative light scattering detection (UPLC-ELSD) – have been optimized and compared for the determination of the sugar content in series of birch wood hydrolysates. The results of both methods were consistent and showed that the highest yield of sugars, mostly xylose, was obtained by hydrolysis at 180 °C after 75 min

Controls on Interspecies Electron Transport and Size Limitation of Anaerobically Methane-Oxidizing Microbial Consortia

About 382 Tg yr⁻¹ of methane rising through the seafloor is oxidized anaerobically (W. S. Reeburgh, Chem Rev 107:486–513, 2007, https://doi.org/10.1021/cr050362v), preventing it from reaching the atmosphere, where it acts as a strong greenhouse gas. Microbial consortia composed of anaerobic methanotrophic archaea and sulfate-reducing bacteria couple the oxidation of methane to the reduction of sulfate under anaerobic conditions via a syntrophic process. Recent experimental studies and modeling efforts indicate that direct interspecies electron transfer (DIET) is involved in this syntrophy. Here, we explore a fluorescent in situ hybridization-nanoscale secondary ion mass spectrometry data set of large, segregated anaerobic oxidation of methane (AOM) consortia that reveal a decline in metabolic activity away from the archaeal-bacterial interface and use a process-based model to identify the physiological controls on rates of AOM. Simulations reproducing the observational data reveal that ohmic resistance and activation loss are the two main factors causing the declining metabolic activity, where activation loss dominated at a distance of <8 μm. These voltage losses limit the maximum spatial distance between syntrophic partners with model simulations, indicating that sulfate-reducing bacterial cells can remain metabolically active up to ∼30 μm away from the archaeal-bacterial interface. Model simulations further predict that a hybrid metabolism that combines DIET with a small contribution of diffusive exchange of electron donors can offer energetic advantages for syntrophic consortia

Risk management and communication in informal dairy sector in Côte d’Ivoire: Options for sustainable livelihoods

Intervention in food and nutrition was the best investment for our collective future in terms of managing co-morbidity in population. This investment should combine agricultural system with health and education. Fermented dairy products (FDP) played an important role for prolonged shelf life, microbial safety and nutrition. FDP was proved to be contaminated in Kenya, Somalia, Mali and Côte d'Ivoire by foodborne pathogens including Staphylococcus aureus and Escherichia coli. Recently, it was showed that FDP was predominated by a novel Streptococcus infantarius subsp. infantarius (Sii) variant. Sii-produced bacteriocin and fermentation activity could contribute to the suppression of pathogens and possibly mitigate socioeconomic and health risks. However, Sii as member of Streptococcus bovis group was associated with human and animal infections. Therefore, a potential application of Sii as adapted African starter culture for enhanced food safety required a thorough safety assessment. In order to improve hygiene and quality as well as to increase production for school canteens, urban consumption and sustainable livelihoods, a cross-sectional study was conducted in Korhogo (Côte d’Ivoire) from May to August 2014. The objective was to assess local technologies and the dairy value chain in relation to Sii prevalence, followed by a participatory stakeholder workshop to validate findings and derive adapted interventions. The study showed that the dairy value chain contributed to livelihoods and household income. About 90% of milk produced (range: 12-44 liters/collector) were sold via collectors, generating 6-20 Euros per day shared among herder, collector and vendor. The remaining 10% were consumed within the household. However, dairy production was low and scattered due to informal practices resulting in poor quality product. Basic hygiene such as cleaning, washing, disinfecting was lacking. Milk quality depreciated with the local practices, access to clean water and energy. Future interventions identified by stakeholders comprised (i) awareness on local dairy hygiene and nutritional value for the population especially school children, (ii) stakeholders organization around cooperative to develop sustainable dairy model (public dairy with private management); (iii) promote healthy milk products for school canteen programme in Korhogo through adapted local dairy technology

The evolution of early diagenetic processes at the Mozambique margin during the last glacial-interglacial transition

The Mozambique continental margin experienced large variations in sedimentation rates, primarily due to re-routing of sediment deposition from the Zambezi River during the last glacial-Holocene transition. As changes in sediment accumulation and organic matter deposition impose a strong control on the formation of authigenic minerals in the sediment, the distribution of these minerals may reflect the regional paleoenvironmental and paleoclimatic evolution. Combining geochemical analyses of porewaters and sediments with a reactive transport modeling approach, we reconstruct the depositional history and its effect on pyrite formation and other biogeochemical transformations at a site on the Mozambique margin over the past 27 kyr. Fitting the model to match the observed geochemical patterns, most importantly authigenic pyrite, allowed for the reconstruction of past sulfate-methane transition zone depth, which migrated in response to changes in the sediment accumulation and organic matter deposition. Changes in sediment deposition quickly affected organoclastic sulfate reduction and associated pyrite formation, but the effect on anaerobic methane oxidation and subsequent pyrite formation occurred with a lag on the order of thousands of years. Model results reveal a transition from high diagenetic reaction rates representative of near-shore depositional environments during the late glacial maximum, to a setting typical of offshore sediments with low reaction rates at the present day. Notably, the remnants of methane and dissolved iron pools produced in the past still shape the diagenetic processes at and below the sulfate-methane transition zone today. Since deglacial shelf-flooding and corresponding changes in sediment deposition occurred along continental margins worldwide, our analysis highlights the important role of non-steady state diagenesis in continental margin sediments and its relevance for paleoceanographic interpretation of sediment cores experiencing strong variations in sediment input

A novel SMC-like protein, SbcE (YhaN), is involved in DNA double-strand break repair and competence in Bacillus subtilis

Bacillus subtilis and most Gram positive bacteria possess four SMC like proteins: SMC, SbcC, RecN and the product of the yhaN gene, termed SbcE. SbcE is most similar to SbcC but contains a unique central domain. We show that SbcE plays a role during transformation in competent cells and in DNA double-strand break (DSB) repair. The phenotypes were strongly exacerbated by the additional deletion of recN or of sbcC, suggesting that all three proteins act upstream of RecA and provide distinct avenues for presynapsis. SbcE accumulated at the cell poles in competent cells, and localized as a discrete focus on the nucleoids in 10% of growing cells. This number moderately increased after treatment with DNA damaging agents and in the absence of RecN or of SbcC. Damage-induced foci of SbcE arose early after induction of DNA damage and rarely colocalized with the replication machinery. Our work shows that SMC-like proteins in B. subtilis play roles at different subcellular sites during DNA repair. SbcC operates at breaks occurring at the replication machinery, whereas RecN and SbcE function mainly, but not exclusively, at DSBs arising elsewhere on the chromosome. In agreement with this idea, we found that RecN-YFP damage-induced assemblies also arise in the absence of ongoing replication