Future bottlenecks in international river basins: where transboundary institutions,population growth and hydrological variability intersect

Using global data, this article examines the nexus of transboundary flood events and future social vulnerability. Which international river basins are forecast to experience an increase in both hydrological variability and population in the future, but currently lack institutional provisions to deal with these shared events? Concentrations of elevated risk are found in several basins in Central Asia, Central America and Central Africa. The article ends by highlighting transboundary basins that merit further investigation and possibly additional institution building to reduce urban flood risk.     

Microglial Cell Activation Increases Saturated and Decreases Monounsaturated Fatty Acid Content,but Both Lipid Species are Proinflammatory

Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation.     

Single passage in mouse organs enhances the survival and spread of Salmonella enterica

Intravenous inoculation of Salmonella enterica serovar Typhimurium into mice is a prime experimental model of invasive salmonellosis. The use of wild-type isogenic tagged strains (WITS) in this system has revealed that bacteria undergo independent bottlenecks in the liver and spleen before establishing a systemic infection. We recently showed that those bacteria that survived the bottleneck exhibited enhanced growth when transferred to naive mice. In this study, we set out to disentangle the components of this in vivo adaptation by inoculating mice with WITS grown either in vitro or in vivo. We developed an original method to estimate the replication and killing rates of bacteria from experimental data, which involved solving the probability-generating function of a non-homogeneous birth–death–immigration process. This revealed a low initial mortality in bacteria obtained from a donor animal. Next, an analysis of WITS distributions in the livers and spleens of recipient animals indicated that in vivo-passaged bacteria started spreading between organs earlier than in vitro-grown bacteria. These results further our understanding of the influence of passage in a host on the fitness and virulence of Salmonella enterica and represent an advance in the power of investigation on the patterns and mechanisms of host–pathogen interactions.     

Rapid microwave synthesis of the iron arsenides NdFeAsO and NdFe0.9Co0.1AsO

The future of iron pnictide superconductors in technology is still undecided. While these materials are now known to possess relatively high critical temperatures and critical magnetic fields, processing methods for these superconductors are still in the development stage. Recently we have been investigating possible ways to speed up the synthetic process for obtaining polycrystalline iron arsenide superconductors and other transition metal pnictides. Here we report the synthesis of NdFeAsO and NdFe_0.9Co_0.1AsO in less than 1 h total exposure to microwave radiation using an additional microwave susceptor to surround the reaction ampoule. Structure and property measurements reveal the samples to be of high quality and superconducting when Co doped.     

Forensically Robust Detection of the Presence of Morpholine in Apples—Proof of Principle

Morpholine is a precursor of carcinogenic nitrosamines and although the possibility of their formation in the human stomach after ingestion of morpholine-treated apples is reported as highly unlikely morpholine has not been authorised as a food additive in the EU. Methods for its detection are required since it is permitted in other jurisdictions and may be present on food through direct treatment of fruit with waxes containing the compound, through steam treatment during processing or from packaging. Methods using derivatising agents with the inclusion of UV chromophores such as dansyl chloride yield good separation and high sensitivity but with mass spectrometric fragment ions predominantly originated from the derivatising group rather than the morpholine moiety. An amine acetylation derivatisation method is proposed from which fragment ions originating from the morpholine group are detected using widely available GC–MS. With full validation, a forensically robust confirmation of the presence of morpholine via its N-acetyl derivative is possible in support of regulatory analysis.     

Development of semitransparent wood‐polymer composites

A new material has been developed consisting of pieces of wood embedded within a matrix of acrylic polymer, resulting in a transparent or semitransparent wood‐based product. This material presents quite appealing aesthetic features, thereby opening new possibilities for decorative applications. Because acrylic and methacrylic monomers are in the liquid state at room temperature, it is possible to introduce wood (in the current case, walnut wood) into a mixture of acrylic (hydroxypropyl acrylate) and/or methacrylic monomers (methyl methacrylate and 2‐hydroxyethyl methacrylate) along with a plasticizer (dioctyl phthalate) in the presence of a chemical initiator (benzoyl peroxide). A transparent polymeric matrix with dispersed wood is then obtained through bulk free‐radical polymerization. Introducing this reaction mixture along with pieces of wood into a mold results in a wood‐polymer composite. A 2^4?1 experimental fractional factorial design was implemented to study the importance of the composition of these materials on several relevant properties. The sheets produced were characterized by tensile testing, dynamic mechanical thermal analysis, thermal gravimetric analysis, and heat deflection temperature. The models obtained for predicting each property pointed to valuable insights regarding the influential constituents. In particular, our results suggested that monomers to be used in future applications of this material should be selected in terms of their cost and the desired flexibility for the final product, not in terms of their polarity. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers     

Amphiphilic drug interactions with model cellular membranes are influenced by lipid chain-melting temperature

Small-molecule amphiphilic species such as many drug molecules frequently exhibit low-to-negligible aqueous solubility, and generally have no identified transport proteins assisting their distribution, yet are able to rapidly penetrate significant distances into patient tissue and even cross the blood–brain barrier. Previous work has identified a mechanism of translocation driven by acid-catalysed lipid hydrolysis of biological membranes, a process which is catalysed by the presence of cationic amphiphilic drug molecules. In this study, the interactions of raclopride, a model amphiphilic drug, were investigated with mixtures of biologically relevant lipids across a range of compositions, revealing the influence of the chain-melting temperature of the lipids upon the rate of acyl hydrolysis.     

Strained fermented milks – A review of existing legislative provisions,survey of nutritional labelling of commercial products in selected markets and terminology of products in some selected countries

A survey of the information contained in the labels of 109 commercial concentrated fermented milks from the Eastern Mediterranean, Australasia, the United Kingdom, Ireland, the United States of America and Canada plus Skyr (from Iceland), Ymer (from Denmark) and Chakka (from India) was carried out in late 2012 and early 2013. There were substantial differences in composition. The carbohydrate, fat and protein contents ranged between 1–12, 0–20 and 3.3–11 g/100 g, respectively. Considering the compositional data of the product and existing legislative provisions, a typical strained product should have a protein content of ≥8 g/100 and ~5 g/100 g of carbohydrates, and it would be appropriate to name such products as ‘strained yoghurt’, ‘Greek strained yoghurt’ and/or ‘Labneh’. A higher content of carbohydrate would suggest that the product was made using the product formulation method (i.e. without straining the fermentate), or the milk base had been fortified with skimmed milk before straining the fermentate to enhance the yield of the product, and such products should be known, for example, as ‘Greek‐style yoghurt’. It was also observed in some of the samples that the nomenclature of the starter cultures did not conform to recommendations of the International Union of Microbiological Societies (IUMS). Manufacturers could address such issues to minimise consumer confusion.