Improving water security through rainwater harvesting: a case from Guatemala and the potential for expanding coverage

Municipal infrastructure for water supply and delivery often does not reach populations in rural and peri-urban areas. This article examines rainwater harvesting as a means of increasing water security in such areas, through the case of Guachtuq, a peri-urban community outside San Cristóbal, Alta Verapaz, Guatemala. The project team designed a rainwater harvesting system to improve three dimensions of water security: quantity, quality and access. The design was implemented for 12 households and evaluated for its contribution to water security and for the potential of expanding project coverage to the region and beyond. The system has improved water security. Several concerns remain, however, regarding the potential of expanding the project to other households in the region and beyond, including system cost, water quality and the individualization of public responsibility for water security.     

Establishing stability: exploring the meaning of ‘home’ for women who have experienced intimate partner violence

There is evidence that involuntary housing instability may undermine health and well-being. For women who have experienced intimate partner violence (IPV), achieving stability is likely as important for other groups, but can be challenging. Through our analysis of 41 interviews with women who have experienced low income and IPV, we argue that definitions of housing stability are multifaceted and for many centred on a shared understanding of the importance of creating an environment of “home”. We found that obtaining housing that satisfied material needs was important to women. However, in asking women to define what housing stability meant to them, we found that other factors related to ontological security and the home, such as safety, community, and comfort, contributed to women’s experiences of stability. Through our discussion of the importance these women placed on establishing stable homes, we argue that future research on women’s experiences with housing stability and IPV should include definitions of stability that capture both material security and women’s experiences with building emotionally stable homes.     

Outdoor Water Use as an Adaptation Problem: Insights from North American Cities

Recent efforts to influence the efficiency and timing of urban indoor water use through education, technology, conservation, reuse, economic incentives, and regulatory mechanisms have enabled many North American cities to accommodate population growth and buffer impacts of drought. It is unlikely that this approach will be equally successful into the future because the source of conservation will shift from indoor to outdoor use. Outdoor water is climate sensitive, difficult to measure, hard to predict, linked to other components of complex and dynamic urban resource systems, imbued with behavioral and cultural dimensions, and implicated in societal conflicts about climate risk, modern lifestyles, social justice, and future growth. Outdoor water conservation is not a traditional management problem focused on the water sector, assuming a stationary climate, and set aside from public debate. Instead, outdoor water is an adaptation problem, involving complex and uncertain system dynamics, the need for cross-sector coordination, strategies for dealing with climatic uncertainty, and mechanisms for engaging stakeholders with differing goals. This paper makes the case for treating outdoor water as an adaptation problem and offers a six-point strategy for how cities can better prepare their water systems for the uncertainties of climate and societal change.     

Natural Ligands of Porcine Olfactory Binding Proteins

Knowledge of endogenous ligands of olfactory binding proteins is a prerequisite for studying their role in odor and pheromone transduction. Here, we report the extraction, derivatization, and characterization by gas chromatography-mass spectrometry of the natural ligands of pig, Sus scrofa (L.), Von Ebner’s Gland protein (VEG) and odorant binding protein (OBP). We identified two isoforms (VEG1 and VEG2), which differed only by the linkage of an O-N-acetylglucosamine (O-GlcNac) group on VEG1. The natural ligands of VEG1 were characterized as two isomers of testosterone, whereas ligands of VEG2 and OBP were fatty acids or their derivatives. Our findings suggest that the binding specificity of VEG1 for steroids is governed by the presence of an O-GlcNac moiety on the protein. This specificity was confirmed by the binding of radiolabeled testosterone only by VEG1 in an in-gel binding assay. This is the first evidence for a post-translational modification in the process of odorant discrimination by olfactory binding proteins.     

Phosphotungstic heteropoly acid as efficient heterogeneous catalyst for solvent-free isomerization of α-pinene and longifolene

Silica-supported H₃PW₁₂O₄₀ (PW), the strongest heteropoly acid in the Keggin series, is an efficient, environmentally friendly heterogeneous catalyst for the liquid-phase isomerization of α-pinene and longifolene into their more valuable isomers – camphene and isolongifolene, respectively, which are intermediates in the synthesis of expensive fragrances. The reactions occur under solvent-free conditions in the temperature range of 80–100 °C, with low catalyst loadings (0.15–5 wt%) and high turnover numbers (up to 6000 per proton). The catalyst can be easily recovered and reused. No PW leaching is observed in the reaction system.     

Reduction of Listeria monocytogenes on frankfurters treated with lactic acid solutions of various temperatures

United States regulations require ready-to-eat meat and poultry processors to control Listeria monocytogenes using interventions which may include antimicrobials that reduce post-processing contamination by at least 1 log-cycle; if the treatment achieves ≥2 log reductions, the plant is subject to less frequent microbial testing. Lactic acid (LA) may be useful as a post-lethality intervention and its antimicrobial properties may increase with temperature of application. The aim of this study was to evaluate the effect of LA solution concentration and temperature on L. monocytogenes counts of inoculated frankfurters and to identify parameters (concentration, temperature, and time) that achieve 1 and 2 log-unit immediate reductions. Frankfurters were surface-inoculated with a 10-strain mixture of L. monocytogenes (4.4 ± 0.1 log CFU/cm²) and then immersed in distilled water or LA solutions (0–3%) of 4, 25, 40, or 55 °C for 0–120 s. A regression equation for L. monocytogenes reduction included significant (P < 0.05) effects by the terms of concentration, time, temperature, and the interaction of concentration and temperature; other tested parameters (other interactions, quadratic and cubic terms), within the experimental range examined, did not affect (P ≥ 0.05) the extent of reduction. Results indicated that the effectiveness of LA against L. monocytogenes, in addition to concentration, increased with solution temperature (in the range of 0.6–2.8 log CFU/cm²). The developed equation may allow processors to vary conditions of treatment with LA to achieve a 1 or 2 log-unit reduction of the pathogen and comply with United States regulations.     

植物乳杆菌发酵紫薯粉对酸面团面包的抗氧化特性及品质影响

采用紫薯粉和植物乳杆菌发酵紫薯粉制作富含花青素的面包,通过对比研究乳酸菌发酵紫薯粉对面包品质的影响;并探讨乳酸菌发酵紫薯粉对面包中花青素含量、总酚含量以及DPPH自由基清除率的影响。结果表明：相比紫薯粉面包,乳酸菌发酵紫薯粉使得面包pH值降低,总酸度(TTA)增加,面包比容有所减小,面包色度C*值增加而色相H*值减小,面包色泽由原来的浅紫色变为浅红色。感官评定的结果显示,采用紫薯粉或乳酸菌发酵紫薯粉制作的面包都为消费者所喜爱。同时,与紫薯粉面包相比,乳酸菌发酵紫薯粉面包的总酚含量和DPPH自由基清除率分别增加了90.8%和6.1%,增强了面包的抗氧化性。     

Rheology of liquid foods under shear flow conditions: Recently used models

Proper modeling of flow or viscosity curves as a function of shear rate is a useful tool in any engineering activity. The rheology of foods depends on the composition, processing to which they have been subjected and the state of dispersion in which they are found. Liquid foods are complex biosystems, that show non-Newtonian behavior under flow conditions. This review presents models used in recent decades to describe the experimental rheological behavior of various liquid foods, ranging from Newtonian fluids to the most complex. Some non-Newtonian parameters such as those of the Ostwald-de Waele, Bingham, Herschel–Bulkley, Casson, Cross, and Carreau models are summarized. Examples of thixotropic behavior described by the Weltman and Abu-Jdayil models are also presented. In each model, explanations based on the composition and dispersion state of the food are made. This is useful in innovative processing technologies and for scientists new to the field of food rheology. An attempt is made to exemplify and group the expected behavior for most fluid foods, including some for a dysphagia diet, depending on their composition or the dispersed system formed, which will be useful for professionals who wish to compare reported rheological parameters with those obtained experimentally.     

Properties of filmogenic solutions of gliadin crosslinked with 1-(3-dimethyl aminopropyl)-3-ethylcarbodiimidehydrochloride/N-hydroxysuccinimide and cysteine

In this study gliadin solutions were crosslinked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) and cysteine. The filmogenic solutions were studied through rheological, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and FTIR analysis. Gliadin modified by EDC/NHS showed lower viscosity values when compared with the gliadin/cysteine system and the non-modified gliadin system. Determination of amino groups in gliadin modified by EDC/NHS was carried out through the trinitrobenzenesulfonic acid (TNBS) method. The cast films were evaluated by FTIR analysis in order to detect structural changes in the secondary structure of protein. SDS-PAGE showed the formation of higher protein aggregates, indicating that cysteine promotes gliadin polymerization through covalent bonds (disulfide bonds). The TNBS analysis showed that non-chemically modified gliadin had higher amounts of ε-amino groups when compared with gliadin treated with EDC/NHS; however, both systems revealed similar amounts of amino groups for the whole range of glycerol content. The FTIR spectra for the films showed that the two crosslinking agents act by different mechanisms, promoting changes in the secondary structure of gliadin.