Assessing the consistency and microbiological effectiveness of household water treatment practices by urban and rural populations claiming to treat their water at home: a case study in Peru.

BACKGROUND: Household water treatment (HWT) can improve drinking water quality and prevent disease if used correctly and consistently by vulnerable populations. Over 1.1 billion people report treating their water prior to drinking it. These estimates, however, are based on responses to household surveys that may exaggerate the consistency and microbiological performance of the practice-key factors for reducing pathogen exposure and achieving health benefits. The objective of this study was to examine how HWT practices are actually performed by households identified as HWT users, according to international monitoring standards. METHODS AND FINDINGS: We conducted a 6-month case study in urban (n = 117 households) and rural (n = 115 households) Peru, a country in which 82.8% of households report treating their water at home. We used direct observation, in-depth interviews, surveys, spot-checks, and water sampling to assess water treatment practices among households that claimed to treat their drinking water at home. While consistency of reported practices was high in both urban (94.8%) and rural (85.3%) settings, availability of treated water (based on self-report) at time of collection was low, with 67.1% and 23.0% of urban and rural households having treated water at all three sampling visits. Self-reported consumption of untreated water in the home among adults and children <5 was common and this was corroborated during home observations. Drinking water of self-reported users was significantly better than source water in the urban setting and negligible but significantly better in the rural setting. However, only 46.3% and 31.6% of households had drinking water <1 CFU/100 mL at all follow-up visits. CONCLUSIONS: Our results raise questions about the usefulness of current international monitoring of HWT practices and their usefulness as a proxy indicator for drinking water quality. The lack of consistency and sub-optimal microbiological effectiveness also raises questions about the potential of HWT to prevent waterborne diseases

Seismic vulnerability assessment of clustered historical centers: fragility curves based on local collapse mechanisms analyses

open5noProtection and preservation of minor historical centres against earthquakes effects are not trivial tasks, particularly in the cases, quite common, of complex aggregate buildings. The paper aims at evaluating the seismic vulnerability of historical clustered buildings on a urban scale, through the analysis of local collapse mechanisms, carried out with a parametric approach. This procedure is applied to four historical centres of L’Aquila province struck by the 2009 earthquake. The identification of the significant parameters is related to the definition of representative typologies within the city centres. Each typology is characterized by recurring features, mainly recognizable with a survey performed outside the buildings. After the identification of the relevant aspects, local mechanisms of collapse analyses are carried out, by varying the parameters between defined range of values, in order to take into account possible uncertainties in the data collection. A set of fragility curves for each identified typology is defined and the obtained results are compared to the damage data gathered in the post-earthquake phase for the buildings. This approach allows for possible extensions to buildings that may be included in the typology categories here defined.openTaffarel, S.; Caliman, M.; Valluzzi, M.R; da Porto, F.; Modena, C.Taffarel, Sabrina; Caliman, M.; Valluzzi, MARIA ROSA; DA PORTO, Francesca; Modena, Claudi

Comportamento da conversão de glicose, galactose e lactose em ácido lático por grãos de kefir

Few studies have been reported on lactic acid production by kefir grains. Kefir has been widely associated with probiotic use due to its cell growth in food matrices such as milks, juices and sugary solutions. However, from industrial scale there are no reports of its use in lactic acid production. In this work, we carried out experiments to test and understand how glucose, galactose and lactose, during lactic-acid fermentation, were converted in lactic acid by kefir grains. Given the microbial complexity in coexistence in kefir grains, it is likely that kinetic studies are not the most appropriate for the positive or negative definition of the kefir use as a starter in the lactic acid fermentative production on an industrial scale. It was concluded that, although with a higher Lag phase, lactose was the substrate that best presented a product and cell conversion rate, although glucose and galactose can also be used as a substrate in the production of this carboxylic acid.Poucos estudos foram relatados sobre a produção de ácido lático pelos grãos de kefir. O kefir tem sido amplamente associado ao uso de probióticos devido ao seu crescimento celular em matrizes alimentares como leites, sucos e soluções açucaradas. Entretanto, em escala industrial não há relatos de sua utilização na produção de ácido lático. Neste trabalho, realizamos experimentos para testar e entender como a glicose, galactose e lactose, durante a fermentação láctica, são convertidas em ácido lático pelos grãos de kefir. Dada a complexidade microbiana em coexistência nos grãos de kefir, é provável que os estudos cinéticos não sejam os mais adequados para a definição positiva ou negativa do uso do kefir como starter na produção fermentativa de ácido lático em escala industrial. Concluiu-se que, embora com maior fase Lag, a lactose foi o substrato que melhor apresentou produto e taxa de conversão celular, embora glicose e galactose também possam ser utilizadas como substrato na produção desse ácido carboxílico

Enhancing nature conservation and health: Changing the focus to active pro-environmental behaviours

Most research about the promotion of pro-environmental behaviours has focused on actions conducted at home (e.g. energy saving). While acknowledging their relevance, the effect of such behaviours on the mitigation of two of the most relevant global environmental problems (climate change and biodiversity loss) is relatively small. We present a literature review with two main objectives. First is to introduce the concept of active pro-environmental behaviours. These are a combination of outdoor physical activities and pro-environmental behaviours. The latter involve behaviours that have a minimum impact on the environment, or even have positive consequences for the environment. Active commuting and tree planting are examples of active pro-environmental behaviours. The second objective is to discuss the relevance of active pro-environmental behaviours for people’s health and sustainability and, thereby, to encourage more research and efforts towards the promotion of these behaviours. We conclude by suggesting how stakeholders can promote active pro-environmental behaviours

Photonic band gap corrugated slow wave structure for THz sheet-beam vacuum electron devices

The use of photonic band gap (PBG) technology is investigated to alleviate some of the typical issues of vacuum electron devices at terahertz and is shown as particularly suitable for the use of large sheet beams. A full interaction structure including the slow wave structure and the coupler based on a tapered PBG corrugated waveguide is proposed for sheet beam backward wave oscillators (BWO). The case of a 346 GHz BWO is considered

Visualización de la función cuadrática

El artículo reportado es fruto de las reflexiones que se dieron durante nuestro primer semestre de Maestría en el Cinvestav – IPN. En este contexto, nuestro trabajo presenta una propuesta de una situación de aprendizaje en un entorno tecnológico. Para ello, se utilizaron como referencias las reflexiones con base a algunos elementos tales como el uso de las computadoras en el aula o bien, trabajos realizados en torno a la aplicación de programas educativos de orden tecnológico, como es el caso particular de Geogebra. La propuesta de nuestro trabajo, pone como objeto matemático a la función cuadrática de tal forma de presentar a la visualización del comportamiento gráfico de ésta, a partir de la variación de sus parámetros, utilizando el programa antes mencionado

Photonic crystal-coupler for sheet beam THz vacuum electron tubes

Photonic Crystal (PhC) technology was recently proposed as a compact and effective solution to improve the performance and ease the fabrication of terahertz vacuum electron devices. In particular, the introduction of defects in a bi-dimensional, all metallic PhC provides very effective transmission of the useful signal in a compact input/output coupler where a novel tunnel for sheet-beam injection/collection is realized. Simulation results are here experimentally validated via measurements on a Ku-band scaled model of the PhC-coupler which confirm the validity of the concept

Antipsychotics for the Treatment of Behavioral and Psychological Symptoms of Dementia (BPSD)

Behavioral and psychological symptoms of dementia (BPSD), i.e. verbal and physical aggression, agitation, psychotic symptoms (hallucinations and delusions), sleep disturbances, oppositional behavior, and wandering, are a common and potentially severe problem complicating dementia. Their prevalence is very high and it is estimated that up to 90% of patients with Alzheimer’s disease (AD) may present at least one BPSD. Beside the obvious impact on the quality of life of people with dementia, BPSD are responsible for increased risk of patient institutionalization and increased costs. Furthermore, they are associated with caregivers’ stress and depression. Drugs used include antipsychotics, antidepressants, anticonvulsivants, anxiolytics, cholinesterase inhibitors and N-methyl-D-aspartate receptor modulators. Among these, the most commonly used are anti-psychotics. These drugs have been used for many decades, but in the last years new compounds have been marketed with the promise of comparable efficacy but less frequent adverse effects (especially extra-pyramidal side effects). Their safety, however, has been challenged by data showing a potential increase in adverse cerebrovascular side effects and mortality. This review will summarize the pathophysiology and neuropharmacology of BPSD, it will describe the characteristics of the anti-psychotics most commonly used focusing on their efficacy and safety in BPSD