Optimizing sampling location for water quality degradation monitoring in distribution systems: Assessing global representativeness and potential health risk.

Selecting the optimal monitoring points in a water distribution network is challenging due to the complex spatiotemporal variability of water quality degradation. The lack of a standardized methodology for monitoring point selection forces operators to rely on general recommendations, historical data and professional experience, which can mask water quality problems and increase the risk to consumers. This study proposes a new methodology to optimize the selection of monitoring points in distribution networks. The method considers the spatiotemporal degradation of water quality, the definition of representative zones and two selection criteria: global representativeness and potential health risk. Representative zones were determined for each node of the network based on hydraulic paths and their water quality spatial variability. Part of the distribution network in Quebec City, Canada was used as the case study, in which four water quality parameters were investigated: free chlorine residual (FRC), heterotrophic plate counts (HPC), trihalomethanes (THMs) and haloacetic acids (HAAs). Seasonal variabilities (summer and winter) were also analyzed. The results obtained for the two criteria and for both seasons were compared, and methodological and practical recommendations were established for dynamic monitoring programs that respond to the needs of operators.

Domestic access to water in a decentralized truck-to-cistern system: a case study in the Northern Village of Kangiqsualujjuaq, Nunavik (Canada).

Municipal water supply through truck-to-cistern systems is common in northern Canada. Household satisfaction and concerns about water services likely impact user preferences and practices. This case study explores household perspectives and challenges with regard to domestic access to water in a decentralized truck-to-cistern system. A case study was conducted in the Northern Village of Kangiqsualujjuaq, Nunavik (Quebec, Canada). A paper-based questionnaire was completed by 65 households (one quarter of the population). Many households (37%) reported not drinking tap water from the truck-to-cistern system. Chlorine taste was a frequently reported concern, with those households being significantly less likely to drink water directly from the tap (p = 0.002). Similarly, households that reported a water shortage in the previous week (i.e., no water from the tap at least once) (33%) were more likely to express dissatisfaction with delivered water quantity (rs = 0.395, p = 0.004). Interestingly, 77% of households preferred using alternative drinking water sources for drinking purposes, such as public tap at the water treatment plant, natural sources or bottled water. The study underscores the importance of considering household perspectives to mitigate the risks associated with service disruptions and the use of alternative sources for drinking purposes.

Ensemble machine learning using hydrometeorological information to improve modeling of quality parameter of raw water supplying treatment plants.

Source and raw water quality may deteriorate due to rainfall and river flow events that occur in watersheds. The effects on raw water quality are normally detected in drinking water treatment plants (DWTPs) with a time-lag after these events in the watersheds. Early warning systems (EWSs) in DWTPs require models with high accuracy in order to anticipate changes in raw water quality parameters. Ensemble machine learning (EML) techniques have recently been used for water quality modeling to improve accuracy and decrease variance in the outcomes. We used three decision-tree-based EML models (random forest [RF], gradient boosting [GB], and eXtreme Gradient Boosting [XGB]) to predict two critical parameters for DWTPs, raw water Turbidity and UV absorbance (UV254), using rainfall and river flow time series as predictors. When modeling raw water turbidity, the three EML models (rRF-Tu2=0.87, rGB-Tu2=0.80 and rXGB-Tu2=0.81) showed very good performance metrics. For raw water UV254, the three models (rRF-UV2=0.89, rGB-UV2=0.85 and rXGB-UV2=0.88) again showed very good performance metrics. Results from this study suggest that EML approaches could be used in EWSs to anticipate changes in the quality parameters of raw water and enhance decision-making in DWTPs.

Preserved VPS13A distribution and expression in Huntington's disease: divergent mechanisms of action for similar movement disorders?

VPS13A disease and Huntington's disease (HD) are two basal ganglia disorders that may be difficult to distinguish clinically because they have similar symptoms, neuropathological features, and cellular dysfunctions with selective degeneration of the medium spiny neurons of the striatum. However, their etiology is different. VPS13A disease is caused by a mutation in the VPS13A gene leading to a lack of protein in the cells, while HD is due to an expansion of CAG repeat in the huntingtin (Htt) gene, leading to aberrant accumulation of mutant Htt. Considering the similarities of both diseases regarding the selective degeneration of striatal medium spiny neurons, the involvement of VPS13A in the molecular mechanisms of HD pathophysiology cannot be discarded. We analyzed the VPS13A distribution in the striatum, cortex, hippocampus, and cerebellum of a transgenic mouse model of HD. We also quantified the VPS13A levels in the human cortex and putamen nucleus; and compared data on mutant Htt-induced changes in VPS13A expression from differential expression datasets. We found that VPS13A brain distribution or expression was unaltered in most situations with a decrease in the putamen of HD patients and small mRNA changes in the striatum and cerebellum of HD mice. We concluded that the selective susceptibility of the striatum in VPS13A disease and HD may be a consequence of disturbances in different cellular processes with convergent molecular mechanisms already to be elucidated.

Year-round monitoring of three water sources in Québec, Canada, reveals site-specific differences in conditions for Cryptosporidium and Giardia contamination.

Cryptosporidium and Giardia are protozoan parasites responsible for gastrointestinal illnesses in humans and in animal species. The main way these parasites are transmitted is by ingestion of their (oo)cysts in drinking water. Monitoring (oo)cysts in water sources is beneficial to evaluate the quality of raw water supplying treatment plants. Currently, the only standardized protocol to enumerate these parasites from water samples is United States Environmental Protection Agency (USEPA) Method 1623.1. With this method, we monitored three major water sources in Quebec over a year to assess temporal and geographical variations of these parasite (oo)cysts. These three water sources have independent watersheds despite being in the same region. We found a general pattern for Giardia, with high concentrations of cysts during cold and transition periods, and significantly lower concentrations during the warm period. Cryptosporidium's concentration was more variable throughout the year. Statistical correlations (Pearson's correlation coefficients) were established between the concentration of each parasite and various environmental parameters. The three study sites each showed unique factors correlating with the presence of both protozoa, supporting the idea that each water source must be seen as a unique entity with its own particular characteristics and therefore, must be monitored independently. Although some environmental parameters could be interesting proxies to the parasitic load, no parameter was strongly correlated throughout the whole sampling year and none of the parameters could be used as a single proxy for all three studies sources.

Brain-gut photobiomodulation restores cognitive alterations in chronically stressed mice through the regulation of Sirt1 and neuroinflammation.

BACKGROUND: Chronic stress is an important risk factor for the development of major depressive disorder (MDD). Recent studies have shown microbiome dysbiosis as one of the pathogenic mechanisms associated with MDD. Thus, it is important to find novel non-pharmacological therapeutic strategies that can modulate gut microbiota and brain activity. One such strategy is photobiomodulation (PBM), which involves the non-invasive use of light. OBJECTIVE/HYPOTHESIS: Brain-gut PBM could have a synergistic beneficial effect on the alterations induced by chronic stress. METHODS: We employed the chronic unpredictable mild stress (CUMS) protocol to induce a depressive-like state in mice. Subsequently, we administered brain-gut PBM for 6 min per day over a period of 3 weeks. Following PBM treatment, we examined behavioral, structural, molecular, and cellular alterations induced by CUMS. RESULTS: We observed that the CUMS protocol induces profound behavioral alterations and an increase of sirtuin1 (Sirt1) levels in the hippocampus. We then combined the stress protocol with PBM and found that tissue-combined PBM was able to rescue cognitive alterations induced by CUMS. This rescue was accompanied by a restoration of hippocampal Sirt1 levels, prevention of spine density loss in the CA1 of the hippocampus, and the modulation of the gut microbiome. PBM was also effective in reducing neuroinflammation and modulating the morphology of Iba1-positive microglia. LIMITATIONS: The molecular mechanisms behind the beneficial effects of tissue-combined PBM are not fully understood. CONCLUSIONS: Our results suggest that non-invasive photobiomodulation of both the brain and the gut microbiome could be beneficial in the context of stress-induced MDD.

Results of consevative treatment of breast cancer in low risk women with hypofractionated radiotherapy

Objetivos: Actualmente la irradiación de toda la mama después de una intervención quirúrgica conservadora sigue siendo un procedimiento estándar en el cáncer de mama, en la que clásicamente se administra una dosis de 50 Gy con fraccionamiento de 2 Gy. Sin embargo, diferentes dosis y fraccionamiento han demostrado al menos la misma eficacia. El objetivo principal del estudio fue determinar la tasa de recidiva local en pacientes sometidas a cirugía conservadora y radioterapia postoperatoria hipofraccionada. Los objetivos secundarios fueron la incidencia y el grado de toxicidad aguda y tardía. Pacientes y métodos: Desde enero de 2004 a diciembre de 2006, se seleccionó a 122 pacientes para radioterapia hipofraccionada con las características siguientes: edad ≥ 50 años, estadio temprano, margen de resección libre de tumor y espesor de la mama < 23 cm. La dosis administrada fue 42,5 Gy con fraccionamiento de 2,66 Gy por sesión. Resultados: Con una mediana de seguimiento de 58,29 meses, 116 (95,08%) pacientes están vivas: 114 libres de enfermedad y 2 con metástasis óseas. La recidiva local a 5 años fue 1,64% y sólo un caso (0,81%) presentó recidiva regional. Hubo un 2,46% de pacientes con segundo tumor primario y un 4,91% con metástasis. La toxicidad, tanto aguda como tardía, ha sido leve. Conclusiones: La radioterapia hipofraccionada en pacientes de riesgo bajo proporciona los mismos beneficios que el tratamiento clásico con una baja toxicidad aguda y tardía (AU)

Aims: Whole breast irradiation, typically administered at a dose of 50 Gy in 2 Gy fractions after conservative surgery, continues to be a standard procedure in breast cancer. However, different doses and fractionation have shown to be at least as effective. The main objective of this study was to determine the rate of local recurrence in patients undergoing conservative surgery and hypofractionated postoperative radiotherapy. The secondary objectives were to determine the incidence and grade of both acute and delayed toxicity. Patients and methods: From January 2004 to December 2006, 122 patients who had the following characteristics were selected to receive hypofractionated radiotherapy to the whole breast: age ≥ 50 years, early stage, tumour free resection margins ≥ 10 mm, thickness of the breast ≤ than 23 cm. The total dose was 42.5 Gy with fractionation of 2.66. Results: With a median follow up of 58.29 months, 116 (95.08%) patients were alive: 114 were free of disease and 2 had metastases. The 5 year local recurrence rate was 1.64%, and only in one case (0.81%) there was a regional recurrence. Only 2.46% of the patients developed a second primary tumour. Distant metastases were present in 4.91%. Toxicity, both acute and late, was mild (grade 1-2). Conclusions: Hypofractionated radiotherapy, in patients with low risk breast cancer after conservative surgery, provides the same benefits as the classical treatment with a low acute, as well as and delayed, toxicity (AU)

Subproductos de la desinfección del agua potable: formación, aspectos sanitarios y reglamentación / Disinfection by-products in drinking water: occurrence, health issues and regulations

La desinfección del agua tiene como objetivo la eliminación y la desactivación de microbios patógenos. Los desinfectantes utilizados predominantemente en la potabilización del agua son el cloro y sus derivados. Además de desactivar los organismos patógenos, el cloro reacciona con la materia orgánica presente en el agua, lo que genera subproductos de cloración, específicamente compuestos orgánicos sintéticos. Estos subproductos pueden tener potencialmente efectos en la salud humana. Otros desinfectantes han sido utilizados como alternativa al cloro, pero cada uno de ellos forma igualmente subproductos; ejemplos de éstos son la cloramina, el ozono y el bióxido de cloro. En este artículo se presentan los mecanismos y los factores que determinan la formación y la presencia de subproductos de la desinfección en el agua potable. Se discute igualmente los problemas de salud pública que estos subproductos pueden ocasionar y se presentan los aspectos normativos para estos contaminantes y estrategias para limitar su presencia en el agua distribuida a la población.

Biopsia pulmonar en falla respiratoria aguda

me presenta una revisión retrospectiva de pacientes con enfermedad pulmonar de menos de 40 días de evolución, con infiltrados pulmonares difusos e índice de lesión pulmonar (I.L.P) mayor de 2.5 a quienes se les practicó biopsia pulmonar. Se calculó el APACHE II; el I.L.P., el índice (a/A)O2 y la PaO2/FiO2, el ingreso y el día de la biopsia y se buscó el peor I.L.P. y el peor I(a/A)O2 durante la hospitalización. Se presentan 17 pacientes. Se hizo biopsia transbronquial en 13 casos y fue diagnóstica en 10 (76 por ciento), y biopsia abierta en cinco casos, disgnóstica en todos, sin complicaciones mayores. Al separar los pacientes en vivos y muertos (6) la única de las variables estudiadas que fue diferente entre los dos grupos fue el APACHE II (17.8 muertos vs 11.2 vivos P=0.015). En nueve casos se identificó una enfermedad pulmonar tratable y murieron 3 (33 por ciento) y en los 6 casos con enfermedad pulmonar no tratable murieron dos (33 por ciento). Nueve pacientes ingresaron por enfermedad pulmonar, tres murieron; en seis la enfermedad pulmonar era tratable y murió uno, en tres no y murieron dos; ocho ingresaron por enfermedad no pulmonar y murieron tres; en este último grupo, el APACHE II fue mayor en los muertos y la lesión pulmonar mayor en los vivos; en tres la enfermedad pulmonar era tratable y murieron dos; en cinco casos no era tratable y murió uno. Conclusión: Se hizo biopsia transbronquial y/o abierta sin complicaciones mayores y se logró el diagnóstico histológico en 88 por ciento de los casos. En los pacientes que murieron fue mayor fue mayor el APACHE II y no se diferencian de los vivos en la severidad de la lesión pulmonar. La mortalidad fue igual si la enfermedad pulmonar era tratable o no.

Diagnóstico clínico del nódulo único del tiroides

El examen físico sigue siendo en la actualidad el elemento fundamental en el diagnóstico de los nódulos solitarios del tiroides. Aunque es usual que el nódulo único del tiroides no ocasione síntomas puede, sin embargo, producir en algunos casos dolor, tos, ronquera, disnea, disfagía, síntomas neurológicos, fiebre, malestar, leucocitos y velocidad de sedimentación de los eritrocitos aumentada. La tasa del metabolismo basal, la captación de I 131 y la eliminación urinaria de este isótopo, el yodo extraido con butanol sólo se limitan en el nódulo solitario a ofrecer información sobre la evolución del paciente o su respuesta al tratamiento. Los estudios radiológicos permiten observar la compresión o el desplazamiento de la tráque, la presencia de calcificaciones y determinar el origen de una disfagía (AU)