Comparison of Aedes aegypti arbovirus transmission thresholds in two communities with differing water supply infrastructure.

BACKGROUND: To assess whether the 'economic boom' in the tropical seaport city of Barranquilla improved tapped water supplies to socio-economically poor neighbourhoods resulting in: (1) their reduced use for domestic water-storage in large (> 1,000-litre) custom-made cement tanks which are their principal Aedes aegypti breeding sites and (2) their pupae/person index (PPI) values to below their established 0.5-1.5 PPI arbovirus transmission-threshold value, compared to matched neighbourhoods in the: (a) pre-economic boom (2004) period in Barranquilla and (b) economically-neglected seaport city of Buenaventura. METHODS: The simple, accurate and robust water surface sweep-net/calibration factor or total count methods were used to determine the total Ae. aegypti pupae numbers in greater or less than 20-litre water-holding container types located 'inside' or 'outside' these neighbourhood premises. The women residents also participated in questionnaire-based responses about their domestic water supplies, water-storage and maintenance and mosquito life stages and disease transmission knowledge, to subsequently plan appropriate resident education programmes. Microsoft Excel 8.0 with OpenEpi was used to determine the samples sizes and the statistical values. RESULTS: Tapped water supplies to the three poor Barranquilla neighbourhoods were dramatically increased from 2004 to 2023 resulting in their residents significantly reducing their: (a) large cement water-storage tanks from 1 per 6.9 (2004) to 1 per 31.2 (2020) premises (z = 10.5: p = 0) and (b) PPI values to 0.16, 0.19 and 0.53 (mean: 0.29: 95% CI ± 0.4) in each study neighbourhood. In contrast, tapped water supplies remained inadequate in the Buenaventura neighborhoods, thereby resulting in their continued use of many large (> 1,000-litre) water-storage containers (Barranquilla: 1 per 31.2 and Buenaventura: 1 per 1.5 premises: z = - 9.26: p = 0), with unacceptably high 0.81, 0.88 and 0.99 PPI values in each study neighbourhood (mean 0.89: 95% CI ± 0.12). CONCLUSIONS: Improved tapped water supplies resulted in reduced numbers of large custom-made stoneware water-containers, as are employed by poor residents throughout the world, as well as their Ae. aegypti PPI transmission threshold values which, together with appropriate residents' education programmes, are also urgently to reduce to prevent/reduce Ae. aegypti transmitted human diseases globally.

Multi-sensor geodetic observations for drought characterization in the Northeast Atlantic Eastern Hydrographic Region, Brazil.

The lowest water availability area in Brazil is the Northeast Atlantic Eastern Hydrographic Region (NAERH). It plays a fundamental role in the lives of 24.1 million inhabitants spread throughout 874 cities. Drought is recurrent in this semiarid climate, affecting agriculture, biodiversity, the ecosystem and other environmental spheres. Therefore, the goal of this research is to combine different drought indexes to quantify drought intensity and duration in the NAERH. Besides the traditionally used rainfall data, multi-temporal data from the Gravity Recovery and Climate Experiment (GRACE) and Global Positioning System (GPS) were also used. The indexes are the Combined Climatic Deviation Index (CCDI), Drought Severity Index (DSI) and Vertical Crustal Deformation Index (DIVCD). The Standardized Precipitation Index (SPI) was used for validation of the other indexes through the Spearman rank correlation, which retrieved ρ = 0.76 and 0.68 between the CCDI and the SPI-03/06. On the other hand, DSI correlated with the SPI-24/36 with ρ = 0.67/0.75. Despite limitations, the DIVCD accurately detected the frequencies of hydrological droughts. All indexes identified the last severe drought from 2012 to 2018, and its persistence throughout 2019 and 2020. The combined indexes approach reveals nuances of the indexes, improving the baseline to thoroughly understand drought at different temporal scales.

Heavy metal concentrations in rivers and drinking water of Esmeraldas (Ecuador) under an intermittent water supply service.

Universal access to safe water is a major global goal, but these efforts could be at stake because drinking water sources are becoming polluted in many developing countries. Chlorine, major ions, and heavy metals were measured in rivers and drinking water of Esmeraldas because potential pollution sources raise concerns about the quality of the water supply, and because users have developed strategies to cope with water shortages including collecting river water and water distributed by tankers, storing water at home, and consuming commercial bottled water. We sampled water from the water distribution system (WDS) and the Esmeraldas and Teaone rivers including the intake to the potabilization plant, water distributed by tankers, and commercial bottled water. Most of the samples collected from the Esmeraldas and Teaone rivers, the WDS, and tankers complied with drinking water standards, but higher concentration of cadmium and other metals in the eastern part of the city is an indication of corrosion inside the WDS. Commercial bottled and WDS water showed similar heavy metal concentrations, but regular consumption of some brands may lead to higher exposure to arsenic and mineral deficiencies. Chlorine concentrations in the water supplied by the WDS were below the values required for safe disinfection, and in-house chlorination is uncommon in the city. Strengthening pollution control in the Esmeraldas river, monitoring corrosion of the WDS, and promoting point-use chlorination and better water handling practices are required to secure a safer water supply in the long term.

Optimizing Household Water Decisions for Managing Intermittent Water Supply in Mexico City.

One billion people worldwide experience intermittent water supply (IWS), in which piped water is delivered for limited durations. Households with IWS must invest in water storage infrastructure and often rely on multiple sources of water; therefore, these household-level purchasing and infrastructure decisions is a critical component of water access. Informed by interviews with IWS households, we use radial basis function networks, a type of artificial neural network, to determine optimal household water management decisions that maximize reliability of water supply while minimizing costs for a representative household in Mexico City that uses municipal piped water, trucked water, and rainwater. We find that securing reliable water supply for IWS households is greatly assisted by installation of household storage tanks of at least 2500 L. In the case of IWS households with limited storage options, the overall cost for water supply is reduced by scheduling water deliveries on nonconsecutive days. Rainwater harvesting systems were shown to be economically viable for households with limited water supply. This study demonstrates the importance of considering the management of multiple sources and household storage infrastructure when evaluating water investments in cities with IWS.

Limited evidence of coupling between above and belowground functional traits in tropical dry forest seedlings / Evidencia limitada de acoplamiento entre rasgos funcionales por encima y por debajo del suelo en plántulas de bosque seco tropical

Abstract Introduction: Water availability is one of the main factors determining the distribution of woody species in the tropics. Although the functional mechanisms that determine the species tolerance to water deficit have been extensively studied in adult individuals, the responses of early ontogenetic stages have been less explored. Objective: To identify functional strategies and trait correlations between different seedlings' dimensions (leaf, stem, and root). We expect limited coordination between above and below-ground functional traits due to a single conservation-acquisition trade-off cannot capture the variability of functions and environmental pressures to which the root system is subjected. Methods: We measured 12 functional traits belonging to 38 seedling species in a tropical dry forest in Colombia. We explored the relationships between pairs of traits using Pearson correlations, and to obtain an integrated view of the functional traits, a principal component analysis (PCA) was performed. Results: The results showed limited evidence of linkage between above- and below-ground traits, but we did find significant correlations between traits for the continuum of conservative and acquisitive strategies. Root traits related to water and nutrient take capacity formed an orthogonal axis to the acquisitive-conservative continuum. Conclusions: Our results showed that dry forest seedlings have different functional strategies to cope with water deficit. The incorporation of root traits helps to explain new functional strategies not reported for leaf and stem traits. This study contributes to understanding the mechanisms that explain species coexistence and is particularly relevant for predicting future forest trajectories.

Resumen Introducción: La disponibilidad de agua es uno de los principales factores que determina la distribución de las especies leñosas en los trópicos. A pesar que los mecanismos funcionales que determinan la tolerancia de las especies al déficit hídrico han sido ampliamente estudiados en los individuos adultos, las respuestas de estados ontogenéticos tempranos han sido menos exploradas. Objetivo: Identificar las estrategias funcionales y las correlaciones de rasgos entre diferentes dimensiones de las plántulas (hoja, tallo y raíz). Nosotros esperamos baja coordinación entre los rasgos funcionales sobre y bajo el suelo debido a que un único trade-off conservación-adquisición de recursos, no puede capturar la variabilidad de funciones y presiones ambientales a las que están expuestas las raíces. Métodos: Medimos 12 rasgos funcionales pertenecientes a 38 plántulas en un bosque seco en Colombia. Exploramos las relaciones entre pares de rasgos usando correlaciones de Pearson, y para tener una visión integrada de los rasgos funcionales, usamos un análisis de componentes principales (ACP). Resultados: Reportamos limitada evidencia de acoplamiento entre los rasgos sobre y bajo el suelo, pero encontramos correlaciones significativas entre el continuo de estrategias conservativas y adquisitivas. Los rasgos de raíz relacionados con la capacidad de absorción de agua y nutrientes formaron un eje ortogonal al continuo adquisitivo-conservativo. Conclusiones: Nuestros resultados mostraron que las plántulas del bosque seco tienen diferentes estrategias funcionales para lidiar con el déficit hídrico. La incorporación de los rasgos de la raíz ayuda a explicar nuevas estrategias funcionales no reportadas por los rasgos de hoja y tallo. Este estudio contribuye al entendimiento de los mecanismos que explican la coexistencia de especies y es particularmente relevante para predecir las trayectorias de los bosques futuros.

Microshear bond strength of universal adhesives to enamel and dentin: an eighteen-month in vitro study / Resistência de união ao microcisalhamento de adesivos universais ao esmalte e dentina: estudo in vitro de dezoito meses

Objective: The aim of this study was to evaluate the microshear bond strength of Universal adhesives to enamel and dentin after one week and eighteen months of water storage. Material and Methods: Fragments from the buccal surfaces of 80 bovine teeth were prepared (12x5x1.0 mm) and ground to obtain flat surfaces of enamel and dentin. Samples were randomly assigned to 8 experimental groups (n=10), according to four adhesive systems (Adper Single Bond Plus/control ­ not a Universal adhesive/ASB; Ambar Universal/AUN; Prime&Bond Active/PBA and Scotchbond Universal/SBU) and two water-storage times (one week and eighteen months after sample preparations). Adhesives were applied according to the manufacturers' instructions and molds were positioned over bonded surfaces. A flowable composite was poured into the molds to fill up their internal diameter and obtain resin cylinder (1.0mm height/0.7mm internal diameter) after light-curing. Bond strength was determined using a testing machine (0.5 mm/min) and data were statistically analyzed by two-way analysis of variance (ANOVA) and the post-hoc Tukey's test (alpha=0.05). Failure patterns were analyzed for all resin cylinder tested. Results: For enamel, differences among adhesives were observed only at 18 months, in which SBU produced lower bond strength values (15.9±3.0 MPa) than the others universal adhesives (AUN: 19.3±4.8 and PBA: 21.4±2.1 MPa) (p<0.05). For dentin, there were differences among adhesives only at 7 days, with PBA showing the highest bond strength (37.4±4.9 MPa) and ASB the lowest one (19.4±3.9 MPa) (p<0.05). Enamel and dentin bond strength of all adhesives decreased significantly after 18 months and reduction percentage varied from 36.9 to 52.4 for enamel and from 35.1 to 62.8 for dentin. Adhesive and mixed failures showed high incidences. Conclusion: Results suggested that adhesives presented differences among them depending on type of hard dental tissue and evaluation time. Enamel and dentin bond strengths of control and all universal adhesives tested were not stable, decreasing at eighteen months. (AU)

Objetivo: O objetivo deste estudo foi avaliar a resistência de união ao microcisalhamento de adesivos universais ao esmalte e dentina após uma semana e dezoito meses de armazenamento em água. Material e Métodos: Fragmentos da superfície vestibular de 80 dentes bovinos foram preparados (12x5x1,0 mm) até o obtenção de superfícies planas de esmalte e dentina. As amostras foram distribuídas aleatoriamente em 8 grupos experimentais (n=10), de acordo com quatro sistemas adesivos (Adper Single Bond Plus / controle - não universal; Ambar Universal; Prime & Bond Active e Scotchbond Universal) e dois tempos de armazenamento em água (uma semana e dezoito meses após o preparo das amostras). Os adesivos foram aplicados de acordo com as instruções dos fabricantes e as matrizes foram posicionadas sobre as superfícies aderidas. Um compósito fluido foi aplicado nas matrizes para preencher seu diâmetro interno e obter o cilindro do compósito por fotopolimeração (1,0 mm de altura / 0,7 mm de diâmetro interno). A resistência de união foi determinada em uma máquina universal de ensaios (0,5mm/min). Os dados foram analisados estatisticamente pela análise de variância dois fatores (ANOVA) e teste de Tukey (alfa 0,05). Resultados: Para o esmalte, foram obtidas diferenças apenas aos 18 meses, em que Scotchbond Universal produziu menor média de resistência de união do que os demais adesivos universais. Para dentina, houve diferenças entre os adesivos apenas aos 7 dias, com o Prime & Bond Active apresentando a maior resistência de união e o Adper Single Bond Plus a menor. Os resultados sugeriram que os adesivos apresentaram diferenças entre si dependendo do substrato e do tempo de avaliação. Conclusão: As resistências de união em esmalte e dentina do controle e de todos os adesivos universais testados não foram estáveis, diminuindo aos dezoito meses (AU)

A qualitative study of community perspectives surrounding cleaning practices in the context of Zika prevention in El Salvador: implications for community-based Aedes aegypti control.

BACKGROUND: In El Salvador, Aedes aegypti mosquitoes transmitting Zika and other arboviruses use water storage containers as important oviposition sites. Promotion of water storage container cleaning is a key element of prevention programs. We explored community perceptions surrounding cleaning practices among pregnant women, male partners of pregnant women, and women likely to become pregnant. METHODS: Researchers conducted 11 focus groups and 12 in-depth interviews which included individual elicitations of Zika prevention measures practiced in the community. Focus group participants rated 18 images depicting Zika-related behaviors according to effectiveness and feasibility in the community context, discussed influencing determinants, voted on community intentions to perform prevention behaviors, and performed washbasin cleaning simulations. In-depth interviews with male partners of pregnant women used projective techniques with images to explore their perceptions on a subset of Zika prevention behaviors. RESULTS: General cleaning of the home, to ensure a healthy environment, was a strong community norm. In this context, participants gave water storage container cleaning a high rating, for both its effectiveness and feasibility. Participants were convinced that they cleaned their water storage containers effectively against Zika, but their actual skills were inadequate to destroy Aedes aegypti eggs. A further constraint was the schedule of water availability. Even during pregnancy, male partners rarely cleaned water storage containers because water became available in homes when they were at work. Furthermore, prevailing gender norms did not foster male participation in domestic cleaning activities. Despite these factors, many men were willing to provide substantial support with cleaning when their partners were pregnant, in order to protect their family. CONCLUSIONS: Behavior change programs for the prevention of Zika and other arboviruses need to improve community members' mosquito egg destruction skills rather than perpetuate the promotion of non-specific cleaning in and around the home as effective. Egg elimination must be clearly identified as the objective of water storage container maintenance and programs should highlight the effective techniques to achieve this goal. In addition, programs must build the skills of family members who support pregnant women to maintain the frequency of effective egg destruction in all water storage containers of the home.

The challenge of achieving safely managed drinking water supply on San Cristobal island, Galápagos.

Achievement of United Nations Sustainable Development Goal 6.1 centers on the availability of a safely managed drinking water source for all. However, meeting the criteria for this goal is challenging on island systems and elsewhere with limited freshwater supplies. We measured microbial and chemical water quality over three years on San Cristobal Island, Galapagos, an island with limited freshwater supply, necessitating use of cisterns or roof tanks to ensure water availability in households. Our results showed that the municipal water treatment plants generally produced high quality drinking water but detection of Escherichia coli in 2-30% of post-treatment distribution samples suggests contamination and/or regrowth during distribution and storage. Linear regression revealed a modest, negative relationship between residual chlorine and microbial concentrations in drinking water samples, while 24-h antecedent rainfall only slightly increased microbial counts. Taken together, our results underscore the challenge of providing a safely managed drinking water source where limited freshwater quantities result in intermittent flow and require storage at the household level. Efforts to meet sustainable development goals for island systems will likely need to consider water availability for any treatment technologies or programs aimed at meeting water quality goals.

Potential microbial transmission pathways in rural communities using multiple alternative water sources in semi-arid Brazil.

BACKGROUND: Water scarcity combined with high incidences of diarrhoeal disease amongst many rural communities, suggests that the provision of 'safe' water supplies remains a challenge. Subsequent reliance on multi-source water supplies means that microbial transmission pathways may be numerous and complex. OBJECTIVES: This study aimed to identify and elucidate water supply issues and potential microbial transmission pathways at the household level in rural communities in semi-arid Brazil. METHODS: Community and sanitary surveys were applied to 99 households from 10 communities located in four municipalities of Paraiba State, Brazil. Moreover, physicochemical and microbial parameters were investigated throughout the water supply chain. RESULTS: High levels of faecal indicator organisms (FIO) were detected in water from Water Storage Reservoirs (WSR) and from in-house Drinking Water Storage Containers (DWSC). A decrease in microbial water quality was observed between water stored within WSR's and DWSC's, suggesting potential cross-contamination at the household level. Several common practices were observed among rural residents, such as the use of collection buckets left unprotected outside on the ground, that may have also contributed to the observed decrease. Schematic diagrams illustrating the complex water supply chains and potential microbial transmission pathways were developed to facilitate identification of effective intervention strategies. DISCUSSION: Decreases in water supply quality were found to be predominantly caused by cross-contamination within the domestic environment due to several factors, including, a lack of awareness and knowledge of 'safe' collection, handling and storage of water, as well as inadequate sanitation services and/or unhygienic practices. In order to improve public health in such communities, more effort should be directed towards education and training of all stakeholders involved in the water supply chain. This would, certainly, support the successful implementation of further WASH interventions, consequently increasing the likelihood of achieving reduction of excreta-borne diseases.

Using GRACE to quantify the depletion of terrestrial water storage in Northeastern Brazil: The Urucuia Aquifer System.

Covering a plateau area of approximately 125,000 km2, the Urucuia Aquifer System (UAS) represents a national strategic water resource in the drought-stricken Northeastern part of Brazil. Variations in terrestrial water storage (TWS) extracted using a three-model-ensemble from the Gravity Recovery and Climate Experiment (GRACE) mission showed a negative balance equal to water stress. Monthly GRACE-derived water storage changes from 2002 to 2014 were compared with those derived from an independent hydrologic water balance of the region using in situ measurements and estimated evapotranspiration rates. Trend analyses revealed a TWS depletion rate of 6.5 ±â€¯2.6 mm yr-1, but no significant decline in precipitation as observed from available data records. Water storage depletion was found to be driven by anthropogenic impacts rather than by natural climatic variability. The obtained results demonstrate that GRACE is able to adequately capture water storage changes at the subregional scale, particularly during dry seasons.

A Structure Shaped by Fire, but Also Water: Ecological Consequences of the Variability in Bark Properties Across 31 Species From the Brazilian Cerrado.

Bark is a structure involved in multiple physiological functions, but which has been traditionally associated with protection against fire. Thus, little is known about how the morpho-anatomical variations of this structure are related to different ecological pressures, especially in tropical savanna species, which are commonly subjected to frequent fire and drought events. Here we evaluated how the structural and functional variations of bark are related to the processes of resilience and resistance to fire, as well as transport and storage of water in 31 native species from the Brazilian Cerrado. Because of their thick bark, none of the trees analyzed were top-killed after a severe fire event. The structural and functional variations of the bark were also associated with water storage and transport, functions related to properties of the inner bark. In fact, species with a thicker and less dense inner bark were the ones that had the highest water contents in the wood, bark, and leaves. Lower bark density was also related to higher stem hydraulic conductivity, carbon assimilation, and growth. Overall, we provide strong evidence that in addition to protection from fire, the relative investment in bark also reflects different strategies of water use and conservation among many Cerrado tree species.

Inorganic and organic contaminants in drinking water stored in polyethylene cisterns.

This work evaluated the presence of contaminants in stored rainwater in 36 polyethylene tanks installed in two rural communities of the semiarid of Bahia, Brazil. Carbonyl compounds were analyzed by High Performance Liquid Chromatography (HPLC-UV), BTEX (Benzene, Toluene, Ethylbenzene and Xylenes) by gas chromatoghaphy (GC-FID), and trace elements by inductively coupled plasma optical emission spectrometry (ICP-OES). Seven carbonyl compounds were quantified including acrolein (<3-115 µg L-1), which is considered a potent mutagenic agent, above the potability limit in 75% of the cases. Trace elements such as copper, zinc, barium, aluminum and lead, more frequently found, were also quantified, and lead (<0,56-99 µg L-1) was above the tolerable limit for drinking water of 10 µg L-1 in 73% of the cases. The results show that the stored water in polyethylene cisterns in the Brazilian semiarid region does not present satisfactory conditions for human consumption.

Water extraction and implications on soil moisture sensor placement in the root zone of banana

The knowledge on spatial and temporal variations of soil water storage in the root zone of crops is essential to guide the studies to determine soil water balance, verify the effective zone of water extraction in the soil and indicate the correct region for the management of water, fertilizers and pesticides. The objectives of this study were: (i) to indicate the zones of highest root activity for banana in different development stages; (ii) to determine, inside the zone of highest root activity, the adequate position for the installation of soil moisture sensors. A 5.0 m3 drainage lysimeter was installed in the center of an experimental area of 320 m2. Water extraction was quantified inside the lysimeter using a 72 TDR probe. The concept of time stability was applied to indicate the position for sensor installation within the limits of effective water extraction. There are two patterns of water extraction distribution during the development of banana and the point of installation of sensors for irrigation management inside the zone of highest root activity is not constant along the crop development.

Water extraction and implications on soil moisture sensor placement in the root zone of banana

The knowledge on spatial and temporal variations of soil water storage in the root zone of crops is essential to guide the studies to determine soil water balance, verify the effective zone of water extraction in the soil and indicate the correct region for the management of water, fertilizers and pesticides. The objectives of this study were: (i) to indicate the zones of highest root activity for banana in different development stages; (ii) to determine, inside the zone of highest root activity, the adequate position for the installation of soil moisture sensors. A 5.0 m3 drainage lysimeter was installed in the center of an experimental area of 320 m2. Water extraction was quantified inside the lysimeter using a 72 TDR probe. The concept of time stability was applied to indicate the position for sensor installation within the limits of effective water extraction. There are two patterns of water extraction distribution during the development of banana and the point of installation of sensors for irrigation management inside the zone of highest root activity is not constant along the crop development.(AU)

Effect of storage time and chlorhexidine addition on the mechanical properties of glass ionomer cements

Aims: To evaluate the effect of the chlorhexidine (CHX) incorporation and the storage time on the mechanical properties of glass ionomer cements (GICs). Methods: The following GICs were evaluated: Ketac Molar Easymix (KM), Vidrion R (VR) and Vitromolar (VM), containing or not CHX. GIC liquid was modified by adding 1.25 % CHX digluconate and then manipulated with the power and placed into the stainless steel cylindrical or bar-shaped molds. GICs specimens were stored into water for 1, 7 and 28 days. After these periods, specimens were submitted to flexural, diametral tensile and compressive strength tests, according to ISO standards. Data from mechanical tests were statistically analyzed using 2-way ANOVA and Tukey tests. Results: Overall, the storage time did not influence any of the mechanical properties of the GICs tested. In contrast, the inclusion of CHX reduced significantly these properties for all GICs tested. KM presented the highest values of compressive strength for all storage times. KM + 1.25% CHX had lower compressive strength results than KM, however, it showed similar results when compared to another GICs without CHX. Conclusions: The presence of chlorhexidine, independent of the storage time, interfered on the mechanical characteristics of GIC (AU)

Comparative bonding ability to dentin of a universal adhesive system and monomer conversion as functions of extended light curing times and storage.

OBJECTIVES: The purpose of this in vitro study was to evaluate the bonding ability and monomer conversion of a universal adhesive system applied to dentin as functions of different curing times and storage. The results were compared among a variety of commercial adhesives. MATERIALS AND METHODS: Flat superficial dentin surfaces were exposed on human molars and assigned into one of the following adhesives (n = 15): total-etch Adper Single Bond 2 (SB) and Optibond Solo Plus (OS), self-etch Optibond All in One (OA) and Clearfil SE Bond (CSE), and Scotchbond Universal Adhesive in self-etch mode (SU). The adhesives were applied following the manufacturers' instructions and cured for 10, 20, or 40s. Specimens were processed for the microtensile bond strength (µTBS) test in accordance with the non-trimming technique and tested after 24h and 2 years. The fractured specimens were classified under scanning electron microscopy (SEM). Infrared (IR) spectra were obtained and monomer conversion (%) was calculated by comparing the aliphatic-to-aromatic IR absorption peak ratio before and after polymerization (n=5). Data were analyzed by 2-way ANOVA/Tukey's tests (α = 0.05). RESULTS: At 24-h evaluation, OA and CSE presented similar bond strength means irrespective of the curing time, whereas SB and SU exhibited significantly higher means when cured for 40s as did OS when cured for 20 or 40s (p < 0.05). At 2-year evaluation, only OA exhibited significantly higher bond strength when cured for 20 and 40s (p < 0.05). When the evaluation times were compared, OA also exhibited the same bonding ability when cured for longer periods of time (20 and 40s). All of the adhesives tested exhibited significantly lower monomer conversion when photoactivated according to the manufacturers' instructions (10s). CONCLUSIONS: Higher monomer conversions obtained with longer light exposure allow only higher immediate bond strength for most of the adhesives tested. After 2-year storage, only the self-etching adhesive Optibond All-In-One exhibited the same bonding ability when cured for longer periods of time.

Effect of 180-Day Water Storage on Bonding Effectiveness of Self-Adhesive Systems to Occlusal and Proximal Dentin.

PURPOSE: This study aimed to evaluate the microshear bond strength (µSBS) values of adhesive systems to occlusal and proximal dentin submitted to water storage aging. MATERIALS AND METHODS: Occlusal and proximal dentin surfaces were obtained from 90 molars, polished with 600-grit SiC and divided according to the type of adhesive system: one total-etch and two self-etch. Starch tubing was used to perform 1 mm2 cylindrical composite resin restorations. The specimens were aged in distilled water during different storage times: 24 hours, 3 months, and 6 months (n = 10). The specimens were submitted to µSBS test. The µSBS values in MPa were subject to three-way ANOVA and post hoc Tukey test (p < 0.05). RESULTS: There was no statistical difference in the µSBS values among the storage times (p = 0.72); however, the dentin region (p < 0.01) and the adhesive system (p < 0.01) significantly affected the µSBS. The proximal surface (14.7 ± 3.3 MPa) presented higher µSBS values than the occlusal dentin (10.9 ± 4.1 MPa). The all-in-one adhesive system (GB) achieved the highest µSBS mean (17.0 ± 1.7 MPa). CONCLUSION: Both material and dentin surface factors affected the composite-dentin bond strength; however, the water storage did not influence bonding effectiveness over time.

Efeito da contaminação por saliva humana na interface adesiva: resistência de união, análise de camada híbrida e conversão de sistemas adesivos / Effect of human saliva contamination on adhesive interface: bond strength, hybrid layer analysis and conversion of adhesive systems

Este estudo teve como objetivo analisar o efeito da contaminação por saliva humana na resistência de união (RU) da interface adesiva em dentina por microtração, nas características morfológicas da camada híbrida (CH) em microscopia confocal e no grau de conversão (GC) de 2 sistemas adesivos: Adper Single bond 2 (SB) e Single Bond® Universal (SU). Cento e oitenta dentes terceiros humanos hígidos foram divididos em 12 grupos (n=10), de acordo com o sistema adesivo utilizado, a presença de saliva e o tempo de armazenagem. Após o procedimento adesivo e aplicação da resina composta Filtek Z250, os dentes foram mantidos em água destilada em estufa a 37°C por 48 horas, 6 meses ou 12 meses antes de serem seccionados em palitos (0,8mm x 0,8mm, aproximadamente) para serem levados à máquina de ensaios universal Instron para os testes de microtração. Para à análise da interface adesiva em microscopia confocal de varredura a laser para verificação e mensuração de alterações internas na interface foram utilizados 60 dentes divididos em 6 grupos (n=10) de acordo com os tempos de 48 horas, 6 meses, e 12 meses respectivamente, empregando os sistemas adesivos (SB) e (SU). O efeito da presença de saliva também foi avaliado pelo grau de conversão dos adesivos, empregando-se espectroscopia de infravermelho transformada de Fourier empregando os sistema adesivos (SB) e (SU) com incorporação de saliva humana na sua composição (n=5) com concentrações 10%, 25% e 50% em vol. Para a comparação das variáveis: RU, (GC), espessura da CH, na presença de saliva e tempo de armazenamento foram utilizados os testes de Análise de Variância a três critérios e de comparações múltiplas de Tukey (p<0,05). Os valores de RU (MPa±dp: 48horas/6meses/1ano) foram: SB (43,53 ±6,0; 40,10±3,4; 38,59±5,4); SalSB (43,09±6,2; 39,86±6,6; 37,255,8); SU (42,98±4,3; 39,30±3,6; 40,44±5,7); Sal SU (44,39±4,2; 42,26±2,5; 38,26±5,7). Os Valores médios da CH (MPa±dp: 48horas/6meses/1ano) foram: SalSB (3,59±0,8; 3,59±1,0; 2,08±1,5). SalSU (1,26±0,5; 1,73±0,8; 1,07±0,3). Os valores de GC (MPa±dp: 10%/25%/50%vol) foram: SB (85,59±3,4; 49,68±12,8; 38,56±11,8); SU (85,52±3,3; 86,27±3,5; 57,82±11,1).Conclui-se, portanto, que a contaminação por saliva humana não interferiu na RU da interface dentina/resina composta após 48 horas, 6 meses e 12 meses. A morfologia da camada hibrida foi alterada pela presença da saliva nos períodos 6 e 12 meses,. O GC dos sistemas adesivos foi afetado pela presença de saliva após a polimerização imediata. Entretanto o fator tempo foi determinante para a deformação da interface dentina/resina para ambos os sistemas adesivos.(AU)

The objective of this study was to analyze the effect of human saliva contamination on bond strength of the dentin/adhesive interface, morphology of the hybrid layer by confocal microscopy and SEM analysis and degree of conversion of 2 adhesive systems: Adper Single bond 2 (SB) and Single Bond® Universal ( SU). One hundred and eighty healthy human third teeth were divided into 12 groups (n = 10), according to the adhesive system used, the presence of saliva and the storage time. After the adhesive procedure and placement of resin composite (Filtek Z250), the teeth were stored in distilled waterat 37 ° C for 48 hours, 6 months or 12 months before being cut into sticks (0.8mm x 0.8mm, approximately) to the microtensile strength tests. For the analysis of the adhesive interface in confocal microscopy of laser scanning for verification and measurement of internal interface changes, 60 teeth were used divided into 6 groups (n = 10) according to the storage time: 48 hours, 6 months, and 12 monthsand (SB) and (SU). The effect of the presence of saliva was also evaluated by the degree of conversion of the adhesives using Fourier transform infrared spectroscopy employing adhesive (SB) and (SU) systems incorporating human saliva in its composition (n = 5) with 10%, 25% and 50% vol. For the comparison of the variables: bond strength, degree of conversion, and hybrid layer thickness in the presence of saliva and storage time, the three criteria Variance Analysis and Tukey multiple comparisons tests (p <0.05) were used. The values of bond strength (MPa ± dp: 48hours / 6meses / year) were: SB (43.53 ± 6.0, 40.10 ± 3.4, 38.59 ± 5.4); SalSB (43.09 ± 6.2, 39.86 ± 6.6, 37.255.8); SU (42.98 ± 4.3, 39.30 ± 3.6, 40.44 ± 5.7); SU salt (44.39 ± 4.2, 42.26 ± 2.5, 38.26 ± 5.7). The mean values of hybrid layer thickness (MPa ± dp: 48hours / 6meses / year) were: SalSB (3.59 ± 0.8, 3.59 ± 1.0, 2.08 ± 1.5). SalSU (1.26 ± 0.5, 1.73 ± 0.8, 1.07 ± 0.3). The values of degree of conversion (MPa ± dp: 10% / 25% / 50% vol) were: SB (85.59 ± 3.4, 49.68 ± 12.8, 38.56 ± 11.8); (85.52 ± 3.3, 86.27 ± 3.5, 57.82 ± 11.1). It was therefore concluded that human saliva contamination did not interfere on bond strength of the dentin/adhesive interface after 48 hours, 6 months and 12 months. The morphology of the hybrid layer was altered by the presence of saliva after 6 and 12 months. The degree of conversion of adhesive systems was affected by the presence of saliva immediately after polymerization. However, the time factor was determinant for the dentine/resin interface deformation for both adhesive systems.(AU)

Diagnóstico del sistema de aprovechamiento del agua lluvia en el consejo comunitario de la comunidad negra de los lagos, buenaventura / Diagnostic system rain water harvesting in the black community council community of lagos, buenaventura

Este trabajo presenta los resultados de la investigación realizada en el Consejo Comunitario de la Comunidad Negra Los Lagos (CCCN Los Lagos); la cual consistió en diagnosticar las condiciones de aprovechamiento del agua lluvia, por lo que se pudo determinar el potencial de aprovechamiento del agua lluvia en la comunidad, los tipos de techos que utilizan las viviendas, el sistema de recolección y conducción del agua lluvia, los tipos de recipientes para realizar el almacenamiento del agua lluvia. Para la identificación de los aspectos anteriores, se realizaron visitas al lugar, así como también la realización de entrevistas semiestructuradas y encuestas (anexo 1). Luego de conocer el sistema de abastecimiento del agua lluvia, se realizó análisis fisicoquímicos y microbiológicos al agua lluvia recolectada, permitiendo conocer con ello el cumplimiento o no de la normativa ambiental; además, se aplicaron análisis estadísticos para determinar correlaciones y varianzas en los resultados.

This paper presents the results of research conducted at the Community Council of the black community of Los Lagos, which was to diagnose the conditions of use of rain water, so they could determine the potential use of rain water in the community, the types of roofs used housing, the system of collection and conveyance of rain water, types of containers for storage of rain water; for the identification of the above aspects, site visits were conducted, as well as semi-structured interviews and surveys. After meeting the supply system of rain water, chemical and microbiological to rain water collected analyzes were performed, thus allowing to know or not compliance with environmental regulations; Additional statistical analyzes were applied to determine correlations and variances in the results.