Different levels of water deficit induces changes in growth pattern but not in chlorophyll fluorescence and water relations of Hancornia speciosa Gomes seedlings.

Hancornia speciosa Gomes é uma espécie conhecida popularmente no Brasil como mangabeira, cujo fruto apresenta alto valor nutricional. O conhecimento sobre a sua fisiologia é ainda escasso, principalmente no que se refere ao desenvolvimento inicial. Dessa forma, o objetivo do presente trabalho foi avaliar os efeitos de diferentes níveis de déficit hídrico sobre o padrão de crescimento, fluorescência de clorofila e relações hídricas em mudas de mangabeira. Foi utilizado um esquema fatorial (tratamentos x época de avaliação) com quatro tratamentos hídricos com base na capacidade de campo (CC) (80%, 60%, 40% e 20%), com cinco repetições. Foram avaliados a altura das plantas, número de folhas, diâmetro do caule, produção e partição de biomassa, eficiência quântica do fotossistema II (PSII), potencial hídrico (?w), teor relativo de água (TRA) e teor de carboidratos, proteínas e prolina. O déficit hídrico severo (20% CC) levou a uma redução no crescimento e alterou o padrão de partição de biomassa nas mudas. No entanto, as relações hídricas não foram significativamente afetadas, pois as mudas mantiveram altos valores de ?w e TRA, sem acúmulos significativos nos teores de solutos orgânicos quando cultivadas com 20%CC. Além do mais, a eficiência quântica do PSII não foi afetada pelos diferentes regimes hídricos, sugerindo que não houve fotoinibição devido ao estresse hídrico. A mudança no padrão de crescimento, com um incremento no aprofundamento das raízes e redução no crescimento da parte aérea parece ser a principal estratégia das mudas de H. speciosa para a manutenção da hidratação dos tecidos durante períodos de déficit hídrico.

Network assimilation methodology and sectorization of water distribution systems by graph mining and optimization algorithm

Water Distribution Networks (WDNs) play a vital importance rule in communities, ensuring well-being band supporting economic growth and productivity. The need for greater investment requires design choices will impact on the efficiency of management in the coming decades. This thesis proposes an algorithmic approach to address two related problems:(i) identify the fundamental asset of large WDNs in terms of main infrastructure;(ii) sectorize large WDNs into isolated sectors in order to respect the minimum service to be guaranteed to users. Two methodologies have been developed to meet these objectives and subsequently they were integrated to guarantee an overall process which allows to optimize the sectorized configuration of WDN taking into account the needs to integrated in a global vision the two problems (i) and (ii). With regards to the problem (i), the methodology developed introduces the concept of primary network to give an answer with a dual approach, of connecting main nodes of WDN in terms of hydraulic infrastructures (reservoirs, tanks, pumps stations) and identifying hypothetical paths with the minimal energy losses. This primary network thus identified can be used as an initial basis to design the sectors. The sectorization problem (ii) has been faced using optimization techniques by the development of a new dedicated Tabu Search algorithm able to deal with real case studies of WDNs. For this reason, three new large WDNs models have been developed in order to test the capabilities of the algorithm on different and complex real cases. The developed methodology also allows to automatically identify the deficient parts of the primary network and dynamically includes new edges in order to support a sectorized configuration of the WDN. The application of the overall algorithm to the new real case studies and to others from literature has given applicable solutions even in specific complex situations.

Data analysis and hydrological modelling of rainfall and discharge extremes along the Tione River: implications for the design of water structures

There are many natural events that can negatively affect the urban ecosystem, but weather-climate variations are certainly among the most significant. The history of settlements has been characterized by extreme events like earthquakes and floods, which repeat themselves at different times, causing extensive damage to the built heritage on a structural and urban scale. Changes in climate also alter various climatic subsystems, changing rainfall regimes and hydrological cycles, increasing the frequency and intensity of extreme precipitation events (heavy rainfall).  From an hydrological risk perspective, it is crucial to understand future events that could occur and their magnitude in order to design safer infrastructures. Unfortunately, it is not easy to understand future scenarios as the complexity of climate is enormous.  For this thesis, precipitation and discharge extremes were primarily used as data sources. It is important to underline that the two data sets are not separated: changes in rainfall regime, due to climate change, could significantly affect overflows into receiving water bodies. It is imperative that we understand and model climate change effects on water structures to support the development of adaptation strategies.   The main purpose of this thesis is to search for suitable water structures for a road located along the Tione River. Therefore, through the analysis of the area from a hydrological point of view, we aim to guarantee the safety of the infrastructure over time.   The observations made have the purpose to underline how models such as a stochastic one can improve the quality of an analysis for design purposes, and influence choices.

Flotação por ar dissolvido na clarificação de águas com baixa turbidez utilizando sulfato de alumínio e sementes de Moringa oleifera como coagulantes

This work aims to investigate the process of Dissolved air Flotation (DAF) for clarifying water samples with low turbidity using aluminum sulphate and Moringa oleifera seeds as coagulants. The experimental procedure was carried out in a bench scale flotation unit. The influences on the pre-treatment conditions (coagulant dosage and flocculation time) and flotation parameters (superficial application rate and recirculation rate) were evaluated considering the efficiency of the process. The efficiency was evaluated by determining the turbidity of the untreated and treated water samples. The results obtained showed that turbidity reduction can be obtained very efficiently by using DAF and the latter coagulant in low turbidity water. Using aluminum sulphate in pH´s 5.0 and 6.0 better efficiencies were obtained with low concentrations (15 mg/L), achieving values of 92% of turbidity reduction. In the case of use of Moringa oleifera better efficiencies of reduction of turbidity were reported when using a concentration of 50 mg/L in all range of pH´s, achieving 86% of reduction. The zeta potential was also determined, in an attempt to aid comprehension of the coagulation mechanisms involved. The coagulation mechanisms with Moringa oleifera seeds were shown to be adsorption and charge neutralization, as well as adsorption and bridging. Concerning aluminum sulphate, the predominant mechanisms are adsorption and charge neutralization and enmeshment in a precipitate. The results indicate that for low turbidity water, Moringa oleifera seeds could potentially be a viable substitute for aluminum sulphate

Expression of a plant-derived peptide harboring water-cleaning and antimicrobial activities.

Drinking water is currently a scarce world resource, the preparation of which requires complex treatments that include clarification of suspended particles and disinfection. Seed extracts of Moringa oleifera Lam., a tropical tree, have been proposed as an environment-friendly alternative, due to their traditional use for the clarification of drinking water. However, the precise nature of the active components of the extract and whether they may be produced in recombinant form are unknown. Here we show that recombinant or synthetic forms of a cationic seed polypeptide mediate efficient sedimentation of suspended mineral particles and bacteria. Unexpectedly, the polypeptide was also found to possesses a bactericidal activity capable of disinfecting heavily contaminated water. Furthermore, the polypeptide has been shown to efficiently kill several pathogenic bacteria, including antibiotic-resistant isolates of Staphylococcus, Streptococcus, and Legionella species. Thus, this polypeptide displays the unprecedented feature of combining water purification and disinfectant properties. Identification of an active principle derived from the seed extracts points to a range of potential for drinking water treatment or skin and mucosal disinfection in clinical settings.

Characterization of a plant-derived peptide displaying water clarifying and antimicrobial activities

SUMMARY Drinking water is currently a scarce world resource, the preparation of which requires complex treatments that include clarification of suspended particles and disinfection. Seed extracts of Moringa oleifera Lam., a tropical tree, have been proposed as an environment- friendly alternative, due to their traditional use for the clarification of drinking water. However, the precise nature of the active components was unknown. Here, we show that recombinant or synthetic forms of a cationic seed polypeptide mediate efficient sedimentation of suspended mineral particles and bacteria. Unexpectedly, the polypeptide was also found to possesses a bactericidal activity capable of disinfecting heavily contaminated water. Furthermore, the polypeptide has been shown to efficiently kill several pathogenic bacteria, including antibiotic-resistant isolates of Pseudomona, Streptococcus and Legionella species. Structural modeling of the peptide coupled to the functional analysis of synthetic peptide derivatives delineated distinct structural determinants for the flocculation and antibacterial activities. Our results suggest that a glutamine-rich portion of the polypeptide is involved in the sedimentation process; alternatively, the antibacterial activity depends on a amphiphilic loop. Assembly of multiple copies of this loop into a branched peptide derivative strongly enhances antibacterial activity without displaying hemolytic effect. In conclusion, this polypeptide displays the unprecedented feature of combining efficient water purification and disinfectant properties indicating different molecular mechanisms involved in each case. This work not only identified the features responsible for these activities but also provides useful information that has implications for the further development of this cationic polypeptide as a potent antibacterial agent. RESUME L'eau potable est actuellement une ressource limitée dans le monde. La production d'eau propre à la consommation exige des traitements complexes, incluant la clarification des particules en suspension ainsi que sa désinfection par des additifs chimiques. Les extraits de la graine d'un arbre tropical, Moringa oleifera, sont utilisés traditionnellement en Afrique afin de clarifier l'eau. Quoique la nature exacte des composants actifs était inconnue, on a pu mettre en évidence un polypeptide cationique contenu dans ces graines, capable de sédimenter de manière efficace des particules minérales en suspension ainsi que des bactéries. Ce travail a aussi mis en évidence que ce polypeptide a une activité bactéricide, permettant une désinfection d'eau fortement contaminée. De plus, nous avons démontré que ce polypeptide est efficace contre de nombreuses souches bactériennes pathogènes, également celles résistantes aux antibiotiques comme Pseudomonas, Streptococcus et Legionella. L'analyse de la structure moléculaire de ce polypeptide, couplée à son analyse fonctionnelle a mis en évidence deux domaines structuraux distinct, un pour l'activité de floculation et l'autre pour l'activité antibactérienne. Nos résultats suggèrent que le domaine riche en glutamine est impliqué dans le processus de sédimentation et que l'activité antimicrobienne dépend d'un domaine formant une boucle amphiphilique. En ramifiant plusieurs copies de cette boucle on a pu augmenter de manière significative l'activité antibactérienne. En conclusion, nous avons pu démontrer que ce polypeptide à la capacité unique de combiner des propriétés de purification et de désinfection de l'eau, ce qui implique des mécanismes moléculaires distincts pour ces deux activités. Ce travail a permis d'identifier les domaines du polypeptide qui sont responsables de ses activités et offre une perspective pour le développement d'un nouvel agent antimicrobien.

Caffeine As An Indicator Of Estrogenic Activity In Source Water.

Caffeine has already been used as an indicator of anthropogenic impacts, especially the ones related to the disposal of sewage in water bodies. In this work, the presence of caffeine has been correlated with the estrogenic activity of water samples measured using the BLYES assay. After testing 96 surface water samples, it was concluded that caffeine can be used to prioritize samples to be tested for estrogenic activity in water quality programs evaluating emerging contaminants with endocrine disruptor activity.

Environmental Controls In The Water Use Patterns Of A Tropical Cloud Forest Tree Species, Drimys Brasiliensis (winteraceae).

Trees from tropical montane cloud forest (TMCF) display very dynamic patterns of water use. They are capable of downwards water transport towards the soil during leaf-wetting events, likely a consequence of foliar water uptake (FWU), as well as high rates of night-time transpiration (Enight) during drier nights. These two processes might represent important sources of water losses and gains to the plant, but little is known about the environmental factors controlling these water fluxes. We evaluated how contrasting atmospheric and soil water conditions control diurnal, nocturnal and seasonal dynamics of sap flow in Drimys brasiliensis (Miers), a common Neotropical cloud forest species. We monitored the seasonal variation of soil water content, micrometeorological conditions and sap flow of D. brasiliensis trees in the field during wet and dry seasons. We also conducted a greenhouse experiment exposing D. brasiliensis saplings under contrasting soil water conditions to deuterium-labelled fog water. We found that during the night D. brasiliensis possesses heightened stomatal sensitivity to soil drought and vapour pressure deficit, which reduces night-time water loss. Leaf-wetting events had a strong suppressive effect on tree transpiration (E). Foliar water uptake increased in magnitude with drier soil and during longer leaf-wetting events. The difference between diurnal and nocturnal stomatal behaviour in D. brasiliensis could be attributed to an optimization of carbon gain when leaves are dry, as well as minimization of nocturnal water loss. The leaf-wetting events on the other hand seem important to D. brasiliensis water balance, especially during soil droughts, both by suppressing tree transpiration (E) and as a small additional water supply through FWU. Our results suggest that decreases in leaf-wetting events in TMCF might increase D. brasiliensis water loss and decrease its water gains, which could compromise its ecophysiological performance and survival during dry periods.

Fluoride Concentrations In The Water Of Maringá, Brazil, Considering The Benefit/risk Balance Of Caries And Fluorosis.

Current Brazilian law regarding water fluoridation classification is dichotomous with respect to the risks of and benefits for oral diseases, and fluoride (F) concentrations less than 0.6 or above 0.8 mg F/L are considered outside the normal limits. Thus, the law does not consider that both caries and fluorosis are dependent on the dosage and duration of fluoride exposure because they are both chronic diseases. Therefore, this study evaluated the quality of water fluoridation in Maringá, PR, Brazil, considering a new classification for the concentration of F in water the supply, based on the anticaries benefit and risk of fluorosis (CECOL/USP, 2011). Water samples (n = 325) were collected monthly over one year from 28 distribution water networks: 20 from treatment plants and 8 from artesian wells. F concentrations were determined using a specific ion electrode. The average F concentration was 0.77 mg F/L (ppm F), ranging from 0.44 to 1.22 mg F/L. Considering all of the water samples analyzed, 83.7% of them presented from 0.55 to 0.84 mg F/L, and according to the new classification used, they would provide maximum anticaries benefit with a low risk of fluorosis. This percentage was lower (75.4%) in the water samples supplied from artesian wells than from those distributed by the treatment plant (86%). In conclusion, based on the new classification of water F concentrations, the quality of water fluoridation in Maringá is adequate and is within the range of the best balance between risk and benefit.

Effect of cement type and water storage time on the push-out bond strength of a glass fiber post

This study investigated the effects of the cement type and the water storage time on the push-out bond strength of a glass fiber post. Glass fiber posts (Fibrekor, Jeneric Pentron) were luted to post spaces using a self-cured resin cement (C&B Cement [CB]), a glass ionomer cement (Ketac Cem [KC]) or a resin-modified glass ionomer cement (GC FujiCEM [FC]) according to the manufacturers’ instructions. For each luting agent, the specimens were exposed to one of the following water storage times (n=5): 1 day (T1), 7 days (T7), 90 days (T90) and 180 days (T180). Push-out tests were performed after the storage times. Control specimens were not exposed to water storage, but subjected to the push-out test 10 min after post cementation. Data (in MPa) were analyzed by Kruskal-Wallis and Dunn`s test (α=0.05). Cement type and water storage time had a significant effect (p<0.05) on the push-out bond strength. CB showed significantly higher values of retention (p<0.05) than KC and FC, irrespective of the water storage time. Water storage increased significantly the push-out bond strength in T7 and T90, regardless of the cement type (p<0.05). The results showed that fiber posts luted to post spaces with the self-cured resin cement exhibited the best bonding performance throughout the 180-day water storage period. All cements exhibited a tendency to increase the bond strength after 7 and 90 days of water storage, decreasing thereafter.

Detection of Giardia and Cryptosporidium cysts/oocysts in watersheds and drinking water sources in Brazil urban areas

The protozoan parasites Giardia and Cryptosporidium have been described as important waterbone disease pathogens, and are associated with severe gastrointestinal illnesses. The objective of this paper was to investigate the presence of Giardia cysts and Cryptosporidium oocysts in sample from wtershed catchments and treated water sources. A total of 25 water samples were collected and examined according to the EPA - Method 1623, 2005, consisting of 12 from drinking water and 13 from raw water. Positive samples from raw water for Giardia cysts and Cryptosporidium oocysts were 46.1 and 7.6%, respectively. In finished water, positive samples were 41.7 per centfor Giardia cysts and 25 per cent for Cryptosporidium oocysts. Concentrations of Giardia cysts found in raw water samples ranged from "not detected" to 0.1oocysts/L, whereas concentrations of Cryptosporidium oocystsranged from "not detected" to 0.1 oocysts/L. In finished water, Giardia concentrations ranged from "not detected" to 0.06 cysts/L, and Cryptosporidium oocysts were not high in the samples analyzed. Nevertheless, the results of this study highlight the need to monitor these organisms in both raw and drinking water.

Combined Monte Carlo and quantum mechanics study of the solvatochromism of phenol in water. The origin of the blue shift of the lowest pi-pi* transition

A combined and sequential use of Monte Carlo simulations and quantum mechanical calculations is made to analyze the spectral shift of the lowest pi-pi* transition of phenol in water. The solute polarization is included using electrostatic embedded calculations at the MP2/aug-cc-pVDZ level giving a dipole moment of 2.25 D, corresponding to an increase of 76% compared to the calculated gas-phase value. Using statistically uncorrelated configurations sampled from the MC simulation,first-principle size-extensive calculations are performed to obtain the solvatochromic shift. Analysis is then made of the origin of the blue shift. Results both at the optimized geometry and in room-temperature liquid water show that hydrogen bonds of water with phenol promote a red shift when phenol is the proton-donor and a blue shift when phenol is the proton-acceptor. In the case of the optimized clusters the calculated shifts are in very good agreement with results obtained from mass-selected free jet expansion experiments. In the liquid case the contribution of the solute-solvent hydrogen bonds partially cancels and the total shift obtained is dominated by the contribution of the outer solvent water molecules. Our best result, including both inner and outer water molecules, is 570 +/- 35 cm(-1), in very good agreement with the small experimental shift of 460 cm(-1) for the absorption maximum.

Influence of aggregates grading and water/cement ratio in workability and hardened properties of mortars

Mortar is the material responsible for the distribution of stresses in masonry structures. The knowledge about the fresh and hardened properties of mortar is fundamental to ensure a good performance of masonry walls. Water/cement ratio and aggregates grading are among several variables that influence physical and mechanical behaviour of mortars. An experimental program is presented in order to evaluate the influence of aggregates grading and water/cement ratio in workability and hardened properties of mortars. Eighteen compositions of mortar are prepared using three relations cement:lime:sand, two types of sand and three water/cement ratios. Specimens are analyzed through flow table test, compressive and flexural strength tests. Results indicate that the increase of water/cement ratio reduces the values of hardened properties and increases the workability. Besides, sands grading has no influence in compressive strength. On the other hand, significant differences in deformation capacity of mortars were verified with the variation of the type of sand. Finally, some correlations are presented among hardened properties and the compressive strength. (C) 2010 Elsevier Ltd. All rights reserved.

Study of the water retention properties of a tropical soil

Some peculiarities of water retention in a tropical lateritic soil of clayey nature are presented and discussed. The typical soil microstructure is shown through thin-layer plates emphasizing soil microaggregation and pore distribution and their repercussion on the soil-water retention curve and on hysteresis. It is shown that the clayey soil has a behavior that to a large extent resembles sandy soil, which is characterized by the relatively high saturated hydraulic conductivity, low air-entry value, and small suction range at which water drainage takes place. The severe weathering processes that originated this soil have produced an altered soil that seems to be homogeneous in terms of physical indices, hydraulic conductivity, and soil-water retention characteristics, up to 4.5 m in depth.

Identification of new ozonation disinfection byproducts of 17 beta-estradiol and estrone in water

Estrogens are a class of micro-pollutants found in water at low concentrations (in the ng L(-1) range), but often sufficient to exert estrogenic effects due to their high estrogenic potency. Disinfection of waters containing estrogens through oxidative processes has been shown to lead to the formation of disinfection byproducts, which may also be estrogenic. The present work investigates the formation of disinfection byproducts of 17 beta-estradiol (E2) and estrone (E1) in the treatment of water with ozone. Experiments have been carried out at two different concentrations of the estrogens in ground water (100 ng L(-1) and 100 mu g L(-1)) and at varying ozone dosages (0-30 mg L(-1)). Detection of the estrogens and their disinfection byproducts in the water samples has been performed by means of ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with a triple quadrupole (QqQ) and a quadrupole-time of flight (QqTOF) instrument. Both E2 and El have been found to form two main byproducts, with molecular mass (MM) 288 and 278 in the case of E2, and 286 and 276 in the case of El, following presumably the same reaction pathways. The E2 byproduct with MM 288 has been identified as 10epsilon-17beta-dihydroxy-1,4-estradieno-3-one (DEO), in agreement with previously published results. The molecular structures and the formation pathways of the other three newly identified byproducts have been suggested. These byproducts have been found to be formed at both high and low concentrations of the estrogens and to be persistent even after application of high ozone dosages. (C) 2011 Elsevier Ltd. All rights reserved.