A Topological Index is a numerical value that allows obtain information of a determined discrete structure associated with the invariants of a graph. The topological indices based on the degrees of vertices and edges have been used for more than 40 years. Among them, it is known that several are useful in the field of chemistry research. Probably, the best-known descriptor is the Randic connectivity index (R) . There are several research works on this molecular descriptor (see, for example, , , ,  and their references). For many years, scientists tried to enhance the predictive power ofthe Randic Index. This led tothe introduction of a large number of topological descriptors correlated with the original Randic Index.
Research was done with the objective of evaluating thequalityofthewater supplied tothe potable water system in Hidalgo Del Parral, which comes from two main supply sources: wells from Valle del Verano, which provide watertothe east side ofthe city, and theWater Treatment Plant, which receives water from different mines and supplies the west side ofthe city. When this plant is overcome on its capacity of treatment, a part ofthewater from the mines is fed directly tothe northwest part ofthe city. The metals lead (Pb), chromium (Cr), cadmium (Cd), zinc (Zn), and arsenic (As) were analyzed by atomic absorption (AA) technique, based in the United States Environmental Protection Agency (EPA) Method 7000B (Revision 2, February 2007). The digestion process was done according tothe guidelines established in Method NMX-AA-051- SCFI-2001, Analysis ofWater-Determination of Metals by Atomic Absorption, developed by the National Standardization Technical Committee for Environmental Protection (Mexico). The samples were collected from the following points: 13 wells and 2 re-pumping stations of Valle del Verano, the inlet and outlet oftheWater Treatment Plant and domestic faucets. The east side ofthe city, supplied by the wells of El Verano, is metal-pollution free. Thewater that comes from the mines contains high concentrations of As, Zn, Cd and Pb, with levels that can get to 0.12, 32.6, 0.26 and 3.5 mg/L, respectively. This water pollution generated by mining can be
The extent ofthe human activities that influence the environment has increased dramatically during the past few decades; terrestrial ecosystems, freshwater and marine environments and the atmosphere are all affected. Large-scale mining and fossil fuel burning have started to interfere measurably with natural hydrogeochemical cycles, resulting in a new generation of environmental problems. The scale of socio-economic activities, urbanisation, industrial operations and agricultural production, has reached the point where, in addition to interfering with natural processes within the same watershed, they also have a world-wide impact on water resources. As a result, very complex inter-relationships between socio-economic factors and natural hydrological and ecological conditions have developed. A pressing need has emerged for comprehensive and accurate assessments of trends in waterquality, in order to raise awareness ofthe urgent need to address the consequences of present and future threats of contamination and to provide a basis for action at all levels. Reliable monitoring data are the indispensable basis for such assessments.
Formation of trihalomethanes is shown to depend strongly on sev- eral environmental and/or operational water treatment plant vari- ables monitored during the disinfection processes. It has been concluded that trihalomethane formation takes place predominantly at three distinct locations ofwater treatment plants, i.e. after the ﬁ rst pre-chlorination stage, after the carbon ﬁ ltration stage – proba- bly due to desorption of already retained trihalomethanes – and after the post-chlorination stage. This formation also strongly de- pends on thequalityof incoming raw water. One ofthe most impor- tant variables to be monitored in water treatment plants for trihalomethane formation predictions resulted to be input water tem- peratures at the beginning ofthe disinfection process and inside the plant. Some other variables associated tothe organic matter quality, such as water oxidability and water conductivity resulted to be also important, as well as prechlorination, especially for the nonlinear models. Carbon ﬁ lter aging, water turbidity after carbon ﬁ lters, as well as the amount of input well water, UV absorbance, total organic carbon concentrations (the latter two after carbon ﬁ lters) and post- chlorination variables were also con ﬁ rmed to be important in both linear and nonlinear models. General improvement for external vali- dation predictions for the concentration of chloroform and bromoform was achieved with the inclusion of these new variables and with the use of nonlinear modeling methods, with prediction er- rors decreasing up to 10%, in comparison to previous application of linear modeling methods. Total trihalomethane concentration was the best predicted variable, followed by concentrations of mixed bromo – chloro trihalomethanes and chloroform. Bromoform concen- tration was still the worst predicted parameter, probably (at least in part) due to a lower precision of its reference values. Results obtained by K-PLS and SVR methods con ﬁ rmed the presence of nonlinear interactions among the operational variables, and the vi- sualization of kernel transformations proved to be especially useful for this purpose.
Soil salinization is a complex process resulting from the interaction of several factors, mainly qualityofwater used for irrigation, which deteriorates by aquifer overexploitation, and changes in rainfall patterns and aquifer recharge related to climate change. The purpose of this paper is to present a method to assess the variations of groundwater quality, to compare its suitability for irrigation and to decipher the pos- sible causes of soil salinity in Tierra Nueva, San Luis Potosí, Mexico. To assess salinization related to irrigation waterquality, dissolved anions and cations were measured in surface and groundwater samples; the most widely used waterquality indices to evaluate potential salinity risk of soils are Residual Sodium Carbonate (RSC) and Sodium Adsorption Ratio (SAR). In view ofthe limited number and uncertainty of using only two indices, in the present work a novel waterquality assessment was applied for the first time by statistically combining eight individual quality indices: (RSC), (SAR), percentage of sodium (%Na), Kelley ratio (KR), permeability index (PI), soluble sodium percentage (SSP), magnesium adsorption ratio (MAR) and cation ratio of structural sta- bility (CROSS). A factorial variance analysis and principal component analysis of these eight indices were performed to identify linearity and maximum variance. All irrigation water tests show dissolved ions that can easily precipitate as indicated by PI. In cropland, %Na, SSP, RSC, KR and PI had values unsuitable for irrigation, while RAS, CROSS and MAR values are within suitable levels. The main mechanism of soil salinization seems to be the cation exchange of Ca 2+ to Na + in the waters,
Water is a natural resource of indispensable usefulness to society as a whole. However, it is very limited, considering its use for human consumption. Clean fresh water that is suitable and of adequate quantity is of vital importance for the survival of all living organisms, as well as for the proper functioning of ecosystems, communities and economies (ANA, 2013. p. 18). However, thequalityofwater resources worldwide is under increasing threat, as human populations are growing and industrial and agricultural activities are expanding, in a scenario in which climate changes can cause major changes in the hydrological cycle. Low qualitywater endangers human health and ecosystems, reduces the availability of drinking water and resources for other purposes, limits economic productivity, and reduces the opportunities for development.
ity of pasture silages (Ibáñez and Alomar, 2008; Restaino et al., 2009), as well as dried and fresh pastures (Cozzolino and Labandera, 2002; Alomar et al., 2009; Burns et al., 2013; Lobos-Ortega et al., 2013; Moscoso and Balocchi, 2016). It has also been used to evaluate how forage sample preparation affects nutrient composition analysis (Alomar et al., 2003), green forage intake and digestibility in ruminants (Decruyenaere et al., 2009), and water-soluble carbohydrates (WSC) in stolon samples of white clover (Inostroza et al., 2017). NIRS has also been used to characterize and quantify isoflavones and phenolic acid contents in red and white clover (Krähmer et al., 2013). Although NIRS is a quick and relatively low-cost technology, prediction equations for assessing nutritional quality have mostly been developed using leave-one-out cross validation (Garcia and Cozzolino, 2006; Ibáñez and Alomar, 2008; Alomar et al., 2009; Restaino et al., 2009; Burns et al., 2013). These equations do not typically utilize a independent test set to generate a robust model to predict an unknown pasture sample.
At the beginning ofthe 20th century, Escherich noted that harmless, easily cultivated bacteria occurred in faeces. The organism was suggested for use as an indicator ofthe presence of faeces from warm-blooded animals in water. The practice of using Bacillus coli (later named Escherichia coli) as a measure ofwaterquality was adopted, and, over the years, it was used in many forms, dependent on the practical methodology available. Coliforms, faecal coliforms, and E. coli were measured, respectively, over time as new specific methods became available. The measurement of E. coli in water served as evidence ofthe presence of faeces and even as a guide to how much faecal contamination was present. This approach appeared to work, because it was applied to waters near relatively small urban centres with poor infrastructure, little water treatment, and populations with little mobility. However, this approach to measuring waterquality has been shown to have many inadequacies in identifying public health risk, no doubt related to extending its practical use to unintended applications that have never been validated.
Temperature distribution is fundamental and crucial to understanding the performance and functioning of reservoir ecosystems (Kimmel et al. 1990). From a management point of view, it is usually preferable to practice selective withdrawal. The effects ofwater withdrawal have been found to be important in determining thermal stratification in reservoirs (Martin & Arneson 1978; Ford 1990). Surface withdrawal generally dissipates heat because the heated water layer is directly removed, and cooler, denser hypolimnetic water remains. In contrast, bottom withdrawal tends to store heat because removing cool hypolimnetic water results in an expansion ofthe epilimnion layer heated by solar radiation (Kennedy 1999). In addition, selectively releasing hypolimnetic water can lead to warming ofthe hypolimnion, and a decrease in the thermal stability ofthewater column. Decreased stability can promote vertical entrainment of nutrients in the epilimnion (Effler et al. 1986). From a waterquality point of view, selective withdrawal of hypolimnetic water is better because it can increase the net export of phosphorus from anoxic reservoirs (Martin & Arneson 1978). A shortened hypolimnetic residence time could also reduce the potential for the development of anaerobic conditions, thereby reducing phosphorus release even further (Cooke et al. 1993). Indicator factors such as nutrient availability are important for determining phytoplankton distribution (Cottingham et al. 1998; Vrede et al. 1999).
The rheological behaviour of doughs was studied using a Thermo Scientific HaakeRheoStress 1 controlled strain rheometer (Thermo Fisher Scientific, Schwerte, Germany) and a Phoenix II P1- C25P water bath that controlled analysis temperature (set at 25ºC). The rheometer was equipped with parallel-plate geometry (60-mm diameter titanium serrated plate-PP60 Ti) with a 3-mm gap. After adjustment tothe 3-mm gap, the excess dough was removed and vaseline oil (Panreac, Panreac Química SA, Castellar del Vallés, Spain) was applied to cover the exposed sample surface. During the oscillatory tests, the dough was left to rest for 800 seconds before measuring. First, a strain sweep test was performed in duplicate at 25ºC with a stress range of 0.1–100 Pa at a constant frequency of 1 Hz to identify the linear viscoelastic region (LVR). On the basis ofthe results obtained, a stress value included in the linear viscoelastic region (3 to 20 Pa) was used in a frequency sweep test at 25ºC with a frequency range of 10–0.1 Hz. Values of elastic modulus (G’ [Pa]), viscous modulus (G’’ [Pa]), complex modulus (G*) (G’+i·G”) and tangent delta (Tan δ) (G’’/G’) were obtained for different frequency values (ω [Hz]) and analysed for1 Hz (Dobraszczyk and Morgenstern, 2003). Samples were analysed in duplicate. Cookie properties
Abstract: The brachyuran crabs are iteroparous species which present a high diversification of reproduction patterns, which may have evolved as a species-specific response to environmental conditions. Tropical spe- cies commonly present a year-round reproduction due to stable environment conditions. Goniopsis cruentata is a crab species widely distributed along the Western Atlantic, inhabiting practically every microhabitat in the mangrove ecosystem. The aim ofthe present study is to determine the breeding period ofthe crab Goniopsis cruentata in Northeastern Brazil and also to evaluate the influence ofwater salinity, rainfall and air and water temperature on it. A total of 71 ovigerous females, captured from August-2007 to July-2008, were used to assess the breeding period of this species. It was analyzed by the monthly proportion of ovigerous females. A correla- tion was applied to verify the influence ofthe abiotic factors on the breeding period. The present population bred seasonal-continuously with peaks in the dry period, which was not associated with monthly variations of salinity, rainfall and air and water temperatures. Therefore, according to statistical analyses, our hypothesis was refuted. However, breeding was intensified in the dry period, when salinity and temperatures were higher and rainfall was lower. We conclude that, even though breeding is not related to monthly variation of environmental factors, it occurs in periods of higher salinity and temperatures and lower rainfall. Rev. Biol. Trop. 61 (1): 29-38. Epub 2013 March 01.
We undertook a population-based cross sectional study with type 2 diabetes patients aged 55 years and older, who lived in southeastern Mexico City. Participants were selected by random sampling from the listing of diabetic patients kept by the IMSS Family Medicine Units issued by the IMSS Epidemiology Surveillance System. We estimated the sample size by considering the number of subjects needed to prove thestudy hypotheses about the relationships between social support and qualityof life, depressive symptoms and fasting glucose levels. A representative sample of 705 individuals was used; and all participants signed informed consent forms. Information was collected from two sources: a questionnaire purposely designed for this study and
Abstract - Results are presented on the hot water prehydrolysis of sugar cane bagasse for obtaining ethanol by fermentation. The experimental study consisted ofthe determination ofthe effect of temperature and time of prehydrolysis on the extraction of hemicelluloses, with the objective of selecting the best operating conditions that lead to increased yield of extraction with a low formation of inhibitors. Thestudy, carried out in a pilot plant scale rotational digester, using a 3 2 experimental design at temperatures of 150-190°C and
PCA was applied tothe normalized data to compare the compositional patterns between the analysed water samples and to identify the factors that in- fluence each one. Results of PCA are summarized in Table 3. There are several criteria to identify the number of PCs to be retained in order to understand the underlying data structure (Chen et al. 2007). In the present study, all the PCs with eigenvalues equal to or greater than 1.0 were used. Thus, four PCs with eigenvalues > 1 were retained, explaining the 93 % ofthe total variance in thewaterquality data set. The first PC (PC1) accounting for 59.65 % oftheto- tal variance, had positive loadings for WT, EC, TDS, HCO 3 , SO 4 , Cl, Na, K, Ca, Mg, F, T-Hard, T-Alk, and RAS. This PC can be related to natural sources ofthe ionic groups of salts in the basin ofthe reservoir from inflows, soil weathering and runoff, so this PC was defined as the “mineral” component.
For the normal life and health ofthe population of each country becomes important at the present time, thequality and ecological assessment ofwater. Water is essential for normal physiological processes ofthe body. Due tothe need to identify specific physico-chemical parameters ofwater and to carry out a comprehensive assessment ofthe state of drinking water in Absheron region in Azerbaijan, as research object was chosen the Ceyranbatan reservoir. Thestudy was conducted to evaluate the chemical composition, as well as its compliance with drinking waterquality standards.
Soil solids, comprising inorganic and organic components, form the matrix or the body of most soils. This matrix, or the visible part ofthe soil, is the storehouse ofwater and nutrient elements (e.g., N, P, K, Ca, Mg, Zn, Cu, etc.). It is also the site of most processes that govern soils buffering and filtering capacity, and life support capability. The buffering capacity ofthe soil refers to its ability to withstand or to adapt to sudden perturbations such as in soil reaction (i.e., pH). The filtering capacity refers to soil’s ability to remove pollutants (e.g., pathogens or chemicals including heavy metals) out ofthewater percolating through the soil by denaturing pollutants or mechanical sieving of suspended particles. Both buffering and filtering capacities depend on soil’s reactivity. The latter refers to chemical, physical, and biological reactions in soil and depends on its nature (e.g., relative proportion ofthe inorganic and organic components, coarse or fine size, small or large surface area, and low or high charge density). Soil quality is determined by these and other properties of soil solids, which in turn moderate the soil’s ability to support plant and animal life. Soil’s life support capability depends on processes that govern productivity, elemental cycling, and environment quality (see Chapter 1).
Abstract. Linked Open Data has been one ofthe most widely used online data publishing methods in recent years. This growth means that thequalityof this data is required for the beneﬁt of consumers and people who wish to use this data. There are approaches based on classical mathematical models, however, most of these results are too linear; that is, they use conventional evaluators to de ﬁ ne both quality aspects and results. In response, a new approach based on fuzzy logic is constructed as an application, which aims to complement and compare traditional models without the need to restrict thequality aspects with which it can be measured. As a methodology, it is done by obtaining data from each dataset through the SPARQL Endpoints provided by high category data- sets, classifying them within accessibility and trust dimensions, represented in 4 values: response time, scalability, trustworthiness and timeliness. This analysis is done internally for the values within the accessibility dimension, and exter- nally for the values within the conﬁdence dimension. In this way, it is possible to know or determine a better general qualityapproximationofthe Linked Open Data according to a large number ofquality evaluation variables, or even parameterize its own aspects in the model as a complement tothe already established models, through the concept of fuzzy logic.
This study confirms that economic growth produces and recreates new inequalities between men and women, rich and poor, as well as between different regions inside a country or a state. Beyond formal democracy, the expansion ofthe portfolio of human rights keeps alive the hope of reducing these inequalities. A pre-condition for this to happen is to divulge very broadly the contents ofthe human right towater among the populations most affected by problems of service, availability, quality and inefficiency in management described in this work. There is no indicator of economic performance that could compensate for thewater vulnerability that women experience in Hidalgo and, particularly, in CV, when facing the lack of safe, affordable and qualitywater. It is very likely that this situation is repeated in other parts ofthe country. According tothe constitution, it is the responsibility ofthe State to guarantee the human right towaterof Mexican citizens. It is still pending to perform more research work, as well as correlation and dissemination, for the rights attained on paper to be translated into actual benefits for rural women in Hidalgo and the rest of México.