Assessment of risk to infants and children resulting from the ingestion of contaminants in water is an important component of the analysis of possible environmental hazards. Children and infants represent a sensitive life stage because exposure to contaminants in early life can have developmental and long-lasting adverse effects. Children and infants tend to ingest relatively large amounts of water on a bodyweight-adjusted basis, especially those that are fed in early life with formula that is re-constituted or diluted with water. This article presents statistical estimates of the amounts of community water ingested by formula-fed infants based on nationwide sample survey data that support identification of respondents who consume formula and the amounts of water they ingest. Included are specific estimates of the amounts of community water ingested in formula. Estimates of total community water ingestion by children and infants who consume formula can be especially useful in exposure assessment since they represent a highly exposed population. For example, mean community water ingestion by infants 1 to 3 months of age who consume formula is 627 mL/day (136 mL/kg/day) and the 95th percentile is 1096 mL/day (290 mL/kg/day).

The ability of 17α-ethinylestradiol (EE2) to elevate vitellogenin levels were investigated in male flounder Platichthys flesus and vitellogenin concentrations in flounders from the Danish coastal environment were determined. Male flounders were exposed to 17α-ethinylestradiol (EE2) via food or water. Average vitellogenin concentrations in the control fish ranged between 25 and 100 ng mL−1. Exposure to 5.1, 8.1 and 16.8 ng EE2 L−1 in water and 500 and 5000 ng EE2 kg−1 body weight (bw) every second day in the food increased the plasma vitellogenin concentration in a concentration and time dependent manner, whereas exposure to 2.7 ng EE2 L−1 in water for 21 d and 5 and 50 ng EE2 kg−1 bw for 12 days in the food did not. EE2 could be detected in liver and testes (but not in muscle) after exposure to 8.1 and 16.8 ng EE2 L−1 in the water and 5000 ng EE2 kg−1 bw in the food; the highest concentration was 6 ng g−1 wet weight in liver. The majority of the male flounders collected from nine coastal Danish sites from 1999 to 2004 had vitellogenin concentrations below 100 ng mL−1, and only at two sites moderate estrogenic inputs were indicated.

Se evaluó el efecto de la adición de electrolitos en el agua y alimento sobre las variables productivas y sanguíneas durante la etapa de fi nalización, bajo condiciones de estrés térmico crónico (28 a 35 d de edad) y estrés térmico agudo simulado (ETAS) a los 36 d de edad, en pollos de engorde. Se utilizaron 192 pollos distribuidos al azar, con ocho repeticiones/tratamiento (ocho pollos/ repetición). Las tres tratamientos (T), a saber: T1: sin adición electrólitos; T2: adición de electrólitos en alimento; T3: adición electrólitos en agua. La fuente de electrólitos fue: NaHCO3 (0,83%); NH4Cl (0,07%); NaCl (0,30%), obteniéndose un balance electrolítico de 240 mEq. Se evaluaron: variables productivas y sanguíneas; pH, presiones parciales de O2, de CO2 y HCO3, hematocrito, hemoglobina, proteína plasmática, glóbulos blancos, glóbulos rojos y electrólitos sanguíneos, y mortalidad. Los datos fueron analizados por ANAVAR. Los resultados muestran que la adición de electrólitos en agua o alimento durante el estrés crónico, aumentó el consumo de agua en pollos suplementados, sin existir efectos significativos en parámetros productivos. La mortalidad durante el ETAS disminuyó (22%) (P<0,001) en el T3, los niveles de Na+ (129,73 ± 1,87 mEq/l) y Cl- (111,73 ± 1,54 mEq/l) variaron (P< 0,05) siendo los del T1 mayores a los del T3. Se determina que la adición de electrólitos mantiene las variables productivas y sanguíneas, logrando disminuir la mortalidad en el ETAS. | The effect of the addition of electrolytes in water and feed on productive and blood variables during the fi nal stage, under conditions of chronic heat stress (28 to 35 d of age) and acute heat stress simulated (AHSS) at 36 d of age in broilers were studied. 192 broilers were randomly distributed, with eight replicates/treatment (eight broilers/ repeat). The three treatments (T) as follows: T1: without electrolytes addition; T2: addition of electrolytes in feed; T3: adding electrolytes in water. The source of electrolytes was: NaHCO3 (0.83%), NH4Cl (0.07%), NaCl (0.30%), obtaining an electrolyte balance of 240 mEq. Variables evaluated were: production and blood pH, partial pressures of O2, CO2 and HCO3, hematocrit, hemoglobin, plasma protein, white blood cells, red blood cells, blood electrolytes, and mortality. Data were analyzed by ANOVA. The results showed that the addition of electrolytes in water or feed during chronic stress, increased water consumption in Broilers supplemented, with no signifi cant effects on production parameters. Mortality during the AHSS decreased (22%) (P<0.001) in the T3, levels of Na + (129.73 ± 1.87 mEq/l) and Cl-(111.73 ± 1.54 mEq/l) varied (P<0.05) being greater than T1 T3. Determined that the addition of electrolyte helps maintan blood production variables stable, decreasing mortality in the AHSS.

Existen microorganismos patógenos que tienen la capacidad de adherirse a superficies tanto de acero inoxidable, teflón, vidrio e incluso de alimentos en forma de biopelículas. Las biopelículas representan importantes problemas en la industria alimentaria, ya que pueden generar perjuicios en la salud, en las operaciones y procesos. La tendencia actual en el consumo de alimentos frescos aumenta la preocupación por tener una desinfección adecuada que garantice la calidad e inocuidad para el consumo humano. Varios estudios han demostrado que el agua electrolizada es efectiva para reducir e inactivar microorganismos deterioradores y patógenos en diversas superficies. El objetivo de este trabajo fue estudiar el efecto antimicrobiano del AEN en células libres y biopelículas de Listeria monocytogenes Scott A y EGDe en superficies de acero inoxidable, jitomate y aguacate. Se inocularon placas de acero inoxidable y los vegetales con L. monocytogenes para después ser expuestos al AEN a diferentes tiempos y concentraciones, así como la eliminación de la flora nativa. La concentración efectiva para llegar a niveles no detectables para L. monocytogenes Scott A en células libres fue 150 ppm y para biopelículas en acero inoxidable de 400 ppm, en el caso de L. monocytogenes EGDe para células libres fue 30 ppm y para biopelículas en placas de acero inoxidable de 70 ppm, para el jitomate se obtuvo eliminación de flora asociada a partir de 70 ppm, y para aguacate a 200 ppm. Para aguacate y jitomate inoculados con L. monocytogenes EGDe fue de 300 y 70 ppm respectivamente y para L. monocytogenes Scott A fue de 500 y 200 ppm respectivamente. Se considera que el AEN es una alternativa viable para utilizarse como agente sanitizante en la limpieza y desinfección de superficies y alimentos.

Synergic action has been studied of the pesticides (imazalil, iprodione, tebuconazole and ethofumesate) found in the water bodies of the Azov Sea basin on phyto- and zooplankton, zoobenthos, sturgeons, gobies and Cyprinidae. These pesticides in the combination applied are shown to have a negative effect on some links of the trophic chain even if they are used in concentrations smaller than maximum admissible concentrations adopted for fishery waterbodies

The mongraph presents the development and validation of kinetic methods for analysis of quantitative determination of the content of pesticides on the basis of their inhibitory influence in the chosen indicatory reactions. Spectrophotometry procedure allowed observing the speed of chemical reactions at wave length of maximum absorption of the obtained transitory complex metal ion-pesticide-substrate. Detecting the effect of pesticides on the speed of chosen indicatory reactions, allowed presuming the possible mechanism of their effect by building triple complex due to bonding of the metal ion to free electrons of donor atoms in the pesticide molecule. The mongraph explains the inhibitory effect of pesticides expressed by decrease of catalytic activity of the catalyst, due to the fact that depending on both the stability of the formed triple complex and strength of the bond between the donor pesticide atom and metal ion, much more energy is needed for such complex to decompose, which leads to decrease of the speed of indicatory reaction. During the elaboration of kinetic methods, we observed the effect of reaction parameters on the speed o indicatory reactions, the aim of which was to choose the optimal experimental conditions for determination of pesticides. In a part of the mathod elaboration, we tested the effect of pH values in reacction environment, the concentration of indicatory substances and the catalyst on the speed of chosen indicatory reactions. We constructed the calibration curves for determining the pesticides and tested the accuracy and precision of the proposed kinetic methods. We also tested the effect of interference on the speed of inhibitory reactions. The work also icluded defining limits for detection and limits for determination of the tested pesticides. The elaborated kinetic methods were applied for determining pesticides in food and water samples. The food and water samples required a complex preparation due to the presence of numerous substances that had an effect on determining the pesticides by applying these methods. The present distracting substances in the samples were removed by applying extraction methods, which at the same time increased the selectivity of kinetic methods. Validation of the proposed kinetic methods was performed by comparing the obtained results with the results obtained by the reerent HPLC method.

Se evaluó el efecto de la adición de electrolitos en el agua y alimento sobre las variables productivas y sanguíneas durante la etapa de fi nalización, bajo condiciones de estrés térmico crónico (28 a 35 d de edad) y estrés térmico agudo simulado (ETAS) a los 36 d de edad, en pollos de engorde. Se utilizaron 192 pollos distribuidos al azar, con ocho repeticiones/tratamiento (ocho pollos/ repetición). Las tres tratamientos (T), a saber: T1: sin adición electrólitos; T2: adición de electrólitos en alimento; T3: adición electrólitos en agua. La fuente de electrólitos fue: NaHCO3 (0,83%); NH4Cl (0,07%); NaCl (0,30%), obteniéndose un balance electrolítico de 240 mEq. Se evaluaron: variables productivas y sanguíneas; pH, presiones parciales de O2, de CO2 y HCO3, hematocrito, hemoglobina, proteína plasmática, glóbulos blancos, glóbulos rojos y electrólitos sanguíneos, y mortalidad. Los datos fueron analizados por ANAVAR. Los resultados muestran que la adición de electrólitos en agua o alimento durante el estrés crónico, aumentó el consumo de agua en pollos suplementados, sin existir efectos significativos en parámetros productivos. La mortalidad durante el ETAS disminuyó (22%) (P<0,001) en el T3, los niveles de Na+ (129,73 ± 1,87 mEq/l) y Cl- (111,73 ± 1,54 mEq/l) variaron (P< 0,05) siendo los del T1 mayores a los del T3. Se determina que la adición de electrólitos mantiene las variables productivas y sanguíneas, logrando disminuir la mortalidad en el ETAS.

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Riverine transport of dissolved inorganic carbon (DIC) from land to the ocean is an important carbon flux that influences the carbon budget at the watershed scale. However, the dynamics of DIC in an entire river network has remained unknown, especially in mountainous Japanese watersheds. We examined the effects of watershed land use and geology on the transports of inorganic carbon as well as weathered silica (Si) and calcium (Ca) in the Iwaki River system where agricultural and residential areas have developed in the middle and lower parts of the watershed. The concentration and stable carbon isotope ratios (δ¹³C) of DIC showed the longitudinal increase of ¹³C-depleted inorganic carbon along the river. As a result, most streams and rivers were supersaturated in dissolved CO₂ that will eventually be emitted to the atmosphere. The possible origin of ¹³C-depleted carbon is CO₂ derived from the decomposition of organic matter in agricultural and urban landscapes, as well as from in-stream respiration. In addition, agricultural and urban areas, respectively, exported the large amount of dissolved Si and Ca to the rivers, suggesting that CO₂ increased by respiration accelerates the chemical weathering of silicate and carbonate materials in soils, river sediments, and/or urban infrastructure. Furthermore, riverine bicarbonate flux is likely to enter shell carbonates of Corbicula japonica, an aragonitic bivalve, in the downstream brackish lake (Lake Jusan). These results revealed that the flux of DIC from the human-dominated watersheds is a key to understanding the carbon dynamics and food-web structure along the land-to-river-to-ocean continuum.

Se analiza en juveniles en etapa de engorde (7 g) de Cherax quadricarinatus, el ritmo circadiano de los niveles de proteínas totales, la actividad de las proteasas, lipasas y amilasas, y su posible modificación en función del momento de alimentación matutino (8 h) y vespertino (17 h). En general, la actividad de las enzimas digestivas de los juveniles de C. quadricarinatus no mostró un patrón circadiano de secreción, a excepción de las lipasas, donde se observó un incremento de actividad hacia la tarde-noche y disminución hacia las primeras horas de la mañana. Los niveles de proteína total, la actividad de proteinasas y amilasas registradas en la glándula digestiva, permanecieron prácticamente inalterados en todos los experimentos. A pesar de ello, se observó tendencia a que los niveles de actividad de proteinasas disminuyan luego del pulso de alimentación, recuperando los niveles anteriores 3 h después, independientemente del horario de alimentación. En cambio la actividad de amilasa no mostró ninguna tendencia por efecto del horario de alimentación. El estudio de los patrones de secreción de las enzimas digestivas y sus posibles modificaciones, podría ser utilizado como una herramienta para establecer los momentos del día más propicios para la alimentación de los juveniles en cultivo.