Associations between dietary intake and physical activity, as behavioral indicators, with body fat in adolescents from Mexico / Asociaciones entre la ingesta dietética y la actividad física, como indicadores conductuales, con la grasa corporal en adolescentes de México

Introduction: the prevention of cardiometabolic diseases is currently a priority due to its relationship with COVID-19 complications. Unhealthy lifestyles, like inadequate diet and physical inactivity, are the cornerstone for obesity and cardiometabolic risk. Objective: to examine the association between diet and physical activity with body fat in Mexican adolescents. Methods: the study was cross-sectional. Data included socio-demographic variables, health history and smoking habit obtained through questionnaires; blood pressure and anthropometry measurements; food and nutrient intake through 24-hour recalls; and physical activities through the International Physical Activity Questionnaire (IPAQ). Univariate analyses were used and multiple models were built by stepwise forward selection (p ≤ 0.05 and biological plausibility). Results: participants were n = 230 students, 18.5 ± 0.4 years and 54.8 % men. Three models associated with body fat were obtained. In the first model, saturated fatty acids (β = 0.30, p = 0.028) were significant positive associated, while vigorous physical activity was significant negative associated as a protective factor (β = -0.007, p = 0.023). In the second model, total fat (β = 0.17, p = 0.005) was significant positive associated, and vigorous physical activity was significant negative associated (β = -0.007, p = 0.023). The third model included fruits and vegetables (β = -5.49, p = 0.092) and vigorous physical activity (β = -0.006, p = 0.058) as protective factors. Conclusions: dietary intake of total fat and saturated fatty acids, and vigorous physical activity, were significantly associated with body fat, while fruits and vegetables trended toward significance, in Mexican adolescents. Community-based programs that promote intake of protective foods and reduction of risky foods, and encourage vigorous physical activity, are needed in adolescents. (AU)

Introducción: la prevención de enfermedades cardiometabólicas es actualmente una prioridad por su relación con las complicaciones de la COVID-19. Los estilos de vida poco saludables son la piedra angular de la obesidad y el riesgo cardiometabólico. Objetivo: examinar la asociación entre dieta y actividad física con la grasa corporal en adolescentes mexicanos. Métodos: el estudio fue transversal. Los datos incluyeron variables sociodemográficas; mediciones de presión arterial y antropometría; ingesta de alimentos y nutrimentos con recordatorios de 24 horas; y actividades físicas con el cuestionario internacional de actividad física (IPAQ). Se utilizo análisis univariado y los modelos múltiples se construyeron mediante selección paso a paso hacia adelante (p ≤ 0.05 y plausibilidad biológica). Resultados: participaron n = 230 estudiantes, 18,5 ± 0,4 años y 54,8 % hombres. Se obtuvieron tres modelos asociados a la grasa corporal. En el primero, los ácidos grasos saturados (β = 0,30, p = 0,028) se asociaron significativamente de forma positiva, y la actividad física vigorosa significativamente de forma negativa como factor protector (β = -0,007, p = 0,023). En el segundo, la grasa total (β = 0,17, p = 0,005) se asoció positivamente y la actividad física vigorosa, negativamente (β = -0,007, p = 0,023). El tercer modelo incluyó frutas y verduras (β = -5,49, p = 0,092) y actividad física vigorosa (β = -0,006, p = 0,058) como factores protectores. Conclusiones: la ingesta dietética de grasas totales y saturadas y la actividad física vigorosa se asociaron significativamente con la grasa corporal, mientras que las frutas y verduras tendieron a ser significativas. Se necesitan programas comunitarios que promuevan la ingesta de alimentos protectores y la reducción de alimentos de riesgo, y fomenten la actividad física vigorosa en adolescentes. (AU)

Digestive glycosidases from cannonball jellyfish (Stomolophus sp. 2): identification and temporal-spatial variability.

Jellyfish are economically important organisms in diverse countries, carnivorous organisms that consume various prey (crustaceans, mollusks, bivalves, etc.) and dissolved carbohydrates in marine waters. This study was focused on detecting and quantifying the activity of digestive glycosidases from the cannonball jellyfish (Stomolophus sp. 2) to understand carbohydrate digestion and its temporal-spatial variation. Twenty-three jellyfish gastric pouches were collected in 2015 and 2016 in the Gulf of California in three localities (Las Guásimas, Hermosillo, and Caborca). Nine samples were in intra-localities from Las Guásimas. Chitinase (Ch), ß-glucosidase (ß-glu), and ß-N-acetylhexosaminidase (ß-NAHA) were detected in the gastric pouches. However, cellulase, exoglucanase, α-amylase, polygalacturonase, xylanase, and κ-carrageenase were undetected. Detected enzymes showed halotolerant glycolytic activity (i = 0-4 M NaCl), optimal pH, and temperature at 5.0 and 30-50 °C, respectively. At least five ß-glucosidase and two ß-N-acetylhexosaminidase were detected using zymograms; however, the number of proteins with chitinase activity is not precise. The annual variation of cannonball jellyfish digestive glycosidases from Las Guásimas between 2015-2016 does not show significant differences despite the difference in phytoplankton measured as chlorophyll α (1.9 and 3.4 mg/m3, respectively). In the inter-localities, the glycosidase activity was statistically different in all localities, except for ß-N-acetylhexosaminidase activity between Caborca and Hermosillo (3,009.08 ± 87.95 and 3,101.81 ± 281.11 mU/g of the gastric pouch, respectively), with chlorophyll α concentrations of 2.6, 3.4 mg/m3, respectively. For intra-localities, the glycosidase activity did not show significant differences, with a mean chlorophyll α of 1.3 ± 0.1 mg/m3. These results suggest that digestive glycosidases from Stomolophus sp. 2 can hydrolyze several carbohydrates that may belong to their prey or carbohydrates dissolved in marine waters, with salinity over ≥ 0.6 M NaCl and diverse temperature (4-80 °C) conditions. Also, chlorophyll α is related to glycosidase activity in both seasons and inter-localities, except for chitinase activity in an intra-locality (Las Guásimas).

Associations between dietary intake and physical activity, as behavioral indicators, with body fat in adolescents from Mexico.

Introduction: Introduction: the prevention of cardiometabolic diseases is currently a priority due to its relationship with COVID-19 complications. Unhealthy lifestyles, like inadequate diet and physical inactivity, are the cornerstone for obesity and cardiometabolic risk. Objective: to examine the association between diet and physical activity with body fat in Mexican adolescents. Methods: the study was cross-sectional. Data included socio-demographic variables, health history and smoking habit obtained through questionnaires; blood pressure and anthropometry measurements; food and nutrient intake through 24-hour recalls; and physical activities through the International Physical Activity Questionnaire (IPAQ). Univariate analyses were used and multiple models were built by stepwise forward selection (p ≤ 0.05 and biological plausibility). Results: participants were n = 230 students, 18.5 ± 0.4 years and 54.8 % men. Three models associated with body fat were obtained. In the first model, saturated fatty acids (ß = 0.30, p = 0.028) were significant positive associated, while vigorous physical activity was significant negative associated as a protective factor (ß = -0.007, p = 0.023). In the second model, total fat (ß = 0.17, p = 0.005) was significant positive associated, and vigorous physical activity was significant negative associated (ß = -0.007, p = 0.023). The third model included fruits and vegetables (ß = -5.49, p = 0.092) and vigorous physical activity (ß = -0.006, p = 0.058) as protective factors. Conclusions: dietary intake of total fat and saturated fatty acids, and vigorous physical activity, were significantly associated with body fat, while fruits and vegetables trended toward significance, in Mexican adolescents. Community-based programs that promote intake of protective foods and reduction of risky foods, and encourage vigorous physical activity, are needed in adolescents.

Introducción: Introducción: la prevención de enfermedades cardiometabólicas es actualmente una prioridad por su relación con las complicaciones de la COVID-19. Los estilos de vida poco saludables son la piedra angular de la obesidad y el riesgo cardiometabólico. Objetivo: examinar la asociación entre dieta y actividad física con la grasa corporal en adolescentes mexicanos. Métodos: el estudio fue transversal. Los datos incluyeron variables sociodemográficas; mediciones de presión arterial y antropometría; ingesta de alimentos y nutrimentos con recordatorios de 24 horas; y actividades físicas con el cuestionario internacional de actividad física (IPAQ). Se utilizo análisis univariado y los modelos múltiples se construyeron mediante selección paso a paso hacia adelante (p ≤ 0.05 y plausibilidad biológica). Resultados: participaron n = 230 estudiantes, 18,5 ± 0,4 años y 54,8 % hombres. Se obtuvieron tres modelos asociados a la grasa corporal. En el primero, los ácidos grasos saturados (ß = 0,30, p = 0,028) se asociaron significativamente de forma positiva, y la actividad física vigorosa significativamente de forma negativa como factor protector (ß = -0,007, p = 0,023). En el segundo, la grasa total (ß = 0,17, p = 0,005) se asoció positivamente y la actividad física vigorosa, negativamente (ß = -0,007, p = 0,023). El tercer modelo incluyó frutas y verduras (ß = -5,49, p = 0,092) y actividad física vigorosa (ß = -0,006, p = 0,058) como factores protectores. Conclusiones: la ingesta dietética de grasas totales y saturadas y la actividad física vigorosa se asociaron significativamente con la grasa corporal, mientras que las frutas y verduras tendieron a ser significativas. Se necesitan programas comunitarios que promuevan la ingesta de alimentos protectores y la reducción de alimentos de riesgo, y fomenten la actividad física vigorosa en adolescentes.

Low prevalence of ideal levels in cardiovascular behavior metrics among Mexican adolescents.

BACKGROUND: Lifestyle changes when transitioning from high-school to college expose students to unhealthy behaviors associated with high cardiovascular risk. The study aimed to assess the cardiovascular behavior metrics according to the AHA criteria, in freshman college adolescents from Northwest Mexico. METHODS: The study was cross-sectional. Demographics and health history were collected by questionnaires. Four behaviors were evaluated: diet quality using a duplicated FFQ, physical activity (PA) using the IPAQ, smoking, and body mass index (BMI) percentile; blood pressure was measured as a biological metric. Intakes were averaged and summed for each food group; sodium and saturated fat were calculated using the Mexican System of Food Equivalents or the USDA Database. Metrics were categorized into ideal, intermediate or poor level according to the AHA criteria. Diet outliers (± 3 SD) were trimmed and data was tested for normality. Mean±SD were calculated for continuous and percentages for categorical variables. Chi-square test compared the prevalence of demographic variables and levels of each cardiovascular metric by sex. Independent T-test evaluated differences in anthropometrics, dietary, and PA by sex, and the prevalence of ideal vs. non-ideal dietary intakes. RESULTS: Participants were n = 228, 55.6% men, age = 18.5±0.4 y. A higher prevalence of men indicated working, playing sports, and family history hypertriglyceridemia (p < 0.05). Men showed higher weight, height, BMI, waist, blood pressure, and lower PA and body fat (p < 0.05). Concerning diet quality, significant differences by sex were observed in nuts and seeds (1.1±0.6 and 0.9±0.6 oz/week, p = 0.042) and processed meats (749.8±639 and 503.6±300.3 g/week, p = 0.002); only fish and shellfish group reached AHA recommendations (513.1 ± 450.7 vs. 501.7 ± 428 g/week, p = 0.671) for men and women, respectively. Ideal level was reached by 70.9% participants for BMI percentile, 87% for smoking, 67.2% for blood pressure, 25.9% for PA, and 12.2% for diet score. Regarding food groups and nutrients, the lower prevalence in the ideal level was for sugar-sweetened beverages (10%, p = 0.013) and processed meats (4.8%, p = 0.208), and the highest for fish and shellfish (87.8%, p = 0.281) . CONCLUSIONS: The diet and PA patterns of Northwest Mexican freshman adolescents make them a high-risk group for developing long-term unhealthy habits and cardiovascular complications early in adulthood.

Treatment of tequila distillation volatile residues by electrochemical oxidation using titanium electrodes.

Tequila production occurs in Mexico's designated area of origin, principally in the Jalisco State. Its residues are a challenge in treatment and tracking due to a lack of technology, non-economic treatments available, low environmental consciousness and incipient control from authorities. In 2021, average production was close to 1.5 million tequila litres per day with an estimated residue yield of 10-12 litres of stillage (tequila vinasses) per tequila litre produced, including volatile fractions. This research aims to reduce organic matter by electrooxidation (EO) from 5 distillation volatile residual effluents (two-stage still distillation) from three tequila distilleries, first and second-stage heads and heads and tails and second-stage non-evaporated fraction. Round 3 mm titanium (grade-1) electrodes (one anode and one cathode) were used, with fixed voltage to a value of 30 VDC at 0, 3, 6, 9 and 12 h with 75 experiments. Gas chromatography was used to analyse methanol, ethanol, acetaldehyde, ethyl acetate, n-propanol, sec-butanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate content. Treatment shows positive results, reducing organic matter content in all effluents in a Chemical Oxygen Demand COD range of 580-1880 mg/L.h, particularly useful in the second-stage non-evaporated fraction for water recovery.HIGHLIGHTSResidual effluent treatment is beneficial to environmental and resource sustainability.Process without adding materials achieving cleaner treated effluents.Process aimed as the final step to recover water.This process could help the Tequila industry to reach a higher sustainability level by reducing water usage and untreated residues.

Reproducibility and validity of a food frequency questionnaire to assess cardiovascular health-related food intake among Mexican adolescents.

There is a lack of region-adapted tools to evaluate diet as a risk factor for cardiovascular disease (CVD) in adolescents. The study aim was to evaluate the reproducibility and validity of a paper-based and region-adapted food frequency questionnaire (FFQ) designed to assess CVD-related food and nutrient intakes of adolescents from Northwest México. The study design was cross-sectional. The FFQ was developed in a two-step process: prototype designing and a pilot test, with re-tested in a 3-month period, along with two administrations of 24 h-recall (24 hR). Pearson's and intra-class correlation coefficients (PCC and ICC) were assessed. Bland-Altman plots, limits of agreement and quintile classifications were carried out. Participants (n 221) were 53·8 % male, 18·5 ± 0·4 years old. Reproducibility had a median PCC = 0·66 for processed meats, ranging from 0·40 (saturated fat) to 0·74 (fish & shellfish), P = 0·001. ICC ranged from 0·53 (saturated fat) to 0·80 (sodium; and nuts, seeds and legumes), P = 0·001. Validity comparing FFQ1 v. 24 hR mean, PCCs ranged from 0·12 (P = 0·06) to 0·95 (P = 0·001), and ICC from 0·20 (P = 0·048) to 0·88 (P = 0·001); comparing FFQ2 v. 24 hR mean, PCCs ranged from 0·07 (P = 0·25) to 0·46 (P = 0·001), and ICC from 0·15 (P = 0·106) to 0·58 (P = 0·001). The FFQ overestimated the intake of all food groups and nutrients (P < 0·05), while Cohen's κ showed coefficients lower than 0·20. The proposed FFQ represents a moderately validated tool to estimate CVD-related food and nutrient intakes as a risk factor, which can be used in combination with multiple administrations of 24 hRs, as a critical mean in future interventions intended to reduce cardiometabolic risk in adolescents.

Efficiency of an up-flow Anaerobic Sludge Blanket reactor coupled with an electrochemical system to remove chloramphenicol in swine wastewater.

The application and design of treatment systems in wastewater are necessary due to antibiotics' potential toxicity and resistant genes on residual effluent. This work evaluated a coupled bio-electrochemical system to reduce chloramphenicol (CAP) and chemical oxygen demand (COD) on swine wastewater (SWW). SWW characterization found CAP of <10 µg/L and 17,434 mg/L of COD. The coupled system consisted of preliminary use of an Up-flow Anaerobic Sludge Blanket Reactor (UASB) followed by electrooxidation (EO). The UASB reactor (primary stage) was operated for three months at an organic load of 8.76 kg of COD/m3d and 50 mg CAP/L as initial concentration. In EO, we carried out a 22 (time operation and intensity) factorial design with a central composite design; we tried two Ti cathodes and one anode of Ti/PbO2. Optimal conditions obtained in the EO process were 240 min of operation time and 1.51 A of current intensity. It was possible to eliminate 44% of COD and 64.2% of CAP in the preliminary stage. On bio-electrochemicals, total COD and CAP removal were 82.35 and >99.99%, respectively. This coupled system can be applied to eliminate antibiotics and other organic pollutants in agricultural, industrial, municipal, and other wastewaters.

Statistical optimization of arsenic removal from synthetic water by electrocoagulation system and its application with real arsenic-polluted groundwater.

Arsenic presence in the water has become one of the most concerning environmental problems. Electrocoagulation is a technology that offers several advantages over conventional treatments such as chemical coagulation. In the present work, an electrocoagulation system was optimized for arsenic removal at initial concentrations of 100 µg/L using response surface methodology. The effects of studied parameters were determined by a 23 factorial design, whereas treatment time had a positive effect and current intensity had a negative effect on arsenic removal efficiency. With a p-value of 0.1629 and a confidence of level 99%, the type of electrode material did not have a significant effect on arsenic removal. Efficiency over 90% was reached at optimal operating conditions of 0.2 A of current intensity, and 7 min of treatment time using iron as the electrode material. However, the time necessary to accomplish with OMS arsenic guideline of 10 µg/L increased from 7 to 30 min when real arsenic-contaminated groundwater with an initial concentration of 80.2 ± 3.24 µg/L was used. The design of a pilot-scale electrocoagulation reactor was determined with the capacity to meet the water requirement of a 6417 population community in Sonora, Mexico. To provide the 1.0 L/s required, an electrocoagulation reactor with a working volume of 1.79 m3, a total electrode effective surface of 701 m2, operating at a current intensity of 180 A and an operating cost of 0.0208 US$/day was proposed. Based on these results, electrocoagulation can be considered an efficient technology to treat arsenic-contaminated water and meet the drinking water quality standards.

Cannonball jellyfish digestion: an insight into the lipolytic enzymes of the digestive system.

The digestive system and metabolism of the cannonball jellyfish Stomolophus sp. 2 are not well-known. The digestion study was critical to explain its ecology and bloom success. Different enzymes are involved in food digestion, which hydrolyze carbohydrates, proteins, and lipids. This study detected lipolytic activity in enzymatic extracts from gastric pouches of Stomolophus sp. 2 collected in the summer of 2013 at Bahía de Kino, Sonora, México (28°47'47″N 111°57'25″W). Lipase/esterase activity showed optimal pH at 11.0 and 50-60 °C with a half-life (t1/2) of 33 min at 55 °C, whereas halotolerance of this activity was recorded from 0-4 M NaCl. Metal ions Ca2+ and Mn2+ did not affect the activity, but Mg2+ decreased it 14.2% ± 3.15, while chelating agents as ethylenediaminetetraacetic acid reduced the activity 8.55% ± 2.13. Inhibition of lipase/esterase activity with tetrahydrolipstatin and paraoxon-ethyl decreased the activity 18.2% ± 2.3, and 62.80% ± 0.74, respectively, whereas phenylmethanesulfonyl fluoride (a protease inhibitor) did not affect it. The enzyme displayed a higher specificity for short-chain triglycerides, but triolein, coconut oil, olive oil, and fish oil were hydrolyzed. For the first time, phospholipase activity from the gastric pouch of Stomolophus sp. 2 was detected using L-α-phosphatidylethanolamine from chicken egg yolk as a substrate. These results suggest that Stomolophus sp. 2 hydrolyze several kinds of lipids, and lipolytic enzymes are active at alkaline pH under different saline conditions, which may be essential to digest different preys.

Characterization of cannonball jellyfish (Stomolophus sp. 2) blue protein: a pH-stable pigment.

Pigments are present in a broad variety of terrestrial and aquatic organisms. The cannonball jellyfish (Stomolophus sp. 2) is an important fishery resource in the northwest of Mexico and is processed to be traded and consumed as seafood. During the process, water with a soluble blue pigment and other compounds are discarded to the environment. In this work, we present some properties of the blue pigment from Stomolophus sp.2 (S2bp), to decide if it could be considered as a potential value-added waste and avoid the blue proteinaceous pigment wastewater. S2bp was purified to homogeneity and had a molecular mass of 28.0 kDa; this protein exhibited a ʎmax at 650 nm, contained Zn2+ and Cu2+ metal ions, and was stable from 10 to 50 °C and in a pH range of 3.0 to 13.0 for 1 h. It had halotolerant characteristics maintaining the blue coloration in a broad range of ionic strength (0-4 M NaCl) and showed changes in ʎmax with chaotropic salts. In addition, S2bp was stable in the presence of organic acids and EDTA and in zwitterionic, anionic, and nonionic detergents at critical micellar concentration. However, oxidant reagents like NaClO and H2O2 decrease the coloration. These results show that the jellyfish pigment is a stable protein which makes it an alternative pigment for the food industry.

Simultaneous extraction of antibiotic and estrogen from animal blood serum using aqueous two-phase systems as predictor of environmental impact.

Efficient analytical methods are required for optimizing dosage of veterinary antibiotics and hormones in order to reduce toxicity and antimicrobial resistance in the environment. Thus, the objective of this work was to develop a rapid and low-cost method for determination of hormone estradiol and antibiotic chlortetracycline in bovine and porcine blood serum by aqueous two-phase system (ATPS) extraction and capillary electrophoresis quantification. ATPS based on ionic liquid cholinium alaninate and citrate salt along with mixtures of protic and aprotic polar solvents were evaluated in terms of recovery of extraction (%R). The liquid-liquid equilibrium, phase diagrams, and tie lines are discussed. Antibiotic migrated to solvent-rich phase (R ≈ 89.0%) to all systems. Estradiol migrates to ionic liquid-rich phase; however, addition of 10% methanol changed partition to solvent-rich phase (R ≈ 89.7%). The method has high recovery and cleanliness, is cost-efficient, scalable, and hence is adequate for screening of antibiotics and hormones tested in animal blood serum for dosage optimization and to predict their environment.

Biochemical and Molecular Characterization of a Native Haloalkalophilic Tolerant Strain from the Texcoco Lake.

In the last decade several new genera have been isolated in alkaline and halophile growth conditions. The studies conducted in the Texcoco Lake soils have shown a generalized microbial adaptation to the specific conditions. In this research work, morphological and phylogenetic characterization of the HN31(22) strain that was isolated from the cited soil is presented. The strain was identified as a Gram-positive halophile and alkaline tolerant bacteria from the Nesterenkonia genus, which uses different substrates in metabolic processes.

Simultaneous quantification of antibiotics in wastewater from pig farms by capillary electrophoresis.

Pig farming is an important activity in the economic development of Mexico with millions of tons of meat produced annually. Antibiotics are used in therapeutic dose to prevent diseases, and sometimes as growth promoters. These compounds are not completely metabolized; they are carried into the environment in its active form at concentrations that could induce antibiotic resistance in bacteria, which could be transferred to human pathogens by horizontal gene transfer. The objective of this work was to develop methods of analysis for simultaneous quantification of the antibiotics Oxytetracycline (OXT), Chlortetracycline (CLT), Enrofloxacin (ENRO) and Ciprofloxacin (CIPRO) by field-amplified sampling injection in capillary zone electrophoresis (FASI-CZE). The method was validated by parameters of (1) linearity, obtaining a lineal range of 0.05 at 1 µg mL-1 for ENRO and CIPRO, and from 0.1 to 1 µg mL-1 for OXT and CLT; (2) precision, obtaining values <5% of standard deviation for CIPRO and ENRO and <10% of standard deviation for OXT and CLT; (3) accuracy, with recovery values from 93 to 115%; (4) selectivity, with values of resolution >2 for the all antibiotics tested. To prove the method, a sample of wastewater from a local pig farm was analyzed, detecting a concentration of 0.140 ±â€¯0.009 for OXT. This concentration was higher than the minimal selective concentration, indicating the point in which resistance to a determined antibiotic could develop. The methods were validated with precision and sensitivity comparable to chromatographic methods, which can be used to analyze wastewater from pig farms directly.

Influence of redox mediators and salinity level on the (bio)transformation of Direct Blue 71: kinetics aspects.

The rate-limiting step of azo dye decolorization was elucidated by exploring the microbial reduction of a model quinone and the chemical decolorization by previously reduced quinone at different salinity conditions (2-8%). Microbial experiments were performed in batch with a marine consortium. The decolorization of Direct Blue 71 (DB71) by the marine consortium at 2% salinity, mediated with anthraquinone-2,6-disulfonate (AQDS), showed the highest rate of decolorization as compared with those obtained with riboflavin, and two samples of humic acids. Moreover, the incubations at different salinity conditions (0-8%) performed with AQDS showed that the highest rate of decolorization of DB71 by the marine consortium occurred at 2% and 4% salinity. In addition, the highest microbial reduction rate of AQDS occurred in incubations at 0%, 2%, and 4% of salinity. The chemical reduction of DB71 by reduced AQDS occurred in two stages and proceeded faster at 4% and 6% salinity. The results indicate that the rate-limiting step during azo decolorization was the microbial reduction of AQDS.

Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4.

Characterization of extracellular amylase produced by haloalkalophilic strain Kocuria sp. HJ014.

The haloalkaliphilic bacterium Kocuria sp. (HJ014) has the ability to produce extracellular amylase. The aim of this study was to purify and characterize this protein. The amylase enzyme with a specific activity of 753,502 U/mg was purified 5.7- fold using Sepharose 4B and Sephacryl S-300 gel filtration columns. The molecular weight of the enzyme was 45,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The amylase showed maximum activity at pH 9 and 50°C in the presence of 3.5 M NaCl. The Km was 3.0 mg/ml and Vmax 90.09 U/ml. It was found that extracellular amylase from Kocuria sp. has a high industrial potential.

Hepatocyte nuclear factor-4α, a multifunctional nuclear receptor associated with cardiovascular disease and cholesterol catabolism.

Cardiovascular diseases (CVDs), the leading cause of death worldwide, are associated with high plasma cholesterol levels. The conversion of cholesterol to bile acids (BAs) accounts for about 50% of total cholesterol elimination from the body. This phenomenon occurs in the liver and is regulated by nuclear receptors such as hepatocyte nuclear factor-4α (HNF-4α). Therefore, special emphasis is given to HNF-4α properties and its multifunctional role, particularly in the conversion of cholesterol to BAs. HNF-4α is a highly conserved transcription factor that has the potential capacity to transactivate a vast number of genes, including CYP7 which codes for cholesterol 7α-hydroxylase (CYP7A1; EC 1.14.13.17), the rate-limiting enzyme of BA biosynthesis. The fact that HNF-4α transactivation potential can be modulated via phosporylation is of particular interest. Additional findings on structural and functional characteristics of HNF-4α may eventually present alternatives to control the levels of cholesterol in the body and consequently reduce the risk of CVDs.

Quantitative microbial risk assessment of Cryptosporidium and Giardia in well water from a native community of Mexico.

Cryptosporidium and Giardia are gastrointestinal disease-causing organisms transmitted by the fecal-oral route, zoonotic and prevalent in all socioeconomic segments with greater emphasis in rural communities. The goal of this study was to assess the risk of cryptosporidiosis and giardiasis of Potam dwellers consuming drinking water from communal well water. To achieve the goal, quantitative microbial risk assessment (QMRA) was carried out as follows: (a) identification of Cryptosporidium oocysts and Giardia cysts in well water samples by information collection rule method, (b) assessment of exposure to healthy Potam residents, (c) dose-response modelling, and (d) risk characterization using an exponential model. All well water samples tested were positive for Cryptosporidium and Giardia. The QMRA results indicate a mean of annual risks of 99:100 (0.99) for cryptosporidiosis and 1:1 (1.0) for giardiasis. The outcome of the present study may drive decision-makers to establish an educational and treatment program to reduce the incidence of parasite-borne intestinal infection in the Potam community, and to conduct risk analysis programs in other similar rural communities in Mexico.

Occurrence and quantitative microbial risk assessment of Cryptosporidium and Giardia in soil and air samples.

BACKGROUND: Cryptosporidium oocysts and Giardia cysts can be transmitted by the fecal-oral route and may cause gastrointestinal parasitic zoonoses. These zoonoses are common in rural zones due to the parasites being harbored in fecally contaminated soil. This study assessed the risk of illness (giardiasis and cryptosporidiosis) from inhaling and/or ingesting soil and/or airborne dust in Potam, Mexico. METHODS: To assess the risk of infection, Quantitative Microbial Risk Assessment (QMRA) was employed, with the following steps: (1) hazard identification, (2) hazard exposure, (3) dose-response, and (4) risk characterization. RESULTS: Cryptosporidium oocysts and Giardia cysts were observed in 52% and 57%, respectively, of total soil samples (n=21), and in 60% and 80%, respectively, of air samples (n=12). The calculated annual risks were higher than 9.9 × 10(-1) for both parasites in both types of sample. CONCLUSIONS: Soil and air inhalation and/or ingestion are important vehicles for these parasites. To our knowledge, the results obtained in the present study represent the first QMRAs for cryptosporidiosis and giardiasis due to soil and air inhalation/ingestion in Mexico. In addition, this is the first evidence of the microbial air quality around these parasites in rural zones.

Isolation and phylogenic identification of soil haloalkaliphilic strains in the former Texcoco Lake.

A wide diversity of organisms exists in soil. Well-adapted groups can be found in extreme environments. A great economic and metabolic potential for extremozymes produced by organisms living at extreme environments has been reported. Extreme characteristics such as high salt content and high pH level make the soil of the former Texcoco Lake a unique place which has not been exploited. Therefore, in this study, 66 strains from soil of the former Texcoco Lake were isolated and phylogenetically analyzed using universal oligonucleotide primers. Different genera such as Kocuria, Micrococcus, Nesterenkonia, Halomonas, Salinicoccus, Kurthia, Gracilibacillus, and Bacillus were found. However, only 22 from all isolated strains were identified at specie level.