Juan Antonio Vidales-Contreras

Transport of Coliphage PRD1 in a Surface Flow Constructed Wetland

A tracer study was conducted in a 3-ha surface flow constructed wetland to analyze transport performance of PRD1, an enteric virus model. The convection-dispersion equation (CDE), including a first-order reaction model, adequately simulated transport performance of PRD1 in the wetland under an average hydraulic loading rate of 82 mm/d. Convective velocity (v) and longitudinal dispersion coefficient (D) were estimated by modeling a conservative tracer (bromide) pulse through the wetland. Both PRD1 and bromide were simultaneously added to the entering secondary treated wastewater effluent. The mass of bromide and PRD1 recovered was 76 and 16%, respectively. The PRD1 decay rate was calculated to be 0.3/day. The findings of this study suggest that the CDE model and analytical moment equations represent a suitable option to characterize virus transport performance in surface flow constructed wetlands.

Transport and removal of coliphage PRD1 in constructed wetlands

The Convection Dispersion Equation (CDE) was used to calculate PRD1 and Br− transport parameters in a subsurface flow constructed wetland. Transport parameters from Br− displacement were applied into the CDE to estimate a 0.96 day−1 first order decay coefficient (k). The PRD1 breakthrough curves were also simulated to obtain effective cross-sectional area (Ac), longitudinal dispersion coefficient (D), convective velocity (v), and k. There was practically no difference between Ac and D for both tracers. However, the estimated convective velocity was higher for PRD1 than for Br−. Further simulations were conducted by taking experimental concentrations from prior research on surface and subsurface flow constructed wetlands. Dispersion number (d) was estimated to be between 0.17 and 0.029 by using PRD1 and Br− transport parameters. These parameters were also used to calculate wetland dimensionless removal (K). An analytical solution for the zero moment of the observed breakthrough curves was applied to estimate PRD1 fraction recoveries in the wetland by using d and K. The results of the present study suggest that this analytical solution may be an alternative design tool for pathogen removal estimation in subsurface flow constructed wetlands.

Total Growth of Tomato Hybrids Under Greenhouse Conditions

Often in intensive production of tomato, the fertilization is applied by the farmers without consider the suitable doses in order to cover nutritional requirements according to crop physiological stages. Thus, appropriate crop management is a strategic demand to maintain or increase tomato production. In spite of many researchers conducted experiments in this subject and data is available about physiological stage requirements for plant nutrition, only few studies have been focused to nutritional parameters. The crop growth curves and nutrient uptake for tomato may determine uptake rate for a particular nutrient eluding possible deficiencies and superfluous fertilizer consumption. The daily rates of nutrient uptake are depending on crop and wheater (Scaife and Bar-Yosef, 1995; Honorato et al., 1993; Magnificent et al., 1979; Miller et al, 1979); however, crop requirements and opportune fertilizer applications, are little known in many of fresh consumption crops. In Mexico, vegetable production is located at desert areas in the north and middle of the country where water shortages have constraints with impact on of water demands the crops of tomato, pepper and cucumber. Thus, the surface for crop production in greenhouses has increased from 350 ha in 1997 (Steta, 1999) to about 5000 ha in 2006 (Fonseca, 2006), because the increasing demand for quality products and the risk of losses on field for crop production.

The Effect of Drought Stress on Nutraceutical Properties of Zea mays Bran

The effect of drought stress on total phenols, hydroxycinnamic acids, and antioxidant capacity in Cebú, DK2027, and DK2034 maize hybrids was evaluated. Compared to irrigation treatment, total phenols decreased in drought stress treatment by 35.34%, 5.59%, and 31.57% in Cebú, DK2027, and DK2034, respectively. In addition, the levels of t-ferulic, c-ferulic and p-coumaric acids decreased by 17.74%, 23.93%, and 29.83% in Cebú, by 8.92%, 8.62%, and 24.03% in DK2027, and by 13.66%, 11.03%, and 10.38% in DK2034, respectively. The predominant hydroxycinnamic acid from bran extracts was t-ferulic (67% to 72%), followed by c-ferulic (20% to 21%), and p-coumaric (7% to 11%) for both irrigation and drought stress treatments, while caffeic and sinapic acids were found in traces or were not detected. The antioxidant capacity decreased by 8%, 3%, and 9% in trolox equivalents and 7%, 17%, and 14% in percentage of radical scavenging activity for Cebú, DK2027, and DK2034 genotypes, respectively. The reduction of total phenols, hydroxycinnamic acids, and antioxidant capacity is due to the radical scavenging and photoprotective actions of hydroxycinnamic acids against highly reactive oxygen species generated under drought stress treatment.ZusammenfassungDie Wirkung von Trockenstress auf Gesamtphenole, Hydroxyzimtsäuren und die antioxidative Kapazität in Cebú‑, DK2027- und DK2034-Maishybriden wurde untersucht. Verglichen mit dem Bewässerungsregime sanken während der Trockenstressbehandlung die Gesamtphenole um 35,34 %, 5,59 % bzw. 31,57 % in Cebú, DK2027 und DK2034. Darüber hinaus sank der Gehalt an t-Ferulasäure, c-Ferulasäure und p-Cumarsäure um 17,74 %, 23,93 % bzw. 29,83 % in Cebú, um 8,92 %, 8,62 % und 24,03 % in DK2027 und um 13,66 %, 11,03 % bzw. 10,38 % in DK2034. Die vorherrschende Hydroxyzimtsäure aus Kleieextrakten war im Bewässerungs- und Trockenstressregime t-Ferulasäure (67 %–72 %), gefolgt von c-Ferulasäure (20 %–21 %) und p-Cumarsäure (7 %–11 %). Kaffee- und Sinapinsäure wurden nur in Spuren oder überhaupt nicht gefunden. Die antioxidative Kapazität verringerte sich um 8 %, 3 % und 9 % gemessen in Trolox-Äquivalenten und um 7 %, 17 % und 14 % gemessen als prozentualer Anteil der radikalfangenden Aktivität für Cebú‑, DK2027- und DK2034-Genotypen. Die Verringerung der Gesamtphenole, der Hydroxyzimtsäuren und der antioxidativen Kapazität ist zurückzuführen auf die radikalfangenden und photoprotektiven Wirkungen der Hydroxyzimtsäuren gegen reaktive Sauerstoffspezies, die unter Trockenstress entstehen.

BIOMASS PRODUCTION AND QUALITY ESTIMATION OF Chlorella vulgaris (CLV2) UNDER LARGE SCALE PRODUCTION CONDITIONS

Present study was conducted for large scale biomass production of Chlorella vulgaris CLV2. Further, level of lipid, crude protein, chlorophyll content were also analysed for this produced biomass. In this study, two carbon sources viz. Carbon dioxide (CO2) or Sodium bicarbonate (NaHCO3) and two light sources (sun light or light-emitting diodes LEDs) were used from mass culturing of C. vulgaris CLV2. The study was conducted in 15 L culture containers. Results of study revealed that in case of maximum dry biomass (DB) concentration, no significant difference was reported amongst the NaHCO3 with LED (0.72 ± 0.04 g L -1 ) and sunlight (0.74 ± 0.04 g L -1 ), while in case of crude protein and chlorophyll a+b concentrations a significant difference was reported among these two (49.8% and 22.61 µg mL -1 , respectively) under normal autotrophic growth. Maximum lipid concentration (3.6%) was reported from the treatment containing NaHCO3 and LED. Further it was reported that lipid productivity (17.21 mg L -1 day -1 ) increased with the increasing biomass yield (477.78 mg L -1 day -1 ). Results of study revealed that C. vulgaris CLV2 biomass can be increased by manipulating carbon and light source. The final products can be used as biofuels (biomass, lipids) or human and animal feed supplement (proteins and chlorophyll).

Modeling of Corn Grain Drying by Runge- Kutta Method

Corn grain drying modelling is used to estimate moisture loss along time, and with this information improve the drying process, maximizing energy resources. The numerical method of Runge-Kutta is an alternative for the solution of ordinary differential equations, since obtaining the coefficients of the method is possible to simulate a very real approximation of the actual behaviour of drying process. In this research, the constants of the fourth order Runge-Kutta numerical method were calculated, a determination coefficient with R^2=1 between analytical solution and a numerical method was found. The mean error between the two solutions was 3.13x10 -5 . Uziel Francisco Grajeda-Gonzalez, Hector Flores-Breceda, Juana Aranda-Ruiz, Juan Antonio Vidales-Contreras, Humberto Rodriguez-Fuentes and Alejandro Isabel Luna-Maldonado *

Technological Skills in the Academic Performance of Students

The objective of this research was to analyze the effect of technological competence (teacher, Internet, smart classroom), to obtain academic performance of students of higher level of the Colleges of Agriculture and Veterinary Medicine at the Autonomous University of Nuevo Leon. We applied qualitative and quantitative methods, and simultaneously, a statistical design allowed us to make more reliable calculations. We also used two instruments: surveys and assessment test the research question.

Editorial: Advances and Trends in Development of Plant Factories

The plant factory is a facility that aids the steady production of high-quality vegetables all year round by artificially controlling the cultivation environment (e.g., light, temperature, humidity, carbon dioxide concentration, and culture solution), allowing growers to plan production. By controlling the internal environment, plant factories can produce vegetables about two to four times faster than by typical outdoor cultivation. In addition, as multiple cultivation shelves (a multi-shelf system) are used, the mass production of vegetables in a small space is facilitated. This research topic presents some new trends on intelligent measuring systems; environment controlled and optimization; flavonoids; phenylpropanoids, transcriptomes, and bacteria. Among some of the new findings on intelligent measuring systems, Chen et al. developed an automated measurement system to measure and record the plant weight during plant growth in plant factory. They found that plant weights measured by the weight measurement device are highly correlated with the weights estimated by the stereo-vision imaging system. Moriyuki and Fukuda devised a novel high-throughput diagnosis system using the measurement of chlorophyll fluorescence forming an image of 7200 seedlings acquired by a CCD camera and an automatic transferring machine. They used machine learning in order to extract biological indices and predict plant growth. Previously, Hashimoto et al. (2001) applied an intelligent control system consisting of a decision system based on neuronal networks and genetic algorithms to optimize the growth of hydroponic tomato plants during the seedling stage. Hwang et al. (2014) also proposed a plant factory automatic control system to collect crop image information (illuminance, temperature, humidity, EC, pH, and CO2) and provided crop environment control and service suitable for crop growth step (crop shape, size, color, and length). Related to environment controlled and optimization, Zheng et al. explored the effects of different density treatments on potato spatial distribution and yield in spring and fall. They concluded that increased density significantly increased potato yield, but the degree of influence associated with different growing seasons differed slightly. In Japan, there were 165 plant factories with artificial lighting (Kozai et al., 2015). Wang et al. added an air exchanger for cooling in plant production systems with artificial light (PPAL). They found that using air exchanger to introduce outdoor cold air is as an effective way to reduce electric-energy consumption with little effects on plant growth in a PPAL. Besides, the cultivation methods in a plant factory with artificial lighting (PFLA) were studied by Zhang et …

Recovery of lipophilic Malassezia species from two infants with otitis media in Monterrey, Nuevo Len, Mexico

Malassezia species are yeasts that can be present on healthy human skin but also associated with external otitis and other skin diseases. The aim of this work was the identification of Malassezia -lipophilic- species recovered from infants with otitis media. Microbiological culture, polymerase chain reaction (PCR) and sequencing were performed for Malassezia detection in samples obtained from two cases of infants with otitis media. We identified two strains of lipid-dependent Malassezia species: M. furfur and M. restricta. This is the first report regarding the presence of Malassezia species in infants with otitis media in Monterrey, Mexico. Key words: Malassezia, Malassezia furfur, Malassezia restricta, otitis media, infants, LSU rDNA D1/D2, yeasts.