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The genus Physalis includes species used for food, medicinal and artisanal purposes. The wild tomato (Physalis angulata L.), which is common in the mixed maize cultivation called "the milpa", is cultivated in some localities of Jalisco because of its importance in the preparation of sauces. It is hypothesized that the management of planting density and fertilization application can improve the yield of this tomato. The objective of this study was to evaluate the leaf area and yield of P. angulata L. as a function of slow-release urea doses and planting densities, under open-field rainfed conditions. Nine treatments were evaluated, resulting from the combination of three planting densities and three fertilizer doses. The experimental design was randomized complete blocks with factorial arrangement. The data were analyzed with analysis of variance and the means of the treatments were compared with Tukey's test (p = 0.05). The relationship between yield and study variables was estimated with simple linear regressions. The results indicated that with 2.5 plants m-2 the highest yield was obtained (6.4 Mg ha-1); while with 140 units of slow-release urea the average yield was 5.76 Mg ha-1. The interaction effect showed that with densities of 2.0 and 2.5 plants m-2 and with 120 kg of slow-release urea, the highest fruit yields were obtained, 6.44 and 6.87 Mg ha-1. For each unit increase in the variables leaf area, leaf area index, number of fruits per plant and fruit weight per plant, fruit yield increased as well. The yield of P. angulata responded differently to planting densities and slow-release urea doses. The best yield could be obtained with the planting density of 2.5 plants m-2 and with the application of 30.4 g m-2 slow-release urea. [ABSTRACT FROM AUTHOR]

Kinetic study of the photo-assisted oxygen atom transfer reaction (OAT) using a dioxo-Mo complex anchored on TiO2, stimulated by light, was performed at ambient conditions using triphenylphosphine (PPh3) as a model molecule. The kinetic of the OAT reaction was studied with three catalytic systems: 4,4’-dicarboxylate-2,2’-bipyridine-dioxochloromolybdenum (MoO2L/TiO2), H2MoO4 (H2MoO4/TiO2) and molybdenum oxide (MoO3/ TiO2) anchored to TiO2. The MoO2L/TiO2 gives conversion higher than 90% and selectivity (to phosphine oxide) close to 100%. MoO3/TiO2 did not allow the oxo-transference, suggesting the importance of the bipyridine ligand as an electronic connector between MoO2L unit and TiO2. With the MoO2L/TiO2 system was observed that when the photonic flux increases, the quantum yield, and the OAT reaction rate increases. [ABSTRACT FROM AUTHOR]

Wilting of sugarcane is produced by a complex of Fusarium species, such as F. andiyazi and F. sacchari, which induce rotting of roots. In order to control this disease and reduce the use of fungicides, biological control has been proposed by means of antagonists of the genus Trichoderma. The objective of this study was to evaluate in vitro and in sugar cane plants the antagonistic capacity of strains of Trichoderma against F. andiyazi and F. sacchari. The hypothesis was that at least one strain of Trichoderma inhibits the growth in vitro of Fusarium and favors the development of the sugarcane plants. Eighteen strains of Trichoderma were isolated and their percentage of inhibition was determined on the mycelial growth of Fusarium species with the technique of dual culture in potato dextrose agar culture medium. The experimental design was completely randomized, with four replicates per treatment. The degree of antagonism of Trichoderma was evaluated at 13 d. The strains T2 and T8 which showed the best characteristics of antagonism were selected for the in vivo bioassay. For the evaluation in vivo, the sterile substrate was inoculated with F. andiyazi and F. sacchari, and the roots of sugarcane plants with strains T2 and T8 of Trichoderma in a design of randomized blocks, with three blocks and three replicates for each treatment. The variables evaluated were plant height (cm), fresh and dry root biomass (g), number and diameter of stems (mm) and root length (cm). The strains T2 and T8 were determined with morphological and molecular identification as T. asperellum and T. koningiopsis. The effect of these species on the sugarcane plants was beneficial, given that they increased plant height, along with length, wet and dry biomass of roots. [ABSTRACT FROM AUTHOR]

The objective of this work was to identify the agent associated with wilting disease and evaluate the incidence in nine commercial tomato genotypes: six genotypes with undetermined growth (Cid, Sun 7705, Moctezuma, Cuauhtémoc, Ramses and Aníbal) and three of determined growth (Palomo, Pony express and Toro). The genotypes were evaluated in four shadow mesh production systems: directly on soil, and tezontle substrate in 37x37, 40x40 and 40x45 cm polyethylene plastic bags. The wilt disease incidence was evaluated at 114 days in 3,476 plants. According to morphological characteristics in vitro in PDA medium and humid chamber, only one fungus of the Fusarium genus was isolated from 18/20 plants whereas Fusarium and Rhizoctonia solani were isolated in 2/20. The highest incidence was observed in genotypes Cid (20.1%), Moctezuma (22.4%) and Sun 7705 (29.7%) and the lowest on determined growth genotypes. The 37x37 cm bag production system had the highest wilting disease incidence (25.9%) with 74.3 t ha-1 yield; while in 40x45 cm bags the incidence was lowest (4.7%). In the four production systems, the lowest yield was obtained in Sun 7705 genotype ranging in 59.7 - 70.6 t ha-1. [ABSTRACT FROM AUTHOR]

Objective: To determine the level of environmental impact caused by an intensive aquaculture season of rainbow trout (Onchorhynchus mykiss) in floating cage systems in water nutrients and benthic macroinvertebrates in Lake Guamuez. Materials and methods. The study was developed in three areas of Lake Guamuez (two floating cage facilities and one control point). Three sampling stations with depths of 0, 10 and 20 meters were taken in each area, in order to perform measurements of total phosphorus, nitrites, nitrates and phosphates. Also, dives were carried out to a depth of approximately 20 meters, collecting sediment samples for the identification of macroinvertebrates. The environmental impact was evaluated by the relationship of the mentioned variables, using discriminant analysis and analysis of variance, previous verification of the statistical assumptions. Results. The nitrite, nitrate, phosphate and total phosphorus nutrients present significant differences (p<0.05) among all areas and only at some sampling depths. In addition, seven families of macroinvertebrates (Chironomidae, Thiaridae, Ampullariidae, Planaridae and Tubificidae indicative of contaminated and moderately contaminated waters and Hydrobiosidae and Hydrachnidae indicating good water quality) were collected. Conclusions. In the culture cages unlike the control point, higher nutrient content values were evidenced; the families of macroinvertebrates indicating contaminated or moderately contaminated water were also found. However, the results found are not found in risk limits for the lacustrine system or for the animals of culture. [ABSTRACT FROM AUTHOR]

The industrial production of xylitol is carried out with the chemical hydrogenation of D-xylose and it is a costly process. An alternative procedure is the fermentation of lignocellulosic residues with yeasts such as Debaryomyces hansenii (Zopf) Lodder and Kreger-van Rij. Therefore, the objective of this study was to evaluate the extraction of xylitol from sorghum straw, in detoxified and non-detoxified media. White sorghum straw [Sorghum bicolor (L.) Moench.], variety RB-Paloma, was hydrolyzed with H2SO4 at 2, 4 and 6 %; solid liquid ratio 1:6, 1:8 and 1:10; all treatments at 120 °C for 80 min. Those hydrolyzed were neutralized and used to evaluate the production of xylitol; culture media contained 30, 40 or 50 g L-1 xylose were inoculated with D. hansenii and incubated at 30 and 35 °C, 150 and 200 RPM for 96 h. In addition, the data were analyzed with ANDEVA and means tests (p £ 0.05). The maximum concentration of xylitol in the detoxified media was 28.8 g L-1 (40 g xylose, 35 °C, 200 rpm), and in non-detoxified, the maximum found was 29.23 g L-1 (30 g xylose, 35 °C, 150 rpm). The straw evaluated could be used to obtain xylose with a potential use in media for fermentation, and results also suggest that D. hansenii can metabolize xylose in the presence of acetic acid and furfural. [ABSTRACT FROM AUTHOR]

In the present work, the biosynthesis of titanium dioxide (TiO2) nanoparticles from extracts of Stevia rebaudiana leaves in semipolar media is shown. The reaction products were characterized by Fourier transformed infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Conversion of the precursor salt to the TiO2 compound was manifested by changes in the functional groups of the products. Thermal characterization showed residual contents greater than 40 %, indicating the formation of a thermally stable compound. Likewise, the presence of crystalline phases of TiO2 was evidenced. Therefore, it was considered that the phenolic compounds present in the extracts were used as reducing agents of the titanium precursor salt to obtain the TiO2 nanoparticles. However, the formation of TiO2 also depended on the extraction medium of Stevia rebaudiana. [ABSTRACT FROM AUTHOR]

Legumes are a traditional, sustainable and nutritious food for consumption due to their high protein content. Legume flour can be used to make food products or partially replace other flours, increasing their nutritional value, however they can modify the techno-functional and sensory properties, impacting the level of liking and acceptance. Nixtamalized corn tortillas were formulated with lentil (Lens culinaris), chickpea (Cicer arietinum) and Faba bean (Faba vicia L.) flour at 5, 10 and 15%. In a panel made up of 20 individuals using a 9-point hedonic scale, the general acceptance and level of liking of the descriptors color, smell, taste, texture and rollability were determined. The results were analyzed by Tukey's test with a significance of (P<0.05), observing that the greatest acceptance was for corn/lentil and corn/chickpea tortillas at 15% and corn/fava bean 5%, compared to corn/lentil tortillas. (15%) got the least acceptance. The level of liking for each descriptor was significantly correlated with the level of acceptance and the rollability and flavor of the tortilla were the main descriptors influencing the level of acceptance [ABSTRACT FROM AUTHOR]

In February 2012, a reproductive group of 60 adult blackbucks (Antilope cervicapra) from Veracruz, Mexico was relocated to hunting units in eastern and northeastern Mexico. Seven individuals died due to hemorrhagic parasitic, abomasitis and enteritis caused by Haemonchus spp., Setaria spp., and Trichostrongylids. Deaths were associated with hepatic necrosis, bilateral congestive distention of heart and fibrinonecrotic bronchopneumonia. Also Anaplasma marginale was identified. The blackbucks' population displayed a general mortality rate of 11.67%, where 25% of total male and 9.62% of total female died. The mortality was controlled by segregation of all remaining blackbucks and the treatment for internal and external parasites (biting flies and ticks). After the treatment, no fatality cases related to parasitosis were recorded. The results presented here exhibit the high relevance of parasitosis as possible factor risk in the survival of tis specie. [ABSTRACT FROM AUTHOR]

Peruvian laws on environmental quality have been analyzed by means of content analysis. Three levels have been involved: general objectives of ecosystem management, the nature of the ecosystem to be managed and the specific objectives and instruments used by the ecosystem management. Peruvian laws conceptualize the ecosystem almost as a complex adaptive system but the specific management objectives and the instruments used to manage the ecosystem do not take into consideration such approach; instead, management instruments seem to assume that the ecosystem is in steady state. These inconsistencies may be a consequence of nonsufficient epistemological reflection when the laws were elaborated or may be the consequence of a competitive process between the paradigm that sees nature as being in a steady state and the paradigm that sees nature as evolving permanently. [ABSTRACT FROM AUTHOR]

Forest litter emits CO2 into the atmosphere, but there are few studies on the subject and it is important to generate this information to improve inventories of greenhouse gases (GHGs). Methods to quantify this emission are performed in situ during long periods of measurements and others require the use of high cost instruments; some measure the loss of organic matter over time and others are indirect and are based on measurements dependent on weather conditions. The aim of this study was to generate a standardized operation protocol (PEO, its Spanish acronym) to measure the CO2 emission potential of in vitro litter using a manometric respirometer (OxiTop OC110®) in a maximum time of 10 d incubation. Litter samples were collected in a Quercus spp forest in Tequexquinahuac, Estado de Mexico, at the beginning of 2012. The experimental design was completely randomized, treatments were incubations (25 °C) with four litter moisture percentages (20, 40, 60 and 80% dry weight) and four sample sizes (5, 10, 20, 40 g), and each treatment was replicated three times. Based on the data ANOVA was performed and treatment means were compared with the Tukey test (p≤0.05). The response variables were: CO2 emission, CO2 emission rate and percentage of oxidized carbon compared to total carbon at the start of incubation. The optimum conditions for the measurement were 10 g sample and 60% humidity. Under these conditions the maximum CO2 emission was recorded (23554 mg CO2 kg-1) as well as the lowest standard deviation (331 mg CO2 kg-1), the lowest of the 16 treatments resulting from combining sample sizes and moisture percentage. In these conditions the percentage of carbon emitted compared to the initial carbon was the highest (5.26%). The measurement of respiration in such assay depends on the humidity of the sample and the availability of oxygen present in the system, which is the condition for determining the optimal operating environment using the OxiTop OC. The data generated by OxiTop are indicators of the potential emission of CO2 by different types of litter and have a similar value to that of the incubations performed to evaluate the potential mineralization of nitrogen. [ABSTRACT FROM AUTHOR]

Objective. To analyze the association between seropositivity to SARS-CoV-2 and chronic diseases in Mexican adults and older adults. Materials and methods. We used the 2020 National Health and Nutrition Survey on Covid-19 to evaluate the association of seropositivity to SARS-CoV-2 with high blood pressure, type 2 diabetes, body mass index, elevated LDL-c, low HDL-c, high total cholesterol, and hypertriglyceridemia. Results. We observed a higher seropositivity at higher body mass index levels. In adjusted models, seroprevalence was 25% higher among adults with obesity compared to those of normal weight (PR: 1.25 95%CI: 1.08,1.46). We did not observe any association between seropositivity and other chronic diseases in adults or older adults. Conclusions. Adults with obesity could be at increased susceptibility of SARS-CoV2 infection. This observation needs to be confirmed through longitudinal studies. We did not find evidence of an association with other chronic diseases. [ABSTRACT FROM AUTHOR]

The high concentrations of heavy metals in groundwater used for irrigation have the potential of causing physiological damage in agricultural crops, as well as reducing the quality and yield of harvests. Furthermore, there are effects on human health due to the consumption of contaminated products. The objective of the present study was to determine the concentration of Cd, Hg, Pb, As and B in the groundwater for agricultural use in the municipalities of Autlán de Navarro and Zocoalco de Torres, Jalisco, Mexico, both with high agricultural activity. The study was conducted from February to April and from August to November of 2017, and 24 samples of groundwater were analyzed per season. The evaluations were as follows: potential of hydrogen (pH) and electric conductivity (C.E.); quantification of the heavy metals cadmium (Cd), mercury (Hg), lead (Pb) and the metalloid arsenic (As); content of boron (B) in the groundwater given its nutrimental and toxic importance. The heavy metals were determined by atomic emission spectrometry and the concentrations found were compared with the guidelines of the NOM-001-ECOL-1996. On the average, electric conductivity was 665 mS cm-1 and the pH 7.7, values that do not represent restriction with respect to the use of agricultural irrigation water. In the heavy metals, the Hg exceeded in 100% of the samples the maximum limits established with an average concentration of 0.14 mg L-1, the metalloid As exceeded in 16% of the samples the maximum limit with an average concentration of 0.13 mg L-1, but Cd, Pb and B did not surpass the values established as permissible limit for the use of water in agricultural irrigation. [ABSTRACT FROM AUTHOR]

Most studies in Mexico on the decomposition of crop roots are carried out on small surfaces and under controlled conditions; this fact limits the regional information. In contrast, local soil knowledge provides information that allows to know the distribution and agronomic management of soil in larger areas. The objective was to determine the rate of decomposition of maize roots < 2 mm in lands with different type and agricultural management by combining technical and local soil knowledges. The study was conducted in the Vega de Madero ejido, Hidalgo. Land classes were determined through field trips with farmers work, and the plots were selected through interviews with local producers. The rate of decomposition was obtained from ingrowth cores installed in the plots. In addition, bulk soil samples were taken to determine their edaphic properties and their soil classification. Six treatments (plots) were selected in three land classes (clayey black, BN, clayey brown, BP, and clayey with white Tepetate, BB) and two agronomic managements (monoculture and crop rotation). Experimental design was completely randomized, and data were analyzed with ANOVA and Tukey test to compare means. Vertisols and Inceptisols (Soil Taxonomy) or Vertisols and Regosols (WRB) occur in the study area. The local producers recognize three speeds of decomposition based on the presence or absence of fine and thick roots, which matched the values calculated in the in-growth cores in the field. The highest mortality rate in decreasing order was in BN (0.047), BB (0.024) and BP (0.011) with irrigation and in BP (0.001) in rainfed conditions. The interaction between local and technical soil knowledge allowed identifying and calculate speeds and rates of decomposition of roots with different crop management. [ABSTRACT FROM AUTHOR]

Objective: To determine the presence of Rickettsia typhi in synanthropic rodents captured in the rural community of Bolmay, Yucatan, Mexico, an area with history of murine typhus cases. Materials and methods. Thirty Mus musculus, 6 Rattus rattus and 1 Heteromys gaumeri were examined. Total DNA was obtained of rodent's spleen. The identification of Rickettsia typhi was performed through the fragment's amplification of the htrA (17-kDa gene protein) by endpoint PCR. The positive products were purified and sent for sequencing and analysis with the BLAST tool. Results. Rickettsial DNA was identified in 27% (10/37) of the rodents: seven M. musculus and 3 R. rattus. The alignment analyses obtained identity and coverage percentages of 97 - 99% for R. typhi. Conclusions. The present study suggests the participation of synanthropic rodents in the murine typhus cycle in the region. We described the first molecular evidence of R. typhi in M. musculus of Yucatan, Mexico. [ABSTRACT FROM AUTHOR]

Data from 241 interviews collected in 2013 was analyzed to characterize populations of pigs (Mexican Hairless Pig (MH), Cuino Pig (CU) and Crossbred Pig (UD)). Variables were body weight (BW), head length (HL), body length (BL), thoracic perimeter (CG), height at withers (HW), croup width (RW), number of nipples (TC), dense or sparse hair (HD), presence or absence of tusks (TU), short or long snout (ST), upright or floppy ears (ER), calm or restless temperament (TM), proportionality index (PI), body index (BI) and relative weight index (RWI). Analyses were carried out with GLM and GENMOD of SAS. Models included state and population. Population was significant (P<0.05) for BW, BL, CG, HW, RW, TU, TM, PI, BI and RWI. Coefficients of variation (VC) showed the minor and major values for BW (18.8 %) and CG (27.8 %). VC were 13.0, 14.6 and 45.8 % for PI, BI and RWI. Least squares means for MH, CU and UD were: 48.06±6.17a, 35.93±3.04b and 61.11±7.42a kg (BW); 77.81±3.65ab, 69.56±2.02a and 88.52±4.93b cm (BL); 80.55±3.98ab, 71.72±2.20a and 93.23±5.37b cm (CG); 56.88±2.45ab, 51.26±1.36a and 60.32±3.31b cm (HW); 57±4a, 71±19b and 62±34a % (HD); 68±31ab, 70±14a and 61±27b% (TU); 65±30a, 56±12b and 62±3a% (TM). The MH and UD populations were similar in morphometry and different from the CU population. The CU population showed lower weight, smaller size and calmer temperament. The characterization of these populations is important for designing strategies for their conservation and efficient use. [ABSTRACT FROM AUTHOR]

The objective was to evaluate some morphological characteristics of backyard turkeys (n=248) coming from 126 rural production units located in 75 municipalities of 24 States of the Mexican Republic. The statistical model included sex, state, and municipality within state. The three explanatory variables affected all the response variables (P<0.01), except municipality, which did not affect breast circumference (P>0.05). Male turkeys had greater (P<0.001) body length (10.7 cm more), wingspan (11.4 cm more), breast circumference (13.8 cm more), shank length (2.5 cm more), body weight (2.5 kg more), stockiness (9.0 percentage units more) and massiveness (2.8 percentage units more) than female turkeys. Body weight showed to be highly correlated phenotypically (P<0.01) with breast circumference in both males (r=0.74) and females (r=0.71). Body length was lowly correlated with shank length (r=0.25; P<0.01) in males, but it was not correlated with shank length in females (r=0.05; P>0.05). Body weight increased 143 g in males (P<0.01) and 113 g in females (P<0.01) for each centimeter increment in breast circumference. The predominant colors in the plumage, skin and tarsus were black, white and brown, respectively. The Mexican backyard turkey presented significant sexual dimorphism and strong phenotypic correlation between breast circumference and body weight. [ABSTRACT FROM AUTHOR]