870 research outputs found
Toxicity of several d-endotoxins of Bacillus thuringiensis against Helicoverpa armigera (Lepidoptera: Noctuidae) from Spain
Toxicity and larval growth inhibition of eleven insecticidal proteins of Bacillus thuringiensis were evaluated against neonate larvae of Helicoverpa armigera, a major pest of important crops in Spain and other countries, by a whole-diet contamination method. The most active toxins were Cry1Ac4 and Cry2Aa1, with LC50 values of 3.5 and 6.3 μg/ml, respectively. At the concentrations tested, Cry1Ac4, Cry2Aa1, Cry9Ca, Cry1Fa1, Cry1Ab3, Cry2Ab2, Cry1Da, and Cry1Ja1, produced a significant growth inhibition, whereas Cry1Aa3, Cry1Ca2, and Cry1Ea had no effect
Structural study of the compounds formed in the reactions of FeCl3 6H2O with Ni(OH)2 in the presence of dithiolenes HSRSH (R = C6H2Cl2 or C6H4)
Fragility Curves for Thin-Walled Cold-Formed Steel Wall Frames Affected by Ground Settlements Due to Land Subsidence
Land subsidence phenomenon due to ground water withdrawal is a current problem in many places around the world, particularly in the shallows of Mexico. This causes ground differential settlements that affect structures, mainly dwellings and buildings based on reinforced concrete and masonry. Eventually, these structural materials do not exhibit an adequate performance beyond a certain level of angular distortion. This work presents the results about a study regarding the performance of thin-walled cold-formed steel wall frames with different sheathing systems affected by angular distortions simulating ground differential settlements due to land subsidence. The wall frames are composed by vertical (studs) and horizontal elements (tracks), with different sheathing systems: polystyrene, OSB, gypsum and calcium silicate. By means of experimental testing of wall frames subjected to monotonic lateral loads, the rotational stiffness was obtained for the wall frames with polystyrene. Likewise the rotational stiffness of the other wall frame systems was calculated based on the data provided by other author’s publications. On the other hand, by means of numerical simulation, all the wall frame systems were modeled in structural analysis software, calibrating them based on the rotational stiffness. Also, the moment-rotation curves were calculated for the studs and tracks based on the direct strength method. A non-linear static pull down analysis was performed producing several degrees of angular distortion simulating ground settlements for all the wall frames sheathing systems. With the data acquired fragility curves were calculated according three levels of damage for the wall frames with different sheathing system
Decomposition and nitrogen mineralisation of two wild lupins (Leguminosae) species with potential as green manures
The amount of biomass produced by various native species of genus Lupinus (L.) growing in Mexico ranges from 2.9- 8.2 Mg/ha of dry matter, which can add up to 200 kg/ha of N to soil as green manure. However, information is scarce on the decomposition and mineralisation this biomass in the soil. The above-ground decomposition and N mineralisation of Lupinus mexicanus Cerv. ex Lag. and Lupinus rotundiflorus M.E. Jones species from Mexico using fine-mesh litter bags was evaluated. Litter bags containing 5 g of above-ground air-dried biomass at the vegetative and flowering stages were buried at a depth of 20 cm. Were dug up every 3 weeks over the course of 4 months, dried and re-weighed to determine the lost mass and total N by the Kjeldahl method. The largest decrease in residue mass occurred during the first 3 weeks of incubation. However, the lost mass was higher in younger green manure (75 days old) than in older plants (85 days old) after 18 weeks of exposure in the field. It was found that 60-75% of the total N in the plant material was released in the first 6 weeks. In L. rotundiflorus green manure, it was found that 79.14% of the initial N in the vegetative stage and 77.6% of N in the flowering stage was released 18 weeks after litter bag installation, whereas L. mexicanus were 74.6% and 74.7%, respectively. It was found that both decomposition and N mineralisation occurred quickly in the green manures evaluated
Decolorization and detoxification of synthetic dyes by mexican strains of trametes sp
Laccases have attracted a great deal of interest because of their remarkable ability for the degradation of synthetic dyes present in wastewaters. New laccase producing sources with robust operational and functional properties are being continuously explored. In this work, the potential for the decolorization and detoxification of synthetic dyes was evaluated in two Mexican strains of the genus Trametes. The decolorization capacity of Trametes maxima LE130 and Trametes sp. LA1 was tested in solid and liquid media. The phytotoxicity of the degradation products was determined using Raphanus sativus and Pisum sativum seeds. In solid media, both strains showed a higher decolorization capacity (p ≤ 0.05) than Phanerochaete chrysosporium ATCC 24725, which is known to be very efficient in lignin and dye-degradation. They produced laccase as the main ligninolytic enzyme; T. maxima LE130 secreted a single isoform of 43.9 kDa, while Trametes sp. LA1 produced three isoforms of 67.3, 58.6 and 52.7 kDa, respectively. Trametes sp. LA1 culture fluids were capable of decolorizing and detoxifying chemically diverse dyes (anthraquinonic dye Remazol Brilliant Blue R, azoic Reactive Black 5 and triphenylmethane Crystal Violet) without the addition of redox mediators. Therefore, this could be considered as a new laccase source which could be potentially competitive in the bioremediation of dye-containing wastewaters.Fil: Levin, Laura Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Hernández Luna, Carlos E.. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Niño Medina, Guillermo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: García Rodríguez, Juan Pablo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: López Sadin, Iosvany. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Méndez Zamora, Gerardo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Gutiérrez Soto, Guadalupe. Universidad Autonoma de Nuevo Leon.; Méxic
Probing leptogenesis
The focus of this paper lies on the possible experimental tests of leptogenesis scenarios. We consider both leptogenesis generated from oscillations, as well as leptogenesis from out-of-equilibrium decays. As the Akhmedov-Rubakov-Smirnov (ARS) mechanism allows for heavy neutrinos in the GeV range, this opens up a plethora of possible experimental tests, e.g. at neutrino oscillation experiments, neutrinoless double beta decay, and direct searches for neutral heavy leptons at future facilities. In contrast, testing leptogenesis from out-of-equilibrium decays is a quite difficult task. We comment on the necessary conditions for having successful leptogenesis at the TeV-scale. We further discuss possible realizations and their model specific testability in extended seesaw models, models with extended gauge sectors, and supersymmetric leptogenesis. Not being able to test high-scale leptogenesis directly, we present a way to falsify such scenarios by focusing on their washout processes. This is discussed specifically for the left-right symmetric model and the observation of a heavy WR, as well as model independently when measuring L = 2 washout processes at the LHC or neutrinoless double beta decay.Fil: Chun, E. J.. Korea Institute For Advanced Study; Corea del SurFil: Cvetic, G.. Universidad Técnica Federico Santa María; ChileFil: Dev, P. S. B.. Washington University in St. Louis; Estados UnidosFil: Drewes, Alejandro Marcelo. Technische Universitat München; Alemania. Université Catholique de Louvain; BélgicaFil: Fong, C. S.. Universidade de Sao Paulo; BrasilFil: Garbrecht, B.. Technische Universitat München; AlemaniaFil: Hambye, T.. Université Libre de Bruxelles; BélgicaFil: Harz, J.. Institut Lagrange de Paris, Sorbonne Universitès; Francia. Centre National de la Recherche Scientifique; FranciaFil: Hernández, P.. Cern - European Organization For Nuclear Research; Suiza. Universidad de Valencia; EspañaFil: Kim, C. S.. Department Of Physics And Ipap, Yonsei University; Corea del SurFil: Molinaro, E.. University Of Southern Denmark; DinamarcaFil: Nardi, E.. Laboratori Nazionali Di Frascati; ItaliaFil: Racker, Juan Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Rius, N.. Universidad de Valencia; EspañaFil: Zamora-Saa, J.. Joint Institute For Nuclear Research; Rusi
Mexican oregano essential oils given in drinking water on performance, carcass traits, and meat quality of broilers
The objective of this study was to evaluate the effects of 2 Mexican oregano essential oils (MOO), from Poliomintha longiflora Gray (PLG) and Lippia berlandieri Schauer (LBS), in drinking water (DWt) on the performance, slaughter variables, and meat quality of broilers over a 40 D period of growth. A total of 180 non-sexed Ross-308 broilers (1-day-old) were randomly assigned to 3 treatments with 6 replications each (10 birds per replicate): CON = DWt control (without MOO); PLG = DWt + 400 mg/L of PLG; and LBS = DWt + 400 mg/L of LBS. The CON, PLG, and LBS broilers body weights were similar (P > 0.05) at all times. Feed intake (FI) was different by treatment (P 0.05), although WG for CON was slightly higher. In CON broilers,
slaughter weight was highest (P < 0.05), but thigh yield was lowest (P < 0.05). The CON and PLG treatments were lower (P < 0.05) in thigh and leg cooking losses. The PLG treatment presented the highest values (P < 0.05) for breast-meat redness, saturation index, shear force, odor, taste, and overall sensory acceptability. The LBS was higher (P < 0.05) for breast-meat shear force, cohesiveness and resilience, but lower (P <0.05) for sensory attributes. Mexican oregano essential oils at 400 mg/L can serve as natural alternative additives in DWt to improve broiler production and meat quality
Physical and chemical properties of soils irrigated with vinasses for the cultivation of sugarcane (Saccharum spp.) in the central region of Veracruz, Mexico
Objective: To evaluate the physical and chemical properties of a soil with vinasse application (two years) (V), compared to a soil without vinasse (W/V).
Design/methodology/approach: In both agroecosystems, the evaluated parameters were texture, pH, electrical conductivity (EC), organic matter (OM), phosphorus (P), potassium (K), nitrates (NO3) and total nitrogen (TN) according to standardized methods in NOM-021-SEMARNAT-2000.
Results: There were no significant changes (p>0.05) in the pH and electrical conductivity, however, the application of vinasse significantly increased (p˂0.05) the content of TN (1.52%), K (112.00 mg L-1) and OM (4.52%) in relation to soils W/V (0.78%, 25.60 mg L-1, 7.40 mg L-1, 2.75%, respectively).
Limitations on study/implications: In Veracruz state, there are few studies that allow knowing the contributions, and physical and chemical effects on soils irrigated with vinasses.
Findings/conclusions: Even though, the vinasse used showed a positive effect on the physical and chemical characteristics of the soil (V), the mineral fertilization program must be reformulated to increase the concentration of potassium and phosphorus in soils with silt loam texture. In addition, it is recommended to adjust and normalize the dose of N that vinasse can provide instead of conventional fertilizers.
Keywords: Soil fertility, sugarcane, vinasses.Objective: To evaluate the physical and chemical properties of a soil irrigated with vinasse for two years (+V), compared with a soil without vinasse (-V) application.Design/Methodology/Approach: The following parameters were evaluated for both agroecosystems: texture, pH, electrical conductivity (EC), organic matter (OM), phosphorus (P), potassium (K), nitrate (NO 3 ), and total nitrogen (TN). The evaluation followed the standardized methods established in NOM-021-SEMARNAT-2000.Results: There were no significant changes (p &gt; 0.05) in the soil’s pH and electrical conductivity. However, the application of vinasse significantly increased (p &lt; 0.05) the concentrations of TN (1.52%), K (112.00 mg L -1 ), and OM (4.52%) in relation to soils - V (0.78%, 25.60 mg L -1 , 7.40 mg L-1 , and 2.75%, respectively).
Study Limitations/Implications: There are few studies about the contributions and the physical and chemical effects of soil irrigation with vinasses in the State of Veracruz.Findings/Conclusions: Even though vinasse had a positive effect on the physical and chemical characteristics of the soil, the mineral fertilization program must be reformulated to increase the K and P concentration in soils with silt loam texture. In addition, we recommend adjusting and normalizing the dose of N that vinasse can provide to complement conventional fertilizers
Genomic prediction models for grain yield of spring bread wheat in diverse agro-ecological zones
Genomic and pedigree predictions for grain yield and agronomic traits were carried out using high density molecular data on a set of 803 spring wheat lines that were evaluated in 5 sites characterized by several environmental co-variables. Seven statistical models were tested using two random cross-validations schemes. Two other prediction problems were studied, namely predicting the lines’ performance at one site with another (pairwise-site) and at untested sites (leave-one-site-out). Grain yield ranged from 3.7 to 9.0 t ha−1 across sites. The best predictability was observed when genotypic and pedigree data were included in the models and their interaction with sites and the environmental co-variables. The leave-one-site-out increased average prediction accuracy over pairwise-site for all the traits, specifically from 0.27 to 0.36 for grain yield. Days to anthesis, maturity, and plant height predictions had high heritability and gave the highest accuracy for prediction models. Genomic and pedigree models coupled with environmental co-variables gave high prediction accuracy due to high genetic correlation between sites. This study provides an example of model prediction considering climate data along-with genomic and pedigree information. Such comprehensive models can be used to achieve rapid enhancement of wheat yield enhancement in current and future climate change scenario
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