This work examines the influence of sodium montmorillonite on the chemical transformations undergone by two nucleosides (cytidine
and adenosine) in simulated primitive Earth conditions. The aim of this study is to test the hypothesis of a protective role
of solid surfaces like clay for organic compounds adsorbed on them, when exposed to external sources of ionizing radiation
(γ-ray). The results showed this role of protection: the decomposition of nucleosides was lower when adsorbed on a clay mineral.
It was also found that a purinic nucleoside (more than pirimidinic) was quickly adsorbed on clay at low pH and desorbed in
neutral or lightly basic aqueous solutions. For analysis of samples, different techniques were used: X-ray diffraction, UV–Vis
spectroscopy, and HPLC.
Hybrid rice varieties have clearly shown a 1–1.5 t/ha yield advantage over semi-dwarf inbred high-yielding varieties in China and other countries. No information about the performance of hybrid rice varieties in rice-producing European countries been reported, however. Three previously selected Indica hybrid varieties from China (SYRC-86, SYRC-89 and SYRC-90), and two Indica check varieties (L-202 and Doongara) were evaluated in southern Spain. Various agronomic performance indicators including days to heading, plant height, grain moisture at harvest, yield components, grain yield and milling quality were recorded. Plant height and 1000-grain weight were found to be significantly greater in the hybrids, the yields of which exceeded those of the high-yielding check varieties by 10–20%. By contrast, head rice recovery was 7–10% lower in the hybrids than in the check varieties. The optimum seeding rate for the hybrids was about 75–90 kg/ha.
Authors:S. Reyes-de Vaaben, A. Aguilar, F. Avalos, and L. Ramos-de Valle
The effect of four nucleating agents on the crystallization of isotactic polypropylene (iPP) was studied by differential scanning
calorimetry (DSC) under isothermal and non-isothermal conditions. The nucleating agents are: carbon nanofibers (CNF), carbon
nanotubes (CNT), lithium benzoate and dimethyl-benzylidene sorbitol.
Avramișs model is used to analyze the isothermal crystallization kinetics of iPP.
Based on the increase in crystallization temperature (Tc) and the decrease in half-life time (τ½) for crystallization, the most efficient nucleating agents are the CNF and CNT, at concentrations as low as 0.001 mass%.
Sorbitol and lithium benzoate show to be less efficient, while the sorbitol needs to be present at concentrations above 0.05
mass% to even act as nucleating agent.
Authors:Dora Romero-Salas, Cosme Alvarado-Esquivel, Gladys Domínguez-Aguilar, Anabel Cruz-Romero, Nelly Ibarra-Priego, Carolina Barrientos-Salcedo, Mariel Aguilar-Domínguez, Rodolfo Canseco-Sedano, Luz Teresa Espín-Iturbe, Luis Francisco Sánchez-Anguiano, Jesús Hernández-Tinoco, and Adalberto A. Pérez de León
We aimed to determine the seroprevalence of infection with Neospora caninum, Leptospira, and bovine herpesvirus type 1 and risk factors associated with these infections in water buffaloes in Veracruz State, Mexico. Through a cross-sectional study, 144 water buffaloes (Bubalus bubalis) raised in 5 ranches of Veracruz were examined for anti-N. caninum and anti-bovine herpesvirus type 1 antibodies by enzyme immunoassays, and anti-Leptospira interrogans antibodies by microscopic agglutination test.
Of the 144 buffaloes studied, 35 (24.3%) were positive for N. caninum, 50 (34.7%) for Leptospira, and 83 (57.6%) for bovine herpes virus. The frequencies of leptospiral serovars in buffaloes were as follows: 18.7% for Muenchen (n = 27), 10.4% for Hardjo LT (n = 15), 9.0% for Pyrogenes (n = 13), and 4.8% for Icterohaemorrhagiae (n = 7). Seropositive buffaloes were found in all 5 ranches studied. Logistic regression showed that cohabitation of buffaloes with cows was associated with infection with Leptospira (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.04–4.5; P = 0.03) and bovine herpesvirus (OR, 12.0; 95% CI, 4.0–36.2; P >; 0.01).
This is the first study that provides serological evidence of N. caninum, Leptospira, and bovine herpesvirus type 1 infections in water buffaloes in Mexico. Our findings could be used to enhance preventive measures against these infections.
Authors:E. Herrera Peraza, O. Rizo, M. Montero Cabrera, A. Hernández, R. Folgar, M. Cabrera, O. Aguilar, M. Guevara, I. Pellon, R. López Duménigo, G. González, and M. López Reyes
This paper explains chronologically the implementation of thek0-standardization and other parametric methods in Cuba. Fundamental and applied results in the determination of the most important
parameters are obtained, using the IBR-2 at Dubna and Triga Mark III at Mexico reactor facilities. Some modifications in the
Stoughton-Halpering convention, and its comparison with the modified Westcott and Høgdahl method are presented. The application
of the described methods at the CS-ISCTN low flux facility, using the big samples techniques, is presented.
Authors:L. Gomez-Pando, J. Jimenez-Davalos, A. Eguiluz-De La Barra, E. Aguilar-Castellanos, J. Falconí-Palomino, M. Ibañez-Tremolada, M. Aspiolea, and J. Lorenzo
Although barley is extensively grown in the Peruvian highlands as a food crop, agronomic and quality performance are poor. In addition, there are few reports of the successful application of modern technologies, such as doubled haploidy, in developing nations. Double-haploid technique was used to obtain barley cultivars better suited to this environment. From barley crosses Ya/LM94, B16/LM94 and B12/LM94, four promising double-haploid lines were evaluated in the highland Acobamba Farming Community along with their parents and two control cultivars (PPch, UNA80). Double-haploid lines, Ya/LM94-PC27 and B12/LM94-PC34, were the most agronomically acceptable. Here we describe their potential economic benefits for Acobamba farmers. Both reached the best quality grade based on hectoliter mass, and should therefore obtain the highest market price, and provide the best incomes, gains, and profitability rates. In comparison, PPch and UNA80 if grown would be unprofitable, and LM94 would be markedly less profitable. Use of the double-haploid technique in our breeding program was estimated to cut research expenses by 26%, due to the shorter time for cultivar improvement.
Authors:F.A. Rodríguez-Zaragoza, M. Ortiz, F. Berrios, L. Campos, A. de Jesús-Navarrete, J. Castro-Pérez, A. Hernández-Flores, M. García-Rivas, F. Fonseca-Peralta, and E. Gallegos-Aguilar
Banco Chinchorro is the largest reef in the Mexican Caribbean. Historically, spiny lobster, queen conch and over 20 other reef species have been exploited here. Multispecies intervention management from an ecosystem perspective has been developed in this area; however, an assessment of the effects of such practices on ecosystem health is required. Five quantitative trophic models were constructed using Ecopath with Ecosim. The results show that, in terms of biomass, benthic autotrophs are the dominant group in all communities. Ecosystem Network Analysis indices showed that Cueva de Tiburones was the most mature, developed, complex and healthy subsystem, but, El Colorado and La Baliza were the subsystems most resistant to disturbances. The fisheries mainly concentrate on primary (La Baliza and Cueva de Tiburones sites) and secondary consumers (La Caldera, Chancay, and El Colorado). The greatest propagation of direct and indirect effects, estimated by Mixed Trophic Impacts and Ecosim simulations, were generated by the benthic autotrophs, small benthic epifauna, benthic-pelagic carnivorous fish and benthic carnivorous fish, among others. In contrast, the System Recovery Time showed different patterns among subsystems, indicating several compartments that reduce resilience. Considering the structure, dynamics, trophic functioning and ecosystem health of Banco Chinchorro, its ecological heterogeneity highlights the need for the design of a specific (by subsystem) management strategy, particularly because different species or functional groups present greater sensitivity to human interventions in each community.