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Montecillo, Mexico

Marin S.M.A.,Autonomous University of Baja California | Spinola A.G.,Postgraduate College | Cano A.F.,Technical University of Cartagena | Ortiz R.S.,Autonomous University of Baja California | And 2 more authors.
African Journal of Agricultural Research | Year: 2011

We evaluated the mode of decomposition in relation to biochemical quality of plant residues and land use. Alfisols under different uses (woodland, grassland and cultivated soils) mixed with alfalfa (Medicago sativa L.) and wheat straw (Triticum aestivum L.) in doses of 10 t ha -1 (dry weight) were incubated in laboratory, in triplicate. CO 2 emitted from soil was measured after 20, 40, 60, and 80 h of incubation, and the amount of released C was calculated (mg C g -1 soil). The difference between the amount of C added by the plant residue and C liberated as CO 2, was named residual C. The C loss was greater and residual C retained was lower (p<0.05) for Alfisols where alfalfa was applied than for those were wheat straw was added, which was a function of the biochemical composition differences between the alfalfa and wheat straw residues. Regarding the land use, residue C loss was lower (p<0.05) in woodland (Haematoxylon campechianum and Bucida buceras) soils (rates from-0.12 to-1.02 μg g -1 /day), and greater in grassland (Gramineae) and cultivated soils (Sorghum vulgare and Yucca sp.) (rates from-0.28 to-1.37 μg g -1 /day). We conclude that the C loss, by decomposition, increases in order of woodland > grassland > cultivated soils, and less residual C is retained. © 2011 Academic Journals. Source

Taboada-Castro M.M.,University of La Coruna | Rodriguez-Blanco M.L.,University of La Coruna | Dieguez A.,University of La Coruna | Palleiro L.,University of La Coruna | And 2 more authors.
Communications in Soil Science and Plant Analysis | Year: 2015

Monitoring was conducted in a basin with a history of agricultural pollution (mainly due to the spreading of livestock slurry) to evaluate the response of stream water ion concentrations to the change from agricultural land use to forest. We measured pH, electrical conductivity (EC), and major dissolved elements [phosphate (PO4) phosphorus (P), nitrite (NO2) nitrogen (N), nitrate (NO3) N, ammonium (NH4) N, silicon (Si), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), sulfate (SO4), and chloride (Cl)] in the stream water during the period 1997–2002 at irregular time intervals. Median values were significantly greater in the agricultural period than in the forest period (P < 0.05). Median pH values remained slightly acidic (5.8–6) for both land uses. NO3-N was the dominant form of dissolved inorganic nitrogen (DIN) under both land uses (agricultural use: 80 percent; forest use: 98 percent. In the forest period, the median PO4-P and NH4-N concentrations were reduced by 95 percent compared to the agricultural period. The median NO2-N and K concentrations decreased by 83 percent and 70 percent, respectively, whereas NO3-N, Cl, Na, and Si showed minor differences (decreases of 15–20 percent). These findings are consistent with the poor agricultural management practices that have been developed in the basin, especially as regards the application of slurry. © , Copyright © Taylor & Francis Group, LLC. Source

Zhao T.-D.,Postgraduate College
Chinese Journal of Cancer Prevention and Treatment | Year: 2012

To investigate the effect of euphorbia fischeriana steud (LDE) on apoptosis and expression of Caspase-9 mRNA in Lewis lung carcinoma. Lewis cells were exposed with LDE of different concentration (0.2, 0.4 and 0.8 mg/mL) for 24 hours. Annexin-V/PI double label staining was applied to detect the change of apoptosis rate. Flow cytometry was applied to detect the change of cell cycle. The mRNA level of Caspase-9 was detected by Real-time PCR. By Annexin-V/PI double label staining to examine apoptosis of control and low, middle and high LDE dose group (0.2, 0.4 and 0.8 mg/mL), and the rate respectively was (0.331 ± 0.012)%, (8.27 ± 0.067)%, (28.19 ± 0.270)%, (32.96 ± 0.14)%. Flow cytometry showed that the G0/G1 phase rate of the control and low, middle and high LDE dose group were (50.3 ± 0.77) %, (44.2 ± 1.82)%, (34.1 ± 1.56)%, (25 ± 0.72)%. Real-time PCR showed that Caspase-9 mRNA expression level of the control and LDE group were 1.00 and 1.64. LDE can effectively induce apoptosis of Lewis cells through blocking the cell cycle at G0/G1 phase and increase the expression of Caspase-9 mRNA level. Source

Sharma N.K.,Postgraduate College | Tiwari S.P.,Poorvanchal University | Tripathi K.,Banaras Hindu University | Rai A.K.,Banaras Hindu University
Journal of Applied Phycology | Year: 2011

Cyanobacteria (blue-green algae) are widely distributed Gram-negative oxygenic photosynthetic prokaryotes with a long evolutionary history. They have potential applications such as nutrition (food supplements and fine chemicals), in agriculture (as biofertilizer and in reclamation of saline USAR soils) and in wastewater treatment (production of exopolysaccharides and flocculants). In addition, they also produce wide variety of chemicals not needed for their normal growth (secondary metabolites) which show powerful biological activities such as strong antiviral, antibacterial, antifungal, antimalarial, antitumoral and anti-inflammatory activities useful for therapeutic purposes. In recent years, cyanobacteria have gained interest for producing biofuels (both biomass and H2 production). Because of their simple growth needs, it is potentially cost-effective to exploit cyanobacteria for the production of recombinant compounds of medicinal and commercial value. Recent advances in culture, screening and genetic engineering techniques have opened new ways to exploit the potential of cyanobacteria. This review analyses the sustainability of cyanobacteria to solve global problems such as food, energy and environmental degradation. It emphasizes the need to adopt multidisciplinary approaches and a multi-product production (biorefinery) strategy to harness the maximum benefit of cyanobacteria. © 2010 Springer Science+Business Media B.V. Source

Gonzalez E.G.,National Polytechnic Institute of Mexico | Panteleeva O.V.,Postgraduate College | Olvera A.L.R.,Postgraduate College
European Journal of Scientific Research | Year: 2011

In this paper, a general model is proposed to extend generalized linear models to non-monotonic link functions. In order to determine the best model, different link function families are analysed, and through AIC, the best model is chosen. Moreover, using asymptotic properties of maximum likelihood estimates are calculated with confidence intervals and hypothesis tests for each of the parameters. Lastly, one example of regression extension is proposed for the Bernoulli distribution applied to in vitro germination of Leucocoryne coquimbensis seeds. © EuroJournals Publishing, Inc. 2011. Source

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