Comprensión conceptual de estadística y métodos de decisión utilizando herramientas de gamificación para la adquisición de competencias en los grados de ciencias económicas y empresariales

El objetivo general del proyecto es mejorar la motivación y la actitud de los alumnos de los grados de ciencias sociales hacia las materias cuantitativas, así como su participación activa en el proceso de enseñanza-aprendizaje, individual y en grupo, con la finalidad última de incrementar su nivel de competencias y rendimiento

Monomer composition and sequence of sodium alginate extracted at pilot plant scale from three commercially important seaweds from Mexico

The marine waters of the Baja California peninsula (Mexico) are a rich source of brown seaweeds with a great potential for exploitation. For that reason, Sargassum sinicola, Eisenia arborea, and Macrocystis pyrifera collected from different locations were subjected to extraction of sodium alginate using a pilot-plant scale process developed in our facilities. The composition and sequence parameters of the recovered alginate were studied by infrared and nuclear magnetic resonance spectroscopy. The spectral analysis of the products revealed that sodium alginate from S. sinicola contains a greater proportion of guluronate monomers (64%) than that from E. arborea (48%), and M. pyrifera (38%). Computation of the frequencies of diads and triads indicated that the alginate from S. sinicola was constructed by intercalated guluronate-blocks of 14 residues in length. In contrast, the length of the G-block in the alginates from E. arborea and M. pyrifera were 7 and 4 residues, respectively. The results show that S. sinicola, E. arborea, and M. pyrifera are sources of sodium alginate with different mannuronate/guluronate ratios, as well as a varied building-block length. In consequence, aqueous dispersions of sodium alginate from the three studied species are expected to exhibit different physical properties

Chemical Constituents of Eisenia Arborea Areschoug from Baja California Sur, México

Samples of Eisenia arborea from Baja California Sur, México collected in November 2002 and March 2003 were studied. The following parameters were analyzed separately from blades and stipes: moisture, ash, mannitol, fat and crude fiber. Alginate was isolated and the following quality parameters were obtained: yield (22.4-23.3%), color (> 4) and viscosity (793- 2,210 m Pa s in 1% solution). No significant differences were obtained between two months, except for viscosity and crude fiber. Significant differences were obtained when comparing blades and stipes in viscosity, mannitol, ash and fat, while for yield, moisture and crude fiber no significant differences were obtained. FTIR spectroscopy showed that alginate from E. arborea contained similar amounts of mannuroic and guluronic acids

Screening of extracts of algae from Baja California Sur, Mexico as reversers of the antibiotic resistance of some pathogenic bacteria

Sixty ethanol extracts of marine flora of Baja California Sur (Mexico) were screened to evaluate the reversing effect of the bacterial resistance to antibiotics in combination with a sublethal concentration of ampicillin or erythromycin. The activity was assayed by using a modification of the classical agar-diffusion method against 3 resistant, pathogenic bacteria; Escherichia coli (ATCC BAA196), Staphylococcus aureus (ATCC BAA42), and Streptococcus pyogenes (ATCC BAA946). From the 60 ethanolic extracts, 12 (20%) of them in combination with ampicillin were able to reverse the resistance of Staphylococcus aureus and 8 (13%) with erythromycin yielded the same reversal with Streptococcus pyogenes. An extract from Sargassum sinicola was the only one that reversed the resistance to antibiotics against both Staphylococcus aureus and Streptococcus pyogenes. Our finding suggests that some algae may be source of compounds with the potential to reverse the antibiotic resistance of some bacteria. In addition, of the assayed extracts, 35 (57%) showed inhibitory activity against Staphylococcus aureus, 48 (78%) were active against Streptococcus pyogenes, but none was active against Escherichia coli. The most active extracts were from Laurencia spp., Gelidium robustus, Chnoospora implexa, Padina crispata, Gracilaria subsecundata, and Dictyopteris undulata

Seasonal variation of agar from Gracilaria vermiculophylla, effect of alkali treatment time, and stability of its Colagar

Gracilaria vermiculophylla, from Baja California Sur, Mexico, was studied in order to determine the seasonal variation of yield and quality of native and alkaline agar during 2007–2008. The highest alkaline agar yield was obtained in summer (17%) and the highest gel strength in spring (1,132 gcm−2). The highest melting temperature was 98°C (winter). The highest gelling temperature was 68°C (summer). The values obtained are within the range of the most important Gracilaria species harvested worldwide. During the agar extraction step, the best results were obtained after 30 min of alkali treatment with sodium hydroxide (7%), after which the quality decreased significantly. We produced Colagar from G. vermiculophylla which consists of the seaweeds treated with sodium hydroxide and dried. The yield and quality of the agar obtained from the Colagar shows stability in both yield and quality during 1 year of storage, suggesting that alkali treatment is a good method of avoiding agar hydrolysis during storage

Anticoagulant screening of marine algae from Mexico, and partial characterization of the active sulfated polysaccharide from Eisenia arborea

The in vitro anticoagulant activity of 41 water extracts of various seaweeds from Baja California Sur, Mexico was evaluated. In this study, nine extracts exhibited anticoagulant activity in the prothrombin time assay, and 29 extracts were active in the activated partial thromboplastin time assay. The water extract obtained at 25°C from the brown seaweed Eisenia arborea was the most active in both assays, increasing the normal blood clotting-time over 300 s at 100 mg mL-1. The fractionation of this extract by anion exchange chromatography yielded 3 fractions. Fraction 2 eluted with 1.0 M sodium chloride increased the clotting-time over 300 s in the activated partial thromboplastin time assay at 5 µg mL-1, being more active than sodium heparin. Chemical and spectroscopic analysis of fraction 2 showed to be a heterofucan sulfated composed by 56.2% ±0.1 of total sugars, and 45% of sulfates. The neutral sugar constituents of the active heterofucan was determined to be 47.6% flucose, 35.5% xylose and 16.9% thamnose, with substitution of sulfate groups at C-4 (axial), and minor substitutions at C-2 and-or C-3

Monthly variation in the chemical composition of Eisenia arborea J.E. Areschoug

The brown alga Eisenia arborea is the second most abundant brown alga along the western coast of the Baja California Peninsula of Mexico. Samples of E. arborea were collected in Bahía Asunción, BCS, over 10 months. Chemical composition was analyzed from dried alga (%, dw): moisture (10.34%), protein (9.44%), ash (24.77%), lipids (0.60%), fiber (5.22%), and carbohydrates (49%). Gross energy was 9.8 kJ g−1. Seven minerals were analyzed and the four most abundant were K, Na, Mg, and Ca, ranging from 907 to 7,946 mg.100 g−1. The concentrations of six vitamin levels were also determined: A, C, E, D3, B2, and B1. Seventeen amino acids were analyzed and the most abundant were glutamic acid, aspartic acid, and leucine. Total fatty acids ranged from 21 to 65 mg.100 g−1 (dw). Individua concentration were also determined for arachidonic acid, alpha linolenic acid, linoleic acid, eicosapentaenoic acid, and docosahexaenic acid. Sponins, cyanogenic glycosides, and alkaloids, were not detected. Our results suggest that E. arborea isa good candidate to be tested as supplement food animal, including human. It contains essential amino acid, is low in lipids and fiber, and could be a source of vitamins and minerals