La etnomatemática: los saberes matemáticos de los pueblos originarios

El presente trabajo es un avance del proyecto de investigación enfocado al conocimiento, reconocimiento, recuperación y educación de los saberes matemáticos de los rarámuri del estado de Chihuahua, los cuales son desdeñados en la educación indígena y publica, a pesar de su uso cotidiano en el trabajo, en sus rituales, en sus juegos. Se presenta un análisis y selección de estudios realizados por diversos autores en la etnomatemática a nivel internacional, nacional y regional, que incluyen saberes y conocimientos matemáticos de diversos grupos étnicos en las áreas de la numeración, la geometría y la astronomía. El fin es comunicar la experiencia de la búsqueda del dialogo de saberes matemáticos que sirvan para la formación de una nueva educación intercultural

La sexualidad durante el climaterio femenino en los Repartos, La Arrocera I y Marco Antonio Medina de la ciudad de León, marzo de 2004, febrero de 2005

Tesis (Lic. en Psicología)-Universidad Nacional Autónoma de Nicaragua, León.UNAN-Leó

Comparative study of the effects of black or white hail nets on the fruit quality of ‘Golden Delicious’ apples

Introduction. The use of hail nets to protect apples during development and maturation on the tree is very common in Mexico. This practice can cause changes in fruit quality and aroma composition. The effects of the hail net color on the quality and aroma volatile production of apple cultivated in Chihuahua, Mexico, were evaluated. Materials and methods. ‘Golden Delicious’ apple trees were covered with white or black hail nets. Apple samples were harvested weekly from August to early October, and analyzed for weight, axial and equatorial diameters, color (°Hue), firmness, total soluble solids (TSS), acidity, ethylene production (EC), and aroma volatile composition. The photosynthetically available radiation (PAR) was measured every ten days under each hail net and outside. Results and discussion. Apple quality was affected by hail net color. Black hail nets delayed maturation and quality development of apples by one week when compared with white hail nets. The PAR values were 18% lower under black nets than under white nets. Quality parameters at commercial harvest (162 days after full bloom) showed that white-net apples presented 7% lower firmness, 11.1% less acidity, 8.3% higher TSS and a more developed yellow color, when compared with black-net apples. In addition, white-net apples presented higher contents of the main aroma compounds (in μg L-1) 1-hexanol (8.09 vs. 4.38), 2-methyl-1-butanol (6.24 vs. 2.65), and 2-methyl-butyl acetate (0.47 vs. 0.16). At the same maturity stage (beginning of the climacteric rise), no difference was found between white- and black-net apples in TSS, acidity, firmness and aromatic compounds. Conclusion. Hail net functionality goes beyond protecting orchards from hail damage; hail net color affects the apple maturation rate, quality and aroma volatile production

Antimicrobial activity and thermal stability of rosemary essential oil:β−cyclodextrin capsules applied in tomato juice

Rosemary essential oil (RO) was encapsulated within β-cyclodextrin (β-CD) to offer thermal stability and preserve its antimicrobial activity. The identified RO volatiles were 1,8 cineole (52%), 3-carene (9.6%), and camphor (9.3%). The growth of Salmonella Typhimurium, Listeria monocytogenes, Candida tropicalis, and Saccharomyces pastorianus was inhibited by 10, 10, 4.5, and 1.5 mg of free RO per mL of media, respectively. However, RO exhibited its evaporation at 43 °C, losing 50% of its weight at 100 °C and decomposing at 130 °C. RO:β-CD, at a 16:84 wt ratio, showed the highest presence of RO volatiles (7.33 g of RO/100 g of capsules) and initiated its decomposition at 75 °C, accompanied by a 10% weight loss. These particles underwent decomposition at 290 °C. Infrared analysis of RO:β-CD showed molecular interactions between RO and β-CD. The minimal inhibitory concentrations of the encapsulated RO for S. Typhimurium, L. monocytogenes, C. tropicalis, and S. pastorianus were 14.66, 14.14, 2.05, and 3.07 mg/mL, respectively. RO capsules were stable during tomato juice pasteurization and maintained their antimicrobial activity. In conclusion, the encapsulation of RO by β-CD offered protection to the volatile constituents exposed to high temperatures and maintained its antimicrobial properties after the encapsulation process and pasteurization of tomato juice

Aceites esenciales de plantas nativas del Perú: Efecto del lugar de cultivo en las características fisicoquímicas y actividad antioxidante

Los aceites esenciales (AE) son usados como conservantes en la industria de alimentos, debido a sus características fisicoquímicas y actividad antioxidante. El objetivo de esta investigación fue determinar rendimiento (R), gravedad específica (GE), índice de refracción (IR), actividad antioxidante (AA) y composición química de AE de huacatay (Tagetes minuta), poleo (Minthostachys mollis), romero (Rosmarinus officinalis L.) y sachaculantro (Eryngium foetidum L.), plantas recolectadas de 52 distritos de la región Amazonas, Perú. Para cada AE se usó análisis de varianza de efectos fijos con tres repeticiones y análisis de clúster. La actividad antioxidante se determinó con el método del radical libre 2,2-difenil-1-picrilhidracilo (DPPH) y sus componentes más abundantes fueron identificados con cromatografía de gases acoplada a espectrometría de masas. Las diferencias en R, GE e IR fueron significativas entre distritos. La AA no mostró diferencia significativa entre los distritos, pero entre las plantas sí. Entre los componentes volátiles más abundantes se identificó 1–adamantanol (44,42%) en huacatay, β–felandreno (20,85%) en poleo, β–mirceno (34,59%) en romero y α–pineno (23,41%) en sachaculantro. Se concluye que el lugar geográfico afecta significativamente las propiedades fisicoquímicas de los AE

Growth Promotion of <i>Phaseolus vulgaris</i> and <i>Arabidopsis</i> <i>thaliana</i> Seedlings by Streptomycetes Volatile Compounds

Streptomyces are recognized as antipathogenic agents and plant-growth-promoting rhizobacteria. The objective of this study was to evaluate the capacities of four antifungal Streptomyces strains to: produce the substances that are involved in plant growth; solubilize phosphates; and fix nitrogen. The effects of the volatile organic compounds (VOCs) that are emitted by these strains on the growth promotion of Arabidopsis thaliana and Phaseolus vulgaris L. (var. Pinto Saltillo) seedlings were also tested. All of the Streptomyces strains produced indole-3-acetic acid (IAA) (10.0 mg/L to 77.5 mg/L) and solubilized phosphates, but they did not fix nitrogen. In vitro assays showed that the VOCs from Streptomyces increased the shoot fresh weights (89–399%) and the root fresh weights (94–300%) in A. thaliana seedlings; however, these effects were less evident in P. vulgaris. In situ experiments showed that all the Streptomyces strains increased the shoot fresh weight (11.64–43.92%), the shoot length (11.39–29.01%), the root fresh weight (80.11–140.90%), the root length (40.06–59.01%), the hypocotyl diameter (up to 6.35%), and the chlorophyll content (up to 10.0%) in P. vulgaris seedlings. 3-Methyl-2-butanol had the highest effect among the ten pure VOCs on the growth promotion of A. thaliana seedlings. The tested Streptomyces strains favored biomass accumulation in A. thaliana and P. vulgaris seedlings

Evaluation of Cooking Quality, Nutritional and Texture Characteristics of Pasta Added with Oat Bran and Apple Flour

This study reports the effect of the addition of oat bran and apple flour on the cooking quality, digestibility, antioxidant, nutritional and texture characteristics of a spaghetti-type pasta. Pasta samples were prepared by substituting 50% of durum wheat semolina with oat bran (OBP) or apple flour (AFP). AFP presented higher cooking loss and water absorption index than the control pasta prepared with 100% durum wheat semolina (WSP). The supplementation of pasta with oat bran increased the total dietary fiber content (16.43% w/w, dw), while apple flour decreased the protein content (11.16% w/w, dw). There was no significant difference in the resistant starch content among all pasta samples. The pasta samples made with 50/50 durum wheat semolina/oat bran and 50/50 durum wheat semolina/apple flour increased the antioxidant activity by &asymp;46% and &asymp;97%, respectively. The OBP and AFP samples had a similar texture to the control pasta. A 50% replacement of durum wheat semolina with oat bran in a pasta formulation decreased the caloric content and digestibility of its starch components. These attributes found in the oat bran pasta and apple flour pasta make them a healthy choice for the diet of people with specific nutritional needs

Elaboration and Characterization of Active Apple Starch Films Incorporated with Ellagic Acid

Apple starch films were obtained from apples harvested at 60, 70, 80 and 90 days after full bloom (DAFB). Mechanical properties and water vapor permeability (WVP) were evaluated. The apple starch films at 70 DAFB presented higher values in the variables of tensile strength (8.12 MPa), elastic modulus (3.10 MPa) and lower values of water vapor permeability (6.77 &#215; 10&#8722;11 g m&#8722;1 s&#8722;1 Pa&#8722;1) than apple starch films from apples harvested at 60, 80 and 90 DAFB. Therefore, these films were chosen to continue the study incorporating ellagic acid (EA). The EA was added at three concentrations [0.02% (FILM-EA0.02%), 0.05% (FILM-EA0.05%) and 0.1% (FILM-EA0.1%) w/w] and compared with the apple starch films without EA (FILM-Control). The films were characterized by their physicochemical, optical, morphological and mechanical properties. Their thermal stability and antioxidant capacity were also evaluated. The FILM-Control and FILM-EA0.02% showed a uniform surface, while FILM-EA0.05% and FILM-EA0.1% showed a rough surface and insoluble EA particles. Compared to FILM-Control, EA modified the values of tensile strength, elasticity modulus and elongation at break. The antioxidant capacity increased as EA concentration did. EA incorporation allowed obtaining films with higher antioxidant capacity, capable of blocking UV light with better mechanical properties than film without EA