Experiencias pedagógicas significativas en matemática mediadas por recursos tecnológicos

Este trabajo describe experiencias pedagógicas innovadoras implementadas en matemática, en cursos de ingeniería. Dos experiencias fueron seleccionadas, una en el ámbito del álgebra y otra en matemática discreta. Cada una tiene características propias y actividades diferenciadas en cuanto al tipo de recursos tecnológicos utilizados y a la metodología de trabajo definida, pero ambas comparten aportes realizados a la formación experimental y a la resolución de problemas en ingeniería. Por un lado, se describen intervenciones educativas que usan aplicaciones tecnológicas disponibles para explorar conceptos de modelado y simulación numérica; por otro lado se pone énfasis en el desarrollo de aplicaciones tecnológicas requeridas a medida para validar, verificar propiedades, clasificar o realizar cálculos tediosos. Finalmente las actitudes colaborativas entre pares, brindaron a los estudiantes mejores oportunidades de aprender matemática

An intergenerational transmission of sustainability?:ancestral habitus and food production in a traditional agro-ecosystem of the Upper Guinea Forest, West Africa

The need for sustainable alternatives to industrial farming has led to a revival of interest in traditional agro-ecosystems. Whilst it is well recognised that traditional agro-ecosystems are both social and physical–technical – few case studies have examined interactions between both these dimensions in a single system. For a system to be considered sustainable it needs to be shown to have retained key characteristics over several generations. Case studies therefore demand a location where intergenerational transmission of agro-ecological knowledge and practice is ongoing. This paper examines the intergenerational transmission of social and physical–technical dimensions of a traditional agro-ecosystem of the Loma people in NW Liberia. We engage an innovative interdisciplinary combination of methodologies in analyzing interactions between: (i) energy efficiencies (yield to labour) in 3 different Loma food production systems, using longitudinal quantitative surveys, and, (ii) the social institutions that mediate food production practice, using qualitative methods. Our energy efficiency calculations show that AfDE cultivation is more than twice as efficient at producing calories as either shifting cultivation or forest and river extractivism, yet GPS mapping demonstrates that AfDE cultivation is highly spatially restricted despite clear opportunities for expansion and optimisation. This raises an important question: why have the Loma not expanded AfDE cultivation? We propose that despite being fully aware of the opportunities AfDEs present, a Loma ‘ancestral habitus’ and substantive economic rationality restrict areal expansion and optimisation of AfDE cultivation, curtailing growth and structuring a social-ecological system in dynamic equilibrium. Our findings underline that sustainability is not simply a physio-technical issue; social and belief issues appear to be far more important in framing behaviour in traditional agro-ecosystems

Sobre la presencia de Erythrina ulei Harms (Fabaceae) en Colombia

Erythrina is a genus pantropical with near 112 species, 75 well-know in the Neotróphic, many of them are cultivated in arrangements agroforestrys or used as ornamental. In Colombia they have reported 13 species, two of them introduced. In a recent revision of Erythrina for Colombia, the presence of E. ulei is reported in Colombia of an only collection carried out by R.E. Schultes in 1942 in the Colombo-Ecuadorian frontier, leaving in doubt the presence of this species in Colombian territory. Erythrina ulei is distributed in the whole Amazonia. Here we enlarge their district to the department of the Caquetá, being observed in the riversides of the gulch The Yuca and the river Hacha, in the vicinity of the municipality of Florencia

El uso de la Ayahuasca en la Amazonia

The yagé is a hallucinogenic plant (Banisteriopsis caapi) widely distributed in Colombia, Perú, Ecuador, Venezuela, Brazil and Bolivia, of which gets ready a drink (Ayahuasca) consumed from immemorial times inside an indigenous ritual context. Their preparation it is usually made with the bark of B. caapi, but in occasions additive are used, as the oco-yaje leaves or chagropanga (Diplopterys cabrerana: Malpighiaceae) and chacruna (Psychotria viridis: Rubiaceae), with the purpose of changing the psicoactivity effects of the drug, increasing their power and the duration of the trance. Besides the medicinal use, associated to the shamanism, there are different ways of consumption of this plant, among them: the vegetalism in Peru and Colombia and its associated practice to the Catholicism, magic and spiritualism in Brazil like the Union do Vegetal (UDV), Santo Daime and the Barquinha. The use of yage is synonymous with quality of life and health for Amazonian indigenous cultures. The cultural transformation which face today the indigenous cultures favors the loss of these ancestral practices affecting the welfare of the aboriginal people of the region and the culture of yage disappears with the death of old wise persons

Forced migration and indigenous knowledge of displaced Emberá and Uitoto populations in Colombia:an ethnobotanical perspective

Relatively little attention has been given to documenting changes in the ethnobotanical knowl-edge of displaced indigenous groups in Colombia. Such information is highly valuable becauseit contributes to our understanding of the changes that occur during this process of displace-ment, cultural transformation and loss, and because it eventually could shed some light indesigning social, economic, and educational policies that would facilitate their incorporationinto mainstream culture, through ways that validate their indigenous identity, knowledge, andtraditions. Based on our on-going research, herein we summarize ethnobotanical informationof two indigenous groups currently residing in the city of Florencia (capital of the Departmentof Caquetá) in the Northwestern Amazon basin: the Emberá, originally from northwesternColombia, and Uitoto, originally from the Colombian Amazon. By focusing in the indigenousethnobotanical knowledge of these two displaced groups, we intend to show the revitalizationof ethnobotanical knowledge, resilience, and multiple resources in form of ancestral knowl-edge that are brought and transmitted by these groups as they struggle for survival, in manytimes hostile urban environments. We hope to draw more attention to and encourage similarstudies on other displaced indigenous populations in Colombia as well as in other areas of LatinAmeric

Plantas útiles en una comunidad indígena Murui-Muinane desplazada a la ciudad de Florencia (Caquetá Colombia)

Ethnobotanical studies on the displaced indigenous groups of Colombia are scarce. This research report provides a list of 54 plant species (50 genera in 32 families) used by a displaced group of Murui-Muinane (= Witoto, Uitoto, Huitoto) that lives in the city of Florencia, capital of the Department of Caqueta. Only six (11%) plant species are not native to the Americas. Arecaceae and Fabaceae were the families with the highest number of species: eight and six respectively. The three categories of use with the highest number of species were: food (27 spp.), medicinal (15) and handicrafts (15). These 54 plant species used by the Murui in Florencia correspond to 19% of the total number of plants recorded as used by a Murui community that lives in a forested reservation in the Department of Putumayo. Such difference in the number of useful plants is noteworthy given that Colombian indigenous cultures are rapidly transforming and their ethnobotanical knowledge might be lost forever

Seeds used in handicraft manufactured by an Embera-Katio indigenous population displaced by violence in Colombia

The sale of handicrafts embellished with seeds is an important source of income for a displaced indigenous Emberá-Katío group that lives in the city of Florencia (Departamento of Caquetá, Colombia). We provide a list of the 34 plant species (23 genera in 10 families) used in handicrafts, as well as information on where and how the are obtained. Seeds of native legumes (family Fabaceae) are the main material used. Most manufactured items have seeds of Ormosia nobilis (Fabaceae), Canna edulis (Cannaceae), and Sapindus saponaria (Sapindaceae). About half of the plant species used by the Emberá-Katío are perennial trees. Except for the seeds of Coix lacryma-jobi (Poaceae) and Ormosia sp., which are obtained from other local indigenous groups such as the Koreguajes and Uitotos, all seeds are collected from small patches of secondary forest near or within the city. Because most plants used are native and widely distributed in the Neotropical region, we suggest that, despite cultural transformation, at least some cultural knowledge about native plants is still maintained, and we speculate that other Emberá groups might use the same or similar plant species. We also provide the Spanish and Emberá names of the plants used in the handicrafts

Un problema motivador para un trabajo interdisciplinario en matemática y física

El trabajo interdisciplinario, cuando es posible, juega un papel importante en la enseñanza y aprendizaje de las ciencias en los tres niveles de la educación argentina. En la actualidad se ha revalorizado la planificación de las tareas de investigación y resolución de problemas (Gil,D.,et al., 1991), de modo que cuando se planifica una unidad didáctica se deben integrar los conocimientos científicos, didácticos y la experiencia práctica, y se deben tomar en cuenta la estructura cognitiva y las concepciones de los alumnos a quienes va dirigida. Esta propuesta es un trabajo interdisciplinario entre la Matemática y la Física, que surge teniendo en cuenta dichas tendencias. Además no debe olvidarse que en un principio la Física se mostraba indistinguible de la Matemática y que los mayores avances matemáticos surgieron a partir de problemas relacionados con la Física

How to identify food deserts in Amazonian cities?

Food deserts are areas without affordable access to healthy foods. This paper explores whether food deserts are present within urban areas of the Brazilian Amazon. The availability and price of a variety of food products was surveyed in a total of 304 shops, across 3 cities in 2015. Least-cost distances were calculated to estimate travel distance to access products, with map overlay used to help identify areas with poor access to a variety of healthy food - these were defined as food deserts

Plants of the Araceae for malaria and related diseases:a review

We survey species of the Araceae family traditionally used for malaria and its symptoms. The aim is to reveal the large number of antimalarial Araceae species in use worldwide and their largely unexplored potential as sources of antimalarial natural products. The SciFinder Scholar, Scielo, PubMed, ScienceDirect and Google books search engines were consulted. Forty-three records were found of 36 species and 23 genera of Araceae used for malaria and symptoms. The neotropical genera Philodendron Schott and Anthurium Schott were the best represented for use in the treatment of malaria, fevers, liver problems and headaches. Leaves and tubers were the parts most used and decoction was the most common preparation method. Extracts of Araceae species inhibit the in vitro growth of the human malaria parasite Plasmodium falciparum Welch and significant median inhibitory concentrations (IC50) for extracts of guaimbê-sulcado (Rhaphidophora decursiva (Roxb.) Schott), aninga (Montrichardia linifera (Arruda) Schott), Culcasia lancifolia N.E. Br. and forest anchomanes (Anchomanes difformis (Blume) Engl.) have been reported demonstrating the antimalarial potential and cytotoxicity of extracts and sub-fractions. In the only report on the antimalarial components of this family, the neolignan polysyphorin and the benzoperoxide rhaphidecurperoxin exhibited strong in vitro inhibition of the D6 and W2 strains of Plasmodium falciparum (IC50 = 368-540 ng/mL). No study on the in vivo antimalarial activity in animal models has been conducted on a species of Araceae. More bioguided chemical composition studies on the in vitro and also in vivo antimalarial activity of the Araceae are needed to further the knowledge of the antimalarial potential of this family