Statistical tools for the improvement and optimization of electrochemical sensors

The response of electrochemical sensors for substance detection critically depends on the sensing potential, the value of which is often selected by the visual inspection of the sensor's response, as given by, for example, electrochemical methods like cyclic voltammetry (CV). Using experimental data from CV, we show how the selection of the sensing potential can affect the sensitivity and linear range of the measurements. Whenever the magnitude of the sensor's response is crucial, it can be better to optimize the sensor for its sensitivity; however, if the testing conditions involve a variable range of concentrations, with putative very small or high concentrations, a reliable response can be obtained if the sensor is optimized for the linear range.ITESO, A.C

Generación de ingresos y de trabajo a partir de datos etnobotánicos y de búsquedas en documentos de patentes

Se presenta un inventario del uso de pimientas de los géneros Capsicum y Piper en una comunidad quilombo remanente del estado de Amapá, Brasil, y se valoran las citas de estas especies en patentes y el potencial de generación de ingresos para la comunidad. Se realizaron entrevistas semiestructuradas en los huertos de 16 especialistas en pimientas con el método tour guiada, para conocer la diversidad de pimientas. Se aplicaron cuestionarios sobre el uso de pimientas y condiciones socioeconómicas en sus residencias a 80 habitantes de cuatro localidades. Se realizó un levantamiento de patentes en bancos de datos europeos y brasileños, y para obtener información sobre productos patentados con el tema ‘pimienta’ se utilizaron como criterio de búsqueda las palabras Piper, pimienta, pepper y Capsicum. Se destacaron siete taxones en dos familias, Piperaceae y Solanaceae, donde Capsicum frutescens L. obtuvo el mayor valor de uso (3,0), además de haber sido la especie más citas en los huertos. El país con más patentes depositadas (1607) fue China. Las pimientas usadas in situ por la comunidad poseen gran potencial de bioprospección según el levantamiento de patentes, aunque la venta a gran escala no sea el fuerte de la comunidad

Boraginaceae

A taxonomic study of Boraginaceae species found at the Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil, revealed that there are three genera and four species: Cordia curassavica (Jacq.) Roem. Schult., Cordia mucronata Fresen., Heliotropium polyphyllum Lehm. var. polyphyllum, and Tournefortia membranacea A. DC. The species are described, an identification key is given, together with geographic distribution and illustrations of each species.Apresenta-se o estudo taxonômico das espécies da família Boraginaceae ocorrentes no Parque Nacional da Restinga de Jurubatiba, Estado do Rio de Janeiro, Brasil, onde está representada por três gêneros e quatro táxons: Cordia curassavica (Jacq.) Roem. Schult., Cordia mucronata Fresen., Heliotropium polyphyllum Lehm. var. polyphyllum e Tournefortia membranacea A. DC. São dadas descrições e comentários dos táxons, distribuição geográfica, chave de identificação e ilustrações

Diversidade de plantas em quintais quilombolas, conhecimento local sobre uso e cultivo de pimentas na Amazônia Oriental, Brasil

Quintais florestais são áreas ao redor das casas, usadas de forma consorciada, combinando espécies arbóreas lenhosas com cultivos agrícolas e/ou animais. Sua principal função é produzir alimen­tos para o consumo familiar. O objetivo deste estudo foi verificar a diversidade e o conhecimento sobre o uso e cultivo de plantas em quintais florestais, com destaque às pimentas no estado do Amapá. A pesquisa foi realizada por meio de entrevistas semiestruturadas com 16 especialistas em pimentas em seus respectivos quintais, utilizando a técnica turnê-guiada em quatro localidades da Área de Proteção Ambiental do Rio Curiaú. O material coletado foi processado através do método usual em taxonomia e a diversidade dos quintais verificada pelo Índice de Shannon-Wiener. Foram registrados 5.141 indivíduos, de 64 famílias, 130 gêneros e 155 espécies; nove táxons de pimentas em 21 nomes populares per­tencentes às famílias Solanaceae e Piperaceae. Curiaú de Fora e Curiaú de Dentro apresentaram maior riqueza e Curiaú de Fora apresentou a maior diversidade de espécies. Os especialistas demonstraram conhecer e usar as espécies cultivadas como medicinal, alimentar, comercial, ritualístico, dentre outros, em especial Capsicum frutescens L. Os quintais apresentam-se como uma estratégia viável para a con­servação e manutenção da diversidade local

Demanda efectiva de vivienda de los trabajadores de la industria manufacturera de la ciudad de Cartagena

Tesis (Economista).--Universidad de Cartagena. Facultad de Ciencias Económicas. Programa de Economía, 1984.El presente estudio tiene por objeto plantear las formas de financiación que ofrecen las diferentes entidades financieras para facilitar la compra de vivienda y por ende la solución de un problema social

Improving self-supported nanowire arrays by response surface methodology

Nanostructured sensors are a promising high-sensitive alternative for H2O2 detection. However, nanostructuring increases the number of variables influencing the sensor's behavior, which raises the problem of choosing the best combination of variables and their levels to increase the sensor's sensitivity. The Response Surface Methodology (RSM) is a principled approach that has proved to be efficient in terms of the necessary steps to find the best subset of variable levels while considering possible interaction between factor levels. Here we applied the RSM to optimize a Nickel (Ni) sensor response to H2O2 fabricated using electrodeposition in nanoporous membranes of Polycarbonate (PCTE). As design variables, we used the length of the nanowire, the measuring potential, and H2O2 concentrations. Our self-supported nanowire array sensor achieved better results compared to planar and other nanostructured sensors.ITESO, A.C

Supramolecular Assemblies of Nucleoside Functionalized Carbon Nanotubes: Synthesis, Film Preparation, and Properties

Nucleoside-functionalized multi-walled carbon nanotubes (N-MWCNTs) were synthesized and characterized. A self-organization process using hydrogen bonding interactions was then used for the fabrication of self-assembled N-MWCNTs films free of stabilizing agents, polymers, or surfactants. Membranes were produced by using a simple water-dispersion-based vacuum-filtration method. Hydrogen-bond recognition was confirmed by analysis with IR spectroscopy and TEM images. Restoration of the electronic conduction properties in the N-MWCNTs membranes was performed by removing the organic portion by thermal treatment under an argon atmosphere to give d-N-MWCNTs. Electrical conductivity and thermal gravimetric analysis (TGA) measurements confirmed the efficiency of the annealing process. Finally, oxidative biodegradation of the films N-MWCNTs and d-N-MWCNTs was performed by using horseradish peroxidase (HRP) and low concentrations of H2O2. Our results confirm that functional groups play an important role in the biodegradation of CNT by HRP: N-MWCNTs films were completely biodegraded, whereas for d-N-MWCNTs films no degradation was observed, showing that the pristine CNT undergoes minimal enzyme-catalyzed oxidation This novel methodology offers a straightforward supramolecular strategy for the construction of conductive and biodegradable carbon nanotube films. Conductive and biodegradable films: A self-organization process using hydrogen-bond interactions (see scheme, MWCNT=multiwalled carbon nanotube) is used for the fabrication of conductive and biodegradable carbon nanotube films totally free of stabilizing agents, polymers, or surfactants

Caracterización y uso de “pimientas” en una comunidad quilombola de la Amazonía Oriental (Brasil)

Este estudio tuvo como objetivo evaluar la diversidad de las “pimientas” en la comunidad quilombola de cuatro localidades del Área de Protección Ambiental del Río Curiaú (Amapá, Brasil), a fin de lograr su caracterización taxonómica y sus usos tradicionales. Se realizaron entrevistas semi-estructuradas, con 16 especialistas locales, mediante los cuales en cada especimen citado se verificó su presencia y uso local. Se elaboró una clave diferencial de las especies, las que son detalladamente descriptas e ilustradas. Se registraron 22 etnoespecies y siete taxones: Piper tuberculatum Jacq. y P. marginatum Jacq. (Piperaceae); Capsicum annuum L. var. annuum and var. glabriusculum (Dunal) Heiser & Pickersgill, C. chinense Jacq., C. baccatum var. umbilicatum (Vell.) Hunz. et Barboza, and C. frutescens L. (Solanaceae). La “pimenta malagueta” (C. frutescens) fue la más reportada para el tratamiento de enfermedades, especialmente de la piel, además de sus indicaciones en practicas mágico-simbólicas. Los especialistas entrevistados demostraron un buen conocimiento sobre la utilización de estas especies como recursos medicinales, lo que constituiría una estrategia alternativa para su conservación.The aim of this study was to evaluate the diversity of “peppers” in the “quilombola” community within four regions of the Área de Protección Ambiental do Río Curiaú (Amapá, Brazil), in order to profile the taxonomy and traditional uses of the species. Semi-structured interviews were conducted, with 16 experts in their respective “peppers” homegardens, where both the presence of each specimen and its local use were verified. A key and detailed descriptions and illustrations of the species examined were developed. Seven taxa and 22 ethnospecies were recorded: Piper marginatum Jacq., P. tuberculatum Jacq. (Piperaceae); Capsicum annuum L. var. annuum and C. annuum var. glabriusculum (Dunal) Heiser & Pickersgill, C. chinense Jacq., C. baccatum var. umbilicatum (Vell.) Hunz. et Barboza, and C. frutescens L. (Solanaceae). Among ethnospecies, “pimenta malagueta” (C. frutescens)—in addition to its magical and symbolic attributes—was the species most commonly used for the treatment of diseases, especially skin disorders. Experts have demonstrated extensive knowledge of the use of these species as medicinal resources, and this may be an alternative strategy for the conservation of such species and/or their varieties.Fil: Araujo Pereira, Luciano. Jardin Botanico Do Rio de Janeiro; BrasilFil: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Bovini, Massimo Giuseppe. Jardin Botanico Do Rio de Janeiro; BrasilFil: Almeida, Mara Zélia de . Universidade Federal Da Bahia; BrasilFil: Guimarães, Elsie Franklin. Jardim Botanico Do Rio de Janeiro. Instituto de Pesquisas; Brasi

Artificially modified magnetic anisotropy in interconnected nanowire networks

Interconnected or crossed magnetic nanowire networks have been fabricated by electrodeposition into a polycarbonate template with crossed cylindrical nanopores oriented ±30° with respect to the surface normal. Tailor-made nanoporous polymer membranes have been designed by performing a double energetic heavy ion irradiation with fixed incidence angles. The Ni and Ni/NiFe nanowire networks have been characterized by magnetometry as well as ferromagnetic resonance and compared with parallel nanowire arrays of the same diameter and density. The most interesting feature of these nanostructured materials is a significant reduction of the magnetic anisotropy when the external field is applied perpendicular and parallel to the plane of the sample. This effect is attributed to the relative orientation of the nanowire axes with the applied field. Moreover, the microwave transmission spectra of these nanowire networks display an asymmetric linewidth broadening, which may be interesting for the development of low-pass filters. Nanoporous templates made of well-defined nanochannel network constitute an interesting approach to fabricate materials with controlled anisotropy and microwave absorption properties that can be easily modified by adjusting the relative orientation of the nanochannels, pore sizes and material composition along the length of the nanowire