Revista de Ciencias

Composición y distribución de los ordenes Ephemeroptera, Plecoptera y Trichoptera (Insecta) en rios de la Sierra Nevada de Santa Marta, Colombia

Cuatro ríos localizados en diferentes f ancos de la Sierra Nevada de Santa Marta (SNSM) fueron analizados para conocer la composición y distribución de los estados inmaduros de los órdenes Ephemeroptera, Plecoptera y Trichoptera (EPT). Los ríos Gaira, Tucurinca, Guatapuríy Rancherías, se evaluaron entre junio de 2009 y noviembre de 2010, con énfasis en su parte media y las relaciones entre la entomofauna y parámetros bióticos y abióticos. Los organismos se recolectaron con red Surber, red triangular y colecta manual. Se encontraron 3859 individuos agrupados en 16 familias y 32 géneros. Trichoptera presentó la mayor riqueza de géneros (68,5%) y Ephemeroptera fue el más abundante (48,2 %). Smicridea (Trichoptera) (18,6%), Tricorythodes (Ephemeroptera) (15,8%) y Anacroneuria (Plecoptera) (15,1%) registraron el mayor número de individuos. Los microhábitats grava y hojarasca evidenciaron las mayores abundancias de los EPT (35,8% y 35,3% respectivamente). El río Guatapuríregistró la mayor riqueza de géneros y de diversidad (S= 24; H'=2,39), mientras el río Gaira, mostró el menor nivel (S=15; H'=1,84). Metrichia, Mortoniella y Protoptila (Trichoptera) son nuevos registros para la región de la SNSM y se amplía la distribución de Americabaetis, Mayobaetis, Nanomis y Terpides (Ephemeroptera) para los ríos Guatapurí, Rancherias y Tucurinca y de Leucotrichia y Zumatrichia (Trichoptera) para el río Tucurinca

Four rivers located on different f anks of the Sierra Nevada de Santa Marta (SNSM) were studied to evaluate the composition and distribution of the immature stages of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT). The rivers Gaira, Tucurinca, Guatapurí, and Rancherías were analyzed between June 2009 and November 2010 with emphasis on their mid-altitude segments, and the relationships between the entomofauna and biotic and abiotic parameters. Immature specimens were captured using Surber and triangular nets, along with manual collections. A total of 3,859 immature individuals were collected, corresponding to 16 families and 32 genera. Trichoptera was the order with the largest number of genera (68.5%), while Ephemeroptera was the most abundant order (48.2%). Smicridea (Trichoptera) (18.6%), Tricorythodes (Ephemeroptera) (15.8%), and Anacroneuria (Plecoptera) (15.1%) were the genera with the leading number of individuals. The microhabitats of gravel and leaves reported the highest abundance of the EPT (35.8% and 35.3%, respectively). The Guatapuríriver reported the highest level of diversity and presence of genera (S = 24; H '= 2.39), while the Gaira river reported the lowest level (S = 15, H' = 1.84). New f ndings of Metrichia, Mortoniella, and Protoptila (Trichoptera) were reported for the SNSM region. In addition, new f ndings of Americabaetis, Mayobaetis, Nanomis, and Terpides (Ephemeroptera) indicate an increase in the distribution of these genera to the Guatapurí, Rancherias, and Tucurinca rivers. Similarly, an increase in the distribution of Zumatrichia and Leucotrichia (Trichoptera) was reported for these genera with new f ndings in the Tucurinca River

Alternanthera repens **and Bidens odorata, Resilience Medicinal Plants in Mexico City**

In Mexico, the use of medicinal plants to treat health disorders has been practiced since pre-Columbian times. Unfortunately, this knowledge has been lost over time, mainly in highly urbanized areas. We conduct an ethnobotanical survey about Alternanthera repens, Kuntze (Amaranthaceae) and Bidens odorata Cav. (Asteraceae) in Mexico City. A total of 500 people were interviewed, 250 of them were questioned about B. odorata and 250 in relation to A. repens, the questions included: common names, medicinal uses, part of the plant used, mode of preparation, route of administration and duration of treatment. This study revealed that both plant species are currently used in top diseases, in the study area, mostly to treat gastrointestinal disorders, specif cally diarrhea; A. repens is also recommended to treat fever and renal diseases, whereas B. odorata is used for treating diabetes, renal disorders and less frequently for fever and as forage. The results allow us to ensure that these plants are used today and are potentially important to continue with the determination of their pharmacological effects and other aspects

Use of mulching for the restauration of dry forests in Valle of Cauca

El bosque seco tropical es uno de los ecosistemas más amenazados por actividades humanas. Pese a eso, los esfuerzos para su restauración son insuf cientes. Como en otros bosques tropicales, las gramíneas exóticas constituyen una barrera importante para su regeneración natural. El acolchado (mulch) es una técnica utilizada en el control de plantas arvenses para su evitar la competencia con los árboles nativos durante el proceso de restauración. Se estudió el efecto de dos acolchados (vegetal y de cartón) sobre el crecimiento y supervivencia de cuatro especies de plantas nativas (Pithecellobium dulce, Achatocarpus nigricans, Cestrum cf. nocturnum y Croton gossypiifolius). También se estudió el efecto del acolchado sobre las arvenses y el suelo por seis meses. Se encontró mayor crecimiento en el diámetro bajo el tratamiento de acolchado vegetal. Este tratamiento también permitió mayor retención de humedad en el suelo en el periodo de menor precipitación. En ambos acolchados hubo un menor crecimiento de arvenses y se observó la colonización de commelináceas sobre las áreas tratadas. Se concluye que el uso de acolchados es viable para el control de gramíneas exóticas en áreas en restauración. La reducción en la variación en la humedad del suelo puede favorecer el crecimiento de las plantas nativas a largo plazo

Dry tropical forest is one of the most severely threatened ecosystems. Despite that, efforts for its restauration are insuf cient. As it happens with other tropical forests, exotic grasses constitute a common barrier for natural regeneration. Mulching is a technique used to control weeds to avoid competition with native trees during the restauration process. The effect of two types of mulching (straw and cardboard) on growth and survival of four species of native plants (Pithecellobium dulce, Achatocarpus nigricans, Cestrum cf. nocturnum and Croton gossypiifolius) was studied. Additionally, the effect of mulching on weeds and on soil was also studied for six months. It was found that diameter growth was higher when straw mulching was used for treatment. This treatment also fostered greater retention of humidity on the soil during periods of less rain precipitation for both mulching treatments. There was a lower growth of weeds recorded as well as the appearance of commelinaceas plants. It was concluded that mulching is a viable option for the control of exotic grasses on the restauration areas. The reduction in the variation of soil moisture could promote growth of native plants in a long run

Determinación de la viabilidad de semillas de orquídeas utilizando la prueba de Tetrazolio e Índigo Carmín

Algunas especies de orquídeas se encuentran en peligro de extinción a nivel mundial, debido a la intervención antrópica. Por consiguiente, se hace necesario analizar la capacidad germinativa (viabilidad) de las semillas de orquídeas como paso fundamental para la conservación de orquídeas. En este trabajo se determinó la viabilidad de las semillas de las especies de orquídeas Elleanthus arauntiacum, Epidendrum sp, Maxillaria sp, Odontoglossum lindenii, Prosthechea sp, Telipogon dubios, Stelis sp, Elleanthus sp, Epidendrum elongatum y Cyrtochilum sp, utilizando la prueba de Tetrazolio e Índigo Carmín. Se realizaron diferentes salidas de campo en la vereda El Escorial en Norte de Santander para la colección de las cápsulas maduras de las diferentes especies de orquídeas. Posteriormente, se evaluó la viabilidad de las semillas con la prueba de Tetrazolio e Índigo Carmín, seguidamente se evaluaron los datos arrojados de las dos pruebas trabajadas. El coef ciente de correlación entre la prueba de Tetrazolio e Índigo Carmín fue de 0,419, indicando una relación débil en las dos pruebas con diferencias estadísticamente signif cativas de P:0.05. Se encontró que la prueba de Tetrazolio fue la más ef ciente para determinar la viabilidad de las semillas de orquídeas objeto de estudio

Orchid species are endangered worldwide due to human intervention. Therefore, it is necessary to analyze the germination capacity (viability) of orchids' seeds as essencial step for its conservation. This research determined the viability of the seeds species of orchids Elleanthus arauntiacum, Epidendrum sp, Maxillaria sp, Odontoglossum lindenii, Prosthechea sp, Telipogon dubios, Stelis sp, Elleanthus sp, Epidendrum elongatum y Cyrtochilum sp, using the Tetrazolium and Indigo carmin tests. Several f eld trips to the province of El Escorial in Norte de Santander, Colombia were done for collection of mature capsules of the different species of orchids. Then, was the seeds' viability by using the tetrazolium and Indigo Carmine tests. Subsequently, the data obtained from the two tests was evaluated. The correlation coeff cient between the Tetrazolium and Indigo Carmine tests was 0.419, indicating a weak relationship between the two trials with statistically signif cant differences P:0.05. It was found that the tetrazolium test was the most eff cient to determine the viability of orchid seeds being studied

**Caracterización morfológica y molecular de Phytophthora en ají(Capsicum frutescens var. Tabasco), Valle del Cauca**

El objetivo de este trabajo fue la caracterización de posibles especies diferentes de Phytophthora en un terreno que apenas comenzaría a ser usado para la producción de ajítabasco (Capsicum frutescens Var. Tabasco) de calidad de exportación en una zona productora del Valle del Cauca. Phytophthora es un Oomiceto f topatógeno que ataca gran variedad de plantas, desde hortalizas hasta árboles maderables y tiene varias especies que se han encontrado en estudios del tizón tardío, moho polvoso y putrefacción de la raíz del ají. El ajítabasco es una de las variedades de mayor demanda en el mercado, y por ello es preciso profundizar en los estudios referentes a la prevención y control de las enfermedades que atacan este cultivo. Para esta investigación se hizo una colecta aleatoria de suelo del cultivo de ajítabasco dentro de un perímetro de 20cm alrededor de la plántula y dentro del canal entre camas de siembra. Se aislaron dos morfotipos de Phytophthora a los que se extrajo ADN con el kit PowerSoil® DNA Isolation Kit (laboratorios MO-BIO Inc.), y se corrió una PCR, demostrando diferencia en el tamaño de las bandas. Al comparar las secuencias de las regiones ITS1 e ITS4, se encontró una similitud del 99% entre aislamiento PI y Phytophthora cinnamomi; el caso del aislamiento P2 tuvo una estrecha relación con el grupo perteneciente a Phytophtora infestans, P. nicotianae y P.tentaculata

The purpose of this work was the characterization of possible different species of Phytophtho in a f eld that ust begun to be used for the production of Tabasco pepper (Capsicum frutescens Var. Tabasco) of exporting quality, in a growing area of Valle del Cauca. Phytophthora is a phytopathogen oomycete which attacks wide variety of plants, from vegetables to timber trees, and has several species that have been found in studies of pepper's late blight, powdery mildew and root rot. The Tabasco pepper is one of the most demanded varieties in the market, and for this reason, it is necessary to deepen the studies on the prevention and control of diseases that attack the crop. For this investigation, a random collection of soil was made from the Tabasco pepper crop, within a perimeter of 20cm around the seedling and inside the channel between planting beds. Two Phytophthora morphotypes were isolated to which DNA was extracted with the PowerSoil® DNA Isolation Kit (MO-BIO Laboratories Inc.), and a PCR was run, showing different band sizes. By comparing the sequences of the ITSI and ITS4 regions, a similarity of 99% was found between isolation PI and Phytophthora cinnamomi; the isolation P2 (80%) had a close relationship with the group belonging to Phytophthora infestans, P. nicotianae and P.tentaculata

Photonic Filters Using Optical Retarders Based on Birefringent Optical Media

Photonic f lters can be used for f ltering the spectrum of wide-band optical sources such as light emitting diodes (LED) or multimode laser diodes (MMLD). In this work the use of birefringent optical media such as polarization maintaining f ber (PMF) or birefringent optical waveguides on Lithium Niobate (LiNb03) crystal, perform as optical f lters. The birefringent optical media, used as optical retarders, modify the optical spectrum by "channelizing" them. These devices act as photonic f lters, thus modifying an optical spectrum. As reported in this paper, integrated optics photonic f lters are easily implemented by birefringent optical waveguides on LiNbO3 electrooptic crystals. The practical f ltering of LED and be used for MMLD spectra is demonstrated in this work. The photonic f lters can implementing microwave f lters or optoelectronic multiplexing for radio or radio over f ber schemes

Equations of Lax type with several brackets

In the present paper we introduce a new hierarchy, each equation of which is defined by several brackets of two pseudodifferential operators. We deal with some algebraic properties of these equations. In particular, we show that, as in the classic case, they are related to the presence of an infinite sequence of first integrals. A new version of the Zakharov-Shabat type equations is proved. Formal solutions of this hierarchy are constructed using a "several brackets bilinear identity"

Comparison of DPPH Free Radical Scavenging, Ferric Reducing Antioxidant Power (FRAP), and Total Phenolic Content of Two Meriania Species (Melastomataceae)

Searching for new antioxidants used in pharmaceuticals, cosmetics or agrochemicals have increased today. Many phenolic compounds have been reported as promising for this goal. Melastomataceae is rich in these compounds. Consequently, in this research the antioxidant power for Meriania nobilis and M. hernandoi ( Melastomataceae) was compared. Both species were extracted in acetone 70%. The latest was liquid-liquid partitioned in ethyl acetate (Mn or Mh 2.1), n-butanol (Mn or Mh 2.2) and aqueous fractions (Mn or Mh 2.3). Antioxidant activity was measured by DPPH free radical scavenging method (FRS50, mg.L-1), ferric reducing antioxidant power assay (FRAP, mg FeS04.7H20 (100 g)-1ES) and total phenolic content (TPC, mg AG g-1ES) by Folin-Ciocalteu. The present study revealed that Mh 2.1 and Mh 2.2 from M. hernandoi have a strong antioxidant power FRS50 = 5.71±0.085, FRAP = 53±1.5 and TPC = 224±7.1 and FRS50 = 4.22±0.001, FRAP = 65 mg±1.5, TPC = 240 ±8.6 respectively, as compared with positive control, quercetin DPPH FRS50 = 4.20±0.410, FRAP = 61±1.3. M. nobilis exhibited poor antioxidant power FRS50 = 286±1.5, FRAP = 2.01±0.079 and TPC = 26±1.5. This paper showed M. hernandoi as good source of antioxidant compounds with potential usage as cosmetic, pharmaceutical or agrochemical ingredients