Vegetation density as deduced from ERTS-1 MSS response

Reflectance from vegetation increases with increasing vegetation density in the 0.75- to 1.35 micron wavelength interval. Therefore, ERTS-1 bands 6 (0.7 to 0.8 micron) and 7 (0.8 to 1.1 micron) contain information that should relate to the probable yield of crops and the animal carrying capacity of rangeland. The results of an experiment designed specifically to test the relations among leaf area index (LAI), plant population, plant cover and plant height, and the ERTS-1 MSS responses for 3 corn, 10 sorghum, and 10 cotton fields are given. Plant population was as useful as LAI for characterizing the sorghum and corn fields, and plant height was as good as LAI for characterizing cotton fields. These findings generally support the utility of ERTS-1 data for explaining variability in green biomass, harvestable forage and other indicators of productivity

Termites (Blattodea: Isoptera) of Canada, continental USA, and Mexico: an identification key to families and genera, checklist of species, and new records for Mexico

An illustrated identification key to the North American termite families and genera based mainly on the soldier caste is proposed. A checklist of termites (Insecta: Blattodea: Isoptera) of Canada, continental USA and Mexico is presented, listing 89 species (and two subspecies) grouped in 26 genera and four families. Five species are added to the Mexican termite fauna, these records are for the states of Campeche: Cryptotermes cavifrons; Quintana Roo: Cryptotermes cavifrons, Neotermes holmgreni, Neotermes phragmosus, Neotermes mona; Sonora: Incisitermes banksi; and Yucatan: Neotermes phragmosus. Other 32 new state records are made for the states of Aguascalientes, Baja California Sur, Campeche, Chiapas, Jalisco, Nuevo Leon, Oaxaca, Quintana Roo, Sonora, and Yucatan. The species Coptotermes crassus, Coptotermes havilandi, Incisitermes perparvus, Microcerotermes strunckii, Nasutitermes costalis, Incisitermes nigritus and Termes melindae are eliminated from the termite fauna of this region.Se propone una clave de identificación para las familias y géneros de termitas norteamericanas basadas principalmente en la casta soldado. Se presenta un listado de termitas (Insecta: Blattodea: Isoptera) de Canadá, EE. UU. continental, y México, enlistando 89 especies (y dos subespecies) agrupadas en 26 géneros y cuatro familias. Cinco especies son añadidas a la termitofauna mexicana, estos registros son para los estados de Campeche: Cryptotermes cavifrons; Quintana Roo: Cryptotermes cavifrons, Neotermes holmgreni, Neotermes phragmosus, Neotermes mona; Sonora: Incisitermes banksi; y Yucatán: Neotermes phragmosus. Se hacen otros 32 nuevos registros estatales para los estados de Aguascalientes, Baja California Sur, Campeche, Chiapas, Jalisco, Nuevo León, Oaxaca, Quintana Roo, Sonora, y Yucatán. Las especies Coptotermes crassus, Coptotermes havilandi, Incisitermes perparvus, Microcerotermes strunckii, Nasutitermes costalis, Incisitermes nigritus, y Termes melindae son eliminadas de la termitofauna de esta región

Characterization of reagent pencils for deposition of reagents onto paper-based microfluidic devices

Reagent pencils allow for solvent-free deposition of reagents onto paper-based microfluidic devices. The pencils are portable, easy to use, extend the shelf-life of reagents, and offer a platform for customizing diagnostic devices at the point of care. In this work, reagent pencils were characterized by measuring the wear resistance of pencil cores made from polyethylene glycols (PEGs) with different molecular weights and incorporating various concentrations of three different reagents using a standard pin abrasion test, as well as by measuring the efficiency of reagent delivery from the pencils to the test zones of paper-based microfluidic devices using absorption spectroscopy and digital image colorimetry. The molecular weight of the PEG, concentration of the reagent, and the molecular weight of the reagent were all found to have an inverse correlation with the wear of the pencil cores, but the amount of reagent delivered to the test zone of a device correlated most strongly with the concentration of the reagent in the pencil core. Up to 49% of the total reagent deposited on a device with a pencil was released into the test zone, compared to 58% for reagents deposited from a solution. The results suggest that reagent pencils can be prepared for a variety of reagents using PEGs with molecular weights in the range of 2000 to 6000 g/mol

Assisted protein folding at low temperature: evolutionaryadaptation of the Antarctic fish chaperonin CCT and its clientproteins

Eukaryotic ectotherms of the Southern Ocean face energetic challenges to protein folding assisted by the cytosolic chaperonin CCT. We hypothesize that CCT and its client proteins (CPs) have co-evolved molecular adaptations that facilitate CCT–CP interaction and the ATP-driven folding cycle at low temperature. To test this hypothesis, we compared the functional and structural properties of CCT–CP systems from testis tissues of an Antarctic fish, Gobionotothen gibberifrons (Lo¨nnberg) (habitat/body T=-1.9 to +2˚C), and of the cow (body T=37˚C). We examined the temperature dependence of the binding of denatured CPs (bactin, b-tubulin) by fish and bovine CCTs, both in homologous and heterologous combinations and at temperatures between 24˚C and 20˚C, in a buffer conducive to binding of the denatured CP to the open conformation of CCT. In homologous combination, the percentage of G. gibberifrons CCT bound to CP declined linearly with increasing temperature, whereas the converse was true for bovine CCT. Binding of CCT to heterologous CPs was low, irrespective of temperature. When reactions were supplemented with ATP, G. gibberifrons CCT catalyzed the folding and release of actin at 2˚C. The ATPase activity of apo-CCT from G. gibberifrons at 4˚C was, 2.5-fold greater than that of apo-bovine CCT, whereas equivalent activities were observed at 20˚C. Based on these results, we conclude that the catalytic folding cycle of CCT from Antarctic fishes is partially compensated at their habitat temperature, probably by means of enhanced CP-binding affinity and increased flexibility of the CCT subunits

Contenido de compuestos Fenólicos y actividad antioxidante del arazá (Eugenia stipitata Mc Vaugh) en diferentes estados de maduración.

El Arazá(Eugenia stipitataMc Vaugh), despierta gran interés en dif'erentes ámbitos por las cualidades organotépticas dcl fruto y por el índice de producción de la planta. Con el objetivo de evaluar el potencial antioxidante del Arazá cultivado en el Departamento Caquetá. se evaluó la actividad de los extractos acuosos de la pulpa de Arazá en 5 dif'erentes estados de maduración (.A1: Vcrde: 42: Verde madurol A3: Pintón; A4: Maduro y 45: Sobre maduro), empleando las metodologías dc DPPH yABTS. 1, se cuantificó el contenido total dc f'enoles usando el ensayo cle Folin-Ciocalteu acorde con el método desamollado por Velioglu. Los resultados indican que la mayor actividad antioxidante la prcsentan las fnrtas de arazá en estado de maduración 43. con valores TEAC-DPPH de 81,9 ¡rmol trolox/l00 g extracto seco y TEAC- ABTS de 241,8 ¡unol trolox/I00 g extracto seco. En este mismo estado de maduración se encontró el mayor contenido de l'enoles totales (1063,9 rng ácido ascó¡bico/I00 g de extracto seco), por lo tanto, principalmentc a cstos compucstos fenólicos, puede ser atribuida la actividad antioxidante

Scalable and privacy-respectful interactive discovery of place semantics from human mobility traces

Mobility diaries of a large number of people are needed for assessing transportation infrastructure and for spatial development planning. Acquisition of personal mobility diaries through population surveys is a costly and error-prone endeavour. We examine an alternative approach to obtaining similar information from episodic digital traces of people’s presence in various locations, which appear when people use their mobile devices for making phone calls, accessing the internet, or posting georeferenced contents (texts, photos, or videos) in social media. Having episodic traces of a person over a long time period, it is possible to detect significant (repeatedly visited) personal places and identify them as home, work, or place of social activities based on temporal patterns of a person’s presence in these places. Such analysis, however, can lead to compromising personal privacy. We have investigated the feasibility of deriving place meanings and reconstructing personal mobility diaries while preserving the privacy of individuals whose data are analysed. We have devised a visual analytics approach and a set of supporting tools making such privacy-preserving analysis possible. The approach was tested in two case studies with publicly available data: simulated tracks from the VAST Challenge 2014 and real traces built from georeferenced Twitter posts

Elaboración del silicio poroso tipo p y caracterización morfológica mediante microscopía de fuerza atómica

Se presenta un sistema para la elaboración del Silicio Poroso (SP) tipo p y su caracterización morfológica. El SP es elaborado mediante un ataque electroquímico de un cristal de silicio tipo p en una solución con acido fluorhídrico (HF) dentro de una celda electroquímica a la cual es aplicada una corriente constante mediante un electrodo de platino y otro de silicio con un contacto óhmico de plata. La caracterización del SP se obtuvo mediante la técnica de microscopia de fuerza atómica (AFM).Palabras clave: Semiconductor, Silicio poroso, ataque electroquímico, ácido fluorhídrico