37 research outputs found
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale
Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV
Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values
Pedagogía en valores cívicos para la democracia y la convivencia ciudadana en la escuela
Titulo en ingles: Pedagogy of civic values for the democracy and harmonic coexistence in the school.RESUMEN: Desde hace varias décadas el sistema educativo colombiano viene preocupándose por diseñar e introducir en los currículos, modelos de educación en valores que puedan contribuir a superar la crisis social que afecta el desarrollo de nuevos ciudadanos y parece agudizarse cada día. Esta investigación se desarrolló en el intento de buscar la construcción de una pedagogía de valores cívicos para la democracia y la convivencia ciudadana, pretendiendo apoyar la formación de un ciudadano acorde con el proyecto político educativo del país en el cual la democracia y la convivencia se constituyen en pilares fundamentales. Las estrategias empleadas, son fundamentalmente lúdicas a partir de expresiones literarias.Palabras Clave: Pedagogía, valores, convivencia, estrategias lúdicas, expresiones literarias.ABSTRACT: For several decades Colombian educational system has been concerned about designing and introducing in the curriculums, models to teach values that would contribute to overcoming the social crisis which seems to be worst every day, and is affecting the development of its new citizens. This research was carried out with the intention of finding ways to develop pedagogy for teaching civic values for democracy and harmonic coexistence to support the formation of young citizens in accordance with the political educational project of the country in which democracy and peaceful coexistence are fundamental pillars. The strategics used are fundamentally ludicis, beginning with literary expressions.Key words: Pedagogy, values, ludicis-strategies, literary expressions.Titulo en ingles: Pedagogy of civic values for the democracy and harmonic coexistence in the school.RESUMEN: Desde hace varias décadas el sistema educativo colombiano viene preocupándose por diseñar e introducir en los currículos, modelos de educación en valores que puedan contribuir a superar la crisis social que afecta el desarrollo de nuevos ciudadanos y parece agudizarse cada día. Esta investigación se desarrolló en el intento de buscar la construcción de una pedagogía de valores cívicos para la democracia y la convivencia ciudadana, pretendiendo apoyar la formación de un ciudadano acorde con el proyecto político educativo del país en el cual la democracia y la convivencia se constituyen en pilares fundamentales. Las estrategias empleadas, son fundamentalmente lúdicas a partir de expresiones literarias.Palabras Clave: Pedagogía, valores, convivencia, estrategias lúdicas, expresiones literarias.ABSTRACT: For several decades Colombian educational system has been concerned about designing and introducing in the curriculums, models to teach values that would contribute to overcoming the social crisis which seems to be worst every day, and is affecting the development of its new citizens. This research was carried out with the intention of finding ways to develop pedagogy for teaching civic values for democracy and harmonic coexistence to support the formation of young citizens in accordance with the political educational project of the country in which democracy and peaceful coexistence are fundamental pillars. The strategics used are fundamentally ludicis, beginning with literary expressions.Key words: Pedagogy, values, ludicis-strategies, literary expressions
Differential regulation of K+ channels in Arabidopsis epidermal and stelar root cells.
The patch clamp technique was applied to protoplasts isolated from the epidermis and pericycle of Arabidopsis roots and their plasma membrane currents investigated. In the whole cell configuration, all protoplasts from the epidermis exhibited depolarization-activated time-dependent outwardly rectifying (OR) currents whereas OR currents were present in only 50% of cells from the pericycle. The properties of the OR currents in the epidermis and pericycle were compared with respect to their selectivity, pharmacology and gating. The time-dependent activation kinetics, selectivity and sensitivity to extracellular tetraethyl ammonium of the OR current in each cell type were not significantly different. The reversal potential (Erev) of the OR currents indicated that they were primarily due to the movement of K+. However, the gating properties of the OR currents from the epidermis differed markedly from those exhibited in the pericycle. Although both cell types displayed OR currents with voltage-dependent gating modulated in a potassium-dependent fashion [i.e. the activation threshold (V0.5) was displaced to more positive voltages as extracellular K+ increased], the OR currents in the epidermis also displayed voltage-independent gating by extracellular K+ which dramatically regulated current density. In the present study, reducing extracellular K+ activity from 40 to 0.87 mm reduced the OR current density in epidermal cells by approximately 80%. The chord conductance of the OR current saturated as a function of extracellular K+ and could be fitted with a Michaelis–Menten function to yield a binding constant (Km) of 10.5 mm. The ability of other monovalent cations to substitute for K+-gating of the OR currents was also investigated and shown to exhibit a relative sequence of K+ ≥ Rb+ > Cs+ > Na+ ≥ Li+ (Eisenmann sequence IV) with respect to efficacy of gating. Furthermore, single channel recordings demonstrated that channel activity rather than the single channel conductance was modulated by extracellular K+. In contrast, OR current density in the pericycle was largely independent of extracellular K+. It is suggested that the contrasting gating properties of the K+ channels in the epidermis and pericycle reflect their different physiological roles, particularly with respect to their role in K+ (nutrient) transport from the soil solution to the shoot
Amplitude Stabilization of a THz Quantum-Cascade Laser using a Photonic Integrated Circuit
We demonstrate a method to stabilize the output power of a ∼3.3-THz quantum-cascade laser (QCL) using a photonic integrated circuit, consisting of a racetrack resonator (RTR) coupled to a QCL ridge waveguide. Amplitude stabilization was achieved for >300 seconds, without perturbation to the emission spectrum, by dynamically adjusting the electrical bias to the RTR, and hence the coupling between the QCL and RTR