125 research outputs found
Reglas de combinación de los efectos de las tres componentes de terremotos y respuesta crítica
La precisión de las reglas de combinación del 30% y SRSS, y la orientación crítica de las componentes de terremotos se estudian en este trabajo. Se analizan modelos estructurales complejos que representan edificios de baja y mediana altura. Se realiza un análisis estadístico de la precisión de las reglas de combinación aplicadas a parámetros de respuesta individuales y múltiples. El efecto de la correlación entre las componentes de los terremotos en dicha precisión también se estudia. Finalmente, se realizan análisis con varios ángulos de incidencia de las componentes con la finalidad de encontrar la orientación crítica. Los resultados muestran que las reglas subestiman la carga axial en columnas, pero sobreestiman razonablemente los cortantes de entrepiso. Ambas reglas son más conservadoras cuando los modelos se excitan por las tres componentes. Los efectos individuales pueden estar altamente correlacionados, incluso para componentes principales no correlacionadas. Las reglas no siempre son precisas para valores pequeños de coeficientes de correlación, y valores altos de éstos no siempre están relacionados a una estimación imprecisa de la respuesta combinada. La precisión de las reglas de combinación depende del grado de correlación de las componentes, del parámetro de respuesta, de la localización del elemento considerado y del nivel de deformación estructural
Evaluating the utility of camera traps in field studies of predation
Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes (Micrurus) and their mimics, observational data from 109 artificial snake prey were collected from video-recording camera traps in three locations in the Americas (terra firme forest, Tiputini Biodiversity Station, Ecuador; premontane wet forest, Nahá Reserve, Mexico; longleaf pine forest, Southeastern Coastal Plain, North Carolina, USA). During 1,536 camera days, a total of 268 observations of 20 putative snake predator species were recorded in the vicinity of artificial prey. Predators were observed to detect artificial prey 52 times, but only 21 attacks were recorded. Mammals were the most commonly recorded group of predators near replicas (243) and were responsible for most detections (48) and attacks (20). There was no difference between avian or mammalian predators in their probability of detecting replicas nor in their probability of attacking replicas after detecting them. Bite and beak marks left on clay replicas registered a higher ratio of avian:mammalian attacks than videos registered. Approximately 61.5% of artificial prey monitored with cameras remained undetected by predators throughout the duration of the experiments. Observational data collected from videos could provide more robust inferences on the relative fitness of different prey phenotypes, predator behavior, and the relative contribution of different predator species to selection on prey. However, we estimate that the level of predator activity necessary for the benefit of additional information that videos provide to be worth their financial costs is achieved in fewer than 20% of published artificial prey studies. Although we suggest future predation studies employing artificial prey to consider using videography as a tool to inspire new, more focused inquiry, the investment in camera traps is unlikely to be worth the expense for most artificial prey studies until the cost:benefit ratio decreases
A new species of pitviper of the genus Bothrops (Serpentes: Viperidae: Crotalinae) from the Central Andes of South America
We describe a new species of montane pitviper of the genus Bothrops from the Cordillera Oriental of the Central Andes, distributed from southern Peru to central Bolivia. The new species can be distinguished from its congeners by the characteristic combination of a dorsal body color pattern consisting of triangular or subtriangular dark brown dorsal blotches, paired dark brown parallel occipital stripes, a conspicuous dark brown postocular stripe, the presence of canthorostrals in some specimens, prelacunal fused or partially fused with second supralabial, one scale usually separating internasals, rostral trapezoidal, two canthals oval to rounded, similar size or slightly larger than internasals, three or four medial intercanthals, eight to twelve intersupraoculars, intercanthals and intersupraoculars keeled and frequently slightly keeled, supraoculars oval, one to three suboculars, two to three postoculars, loreal subtriangular, two to six prefoveals, subfoveals absent, two or none postfoveals, one or two scales between suboculars and fourth supralabial, seven or eight supralabials, nine or eleven infralabials, 23-25 middorsal scales, 189-195 ventrals in females and 182-190 in males, 48-58 subcaudals in females and 54-63 in males, exceptionally undivided. The new species is apparently restricted to areas within Andean montane forests that are less humid and devoid of large trees.Fil: Timms, J.. Museo Nacional de Ciencias Naturales; EspañaFil: Chaparro Auza, Juan C.. Museo de Biodiversidad del Perú; PerúFil: Venegas, Pablo J.. Centro de Ornitología y Biodiversidad; PerúFil: Salazar Valenzuela, David. Universidad Tecnológica Indoamérica; EcuadorFil: Scrocchi Manfrini, Gustavo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Cuevas, Jairo. Universidad Complutense de Madrid; EspañaFil: Leynaud, Gerardo Cristhian. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; ArgentinaFil: Carrasco, Paola Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin
Caracterización morfológica y agronómica de dos genotipos de maíz (Zea mays L.) en la zona media de la parroquia Malchinguí
En Malchinguí se evaluó las características morfológicas y agronómicas de dos genotipos de maíz (Zea mays L.), estableciendo seis sitios experimentales en la zona media (2600 - 2900 msnm) de dicha Parroquia, bajo un diseño completo al azar (DCA). En el estudio se registraron nueve descriptores cuantitativos y siete cualitativos, obteniendo como resultado que los genotipos Pepa (P) y Amarillo (A) presentan diferencias en los siguientes descriptores: altura de planta (P: 106 cm; A: 194 cm), altura de mazorca (P: 59.93 cm; A: 77.82 cm), peso de mazorca (P: 84.08 g; A: 136.78 g), peso de grano (P: 73.41 g; A: 121.35 g), forma de mazorca (P: cónica; A: cilíndrica), color de raquis (P: rojo; A: blanco) y forma del grano (P: redondo; A: puntiagudo). Los demás descriptores mostraron similitud entre genotipos
Unlocking the potential of snake venom-based molecules against the malaria, Chagas disease, and leishmaniasis triad
Funding Information: This work received financial support from PT national funds ( FCT/MCTES , Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project CIRCNA/BRB/0281/2019 . Funding Information: This work received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project CIRCNA/BRB/0281/2019.The authors further thank FCT/MCTES for supporting Research Units LAQV-REQUIMTE (UIDB/50006/2020), GHTM (UID/Multi/04413/2020). Publisher Copyright: © 2023 The AuthorsMalaria, leishmaniasis and Chagas disease are vector-borne protozoal infections with a disproportionately high impact on the most fragile societies in the world, and despite malaria-focused research gained momentum in the past two decades, both trypanosomiases and leishmaniases remain neglected tropical diseases. Affordable effective drugs remain the mainstay of tackling this burden, but toxicicty, inneficiency against later stage disease, and drug resistance issues are serious shortcomings. One strategy to overcome these hurdles is to get new therapeutics or inspiration in nature. Indeed, snake venoms have been recognized as valuable sources of biomacromolecules, like peptides and proteins, with antiprotozoal activity. This review highlights major snake venom components active against at least one of the three aforementioned diseases, which include phospholipases A2, metalloproteases, L-amino acid oxidases, lectins, and oligopeptides. The relevance of this repertoire of biomacromolecules and the bottlenecks in their clinical translation are discussed considering approaches that should increase the success rate in this arduous task. Overall, this review underlines how venom-derived biomacromolecules could lead to pioneering antiprotozoal treatments and how the drug landscape for neglected diseases may be revolutionized by a closer look at venoms. Further investigations on poorly studied venoms is needed and could add new therapeutics to the pipeline.publishersversionepub_ahead_of_prin
The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Sloan Digital Sky Survey IV : mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z ~ 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z ~ 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing
three major spectroscopic programs. The Apache Point Observatory Galactic
Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky
Way stars at high resolution and high signal-to-noise ratio in the
near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA)
survey is obtaining spatially-resolved spectroscopy for thousands of nearby
galaxies (median redshift of z = 0.03). The extended Baryon Oscillation
Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas
distributions between redshifts z = 0.6 and 3.5 to constrain cosmology using
baryon acoustic oscillations, redshift space distortions, and the shape of the
power spectrum. Within eBOSS, we are conducting two major subprograms: the
SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray
AGN and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey
(TDSS), obtaining spectra of variable sources. All programs use the 2.5-meter
Sloan Foundation Telescope at Apache Point Observatory; observations there
began in Summer 2014. APOGEE-2 also operates a second near-infrared
spectrograph at the 2.5-meter du Pont Telescope at Las Campanas Observatory,
with observations beginning in early 2017. Observations at both facilities are
scheduled to continue through 2020. In keeping with previous SDSS policy,
SDSS-IV provides regularly scheduled public data releases; the first one, Data
Release 13, was made available in July 2016
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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