252 research outputs found
Public transport accessibility model based on user experience of the urban context
Los desafíos de transporte urbano poseen importantes aspectos técnicos y geográficos, pero éstas son solo dimensiones parciales de la problemática urbana. Para diseñar sistemas de transporte que rompan con los modelos tradicionales se necesita darle un giro más humano a la movilidad, ya que todos los viajes comienzan y terminan con una distancia recorrida a pie. En tal sentido, la calidad del ambiente urbano que rodea las áreas de acceso al Transporte Público (TP) influye en la captación de pasajeros, determinando la experiencia que los usuarios tendrán en los segmentos de acceso, transición y egreso del modo elegido.
Este trabajo tiene como objeto elaborar una metodología para evaluar la accesibilidad a sistemas de TP. Se presentan los resultados preliminares del desarrollo de un modelo que intenta ampliar el alcance de las herramientas existentes de análisis, al brindar un marco metodológico a escala humana y desarrollar indicadores que describan cualidades experienciales. Se propone un modelo matemático de regresión ogística de seis variables predictivas, tres de ellas se refieren a aspectos materiales del viaje y tienen en cuenta la infraestructura urbana en diferentes escalas; otras tres se refieren a la experiencia de usuario que deriva de la interacción con el ambiente construido donde se produce el viaje.Mobility and transportation challenges in globalized cities have strong technical and locational facets, but these are only partial dimensions of the problematic. In order to design transportation systems that defy conventional models, a more humane shift towards mobility is needed, understanding that every trip starts and ends with a distance traveled by foot. Within this scope, the urban environment around public transport access areas influences catchment buffer distances, determined by the user experience during the access, transition and egress segments of the trip.
This research aims to elaborate a methodological framework to evaluate accessibility that widens the scope of existing analysis tools. The preliminary results of a human-scale accessibility model are presented, elaborating on descriptive indicators of experiential qualities. The Logistic Regression mathematical model used consists of six predictive variables. Three of them describe the material aspects of the trip in different urban scales and the other three account for the user experience that derives from his interaction with the surrounding environment.Fil: Barón, Gabriela N..
Consejo Nacional de Investigaciones Científicas y TécnicasFil: Allende, David G..Fil: Arena, Alejandro P.
Valence change of praseodymium in Pr0.5Ca0.5CoO3 investigated by x-ray absorption spectroscopy
X-ray absorption spectroscopy measurements in Pr0.5Ca0.5CoO3 were performed
at the Pr M4,5, Pr L3, and Ca L2,3 absorption edges as a function of
temperature below 300 K. Ca spectra show no changes down to 10 K while a
noticeable thermally dependent evolution takes place at the Pr edges across the
metal-insulator transition. Spectral changes are analyzed by different methods,
including multiple scattering simulations, which provide quantitative details
on an electron loss at Pr 4f orbitals. We conclude that in the insulating phase
a fraction [15(+5)%] of Pr3+ undergoes a further oxidation to adopt a
hybridized configuration composed of an admixture of atomic-like 4f1 states
(Pr4+) and f- symmetry states on the O 2p valence band (Pr3+L states)
indicative of a strong 4f- 2p interaction.Comment: 19 pages (.doc), 4 figures, Phys. Rev. B, in pres
Nueva España (México) (Reino). Perfiles topográficos. 1804
En la parte superior izquierda anotado en tinta de bugalla: "37", que corresponde a una signatura antiguaEscala gráfica vertical al margen derecho expresada en toesas, por conjetura con la de otro perfil de la misma colección (Sign. C-I a 78). Tabla vertical indicando diferentes alturas hasta 2.000 toesasCopia Digital. Real Academia de la Historia : 2010Relieve indicado por varios colores en pequeñas manchas punteadas. Toponimia de numerosas localidades entre el Cerro de Axusco y el del GiganteEn la parte inferior izquierda firmado por "G.A.D." Es copia del original de Alexander von HumboldtEl perfil de la "Representación Geognóstica del Declive Oriental del Reyno de Nueva España" está fechado en 1804 (Sign. C-I a 77.1-4). Publicado en: Atlas géographique et physique du royaume de la Nouvelle-Espagne (París, 1808-1811)Manuscrito iluminado a la aguada con punteado en verde, marrón y gris sobre fondo amarillo. Textos en tinta chin
Unilateral submandibular gland aplasia with ipsilateral sublingual gland hypertrophy presenting as a neck mass
The congenital absence off the major salivary glands is a very infrequent disorder, in which several glands are usually involved at the same time. Sometimes this disorder can be associated with other developmental anomalies. The unilateral aplasia of the submandibular gland is an extremely rare finding with only 14 cases reported in the literature. Clinically, this kind of patients may complain of dryness of the mouth, difficulties in chewing and swallowing, severe periodontal disease or multiple caries, but usually they follow an asymptomatic course. Salivary gland aplasia can be diagnosed with a large variety off imaging techniques, which include computer tomography (CT), magnetic resonance imaging (MRR), ultrasonography (UUS), sialography, or scintigraphy. In this paper we report a case off a patient referred to our department with a long term and progressive growing neck mass, who has an unilateral submandibular gland aplasia associated to an ipsilateral hypertrophy off the sublingual gland. © Medicina Oral S. L
Latin America ClimateSmart Villages AR4D sites: 2016 Inventory
Inventory of CSA practices
in Latin America’s ClimateSmart
Villages
A Review Characterizing 25 Ecosystem Challenges to Be Addressed by an Ecosystem Approach to Fisheries Management in Europe
The impacts of fisheries on ocean resources are no longer considered in isolation but should account for broader ecosystem effects. However, ongoing ecosystem-wide changes added to the inherent dynamics of marine ecosystems, create challenges for fisheries and fisheries management by affecting our ability to ensure future fishing opportunities and sustainable use of the seas. By reviewing a corpus of fisheries science literature, we contribute to informing managers and policymakers with considerations of the various threats to fisheries and the marine ecosystems that support them. We identify and describe 25 ecosystem challenges and 7 prominent families of management options to address them. We capture the challenges acting within three broad categories: (i) fishing impacts on the marine environments and future fishing opportunities, (ii) effects of environmental conditions on fish and fishing opportunities, and (iii) effects of context in terms of socioeconomics, fisheries management, and institutional set-up on fisheries. Our review shows that, while most EU fisheries are facing a similar array of challenges, some of them are specific to regions or individual fisheries. This is reflected in selected regional cases taking different perspectives to exemplify the challenges along with fishery-specific cases. These cases include the dramatic situation of the Baltic Sea cod, facing an array of cumulative pressures, the multiple and moving ecosystem interactions that rely on the North Sea forage fish facing climate change, the interaction of fishing and fish stocks in a fluctuating mixed fishery in the Celtic Sea, the bycatch of marine mammals and seabirds and habitat degradation in the Bay of Biscay, and finally the under capacity and lack of fundamental knowledge on some features of the EU Outermost Regions. In addition to these ecoregion specific findings, we discuss the outcomes of our review across the whole of European waters and we conclude by recognizing that there are knowledge gaps regarding the direction of causality, nonlinear responses, and confounding effects. All of the challenges we identify and characterize may guide further data collection and research coordination to improve our fundamental understanding of the system and to monitor real changes within it, both of which are required to inform an Ecosystem Approach to Fisheries Management (EAFM). An European EAFM could build upon an array of management measures currently tailored for fisheries management only, including promoting funding interdisciplinary research and ecosystem monitoring. Such integrative management should reduce uncertainties in environmental, social and economic trends, and lower the risk for disruptive events or ecosystem effects with far-reaching consequences, including a shift toward less productive marine ecosystems.En prens
Informe final: Priorizando inversiones en agricultura sostenible adaptada al clima en Guatemala
El siguiente informe abordará los resultados del primer y segundo taller de Priorización de Inversiones en Agricultura Sostenible Adaptada al Clima realizados los días 7 de Agosto de 2014 y 18 de Junio de 2015 respectivamente, en Ciudad de Guatemala, Guatemala. A través de las secciones se presentarán cada una de las actividades desarrolladas durante los eventos, y al mismo tiempo se hará un breve análisis de los principales resultados obtenidos junto con unas conclusiones finales.
La información aquí presentada, será el insumo necesario para completar el ciclo de priorización de prácticas ASAC dentro del Marco de Priorización e iniciar una etapa de construcción del entorno favorable para la adopción y escalamiento de portafolios de prácticas de Agricultura Sostenible Adaptada al Clima (ASAC) con la colaboración articulada entre el MAGA y los diferentes actores involucrados e identificados durante el proceso
Fuzzy approach for risk assessment of brominated flame retardants in aquatic ecosystems
Brominated flame retardants (BFR) are pollutants that represent a threat to both human health and environment due to their industrial use, their persistence and their ability to bioaccumulate and biomagnify in food chains, especially in the aquatic one. For the last ten years contamination levels for this type of compounds have been reported for European, North American and Asian human tissue, sediments and biota samples [1-3]. However, monitoring efforts into the assessment of BFRs contamination levels in Latin America are scarce.
In this study, a model for the evaluation of the environmental risk of BFRs in the aquatic ecosystems has been developed. It has been based on a technical application of the Fuzzy Theory [4]. In particular, three interconnected Fuzzy Inference Systems (FIS) have been created through the use of the Fuzzy Toolbox in Matlab. In order to improve and make the model scientifically robust, several international experts have been questioned about different information required to build the fuzzy system. Information from 38 questionnaires have been collected and statistically treated.Preprin
Measuring an Off-center Detonation through Infrared Line Profiles: The Peculiar Type Ia Supernova SN 2020qxp/ASASSN-20jq
We present and analyze a near-infrared (NIR) spectrum of the underluminous Type Ia supernova SN 2020qxp/ASASSN-20jq obtained with NIRES at the Keck Observatory, 191 days after B-band maximum. The spectrum is dominated by a number of broad emission features, including the [Fe ii] at 1.644 μm, which is highly asymmetric with a tilted top and a peak redshifted by ≈2000 km s-1. In comparison with 2D non-LTE synthetic spectra computed from 3D simulations of off-center delayed-detonation Chandrasekhar-mass (Mch) white dwarf (WD) models, we find good agreement between the observed lines and the synthetic profiles, and are able to unravel the structure of the progenitor's envelope. We find that the size and tilt of the [Fe ii] 1.644 μm profile (in velocity space) is an effective way to determine the location of an off-center delayed-detonation transition (DDT) and the viewing angle, and it requires a WD with a high central density of ∼4 × 109 g cm-3. We also tentatively identify a stable Ni feature around 1.9 μm characterized by a "pot-belly"profile that is slightly offset with respect to the kinematic center. In the case of SN 2020qxp/ASASSN-20jq, we estimate that the location of the DDT is ∼0.3MWD off center, which gives rise to an asymmetric distribution of the underlying ejecta. We also demonstrate that low-luminosity and high-density WD SN Ia progenitors exhibit a very strong overlap of Ca and 56Ni in physical space. This results in the formation of a prevalent [Ca ii] 0.73 μm emission feature that is sensitive to asymmetry effects. Our findings are discussed within the context of alternative scenarios, including off-center C/O detonations in He-triggered sub-MCh WDs and the direct collision of two WDs. Snapshot programs with Gemini/Keck/Very Large Telescope (VLT)/ELT-class instruments and our spectropolarimetry program are complementary to mid-IR spectra by the James Webb Space Telescope (JWST).P.H., A.F., B.H., D.C., and E.Y.H. acknowledge
support by the National Science Foundation (NSF) grant AST1715133. E.B. was supported in part by NASA grant
80NSSC20K0538. C.A. and B.J.S. are supported by NASA
grant 80NSSC19K1717 and NSF grants AST-1920392 and
AST-1911074. M.S. is supported by grants from the Villum
FONDEN (28021) and the Independent Research Fund Denmark (8021-00170B). M.A.T. acknowledges support from the
DOE CSGF through grant DE-SC0019323. L.G. acknowledges
financial support from the Spanish Ministry of Science,
Innovation and Universities (MICIU) under the 2019 Ramón
y Cajal program RYC2019-027683 and from the Spanish
MICIU project PID2020-115253GA-I00. C.R.B., E.Y.H., M.
M.P., N.B.S. and P.H. are supported by the NSF grant AST1613472
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