54 research outputs found
Spin-orbit and solvent effects in the luminescent [re6q8(ncs)6]4-, q=s, se, te clusters: molecular sensors and molecular devices
Indexación: ScieloRelativistic time-dependent density functional (TDDFT) calculations including spin orbit interactions via the zero order regular approximation (ZORA) and solvent effects using the COSMO model were carried out on the [Re6Q8(NCS)6]4- , (Q = S, Se, Te) clusters. These calculations indicate that the lowest energy allowed electronic transitions are characterized by being of LMCT type. The calculated absorption maximum tends to shift to longer wavelengths as the face-capping chalcogenide ligand becomes heavier. Thus our calculations predict that the [Re6Te8(NCS)6]4- cluster might be also luminescent. Due to the unusual properties exhibited by these and other isoelectronic and isostructural hexarhenium (III) chalcogenide clusters, hexamolybdenum halide clusters and hexatungsten halide clusters, we propose here the design of nanodevices, such as, molecular sensors and molecular nanocells for molecular electronics.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072010000100010&nrm=is
Nemo Tenetur Se Ipsum. El Derecho a guardar silencio
El principio nemo tenetur se ¡psum o lo que significa literalmentenadie puede representarse a sí mismo como culpable o como transgresortiene su origen más significativo en la Declaración de Derechos (Bill ofRights), la que agregó a la Constitución de los Estados Unidos la EnmiendaV, por la cual nadie puede ser compelido en un proceso criminal a dartestimonio contra uno mismo. Garantía que con posterioridad, en el casoMiranda con Arizona, alcanzó su más elaborada extensión1 al exigir quela persona que se halla bajo custodia policial al ser interrogada/tiene queser informada de: a) su derecho a guardar silencio; b) que lo que digapuede ser usado en su contra; entre otros derechos
El relanzamiento de integración sudamericana: PROSUR
El acoso escolar está considerado como una problemática social compleja que no solo concierne a las víctimas, victimarios u observadores, sino a la comunidad en general. Por ello, este estudio buscó determinar los En esta investigación se abordan los instrumentos políticos y sociales del Foro para el progreso e integración de América del sur (PROSUR) los cuales en el año 2019 encendieron nuevamente una luz para la integración suramericana integrándose 8 países de esta región, para promover, fortalecer e impulsar una unión entre esos estados. Esta integración es anhelada por muchos y criticada por varios. Por un lado, se analiza el nuevo intento de integración en la zona sur de América como herramienta para la erradicación de la pobreza, la igualdad de oportunidades e intercambio pluricultural entre toda la ciudadanía sudamericana. Por otro parte, se estudia y se describe la realidad de los instrumentos del Foro para el Progreso de América del Sur (PROSUR) el cual dará inicio a una nueva idea de integración regional y a la vista de todos aparenta ser la respuesta a tantos intentos pasados de unificación regional.This research addresses the political and social instruments of the Forum for the Progress and Integration of South America (PROSUR) which in 2019 again lit a light for South American integration, integrating 8 countries of this region, to promote, strengthen and promote a union between those states. This integration is desired by many and criticized by many. On the one hand, the new attempt at integration in the southern part of America is analyzed as a tool for the eradication of poverty, equal opportunities and multicultural exchange among all South American citizens. On the other hand, the reality of the instruments of the Forum for the Progress of South America (PROSUR) is studied and described, which will start a new idea of regional integration and, in view of all, it appears to be the answer to so many past attempts. of regional unification.Campus Lima Centr
THE IMPACT OF NEW INTERNATIONAL GUIDELINES MATERIALITY IN AUDITING ABOUT THE FINANCIAL INFORMATIONS OF SMEs
Durante la etapa de emisión de informe, los auditores deben evaluar cualitativa y cuantitativamente las distorsiones detectadas durante la auditoría y las posibles distorsiones derivadas de limitaciones relevantes en la extensión del trabajo. En este sentido, los factores cualitativos que contiene la Norma Internacional de Auditoría FC-450 (revisada y reeditada), plantean nuevos desafíos y compromisos, pues requieren entre otras circunstancias, una mayor carga de trabajo y la necesidad de utilizar el juicio profesional de forma más intensiva y reflexiva. En este artículo se resume una investigación que tuvo por objetivo pulsar la opinión del colectivo auditor mexicano, respecto a ciertas consecuencias que sobre dicho escenario podrían afectar a la calidad de la información financiera publicada por las PyMES auditadas. Mediante una encuesta y el uso de herramientas descriptivas, inferenciales y multivariantes, se obtuvo evidencia empírica que demuestra porqué el uso efectivo de los FC-450 se proyecta favorablemente sobre la calidad de la información contable y en qué medida contribuirán a disminuir la presencia de errores e irregularidades. Así, incrementa la fiabilidad, relevancia y adecuación de los estados financieros, permitiendo un mejor reflejo de la imagen fiel.During the issuance period of the accounting report, auditors should evaluate qualitatively and quantitatively the distortions identified during the audit and the possible distortions coming from the relevant limitations in the extension of the work. In this sense, the qualitative factors in the International Standard on Auditing FC-450 (revised and reprinted) implied in new challenges and commitments, once it requires, among other aspects, an increased workload and the need for professional judgment in a more intensive and reflective way. This paper summarizes an investigation whose objective was to evaluate the opinion of the Mexican auditors regarding certain consequences of such scenario, which could affect the quality of the financial information published by the small and medium enterprises (SMEs) audited. Through a survey research and the use of descriptive, inferential and multivariate statistics tools, empirical was drawn that shows why the effective use of the FC-450 is projected favorably on the quality of the accounting information and to what extent it contributes to reduce the presence of errors and irregularities. Therefore, it increases the reliability, relevance and adequacy of the financial statements, allowing a better reflection of the actual situation
Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters
Recent progress in studies of globular clusters has shown that they are not
simple stellar populations, being rather made of multiple generations. Evidence
stems both from photometry and spectroscopy. A new paradigm is then arising for
the formation of massive star clusters, which includes several episodes of star
formation. While this provides an explanation for several features of globular
clusters, including the second parameter problem, it also opens new
perspectives about the relation between globular clusters and the halo of our
Galaxy, and by extension of all populations with a high specific frequency of
globular clusters, such as, e.g., giant elliptical galaxies. We review progress
in this area, focusing on the most recent studies. Several points remain to be
properly understood, in particular those concerning the nature of the polluters
producing the abundance pattern in the clusters and the typical timescale, the
range of cluster masses where this phenomenon is active, and the relation
between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review
The Synoptic All-Sky Infrared (SASIR) Survey
We are proposing to conduct a multicolor, synoptic infrared (IR) imaging
survey of the Northern sky with a new, dedicated 6.5-meter telescope at San
Pedro M\'artir (SPM) Observatory. This initiative is being developed in
partnership with astronomy institutions in Mexico and the University of
California. The 4-year, dedicated survey, planned to begin in 2017, will reach
more than 100 times deeper than 2MASS. The Synoptic All-Sky Infrared (SASIR)
Survey will reveal the missing sample of faint red dwarf stars in the local
solar neighborhood, and the unprecedented sensitivity over such a wide field
will result in the discovery of thousands of z ~ 7 quasars (and reaching to z >
10), allowing detailed study (in concert with JWST and Giant Segmented Mirror
Telescopes) of the timing and the origin(s) of reionization. As a time-domain
survey, SASIR will reveal the dynamic infrared universe, opening new phase
space for discovery. Synoptic observations of over 10^6 supernovae and variable
stars will provide better distance measures than optical studies alone. SASIR
also provides significant synergy with other major Astro2010 facilities,
improving the overall scientific return of community investments. Compared to
optical-only measurements, IR colors vastly improve photometric redshifts to z
~ 4, enhancing dark energy and dark matter surveys based on weak lensing and
baryon oscillations. The wide field and ToO capabilities will enable a
connection of the gravitational wave and neutrino universe - with events
otherwise poorly localized on the sky - to transient electromagnetic phenomena.Comment: Revised version of submitted whitepaper to the "Optical and IR
Astronomy from the Ground" Program Prioritization Panel of the Astro2010
Decadal Survey; 23 page
The G9.62+0.19-F Hot Molecular Core - The infrared view on very young massive stars
(abridged) We present the results of an extensive infrared study of the
massive star-forming region G9.62+0.19. The data cover information from broad-
and narrow-band filters in the wavelength range from 1 to 19 micrometer and are
obtained with ESO's infrared cameras ISAAC and TIMMI2 and with SpectroCam-10
(Mt. Palomar). The high sensitivity and resolution provided by these facilities
revealed intriguing new details of this star-forming region and especially
about the embedded hot molecular core (HMC) - component F. We analyse the newly
found infrared sub-structure of four objects in this HMC region. While one of
these objects (F2) is probably a foreground field star, the nature of the
brightest object in the near-infrared there (F1) remains somewhat enigmatic.
Our new astrometry proves that this object is not coincident with the peak of
the molecular line emission of the HMC, but displaced by 1.7 arcsecs (nearly
10000 AU on a linear scale). We estimate this object to be an additional
embedded object with a dense dust shell. Very near the HMC location we find L'
band emission which strongly rises in flux towards longer wavelengths. We
presume that this emission (F4) arises from the envelope of the HMC which is
known to be associated with a molecular outflow roughly aligned along the line
of sight. Thus, the clearing effect of this outflow causes strong deviations
from spherical symmetry which might allow infrared emission from the HMC to
escape through the outflow cavities. This presents the first direct detection
of an HMC at a wavelength as short as 3.8 micron. At 11.7 and 18.75 micron, the
HMC counterpart F4 ultimately proves to be the most luminous IR source within
the G9.62+0.19-F region.Comment: 39 pages, 10 figures, accepted for publication in Astronomy &
Astrophysics. The paper contains several colour images. It is highly
advisable to go to the following website to get a high-resolution version of
this preprint:
http://www.tls-tautenburg.de/research/tls-research/papers/linz/G9.62.htm
Intensive field sampling increases the known extent of carbon-rich Amazonian peatland pole forests
Peatland pole forest is the most carbon-dense ecosystem in Amazonia, but its spatial distribution and species composition are poorly known. To address this knowledge gap, we quantified variation in the floristic composition, peat thickness, and the amount of carbon stored above and below ground of 102 forest plots and 53 transects in northern Peruvian Amazonia. This large dataset includes 571 ground reference points of peat thickness measurements across six ecosystem types. These field data were also used to generate a new land-cover classification based on multiple satellite products using a random forest classification. Peatland pole forests are floristically distinctive and dominated by thin-stemmed woody species such as Pachira nitida (Malvaceae), Platycarpum loretense (Rubiaceae), and Hevea guianensis (Euphorbiaceae). In contrast, palm swamps and open peatlands are dominated by Mauritia flexuosa (Arecaceae). Peatland pole forests have high peat thickness (274 ± 22 cm, mean ± 95% CI, n = 184) similar to open peatlands (282 ± 46 cm, n = 46), but greater than palm swamps (161 ± 17 cm, n = 220) and seasonally-flooded forest, terra firme, and white-sand forest where peat is rare or absent. As a result, peatland pole forest has exceptional carbon density (1,133 ± 93 Mg C ha−1). The new sites expand the known distribution of peatland pole forest by 61% within the Pastaza-Marañón Foreland basin, mainly alongside the Tigre river, to cover a total of 7540 km2 in northern Peruvian Amazonia. However, only 15% of the pole forest area is within a protected area, whilst an additional 26% lies within indigenous territories. The current low levels of protection and forest degradation but high threat from road paving projects makes the Tigre river basin a priority for conservation. The long-term conservation of peatland pole forests has the potential to make a large contribution towards international commitments to mitigate climate change
- …