CHEOPS Performance for Exomoons: The Detectability of Exomoons by Using Optimal Decision Algorithm

Many attempts have already been made to detect exomoons around transiting exoplanets, but the first confirmed discovery is still pending. The experiences that have been gathered so far allow us to better optimize future space telescopes for this challenge already during the development phase. In this paper we focus on the forthcoming CHaraterising ExOPlanet Satellite (CHEOPS), describing an optimized decision algorithm with step-by-step evaluation, and calculating the number of required transits for an exomoon detection for various planet moon configurations that can be observable by CHEOPS. We explore the most efficient way for such an observation to minimize the cost in observing time. Our study is based on PTV observations (photocentric transit timing variation) in simulated CHEOPS data, but the recipe does not depend on the actual detection method, and it can be substituted with, e.g., the photodynamical method for later applications. Using the current state-of-the-art level simulation of CHEOPS data we analyzed transit observation sets for different star planet moon configurations and performed a bootstrap analysis to determine their detection statistics. We have found that the detection limit is around an Earth-sized moon. In the case of favorable spatial configurations, systems with at least a large moon and a Neptune-sized planet, an 80% detection chance requires at least 5-6 transit observations on average. There is also a nonzero chance in the case of smaller moons, but the detection statistics deteriorate rapidly, while the necessary transit measurements increase quickly. After the CoRoT and Kepler spacecrafts, CHEOPS will be the next dedicated space telescope that will observe exoplanetary transits and characterize systems with known Doppler-planets. Although it has a smaller aperture than Kepler (the ratio of the mirror diameters is about 1/3) and is mounted with a CCD that is similar to Kepler's, it will observe brighter stars and operate with larger sampling rate; therefore, the detection limit for an exomoon can be the same as or better, which will make CHEOPS a competitive instruments in the quest for exomoons.

Preserving Family: Themes from a Qualitative Study of Kin Caregivers

This article presents themes from a qualitative study of 58 African American female kinship caregivers in San Francisco. Core concepts that emerged describe various paths along which children move into kin homes, and caregivers' mixed emotional reactions to becoming surrogate parents. Women also discussed multiple family roles they assumed after taking in children. Responses highlight three primary reasons for becoming caregivers that center on providing for and protecting these children—particularly from the perceived threat of the public foster care system—and ultimately preserving the family unit. Paradoxically, caregivers' reasons mirror the stated goals of the public foster care system, which they view as a threat to family stability. We discuss the problems of implementing practice and policy recommendations for permanency and family preservation and how to bridge the gap between the deeply held negative beliefs of African American caregivers towards the public system and begin to build trust.

Oxygen and carbon isotopic composition of shells from Radix sp. in lakes across the Tibetan Plateau

The Tibetan Plateau (TP), including its surrounding mountain ranges, represents the largest store of ice outside the polar regions. It hosts numerous lakes as well as the head waters of major Asian rivers, on which billions of people depend, and it is particularly sensitive to climate change. The moisture transport to the TP is controlled by the Indian and Pacific monsoon and the Westerlies. Understanding the evolution of the interaction of these circulation systems requires studies on climate archives in different spatial and temporal contexts. The objective of this study is to learn more about the interannual variability of precipitation patterns across the TP and how different hydrologic systems react to different climatic factors. Aragonite shells of the aquatic gastropod Radix, which is widely distributed in the region, may represent suitable archives for inferring hydrologic and climatic signals in particularly high resolution. Therefore, sclerochronological studies of d18O and d13C ratios in Radix shells from seven lakes were conducted, each representing a different hydrologic and climatic setting, on a transect from the Pamirs across the TP. The shell patterns exhibit an increasing influence of precipitation and a decreasing influence of evaporation on the isotope compositions from west to east. d18O values of shells from lakes on the eastern and central TP (Donggi Cona, Yamdrok Yumco, Tarab Co) mirror monsoon signals, indicated by more negative values and higher variabilities compared to the more western lakes (Karakul, Bangong/Nyak, Manasarovar). In Yadang Co, located on the central southern TP, the monsoon rains did not reach the lake in the sampling year, although it is located in a region which is usually affected by monsoon circulation. The d18O values are used to differentiate the annual hydrological cycle into ice cover period, melt water period, precipitation period and evaporation period. d13C compositions in the shells particularly depend on specific habitats, which vary in biological productivity and in carbon sources. d18O and d13C patterns show a positive covariance in shells originating from large closed basins. The results show that Radix shells mirror general climatic differences between the seven lake regions. These differences reflect both regional and local climate signals in sub-seasonal resolution, without noticeable dependence on the particular lake system.

Geochemical studies of surface sediment samples off North-West Africa

One hundred and twenty-eight surface-sediment samples collected off North-West Africa were studied geochemically to detect the expressions of different meridional climate regimes and zonal productivity gradients in the surface sediments. This geochemical multi-tracer approach, coupled with additional information on the bulk carbonate and TOC contents makes it possible to characterise the sedimentological regime in detail. Typical terrigenous elements like Al, K and Fe mirror the importance of the humid (fluvial) influence in the north of the study area and the dominance of aeolian input in the south. Furthermore, the distributions of Ti and Fe in the surface sediments serve as tracers for the supply of eolian volcanic material from the Canary Islands. The spatial variability of the TOC contents in the surface sediments closely follows the ocean surface productivity patterns, whereas the CaCO3 contents are mainly controlled by dilution with terrigenous matter. The potential productivity proxy Ba is not a reliable tracer for productivity in this region, since it is mainly supplied by terrigenous input (coupled with aluminosilicates).

Magnetic properties, grain sizes, XRF Scanner Data of sediment core GeoB9307-3

Geochemical and mineralogical proxies for paleoenvironmental conditions have the underlying assumption that climate variations have an impact on terrestrial weathering conditions. Varying properties of terrigenous sediments deposited at sea are therefore often interpreted in terms of paleoenvironmental change. Also in gravity core GeoB9307-3 (18° 33.99' S, 37° 22.89' E), located off the Zambezi River, environmental changes during Heinrich Stadial 1 (HS 1) and the Younger Dryas (YD) are accompanied by changing properties of the terrigenous sediment fraction. Our study focuses on the relationship of variability in the hydrological system and changes in the magnetic properties, major element geochemistry and granulometry of the sediments. We propose that changes in bulk sedimentary properties concur with environmental change, although not as a direct response of climate driven pedogenic processes. Spatial varying rainfall intensities on a sub-basin scale modify sediment export from different parts of the Zambezi River basin. During humid phases, such as HS 1 and the YD, sediment was mainly exported from the coastal areas, while during more arid phases sediments mirror the hinterland soil and lithological properties and are likely derived from the northern Shire sub-basin. We propose that a de-coupling of sedimentological and organic signals with variable discharge and erosional activity can occur.

Stable isotope ratios from foraminfera in Kara Sea sediments

Ostracods secrete their valve calcite within a few hours or days, therefore, its isotopic composition records ambient environmental conditions of only a short time span. Hydrographic changes between the calcification of individuals lead to a corresponding range (max.-min.) in the isotope values when measuring several (>=5) single valves from a specific sediment sample. Analyses of living (stained) ostracods from the Kara Sea sediment surface revealed high ranges of >2per mil of d18O and d13C at low absolute levels (d18O: <3per mil, d13C: <-3per mil) near the river estuaries of Ob and Yenisei and low ranges of not, vert, similar1per mil at higher absolute levels (d18O: 2-5.4per mil, d13C: -3 per mil to -1.5per mil) on the shelf and in submarine paleo-river channels. Comparison with a hydrographic data base and isotope measurements of bottom water samples shows that the average and the span of the ostracod-based isotope ranges closely mirror the long-term means and variabilities (standard deviation) of bottom water temperature and salinity. The bottom hydrography in the southern part of the Kara Sea shows strong response to the river discharge and its extreme seasonal and interannual variability. Less variable hydrographic conditions are indicative for deeper shelf areas to the north, but also for areas near the river estuaries along submarine paleo-river channels, which act as corridors for southward flowing cold and saline bottom water. Isotope analyses on up to five single ostracod valves per sample in the lower section (8-7 cal. ka BP) of a sediment core north of Yenisei estuary revealed d18O and d13C values which on average are lower by 0.6? in both, d18O and d13C, than in the upper core section (<5 cal. ka BP). The isotope shifts illustrate the decreasing influence of isotopically light river water at the bottom as a result of the southward retreat of the Yenisei river mouth from the coring site due to global sea level rise. However, the ranges (max.-min.) in the single-valve d18O and d13C data of the individual core samples are similar in the upper and in the lower core section, although a higher hydrographic variability is expected prior to 7 cal. ka BP due to river proximity. This lack of variability indicates the southward flow of cold, saline water along a submarine paleo-river channel, formerly existing at the core location. Despite shallowing of the site due to sediment filling of the channel and isostatic uplift of the area, the hydrographic variability at the core location remained low during the Late Holocene, because the shallowing proceeded synchronously with the retreat of the river mouth due to the global sea level rise

Annabella (El pentágono) de Antonio Di Benedetto : aproximaciones a una poética de la ficción

A partir de la idea de que las obras literarias pueden instaurar, dentro de su propia estructura, claros y profundos planteos sobre conceptos como realidad, ficción, y verdad ficcional. se indaga la poética de la ficción que de modo implícito se inscribe en la obra de Antonio Di Benedetto, más precisamente en El pentágono; novela en forma de cuentos, texto de corte experimental publicado por vez primera en 1955, en el que se presta especial atención a las relaciones entre realidad y ficción, a la posibilidad de la ficción de instituir mundos diversos y a los límites y juegos especulares entre ambos dominios. Por otra parte, se observa, en la peculiar construcción de esta novela en forma de cuentos, una estructura que en sí misma es signo del concepto de ficción que domina la obra.

Cocolos, emigración y narrativa dominicana

El desarrollo de la industria azucarera en la República Dominicana requirió mano de obra para el corte de caña y el trabajo en el ingenio. La dificultad en atraer trabajadores locales resultó en la contratación de obreros de las islas inglesas Anguila, St. Kitts, Antigua, Nevis, Tórtola, etc., donde el masivo desempleo provocado por la industrialización facilitaba el traslado de los isleños hacia las zafras dominicanas. En San Pedro de Macorís, lugar de su asentamiento, se los llamaba despectivamente “cocolos". Esta ponencia intenta estudiar la historia y delineación de estos obreros inmigrantes, su conducta, su idiosincrasia y modo de vida en el ingenio desde la narrativa dominicana del siglo XX. Las obras seleccionadas son un espejo del racismo, del rechazo cultural y de la explotación de los cocolos en el cañaveral. Cabe destacar que las novelas recientes asumen tardíamente una actitud reivindicatoria ante la ausencia de estudios críticos al respecto.

“Miram concordia et harmonia" : la relación naturaleza-persona en San Buenaventura

El presente trabajo muestra la analogía bonaventuriana en términos de distancia y espejo, señalando las instancias argumentativas a través de las cuales se llega al concepto de naturaleza entendido como expresión de Dios. Pero además, esta similitudo, a diferencia de la imagen, es cualidad pura común a todos los seres, y designa un modo eminente de participación en la perfección divina, que se imprime en un despliegue trinitario ad intra (Logos) a la vez que se expresa en la creación ad extra. Estos momentos metafísicos de impressio-expressio conforman la propia realidad divina y la posibilidad de acceso a ella por parte de la naturaleza participada. En la Distinción 25 de su Comentario a las Sentencias de Pedro Lombardo, Buenaventura hará uso de un concepto de analogía propio para explicar la relación entre Persona-divina y persona-creatura, en un ámbito ante todo metafísico que sobrepasa los aspectos preteológico y cosmológico. Por ello, además de permitirnos esclarecer la diferencia entre naturaleza y persona-creatura, la importancia de esta analogía planteada por Buenaventura radica en que proporciona una respuesta particular a la oposición naturaleza-Dios, en la que la diferencia no significa exclusión, sino, maravillosa concordia y harmonía".

En el espejo del Bicentenario

Se analizan condiciones históricas de la conformación de la Región del Noroeste argentino, con sus particulares características, así como incidencias del proceso revolucionario de 1810 y algunas repercusiones del mismo en el futuro de la Región. Se acude para ello al aporte de estudios históricos, lingüísticos y antropológicos regionales, así como al testimonio de pensadores comprometidos con su realidad. La población descendiente de los pueblos originarios aparece sumergida en situaciones de desigualdad y explotación a lo largo del período recorrido, lo que se expresa a través de obras de luchadores como M. A. Tanco, J. L. Torres y el grupo Tarja. En la actualidad, y a pesar de los avances realizados a nivel de Acuerdos y Declaraciones de organismos internacionales, la demanda de su legítimo y efectivo reconocimiento es una deuda pendiente, lo que conlleva connotaciones éticas que cuestionan las bases de nuestro sistema democrático.

Relatos verídicos : De la mentira a la ficción: La travesía ética de Luciano

Relatos Verídicos de Luciano de Samósata es una oportunidad para ver en acción a un escritor desobediente. Manifestar explícitamente su mentira para evidenciar, con sarcasmo y mucho de ironía, la actividad malintencionada de aquellos autores que engañan a su auditorio fue una decisión ética enmascarada con humor. Por esta razón, sostenemos que el samosatense promovió un acuerdo que llegaría intacto hasta nuestros días: Luciano inauguró el pacto ficcional con su lector. Mediante sus palabras, en el juego de espejos que propone el lenguaje, trazo una directriz de su conducta ética como escritor, decidió exponer su mentira para convertirla en verdad contribuyendo a la consolidación del nuevo terreno, la ficción. El auténtico camino de Luciano no condujo a la luna sino al deslinde entre la mentira y la ficción. Emprender aquella travesía escrituraria le permitió implantar un fundamento ético de sinceridad que, paradójicamente, postula el estadio perpetuo de lo verosímil

Ludopatía y estrategias narratológicas : El caso Barrios en Responso de Juan José Saer

Al inclinarse sobre Responso (1964), novela de los principios muchas veces considerada menor en la obra de Juan José Saer (1937-2005), el artículo muestra la relevancia del autor cuando describe los contornos psicológicos del jugador patológico Barrios. Se presentan las bases antropológicas del juego (Caillois) antes de tratar la ludopatía desde un enfoque clínico (Valleur y Bucher). Sigue un análisis narratológico que tiende a demostrar que algunos de los síntomas de la adicción al juego se alojan en una escritura ritmada por la asociación lúdica "diferencia y repetición" (Saer, La narración-objeto), y en la cual destacan figuras como la elipsis y la analepsis, que hacen de la forma literaria una suerte de espejo del juego patológico.

Benthic foraminifera in surface sediments of the Gulf of Lions

Surface sediment was sampled at two bathyal sites in the southwestern Gulf of Lions in the western Mediterranean Sea in February and August 1997 to study the distribution and microhabitat of living (Rose Bengal stained) deep sea benthic foraminifera. Both standing stock and diversity of the faunas, and the microhabitat of distinct species mirror the trophic situation and the depth of the oxidised layer at the different sites. Our results suggest that the faunas do not comprise highly opportunistic species and are adapted to rather stable environments. In the axial channel of the Lacaze-Duthiers Canyon, organic matter fluxes are enhanced due to advective transport of organic matter resulting in elevated oxygen consumption rates in the surface sediment and a rather thin oxidised layer. The corresponding benthic foraminiferal fauna is characterised by rather high standing stock and diversity, and a well-developed deep infauna. In addition to freshly deposited phytodetritus, more degraded organic matter seems to be an important food source. In contrast, at the open slope, organic matter fluxes and oxygen consumption rates in the surface sediment are lower and the oxidised layer is much thicker than inside the canyon. The corresponding benthic foraminiferal fauna comprises mainly epifaunal and shallow-infaunal species with much lower standing stocks and clear differences between February and August. In August standing stocks are higher and the average living depths of most species shift towards the sediment surface. These differences can be attributed to patchiness or represent a seasonal trophic signal.

Vanos ruidos de la lengua : La construcción del lenguaje poético en Eurípides

El análisis retórico tradicional del lenguaje poético de las tragedias de Eurípides ofrece frecuentemente el recuento de una variedad de recursos de estilo. Sin embargo, Eurípides propone una reflexión meta-discursiva acerca de la relación entre el objeto denominado y el nombre con el que se lo denomina, reintroduciendo de esta manera una autoconciencia de su quehacer literario. La cabal comprensión de este planteo meta-discursivo del trágico nos dará una clave que nos permitirá profundizar el sentido de sus usos retóricos. Intentaremos analizar este lenguaje poético euripideo en sus seis tragedias de tema bélico -Heraclidas, Hécuba, Troyanas, Helena, Suplicantes e Ifigenia en Áulide-, como una construcción intelectual autónoma que, en su complejidad retórica, intenta servir de herramienta y espejo (y, por tanto, de aproximación cognitiva) a la nueva contemplación del mundo que el final del siglo V propone

La novedad en las revistas de poesía: relatos de una tensión especular

En la sección de reseñas del Diario de poesía y Hablar de poesía, puede leerse el modo de ingreso de la novedad con signo diverso. Los libros de los poetas de los `90 serán abordados a partir de su singularidad, en el primero de los casos y desde la instalación fuerte en una tradición -la de la poesía argentina sesentista- en el segundo. De este modo, la idea de la novedad genera un movimiento especular. Hablar de poesía suele reseñar los libros desde una ideología sobre lo poético que podría definirse en términos de "lírica clásica", mientras que en el Diario de poesía se ponen en juego las premisas de la poesía moderna y contemporánea. En este sentido, la lectura de la novedad supone, en ambos casos, el diálogo con las poéticas que desarrollan aquellos que editan las revistas, cuyo resultado es la idea de una "paternidad joven" en el Diario y la necesidad de seleccionar y sustraer de una poética mayor en el de Hablar de poesía.