Collective identities, as literature suggests, are constructed via an emphasis on sameness within a group and in the downplaying of internal difference. This study, however, found that collective ...agency, and resultingly, collective identity, was fueled just as much by a careful negotiation of difference as it was a group’s core similarities. Based on interviews with Palestinian, Israeli, and international activists involved in two Palestinian-led coalitions in Israel/Palestine, the study shows how uneven privileges and other differences, could be leveraged for the benefit of the coalitions, particularly through assessing what each ethnonational group brought to the collective. When members enacted their closely negotiated and distinct roles, the coalition’s sense of “we” was further solidified. Indeed, as this article illustrates, difference as well as unequal privileges, can be perceived as a defining feature of a strategically constructed collective identity and the reason for a partnership, not simply a problem to be managed.
Proyecto FOCARIS, habitar la Luna Eid-Macheh-Sánchez, Yasmina; García-Valverde, Juanjo; Martínez-Frías, Jesús ...
Informes de la construcción,
03/2023, Letnik:
75, Številka:
569
Journal Article
Recenzirano
Odprti dostop
Contar con nuevos hábitats frente a la colonización de otros planetas surge de la motivación innata en los seres humanos de “traspasar fronteras”, llevando implícita la persecución del avance ...científico, tecnológico y sociocultural por medio del estudio y puesta en marcha de nuestras capacidades junto a la búsqueda de desarrollo. Así, Stephen Hawking encontraba necesario “ir donde nadie ha ido nunca aún”, con el fin de poder sobrevivir frente a “peligros y desastres” múltiples. En este sentido, proyectar y construir en base a las necesidades de máxima seguridad, confort, y mínimo consumo energético se hace necesario para cumplir, como decía Alvar Aalto (pionero en la arquitectura moderna), con “las plenas exigencias de una sociedad positiva”. Reflexiones estas, que ayudaron a plantear uno de los diez hábitats finalistas de un concurso internacional para el diseño de un futuro hábitat extraterrestre pensado con el fin de albergar vida humana en nuestro satélite, la Luna, denominada FOCARIS.
We review constraints on the magnitude and possible causes of discrepancies, or at least major disparities, among global and near‐global data sets for lunar highland surface composition. When ...compared with data from other sources, reported mafic mineral abundance results from the Kaguya Spectral Profiler (Kaguya SP) spectral reflectance method for four Apollo 16 soils appear systematically low by a factor of 0.6, or an even more extreme factor (~1/3) if viewed in relation to the soils’ nonglass or CIPW mineralogy. Also, whether evaluated on a global median basis or on the basis of site‐by‐site comparison (for Apollo 16, Luna 20, and Apollo 17), the compositions found by the Kaguya SP technique show discrepancy, or at least disparity, versus other mafic abundance observations by that same factor of ~1/3. Spectral reflectance does not supply a simple bulk analysis of the target soil. The reflectance mineralogical signal is preponderantly determined by the nonglass fraction, and especially the masswise subordinate 10–20 µm grain size fraction. Literature data show that in anorthositic lunar soil, chemical composition is fractionated, more extremely anorthositic, for the nonglass component compared to the glass component. Also, the grain size fraction (10–20 μm) that most closely matches bulk reflectance has a significantly higher abundance of impact/agglutinitic glass than does the coarser material that dominates the soil mass. The Kaguya SP mafic abundance calibration needs adjustment by a factor of nearly 3 if results are to be interpreted as indicative of the mineralogy of the underlying crust. A claimed detection of several hundred lunar 500 m scale purest anorthosite (PAN; ≥98 vol% plagioclase) locales among millions of spectral reflectance observations is dubious, in part because with large data sets, compositional extremes are inevitably exaggerated as a byproduct of analytical uncertainty. Preponderance of PAN composition is rare among terrestrial layered intrusive anorthosites and is neither required nor expected for the flotation crust of a global magma ocean. Buoyant flotation and compaction would not suffice to yield pure plagioclase unless adcumulus growth was negligible, and trace element contents of ferroan anorthosites show that their mafic silicate components are for the most part of adcumulus, not “trapped melt,” derivation. A PAN‐dominated crust would imply a curiously fractionated (low) thorium/aluminum ratio for the crust, an implausibly high mantle/crust Th concentration ratio, and an oddly low Th/Al for the bulk Moon. Remote sensing techniques for planetary regolith composition are not easy to calibrate, particularly near the extremes of composition‐space and sensitivity.
The influence of the particle size distribution (PSD) on the band broadening and the efficiency of packed columns is investigated on both theoretical and practical viewpoints. Each of the classical ...contributions to mass transfer kinetics, those due to longitudinal diffusion, eddy dispersion, and solid–liquid mass transfer resistance are measured and analyzed in terms of their expected and observed intensity as a function of the PSD of mixtures of the commercially available packing materials, 5 and 3
μm Luna-C
18(2) particles (Phenomenex, Torrance, CA, USA). Six 4.6
mm
×
150
mm columns were packed with different mixtures of these two materials. The efficiencies of these columns were measured for a non-retained and a retained analytes in a mixture of acetonitrile and water. The longitudinal diffusion coefficient was directly measured by the peak parking method. The solid–liquid mass transfer coefficient was measured from the combination of the peak parking method, the best model of effective diffusion coefficient and the actual PSDs of the different particle mixtures measured by Coulter counter experiments. The eddy diffusion term was measured according to a recently developed protocol, by numerical integration of the peak profiles. Our results clearly show that the PSD has no measurable impact on any of the coefficients of the van Deemter equation. On the contrary and surprisingly, adding a small fraction of large particles to a batch of small particles can improve the quality of the packing of the fine particles. Our results indirectly confirm that the success of sub-3
μm shell particles is due to the roughness of their external surface, which contributes to eliminate most of the nefarious wall effects.
The Terra-LUNA crash in May 2022 was triggered by the depeg of the ecosystem’s stablecoin UST. It led to the unprecedented demise of a blockchain ecosystem and cost investors tens of billions of ...dollars. We examined the impact of the Terra-LUNA crash on the cryptocurrency market. Based on the hourly return and realized volatility from April 2022 to May 2022, we used the spillover index and effective transfer entropy to configure the interlinkage change between cryptocurrency markets. We conclude that the Terra-LUNA crash had a significant impact on the connectedness of the cryptocurrency market, investor attention, and market sentiment.
•This paper is the first study of Terra-LUNA crash using the spillover index and transfer entropy.•We used the hourly prices, Google Trends index, and StockTwits to analyze the crash.•We confirmed that the Terra-LUNA crash had a significant impact on the the overall cryptocurrency market.
Types of rock, such as komatiite, which formed entirely or dominantly during restricted time periods in solar system history, are important indicators of how planetary bodies evolved in deep time. In ...this paper we characterize three different types of temporally-restricted anorthosites, and discuss their significance to the broad-scale evolution of planetary processes. Primordial anorthosites, which constitute the bulk of the lunar crust, were sampled during Apollo and Luna missions, and have subsequently been identified in our meteorite collections. They are characterized by very calcic plagioclase (An93–98), and all have magmatic crystallization ages >4.3Ga, suggesting that the earliest planetary crust-forming processes on the Moon, and possibly elsewhere, involved substantial, if not total melting. The “magma ocean” hypothesis, which has endured for nearly 50years, argues that the lunar anorthositic rocks represent global flotation cumulates of plagioclase, which crystallized after extensive precipitation and sinking of olivine and pyroxene. Another possibility, revitalized by critical filtering of age data, involves “serial magmatism”, whereby the lunar crust was constructed by younger, smaller, episodic magmatic events. On Earth, two distinct types of temporally-restricted anorthosites offer opportunities to understand the evolution of terrestrial geodynamics, tectonics and magmatic processes. Archean megacrystic anorthosites formed only between 3.73 and 2.49Ga as small bodies (<500km2) associated with the mafic magmatic assemblages of many greenstone belts. They are typified by accumulations of equidimensional, almost spherical megacrysts (1–30cm across) of calcic plagioclase (An61–94, avg. An80) in a mafic groundmass of broadly basaltic composition, and probably formed in shallow magma chambers. The unusually calcic plagioclase compositions may reflect crystallization from hydrous and/or Ca-rich basaltic parents that were fractionated derivatives of more primitive magmas, possibly even komatiites. Isotopic and geochemical data for many Archean anorthosite complexes indicate little to no evidence for contamination by silicic continental crust, suggesting magma formation in oceanic environments, most likely by subduction in oceanic arcs. Their temporal restriction might be explicable in terms of a hotter or wetter Archean mantle, especially if a genetic connection to komatiites can be demonstrated. Alternatively, higher Archean heat flow may have influenced oceanic crustal thickness, subduction rate, sites of magma generation and/or melt composition, producing favorable conditions for the generation of calcic megacrystic anorthosites. Proterozoic massif-type anorthosites are distinctly different from other anorthosite types, and occur as small plutons (1–10km2), to large (up to 18,000km2) composite batholiths, that are temporally restricted to a ~2000m.y. period between ~0.5 and ~2.6Ga. The rocks are dominated by lath-shaped, intermediate plagioclase (An30–70, avg. An53), with lesser pyroxenes and/or olivine. There is extensive evidence from petrology, geochemistry and isotope data for variable contamination with continental crust, and the most plausible physical model involves deep-crustal ponding of basaltic magmas, crystallization and sinking of mafic silicates, and eventual flotation of buoyant plagioclase. Massifs were constructed by the coalescence of plagioclase-rich mushes, which ascended to mid-crustal emplacement sites. The basaltic parent melts or magmas for massif-type anorthosites were mantle-derived; alternative models involving melting of crustal sources, mafic or otherwise, cannot be supported. Collective features most readily support an Andean-type continental arc setting, and careful geochronology is beginning to suggest that magmatism in individual massifs may have occurred over long time-scales of up to 100m.y. The onset of massif-type anorthosite formation at ~2.6Ga probably reflects global secular cooling of the Earth, resulting in increased lithospheric strength and crustal thickness, which promoted Moho-depth ponding and slow crystallization of basaltic magmas in continental arc environments. The apparent disappearance of anorthosite massifs at ~0.5Ga may also relate to global secular cooling that changed the thermal structure of subduction zones, and promoted the onset of high and ultra-high pressure metamorphism.
INTRODUCCIÓN: En muchas sociedades alrededor del mundo existe una creencia que relaciona el ciclolunar con la frecuencia de nacimientos, especialmente debido a la influencia de la luna llena. Aunque ...lamayoría de los estudios no encuentran relación entre las diferentes fases lunares y la frecuencia de partosespontáneos, sigue existiendo esta creencia incluso entre profesionales de la salud.OBJETIVO: Demostrar el aumento de porcentaje de nacimientos por partos espontáneos durante la lunallena comparado con las otras fases, describir el porcentaje de nacimientos en cada fase lunar, mencionarla distribución de nacimientos según sexo, mostrar la distribución de nacimientos según edad gestacional,conocer cantidad de trabajos de parto terminados en cesárea o en parto vaginal y registrar lascomplicaciones en cada fase lunar.MATERIAL Y MÉTODO: Estudio de cohorte, retrospectivo, observacional y analítico. La población estáconstituida por embarazadas que ingresen a nuestra Institución en trabajo de parto espontáneo. El tiempocomprendido es entre el 01/01/2021 hasta el 31/01/2022. Los datos se obtienen del Libro de parto delServicio de Tocoginecología de la Clínica. El análisis de datos se realiza mediante el cálculo de la media,mediana y cuartiles para las variables categóricas, utilizando el software R, versión x644.1.1 y el Test deChi2.RESULTADO: Entre enero del año 2021 a 2022, hay anotados un total 1003 nacimientos de partosdesencadenados en forma espontánea, incluyendo aquellos tanto a término como pretérmino. No sedemostró una diferencia estadística en la distribución de nacimientos por sexos entre las diferentes faseslunares (P < 0,8). Teniendo en cuenta las edades gestacionales, la mediana es de 39 semanas, la media de38,5 semanas, mínima, 22 semanas y la máxima, 41,4 semanas. Con respecto a la distribución de la cantidadde nacimientos con las diferentes fases lunares, obtuvimos que durante la fase de Luna Nueva el total es de275 (27,4%), en la fase Cuarto Creciente de 212 (21,1%), en Luna Llena de 264 (26,3%) y en CuartoMenguante de 252 (25,1%) (P< 0,3), no encontrándose diferencias estadísticas significativas entre lasvariables. No se encontró una relación estadística significativa entre las variables de cantidad denacimientos y las distintas fases lunares. Cuando analizamos las complicaciones y observaciones del trabajode parto presentadas, se obtuvo que la cantidad de las mismas fueron 176. Siendo la más frecuente la roturaprematura de membranas, con un total de 162 casos (92%), aunque no se objetiva una diferenciasignificativa entre la incidencia de las complicaciones en las diferentes fases lunares (P <0,5).CONCLUSIONES: A pesar de las numerosas investigaciones llevadas a cabo, el mito de las fases lunaresaún se encuentra extendido geográficamente, y continúa transmitiéndose a lo largo de las generaciones,formando parte del folclore de nuestra comunidad. En escasos trabajos de investigación en donde seestableció un aumento de la incidencia de nacimientos, no hubo consenso de que fase lunar es la másinfluyente.
Dentro de la literatura revisada, el análisis llevado a cabo por Gutziunaite y col. demostró mayortasa de nacimientos durante la fase de luna llena.Nuestros resultados no mostraron diferencias significativas con respecto a los nacimientos en las distintasfases lunares.Dentro de las limitaciones de este estudio, se incluyen los sesgos de selección y de información, ya que setrata de un estudio de tipo observacional. Por otro lado, no se analizaron resultados como abortosespontáneos y evacuaciones del segundo trimestre dentro de las complicaciones.
Measuring the spatial density of craters emplaced on geologic units is the primary method used for remotely estimating ages of solar system surfaces. The calibration for this method, which enables ...conversion of crater density to absolute age, comes from Apollo and Luna lunar samples for which absolute radiometric ages have been determined. Researchers throughout the 1970s worked to establish the lunar chronology system based on that calibration, correlating crater densities with absolute ages. However, no uniform crater study has been conducted on all calibration terrains, a limitation that was previously unaddressed until this study. The latest lunar images from the Lunar Reconnaissance Orbiter were used here to re-map the eleven main sampling sites and new crater counts of those surfaces were conducted. These show significant differences for many sites' crater counts, in many cases having more craters than previously identified. These results, calibrated to the radiometric ages, show a revised lunar crater chronology that changes previously established crater-based ages by up about 1 billion years: Surfaces younger than ∼3.6 Gyr and older than ∼3.9 Gyr under the classic chronology are younger in this system, and those in-between are older in this new system.
•New mapping and crater counts of Apollo and Luna chronology calibration sites.•Most sites have a higher density of ≥1-km-diameter craters than previous work.•Some ages dated via craters are up to 1.1 Gyr younger than previously thought.
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