3,010 research outputs found
How Demanding Should Equality of Opportunity Be, and How Much Have We Achieved?
[Excerpt] This chapter proposes tests of various notions of equality of opportunity and applies them to intergenerational income data for the United States and Britain. Agreement is widespread that equality of opportunity holds in a society if the chances that individuals have to succeed depend only on their own efforts and not on extraneous circumstances that may inhibit or expand those chances. What is contentious, however, is what constitutes effort and circumstances. Most people, we think, would say that the social connections of an individual\u27s parents would be included among circumstances: equality of opportunity is incomplete if some individuals get ahead because they have well-connected parents. This and other channels through which circumstances affect income opportunities in an intergenerational context are discussed in Section 2.
Section 3 then formulates four, increasingly stringent criteria for equality of opportunity. In Section 4, we turn to an empirical implementation of these criteria to test for equality of opportunity in the United States and Britain. The results, presented in Section 5, provide only the weakest of support for equality of opportunity in the United States and no support at all in Britain.
Concluding remarks are presented in Section 6
Grassland and shrubland grasshopper community composition in northern La Pampa province, Argentina
Fil: Wysiecki, María Laura de. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; ArgentinaFil: Sánchez, Norma Elba. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; ArgentinaFil: Ricci, Susana E.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Humanas. Departamento de Sistemas Naturales y Ambiente; Argentin
A Three-Dimensional Dynamic Supramolecular "Sticky Fingers" Organic Framework.
Engineering high-recognition host-guest materials is a burgeoning area in basic and applied research. The challenge of exploring novel porous materials with advanced functionalities prompted us to develop dynamic crystalline structures promoted by soft interactions. The first example of a pure molecular dynamic crystalline framework is demonstrated, which is held together by means of weak "sticky fingers" van der Waals interactions. The presented organic-fullerene-based material exhibits a non-porous dynamic crystalline structure capable of undergoing single-crystal-to-single-crystal reactions. Exposure to hydrazine vapors induces structural and chemical changes that manifest as toposelective hydrogenation of alternating rings on the surface of the [60]fullerene. Control experiments confirm that the same reaction does not occur when performed in solution. Easy-to-detect changes in the macroscopic properties of the sample suggest utility as molecular sensors or energy-storage materials
Cellulose Nanofiber-Based Aerogels from Wheat Straw: Influence of Surface Load and Lignin Content on Their Properties and Dye Removal Capacity
Water pollution is one of the most serious problems worldwide. Nanocellulose-based aerogels usually show excellent adsorption capacities due to their high aspect ratio, specific surface area and surface charge, making them ideal for water purification. In this work, (ligno)cellulose nanofibers (LCNFs/CNFs) from wheat straw residues were obtained using two types of pre-treatments: mechanical (Mec) and TEMPO-mediated oxidization (TO), to obtain different consistency (0.2, 0.4, 0.6 and 0.8) bioaerogels, and their adsorption capacities as dye removers were further studied. The materials were characterized in terms of density, porosity and mechanical properties. An inversely proportional relationship was observed between the consistencies of the aerogels and their achieved densities. Despite the increase in density, all samples showed porosities above 99%. In terms of mechanical properties, the best results were obtained for the 0.8% consistency LCNF and CNF-Mec aerogels, reaching 67.87 kPa and 64.6 kPa for tensile strength and Young’s modulus, respectively. In contrast, the adsorption capacity of the aerogels was better for TEMPO-oxidized aerogels, reaching removal rates of almost 100% for the CNF-TO5 samples. Furthermore, the residual lignin content in LCNF-Mec aerogels showed a great improvement in the removal capacity, reaching rates higher than 80%, further improving the cost efficiency of the samples due to the reduction in chemical treatments
Hallazgo de una nueva columna miliaria perteneciente a la Via Augusta
By means of this article we let you know about the discovery of a new milliary column which belonged to the Roman Via Augusta. It has been found in the environs of La Torrecilla industrial area close to Córdoba. Its chronology based upon epigraphic analysis allow us to date it in the early years of Nero mandate.Mediante este artículo damos a conocer una nueva columna miliaria correspondiente a la Via Augusta y hallada en las inmediaciones del Polígono Industrial de La Torrecilla. Su cronología, basada en el análisis epigráfico, nos permite adjudicarla al emperador Nerón, en los primeros años de su mandato
Combined study of archaeomagnetism and Raman spectroscopy of experimentally burnt limestones from the middle-palaeolithic site of Pinilla del Valle (Madrid, Spain)
Se presentan los resultados arqueomagnéticos, de propiedades magnéticas y espectroscopia Raman obtenidos de analizar muestras de dos tipos de calizas calentadas experimentalmente bajo con-diciones controladas. Estas calizas han sido fre-cuentemente identificadas en los yacimientos de paleolítico medio de Cueva Descubierta y Abrigo de Navalmaíllo (Pinilla del Valle, Madrid, Es-paña). Mediante un sistema de termopares, se re-gistraron temperaturas máximas de calentamiento de 400-450 ºC durante una hora. El objetivo es caracterizar las variaciones en la mineralogía fe-rromagnética y los compuestos (in)orgánicos, así como estudiar el registro de la dirección del campo magnético terrestre en el momento del enfriamien-to. Esto permitirá obtener un patrón extrapolable a las calizas arqueológicas de cara a identificar estructuras de combustión en el yacimiento. Los experimentos de ambas técnicas fueron realizados en muestras representativas de ambas litologías tanto antes como después de la quema experimen-tal. Antes de la quema, ambos tipos de caliza es-taban dominados por dolomita y calcita y, como principales óxidos de hierro, goetita y magnetita. Tras la quema, la goetita original pervivió en las muestras calentadas <200 ºC mientras que se transformó a hematites y/o magnetita en las ca-lentadas en torno a 450 ºC. Las alteraciones mi-neralógicas se centraron mayoritariamente en el 1ercm de profundidad. La neoformación de magnetita como paso intermedio en el proceso de deshidra-tación de la goetita hacia hematites ha sido poco documentada y tiene implicaciones paleomagnéti-cas. Se discuten los resultados mineralógicos, sus implicaciones para la identificación de fuego en el yacimiento así como sus potenciales aplicaciones a casos de estudio similare.Here we report the archaeomagnetic,
rock-magnetic and Raman spectroscopy
results of sample analysis from two types
of limestones that were experimentally
heated under controlled conditions.
These lithologies have been commonly
identified at the middle-palaeolithic sites
of Descubierta Cave and Navalmaillo
rock-shelter (Pinilla del Valle, Madrid,
Spain). By means of a thermocouple system,
maximum heating temperatures of
400 − 450 ºC were recorded during one
hour. The main goal was to characterize
the variations in the magnetic mineralogy
and (in)organic compounds, and to
study the record of the Earth´s magnetic
field direction at the time of cooling.
This allowed us to obtain a pattern that
is potentially applicable to archaeological
limestones in order to identify combustion
structures at the site. All experiments were
carried out on representative samples
both before and after experimental heating.
Before heating, both types of limestones
were dominated by dolomite and
calcite and as main iron oxides, goethite
and magnetite. After heating, the original
goethite persisted in samples heated
to low temperatures (<200 ºC) whereas
it transformed to haematite and/or magnetite
in those heated to 450 ºC. Mineralogical
alterations mostly focused on the
outermost 1st cm of depth. The neoformation
of magnetite as intermediate step
in the dehydration process of goethite to
haematite has been barely documented
and has palaeomagnetic implications.
The mineralogical results obtained, their
implications for the identification of fire
at the site as well as potential applications
to similar cases studies are discussed.Junta de Castilla y León (projects BU066U16 and BU235P18) and the European Fund for Economic and Regional Development (FEDER
Evaluación de la calidad de vida en personas drogodopendientes mediante el modelo de Rasch
La Escala GENCAT aparece como el único instrumento que permite evaluar la calidad de vida individual de personas con drogodependencias desde una perspectiva diferente a la de calidad de vida relacionada con la salud (CVRS). Dado que las propiedades psicométricas de la mencionada escala sólo se han estudiado para la muestra general de usuarios de servicios sociales, este estudio tiene como objetivo analizar su fiabilidad y validez en un grupo específico de personas con drogodependencias. Para ello, se aplicó a 75 drogodependientes usuarios de servicios sociales en Cataluña. Los datos obtenidos permiten concluir que la escala, para este colectivo, presenta una adecuada consistencia interna (que supera en algunos casos la obtenida para la muestra general) según la Teoría Clásica de los Tests. Además, se observó que el ajuste medio de los ítems al modelo y la fiabilidad promedio de las estimaciones de los ítems fueron altos según el modelo de Rasch, aunque los índices de fiabilidad de las personas resultaron más moderados en la mayoría de las subescalas y deficiente en el caso de la dimensión bienestar físico. Se concluye que, aunque la escala es válida y fiable en términos generales, es aconsejable una revisión de la dimensión mencionada
Assessment of Rights-Related Personal Outcomes in Young People with Intellectual Disability and Autism Spectrum Disorder
Despite the great importance of the quality of life concept in the intellectual disability (ID) field, literature about its application to youth with autism spectrum disorder (ASD) is scarce, especially for the rights domain, an area that has become particularly important after the ratification of the Convention on the Rights of Persons with Disabilities. This study focuses on assessing the rights of youth with ASD and ID and comparing their results obtained by people with ID and other associated conditions: Down syndrome and cerebral palsy. The Rights subscale from the field-test version of the KidsLife Scale was administered in a sample composed of 153 participants with ID aged from 4 to 21 years old (ASD = 51; Down syndrome = 51; cerebral palsy = 51). The variables gender, type of schooling, level of ID and level of support needs were significant for the group with ASD. The three groups showed positive outcomes, though youth with Down syndrome obtained statistically significant higher scores than participants with ASD.Aun teniendo gran relevancia el concepto de calidad de vida en el ámbito de la discapacidad intelectual (DI), existe escasa investigación acerca de su aplicación en jóvenes con trastorno del espectro del autismo (TEA), especialmente acerca de la dimensión derechos, área que ha cobrado especial importancia en los últimos años con la ratificación de la Convención de los Derechos de las Personas con Discapacidad de Naciones Unidas. Este estudio se centra en la evaluación de derechos en jóvenes con TEA y DI, comparando sus resultados con dos grupos de jóvenes que presentan DI y otra condición comórbida: síndrome de Down y parálisis cerebral. Para ello, se utilizó la subescala derechos de la versión piloto de la Escala KidsLife en una muestra de 153 participantes con DI entre 4 y 21 años (TEA = 51; síndrome de Down = 51; parálisis cerebral = 51). En el grupo con TEA, el género, el tipo de escolarización, el nivel de DI y de necesidades de apoyo dieron lugar a diferencias significativas. Los tres grupos obtuvieron resultados positivos, aunque los jóvenes con síndrome de Down obtienen resultados significativamente superiores a los obtenidos por jóvenes con TEA
Origin and Control Strategies of Biofilms in the Cultural Heritage
Biodeterioration is defined as the undesirable change in the properties of materials caused by the activity of biological agents. This process is complex and involves alterations in the physicochemical and mechanical properties by the action of organisms and depends on the microorganisms involved, type of substrate, and environmental conditions. The biodeterioration of cultural heritage is the physical or chemical damage caused by microorganisms on objects, monuments, or buildings that belong to the cultural heritage. Among the main materials that can be affected are: stone, metal, ceramic, polymers, and other materials. Among the main undesirable effects to these materials are: discoloration, dissolution, rupture, and efflorescence among others. Biofilms represent the usual form of growth of bacteria and consist of communities of microorganisms that grow attached to an inert surface or a living tissue, surrounded by an extracellular matrix that they themselves synthesize. The importance of biodeterioration by biofilms is mainly related to changes in pH values, ionic concentrations, oxide-reduction reactions in the biofilm thickness, and in the interface with the substrate and enzymatic degradation. This chapter presents evidence of the participation of biofilms and associated mechanisms in biodeterioration as well as the main prevention and control strategies
Germination characteristics of Gymnocalycium monvillei (Cactaceae) along its entire altitudinal range
"Germination characteristics are important for understanding how species cope with environmental variation. The aims of this work were to analyze the effect of different temperatures (25 and 32 °C), water potentials (0, −0.2, −0.4, and −0.6 MPa), and light conditions (light vs. darkness) on the germination of five populations of the cactus Gymnocalycium monvillei (Lem.) Britton & Rose along its entire altitudinal distribution. The experiments to assess the effects of temperature, water potential, and light conditions were performed in germination chambers, and total germination (%) and mean germination time (T50) were recorded. Germination decreased in provenances from higher to lower altitudes, and the effect was very pronounced at temperatures of 32 °C. For all of the altitudinal provenances, germination decreased with lower water potential, with this effect being more pronounced at 32 °C. On the other hand, provenances at lower altitudes were less affected by lower water potentials than higher provenances. Provenances at all altitudes showed very low germination under dark conditions. T50 did not vary among altitudinal provenances at a temperature of 25 °C, but at 32 °C germination was slower at intermediate altitudes. Our results show that germination characteristics differ considerably among altitudinal provenances and seem to be important in determining the capacity of the species to inhabit such a broad gradient.
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