Synthesis and characterization of La_0.8Sr_1.2Co_0.5M_0.5O_4-? (M=Fe, Mn)

The M4+-containing K2NiF4-type phases La0.8Sr1.2Co0.5Fe0.5O4 and La0.8Sr1.2Co0.5Mn0.5O4 have been synthesized by a sol-gel procedure and characterized by X-ray powder diffraction, thermal analysis, neutron powder diffraction and Mössbauer spectroscopy. Oxide ion vacancies are created in these materials via reduction of M4+ to M3+ and of Co3+ to Co2+. The vacancies are confined to the equatorial planes of the K2NiF4-type structure. A partial reduction of Mn3+ to Mn2+ also occurs to achieve the oxygen stoichiometry in La0.8Sr1.2Co0.5Mn0.5O3.6. La0.8Sr1.2Co0.5Fe0.5O3.65 contains Co2+ and Fe3+ ions which interact antiferromagnetically and result in noncollinear magnetic order consistent with the tetragonal symmetry. Competing ferromagnetic and antiferromagnetic interactions in La0.8Sr1.2Co0.5Fe0.5O4, La0.8Sr1.2Co0.5Mn0.5O4 and La0.8Sr1.2Co0.5Mn0.5O3.6 induce spin glass properties in these phases

A social compromise for the anthropocene? : elite reactions to the Escazú Agreement and the prospects for a Latin American transformative green state

Números monográficos con título distintivo catalogados individualmente.‎Bajo la denominación "Documentos de trabajo" se publican resultados de los proyectos de investigación realizados y promovidos por el CEALCI. Además pueden ser incluidos en esta serie aquellos trabajos que, previa aceptación por el Consejo Editorial, reunan los requisitos de calidad establecidos y coincidan con los objetivos de la Fundación Carolina y su Centro de Estudios.‎Bibliografía: p. 20-25Resumen: El mundo enfrenta con urgencia la necesidad de una “transformación verde”, que implica no solo una transición hacia el uso de energías renovables y la reducción de la pérdida de biodiversidad, sino también un profundo cambio social hacia la justicia social y la sostenibilidad. Ello requiere de compromisos sociales entre élites y sectores populares que permitan construir instituciones fuertes para implementar cambios. América Latina afronta enormes desafíos para aumentar la igualdad, la justicia y la sostenibilidad, pero también puede jugar un papel fundamental en la transformación verde global. La región también se caracteriza por tener élites robustas, fuertes movimientos socioambientales y profundos conflictos ambientales, que dificultan los compromisos sociales. Este documento analiza las reacciones de las élites al acuerdo regional más avanzado sobre regulación ambiental y resolución de conflictos, el Acuerdo de Escazù. En muchos países, las élites se opusieron con vehemencia, arguyendo la injerencia sobre su soberanía nacional, pero rechazando particularmente las implicaciones institucionales del acuerdo que suponen un mayor compromiso para permitir la participación popular. A esto se opusieron las élites económicas de los países democráticos (Chile, Colombia, Costa Rica y Perú), así como las élites gubernamentales de los países autoritarios (El Salvador y Venezuela). Sin embargo, en varios casos, la oposición de las élites fue superada gracias a la movilización social y al diálogo. Este documento analiza los aprendizajes de las reacciones de las élites al Acuerdo de Escazú ante futuros compromisos sociales como base para el surgimiento de Estados transformadores en América Latina

The Phenotype-Fitness Map in Experimental Evolution of Phages

Evolutionary biologists commonly interpret adaptations of organisms by reference to a phenotype-fitness map, a model of how different states of a phenotype affect fitness. Notwithstanding the popularity of this approach, it remains difficult to directly test these mappings, both because the map often describes only a small subset of phenotypes contributing to total fitness and because direct measures of fitness are difficult to obtain and compare to the map. Both limitations can be overcome for bacterial viruses (phages) grown in the experimental condition of unlimited hosts. A complete accounting of fitness requires 3 easily measured phenotypes, and total fitness is also directly measurable for arbitrary genotypes. Yet despite the presumed transparency of this system, directly estimated fitnesses often differ from fitnesses calculated from the phenotype-fitness map. This study attempts to resolve these discrepancies, both by developing a more exact analytical phenotype-fitness map and by exploring the empirical foundations of direct fitness estimates. We derive an equation (the phenotype-fitness map) for exponential phage growth that allows an arbitrary distribution of lysis times and burst sizes. We also show that direct estimates of fitness are, in many cases, plausibly in error because the population has not attained stable age distribution and thus violates the model underlying the phenotype-fitness map. In conjunction with data provided here, the new understanding appears to resolve a discrepancy between the reported fitness of phage T7 and the substantially lower value calculated from its phenotype-fitness map

Mechanical Forces in Floral Development

Mechanical forces acting within the plant body that can mold flower shape throughout development received little attention. The palette of action of these forces ranges from mechanical pressures on organ primordia at the microscopic level up to the twisting of a peduncle that promotes resupination of a flower at the macroscopic level. Here, we argue that without these forces acting during the ontogenetic process, the actual flower phenotype would not be achieved as it is. In this review, we concentrate on mechanical forces that occur at the microscopic level and determine the fate of the flower shape by the physical constraints on meristems at an early stage of development. We thus highlight the generative role of mechanical forces over the floral phenotype and underline our general view of flower development as the sum of interactions of known physiological and genetic processes, together with physical aspects and mechanical events that are entangled towards the shaping of the mature flower.info:eu-repo/semantics/publishedVersio

Evaluation of plant biomass resources available for replacement of fossil oil

The potential of plants to replace fossil oil was evaluated by considering the scale of production required, the area of land needed and the types of plants available. High yielding crops (50 tonnes/ha) that have a high conversion efficiency (75%) would require a global land footprint of around 100 million ha to replace current (2008) oil consumption. Lower yielding or less convertible plants would require a larger land footprint. Domestication of new species as dedicated energy crops may be necessary. A systematic analysis of higher plants and their current and potential uses is presented. Plant biotechnology provides tools to improve the prospects of replacing oil with plant-derived biomass by increasing the amount of biomass produced per unit area of land and improving the composition of the biomass to increase the efficiency of conversion to biofuel and biomaterials. Options for the production of high value coproducts and the expression of processing aids such as enzymes in the plant may add further value to plants as bioenergy resources

¿Un compromiso social para el Antropoceno? : reacciones de las élites al Acuerdo de Escazú y las posibilidades de un Estado verde transformador latinoamericano

Números monográficos con título distintivo catalogados individualmente.‎Bajo la denominación "Documentos de trabajo" se publican resultados de los proyectos de investigación realizados y promovidos por el CEALCI. Además pueden ser incluidos en esta serie aquellos trabajos que, previa aceptación por el Consejo Editorial, reunan los requisitos de calidad establecidos y coincidan con los objetivos de la Fundación Carolina y su Centro de Estudios.‎Bibliografía: p. 22-27Resumen: El mundo enfrenta con urgencia la necesidad de una “transformación verde”, que implica no solo una transición hacia el uso de energías renovables y la reducción de la pérdida de biodiversidad, sino también un profundo cambio social hacia la justicia social y la sostenibilidad. Ello requiere de compromisos sociales entre élites y sectores populares que permitan construir instituciones fuertes para implementar cambios. América Latina afronta enormes desafíos para aumentar la igualdad, la justicia y la sostenibilidad, pero también puede jugar un papel fundamental en la transformación verde global. La región también se caracteriza por tener élites robustas, fuertes movimientos socioambientales y profundos conflictos ambientales, que dificultan los compromisos sociales. Este documento analiza las reacciones de las élites al acuerdo regional más avanzado sobre regulación ambiental y resolución de conflictos, el Acuerdo de Escazù. En muchos países, las élites se opusieron con vehemencia, arguyendo la injerencia sobre su soberanía nacional, pero rechazando particularmente las implicaciones institucionales del acuerdo que suponen un mayor compromiso para permitir la participación popular. A esto se opusieron las élites económicas de los países democráticos (Chile, Colombia, Costa Rica y Perú), así como las élites gubernamentales de los países autoritarios (El Salvador y Venezuela). Sin embargo, en varios casos, la oposición de las élites fue superada gracias a la movilización social y al diálogo. Este documento analiza los aprendizajes de las reacciones de las élites al Acuerdo de Escazú ante futuros compromisos sociales como base para el surgimiento de Estados transformadores en América Latina

Transition outcomes for young people discharged from adolescent medium secure services in England : a qualitative study exploring adolescents' and carers' experiences

Background: Young people in secure services present with multiple vulnerabilities, therefore transition periods are especially challenging for this group. In this study we followed up young people discharged from adolescent medium secure services to adult and community settings with the aim to explore transition experiences and outcomes. Methods: Participants were recruited from 15 child and adult mental health services in England. We conducted qualitative semi-structured interviews with 13 young people, aged 18 -19 years, moving from child and adolescent medium secure units two to six months post-transition, and five carers one to three months pre-transition. Thematic analysis was performed to identify predetermined or data-driven themes elicited from face-to-face interviews. Results: The findings indicated poor transition outcomes for young people with the most severe mental health symptoms and those who committed serious offences. Three overarching themes were identified: (1) unsettling environmental factors within adult services; (2) experiences of transition management and preparation; and (3) parental experiences of transition process and engagement with adult services. Conclusion: The findings of this study indicate that young people and carers value ongoing involvement in the transition process by well-informed parallel care. They also highlight the need for a national integrative care model that diverges from the traditional ‘one-size-fits-all’ approach

Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

The Konkola deposit is a high grade stratiform Cu–Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper–cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irregular veins. The hypogene sulphide mineralogy consists predominantly of chalcopyrite, bornite and chalcocite. Based upon relationships with metamorphic biotite, vein sulphides and most of the sulphides in cemented lenses were precipitated during or after biotite zone greenschist facies metamorphism. New δ34S values of sulphides from the Konkola deposit are presented. The sulphur isotope values range from −8.7‰ to +1.4‰ V-CDT for chalcopyrite from all mineralising phases and from −4.4‰ to +2.0‰ V-CDT for secondary chalcocite. Similarities in δ34S for sulphides from different vein generations, earlier sulphides and secondary chalcocite can be explained by (re)mobilisation of S from earlier formed sulphide phases, an interpretation strongly supported by the petrographic evidence. Deep supergene enrichment and leaching occurs up to a km in depth, predominantly in the form of secondary chalcocite, goethite and malachite and is often associated with zones of high permeability. Detailed distribution maps of total copper and total cobalt contents of the Ore Shale formation show a close relationship between structural features and higher copper and lower cobalt contents, relative to other areas of the mine. Structural features include the Kirilabombwe anticline and fault zones along the axial plane and two fault zones in the southern limb of the anticline. Cobalt and copper behave differently in relation to these structural features. These structures are interpreted to have played a significant role in (re)mobilisation and concentration of the metals, in agreement with observations made elsewhere in the Zambian Copperbelt

Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged. © 2013 Lombardo et al

Protection from Lethal Gram-Positive Infection by Macrophage Scavenger Receptor–Dependent Phagocytosis

Infections with gram-positive bacteria are a major cause of morbidity and mortality in humans. Opsonin-dependent phagocytosis plays a major role in protection against and recovery from gram-positive infections. Inborn and acquired defects in opsonin generation and/or recognition by phagocytes are associated with an increased susceptibility to bacterial infections. In contrast, the physiological significance of opsonin-independent phagocytosis is unknown. Type I and II class A scavenger receptors (SR-AI/II) recognize a variety of polyanions including bacterial cell wall products such as lipopolysaccharide (LPS) and lipoteichoic acid (LTA), suggesting a role for SR-AI/II in innate immunity to bacterial infections. Here, we show that SR-AI/II–deficient mice (MSR-A−/−) are more susceptible to intraperitoneal infection with a prototypic gram-positive pathogen, Staphylococcus aureus, than MSR-A+/+ control mice. MSR-A−/− mice display an impaired ability to clear bacteria from the site of infection despite normal killing of S. aureus by neutrophils and die as a result of disseminated infection. Opsonin-independent phagocytosis of gram-positive bacteria by MSR-A−/− macrophages is significantly decreased although their phagocytic machinery is intact. Peritoneal macrophages from control mice phagocytose a variety of gram-positive bacteria in an SR-AI/II–dependent manner. Our findings demonstrate that SR-AI/II mediate opsonin-independent phagocytosis of gram-positive bacteria, and provide the first evidence that opsonin-independent phagocytosis plays a critical role in host defense against bacterial infections in vivo