961 resultados para Initiales historiées
Resumo:
Investigations of geomorphology, geoarchaeology, pollen, palynofacies, and charcoal indicate the comparative scales and significance of palaeoenvironmental changes throughout the Holocene at the junction between the hyper-arid hot Wadi â??Arabah desert and the front of the Mediterranean-belt Mountains of Edom in southern Jordan through a series of climatic changes and episodes of intense mining and smelting of copper ores. Early Holocene alluviation followed the impact of Neolithic grazers but climate drove fluvial geomorphic change in the Late Holocene, with a major arid episode corresponding chronologically with the â??Little Ice Ageâ?? causing widespread alluviation. The harvesting of wood for charcoal may have been sufficiently intense and widespread to affect the capacity of intensively harvested tree species to respond to a period of greater precipitation deduced for the Roman-Byzantine period - a property that affects both taphonomic and biogeographical bases for the interpretation of palynological evidence from arid-lands with substantial industrial histories. Studies of palynofacies have provided a record of human and climatic causes of soil erosion, and the changing intensity of the use of fire over time. The patterns of vegetational, climatic change and geomorphic changes are set out for this area for the last 8000 years.
Resumo:
In the case of a simple quantum system, we investigate the possibility of defining meaningful probabilities for a quantity that cannot be represented by a Hermitian operator. We find that the consistent-histories approach, recently applied to the case of quantum traversal time [N. Yamada, Phys. Rev. Lett. 83, 3350 (1999)], does not provide a suitable criterion and we dispute Yamada's claim of finding a simple solution to the tunneling-time problem. Rather, we define the probabilities for certain types of generally nonorthogonal decomposition of the system's quantum state. These relate to the interaction between the system and its environment, can be observed in a generalized von Neumann measurement, and are consistent with a particular class of positive-operator-valued measures.
Resumo:
Background Interferon ? receptor 1 (IFN? R1) deficiency is a primary immunodeficiency with allelic dominant and recessive mutations characterised clinically by severe infections with mycobacteria. We aimed to compare the clinical features of recessive and dominant IFN?R1 deficiencies. Methods We obtained data from a large cohort of patients worldwide. We assessed these people by medical histories, records, and genetic and immunological studies. Data were abstracted onto a standard form. Findings We identified 22 patients with recessive complete IFN?R1 deficiency and 38 with dominant partial deficiency. BCG and environmental mycobacteria were the most frequent pathogens. In recessive patients, 17 (77%) had environmental mycobacterial disease and all nine BCG-vaccinated patients had BCG disease. In dominant patients, 30 (79%) had environmental mycobacterial disease and 11 (73%) of 15 BCG-vaccinated patients had BCG disease. Compared with dominant patients, those with recessive deficiency were younger at onset of first environmental mycobacterial disease (mean 3·1 years [SD 2·5] vs 13·4 years [14·3], p=0·001), had more mycobacterial disease episodes (19 vs 8 per 100 person-years of observation, p=0·0001), had more severe mycobacterial disease (mean number of organs infected by Mycobacterium avium complex 4·1 [SD 0·8] vs 2·0 [1·1], p=0·004), had shorter mean disease-free intervals (1·6 years [SD 1·4] vs 7·2 years [7·6], p
Resumo:
Despite strong evidence of high rates of childhood and adult trauma in schizophrenia, the area remains under-researched. Our objectives in the study were first, to examine the rates of exposure to childhood, adult and lifetime (child plus adult) trauma in a population with schizophrenia and a population with non-psychotic psychiatric diagnoses and second, to examine the effect of trauma on the symptoms of schizophrenia. Two groups, those with schizophrenia (n = 40), and those with a non-psychotic diagnosis (n = 30), were recruited. Data were collected for demographic, psychiatric and trauma histories for all participants and on psychosocial functioning and psychiatric symptomatology for the patients with schizophrenia. Childhood exposure to trauma was significantly more common in the schizophrenia group (t = 5.196, df = 68, p <0.001, Eta squared = 0.28), with the strongest relationship being childhood physical assault. In the schizophrenia group a history of trauma was significantly related to poor communication skills (r = -0.529, p <0.001) and depressive symptoms (r = 0.443, p = 0.004). Evidence that childhood exposure to trauma is more common in a population with schizophrenia is consistent with other studies and raises the possibility that such trauma is of etiological importance. Further research is required to replicate those findings, to elucidate possible pathways by which the experience of trauma may contribute to the development of schizophrenia, and to explore the relationship between a history of childhood trauma and the experience of depressive symptoms in schizophrenia.
Resumo:
A pesar de la progresiva introducción de nuevos recursos en las aulas fruto del desarrollo de las TICs, el libro de texto sigue siendo uno de los materiales más utilizado y cuyo protagonismo en la configuración de la práctica escolar ha sido decisivo, por lo que debe ocupar nuestra atención en la formación inicial de los profesionales de la educación. Durante los cursos académicos 2012-13 y 13-14, hemos realizado en el marco de la asignatura de Análisis y diseño de materiales para la educación y la formación del tercer curso del grado de Pedagogía de la Universidad de Oviedo una práctica formativa de análisis de libros de texto escolares que nos ha permitido analizar contextualizadamente y desde una perspectiva teórico-práctica, cuestiones tales como: papel del profesorado en el desarrollo e innovación del currículum, papel de las editoriales en la interpretación del currículum oficial, análisis de tareas y mensajes en los manuales escolares, criterios para juzgar la calidad didáctica de los materiales, etc. El análisis cualitativo de treinta informes desarrollados por 120 estudiantes sobre diferentes libros de texto nos ha permitido identificar sus principales fortalezas y debilidades en varias dimensiones (aspectos formales, metodología, mensajes, implicaciones para la profesionalidad docente) y nos permite concluir que se trata de una experiencia formativa relevante en la formación inicial de cualquier profesional de la educación.
Resumo:
Fire has long been recognized as an agent of rock weathering. Our understanding of the impact of fire on stone comes either from early anecdotal evidence, or from more recent laboratory simulation studies, using furnaces to simulate the effects of fire. This paper suggests that knowledge derived from simulated heating experiments is based on the preconceptions of the experiment designer – when using a furnace to simulate fire, the operator decides on the maximum temperature and the duration of the experiment. These are key factors in determining the response of the stone to fire, and if these are removed from realworld observations then knowledge based on these simulations must be questioned. To explore the differences between heating sandstone in a furnace and a real fire, sample blocks of Peakmoor Sandstone were subjected to different stress histories in combination (lime rendering and removal, furnace heating or fire, frost and salt weathering). Block response to furnace heating and fire is discussed, with emphasis placed on the non-uniformity of the fire and of block response to fire in contrast to the uniform response to surface heating in a furnace. Subsequent response to salt weathering (by a 10% solution of sodium chloride and magnesium sulphate) was then monitored by weight loss. Blocks that had experienced fire showed a more unpredictable response to salt weathering than those that had undergone furnace heating – spalling of corners and rapid catastrophic weight loss were evidenced in blocks that had been subjected to fire, after periods of relative quiescence. An important physical side-effect of the fire was soot accumulation, which created a waxy, relatively impermeable layer on some blocks. This layer repelled water and hindered salt ingress, but eventually detached when salt, able to enter the substrate through more permeable areas, concentrated and crystallized behind it, resulting in rapid weight loss and accelerated decay. Copyright ©2007 John Wiley & Sons, Ltd.
Resumo:
This paper describes the incidence of maltreatment histories in a community sample of mothers of one-year old infants in Northern Ireland. The occurrence of five subsets of childhood maltreatment is examined: emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse. Of the 201 women who completed the Childhood Trauma Questionnaire (CTQ), 70 mothers (35%) reported experiencing one or more types of maltreatment during childhood. Forty-eight mothers (24%) gave a history of being emotionally abused, 43 (21%) of emotional neglect, 27 (13%) of physical abuse, 20 (10%) of sexual abuse, and 19 (10%) of physical neglect. Physical abuse was the only type of maltreatment which showed an association with maternal socio-economic status, with higher incidence reported amongst Occupational Classes 4 and 5 (lower supervisory and technical occupations and semi-routine and routine groups). More than half of those with a history of abuse experienced more than one type of maltreatment (42 mothers or 60% of those reporting maltreatment). Differences in rates of incidence to more recent studies on younger adults are discussed, as well as implications for prevention and intervention.
Resumo:
We review the uses of fossil insects, particularly Coleoptera (beetles) and Chironomidae (non-biting midges) from ancient deposits to inform the study of wetland ecosystems and their ecological and restoration processes. In particular, we focus on two contrasting ecosystems, drawing upon research undertaken by us on British raised mire peats and shallow lake systems, one an essentially terrestrial ecosystem, the other aquatic, but in which wetland insects play an important and integral part. The study of raised mire peats suggests that faunal stability is a characteristic of these wetland systems, over what appear to be extensive periods of time (up to several millennia), whilst studies of shallow lake ecosystems over recent timescales indicates that faunal instability appears to be more common, usually driven by increasing eutrophication. Drawing upon a series of fossil Coleoptera records spanning several thousand years from Hatfield Moors, south Yorkshire, we reconstruct in some detail the mire’s ontogeny and fluctuations in site hydrology and vegetation cover, illustrating the intimate association between substrate, topography and peat development. A comparison between fossil and modern beetle populations indicates that the faunal characteristics of this mire and its adjacent neighbour, Thorne Moors, become established during the early phases of peat development, including its rare endemics, and that the faunal biodiversity on the sites today is dictated by complex site histories. The over-riding characteristic of these faunas is of stability over several thousand years, which has important implications for the restoration of degraded sites, especially those where refugial areas are limited. In contrast, analyses of fossil Chironomidae from shallow lakes allow researchers to track changes in limnological status and while attempts have been made to reconstruct changes in nutrient levels quantitatively, the chironomids respond indirectly to such changes, typically mediated through complex ecosystem dynamics such as changes in fish and/or macrophyte communities. These changes are illustrated via historic chironomid stratigraphies and diversity indices from a range of shallow lakes located across Britain: Slapton Ley, Frensham Great Pond, Fleet Pond, Kyre Pool and Barnes Loch. These sites have shown varying degrees of eutrophication over recent timescales which tends to be associated with a decline in chironomid diversity. While complex functional processes exist within these ecosystems, our evidence suggests that one of the key drivers in the loss of shallow lake chironomid diversity appears to be the loss of aquatic macrophytes. Overall, while chironomids do show a clear response to altered nutrient regimes, multi-proxy reconstructions are recommended for a clear interpretation of past change. We conclude that if we are to have a better understanding of biota at the ecosystem level we need to know more of the complex interactions between different insect groups as well as with other animal and plant communities. A palaeoecological approach is thus crucial in order to assess the role of insect groups in ecosystem processes, both in the recent past and over long time scales, and is essential for wetland managers and conservation organisations involved in long term management and restoration of wetland systems.
Resumo:
The glacial episodes of the Quaternary (2.6 million years ago–present) were a major factor in shaping the present-day distributions of extant flora and fauna, with expansions and contractions of the ice sheets rendering large areas uninhabitable for most species. Fossil records suggest that many species survived glacial maxima by retreating to refugia, usually at lower latitudes. Recently, phylogeographic studies have given support to the existence of previously unknown, or cryptic, refugia. Here we summarise many of these insights into the glacial histories of species in cryptic refugia gained through phylogeographic approaches. Understanding such refugia might be important as the Earth heads into another period of climate change, in terms of predicting the effects on species distribution and survival.
Resumo:
Sería imposible hacer una enumeración de festejos, espectáculos y representaciones teatrales, que a lo largo de la época moderna, tuvieron como argumento las historias narradas por la literatura homérica. Incontables, pero todas ellas buscaban el don de la elocuencia que tenían desde que en la Antigüedad empezaron a reeditarse. Apenas un iglo después de la recopilación de relatos orales que quedaron hilvanados bajo los títulos de la Iliada y la Odisea –si se acepta la autoría de ese personaje mítico que fue Homero en torno al siglo VIII antes de Cristo–, tiranos y oligarcas atisbaron de forma visionaria las posibilidades que aportaban las tramas en las que se vieron envueltos dioses y héroes. La mitología olímpica no sólo sirvió al propósito de la unificación panhelénica de la nación de naciones que era Grecia, en torno a un mundo de creencias común en el marco de los grandes santuario, sino que además, las vicisitudes de los principales personajes, como Paris, Aquiles, Héctor, Ulises, Pentesilea, Eneas, Agamenón, Andrómaca, Casandra y Helena, proporcionaron un repertorio de modelos de conducta y un protocolo ceremonial en sociedad extremadamente útil. Piedad, fidelidad, excelencia, belleza, sumisión, virtudes morales que habían de “adornar” por igual a gobernantes y a ciudadanos, garantizaban un nuevo orden en la Hélade, constituyendo asimismo las notas distintivas con respecto a los anquilosados y monolíticos Imperios hegemónicos en la zona de Oriente Próximo, Egipcio y Babilónico o Persa, respectivamente. Se propone el análisis de la incidencia iconológica de tales asuntos a partir de la revisión escenográfica de dos libretos para dos representaciones teatrales italianas de finales del Seicento, de los que se encuentran sendos ejemplares en la Biblioteca Nacional de Madrid: Il Greco in Troia y La caduta del regno dell´amazzone.
Resumo:
In Ireland, the Middle to Late Bronze Age (1500-600 cal. B.C.) is characterised by alternating phases of prolific metalwork production (the Bishopsland and Dowris Phases) and apparent recessions (the Roscommon Phase and the Late Bronze Age-Iron Age transition). In this paper, these changes in material culture are placed in a socio-economic context by examining contemporary settlement and land-use patterns interpreted from the pollen record. The vegetation histories of six tephrochronologically-linked sites are presented that provide high-resolution and chronologically well-resolved insights into changes in landscape use over the Middle to Late Bronze Age. The records are compared with published pollen records in an attempt to discern if there are any trends of woodland clearance and abandonment from which changes in settlement patterns can be inferred. The results suggest that prolific metalworking industries correlate chronologically with expansive farming activity, which indicates that they were supported by a productive subsistence economy. Conversely, declines in metalwork production occur during periods when farming activity is generally less extensive and perhaps more centralised, and it is proposed that disparate socio-economic or –political factors, rather than a collapse of the subsistence economy, lies behind the demise of metalworking industries.
Resumo:
Bradykinin-related peptides (BRPs) represent one of the most widespread and closely studied families of amphibian defensive skin secretion peptides. Apart from canonical bradykinin (RPPGFSPFR) that was first reported in skin extracts of the European brown frog, Rana temporaria, many additional site-substituted, N- and/or C-terminally extended peptides have been isolated from skin extracts and secretions from representative species of the families Ranidae, Hylidae, Bombinatoridae and Leiopelmatidae. The most diverse range of BRPs has been found in ranid frog skin secretions and this probably reflects the diversity and number of species studied and their associated life histories within this taxon. Amolops (torrent or cascade frogs) is a genus within the Ranidae that has been poorly studied. Here we report the presence of two novel BRPs in the skin secretions of the Chinese Wuyi Mountain torrent frog (Amolops wuyiensis). Amolopkinins W1 and W2 are dodecapeptides differing in only one amino acid residue at position 2 (Val/Ala) that are essentially (Leu1, Thr6)-bradykinins extended at the N-terminus by either RVAL (W1) or RAAL (W2). Amolopkinins W1 and W2 are structurally similar to amolopkinin L1 from Amolops loloensis and the major BRP (Leu1, Thr6, Trp8)-bradykinin from the skin of the Japanese frog, Rana sakuraii. A. wuyiensis amolopkinins were separately encoded as single copies within discrete precursors of 61 amino acid residues as deduced from cloned skin cDNA. Synthetic replicates of both peptides were found to potently antagonize the contractile effects of canonical bradykinin on isolated rat ileum smooth muscle preparations. Amolopkinins thus appear to represent a novel sub-family of ranid frog skin secretion BRPs.
Resumo:
Social exclusion and social capital are widely used concepts with multiple and ambiguous definitions. Their meanings and indicators partially overlap, and thus they are sometimes used interchangeably to refer to the inter-relations of economy and society. Both ideas could benefit from further specification and differentiation. The causes of social exclusion and the consequences of social capital have received the fullest elaboration, to the relative neglect of the outcomes of social exclusion and the genesis of social capital. This article identifies the similarities and differences between social exclusion and social capital. We compare the intellectual histories and theoretical orientations of each term, their empirical manifestations and their place in public policy. The article then moves on to elucidate further each set of ideas. A central argument is that the conflation of these notions partly emerges from a shared theoretical tradition, but also from insufficient theorizing of the processes in which each phenomenon is implicated. A number of suggestions are made for sharpening their explanatory focus, in particular better differentiating between cause and consequence, contextualizing social relations and social networks, and subjecting the policy 'solutions' that follow from each perspective to critical scrutiny. Placing the two in dialogue is beneficial for the further development of each.