The need for psychiatric care in England: a spatial factor methodology

To ensure health resources are equitably distributed, composite indices of population morbidity or “health need” are often used. Measures of the dimensions of population morbidity (e.g. socioeconomic deprivation) relevant to health need are typically not directly available but indirectly measured through census or other sources. This paper considers measurement of latent population morbidity constructs using both health outcomes (e.g. hospital admissions, mortality) and observed area social and demographic indicators (e.g. census data). The constructs are allowed to be spatially correlated between areas, as well as correlated with one another within areas. The health outcomes may depend both on the latent constructs and on other relevant covariates (e.g. bed supply), with some covariates possibly measured only at higher (regional) scales. A case study considers variations in psychiatric admissions in 354 English local authority areas in relation to two latent constructs: area deprivation and social fragmentation.      

Dynamics of explosive volcanism at Unzen volcano: an experimental contribution

Knowledge of the dynamics of magma fragmentation is necessary for a better understanding of the explosive behaviour of silicic volcanoes. Here we have measured the fragmentation speed and the fragmentation threshold of five dacitic samples (6.7–53.5 vol% open porosity) from Unzen volcano, Kyushu, Japan. The measurements were carried out using a shock-tube-based fragmentation apparatus modified after Alidibirov and Dingwell (1996a,b). The results of the experimental work confirm the dominant influence of porosity on fragmentation dynamics. The velocity of the fragmentation front increases and the value of the fragmentation threshold decreases with increasing porosity. Further, we observe that the fragmentation speed is strongly influenced by the initial pressure difference and the texture of the dacite. At an initial pressure difference of 30 MPa, the fragmentation speed varies from 34 m/s for the least porous sample to 100 m/s for the most porous sample. These results are evaluated by applying them to the 1990–1995 eruptive activity of Unzen volcano. Emplacements of layered lava dome lobes, Merapi-type pyroclastic flows and minor explosive events dominated this eruption. The influence of the fragmentation dynamics on dome collapse and Vulcanian events is discussed.     

Paraguay's Atlantic Forest cover loss – Satellite-based change detection and fragmentation analysis between 2003 and 2013

The subtropical Atlantic Forest is a highly diverse ecosystem in South America and one of the most endangered rain forests in the world. The present study focuses specifically on the Paraguayan part of the tri-national Atlantic Forest. Over the last decades, the Paraguayan Atlantic Forest presented one of the highest deforestation rates in the world, and today, only a small share remains. Hence, forest loss in Paraguay's Atlantic Forest was detected and analysed through remote sensing and GIS methodologies based on Landsat images obtained in 2003 and 2013. The objective of this study was to examine the spatial impact of forest loss in Paraguay's Atlantic Forest over the past decade with a special focus on biodiversity conservation. Classifications results obtained overall accuracies above 83% and revealed that over 6000 km² of forest was cleared during the study period. The forest landscape and its fragmentation level were characterised through a set of landscape metrics, in particular the proximity analysis which support the identification of forest priority areas for nature conservation and potential biological corridors. In summary, the study revealed that deforestation and fragmentation of the Atlantic Forest area continued, but at a slower pace than that in the previous decade. Protected areas were conserved very effectively; however, forest core areas without any protection status require further attention. Intact forest patches and their connectivity are a crucial prerequisite to biodiversity conservation in a highly fragmented forest area. The combination of different remote sensing and GIS methods provides valuable information for sustainable forest management in the region.     

Probing the internal structure of the nuclei of comets

There is no direct evidence about the internal structure of cometary nuclei, which are mostly hidden by their gas and dust comae, and have not yet been orbited by any spacecraft. Their densities are low, typically of about 400 kg m⁻³ for 9P/Tempel 1 (that was impacted by the Deep Impact probe) and 67P/Churyumov-Gerasimenko (that is the target of the Rosetta mission). Such low densities are in favour of a high macro-porosity, or a high micro-porosity, or both. Observations of disruption or splitting of nuclei indeed suggest that some huge sub-nuclei or some meter-sized fragments could be the building blocks of comets. Analysis, from in-situ measurements and from remote light scattering observations, of the structure of the dust particles, which significantly consist of fluffy aggregates of submicron-sized grains, could be in favour of a fractal structure. However, the presence of huge icy grains in the innermost coma, and of flat layers on the surface of 9P/Tempel 1, are clues to the complexity of these objects, which have suffered drastic erosion phenomena on their elongated orbits. It is expected that the Rosetta mission will provide a fair understanding of the structure of the deep interior of the nucleus of 67P/Churyumov-Gerasimenko, thanks to the on-board CONSERT experiment.     

辽宁双台河口自然保护区景观破碎化研究

应用地理信息系统GIS生成辽宁双台河口自然保护区景观分类图,并结合Fragstas软件计算了5个景观破碎化指数,对保护区破碎化程度进行分析和评价。结果表明:保护区整体破碎化指数为0.271,廊道密度指数为0.2km/km2,保护区破碎化程度较低。景观破碎化的主要原因是人为活动的干扰,如石油的开采。随着石油的开采,廊道密度的增加,将使破碎化程度加深。廊道景观的发展是景观破碎化的前提和动因。     

How landscapes change: Integration of spatial patterns and human processes in temperate landscapes of southern Chile

A comprehensive understanding of the patterns that occur as human processes transform landscapes is necessary for sustainable development. We provide new evidence on how landscapes change by analysing the spatial patterns of human processes in three forest landscapes in southern Chile at different states of alteration (40%-90% of old-growth forest loss). Three phases of landscape alteration are distinguished. In Phase I (40%-65% of old-growth forest loss), deforestation rates are < 1% yr⁻¹, forests are increasingly degraded, and clearance for pastureland is concentrated on deeper soils. In Phase II (65%-80%), deforestation reaches its maximum rate of 1-1.5% yr⁻¹, with clearance for pastureland being the main human process, creating a landscape dominated by disturbed forest and shrubland. In this phase, clearance for pastureland is the primary driver of change, with pastures expanding onto poorer soils in more spatially aggregated patterns. In Phase III (80%-90%), deforestation rates are again relatively low (<1% yr⁻¹) and forest regrowth is observed on marginal lands. During this phase, clearance is the dominant process and pastureland is the main land cover. As a forest landscape is transformed, the extent and intensity of human processes vary according to the existing state of landscape alteration, resulting in distinctive landscape patterns in each phase. A relationship between spatial patterns of land cover and human-related processes has been identified along the gradient of landscape alteration. This integrative framework can potentially provide insights into the patterns and processes of dynamic landscapes in other areas subjected to intensifying human use.     

On size and boundary effects in scaled model blasts—fractures and fragmentation patterns

This contribution is the third part of a paper addressing size and boundary effects on explosively induced wave propagation, fracturing and fracture pattern development in small scale laboratory specimens, which are frequently used for model blast tests. Small cylindrical and block type specimens fabricated from concrete, sandstone and amphibolite are centre-line loaded by linear explosive charges and supersonically detonated. Using shock wave theory, elastic wave propagation theory, and fracture mechanics it is shown that the type of boundary conditions prescribed at the outer boundary of the cylinder controls the extension of stem cracking and the development of the fragmentation pattern within the body of the cylinder and the cube specimens. In the case of a composite specimen, where a cylindrical core of different material is embedded in a cylinder or in a cube, the level of fracturing and fragmentation is controlled by the conditions and possible de-lamination of the interface which, in turn, depends on the relative dimensions of the core and the block. Using known results from the theory of wave interaction with free boundaries and interfaces it will be shown that the fracture strain and the notch sensitivity of the material expressed by imperfections play an important role. Equally important is the ratio between the length of the pulse (space-wise or time-wise) and the characteristic dimensions of the models. Axi-radial boundary cracks and spalling will be explained on the basis of earlier wave propagation studies associated with supersonic blasting. Theoretical results are in good agreement with numerical simulations and recent experimental findings.     

市场分割对我国区域间技术扩散的影响

采用随机前沿分析方法和边界效应方法,分别度量了我国在1987～2008年间东、中、西部地区的前沿技术进步和全国平均的市场分割程度;采用非线性EGLS方法,考察了市场分割对我国区域技术扩散的影响。结果表明:市场分割对东部地区向中、西部地区的技术扩散具有明显的妨碍作用,导致了无谓的效率损失,该项损失在2004年以后约为12%左右。     

Design of a model blasting system to measure peak p-wave stress

Literature review information and model scale rock blasting tests have been utilized to study the effects of some blast and fragmentation parameters on peak p-wave stress. A method for modelling scaled blasting in sandstone blocks with dimensions 515×335×215 mm³ has been presented. The dynamic and static properties of the sandstone are given. The results from model blasting experiments instrumented with pressure gauges are discussed. It is also shown there exists a useful correlation between blast, fragmentation parameters and peak p-wave stress.