Application of computer graphics to mine surveying and planning

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Testing continuum models of psychosis: No reduction in source monitoring ability in healthy individuals prone to auditory hallucinations

People with schizophrenia who hallucinate show impairments in reality monitoring (the ability to distinguish internally generated information from information obtained from external sources) compared to non-hallucinating patients and healthy individuals. While this may be explained at least in part by an increased externalizing bias, it remains unclear whether this impairment is specific to reality monitoring, or whether it also reflects a general deficit in the monitoring of self-generated information (internal source monitoring). Much interest has focused recently on continuum models of psychosis which argue that hallucination-proneness is distributed in clinical and non-clinical groups, but few studies have directly investigated reality monitoring and internal source monitoring abilities in healthy individuals with a proneness to hallucinations. Two experiments are presented here: the first (N = 47, with participants selected for hallucination-proneness from a larger sample of 677 adults) found no evidence of an impairment or externalizing bias on a reality monitoring task in hallucination-prone individuals; the second (N = 124) found no evidence of atypical performance on an internal source monitoring task in hallucination-prone individuals. The significance of these findings is reviewed in light of the clinical evidence and the implications for models of hallucination generation discussed

Expression of ciliary neurotrophic factor and the neurotrophins - Nerve and growth factor, brain-derived neurotrophic factor and neurotrophin 3 - in cultured rat hippocampal astrocytes

Cultured astrocytes are known to possess a range of neurotrophic activities in culture. In order to examine which factors may be responsible for these activities, we have examined the expression of the genes for four known neurotrophic factors - ciliary neurotrophic factor (CNTF), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) - in purified astrocyte cultures derived from neonatal rat hippocampus. Hippocampal astrocytes were found to expresssd mRNA for three neurotrophic factors - CNTF, NGF and NT3 - at significantly higher levels than other cultured cell types or cell lines examined. BDNF messenger RNA (mRNA), however, was undetectable in these astrocytes. The levels of CNTF, NGF and NT3 mRNA in astrocytes were largely unaffected by their degree of confluency, while serum removal caused only a transient decrease in mRNA levels, which returned to basal levels within 48 h. Astrocyte-derived CNTF was found to comigrate with recombinant rat CNTF at 23 kD on a Western blot. Immunocytochemical analysis revealed strong CNTF immunoreactivity in the cytoplasm of astrocytes, weak staining in the nucleus, but no CNTF at the cell surface. NGF and NT3 were undetectable immunocytochemically. CNTF-like activity, as assessed by bioassay on ciliary ganglion neurons, was found in the extract of cultured astrocytes but not in conditioned medium, whereas astrocyte-conditioned medium supported survival of dorsal root ganglion neurons but not ciliary or nodose ganglion neurons. This conditioned medium activity was neutralized with antibodies to NGF. Astrocyte extract also supported survival of dorsal root ganglion and nodose ganglion neurons, but these activities were not blocked by anti-NGF. Part, but not all, of the activity in astrocyte extracts which sustained nodose ganglion neurons could be attributed to CNTF

Resource Advantage Theory and Fair Trade Social Enterprises

This paper will investigate the competitive position of both fair trade (FT) social enterprises Divine Chocolate Ltd (Divine) and Cafédirect in their respective UK markets, namely chocolate confectionery and hot beverages. Using Eisenhardt’s (1989, 1991, and 2007) approach to building theory from multiple case studies, this four-year PhD study aims to identify the resources that enable FT social enterprises to compete. This research draws on recent developments in competition theory such as resource advantage theory (R-A theory), termed a general theory of competition. The paper will critically analyse if the social and ethical elements of these firm’s product offerings really constitute meaningful differentiators (i.e. comparative advantage) as required by R-A theory (Hunt and Morgan 1995, Hunt 2001). Hunt and Derozier (2004) argue that R-A theory can ground theories of business and marketing strategy and therefore identifying the competitive resources of FT social enterprises will have important strategic implications. The research findings show that both Divine and Cafédirect have established a mainstream competitive position in specific product segments and distribution channels. Thus illustrating intra-industry demand to be heterogeneous. In addition, both companies have been a catalyst for change by influencing the strategies and policies of both branded manufactures and retailers such as Cooperative Food (CF). The key theoretical contribution validates ‘social resources’ and its three inter-related components: ethical and social commitments, connections with partners and consistency of behaviour as a resource to extend R-A theory. These ‘social resources’ in combination with both relational resources and threshold capabilities (e.g. product quality) result in a competitive position for both case organisations. The ethical and social commitments of ‘social resources’ also appears to provide an example of an ethical underpinning to Relationship Marketing. The identification of ‘social resources’ has important wider implications for both other social enterprises and those companies who are aiming to achieve a competitive position based on social commitments

Elasticity of anti-tetrachiral anisotropic lattices

AbstractThis work describes the theoretical, numerical and experimental in-plane and out-of-plane elastic behavior of a class of anti-tetrachiral lattice structures with in-plane negative Poisson’s ratios and anisotropic behavior. Closed form analytical solutions related to the uniaxial stiffness, in-plane Poisson’s ratio and bounds for the transverse shear modulus are derived, and compared against homogenization-based finite element methods and experimental tests performed on rapid prototyping-made samples. The benchmarked models are then used to investigate the behaviors of the anisotropic negative Poisson’s ratio structures against the geometry parameters defining the unit cell. The results show the existence of large variations in linear elastic constants and degree of anisotropy, which can be achieved by changing the lattice geometry parameters. The analysis presented in this work provides meaningful guidance to assist design anti-tetrachiral anisotropic lattices, which could serve as sandwich panel cores in aerospace applications