20 resultados para organ and inter-specific patterns
em Aston University Research Archive
Resumo:
Both animal and human studies suggest that the efficiency with which we are able to grasp objects is attributable to a repertoire of motor signals derived directly from vision. This is in general agreement with the long-held belief that the automatic generation of motor signals by the perception of objects is based on the actions they afford. In this study, we used magnetoencephalography (MEG) to determine the spatial distribution and temporal dynamics of brain regions activated during passive viewing of object and non-object targets that varied in the extent to which they afforded a grasping action. Synthetic Aperture Magnetometry (SAM) was used to localize task-related oscillatory power changes within specific frequency bands, and the time course of activity within given regions-of-interest was determined by calculating time-frequency plots using a Morlet wavelet transform. Both single subject and group-averaged data on the spatial distribution of brain activity are presented. We show that: (i) significant reductions in 10-25 Hz activity within extrastriate cortex, occipito-temporal cortex, sensori-motor cortex and cerebellum were evident with passive viewing of both objects and non-objects; and (ii) reductions in oscillatory activity within the posterior part of the superior parietal cortex (area Ba7) were only evident with the perception of objects. Assuming that focal reductions in low-frequency oscillations (< 30 Hz) reflect areas of heightened neural activity, we conclude that: (i) activity within a network of brain areas, including the sensori-motor cortex, is not critically dependent on stimulus type and may reflect general changes in visual attention; and (ii) the posterior part of the superior parietal cortex, area Ba7, is activated preferentially by objects and may play a role in computations related to grasping. © 2006 Elsevier Inc. All rights reserved.
Resumo:
Patients with Bipolar Disorder (BD) perform poorly on tasks of selective attention and inhibitory control. Although similar behavioural deficits have been noted in their relatives, it is yet unclear whether they reflect dysfunction in the same neural circuits. We used functional magnetic resonance imaging and the Stroop Colour Word Task to compare task related neural activity between 39 euthymic BD patients, 39 of their first-degree relatives (25 with no Axis I disorders and 14 with Major Depressive Disorder) and 48 healthy controls. Compared to controls, all individuals with familial predisposition to BD, irrespective of diagnosis, showed similar reductions in neural responsiveness in regions involved in selective attention within the posterior and inferior parietal lobules. In contrast, hypoactivation within fronto-striatal regions, implicated in inhibitory control, was observed only in BD patients and MDD relatives. Although striatal deficits were comparable between BD patients and their MDD relatives, right ventrolateral prefrontal dysfunction was uniquely associated with BD. Our findings suggest that while reduced parietal engagement relates to genetic risk, fronto-striatal dysfunction reflects processes underpinning disease expression for mood disorders. © 2011 Elsevier Inc.
Resumo:
How speech is separated perceptually from other speech remains poorly understood. Recent research indicates that the ability of an extraneous formant to impair intelligibility depends on the variation of its frequency contour. This study explored the effects of manipulating the depth and pattern of that variation. Three formants (F1+F2+F3) constituting synthetic analogues of natural sentences were distributed across the 2 ears, together with a competitor for F2 (F2C) that listeners must reject to optimize recognition (left = F1+F2C; right = F2+F3). The frequency contours of F1 − F3 were each scaled to 50% of their natural depth, with little effect on intelligibility. Competitors were created either by inverting the frequency contour of F2 about its geometric mean (a plausibly speech-like pattern) or using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Adding a competitor typically reduced intelligibility; this reduction depended on the depth of F2C variation, being greatest for 100%-depth, intermediate for 50%-depth, and least for 0%-depth (constant) F2Cs. This suggests that competitor impact depends on overall depth of frequency variation, not depth relative to that for the target formants. The absence of tuning (i.e., no minimum in intelligibility for the 50% case) suggests that the ability to reject an extraneous formant does not depend on similarity in the depth of formant-frequency variation. Furthermore, triangle-wave competitors were as effective as their more speech-like counterparts, suggesting that the selection of formants from the ensemble also does not depend on speech-specific constraints.
Resumo:
How speech is separated perceptually from other speech remains poorly understood. Recent research indicates that the ability of an extraneous formant to impair intelligibility depends on the variation of its frequency contour. This study explored the effects of manipulating the depth and pattern of that variation. Three formants (F1+F2+F3) constituting synthetic analogues of natural sentences were distributed across the 2 ears, together with a competitor for F2 (F2C) that listeners must reject to optimize recognition (left = F1+F2C; right = F2+F3). The frequency contours of F1 - F3 were each scaled to 50% of their natural depth, with little effect on intelligibility. Competitors were created either by inverting the frequency contour of F2 about its geometric mean (a plausibly speech-like pattern) or using a regular and arbitrary frequency contour (triangle wave, not plausibly speech-like) matched to the average rate and depth of variation for the inverted F2C. Adding a competitor typically reduced intelligibility; this reduction depended on the depth of F2C variation, being greatest for 100%-depth, intermediate for 50%-depth, and least for 0%-depth (constant) F2Cs. This suggests that competitor impact depends on overall depth of frequency variation, not depth relative to that for the target formants. The absence of tuning (i.e., no minimum in intelligibility for the 50% case) suggests that the ability to reject an extraneous formant does not depend on similarity in the depth of formant-frequency variation. Furthermore, triangle-wave competitors were as effective as their more speech-like counterparts, suggesting that the selection of formants from the ensemble also does not depend on speech-specific constraints. © 2014 The Author(s).
Resumo:
This paper seeks to understand North Korea’s Kim Il Sung to Kim Jong Il and Kim Jong Il to Kim Jong Un’s hereditary transition by proposing a comparative analysis of several dictatorship families. The paper utilizes totalitarian successions in Nicaragua with García and Debayle, in Haiti with the Duvalier family, in Syria with the al-Assads, in Azerbaijan with the Aliyevs, in Congo with the Kabilas in order to draw parallels and difference with the North Korea. Eventually, North Korea’s control over information and its management of myths are highlighted as factors that have enabled the country’s hereditary transition, though new patterns of domestic governance might lead to a different political environment over the Korean peninsula.
Resumo:
This paper explores the dynamics of inter-sectoral technological integration by introducing the concept of bridging platform as a node of pervasive technologies, whose collective broad applicability may enhance the connection between ‘distant’ knowledge by offering a technological coupling. Using data on patents obtained from the CRIOS-PATSTAT database for four EU countries (Germany, UK, France and Italy), we provide empirical evidence that bridging platforms are likely to connect more effectively innovations across distant technological domains, fostering inter-sectoral technological integration and the development of original innovation. Public research organisations are also found to play a crucial role in terms of technological integration and original innovation due to their higher capacity to access and use bridging platforms within their innovation activities.
Resumo:
This paper evaluates the extent of inter-industry and inter-regional wage spillovers across the UK. An extensive body of literature exists suggesting that wages elsewhere affect wage determination and levels of satisfaction, but this paper extends the analysis of wage determination to examine the effects of inward investment in the process. Thus far the specific effect of foreign wages on domestic wage determination has not been evaluated. We employ industry- and regional-level panel data for the UK, and contrast results from alternative approaches to space-time modelling. Each supports the notion that such wage spillovers do occur, though assumptions made concerning the modelling of spatial interaction are important. Further, such wage spillovers are more widespread for skilled than for unskilled workers and also lower in areas of high unemployment. © 2006 Regional Studies Association.
Resumo:
EV is a child with a talent for learning language combined with Asperger syndrome. EV’s talent is evident in the unusual circumstances of her acquisition of both her first (Bulgarian) and second (German) languages and the unique patterns of both receptive and expressive language (in both the L1 and L2), in which she shows subtle dissociations in competence and performance consistent with an uneven cognitive profile of skills and abilities. We argue that this case provides support for theories of language learning and usage that require more general underlying cognitive mechanisms and skills. One such account, the Weak Central Coherence (WCC) hypothesis of autism, provides a plausible framework for the interpretation of the simultaneous co-occurrence of EV’s particular pattern of cognitive strengths and weaknesses. Furthermore, we show that specific features of the uneven cognitive profile of Asperger syndrome can help explain the observed language talent displayed by EV. Thus, rather than demonstrating a case where language learning takes place despite the presence of deficits, EV’s case illustrates how a pattern of strengths within this profile can specifically promote language learning.
Resumo:
The revival of terracotta and faience in British architecture was widespread, dramatic in its results and, for two decades, the subject of intense debate. However the materials have been frequently denigrated and more generally disregarded by both architects and historians. This study sets out to record and explain the rise and fall of interest in terracotta and faience, the extent and nature of the industry and the range of architectural usage in the Victorian, Edwardian and inter-war periods. The first two chapters record the faltering use of terracotta as an 'artificial stone', until the material gained its own identity, largely through the appreciation of Italian architecture. In the mid-Victorian period, terracotta will be seen to have become symbolic of the philosophy of the Victoria and Albert Museum and its Art School in attempting to reform both architecture and the decorative arts. The adoption of terracotta was furthered as much by industrial as aesthetic factors; three chapters examine how the exploitation of coal-measure clays, developments in the processes of manufacture, the changing motivation of industrialists and differing economics of production served to promote and then to hinder expansion and adaptation. The practical values of economy, durability and fire-resistance and the aesthetic potential, seen in terms of colour and decorative and sculptural modelling, became inter-related in the work of the architects who made extensive use of architectural ceramics. A correlation emerges between the free Gothic style, exemplified by the designs of Alfred Waterhouse and the use of red terracotta supplied from Ruabon, and between the eclectic Renaissance style and a buff material produced by different manufacturers.These patterns were modified as a result of the adoption of faience for facing external walls as well as interiors, and because of the new architectural requirements and tastes of the twentieth century. The general timidity in exploiting the scope for polychromatic decoration and the increasing opposition to architectural ceramics is contrasted with the most successful schemes produced for cinemas, chain-stores and factories. In the last chapter, those undertaken by the Hathern Station Brick and Terracotta Company between 1896 and 1939 are used as a case study; they confirm that manufacturers, architects and clients were all committed to creating a modern and yet decorative architecture, appropriate for new building types and that would appeal to and be comprehensible to the public.
Resumo:
The enterprise management (EM) approach provides a holistic view of organizations and their related information systems. In order to align information technology (IT) innovation with global markets and volatile virtualization, traditional firms are seeking to reconstruct their enterprise structures alongside repositioning strategy and establish new information system (IS) architectures to transform from single autonomous entities into more open enterprises supported by new Enterprise Resource Planning (ERP) systems. This chapter shows how ERP engage-abilities cater to three distinctive EM patterns and resultant strategies. The purpose is to examine the presumptions and importance of combing ERP and inter-firm relations relying on the virtual value chain concept. From a review of the literature on ERP development and enterprise strategy, exploratory inductive research studies in Zoomlion and Lanye have been conducted. In addition, the authors propose a dynamic conceptual framework to demonstrate the adoption and governance of ERP in the three enterprise management forms and points to a new architectural type (ERPIII) for operating in the virtual enterprise paradigm. © 2012, IGI Global.
Resumo:
This paper considers the use of general performance measures in evaluating specific planning and design decisions in higher education and reflects on the students' learning process. Specifically, it concerns the use of the MENTOR multimedia computer aided learning package for helping students learn about OR as part of a general business degree. It includes the transfer of responsibility for a learning module to a new staff member and a change from a single tutor to a system involving multiple tutors. Student satisfaction measures, learning outcome measures and MENTOR usage patterns are examined in monitoring the effects of the changes in course delivery. The results raise some questions about the effectiveness of general performance measures in supporting specific decisions relating to course design and planning.
Resumo:
Suboptimal maternal nutrition during gestation results in the establishment of long-term phenotypic changes and an increased disease risk in the offspring. To elucidate how such environmental sensitivity results in physiological outcomes, the molecular characterisation of these offspring has become the focus of many studies. However, the likely modification of key cellular processes such as metabolism in response to maternal undernutrition raises the question of whether the genes typically used as reference constants in gene expression studies are suitable controls. Using a mouse model of maternal protein undernutrition, we have investigated the stability of seven commonly used reference genes (18s, Hprt1, Pgk1, Ppib, Sdha, Tbp and Tuba1) in a variety of offspring tissues including liver, kidney, heart, retro-peritoneal and inter-scapular fat, extra-embryonic placenta and yolk sac, as well as in the preimplantation blastocyst and blastocyst-derived embryonic stem cells. We find that although the selected reference genes are all highly stable within this system, they show tissue, treatment and sex-specific variation. Furthermore, software-based selection approaches rank reference genes differently and do not always identify genes which differ between conditions. Therefore, we recommend that reference gene selection for gene expression studies should be thoroughly validated for each tissue of interest. © 2011 Elsevier Inc.
Resumo:
This research takes a dynamic view on the knowledge coordination process, aiming to explain how the process is affected by changes in the operating environment, from normal situations to emergencies in traditional and fast-response organizations, and why these changes occur. We first conceptualize the knowledge coordination process by distinguishing between four dimensions - what, when, how and who - that together capture the full scope of the knowledge coordination process. We use these dimensions to analyze knowledge coordination practices and the activities constituting these practices, in the IT functions of traditional and fast-response (military) organizations where we distinguish between "normal" and "emergency" operating conditions. Our findings indicate that (i) inter-relationships between knowledge coordination practices change under different operating conditions, and (ii) the patterns of change are different in traditional and fast-response organizations.