Protostellar Jet and Outflow in the Collapsing Cloud Core

We investigate the driving mechanism of outflows and jets in star formation process using resistive MHD nested grid simulations. We found two distinct flows in the collapsing cloud core: Low-velocity outflows (sim 5 km/s) with a wide opening angle, driven from the first adiabatic core, and high-velocity jets (sim 50 km/s) with good collimation, driven from the protostar. High-velocity jets are enclosed by low-velocity outflow. The difference in the degree of collimation between the two flows is caused by the strength of the magnetic field and configuration of the magnetic field lines. The magnetic field around an adiabatic core is strong and has an hourglass configuration. Therefore, the low-velocity outflow from the adiabatic core are driven mainly by the magnetocentrifugal mechanism and guided by the hourglass-like field lines. In contrast, the magnetic field around the protostar is weak and has a straight configuration owing to Ohmic dissipation in the high-density gas region. Therefore, high-velocity jet from the protostar are driven mainly by the magnetic pressure gradient force and guided by straight field lines. Differing depth of the gravitational potential between the adiabatic core and the protostar cause the difference of the flow speed. Low-velocity outflows correspond to the observed molecular outflows, while high-velocity jets correspond to the observed optical jets. We suggest that the protostellar outflow and the jet are driven by different cores (the first adiabatic core and protostar), rather than that the outflow being entrained by the jet.Comment: To appear in the proceedings of the "Protostellar Jets in Context" conference held on the island of Rhodes, Greece (7-12 July 2008

Towards an archaeology of media ecologies : the case of Italian free radios

This article looks at the contemporary reinvention of the term Media Ecologies in the work of Matthew Fuller, arguing that its provenance is less form Postman's Media Ecology Association andmore form the work of Felix Guattari. It then presents an account of free radios in Italy and France in the 1970s and contemporary pirate radio as exemplary cases of media ecologies in Fuller's sense of the term

Aetiology of sudden cardiac death in sport: a histopathologist's perspective.

In the UK, when a young person dies suddenly, the coroner is responsible for establishing the cause of death. They will ask a consultant pathologist to carry out an autopsy in order to ascertain when, where and how that person died. Once the cause of death is established and is due to natural causes, the coroner can issue a death certificate. Importantly, the coroner is not particularly interested in the cause of death as long as it is due to natural causes, which avoids the need for an inquest (a public hearing about the death). However, if no identifiable cause is established at the initial autopsy, the coroner can refer the heart to a cardiac pathologist, since the cause of death is usually due to heart disease in most cases. Consultant histopathologists are responsible for the analysis of human tissue from both living individuals and the dead in order to make a diagnosis of disease. With recent advancements in the management protocols for routine autopsy practice and assessment following the sudden death of a young individual, this review describes the role of the consultant histopathologist in the event of a sudden death of a young athletic individual, together with the older middle-aged 'weekend warrior' athlete. It provides concise mechanisms for the main causes of sudden cardiac death (including coronary artery disease, cardiomyopathies, valve abnormalities, major vessel ruptures and electrical conduction abnormalities) based on detailed autopsy data from our specialised cardiac pathology laboratory. Finally, the review will discuss the role of the histopathologist in the event of a 'negative' autopsy

The influence of organizational culture on the outcome of an IS implementation

A number of information system (IS) studies have adopted organizational culture (OC) theory to investigate IS implementations. The studies highlight that members will reach consensus or agreement in the use of an IS but also experience inevitable tensions and ambiguities in the use of the IS. However, literature related to IS implementation/OC has rarely examined the influence that the saliency of specific cultural practices may have on the success or failure of IS implementations. Using a case study approach, we adopted the “soft positivism” research philosophy to collect data, underpinned by Martin’s (1992) integration and differentiation perspectives of OC to study organizational implementation of an IS. These perspectives served as interpretive lenses through which to explain how members’ salient behaviors towards an IS evolved during the implementation process. Our study augments the IS implementation/OC literature by demonstrating how salient cultural practices influence the outcome of IS implementatio

Achieving IT diffusion within the fragments: an IT culture perspective

Many organizations still fail to make a return from the huge investments they make in implementing complex Information Technology (IT). This is usually due to cultural forces that inhibit the level of usage required to facilitate IT Diffusion. An emerging stream of research highlights the IT culture perspective, a perspective vital for understanding individuals’ social practices when they interact with IT. This paper adopted a case study approach to explore how the IT culture perspective may explain how organizational diffusion of an IT may happen despite opposing cultural forces causing a stalemate to the diffusion process. This study identified three IT culture archetypes - embracing, rejecting and confused, depicting a fragmented IT culture during the adaption, acceptance and routinization stages of diffusion of an IT. This study highlights how a salient element of a fragmented IT culture-embracing IT culture archetype could explain how diffusion of an IT happened despite the manifestations of negative IT culture archetypes - ‘confused’ and ‘rejecting’ during the diffusion process

Designing a novel virtual collaborative environment to support collaboration in design review meetings

Project review meetings are part of the project management process and are organised to assess progress and resolve any design conflicts to avoid delays in construction. One of the key challenges during a project review meeting is to bring the stakeholders together and use this time effectively to address design issues as quickly as possible. At present, current technology solutions based on BIM or CAD are information-centric and do not allow project teams to collectively explore the design from a range of perspectives and brainstorm ideas when design conflicts are encountered. This paper presents a system architecture that can be used to support multi-functional team collaboration more effectively during such design review meetings. The proposed architecture illustrates how information-centric BIM or CAD systems can be made human- and team-centric to enhance team communication and problem solving. An implementation of the proposed system architecture has been tested for its utility, likability and usefulness during design review meetings. The evaluation results suggest that the collaboration platform has the potential to enhance collaboration among multi-functional teams

On the road to personalised and precision geomedicine: medical geology and a renewed call for interdisciplinarity

Our health depends on where we currently live, as well as on where we have lived in the past and for how long in each place. An individual’s place history is particularly relevant in conditions with long latency between exposures and clinical manifestations, as is the case in many types of cancer and chronic conditions. A patient’s geographic history should routinely be considered by physicians when diagnosing and treating individual patients. It can provide useful contextual environmental information (and the corresponding health risks) about the patient, and should thus form an essential part of every electronic patient/health record. Medical geology investigations, in their attempt to document the complex relationships between the environment and human health, typically involve a multitude of disciplines and expertise. Arguably, the spatial component is the one factor that ties in all these disciplines together in medical geology studies. In a general sense, epidemiology, statistical genetics, geoscience, geomedical engineering and public and environmental health informatics tend to study data in terms of populations, whereas medicine (including personalised and precision geomedicine, and lifestyle medicine), genetics, genomics, toxicology and biomedical/health informatics more likely work on individuals or some individual mechanism describing disease. This article introduces with examples the core concepts of medical geology and geomedicine. The ultimate goals of prediction, prevention and personalised treatment in the case of geology-dependent disease can only be realised through an intensive multiple-disciplinary approach, where the various relevant disciplines collaborate together and complement each other in additive (multidisciplinary), interactive (interdisciplinary) and holistic (transdisciplinary and cross-disciplinary) manners

Smoking and tooth discolouration: findings from a national cross-sectional study

Background: Smoking is a risk factor of a number of oral diseases; the extent to which tobacco products influence dental aesthetics has not been widely investigated. The aim of this study was to determine satisfaction with own tooth colour of smokers and non-smokers and to investigate whether smokers have higher levels of self-assessed tooth discolouration compared to nonsmokersMethods: A cross sectional national study was conducted on sample of 6,000 UK adults. A total of 3,384 adults was interviewed. Smoking behaviour was recorded together with satisfaction with own tooth colour. Prevalence of perceived discolouration was measured by asking respondents to match their own tooth colour to one of a set of seven photographs of differing severities of discolouration.Results: Twenty eight percent of smokers reported having moderate and severe levels of tooth discolouration compared to 15% in non-smokers. As well as more often perceiving discolouration smokers were also more likely to be dissatisfied with their own tooth colour compared to nonsmokers.Conclusion: The study provides further evidence of the negative impact of tobacco smoking on dental aesthetics in the general public. The evidence provided by the study may be of value in short interventions for smoking cessation in the dental setting

Neologistic jargon aphasia and agraphia in primary progressive aphasia

The terms 'jargon aphasia' and 'jargon agraphia' describe the production of incomprehensible language containing frequent phonological, semantic or neologistic errors in speech and writing, respectively. Here we describe two patients with primary progressive aphasia (PPA) who produced neologistic jargon either in speech or writing. We suggest that involvement of the posterior superior temporal-inferior parietal region may lead to a disconnection between stored lexical representations and language output pathways leading to aberrant activation of phonemes in neologistic jargon. Parietal lobe involvement is relatively unusual in PPA, perhaps accounting for the comparative rarity of jargon early in the course of these diseases. (C) 2008 Elsevier B.V. All rights reserved

Stress Analysis of Prithvi Missil Wing Subjected to Aerodynamic Forces

The stress problem of Prithvi missile wing is investigated . The analysis is carried out by the finite element method by using the ASKA software package. Finite element analysis is carried out for pressure loading, and thermal loading arising from aerodynamic heating . The,analysis for pressure loading indicates that there is stress concentration at the wing root region results obtained for various cases of this loading are presented and discussed. The distortion of the wing produced by aerodynamic heating has also been displayed