1,199 research outputs found

    Life without water

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    Anhydrobiosis, or life without water is commonly demonstrated by a number of plants and animals. These organisms have the capacity to loose all body water, remain dry for various periods, and then be revived by rehydration. While in the anhydrobiotic state, these organisms become highly resistant to several environmental stresses such as extremely low temperatures, elevated temperatures, ionizing radiation, and high vacuum. Since water is commonly thought to be essential for life, survival of anhydrobiotic organisms with an almost total loss of water is examined. A search of literature reveal that many anhydrobiotic organisms make large quantities of trehalose or other carbohydrates. Laboratory experiments have shown that trehalose is able to stabilize and preserve microsomes of sarcoplasmic reticulum and artificial liposomes. It was demonstrated that trehalose and other disaccharides can interact directly with phosopipid headgroups and maintain membranes in their native configuration by replacing water in the headgroup region. Recent studies show that trehalose is an effective stabilizer of proteins during drying and that it does so by direct interaction with groups on the protein. If life that is able to withstand environmental extremes has ever developed on Mars, it is expected that such life would have developed some protective compounds which can stabilize macromolecular structure in the absence of water and at cold temperatures. On Earth, that role appears to be filled by carbohydrates that can stabilize both membrane and protein stuctures during freezing and drying. By analog with terrestrial systems, such life forms might develop resistance either during some reproductive stage or at any time during adult existence. If the resistant form is a developmental stage, the life cycle of the organism must be completed with a reasonable time period relative to time when environmental conditions are favorable. This would suggest that simple organisms with a short life cycle might be most sucessful

    Mechanisms of heat transport through the floor of the equatorial Pacific Ocean

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    Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 1981The equatorial Pacific heat flow low, a major oceanic geothermal anomaly centered on the equatorial sediment bulge, was investigated using deeply penetrating heat flow probes (6-11 meters penetration) within three detailed surveys (400 km2) and along over 10,000 km of continuous seismic profiles (CSP). Previous heat flow measurements in this region defined a broad region characterized by a heat flux well below 1 HFU. We report 98 new measurements collected during cruises PLEIADES 3 and KNORR 73-4 that verify the anomalous nature of the heat flux and also define non-linear temperature gradients (concave down). Temperature field disturbances due to perturbations of a purely conductive heat transport regime are incapable of suitably explaining either of these observations . A simple model incorporating heat transport by both conduction and fluid convection through the sediments fits the observations. A volume flux of (hydrothermal) fluid in the range of 10-6 to 10-5 cm3/sec/cm2 (0.1 liter/yr/cm2) is required. The sense of the flow for all measurements exhibiting non-linear gradients is upward out of the sediment column; no evidence for the recharging of the system was observed. Investigation of a well-defined boundary of the low zone at 4°N and 114°W showed a transition from low and variable heat flow to values compatible with thermal models that correlated with a change in the nature of the basement from rough to smooth. A few outcrops occur in the area of rough basement, but otherwise the region is well-sedimented (greater than 200 meters). Measurements within a detailed survey centered at this transition showed a dramatic increase in heat flow from 1.21 HFU to values greater than 3 HFU over a horizontal distance of 10km. A similar transition from non-linear to linear temperature gradients was not observed as nearly every measurement was non-linear. Heat flow measurements located in well-sedimented, outcrop-free areas (A environments) were associated with linear gradients and a heat flux greater than 1 HFU, however, several of these values were well below the theoretical heat flow for the appropriate age crust. Values measured in environments other than A exhibited variable heat flow and non-linear gradients. The average value of measurements located in A environments within the equatorial Pacific heat flow low was 1.37±0.27 HFU. The previously reported average was 0.92±0.48 HFU based on several measurements from L-DGO cruise VEMA 24-3. The average heat flow measured at a survey located outside the low heat flow zone on crust of 55 ±5 m.a. was 1.76 ±0.30 HFU which is in good agreement with the theoretical value of 1.60. The measurements in this survey were not located in A environments suggesting that crustal convection has ceased or is greatly attenuated within crust of this age. Error analysis of the geothermal data reduction using the convective/conductive heat transport model suggests that the volume flux parameter is sensitive to temperature measurement errors greater than a few millidegrees. Volume fluxes less than 10-7 cm/sec are difficult to distinguish from the purely conductive case assuming instrumental accuracies of 0.001°C. Resolution of the volume flux deteriorates as heat flow decreases and is poor for values less than 0.5 HFU. A detailed survey located within the low zone confirmed previous measurements of low heat flow, however, due to the low value of heat flow (about 0.5 HFU) the small-scale variability could not be clearly defined

    An Integrated Retail Supply Chain Risk Management Framework: A System Thinking Approach

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    It is often taken for granted that the right products will be available to buy in retail outlets seven days a week, 52 weeks a year. Consumer perception is that of a simple service requirement, but the reality is a complex, time sensitive system - the retail supply chain (RSC). Due to short product life-cycles with uncertain supply and demand behaviour, the RSC faces many challenges and is very vulnerable to disruptions. In addition, external risk events such as BREXIT, extreme weather, the financial crisis, and terror attacks mean there is a need for effective RSC risk management (RSCRM) processes within organisations. Literature shows that although there is an increasing amount of research in RSCRM, it is highly theoretical with limited empirical evidence or applied methodologies. With an active enthusiasm coming from industry practitioners for RSCRM methodologies and support solutions, the RSCRM research community have acknowledged that the main issue for future research is not tools and techniques, but collaborative RSC system wide implementation. The implementation of a cross-organisational initiative such as RSCRM is a very complex task that requires real-world frameworks for real-world practitioners. Therefore, this research study attempts to explore the business requirements for developing a three-stage integrated RSCRM framework that will encourage extended RSC collaboration. While focusing on the practitioner requirements of RSCRM projects and inspired by the laws of Thermodynamics and the philosophy of System Thinking, in stage one a conceptual reference model, The �6 Coefficient, was developed building on the formative work of supply chain excellence and business process management. The �6 Coefficient reference model has been intricately designed to bridge the theoretical gap between practitioner and researcher with the aim of ensuring practitioner confidence in partaking in a complex business process project. Stage two focused on a need for a standardised vocabulary, and through the SCOR11 reference guide, acts as a calibration point for the integrated framework, ensuring easy transfer and application within supply chain industries. In their design, stages one and two are perfect complements to the final stage of the integrated framework, a risk assessment toolbox based on a Hybrid Simulation Study capable of monitoring the disruptive behaviour of a multi-echelon RSC from both a macro and micro level using the techniques of System Dynamics (SD) and Discrete Event Simulation (DES) modelling respectively. Empirically validated through an embedded mixed methods case study, results of the integrated framework application are very encouraging. The first phase, the secondary exploratory study, gained valuable empirical evidence of the barriers to successfully implementing a complex business project and also validated using simulation as an effective risk assessment tool. Results showed certain high-risk order policy decisions could potentially reduce total costs (TC) by over 55% and reduce delivery times by 3 days. The use of the �6 Coefficient as the communication/consultation phase of the primary RSCRM case study was hugely influential on the success of the overall hybrid simulation study development and application, with significant increase in both practitioner and researcher confidence in running an RSCRM project. This was evident in the results of the hybrid model’s macro and micro assessment of the RSC. SD results effectively monitored the behaviour of the RSC under important disruptive risks, showing delayed effects to promotions and knowledge loss resulted in a bullwhip effect pattern upstream with the FMCG manufacturer’s TC increasing by as much as €50m. The DES analysis, focusing on the NDC function of the RSC also showed results of TC sensitivity to order behaviour from retailers, although an optimisation based risk treatment has reduced TC by 30%. Future research includes a global empirical validation of the �6 Coefficient and enhancement of the application of thermodynamic laws in business process management. The industry calibration capabilities of the integrated framework application of the integrated framework will also be extensively tested

    Can Themba: The Legacy of a South African Writer

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    The article seeks to explore the world of Can Themba, a foremost literary figure during the era of apartheid. Through an examination of a selection of his short stories we realise that writers often found sub- textual ways of confronting that pernicious system. This article argues that Themba did just that. Finally it also seeks to make problematic issues of labelling and [email protected] Harold Crowe holds a PhD in the Psychology of Education. He was born in Cape Town, South Africa, but brought up and educated in London, UK. He has worked in many countries (the UK, USA, China, Malaysia, Singapore, Jamaica and Zimbabwe) as a teacher, lecturer and principal. His last position was that of Dean in the Faculty of Humanities and Social Sciences at Africa University in Zimbabwe. His research interests include an exploration of South African writing during the Apartheid era with special reference to the literary ways of critiquing the regime. He has published extensively on ways that exploit labelling and notions of superiority in downtrodden communities.Africa University Mutare, ZimbabweBenson, E. and Conally, LW. (eds.) 2005. An Encyclopaedia of Post- Colonial Literatures in English. Second edition. London: Routledge.Chapman, M. 1989. “Can Themba Storyteller and Journalist of the 1550’s: The Text in Context”, English in Africa 16 (2): 19 – 29.Gikandi, S. 2001. “Chinua Achebe and the Intervention of African Culture”, Research in African Literatures Vol. 32 No. 3 Fall 2001.Hannerz, U. 1994. Sophia Town: The View from Afar. Journal of Southern African Studies. 20(2): 181 – 193.Patel, E. (ed.) 1985. The World of Can Themba. South Africa: Raven Press.Snyman, M. 2007. Can Themba: The Life and Work of a Shebeen Intellectual. MA Thesis, Department of English, The University of Johannesburg.Themba, Can. 2006. Requiem for Sophia Town. London: Penguin Books.13-199 (2/2015)131

    Preaching to cultivate a whole-person response in developing a healthy church

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    https://place.asburyseminary.edu/ecommonsatsdissertations/1167/thumbnail.jp

    What makes a good smartphone app for outdoor recreation

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    Applying mobile information and communications technology to countryside access

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    Deploying a spreadsheet tool for early economic value assessment of medical device innovations with healthcare decision makers

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    Early stage evaluation of medical device innovations is important for healthcare decision-makers as much as for manufacturers, meaning that a wider application of a basic cost-effectiveness analysis is becoming necessary outside the usual expert base of health technology assessment specialists. Resulting from an academic-industry-healthcare professional collaboration, a spreadsheet tool is described that was designed to be accessible both to professionals in healthcare delivery organisations and to innovators in the healthcare technology industry who are non-experts in the field of health economics. The tool enables a basic cost-effectiveness analysis to be carried out, using a simplified decision-tree model to compare costs and patient benefit for a new device-related procedure with that of standard care employing an incumbent device or other alternative. Such a tool is useful to healthcare professionals because it enables them to rapidly elucidate the cost-effectiveness of heterogeneous innovations by means of the standard quality adjusted life year (QALY) measure of clinical outcome, which is intended to be broadly comparable across treatments. For the innovator or manufacturer it helps them focus on what is required for future stages of development, in order to fill gaps in the input data and so further strengthen their case from a health economics perspective. Results are presented of first experiences from deploying the tool on three medical device exemplars, in face-to-face meetings of the NHS National Innovation Centre (NIC) along with the innovator or clinical champion. The results show that mapping of device-related innovations to the tool is achievable in a short meeting between the NIC and the innovator using expected costs, outcomes data from the literature and estimates of ranges for unknown input data. Whilst the result of a simplified analysis is not expected to be definitive, the process of reasoning is found to be illuminating for the parties involved, enabling innovators to articulate the benefits of their innovations and for all parties to highlight gaps in data and evidence that will be required to take the innovation forward. The partnership model of the authors’ organisation supports the kind of cooperative design approach that is necessary to produce the kind of tool described.---------------------------7dd39101208fa Content-Disposition: form-data; name="c14_creators_1_name_family" Crave
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