1,960 research outputs found
Konstantinos P. Christou, Byzanz und die Langobarden. Von der Ansiedlung in Pannonien bis zur endgültigen Anerkennung (500-680)
No full textCheynet Jean-Claude. Konstantinos P. Christou, Byzanz und die Langobarden. Von der Ansiedlung in Pannonien bis zur endgültigen Anerkennung (500-680). In: Revue des études byzantines, tome 51, 1993. p. 268
Data for: Reconnaissance of philanthropy
No full textFounded on goodness, the amount of attention given to philanthropy has increased recently. Despite its significance at an organizational and societal level, philanthropy remains a rather obscure notion – a gap that the present study aims to fill. In-depth interviews were conducted with owners of organizations within a rural tourism context who were reciprocally appreciated for their anthropocentricity. The findings reveal that philanthropy should not be restricted to financial aid or charity organizations; it should be expressed with intangible offerings and channeled towards customers and employees alike. Research outcomes enable the construction of a theoretical conceptual diagram guiding both future researchers and managers of organizations that aspire to acquire a more anthropocentric stance
Grid-based virtual laboratory experiments for a graduate course on sensor networks
No full textThis paper presents the pedagogical and technical challenges the authors faced in developing a distributed laboratory for the execution of virtual scientific experiments (VSEs) superimposed on a Grid infrastructure, for a course on sensor networks that is part of the Master's in Information Networking (MSIN) program jointly offered by Carnegie Mellon University (CMU), USA and Athens Information Technology (AIT), Athens, Greece. The MSIN program utilizes virtual classroom technologies because of its strong distance learning component. Courses taught by CMU faculty are attended in real-time by students in Athens, Greece, via video-wall teleconferencing sessions. Vice versa, visiting CMU faculty to AIT teach classes that are attended by students at CMU. Students in both institutions enjoy full interactivity with their classmates on the other side of the Atlantic Ocean. A distributed shared virtual laboratory is needed for many of the more empirical courses. This paper describes the challenges and issues the authors faced in developing such a lab
Grid-Based Interactive Virtual Scientific Experiments for Distributed Virtual Communities
No full textE-learning technologies have matured to a point where distance learning classes are commonly offered from many leading Universities around the world. A major challenge in such distributed classrooms is the formation of virtual communities among the participating students, enhancing the overall learning experience. Shared virtual laboratories offer the possibility of forming such virtual communities as students form lab teams to run the same interactive simulation and in the course of such experiments learn to interact and understand each other better. We have designed and implemented a Virtual Scientific Experiment architectural framework on top of a Grid infrastructure for running interactive virtual laboratory experiments for such distributed student communities with visualization capabilities. The architecture is based on Web Services standard protocols such as WSDL and WS-Notification as implemented in the WSRF specification. For the first concrete instantiation of this architecture, we ported a stand-alone Wireless Sensor Network simulator written in Java in our Grid-based architecture and extended it to allow for initial collaborative parameter setup and on-the-fly visualization of the simulation execution and interaction with it, a capability not present in the original simulator. We report on results from running such simulations on a local Grid infrastructure. System evaluation results from a distributed pool of students show the added value of our system in enhancing distance-learning programs and Virtual Classes with extensible collaborative and interactive Virtual Laboratories sessions
Mixture formation and combustion behaviour analysis in a di ng engine with centrally mounted injector under different injection timings
No full textThe work presented in this paper was carried out by Politecnico di Torino, IFPEN, Renault and Continental within GasOn project of the European commission. The objective of this study has been to understand the fluid-dynamic behaviour in a natural gas engine using direct injection. The first part of the CFD activity has been focused on the characterization of the flow field and its interaction with the jet, with reference to different injection strategies. In the second part the ‘mixture breakdown’ at high speed has been detected, as the highest engine speed at which a sufficiently homogenous mixture can be obtained at the start of combustion. The third one has been related to the discussion of the mixing process and turbulence evolution at low speed and low load. The direct injection of NG in the combustion chamber allows several degrees of freedom to be considered, from the point of view of engine control. At full load, a late injection timing is preferable, whereas at partial load a better mixture quality is obtained for an early injection. For the engine under study, a significant deviation from the mixture homogeneity for engine speeds higher than 4500 rpm, can be detected
Developing the 3DMath dynamic geometry software: theoretical perspectives on design
No full textDesigning successful learning environments entails drawing on theoretical perspectives on learning while, at the same time, being cognisant of the affordances and constraints of the technology. This paper reports on the development of a software environment called 3DMath, a dynamic three-dimensional geometry microworld aimed at enabling learners to construct, observe and manipulate geometrical figures in a 3D-like space. During the development of 3DMath, the key elements of visualisation, including theoretical ideas of mental images, external representations, and the processes and abilities of visualisation, were taken into consideration. The aim of this paper is to illustrate how the design of this particular software was informed by these elements of visualisation, as well as by theories related to the philosophical basis of mathematical knowledge and by semiotics. The paper illustrates how the features of software can be designed to take account of relevant theoretical notions and to satisfy the characteristics of instructional techniques that are appropriate to theoretical perspectives on learning
Investigations into the mechanisms of growth of bloodborne tumour cells at sites of healing and regeneration
No full textThe growth of bloodborne tumour cells in the liver was investigated using a partial hepatectomy (PH) model in rats. Two distinct tumour patterns were observed relating to the time interval between PH and tumour cell delivery. When tumour cells were introduced up to 2 days after PH, tumour grew as a mass at the excision scar; this was attributed to the facilitating effect of trauma on tumour growth. Later times of delivery (3-7 days after PH) gave rise to multiple internal and superficial tumour foci in the regenerating lobes, but no tumour mass at the scar; this was attributed to a facilitating effect of regeneration on tumour growth. Trapping experiments indicated a roughly uniform distribution of tumour cells throughout the liver. Therefore, the presence of tumour mass at the scar was not due to preferential trapping. Cell population studies showed that non-hepatocytes (mesenchymal and endothelial cells) proliferated maximally at 3 and 4 days after PH. Growth factor profiles revealed a peak of heparin binding growth factor at day 2, preceding the proliferation of non-hepatocytes. Non-hepatocytes were prepared from regenerating livers and characterised in vitro. Non-hepatocytes from livers at times of susceptibility to tumour growth in the parenchyma proliferated maximally in vitro. At other times such cells were quiescent. The proliferating population was characterised as fibroblastoid. The same highly proliferating cells significantly enhanced the growth of human colorectal cancer cells in an in vivo xenograft model. In conclusion, the enhanced tumour take at the scar and within the regenerating parenchyma were caused by distinct cellular mechanisms. Furthermore, there was a temporal relationship between the susceptibility of the regenerating liver to tumour growth, the production of growth factors and the appearance and behaviour of highly proliferating fibroblastoid cells, which was consistent with the participation of stromal elements in metastatic growth and with the microinjury hypothesis of metastasis.</p
Enantiodromia by Jani Christou and an Original Composition, Symphony No. 1 .
No full textThis dissertation consists of two parts: an analysis of a composition entitled Enantiodromia by Greek composer Jani Christou as it relates to the general musical style of his late works, and an original composition by the author entitled Symphony No. 1 for full orchestra. The purpose of Part One is to familiarize the reader with Christou\u27s approach to composition, especially as it is evident in his late works. This part is divided into three chapters. In the first chapter attention is given to the biographical background of the composer emphasizing the philosophical influences on his music and providing a chronological delineation of his style periods. In the second chapter specific terms used by the composer in his late period are introduced and concisely defined to enable the reader to understand the composer\u27s compositional techniques. The third chapter is an analysis of the work Enantiodromia for orchestra, a representative composition of Christou\u27s last and most mature period. The analysis includes an explanation of notational devices used in the composition and focuses on events called patterns, which serve as the main structural components of this work. The analysis is based on the function of these patterns, the dynamic and frequency range structure of the piece, the density and rhythmic content, and the interaction of instrumental colors. Part Two of the dissertation is the author\u27s original composition for full orchestra entitled Symphony No. 1 in three movements. The work finds its subject in the idea of Cultural Dependency, a situation often observed in underprivileged nations as they become influenced by cultures of powerful nations. Many musical elements in this work express particular culture-shaping ideas, such as folklore, heroism, hope, struggle, and fear. Compositional techniques such as sound mass, pandiatonicism, atonality, modality, indeterminacy, pointillism, and sound effects are used to represent the aforementioned programmatic ideas. Symphony No. 1 is scored for the following instruments: 1 piccolo, 2 flutes, 3 oboes, 2 clarinets, 2 bassoons, 4 french horns, 3 trumpets, 4 trombones, 1 tuba, 4 percussionists, harp, and strings
A retrospective long-term study on age at menarche and menstrual characteristics in 85 young women with Transfusion-Dependent β-Thalassemia (TDT)
No full textBackground: Menarche is an important milestone in a feminine reproductive life, and regular menstrual cycles reflect normal functioning of the hypothalamic-pituitary-ovarian axis, a vital sign of women's general health. Aim of the study: We explored the age at menarche and the following menstrual cycles characteristics among 85 unmarried Transfusion-Dependent β-Thalassemia (TDT) women, born between 1965 and 1995, concerning iron chelation therapy (ICT) with desferrioxamine (DFO) and nutritional status, assessed by body mass index (BMI). Results: 53 adolescents who had begun ICT before the age of 10 years experienced menarche at 13,7 ± 1,6 years (mean ± DS), whereas 32 who began treatment after ten years experienced menarche significantly later (15.5 ± 1.9 yrs; p: 0.001). At the age of menarche: BMI-Z score (n= 67, - 0,09 ±1) was inversely correlated with both age at starting ICT (r = - 0,39; p = 0001) and age at menarche (- 0,45, p = 0,0001). Serum ferritin levels (SF) were significantly correlated with the age at starting chelation therapy (n = 79; r = 0,34; p = 0,022). In 56 TDT adolescents who developed secondary amenorrhea (SA), the SF levels were significantly higher (4,098 ± 1,907 ng/mL) compared to 23 TDT adolescents with regular menstrual cycles (2,913±782 ng/mL; p = 0,005). Nutritional status of "thinness" at menarche was associated with a lower prevalence of subsequent regular menstrual cycles and a higher prevalence of early SA. Conclusion: An early ICT in TDT patients was associated with a normal "tempo" of pubertal onset and a higher frequency of subsequent regular menstrual cycles. In TDT patients, who developed SA, a diagnosis of acquired central hypogonadism was made, mainly due to the chronic exposure to iron overload, however other potential causes linked to nutritional status, deficient levels of circulating nutrients, and the chronic disease itself cannot be fully excluded
- …
