Bibliometric cartography of information retrieval research by using co-word analysis

The aim of this study is to map the intellectual structure of the field of Information Retrieval (IR) during the period of 1987-1997. Co-word analysis was employed to reveal patterns and trends in the IR field by measuring the association strengths of terms representative of relevant publications or other texts produced in IR field. Data were collected from Science Citation Index (SCI) and Social Science Citation Index (SSCI) for the period of 1987-1997. In addition to the keywords added by the SCI and SSCI databases, other important keywords were extracted from titles and abstracts manually. These keywords were further standardized using vocabulary control tools. In order to trace the dynamic changes of the IR field, the whole 11-year period was further separated into two consecutive periods: 1987-1991 and 1992-1997. The results show that the IR field has some established research themes and it also changes rapidly to embrace new themes

An architecture of a user-centred digital library for the academic community

An architecture of a user-centred digital library, designed to lead users of an academic community to the required information resources based on their tasks, is proposed. Information resources include full-text articles, databases, theses and dissertations, e-journals, e-books, multimedia databases, and so on. Other information resources such as university course calendars, university statutes, course registration, thesis and dissertation guidelines, style guides, and so on, are also needed by users. A prototype has been designed and developed using the School of Computer Engineering at Nanyang Technological University (NTU) as an example of such an environment to provide access to these information resources which are spread across different servers and in different home pages This prototype provides links to various information resources according to users' needs, as well as a personal work space to record/store his/her publications, frequently used or favorite hyperlinks and references or notes. Various stages of the prototype design and development are described and future works on this line are highlighted

Dynamic reasoning in a knowledge-based system

Any space based system, whether it is a robot arm assembling parts in space or an onboard system monitoring the space station, has to react to changes which cannot be foreseen. As a result, apart from having domain-specific knowledge as in current expert systems, a space based AI system should also have general principles of change. This paper presents a modal logic which can not only represent change but also reason with it. Three primitive operations, expansion, contraction and revision are introduced and axioms which specify how the knowledge base should change when the external world changes are also specified. Accordingly the notion of dynamic reasoning is introduced, which unlike the existing forms of reasoning, provide general principles of change. Dynamic reasoning is based on two main principles, namely minimize change and maximize coherence. A possible-world semantics which incorporates the above two principles is also discussed. The paper concludes by discussing how the dynamic reasoning system can be used to specify actions and hence form an integral part of an autonomous reasoning and planning system

Distribution and connectivity of messenger molecules in the control of energy metabolism : focus on neuropeptides and calcium binding proteins

Feeding is an essential and complex behavior which aims to provide the energy required for maintaining physiological homeostasis. The drive to feed is a powerful stimulus arising from metabolic demands, and reinforced by evolutionary pressure. The current epidemic in obesity, and associated disorders such as diabetes, makes it clinically vital to understand the mechanisms behind the control of energy metabolism. Feeding is a process governed by the central nervous system (CNS); particularly through the interplay between different hypothalamic nuclei. At the heart of the feeding neuro-circuitry lies the arcuate nucleus (ARC) which acts as a metabolic sensor, taking stock of the supply and demands of energy in the body, and coordinating food intake and energy expenditure. The work in this thesis aimed to explore the neuro-anatomical substrate of metabolic control, and the mediators involved. The ARC contains two distinct sets of functionally antagonistic neurons. One group of neurons express the orexigenic peptides, neuropeptide Y (NPY) and agouti gene related peptide (AGRP); while the other set expresses the anorexigenic peptides, proopiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript. In paper V, we describe the histochemistry of NPY/AGRP and POMC neurons with regard to their anatomical interrelationship at the cell body and terminal level. A common experimental problem is that the ARC NPY cell bodies are difficult to distinguish and visualize in electrophysiological experiments and for immunohistochemistry. Therefore, in paper III, a novel transgenic mouse which expresses bright Renilla green fluorescent protein in NPY neurons was generated. Using this model, a comprehensive map of NPY-expressing cells in the CNS was generated and the effects of the satiety-inducing gut-brain bombesin peptides on ARC neurons were explored. Bombesin was found to exert powerful depolarizing actions on NPY and POMC neurons alike. Calcium binding proteins (CaBPs) have been used extensively to delineate neuronal populations, but the ARC has not yet been subjected to such analysis. In Paper IV we show that three major CaBPs (calbindin D-28k, calretinin, and parvalbumin) are all expressed in the ARC, but displayed little co-localization with previously described cell groups. One exception was POMC neurons, of which distinct subpopulations stained for calbindin D-28k and calretinin, respectively. Another CaBP, nucleobindin 2 (NUCB2; also known as nesfatin), has recently been proposed as a central anorexigenic mediator. In Paper I, the CNS distribution of this protein was shown to include nuclei that participate in all three output channels of metabolic control, i.e. behavioral, endocrine and autonomic modulation. Our data also suggest that NUCB2 may not act as a cleaved and secreted messenger as proposed, but rather may play an intracellular role. The wide distribution of NUCB2 in the neuroendocrine system prompted us to explore this protein in the pancreas (Paper II). We show that NUCB2 is exclusively expressed in insulin-producing β cells, and that islet NUCB2 is dramatically decreased in the diabetic Goto-Kakizaki rat, an effect that is normalized by fasting. These data indicate that NUCB2 may play a role in metabolic control also outside of the CNS

Patient-Related Barriers to Timely Dialysis Access Preparation: A Qualitative Study of the Perspectives of Patients, Family Members, and Health Care Providers

Rational & Objective A key aspect of smooth transition to dialysis is the timely creation of a permanent access. Despite early referral to kidney care, initiation onto dialysis is still suboptimal for many patients, which has clinical and cost implications. This study aimed to explore perspectives of various stakeholders on barriers to timely access creation. Study Design Qualitative study. Setting & Participants Semi-structured interviews with 96 participants (response rate, 67%), including patients with stage 4 chronic kidney disease (n = 30), new hemodialysis patients with (n = 18) and without (n = 20) permanent access (arteriovenous fistula), family members (n = 19), and kidney health care providers (n = 9). Analytical Approach Thematic analysis. Results Patients reported differential levels of behavioral activation toward access creation: avoidance/denial, wait and see, or active intention. 6 core themes were identified: (1) lack of symptoms, (2) dialysis fear and practical concerns (exaggerated fear, pain, cost, lifestyle disruptions, work-related concerns, burdening their families), (3) evaluating value against costs/risks of access creation (benefits, threat of operation, viability, prompt for early initiation), (4) preference for alternatives, (5) social influences (hearsay, family involvement, experiences of others), and (6) health care provider interactions (mistrust, interpersonal tension, lack of clarity on information). Themes were common to all groups, whereas nuanced perspectives of family members and health care providers were noted in some subthemes. Limitations Response bias. Conclusions Individual, interpersonal, and psychosocial factors compromise dialysis preparation and contribute to suboptimal dialysis initiation. Our findings support the need for interventions to improve patient and family engagement and address emotional concerns and misperceptions about preparing for dialysis

Development of a Friction Rig and Experimental Results

The development of a friction rig, which is integrated into a milling machine for testing the frictional characteristics of various types of materials and specimen shapes are described. This is followed by the experimental technique used to measure the friction coefficient for different experimental conditions. The results obtained indicate the frictional coefficient obtained changes with the specimen type, contact area and lubrication condition. The results obtained are also compared to available published results. The discussions and conclusions related to the development and experimental results are finally presented

Risk factors for complications after colonic stent insertion for large bowel obstruction

This journal suppl. entitled: DDW 2014 ASGE Program and AbstractsBACKGROUND: Colonic stenting is proven to be an effective means in relieving malignant large bowel obstruction. However, severe complication such as perforation of bowel and subsequently fecal peritonitis can occur after successful of insertion of colonic stent. While colonic stenting is practiced more widely, concern also arises as a result of reports on increased complication rate from this procedure ...postprin

Foreign direct investment and investment environment in Dongguan Municipality of southern China

Based on 26 case studies, this paper investigates the socio-economic causes of the inflow of FDI and its policy implications in Dongguan. The favourable factors for foreign investors in Dongguan can be categorised under the Dunning's OLI (ownership, locational and internalisation advantages) framework. This paper argues that factors other than policy incentive, such as sub-contractual and pseudo integration, are playing more important roles in attracting the inflow of FDI and maintaining the high level of economic growth in Dongguan. This finding questions the effectiveness of policy incentives, such as tax-breaks, implemented by the Government as a means to attract FDI in Dongguan. The existence of 'Chinese crony capitalism' calls for further improvement in the implementation of laws and regulations in Dongguan and the reduction of bureaucratic red-tape by the central and local governments

Wideband outdoor MIMO channel model derived from directional channel measurements at 2 GHz

This paper describes the use of directional channel measurements to derive a MIMO channel model. The measurements were obtained using a wideband channel sounder and eight element circular array in a metropolitan area in central Bristol, U.K. The raw measurements were processed using SAGE to extract the parameters of multipath components. The analysis of these parameters revealed several interesting features, notably that their amplitude distribution was well modelled as log-normal, and that there was little evidence of clustering in the angles of arrival. Hence a MIMO channel based on the assumption of finite scattering was derived, using the distributions obtained. The model allows the channel matrix H to be derived in the narrow-band case, and a tapped delay line model is also obtained for wideband systems. While the model derived is based on only a small set of measurements, it provides a case study for MIMO modelling based on measurements

Synthesis and characterization of Na03RhO206H2O - a semiconductor with a weak ferromagnetic component

We have prepared the oxyhydrate Na03RhO206H2O by extracting Na+ cations from NaRhO2 and intercalating water molecules using an aqueous solution of Na2S2O8. Synchrotron X-ray powder diffraction, thermogravimetric analysis (TGA), and energy-dispersive x-ray analysis (EDX) reveal that a non-stoichiometric Na03(H2O)06 network separates layers of edge-sharing RhO6 octahedra containing Rh3+(4d6, S=0) and Rh4+ (4d5, S=1/2). The resistivities of NaRhO2 and Na03RhO206H2O (T < 300) reveal insulating and semi-conducting behavior with activation gaps of 134 meV and 7.8 meV, respectively. Both Na03RhO206H2O and NaRhO2 show paramagnetism at room temperature, however, the sodium-deficient sample exhibits simultaneously a weak but experimentally reproducible ferromagnetic component. Both samples exhibit a temperature-independent Pauli paramagnetism, for NaRhO2 at T > 50 K and for Na03RhO206H2O at T > 25 K. The relative magnitudes of the temperature-independent magnetic susceptibilities, that of the oxide sample being half that of the oxyhydrate, is consistent with a higher density of thermally accessible electron states at the Fermi level in the hydrated sample. At low temperatures the magnetic moments rise sharply, providing evidence of localized and weakl -ordered electronic spins.Comment: 15 fages 5 figures Solid State Communications in prin