649 research outputs found

    Finding the right answer: an information retrieval approach supporting knowledge sharing

    Get PDF
    Knowledge Management can be defined as the effective strategies to get the right piece of knowledge to the right person in the right time. Having the main purpose of providing users with information items of their interest, recommender systems seem to be quite valuable for organizational knowledge management environments. Here we present KARe (Knowledgeable Agent for Recommendations), a multiagent recommender system that supports users sharing knowledge in a peer-to-peer environment. Central to this work is the assumption that social interaction is essential for the creation and dissemination of new knowledge. Supporting social interaction, KARe allows users to share knowledge through questions and answers. This paper describes KAReïżœs agent-oriented architecture and presents its recommendation algorithm

    Latin America and East Asia in the Context of an Insurance Model of Currency Crises

    Get PDF
    This paper focuses on the 1995 Latin American and 1997 East Asian crises using an insurance-based model of financial crises. First the model of Dooley (forthcoming) is described. Second, some empirical evidence for an insurance model is presented. The key variables in this approach include the ratio of foreign exchange reserves to bank loans (domestic credit) extended to the private sector, the ability of the private sector to appropriate government assets, and appropriation as measured by capital flight. We argue that the insurance model is consistent with the observed evolution of these variables in the recent crises in Latin America and Asia. Finally, we examine the statistical evidence in favor of the model using panel regressions. We find that the econometric results are consistent with the insurance model, and tend to support this approach over some competing explanations.

    Description of nuclear octupole and quadrupole deformation close to the axial symmetry: Octupole vibrations in the X(5) nuclei 150Nd and 152Sm

    Full text link
    The model, introduced in a previous paper, for the description of the octupole and quadrupole degrees of freedom in conditions close to the axial symmetry, is used to describe the negative-parity band based on the first octupole vibrational state in nuclei close to the critical point of the U(5) to SU(3) phase transition. The situation of 150Nd and 152Sm is discussed in detail. The positive parity levels of these nuclei, and also the in-band E2 transitions, are reasonably accounted for by the X(5) model. With simple assumptions on the nature of the octupole vibrations, it is possible to describe, with comparable accuracy, also the negative parity sector, without changing the description of the positive-parity part.Comment: 8 pages, 5 figure

    Description of nuclear octupole and quadrupole deformation close to the axial symmetry and phase transitions in the octupole mode

    Full text link
    The dynamics of nuclear collective motion is investigated in the case of reflection-asymmetric shapes. The model is based on a new parameterization of the octupole and quadrupole degrees of freedom, valid for nuclei close to the axial symmetry. Amplitudes of oscillation in other degrees of freedom different from the axial ones are assumed to be small, but not frozen to zero. The case of nuclei which already possess a permanent quadrupole deformation is discussed in some more detail and a simple solution is obtained at the critical point of the phase transition between harmonic octupole oscillation and a permanent asymmetric shape. The results are compared with experimental data of the Thorium isotopic chain. The isotope Th-226 is found to be close to the critical point.Comment: 17 pages, 5 figures, 8 tables; 3 new references added, misprints correcte

    Charge Asymmetry in 1-1000 GeV Electromagnetic Showers and Possibility of Its Measurementnt

    Full text link
    For the high energy electromagnetic showers the thickness dependence of a) the development of electron and positron components, b) the difference between the secondary electron and positron numbers, c) the charge asymmetry of high energy electromagnetic showers, as well as d) the spectral distributions of the components at the shower maxima for various energies of primary particle energies,1 - 1000 GeV were investigated employing GEANT Monte Carlo simulation package. Using these simulation results it is discussed the possibility of observation and study of the charge asymmetry with the help of a magnetic spectrometer which is important for the current and future experiments on the detection of radiowaves produced by high energy neutrinos.Comment: TEX file and 4 figure

    Development and Optimization of Osmotically Controlled Oral Drug Delivery Systems for Highly and Poorly Water Soluble Drugs

    Get PDF
    INTRODUCTION: Controlled release drug delivery systems (CRDDS) offer many advantages over conventional dosage forms like improved patient compliance and convenience and reduced adverse effects. A constant therapeutic plasma concentration of the drug within the therapeutic index of the drug over extended periods was maintained in CRDDS. In conventional oral dosage forms, the resulting pattern of concentration of drug in plasma widely varies and this may cause unpredictable and undesired clinical effects. Variations of the blood concentration above the MSC may result in adverse effects. With CR products drug entry with a precise extent, rate, or timing into the blood can be programmed or achieved. Release of the drugs from all other conventional dosage forms except intravenous dosage forms follows first-order kinetics. This results in irregular high and low concentrations and only a brief optimal therapeutic level. But the controlled release systems release the drug at a constant rate (zero order) for a definite time period. This results in consistent concentration of drug in tissue and plasma. In order to maintain blood concentrations within the therapeutic index, frequent dosing will be done for drugs with short half life. Frequency of dosing and patient compliance is inversely related. CR products have the potential to improve patient compliance by reducing the number of daily doses. AIMS OF THE STUDY: For a successful drug therapy the concentration of the drug in the plasma should be maintained constant within the therapeutic index (TI) throughout the treatment period. It avoids the fluctuations in plasma concentration of drug and improves the patient compliance. Diseases which need a longer duration of treatment (sometimes a life time) require more careful medications and drug delivery systems for the better patient compliance and comfort. Controlled release drug delivery systems, release the drug at a controlled and constant manner within the therapeutic index throughout the treatment period. Osmotic pumps are such a device which can strictly maintain a controlled release of the drug in the blood plasma within the therapeutic index up to the desired time period. OBJECTIVES OF THE STUDY: 1. To develop and evaluate an OCODDS (Push pull osmotic tablets) of highly and poorly water soluble drugs. 2. To study and optimize core as well as membrane parameters affecting the release profile using design of experiments (DoE). 3. To compare and conclude the effect of different parameters of the formulation on the release profile/pattern of the selected drugs from the device using different statistical tools. 4. To optimize the push pull osmotic tablet formulation of all the four selected drugs using numerical optimization and desirability techniques. 5. To study the factor influence on the desirability function of highly and poorly soluble drugs. 6. To conduct the stability studies of the selected optimized formulations as per ICH guidelines. 7. To conduct an in vivo animal studies for the selected optimized formulation of all the four drugs. MATERIALS AND METHODS: Study Design: Parallel design. Sample size: 6 healthy rabbits (New Zealand, White) of either sex weighing 3.0 -3.5 kg). Study treatments: Reference (R) – Marketed XR formulation (12mg), Test (T) - Optimized formulation of push pull osmotic tablets of Ropinirole HCl (12mg). Introduction: Ropinirole HCl an orally administered non-ergoline dopamine agonist used for the treatment of Idiopathic Parkinson’s disease. Dose: A single oral dose of either (R) – Marketed XR formulation (12mg) or test treatment (T) Ropinirole HCl push pull OT (12mg), along with water. Dietary Plan: Food was withdrawn from the rats 12 hr before drug administration. Until 24 hr post dosing food was not given to the animals. All rats have access to water during the study period. Sampling Schedules: At defined time intervals blood samples will be collected from marginal ear vein. Bio analytical Method: Ropinirole HCl will be estimated in plasma using a validated analytical method. Pharmacokinetic Parameters: tmax, Cmax, AUC0-t, AUC0-α, kel and t1/2 will be determined from the plasma concentration data of Ropinirole HCl. Ethical: Considerations The study will be carried out as per the ICH- Guidelines. SUMMARY AND CONCLUSION: In this research work, once daily push pull osmotic tablets of two highly soluble drugs (Ropinirole HCl and Ivabradine Hcl) and two poorly soluble drugs (Nisoldipine and Carvedilol phosphate) were developed,optimized and different factors affecting the release profile were extensively studied. The concept of QbD was applied and the design space was successfully obtained with the help of design expert soft ware. Different statistical tools like ANOVA, regression analysis were used for the study. Analytical method was developed in pH 6.8 phosphate buffer for all the selected drugs. The drugs exhibited greater linearity at the selected ranges. Regression equations and R2 were created and studied for all the drugs in both the solvents. Pre formulation studies of the selected drugs like, organoleptic properties, solubility, flow property, particle size determination and drug–excipients interaction study were performed and reported. The amount of the drug to incorporated in to the push pull osmotic tablets of the selected drugs were calculated with the help of the available labeled claim of the XR products and Robinson – eriksen equation. An extensive literature survey was performed and the various vital factors affecting the drug release profile from the push pull OT were identified. Formulation development, factor influence study and optimization of the formulations were done with the help of design expert software. A fractional factorial design (2 8-4 with Resolution IV) with 4 centre points were selected for the study. Push pull OTs of the selected drugs were formulated and both blend as well as whole tablet evaluations were performed. All the tests were within specified limits of the pharmacopoeia. In vitro dissolution study of all the trials of the selected drugs were carried out in triplicate. The selected responses like PCUR at 24 hrs, lag time and R2 were reported for each trial. The responses were analyzed with the help of design expert software and different significant factors affecting the selected responses were identified. The factor influences were extensively studied and reported with the help of different plots like half normal plot, normal plots, Pareto charts, contour plots, RS plots and cube plots. ANOVA analysis was also performed for the identification significant factors. From the regression analysis the coefficients of significant factors were determined. Polynomial equations representing the responses were framed after eliminating the non significant factors. Optimization of the push pull OTs of the selected drugs was done with the help of numerical optimization and desirability function. A better identification of design space was done with the help of desirability contour plots and RS plots. Check point batches of all the four selected drugs were formulated and evaluated for the design model validity. Stability studies on the optimized push pull OT formulations of all the selected drugs were performed to assess their stabilityover time. The ICH guidelines were strictly followed during the stability study. None of the formulations showed any significant changes in any of the parameters evaluated. An In vivo animal study of the optimized formulations of all the selected drugs was performed to assess the in vivo performance of the dosage form. Pharmacokinetic parameters like tmax,Cmax, AUC0-t,AUC 0-∞,Kel, tÂœ were determined and compared with the available marketed products of the selected drugs. So it can be concluded that in this research work, stable optimized formulations of push pull OTs of highly and poorly soluble drugs were successfully formulated and extensively studied the significant factors affecting the release pattern of the drug from the system with the help of design of experiments

    Sistem Insulasi Termal Sebagai Dasar Perancangan Pasar Ikan Higienis Di Sendang Biru

    Full text link
    Pasar ikan di Indonesia umumnya berfungsi kurang optimal karena masih bersifattradisional. Kondisi pasar ikan tradisional umumnya bau, kotor, dan becek, sehinggamenyebabkan konsumen lebih memilih untuk berbelanja di pasar swalayan, khususnyamasyarakat dari golongan ekonomi menengah ke atas. Oleh karena itu, saat ini Pasar IkanHigienis sangat diperlukan di Indonesia. Di Jawa Timur, potensi pengembangan pasar ikanyang berorientasi higienis adalah Pasar Ikan Sendang Biru, Kabupaten Malang.Berdasarkan hasil wawancara, permasalahan yang sering dihadapi adalah kurangnyahigienitas akibat kondisi fisik bangunan dan sanitasi yang tidak sesuai dengan ketentuanpasar sehat. Jenis ikan pelagis besar yang merupakan komoditas utama di Sendang Biruadalah ikan tuna, namun penanganan pada ikan tersebut tidak higienis. Perlu adanyapenanganan khusus pada tempat penjualan ikan pelagis besar agar kualitas ikan tetapterjaga. Oleh karena itu, perancangan Pasar Ikan Higienis ini melalui pendekatan sisteminsulasi termal yang difokuskan untuk menjaga suhu agar kesegaran ikan tetap terjaga.Perancangan Pasar Ikan Higienis di Sendang Biru ini menggunakan metode perancangan,yaitu metode kanonik dan metode pragmatik. Perancangan Pasar Ikan Higienis denganmenggunakan metode tersebut diharapkan dapat menghasilkan suatu rancangan yanghigienis dan memenuhi kebutuhan Pasar Ikan Sendang Biru. Hasil akhir merupakanrancangan Pasar Ikan Higienis dengan dasar sistem insulasi termal
    • 

    corecore