777 research outputs found

    Shifts in Portfolio Preferences of International Investors: An Application to Sovereign Wealth Funds

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    Reversals in capital inflows can have severe economic consequences. This paper develops a dynamic general equilibrium model to analyse the effect on interest rates, asset prices, investment, consumption, output, the exchange rate and the current account of a shift in portfolio preferences of foreign investors. The model has two countries and two asset classes (equities and bonds). It is characterized by imperfect substitutability between assets and allows for endogenous adjustment in interest rates and asset prices. Therefore, it accounts for capital gains arising from equity price movements, in addition to valuation effects caused by changes in the exchange rate. To illustrate the mechanics of the model, we calibrate it to analyse the consequences of an increase in the importance of Sovereign Wealth Funds (SWFs). Specifically, we ask what would happen if 'excess' reserves held by Emerging Markets were transferred from central banks to SWFs. We look separately at two diversification paths: one in which SWFs keep the same allocation across bonds and equities as central banks, but move away from dollar assets (path 1); and another in which they choose the same currency composition as central banks, but shift from US bonds to US equities (path 2). In path 1, the dollar depreciates and US net debt falls on impact and increases in the long run. In path 2, the dollar depreciates and US net debt increases in the long run. In both cases, there is a reduction in the 'exorbitant privilege', i.e., the excess return the US receives on its assets over what it pays on its liabilities. The model is applicable to other episodes in which foreign investors change the composition of their portfolios

    Understanding Link Dynamics in Wireless Sensor Networks with Dynamically Steerable Directional Antennas

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    Abstract. By radiating the power in the direction of choice, electronicallyswitched directional (ESD) antennas can reduce network contention and avoid packet loss. There exists some ESD antennas for wireless sensor networks, but so far researchers have mainly evaluated their directionality. There are no studies regarding the link dynamics of ESD antennas, in particular not for indoor deployments and other scenarios where nodes are not necessarily in line of sight. Our long-term experiments confirm that previous findings that have demonstrated the dependence of angleof-arrival on channel frequency also hold for directional transmissions with ESD antennas. This is important for the design of protocols for wireless sensor networks with ESD antennas: the best antenna direction, i.e., the direction that leads to the highest packet reception rate and signal strength at the receiver, is not stable but varies over time and with the selected IEEE 802.15.4 channel. As this requires protocols to incorporate some form of adaptation, we present an intentionally simple and yet efficient mechanism for selecting the best antenna direction at run-time with an energy overhead below 2 % compared to standard omni-directional transmissions.

    Wireless Sensor Network Deployment for Monitoring Soil Moisture Dynamics at the Field Scale

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    AbstractWe describe the deployment of a Wireless Sensor Network (WSN), composed of 135 soil moisture and 27 temperature sensors, in an apple tree orchard of about 5000 m2, located in the municipality of Cles, a small town in the Alpine region, northeastern Italy. The orchard is divided into three parcels each one subjected to a different irrigation schedule. The objective of the present work is to monitor soil moisture dynamics in the top soil to a detail, in both space and time, suitable to analyze the interplay between soil moisture dynamics and plant physiology. The deployment consists of 27 locations (verticals) connected by a multi hop WSN, each one equipped with 5 soil moisture sensors deployed at the depths of 10, 20, 30, 50 and 80 cm, and a temperature sensor at the depth of 20 cm. The proposed monitoring system is based on totally independent sensor nodes, which allow both real time and historic data management and are connected through an input/output interface to a WSN platform. Meteorological data are monitored by a weather station located at a distance of approximately 100 m from the experimental site.Great care has been posed to calibration of the capacitance sensors, both in the laboratory, with soil samples, and on site, after deployment, in order to minimize the noise caused by small oscillations in the input voltage and uncertainty in the calibration curves. In this work we report the results of a preliminary analysis on the data collected during the growing season 2009. We observed that the WSN greatly facilitates the collection of detailed measurements of soil moisture, thereby increasing the amount of information useful for exploring hydrological processes, but they should be used with care since the accuracy of collected data depends critically on the capability of the system to maintain constant the input voltage and on the reliability of calibration curves. Finally, we studied the spatial and temporal distribution of soil moisture in all the irrigated parcels, and explored how different irrigation schedules influence orchard's production

    Design of a novel LOX-1 receptor antagonist mimicking the natural substrate

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    The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), the major receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, is overexpressed in atherosclerotic lesions. LOX-1 specific inhibitors, urgently necessary to reduce the rate of atherosclerotic and inflammation processes, are not yet available. We have designed and synthesized a new modified oxidized phospholipid, named PLAzPC, which plays to small scale the ligand-receptor recognition scheme. Molecular docking simulations confirm that PLAzPC disables the hydrophobic component of the ox-LDL recognition domain and allows the interaction of the l-lysine backbone charged groups with the solvent and with the charged/polar residues located around the edges of the LOX-1 hydrophobic tunnel. Binding assays, in a cell model system expressing human LOX-1 receptors, confirm that PLAzPC markedly inhibits ox-LDL binding to LOX-1 with higher efficacy compared to previously identified inhibitors

    A Smart Bluetooth-based Ad Hoc Management System for Appliances in Home Environments

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    The number of home devices integrating new technologies is continuously increasing. These advances allow us to improve our daily routines. In addition, the improvement in network infrastructure and the development of smart phones and mobile devices allow us access from any place to any of our systems over the Internet. Bearing in mind this idea, we have developed a low-cost ad hoc protocol based on Bluetooth technology that allows us to control all our home appliances and monitor the power consumption of our homes. Our proposal is based on an Android application installed on a mobile device which acts as server. The application allows users to program the various appliances. It is also able to check the status of the appliance, as well as controlling the power consumption of the house and its cost. The system is equipped with a smart algorithm able to manage all appliances and decide which ones should work as a function of various criteria such as time of day or power consumption. Finally, the system is able to detect faults in water and electricity supply for acting accordingly. All data received and sent by the server are stored in a database which the system can check and compare to make their own decisions.Sendra, S.; Laborda, A.; Díaz Santos, JR.; Lloret, J. (2015). A Smart Bluetooth-based Ad Hoc Management System for Appliances in Home Environments. Springer Verlag (Germany): LNCS. 8487:128-141. doi:10.1007/978-3-319-07425-2_10S1281418487Garcia, M., Sendra, S., Lloret, J., Canovas, A.: Saving energy and improving communications using cooperative group-based Wireless Sensor Networks. Telecommunication Systems 52(4), 2489–2502 (2013)Liu, Y., Zhou, G.: Technologies and Applications of Internet of Things. In: Proceedings of 2012 Fifth International Conference on Intelligent Computation Technology and Automation (ICICTA), Zhangjiajie, China, January 12-14, pp. 197–200 (2012)Aiello, M.: The Role of Web Services at Home. In: Proceedings of the Advanced International Conference on Telecommunications and International Conference on Internet and Web Applications and Services (AICT-ICIW 2006), Guadeloupe, France, February 23-25 (2006)Mowafi, M.Y., Awad, F.H., Al-Batati, M.A.: Opportunistic Network Coding for Real-Time Transmission over Wireless Networks. Network Protocols and Algorithms 5(1), 1–19 (2013)Gangadhar, G., Nayak, S., Puttamadappa, C.: Intelligent Refrigerator with monitoring capability through internet. International Journal of Computer Applications. Special Issue on “Wireless Information Networks & Business Information System 2(7), 65–68 (2011)Soucek, S., Russ, G., Tamarit, C.: The Smart Kitchen Project—An Application of Fieldbus Technology to Domotics. In: Proceedings of 2nd International Workshop on Networked Appliances (IWNA 2000), New Brunswick, NJ, USA, November 30-December 1 (2000)Zhang, W., Tan, G.-Z., Ding, N.: Traffic Information Detection Based on Scattered Sensor Data: Model and Algorithms. Adhoc & Sensor Wireless Networks 18(3-4), 225–240 (2013)Ranjit, J.S., Shin, S.: A Modified IEEE 802.15. 4 Superframe Structure for Guaranteed Emergency Handling in Wireless Body Area Network. Network Protocols & Algorithms 5(2), 1–15 (2013)Braeken, A., Singelee, D.: Efficient and Location-Private Communication Protocols for WBSNs. Adhoc & Sensor Wireless Networks 19(3-4), 305–326 (2013)Augusto, J.C., McCullagh, P., McClelland, V., Walkden, J.A.: Enhanced healthcare provision through assisted decision-making in a smart home environment. In: Proceedings of the Second Workshop on Artificial Intelligence Techniques for Ambient Intelligence (AITAmI 2007), Hyderabad, India, January 6-7 (2007)Zhang, L., Zhao, Z., Li, D., Liu, Q., Cui, L.: Wildlife Monitoring Using Heterogeneous Wireless Communication Network. Adhoc & Sensor Wireless Networks 18(3-4), 159–179 (2013)Viani, F., Robol, F., Polo, A., Rocca, P., Oliveri, G., Massa, A.: Wireless Architectures for Heterogeneous Sensing in Smart Home Applications: Concepts and Real Implementation. Proceedings of the IEEE 101(11), 2381–2396 (2013)Lloret, J., Macías, E., Suárez, A., Lacuesta, R.: Ubiquitous Monitoring of Electrical Household Appliances. Sensors 12(11), 15159–15191 (2012)Kamilaris, A., Trifa, V., Pitsillides, A.: The smart home meets the Web of Things. International Journal of Ad Hoc and Ubiquitous Computing 7(3), 145–154 (2011)Kamilaris, A., Trifa, V., Pitsillides, A.: An Application Framework for Web-Based Smart Homes. In: Proceedings of the 18th International Conference on Telecommunications, ICT 2011, Ayia Napa, Cyprus, May 8-11, pp. 134–139 (2011)IEEE Std 802.15.1-2002 – IEEE Standard for Information technology – Telecommunications and information exchange between systems – Local and metropolitan area networks – Specific requirements Part 15.1: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Wireless Personal Area Networks (WPANs)KNX international Site, http://www.knx.org/knx-en/index.php (last access: February 1, 2014)LonWorks Technology. In: ECHELON web site, http://www.echelon.com/technology/lonworks/ (last access: February 1, 2014)X10 protocol. In: X10 web site, http://x10-lang.org/ (last access: February 1, 2014)Rohini Basak, R., Sardar, B.: Security in Network Mobility (NEMO): Issues, Solutions, Classification, Evaluation, and Future Research Directions. Network Protocols and Algorithms 5(2), 87–111 (2013

    Gene polymorphism of interleukin 1 and 8 in chronic gastritis patients infected with Helicobacter pylori

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    Background: Epidemiological investigations have indicated that Helicobacter pylori induces inflammation in the gastric mucosa regulated by several interleukins. The genes IL1B and IL8 are suggested as key factors in determining the risk of gastritis. The aim of this paper was to evaluate the association of gene polymorphism of interleukin-1 and interleukin-8 with chronic gastrits in H. pylori infected patients. A total of 60 patients underwent endoscopic procedure. Biopsy samples were collected for urease test, histopathological and molecular exams. The DNA of theses samples was extracted for detection of H. pylori and analysis of the genes mentioned above. Patients with gastritis had a higher frequency of H. pylori-positive samples. Result: H. pylori was detected in 30/60 patients (50%) by PCR. As for polymorphism of interleukin 8 (-251) gene we observed a statistical difference when analyzed TA (p = 0.039) and TT (p = 0.047) genotypes. In the IL1B31 there was a statistical difference in TT (p = 0.01) genotype and in theIL1B-511 there wasn’t any statistical difference. Conclusion: Our results suggest a strong correlation between the presence of chronic gastritis and infection byH. pylori and that IL1B-31TT and IL8-251TT genotypes appear to act as protective factors againstH. pylori infection while IL8-251TA genotype may comprise a risk factor for infection with this bacterium.Marília Medical School FAMEMA Blood Center Department of GeneticsSacred Heart UniversityMarília Medical School Department of Digestive System SurgeryFederal University of São Paulo Department of MorphologyMarília Medical School Department of Radiotherapy and OncologyFAMEMA Hemocentro Laboratório de GenéticaUNIFESP, Department of MorphologySciEL

    High-risk surgical stage 1 endometrial cancer: analysis of treatment outcome

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    PURPOSE: To report the relapse and survival rates associated to treatment for patients with stage IC, grade 2 or grade 3 and IB grade 3 diseases considered high risk patients group for relapse. MATERIALS AND METHODS: From January 1993 to December 2003, 106 patients with endometrial cancer stage I were managed surgically in our institution. Based on data from the medical records, 106 patients with epithelial endometrial cancer met the following inclusion criteria: stage IC grade 2 or 3 and IB grade 3 with or without lymphovascular invasion. Staging was defined according to the FIGO surgical staging system. Postoperative adjuvant radiotherapy consisted of external beam pelvic radiation, vaginal brachytherapy alone or both. The median age was 65 years (range, 32–83 years), lymph node dissection was performed in 45 patients (42.5%) and 14 patients (13.2%) received vaginal brachytherapy only, and 92 (86.8%) received combined vaginal brachytherapy and external beam radiotherapy. The median dose of external beam radiotherapy administered to the pelvis was 4500 cGy (range 4000 – 5040). The median dose to vaginal surface was 2400 cGy (range 2000 – 3000). Predominant pathological stage and histological grade were IC (73.6%) and grade 3 (51.9%). The lymphovascular invasion was present in 33 patients (31.1%) and pathological stage IC grade 2 was most common (48. 1%) combination of risk factors in this group. RESULTS: With a follow up median of 58.3 months (range 12.8 – 154), five year overall survival and event free survival were 78.5% and 72.4%, respectively. Locoregional control in five year was 92.4%. Prognostic factors related with survival in univariate analyses were: lymphadenectomy (p = 0.045), lymphovascular invasion (p = 0.047) and initial failure site (p < 0.0001). In multivariate analyses the initial failure in distant sites (p < 0.0001) was the only factor associated with poor survival. Acute and chronic gastrointestinal and genitourinary toxicity grades 3 were not observed. CONCLUSION: In conclusion, our results showed that the stage IC, grade 2, 3 and IB grade 3 endometrial cancer was associated with significantly increased risk of distant relapse and endometrial carcinoma-related death independently of salvage treatment modality
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