2,369 research outputs found

    Topologies of wireless mesh networks with inband backhauling

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    Proceedings of: PIMRC 2010: 21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications took place from 26-30 Sep. 2010 in Istanbul, TurkeyWireless mesh networks (WMNs) with in band backhauling use the same antennas for the backhaul as well as for the access. Therefore antennas of next hop neighbours need to be directed to each other. However, such a configuration is not possible in a three-sectorized hexagonal cell deployment. In this paper we derive several alternative topologies that are suitable for WMNs with in band backhauling. We show that a topology with four directional antennas per node and backhaul connectivity between indirect neighbours outperforms competing topologies in terms of handover rate, optimal maximum power, and system capacity.European Community's Seventh Framework ProgramPublicad

    Angiopoietin-1 and keratinocyte growth factor restore the impaired alveolar fluid clearance induced by influenza H5N1 virus infection

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    Poster Session: Novel TherapeuticsBackground: Acute respiratory distress syndrome (ARDS) caused by high pathogenic avian influenza (HPAI) H5N1 virus infection has resulted in severe illness and high mortality rates among patients. Patients with ARDS are often characterized by impaired alveolar fluid clearance and alveolar edema. An understanding of the mechanism responsible for human alveolar edema will lead to the development of novel therapeutic treatments for ARDS patients. We hypothesized that the paracrine soluble factors angiopoietin-1 (Ang-1) and keratinocyte growth factor (KGF) can resolve alveolar fluid clearance by up-regulating the expression of major sodium and chloride transporters impaired by HPAI H5N1 virus infection. Materials and Methods: Human alveolar epithelial cells grown on transwell inserts were infected with HPAI H5N1 (A/HK/483/97) and low pathogenic avian influenza (LPAI) H1N1 (A/HK/54/98) viruses at MOI 0.1 or incubated with conditioned culture medium containing Ang-1 and/or KGF. At 24 and 48 h post-infection, the rate of alveolar fluid transport and protein permeability across the alveolar epithelium was measured. Protein expression of sodium and chloride transporters (Na-K-ATPase, CFTR, and epithelial sodium channel alpha subunit) was measured by qPCR, ELISA, and Western blot. Results: HPAI H5N1 (A/HK/483/97) virus infection significantly reduced net alveolar fluid transport and protein permeability when compared with H1N1 (A/HK/54/98) virus infection at 24 h post-infection and further reduced it at 48 h post-infection. This reduction in alveolar fluid clearance was associated with a substantial reduction in protein expression of Na-K-ATPase, CFTR, and epithelial sodium channel alpha subunit. The influenza virus–infected cells treated with Ang-1 and KGF restored the impaired alveolar edema fluid clearance and protein permeability after HPAI H5N1 virus infection. Furthermore, the paracrine soluble factors Ang-1 and KGF up-regulated the protein expression of the major sodium and chloride transporters resulting from the HPAI influenza virus infection. Conclusions: The paracrine soluble factors Ang-1 and KGF play an important role in maintaining human alveolar fluid clearance by up-regulating the sodium and chloride transporting systems in human alveolar epithelium. This study enriches the understanding of the development of ARDS in human H5N1 disease and may aid in the development of possible therapeutic applications.published_or_final_versio

    Family Unification, Exotic States and Light Magnetic Monopoles

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    Models with fermions in bifundamental representations can lead naturally to family unification as opposed to family replication. Such models typically predict (exotic) color singlet states with fractional electric charge, and magnetic monopoles with multiple Dirac charge. The exotics may be at the TeV scale, and relatively light magnetic monopoles (greater than about 10^7 GeV) can be present in the galaxy with abundance near the Parker bound. We focus on three family SU(4)XSU(3)XSU(3) models.Comment: 37 page

    Investigation on iterative multiuser detection physical layer network coding in two-way relay free-space optical links with turbulences and pointing errors

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    Physical layer network coding (PNC) improves the throughput in wireless networks by enabling two nodes to exchange information using a minimum number of time slots. The PNC technique is proposed for two-way relay channel free space optical (TWR-FSO) communications with the aim of maximizing the utilization of network resources. The multipair TWR-FSO is considered in this paper, where a single antenna on each pair seeks to communicate via a common receiver aperture at the relay. Therefore, chip interleaving is adopted as a technique to separate the different transmitted signals at the relay node to perform PNC mapping. Accordingly, this scheme relies on the iterative multiuser technique for detection of users at the receiver. The bit error rate (BER) performance of the proposed system is examined under the combined influences of atmospheric loss, turbulence-induced channel fading, and pointing errors (PEs). By adopting the joint PNC mapping with interleaving and multiuser detection techniques, the BER results show that the proposed scheme can achieve a significant performance improvement against the degrading effects of turbulences and PEs. It is also demonstrated that a larger number of simultaneous users can be supported with this new scheme in establishing a communication link between multiple pairs of nodes in two time slots, thereby improving the channel capacity

    Wall Crossing and Instantons in Compactified Gauge Theory

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    We calculate the leading weak-coupling instanton contribution to the moduli-space metric of N=2 supersymmetric Yang-Mills theory with gauge group SU(2) compactified on R^3 x S^1. The results are in precise agreement with the semiclassical expansion of the exact metric recently conjectured by Gaiotto, Moore and Neitzke based on considerations related to wall-crossing in the corresponding four-dimensional theory.Comment: 24 pages, no figure

    IoT-Based Indoor and Outdoor Self-Quarantine System for COVID-19 Patients

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    Even after two years since the declaration of the new virus Coronavirus Disease 19 (COVID-19), the reported cases are still considerably high in many countries, including Malaysia. The health authorities cannot monitor the health condition and track the location of every home-monitored patient at once due to many confirmed cases in a day. In order to overcome the shortage of manpower, an Internet of Things (IoT)-based self-quarantine system with Radio Frequency Identification (RFID) and Global Positioning System (GPS) tracking is proposed in this paper to monitor the health conditions of the Covid-19 patients and track their real-time location via mobile application. Biomedical sensors are used to measure health conditions such as temperature, pulse oximetry, and heart-rate monitor. In addition, the RFID readers are used to detect patients that intend to leave the quarantine area, and the GPS modules are used to track their actual geometrical location so that the authorities can take further action. The real-time data is automatically pushed to the cloud server for the authorities to remotely view the patient's health condition and location on the Google map using smart devices. Finally, a hardware prototype and a mobile application have been successfully developed in this project. The system is able to display the temperature, heartbeats, and blood oxygen saturation properly on a liquid crystal display (LCD) screen. All these measured values, together with the information from RFID detection and GPS location tracking, can be viewed on a smartphone

    Skeletal Muscle Ultrasonography in Nutrition and Functional Outcome Assessment of Critically Ill Children: Experience and Insights From Pediatric Disease and Adult Critical Care Studies

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    This is the peer reviewed version of the following article: [FULL CITE], which has been published in final form atOng, C. , Lee, J. H., Leow, M. K. and Puthucheary, Z. A. (2017), Skeletal Muscle Ultrasonography in Nutrition and Functional Outcome Assessment of Critically Ill Children: Experience and Insights From Pediatric Disease and Adult Critical Care Studies. Journal of Parenteral and Enteral Nutrition, 41: 1091-1099. doi:10.1177/0148607116683143. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Version

    The projection score - an evaluation criterion for variable subset selection in PCA visualization

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    <p>Abstract</p> <p>Background</p> <p>In many scientific domains, it is becoming increasingly common to collect high-dimensional data sets, often with an exploratory aim, to generate new and relevant hypotheses. The exploratory perspective often makes statistically guided visualization methods, such as Principal Component Analysis (PCA), the methods of choice. However, the clarity of the obtained visualizations, and thereby the potential to use them to formulate relevant hypotheses, may be confounded by the presence of the many non-informative variables. For microarray data, more easily interpretable visualizations are often obtained by filtering the variable set, for example by removing the variables with the smallest variances or by only including the variables most highly related to a specific response. The resulting visualization may depend heavily on the inclusion criterion, that is, effectively the number of retained variables. To our knowledge, there exists no objective method for determining the optimal inclusion criterion in the context of visualization.</p> <p>Results</p> <p>We present the projection score, which is a straightforward, intuitively appealing measure of the informativeness of a variable subset with respect to PCA visualization. This measure can be universally applied to find suitable inclusion criteria for any type of variable filtering. We apply the presented measure to find optimal variable subsets for different filtering methods in both microarray data sets and synthetic data sets. We note also that the projection score can be applied in general contexts, to compare the informativeness of any variable subsets with respect to visualization by PCA.</p> <p>Conclusions</p> <p>We conclude that the projection score provides an easily interpretable and universally applicable measure of the informativeness of a variable subset with respect to visualization by PCA, that can be used to systematically find the most interpretable PCA visualization in practical exploratory analysis.</p

    Changes in prevalence of obesity and high waist circumference over four years across European regions: the European male ageing study (EMAS).

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    Diversity in lifestyles and socioeconomic status among European populations, and recent socio-political and economic changes in transitional countries, may affect changes in adiposity. We aimed to determine whether change in the prevalence of obesity varies between the socio-politically transitional North-East European (Łódź, Poland; Szeged, Hungary; Tartu, Estonia), and the non-transitional Mediterranean (Santiago de Compostela, Spain; Florence, Italy) and North-West European (Leuven, Belgium; Malmö, Sweden; Manchester, UK) cities. This prospective observational cohort survey was performed between 2003 and 2005 at baseline and followed up between 2008 and 2010 of 3369 community-dwelling men aged 40-79 years. Main outcome measures in the present paper included waist circumference, body mass index and mid-upper arm muscle area. Baseline prevalence of waist circumference ≥ 102 cm and body mass index ≥ 30 kg/m2, respectively, were 39.0, 29.5 % in North-East European cities, 32.4, 21.9 % in Mediterranean cities, and 30.0, 20.1 % in North-West European cities. After median 4.3 years, men living in cities from transitional countries had mean gains in waist circumference (1.1 cm) and body mass index (0.2 kg/m2), which were greater than men in cities from non-transitional countries (P = 0.005). North-East European cities had greater gains in waist circumference (1.5 cm) than in Mediterranean cities (P < 0.001). Over 4.3 years, the prevalence of waist circumference ≥ 102 cm had increased by 13.1 % in North-East European cities, 5.8 % in the Mediterranean cities, 10.0 % in North-West European cities. Odds ratios (95 % confidence intervals), adjusted for lifestyle factors, for developing waist circumference ≥ 102 cm, compared with men from Mediterranean cities, were 2.3 (1.5-3.5) in North-East European cities and 1.6 (1.1-2.4) in North-West European cities, and 1.6 (1.2-2.1) in men living in cities from transitional, compared with cities from non-transitional countries. These regional differences in increased prevalence of waist circumference ≥ 102 cm were more pronounced in men aged 60-79 years than in those aged 40-59 years. Overall there was an increase in the prevalence of obesity (body mass index  ≥ 30 kg/m2) over 4.3 years (between 5.3 and 6.1 %) with no significant regional differences at any age. Mid-upper arm muscle area declined during follow-up with the greatest decline among men from North-East European cities. In conclusion, increasing waist circumference is dissociated from change in body mass index and most rapid among men living in cities from transitional North-East European countries, presumably driven by economic and socio-political changes. Information on women would also be of value and it would be of interest to relate the changes in adiposity to dietary and other behavioural habits
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