3D Geographical routing in wireless sensor networks

In this paper, we present a novel 3D geographical routing algorithm (3DGR) that makes use of the position information to route packets from sources to destinations with high path quality and reliability. The locality and high scalability of this algorithm make it suitable for wireless sensor networks. It provides high adaptability to changes in topology and recovery of link failures which increases its reliability. We also incorporate the battery-aware energy efficient schemes to increase the overall lifetime of the network. To reduce latency, a method of keeping a small record of recent paths is used. We also show that location errors still result in good performance of our algorithm while the same assumptions might yield to bad performance or even complete failures in others. Simulation results show that the power consumption and delay using 3DGR are close to optimal obtainable based on full knowledge of the network

Do Investors Care About Noise Trader Risk?

International audienceThe link between investor sentiment and asset valuation is at the center of a long-running debate in behavioral finance. Using a new composite sentiment indicator, we show that the conventional risk does not explain the abnormal returns of portfolios most sensitive to the sentiment factor. Our result supports the existence of a sentiment risk valued by financial markets. We also find that the firms more impacted by the sentiment risk correspond to difficult-to-arbitrage and hard-to-value stocks, e.g. small stocks, growth stocks, young stocks, unprofitable stocks, lower dividend-paying stocks, intangible stocks and high volatility stocks

Self organization of sensor networks for energy-efficient border coverage

Networking together hundreds or thousands of cheap sensor nodes allows users to accurately monitor a remote environment by intelligently combining the data from the individual nodes. As sensor nodes are typically battery operated, it is important to efficiently use the limited energy of the nodes to extend the lifetime of the wireless sensor network (WSN). One of the fundamental issues in WSNs is the coverage problem. In this paper, the border coverage problem in WSNs is rigorously analyzed. Most existing results related to the coverage problem in wireless sensor networks focused on planar networks; however, three dimensional (3D) modeling of the sensor network would reflect more accurately real-life situations. Unlike previous works in this area, we provide distributed algorithms that allow the selection and activation of an optimal border cover for both 2D and 3D regions of interest. We also provide self-healing algorithms as an optimization to our border coverage algorithms which allow the sensor network to adaptively reconfigure and repair itself in order to improve its own performance. Border coverage is crucial for optimizing sensor placement for intrusion detection and a number of other practical applications

Entrepreneurial refugees and the city: brief encounters in Beirut

Lebanon is hosting more than 1 million Syrian refugees. For a country of its size, and a population of around 4 million, this influx of Syrians into Lebanon has exposed many of its already established ailments. A prevailing perception is that Syrians are establishing businesses and competing with the Lebanese, leading to violent reactions on the part of host communities. In this article, we seek to debunk the reductionist framing of ‘the Syrian refugee’ as a burden, and showcase the economic contribution that some Syrian entrepreneurs have been making to urban neighbourhoods. While entrepreneurs certainly represent a minority of the refugees in Lebanon, we argue that, rather than being competition, Syrian entrepreneurs are complementary to Lebanese businesses in urban areas, and that Syrian businesses are enriching spatial practices in the city. As such, we claim their experiences are significant to document as they can inform useful policy interventions that can render Syrian self-employment an opportunity for local economic development in cities and towns

De l'étude fondamentale des intéractions en solution à la conception de matériaux hybrides à base de polyoxométallates

Herein, we report the use of 1H DOSY NMR methodology to track the interaction between aninorganic multireceptor capsule, referring to the well-defined spherical Keplerate-type{Mo132} ion and a series of organic cation (including tetraalklylammonium). The obtainedresults reveal a strong dependence of the self-diffusion coefficient of the cationic guestsbalancing from the solvated to the plugging situations. Quantitative analysis of the data basedon two-site exchange regime, involving the 20 independent {Mo9O9} receptors of the capsule,allowed determining the stability constants associated to the plugging process of the pores.Surprisingly, the affinity of the capsule for a series of cationic guests increases continuouslywith its apolar character. Such observations evidence that the major factor dictating selectivityin the trapping process is mainly the so-called “hydrophobic effect”.Further investigation focused on the design of Keplerate-based materials where theammonium cations was replaced by imidazolium cations. The obtained materials werecharacterized in the solid state by FT-IR, TGA and elemental analysis. These materials exhibitliquid crystalline phase as evidenced by polarized optical microscopy and DSC, however,folding of the alkyl chain prohibit the formation of well organized mesophase. Finally, thisstrategy was extended to cyclic [Na2K2{Mo4O4S4(H2O)3(OH)2}2(P8W48O184)]32- which wasisolated as DODA or imidazolium salt. Solid state NMR evidence the well organization of thesolid. The obtained materials exhibit smectic A liquid crystalline phase and packed ashexagonal lamellar arrangement in the solid state.La première partie de ce mémoire concerne l’étude en solution de systèmes à base de POMset de cations organiques de polarité/taille variables. Ainsi, l’étude des interactions entre unanion Keplerate noté {Mo132} et une large série de cations organiques (composée d’ions alkylammonium AA) a nécessité la mise en place d’une méthodologie spécifique utilisant la RMNDOSY de 1H. La méthode s’est révélée particulièrement efficace et a permis non seulement demettre clairement en évidence l’existence d’interactions anion-cation fortes mais aussil’extraction des constantes d’association à partir d’un traitement quantitatif des données. Cetteétude révèle que le facteur qui domine le processus d’association anion-cation résulte d’un« effet hydrophobe » directement lié au caractère apolaire du cation organique et polaire dusolvant. Les constantes de stabilité sont en accord avec des interactions plutôt fortes. ParParailleurs, une expérience spécifique a permis de titrer les 20 pores présents à la surface de l’ionKeplérate, montrant ainsi la spécificité du processus d’association.La seconde partie de ce mémoire concerne la conception de matériaux à base de Képlerate enjouant sur la nature des cations imidazolium qui lui sont associés. Les phases solides ont étécaractérisées par spectrométrie infrarouge, analyse élémentaire, EDX et analysethermogravimétrique. Ces études montrent que dans certaines conditions, ces systèmes seaffichent un comportement type cristal liquide.La troisième partie s’intéresse spécifiquement aux interactions ionique et/ou van der Waals àl’origine de phénomènes de structuration. L’anion cyclique[Na2K2{Mo4O4S4(H2O)3(OH)2}2(P8W48O184)]32- ( noted 1) a été isolé à l’état solide sous laforme de sels de DODA (dioctadécyl-diméthyl-ammonium) ou d’imidazolium. L’analysestructurale de ces phases par RMN MAS de 1H, 13C et 31P montre sans ambigüitél’organisation des chaines alkyles. Ces résultats croisés avec la microscopie optique polarisée,l’analyse thermique différentielle et la diffraction des rayons X aux petits angles montrentclairement la formation de phases mésomorphes lamellaires dont l’espacement estdirectement lié à la longueur des chaines alkyles

Telemedicine in the Era of COVID-19 and Beyond: A new horizon

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The Role of Gabapentin in The Treatment of Tinnitus

Tinnitus is considered one of the most common symptoms that urge the patient to visit the ENT doctors(otolaryngologists) it is also difficult to recognize exactly the main reason of tinnitus, which create a problem for the doctor  and for the patient as well. A research has been conducted on " 50" patients by using Gabapentin for treating tinnitus in patients visited  private clinics and the ENT clinic in BaniasNathional Hospital during the period from 2012 to 2015. Patients were given 200 mg Gabapentin orally every day,  after ensuring their tolerance of Gabapentin, the dose was increased by average 200 mg every two weeks until it reached 1600 mg. The dose 1600mg was divided into two doses in the morning and in the evening. The treatment lasted for six months. We observed, that Gabapentin had positive effects for treating tinnitus to the patients who didn't have acoustic trauma or long term noise. Treatment with Gabapentin was more effective on young  people, and on who  had a short term tinnitus . Therefore,we conclude that the use of Gabapentin in treating tinnitus is advisable because of its major inhibitory neurotransmitter and its wide distribution in thecentral auditory pathway. دور الغابابنتين Gabapentin في معالجة الطنين يعتبر الطنين أحد أشيع الأعراض التي يأتي بها المرضى الى طبيب الاذن والانف والحنجرةوالتي غالبا يصعب معرفة السبب المؤدي لها  وهذا يشكل مصدر قلق للمريض والطبيب . تم اجراء البحث باستخدام عقار دوائي هو الغابابنتين في معالجة الطنين عند 50 مريضا من مراجعي العيادة الخاصة والعيادة الاذنية في الهيئة العامة لمشفى الشهيد اياد احمد ابراهيم ( بانياس الوطني سابقا) خلال الفترة 2012 م – 2015 م.تم اعطاء الغابابنتين بجرعة 200 ملغ يوميا فمويا, وبعد التأكد من التحمل الدوائي تم زيادة الجرعة بشكل تدريجي بمعدل 200ملغ كل اسبوعين, وبجرعة قصوي 1600 ملغ يومياً مقسمة على جرعتين صباحية ومسائية, واستمرت المعالجة لمدة ستة اشهر . لوحظ وجود تأثيرات ايجابية في معالجة الطنين عند المرضى الذين لم يتعرضوا للرضوض الصوتية أو التأثير المديد للضجيج , وكانت الاستجابة للمعالجة افضل في الاعمار المبكرة وايضا كلما كانت الفترة الزمنية للطنين قصيرة, ولذا ينصح باستخدام الغابابنتين كدواء مثبط للنواقل العصبية في الطرق السمعية المركزية في معالجة الطنين

Las tensiones sobre la ayuda tras la explosión del puerto de Beirut en 2020

Las tensiones pueden intensificarse en contextos de crisis superpuestas: los actores humanitarios deben reconocer los diferentes tipos de tensión resultantes de la distribución de la ayuda y responder en consecuencia