872 research outputs found

    A probabilistic multi-objective approach for FACTS devices allocation with different levels of wind penetration under uncertainties and load correlation

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    This study presents a probabilistic multi-objective optimization approach to obtain the optimal locations and sizes of static var compensator (SVC) and thyristor-controlled series capacitor (TCSC) in a power transmission network with large level of wind generation. In this study, the uncertainties of the wind power generation and correlated load demand are considered. The uncertainties are modeled in this work using the points estimation method (PEM). The optimization problem is solved using the Multi-objective particle swarm optimization (MOPSO) algorithm to find the best position and rating of the flexible AC transmission system (FACTS) devices. The objective of the problem is to maximize the system loadability while minimizing the power losses and FACTS devices installation cost. Additionally, a technique based on fuzzy decision-making approach is employed to extract one of the Pareto optimal solutions as the best compromise one. The proposed approach is applied on the modified IEEE 30-bus system. The numerical results evince the effectiveness of the proposed approach and shows the economic benefits that can be achieved when considering the FACTS controller

    BREXIT: Psychometric Profiling the Political Salubrious Through Machine Learning: Predicting personality traits of Boris Johnson through Twitter political text

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    Whilst the CIA have been using psychometric profiling for decades, Cambridge Analytica showed that people\u27s psychological characteristics can be accurately predicted from their digital footprints, such as their Facebook or Twitter accounts. To exploit this form of psychological assessment from digital footprints, we propose machine learning methods for assessing political personality from Twitter. We have extracted the tweet content of Prime Minster Boris Johnson’s Twitter account and built three predictive personality models based on his Twitter political content. We use a Multi-Layer Perceptron Neural network, a Naive Bayes multinomial model and a Support Machine Vector model to predict the OCEAN model which consists of the Big Five personality factors from a sample of 3355 political tweets. The approach vectorizes political tweets, then it learns word vector representations as embeddings from spaCy that are then used to feed a supervised learner classifier. We demonstrate the effectiveness of the approach by measuring the quality of the predictions for each trait per model from a classification algorithm. Our findings show that all three models compute the personality trait “Openness” with the Support Machine Vector model achieving the highest accuracy. “Extraversion” achieved the second highest accuracy personality score by the Multi-Layer Perceptron neural network and Support Machine Vector model

    Repeated observations on the Salmonella culture status of midwest U.S. herds

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    Mesenteric lymph nodes were collected from pigs from 115 Midwest U.S. swine herds at slaughter on two occasions separated by 6-9 months. These herds were sampled up to three additional times during a three-year period, with 30 herds sampled five times. Thirty pigs were sampled at each collection. Herds were categorized positive if one or more samples revealed Salmonella spp. While culture status at collection one was associated with the second sampling collection (p \u3c 0.01), the association was only moderate in strength (OR = 2.6). Herds with three consecutive positive tests (9 of 38) were all positive on sample four. Prevalence estimates were weakly or not correlated between samplings. In conclusion, Salmonella culture status of these swine herds was weakly predictive of future culture results. Accurate description of Salmonella status based on bacterial culture appears to require repeated or ongoing testing

    Role of the domestic dog as a reservoir host of Leishmania donovani in eastern Sudan

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    <p>Abstract</p> <p>Background</p> <p>The study aims to determine the role of domestic dogs in transmission of visceral leishmaniasis in eastern Sudan. A cross-sectional survey was conducted in 10 villages along the River Rahad in eastern Sudan to elucidate the role of domestic dogs (<it>Canis familiaris</it>, Linnaeus, 1758) as a reservoir host of <it>Leishmania donovani</it>. In this study, 87 dogs were screened for infection by <it>Leishmania donovani</it>. Blood and lymph node samples were taken from 87 and 33 dogs respectively and subsequently screened by the Polymerase Chain Reaction (PCR) and Direct Agglutination Test (DAT) test. Additional lymph node smears were processed for microscopy and parasite culture. Host preference of the visceral leishmaniasis (VL) vector in the area, <it>Phlebotomus orientalis</it>, and other sandflies for the Nile rat (<it>Arvicanthis niloticus</it>, É. Geoffrey, 1803), the genet (<it>Genetta genetta</it>, Linnaeus, 1758), the mongoose (<it>Herpeistes ichneumon</it>, Linnaeus, 1758), and the domestic dog were determined by counting numbers of sand flies attracted to CDC traps that were baited by these animals.</p> <p>Results</p> <p>DAT on blood samples detected anti-<it>Leishmania </it>antibodies in 6 samples (6.9%). Two out of 87 (2.3%) blood samples tested were PCR positive, giving an amplification product of 560 bp. The two positive samples by PCR were also positive by DAT. However, none of the 33 lymph nodes aspirates were <it>Leishmania </it>positive when screened by microscopy, culture and genus-specific PCR. The dog-baited trap significantly attracted the highest number of <it>P. orientalis </it>and sand fly species (P < 0.001). This was followed by the Egyptian mongoose baited trap and less frequently by the genet baited trap.</p> <p>Conclusion</p> <p>It is concluded that the results obtained from host attraction studies indicate that dog is more attractive for <it>P. orientalis </it>than Egyptian mongoose, common genet and Nile rat.</p

    Synthesis of some nucleosides derivatives from L- rhamnose with expected biological activity

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    Practical procedures for production of variously blocked compounds from L-rhamnose have been developed. These compounds are highly useful as indirect ÎČ-L-rhamnosyl donors. This approach represents a new method for the synthesis of aromatic nucleoside analogues and the synthesis of (3S, 4S, 5S, 6R) 3, 4, 5-triacetoxy-2-methyl-7,9-diaza-1-oxa-spiro [4,5]decane-10-one-8-thione (7)

    The Frequencies of Different Inborn Errors of Metabolism in Adult Metabolic Centres: Report from the SSIEM Adult Metabolic Physicians Group

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    There are few centres which specialise in the care of adults with inborn errors of metabolism (IEM). To anticipate facilities and staffing needed at these centres, it is of interest to know the distribution of the different disorders

    Observation of mesoscopic crystalline structures in a two-dimensional Rydberg gas

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    The ability to control and tune interactions in ultracold atomic gases has paved the way towards the realization of new phases of matter. Whereas experiments have so far achieved a high degree of control over short-ranged interactions, the realization of long-range interactions would open up a whole new realm of many-body physics and has become a central focus of research. Rydberg atoms are very well-suited to achieve this goal, as the van der Waals forces between them are many orders of magnitude larger than for ground state atoms. Consequently, the mere laser excitation of ultracold gases can cause strongly correlated many-body states to emerge directly when atoms are transferred to Rydberg states. A key example are quantum crystals, composed of coherent superpositions of different spatially ordered configurations of collective excitations. Here we report on the direct measurement of strong correlations in a laser excited two-dimensional atomic Mott insulator using high-resolution, in-situ Rydberg atom imaging. The observations reveal the emergence of spatially ordered excitation patterns in the high-density components of the prepared many-body state. They have random orientation, but well defined geometry, forming mesoscopic crystals of collective excitations delocalised throughout the gas. Our experiment demonstrates the potential of Rydberg gases to realise exotic phases of matter, thereby laying the basis for quantum simulations of long-range interacting quantum magnets.Comment: 10 pages, 7 figure

    Management der PrimÀren CiliÀren Dyskinesie

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    Die PrimĂ€re CiliĂ€re Dyskinesie (PCD, MIM 242650) ist eine seltene hereditĂ€re Multisystemerkrankung mit klinisch heterogenem PhĂ€notyp. Leitsymptom ist eine chronische Sekretretention der oberen und unteren Atemwege, welche durch die Dysfunktion motiler respiratorischer Zilien entsteht. In der Folge kommt es zur Ausbildung von Bronchiektasen, hĂ€ufig zu einer Infektion durch Pseudomonas aeruginosa sowie einer abnehmenden Lungenfunktion bis hin zum Lungenversagen. Bislang gibt es kaum evidenzbasierte Therapieempfehlungen, da randomisierte Langzeitstudien zur Behandlung der PCD fehlten. In diesem Jahr wurden die Daten einer ersten placebokontrollierten Medikamentenstudie bei PCD veröffentlicht. AnlĂ€sslich dieses Meilensteins im Management der PCD wurde der vorliegende Übersichtsartikel als Konsens von Patientenvertretern sowie Klinikern, die langjĂ€hrige Erfahrung in der Behandlung der PCD haben, verfasst. Diese Arbeit bietet eine Zusammenfassung aktuell eingesetzter Behandlungsverfahren, die ĂŒberwiegend auf persönlichen Erfahrungen und Expertenmeinungen beruhen oder von anderen Atemwegserkrankungen wie der Cystischen Fibrose (CF), COPD oder Bronchiektasen-Erkrankung abgeleitet werden. Da es derzeit keine kurative Therapie fĂŒr PCD gibt, stehen symptomatische Maßnahmen wie die regelmĂ€ĂŸige Reinigung der Atemwege und die Behandlung von rezidivierenden Atemwegsinfektionen im Fokus. Nicht respiratorische Manifestationen werden organspezifisch behandelt. Um neben der ersten Medikamentenstudie mehr evidenzbasiertes Wissen zu generieren, werden weitere Projekte etabliert, u. a. ein internationales PCD-Register. HierĂŒber wird Patienten der Zugang zu klinischen und wissenschaftlichen Studien erleichtert und die Vernetzung behandelnder Zentren gefördert. Des Weiteren können Erkenntnisse ĂŒber eine Genotyp-spezifische Erkrankungsschwere erlangt werden, um folglich die therapeutische Versorgung der Patienten zu verbessern und somit zu individualisieren. = Primary Ciliary Dyskinesia (PCD, MIM 242650) is a rare, hereditary multiorgan disease characterized by malfunction of motile cilia. Hallmark symptom is a chronic airway infection due to mucostasis leading to irreversible lung damage that may progress to respiratory failure. There is no cure for this genetic disease and evidence-based treatment is limited. Until recently, there were no randomized controlled trials performed in PCD, but this year, data of the first placebo-controlled trial on pharmacotherapy in PCD were published. This cornerstone in the management of PCD was decisive for reviewing currently used treatment strategies. This article is a consensus of patient representatives and clinicians, which are highly experienced in care of PCD-patients and provides an overview of the management of PCD. Treatments are mainly based on expert opinions, personal experiences, or are deduced from other lung diseases, notably cystic fibrosis (CF), COPD or bronchiectasis. Most strategies focus on routine airway clearance and treatment of recurrent respiratory tract infections. Non-respiratory symptoms are treated organ specific. To generate further evidence-based knowledge, other projects are under way, e. g. the International PCD-Registry. Participating in patient registries facilitates access to clinical and research studies and strengthens networks between centers. In addition, knowledge of genotype-specific course of the disease will offer the opportunity to further improve and individualize patient care

    Direct observation of incommensurate magnetism in Hubbard chains

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    The interplay between magnetism and doping is at the origin of exotic strongly correlated electronic phases and can lead to novel forms of magnetic ordering. One example is the emergence of incommensurate spin-density waves with a wave vector that does not match the reciprocal lattice. In one dimension this effect is a hallmark of Luttinger liquid theory, which also describes the low energy physics of the Hubbard model. Here we use a quantum simulator based on ultracold fermions in an optical lattice to directly observe such incommensurate spin correlations in doped and spin-imbalanced Hubbard chains using fully spin and density resolved quantum gas microscopy. Doping is found to induce a linear change of the spin-density wave vector in excellent agreement with Luttinger theory predictions. For non-zero polarization we observe a decrease of the wave vector with magnetization as expected from the Heisenberg model in a magnetic field. We trace the microscopic origin of these incommensurate correlations to holes, doublons and excess spins which act as delocalized domain walls for the antiferromagnetic order. Finally, when inducing interchain coupling we observe fundamentally different spin correlations around doublons indicating the formation of a magnetic polaron
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