5,190 research outputs found

    Echinopla cherapunjiensis sp. n. (Hymenoptera, Formicidae) from India

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    Echinopla cherapunjiensis Bharti et Gul, sp. n. is described from India. This represents the second species of genus reported in India, with only Echinopla lineata senilis Mayr, 1862 described earlier from Nicobar Islands. The species distinctly differs from all other known species of this genus by the following combination of characters: globose shape of head, presence of seven teeth on petiolar scale, flat dorsum of mesosoma with promesonotal and mesometanotal sutures obsolete, whole body surface (dorsum) rough due to sinuous sculpture, deep excavations and spiky elevations on head and mesosoma and excavations on gaster.Echinopla cherapunjiensis Bharti et Gul, sp. n. описан из Индии. Это второй представитель рода, обнаруженный в Индии, вместе с видом Echinopla lineata senilis Mayr, 1862, описанный ранее с Никобарских островов. Этот вид четко отличается от всех других известных видов этого рода рядом признаков: шаровидной головой, наличием семи зубцов на петиолярном сегменте, плоской брюшной частью с промезонотальным и мезометанотальным рудиментарным швом, шероховатой дорсальной поверхностью тела благодаря волнистой скульптуре, глубокими выемкам и шиповидными выпуклостями на голове и мезосоме, а также выемками на брюшке

    Septal perforators stemming from a very long left main coronary artery

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    We report a case of a very long left main coronary artery, 58mm,  with septal perforators before bifurcation. The coronary arteries were seen clear of plaques. To the best of our knowledge this case is a very rare case because of the existance of the first and the second septal perforator arteries originating from a very long left main coronary artery

    Forage yield of berseem (Trifolium alaxandrium) as affected by phosphorus and potassium fertilization

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    This research was conducted with the aim to quantify the effect of phosphorus and potassium fertilization on forage yield of berseem (Trifolium alaxandrium). The experiment was carried out at the Research Farm of Khyber Pakhtunkhwa, Agricultural University Peshawar, Pakistan during the cropping season of 2004 to 2005. Randomized complete block design (RCBD) having four replications was used for the experiment. Significant differences were found among the treatments for number of branches per plant, fresh forage yield and dry forage yield. The highest number of branches per plant (9.15), fresh forage yield (6077 kg ha-1) and dry forage yield (156.83 kg ha-1) were recorded in plots with 60 kg P ha-1 x 30 kg K ha-1 treatments, while the lowest values of 6.93, 5430 kg ha-1 and 153.80 kg ha-1 for branches per plant, fresh forage yield and dry forage yield, respectively were recorded in the plots with no fertilizer (control). Emergence (m-2) and plant height of berseem were non-significantly affected by phosphorus and potassium fertilization. So, it was concluded that berseem showed better performance in terms of higher forage yield under 60 kg P ha-1 x 30 kg K ha-1 levels in Peshawar valley.Key words: Phosphorus, potassium, forage yield, berseem

    Proximity induced superconductivity in indium gallium arsenide quantum wells

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    We report on the experimental observation of the proximity induced superconductivity in an indium gallium arsenide (In0.75Ga0.25As) quantum well. The Josephson junction was fabricated by several photo-lithographic processes on an InGaAs heterojunction and Niobium (Nb) was used as superconducting electrodes. Owing to the Andreev reflections and Andreev bound states at the Nb-In0.75Ga0.25As quantum well-Nb interfaces, the subharmonic energy gap structures (SGS) are observed at the differential conductance (dI/dV) versus voltage (V) plots when the applied source-drain bias voltages satisfy the expression VSD = 2Δ/ne. The dI/dV as a function of applied magnetic field B shows a maximum at zero B which decreases by increasing B. When decreasing B to below ±0.4 T, a hysteresis and shift of the conductance maxima close to B = 0 T are observed. Our results help to pave the way to the development of integrated coherent quantum circuitry.Authors acknowledge financial support from EPSRC grant numbers EP/M009505/1 and EP/J017671/1. K. Delfanazari is grateful to Dr. H. Asai for helpful discussions

    On-Chip Andreev Devices: Hard Superconducting Gap and Quantum Transport in Ballistic Nb–In0.75Ga0.25AsQuantum-Well–Nb Josephson Junctions

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    A superconducting hard gap in hybrid superconductor–semiconductor devices has been found to be necessary to access topological superconductivity that hosts Majorana modes (non-Abelian excitation). This requires the formation of homogeneous and barrier-free interfaces between the superconductor and semiconductor. Here, a new platform is reported for topological superconductivity based on hybrid Nb–In0.75_{0.75}Ga0.25_{0.25}As-quantum-well–Nb that results in hard superconducting gap detection in symmetric, planar, and ballistic Josephson junctions. It is shown that with careful etching, sputtered Nb films can make high-quality and transparent contacts to the In0.75_{0.75}Ga0.25_{0.25}As quantum well, and the differential resistance and critical current measurements of these devices are discussed as a function of temperature and magnetic field. It is demonstrated that proximity-induced superconductivity in the In0.75_{0.75}Ga0.25_{0.25}As-quantum-well 2D electron gas results in the detection of a hard gap in four out of seven junctions on a chip with critical current values of up to 0.2 µA and transmission probabilities of >0.96. The results, together with the large g-factor and Rashba spin–orbit coupling in In0.75_{0.75}Ga0.25_{0.25}As quantum wells, which indeed can be tuned by the indium composition, suggest that the Nb–In0.75_{0.75}Ga0.25_{0.25}As–Nb system can be an excellent candidate to achieve topological phase and to realize hybrid topological superconducting devices.Authors acknowledge financial support from EPSRC grant numbers EP/M009505/1 and EP/J017671/1

    Zero-Magnetic Field Fractional Quantum States

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    Since the discovery of the fractional quantum Hall effect in 1982 there has been considerable theoretical discussion on the possibility of fractional quantization of conductance in the absence of Landau levels formed by a quantizing magnetic field. Although various situations have been theoretically envisaged, particularly lattice models in which band flattening resembles Landau levels, the predicted fractions have never been observed. In this Letter, we show that odd and even denominator fractions can be observed, and manipulated, in the absence of a quantizing magnetic field, when a low-density electron system in a GaAs based one-dimensional quantum wire is allowed to relax in the second dimension. It is suggested that such a relaxation results in formation of a zigzag array of electrons with ring paths which establish a cyclic current and a resultant lowering of energy. The behavior has been observed for both symmetric and asymmetric confinement but increasing the asymmetry of the confinement potential, to result in a flattening of confinement, enhances the appearance of new fractional states. We find that an in-plane magnetic field induces new even denominator fractions possibly indicative of electron pairing. The new quantum states described here have implications both for the physics of low dimensional electron systems and also for quantum technologies. This work will enable further development of structures which are designed to electrostatically manipulate the electrons for the formation of particular configurations. In turn, this could result in a designer tailoring of fractional states to amplify particular properties of importance in future quantum computation

    Zero-magnetic field fractional quantum states

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    Since the discovery of the fractional quantum Hall effect in 1982 there has been considerable theoretical discussion on the possibility of fractional quantization of conductance in the absence of Landau levels formed by a quantizing magnetic field. Although various situations have been theoretically envisaged, particularly lattice models in which band flattening resembles Landau levels, the predicted fractions have never been observed. In this Letter, we show that odd and even denominator fractions can be observed, and manipulated, in the absence of a quantizing magnetic field, when a low-density electron system in a GaAs based one-dimensional quantum wire is allowed to relax in the second dimension. It is suggested that such a relaxation results in formation of a zigzag array of electrons with ring paths which establish a cyclic current and a resultant lowering of energy. The behavior has been observed for both symmetric and asymmetric confinement but increasing the asymmetry of the confinement potential, to result in a flattening of confinement, enhances the appearance of new fractional states. We find that an in-plane magnetic field induces new even denominator fractions possibly indicative of electron pairing. The new quantum states described here have implications both for the physics of low dimensional electron systems and also for quantum technologies. This work will enable further development of structures which are designed to electrostatically manipulate the electrons for the formation of particular configurations. In turn, this could result in a designer tailoring of fractional states to amplify particular properties of importance in future quantum computation

    Mining predicate rules without minimum support threshold

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    Association rule mining (ARM) is used for discovering frequent itemsets for interesting relationships of associative and correlative behaviors within the data. This gives new insights of great value, both commercial and academic. The traditional ARM techniques discover interesting association rules based on a predefined minimum support threshold. However, there is no known standard of an exact definition of minimum support and providing an inappropriate minimum support value may result in missing important rules. In addition, most of the rules discovered by these traditional ARM techniques refer to already known knowledge. To address these limitations of the minimum support threshold in ARM techniques, this study proposes an algorithm to mine interesting association rules without minimum support using predicate logic and a property of a proposed interestingness measure (g measure). The algorithm scans the database and uses g measure’s property to search for interesting combinations. The selected combinations are mapped to pseudo-implications and inference rules of logic are used on the pseudo-implications to produce and validate the predicate rules. Experimental results of the proposed technique show better performance against state-of-the-art classification techniques, and reliable predicate rules are discovered based on the reliability differences of the presence and absence of the rule’s consequence

    Predicting Flare in Patients With Rheumatoid Arthritis in Biologic Induced Remission, on Tapering, and on Stable Therapy

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    Objective The tapering of biologic disease-modifying antirheumatic drug (b-DMARD) therapy for patients with rheumatoid arthritis (RA) in stable remission is frequently undertaken, but specific guidance on how to successfully taper is lacking. The objective of this study is to identify predictors of flare in patients in stable b-DMARD–induced clinical remission, who did or did not follow structured b-DMARD tapering. Methods Patients with RA receiving b-DMARD treatment who had achieved sustained remission according to a Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP) <2.6 for ≥6 months were offered tapering. Clinical, ultrasound (US) (total power Doppler [PD]/grayscale abnormalities), CD4+ T cell subsets, and patient-reported outcomes (PROs) were collected at inclusion. The primary endpoint was the occurrence of flare (loss of DAS28-CRP remission) over 12 months. Logistic regression analyses identified predictors of flare. Dichotomization into high/low-risk groups was based on 80% specificity using the area under the receiving operator curve (AUROC). Results Of 63 patients choosing tapering, 23 (37%) flared compared with 12 of 60 (20%) on stable treatment (P = 0.043). All patients who flared regained remission upon reinstating treatment. In the tapering group, flare was associated with lower regulatory T cell (Treg) (P < 0.0001) and higher CRP levels (P < 0.0001), erythrocyte sedimentation rate (P < 0.035), and inflammation-related cells (IRCs) (P = 0.054); stepwise modeling selected Tregs (odds ratio [OR] = 0.350, P = 0.004), IRCs (OR = 1.871, P = 0.007), and CRP level (OR = 1.577, P = 0.004) with 81.7% accuracy and AUROC = 0.890. In the continued therapy group, modeling retained the tender joint count, total PD, and visual analog scale pain score, with 82.1% accuracy and AUROC = 0.899. Most patients in the study were considered low risk of flare (80 of 123 patients [65%]). Only 5 of 37 (13.5%) of the low-risk patients who tapered flared, which was notable compared with the continued therapy group (20% flare). Conclusion Flare on tapering b-DMARDs was predicted by lower Tregs and elevated inflammation biomarkers (IRCs/CRP level); flare on continued b-DMARDs was associated with raised pain parameters and US inflammation. Knowledge of these biomarkers should improve outcomes by targeted selection for tapering, and by increased monitoring of those on continued therapy predicted to flare
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