5,991 research outputs found
Analysis of close encounters with Ganymede and Callisto using a genetic n-body algorithm
In this work we describe a genetic algorithm which is used in order to study
orbits of minor bodies in the frames of close encounters. We find that the
algorithm in combination with standard orbital numerical integrators can be
used as a good proxy for finding typical orbits of minor bodies in close
encounters with planets and even their moons, saving a lot of computational
time compared to long-term orbital numerical integrations. Here, we study close
encounters of Centaurs with Callisto and Ganymede in particular. We also
perform n-body numerical simulations for comparison. We find typical impact
velocities to be between and for
Ganymede and between and for
Callisto.Comment: 18 pages, 3 figure
DaMiRseq—an R/Bioconductor package for data mining of RNA-Seq data: normalization, feature selection and classification
Abstract
Summary
RNA-Seq is becoming the technique of choice for high-throughput transcriptome profiling, which, besides class comparison for differential expression, promises to be an effective and powerful tool for biomarker discovery. However, a systematic analysis of high-dimensional genomic data is a demanding task for such a purpose. DaMiRseq offers an organized, flexible and convenient framework to remove noise and bias, select the most informative features and perform accurate classification.
Availability and implementation
DaMiRseq is developed for the R environment (R ≥ 3.4) and is released under GPL (≥2) License. The package runs on Windows, Linux and Macintosh operating systems and is freely available to non-commercial users at the Bioconductor open-source, open-development software project repository (https://bioconductor.org/packages/DaMiRseq/). In compliance with Bioconductor standards, the authors ensure stable package maintenance through software and documentation updates.
Supplementary information
Supplementary data are available at Bioinformatics online
Multi-objective optimization control of plug-in electric vehicles in low voltage distribution networks.
Indium selenide: An insight into electronic band structure and surface excitations
We have investigated the electronic response of single crystals of indium selenide by means of angle-resolved photoemission spectroscopy, electron energy loss spectroscopy and density functional theory. The loss spectrum of indium selenide shows the direct free exciton at similar to 1.3 eV and several other peaks, which do not exhibit dispersion with the momentum. The joint analysis of the experimental band structure and the density of states indicates that spectral features in the loss function are strictly related to single-particle transitions. These excitations cannot be considered as fully coherent plasmons and they are damped even in the optical limit, i.e. for small momenta. The comparison of the calculated symmetry-projected density of states with electron energy loss spectra enables the assignment of the spectral features to transitions between specific electronic states. Furthermore, the effects of ambient gases on the band structure and on the loss function have been probed
Matrix biorthogonal polynomials on the unit circle and non-Abelian Ablowitz-Ladik hierarchy
Adler and van Moerbeke \cite{AVM} described a reduction of 2D-Toda hierarchy
called Toeplitz lattice. This hierarchy turns out to be equivalent to the one
originally described by Ablowitz and Ladik \cite{AL} using semidiscrete
zero-curvature equations. In this paper we obtain the original semidiscrete
zero-curvature equations starting directly from the Toeplitz lattice and we
generalize these computations to the matrix case. This generalization lead us
to the semidiscrete zero-curvature equations for the non-abelian (or
multicomponent) version of Ablowitz-Ladik equations \cite{GI}. In this way we
extend the link between biorthogonal polynomials on the unit circle and
Ablowitz-Ladik hierarchy to the matrix case.Comment: 23 pages, accepted on publication on J. Phys. A., electronic link:
http://stacks.iop.org/1751-8121/42/36521
Предварительная оценка энергоэффективности зданий в условиях резко континентального климата
Construction of energy-efficient buildings becomes a top priority for many countries. Yet certain obstacles in achieving internal environment comfort standards remain in regions with extreme continental climate. In addition to engineering and economic challenges, there exist design process issues since design data should closely correspond with resulting performance of the building. This paper focuses on accurate energy demand estimation during design stage. Two types of buildings designed for Ural-Siberian region of Russia and for Kazakhstan are examined: detached and medium-rise apartment buildings. Most influential factors are taken into consideration and general recommendations on improving energy efficiency using effective combination of structural and engineering solutions are given. Adaptation of design procedure in terms of extreme continental climate made by means of simplified but precise Passive House planning tool is demonstrated.Строительство энергоэффективных зданий является приоритетным направлением для многих стран. Однако в регионах с суровым климатом часто возникают проблемы достижения нормативных показателей комфорта внутренней среды. В идеале проектные значения потребностей в электроэнергии на отопление и кондиционирование здания должны точно соответствовать итоговым показателям. В этой статье рассматриваются методики точного прогнозирования энергопотребления на стадии проектирования. Исследовано два типа зданий, проектируемых для Урало-Сибирского региона России и Казахстана: индивидуальный дом и многоквартирный дом средней этажности. Даны рекомендации по снижению энергопотребления зданий путем эффективного сочетания конструктивных и инженерных решений. Показан учет основных факторов, влияющих на энергетический баланс зданий. На примере Пакета проектирования пассивного дома 2007 приведен пример адаптации упрощенной, но достаточно точной методики расчета к резко континентальным климатическим условиям
Effect of the polymer structure on the viscoelastic and interfacial healing behaviour of poly(urea-urethane) networks containing aromatic disulphides
The macroscopic interfacial healing behaviour in a series of urea-urethane networks as function of the hydrogen bonds and disulphides content is presented. The polymers were prepared with different crosslinking densities but with the same amount of dynamic covalent bonds (disulphide linkages). Tensile and fracture measurements were adopted to evaluate the degree of recovery of the mechanical properties after damage. Healing kinetics and healing efficiencies were quantitatively determined as a function of network composition, healing temperature and contact time. Finally, the recovery of mechanical properties was correlated with the viscoelastic response of the networks through rheological measurements and time-temperature superposition principle (TTS). The application of the TTS approach on both fracture healing and DMTA and subsequent mathematical descriptive model led to a better understanding of the influence of polymer architecture and that of the amount of reversible groups on the healing process
A systematic review of childhood maltreatment and resting state functional connectivity
Resting-state functional connectivity (rsFC) has the potential to shed light on how childhood abuse and neglect relates to negative psychiatric outcomes. However, a comprehensive review of the impact of childhood maltreatment on the brain's resting state functional organization has not yet been undertaken. We systematically searched rsFC studies in children and youth exposed to maltreatment. Nineteen studies (total n = 3079) met our inclusion criteria. Two consistent findings were observed. Childhood maltreatment was linked to reduced connectivity between the anterior insula and dorsal anterior cingulate cortex, and with widespread heightened amygdala connectivity with key structures in the salience, default mode, and prefrontal regulatory networks. Other brain regions showing altered connectivity included the ventral anterior cingulate cortex, dorsolateral prefrontal cortex, and hippocampus. These patterns of altered functional connectivity associated with maltreatment exposure were independent of symptoms, yet comparable to those seen in individuals with overt clinical disorder. Summative findings indicate that rsFC alterations associated with maltreatment experience are related to poor cognitive and social functioning and are prognostic of future symptoms. In conclusion, maltreatment is associated with altered rsFC in emotional reactivity, regulation, learning, and salience detection brain circuits. This indicates patterns of recalibration of putative mechanisms implicated in maladaptive developmental outcomes
Distinctive physiological muscle synergy patterns define the Box and Block Task execution as revealed by electromyographic features
Stroke survivors experience muscular pattern alterations of the upper limb that decrease their ability to perform daily-living activities. The Box and Block test (BBT) is widely used to assess the unilateral manual dexterity. Although BBT provides insights into functional performance, it returns limited information about the mechanisms contributing to the impaired movement. This study aims at exploring the BBT by means of muscle synergies analysis during the execution of BBT in a sample of 12 healthy participants with their dominant and non-dominant upper limb. Results revealed that: (i) the BBT can be described by 1 or 2 synergies; the number of synergies (ii) does not differ between dominant and non-dominant sides and (iii) varies considering each phase of the task; (iv) the transfer phase requires more synergies. Clinical Relevance— This preliminary study characterizes muscular synergies during the BBT task in order to establish normative patterns that could assist in understanding the neuromuscular demands and support future evaluations of stroke deficit
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