An Efficient Algorithm For Chinese Postman Walk on Bi-directed de Bruijn Graphs

Sequence assembly from short reads is an important problem in biology. It is known that solving the sequence assembly problem exactly on a bi-directed de Bruijn graph or a string graph is intractable. However finding a Shortest Double stranded DNA string (SDDNA) containing all the k-long words in the reads seems to be a good heuristic to get close to the original genome. This problem is equivalent to finding a cyclic Chinese Postman (CP) walk on the underlying un-weighted bi-directed de Bruijn graph built from the reads. The Chinese Postman walk Problem (CPP) is solved by reducing it to a general bi-directed flow on this graph which runs in O(|E|2 log2(|V |)) time. In this paper we show that the cyclic CPP on bi-directed graphs can be solved without reducing it to bi-directed flow. We present a ?(p(|V | + |E|) log(|V |) + (dmaxp)3) time algorithm to solve the cyclic CPP on a weighted bi-directed de Bruijn graph, where p = max{|{v|din(v) - dout(v) > 0}|, |{v|din(v) - dout(v) < 0}|} and dmax = max{|din(v) - dout(v)}. Our algorithm performs asymptotically better than the bidirected flow algorithm when the number of imbalanced nodes p is much less than the nodes in the bi-directed graph. From our experimental results on various datasets, we have noticed that the value of p/|V | lies between 0.08% and 0.13% with 95% probability

Radiation of electrons in Weibel-generated fields: a general case

Weibel instability turns out to be the a ubiquitous phenomenon in High-Energy Density environments, ranging from astrophysical sources, e.g., gamma-ray bursts, to laboratory experiments involving laser-produced plasmas. Relativistic particles (electrons) radiate in the Weibel-produced magnetic fields in the Jitter regime. Conventionally, in this regime, the particle deflections are considered to be smaller than the relativistic beaming angle of 1/$\gamma$ ($\gamma$ being the Lorentz factor of an emitting particle) and the particle distribution is assumed to be isotropic. This is a relatively idealized situation as far as lab experiments are concerned. We relax the assumption of the isotropy of radiating particle distribution and present the extension of the jitter theory amenable for comparisons with experimental data.Comment: Proceedings of International Conference on HEDP/HEDLA-0

Particle Acceleration in Pulsar Wind Nebulae: PIC modelling

We discuss the role of particle-in-cell (PIC) simulations in unveiling the origin of the emitting particles in PWNe. After describing the basics of the PIC technique, we summarize its implications for the quiescent and the flaring emission of the Crab Nebula, as a prototype of PWNe. A consensus seems to be emerging that, in addition to the standard scenario of particle acceleration via the Fermi process at the termination shock of the pulsar wind, magnetic reconnection in the wind, at the termination shock and in the Nebula plays a major role in powering the multi-wavelength signatures of PWNe.Comment: 32 pages, 16 figures, to appear in the book "Modelling Nebulae" edited by D. Torres for Springer, based on the invited contributions to the workshop held in Sant Cugat (Barcelona), June 14-17, 201

Eigenmodes and growth rates of relativistic current filamentation instability in a collisional plasma

I theoretically found eigenmodes and growth rates of relativistic current filamentation instability in collisional regimes, deriving a generalized dispersion relation from self-consistent beam-Maxwell equations. For symmetrically counterstreaming, fully relativistic electron currents, the collisional coupling between electrons and ions creates the unstable modes of growing oscillation and wave, which stand out for long-wavelength perturbations. In the stronger collisional regime, the growing oscillatory mode tends to be dominant for all wavelengths. In the collisionless limit, those modes vanish, while maintaining another purely growing mode that exactly coincides with a standard relativistic Weibel mode. It is also shown that the effects of electron-electron collisions and thermal spread lower the growth rate of the relativistic Weibel instability. The present mechanisms of filamentation dynamics are essential for transport of homogeneous electron beam produced by the interaction of high power laser pulses with plasma.Comment: 44 pages, 12 figures. Accepted for publication in Phys. Rev.

Relativistic Laser-Matter Interaction and Relativistic Laboratory Astrophysics

The paper is devoted to the prospects of using the laser radiation interaction with plasmas in the laboratory relativistic astrophysics context. We discuss the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas and emphasize a similarity between the laser and astrophysical plasmas in the ultrarelativistic energy limit. In particular, we address basic mechanisms of the charged particle acceleration, the collisionless shock wave and magnetic reconnection and vortex dynamics properties relevant to the problem of ultrarelativistic particle acceleration.Comment: 58 pages, 19 figure

Sleep Disorders in Post-COVID Syndrome: A Psychiatric or Neurological Problem?

The coronavirus pandemic that began in 2019 continues. COVID-19 adversely affects human health not only in the acute, but also in the long-term period of the disease: in a large percentage of cases, health is not fully restored after long periods, requires medical intervention, and is often difficult to correct. Researchers noted during the first wave of the pandemic in 2020 that about 10–20% of patients did not fully recover by three weeks from disease onset and the possible duration of the recovery period remains insufficiently clear, as do the reasons for differences in course during this period. Prolonged recovery after viral infection is not a feature exclusive to COVID-19, which does not facilitate the management of patients with post-COVID syndrome (PCS). The mental health impact of COVID-19 is significant, with at least 30% of recovered patients likely to have symptoms of anxiety and/or depression after the acute phase has passed. Since the onset of COVID-19, there has been an increase in sleep disorders by 42%, with every third COVID-19 survivor reporting sleep complaints. In PCS, this condition is referred to as coronasomnia. The success of therapy for this condition depends on identifying and correcting patients’ mental disorders, as anxiety and depression are often accompanied by sleep disorders this results in a bidirectional interaction between mental disorders and sleep quality. This article presents data on the anti-anxiety drugs Noofen and Adaptol, which help to correct the manifestations of PCS with sleep disorders

Sleep disorders in post-COVID syndrome - a problem of psychiatry or neurology? [Rasstroistva sna pri postkovidnom sindrome — problema psikhiatrii ili nevrologii?]

The pandemic of coronavirus infection, which has begun in 2019, has not ended to this day. COVID-19 adversely affects human health not only in the acute period of the disease, but also in the long-run: in a large percentage of cases, recovery takes very long, patients require and often have problems returning to their baseline. During the first wave of the pandemic in 2020, researchers noted that about 10-20% of patients didn't fully recover three weeks after the onset of the disease. It is still not clear how long the recovery period can last, and what are the reasons of different time course of the recovery. Long-term recovery after a viral infection is a non-unique feature of COVID-19, which does not facilitate the management of patients with post-COVID syndrome. The impact on mental health after COVID-19 is significant, and at least 30% of those, who have been ill, may have symptoms of anxiety and/or depression after the acute phase of the disease. Since the emergence of the SARS-CoV-2 virus, there has been an increase in somnological disorders by 42%, while every third COVID-19 patient reports altered sleep patterns. In post-COVID-19 syndrome, this condition is referred to as Coronasomnia (COVID-somnia). The success of therapy of this condition depends on reporting and treating mental disorders in patients, as anxiety and depression are often accompanied by sleep disorders, that is, there is a bidirectional influence of mental disorders on the quality of sleep. The article provides data on two anti-anxiety drugs (noofen and adaptol) that help to treat the manifestations of post-COVID syndrome accompanied by sleep disorders.Пандемия коронавирусной инфекции, начавшаяся в 2019 г., по сей день не завершилась. COVID-19 пагубно влияет на здоровье человека не только в острый, но и в отдаленный период заболевания: в большом проценте случаев здоровье полностью не восстанавливается длительное время, требует медицинского вмешательства, зачастую трудно поддается коррекции. Исследователи еще во время первой волны пандемии в 2020 г. отметили, что около 10—20% пациентов не полностью выздоровели через 3 нед от начала заболевания, до сих пор недостаточно ясно, как долго может длиться период выздоровления, и причины разного течения этого периода. Длительное восстановление после перенесенной вирусной инфекции не является исключительной особенностью COVID-19, что не облегчает курацию пациентов с постковидным синдромом (ПКС). Влияние на психическое здоровье перенесенного COVID-19 значительно, по крайней мере, у 30% переболевших могут быть симптомы тревоги и/или депрессии после минования острой фазы. С момента появления COVID-19 отмечено увеличение сомнологических расстройств на 42%, при этом каждый 3-й переболевший COVID-19 отмечает жалобы со стороны сна. При ПКС такое состояние обозначают как Coronasomnia (коронасомния). Успех терапии этого состояния зависит от учета и коррекции психических расстройств у пациента, так как тревога и депрессия часто сопровождаются нарушениями сна, существует двунаправленное влияние психических расстройств на качество сна. В статье приводятся данные о противотревожных препаратах Ноофен и Адаптол, помогающих корректировать проявления ПКС с расстройствами сна