1,912 research outputs found
Isoperiodic deformations of the acoustic operator and periodic solutions of the Harry Dym equation
We consider the problem of describing the possible spectra of an acoustic
operator with a periodic finite-gap density. We construct flows on the moduli
space of algebraic Riemann surfaces that preserve the periods of the
corresponding operator. By a suitable extension of the phase space, these
equations can be written with quadratic irrationalities.Comment: 15 page
DNA double-strand breaks induced by high NaCl occur predominantly in gene deserts
High concentration of NaCl increases DNA breaks both in cell culture and in vivo. The breaks remain elevated as long as NaCl concentration remains high and are rapidly repaired when the concentration is lowered. The exact nature of the breaks, and their location, has not been entirely clear, and it has not been evident how cells survive, replicate, and maintain genome integrity in environments like the renal inner medulla in which cells are constantly exposed to high NaCl concentration. Repair of the breaks after NaCl is reduced is accompanied by formation of foci containing phosphorylated H2AX (Ξ³H2AX), which occurs around DNA double-strand breaks and contributes to their repair. Here, we confirm by specific comet assay and pulsed-field electrophoresis that cells adapted to high NaCl have increased levels of double-strand breaks. Importantly, Ξ³H2AX foci that occur during repair of the breaks are nonrandomly distributed in the mouse genome. By chromatin immunoprecipitation using anti-Ξ³H2AX antibody, followed by massive parallel sequencing (ChIP-Seq), we find that during repair of double-strand breaks induced by high NaCl, Ξ³H2AX is predominantly localized to regions of the genome devoid of genes (βgene desertsβ), indicating that the high NaCl-induced double-strand breaks are located there. Localization to gene deserts helps explain why the DNA breaks are less harmful than are the random breaks induced by genotoxic agents such as UV radiation, ionizing radiation, and oxidants. We propose that the universal presence of NaCl around animal cells has directly influenced the evolution of the structure of their genomes
Quantitative magnetotail characteristics of different magnetospheric states
Quantitative relationships allowing one to compute the lobe magnetic field, flaring angle and tail radius, and to evaluate magnetic flux based on solar wind/IMF parameters and spacecraft position are obtained for the middle magnetotail, <i>X</i>=(β15,β35)<i>R<sub>E</sub></i>, using 3.5 years of simultaneous Geotail and Wind spacecraft observations. For the first time it was done separately for different states of magnetotail including the substorm onset (SO) epoch, the steady magnetospheric convection (SMC) and quiet periods (Q). In the explored distance range the magnetotail parameters appeared to be similar (within the error bar) for Q and SMC states, whereas at SO their values are considerably larger. In particular, the tail radius is larger by 1β3 <i>R<sub>E</sub></i> at substorm onset than during Q and SMC states, for which the radius value is close to previous magnetopause model values. The calculated lobe magnetic flux value at substorm onset is ~1GWb, exceeding that at Q (SMC) states by ~50%. The model magnetic flux values at substorm onset and SMC show little dependence on the solar wind dynamic pressure and distance in the tail, so the magnetic flux value can serve as an important discriminator of the state of the middle magnetotail.<br><br> <b>Key words.</b> Magnetospheric physics (solar windmagnetosphere- interactions, magnetotail, storms and substorms
ΠΡΡΠ΅ΡΠ½Π°Ρ ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΡ ΠΏΡΠΈΠΊΡΠ΅ΠΏΠΈΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠ³Π°Π½Π° Lamellodiscus (Monogenea: Diplectanidae)
ΠΡΠΈ ΠΏΠΎΠΌΠΎΡΠΈ ΠΎΠΊΡΠ°ΡΠΊΠΈ ΠΌΡΡΡ ΡΠ»ΡΠΎΡΠ΅ΡΡΠ΅Π½ΡΠ½ΠΎ ΠΌΠ΅ΡΠ΅Π½ΡΠΌ ΡΠ°Π»Π»ΠΎΠΈΠ΄ΠΈΠ½ΠΎΠΌ ΠΈ ΠΊΠΎΠ½ΡΠΎΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ ΠΈΠ·ΡΡΠ΅Π½Π° ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΡ ΠΌΡΡΠΊΡΠ»Π°ΡΡΡΡ Π³Π°ΠΏΡΠΎΡΠ° Ρ Π΄Π²ΡΡ
Π²ΠΈΠ΄ΠΎΠ² ΠΌΠΎΠ½ΠΎΠ³Π΅Π½Π΅ΠΉ ΠΈΠ· ΡΠ΅ΠΌΠ΅ΠΉΡΡΠ²Π° Diplectanidae, ΠΎΡΠ½ΠΎΡΡΡΠΈΡ
ΡΡ ΠΊ ΡΠΎΠ΄Ρ Lamellodiscus (L. fraternus ΠΈ L. elegans), ΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ Π΅Π΅ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ Ρ ΠΌΡΡΠΊΡΠ»Π°ΡΡΡΠΎΠΉ Π³Π°ΠΏΡΠΎΡΠ° Ρ ΡΠ°Π½Π΅Π΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Π½ΡΡ
ΠΏΡΠ΅Π΄ΡΡΠ°Π²ΠΈΡΠ΅Π»Π΅ΠΉ Π΄ΠΈΠΏΠ»Π΅ΠΊΡΠ°Π½ΠΈΠ΄ ΠΈΠ· ΡΠΎΠ΄Π° Diplectanum. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΠΎΠΊΠ°Π·ΡΠ²Π°Π΅Ρ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠ΅ΠΉ ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΡΡΠΊΡΠ»Π°ΡΡΡΡ Π³Π°ΠΏΡΠΎΡΠ° Π² ΡΠΈΡΡΠ΅ΠΌΠ°ΡΠΈΠΊΠ΅ Π΄ΠΈΠΏΠ»Π΅ΠΊΡΠ°Π½ΠΈΠ΄
βSiena Caseβ: the Political Development of the Siena of the Renaissance in Historiography of the Second Half of XX-XXI Centuries
The basic approaches to the study of the political development and government of Siena, one of the Italian republics of the Renaissance, are examined. The works of Western, especially Italian, historians of the second half of the XX - beginning of the XXI centuries are analyzed. The novelty of the study is that the author summarizes the results of studying the problem, shows the evolution of approaches to its solution, introduces the reader to modern views on it. An urgent question about the specifics of the Renaissance state by the example of the formation of Siena statehood in the second half of the XIV - first half of the XVI centuries has been raised. Based on a study of the works touching upon this problem, the author shows that during the study period the issue of the features of Sienaβs political and state development was considered from different perspectives and underwent evolution from the problem of the decline of Siena to the problems of autonomy of the Siena state within the βMedici stateβ. Analysis of Western historiography of this period leads the author to agree with the conclusions of Italian scientists that the formation of a system of βpartiesβ and coalition governments in Siena determines not only the relatively late formation of Signoria Petrucci, but also the specifics of Sienaβs political and state development a kind of historical alternative to the Florentine signoria
Protein Tracking by CNN-Based Candidate Pruning and Two-Step Linking with Bayesian Network
Protein trafficking plays a vital role in understanding many biological
processes and disease. Automated tracking of protein
vesicles is challenging due to their erratic behaviour, changing
appearance, and visual clutter. In this paper we present
a novel tracking approach which utilizes a two-step linking
process that exploits a probabilistic graphical model to predict
tracklet linkage. The vesicles are initially detected with
help of a candidate selection process, where the candidates
are identified by a multi-scale spot enhancing filter. Subsequently,
these candidates are pruned and selected by a light
weight convolutional neural network. At the linking stage,
the tracklets are formed based on the distance and the detection
assignment which is implemented via combinatorial
optimization algorithm. Each tracklet is described by a number
of parameters used to evaluate the probability of tracklets
connection by the inference over the Bayesian network. The
tracking results are presented for confocal fluorescence microscopy
data of protein trafficking in epithelial cells. The
proposed method achieves a root mean square error (RMSE)
of 1.39 for the vesicle localisation and of 0.7 representing
the degree of track matching with ground truth. The presented
method is also evaluated against the state-of-the-art βTrackmateβ
framework
Introduction to Dynamic Linear Models for Time Series Analysis
Dynamic linear models (DLM) offer a very generic framework to analyse time
series data. Many classical time series models can be formulated as DLMs,
including ARMA models and standard multiple linear regression models. The
models can be seen as general regression models where the coefficients can vary
in time. In addition, they allow for a state space representation and a
formulation as hierarchical statistical models, which in turn is the key for
efficient estimation by Kalman formulas and by Markov chain Monte Carlo (MCMC)
methods. A dynamic linear model can handle non-stationary processes, missing
values and non-uniform sampling as well as observations with varying
accuracies. This chapter gives an introduction to DLM and shows how to build
various useful models for analysing trends and other sources of variability in
geodetic time series.Comment: A chapter submitted to a book with a proposed title: Geodetic Time
Series Analysis and Applications, editors. J.-P. Montillet and M. Bo
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