Transition Epoch Research Articles

The processes of analysis and synthesis in the transitional epoch. Toward a 100 years of the Russian revolution

The processes of analysis and synthesis in the transitional epoch. Toward a 100 years of the Russian revolution

Minimizing Interrater Variability in Staging Sleep by Use of Computer-Derived Features.

Inter-scorer variability in sleep staging of polysomnograms (PSGs) results primarily from difficulty in determining whether: (1) an electroencephalogram pattern of wakefulness spans > 15 sec in transitional epochs, (2) spindles or K complexes are present, and (3) duration of delta waves exceeds 6 sec in a 30-sec epoch. We hypothesized that providing digitally derived information about these variables to PSG scorers may reduce inter-scorer variability. Fifty-six PSGs were scored (five-stage) by two experienced technologists, (first manual, M1). Months later, the technologists edited their own scoring (second manual, M2). PSGs were then scored with an automatic system and the same two technologists and an additional experienced technologist edited them, epoch-by-epoch (Edited-Auto). This resulted in seven manual scores for each PSG. The two M2 scores were then independently modified using digitally obtained values for sleep depth and delta duration and digitally identified spindles and K complexes. Percent agreement between scorers in M2 was 78.9 ± 9.0% before modification and 96.5 ± 2.6% after. Errors of this approach were defined as a change in a manual score to a stage that was not assigned by any scorer during the seven manual scoring sessions. Total errors averaged 7.1 ± 3.7% and 6.9 ± 3.8% of epochs for scorers 1 and 2, respectively, and there was excellent agreement between the modified score and the initial manual score of each technologist. Providing digitally obtained information about sleep depth, delta duration, spindles and K complexes during manual scoring can greatly reduce interrater variability in sleep staging by eliminating the guesswork in scoring epochs with equivocal features.

New thresholds for primordial black hole formation during the QCD phase transition

Primordial Black Holes (PBHs) might have formed in the early Universe as a consequence of the collapse of density fluctuations with an amplitude above a critical value $\delta_{c}$: the formation threshold. Although for a radiation-dominated Universe $\delta_{c}$ remains constant, if the Universe experiences some dust-like phases (e.g. phase transitions) $\delta_{c}$ might decrease, improving the chances of PBH formation. We studied the evolution of $\delta_{c}$ during the QCD phase transition epoch within three different models: Bag Model (BM), Lattice Fit Model (LFM), and Crossover Model (CM). We found that the reduction on the background value of $\delta_{c}$ can be as high as $77\%$ (BM), which might imply a $\sim10^{-10}$ probability of PBHs forming at the QCD epoch.

The Soldier's Death in French Culture: a Napoleonic Case Study

The death of Marshal Jean Lannes at the Battle of Aspern-Essling in 1809 and its subsequent representation in official reports, memoirs and academic painting provides a case study in how the subject of the soldier's death remains a rich terrain for historical investigation. Studies by André Corvisier, John Keegan, Yuval Harari, Hervé Drévillon and George Mosse identify important dimensions of the topic. Analysis of the death of Lannes in the broader context of Napoleonic warfare identifies this period as a distinctive moment in the history of the soldier's death. Representations of Lannes's death reflected the Napoleonic synthesis of old regime and revolutionary ideals of military glory. Soldiers' memoirs commenting on the death of Lannes and more generally on the encounter with battlefield death reveal a mixture of matter-of-factness and deeper emotion, confirming Harari's picture of this as a transitional epoch in the soldier's experience.

A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration

Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae (SNe) and Baryon Acoustic Oscillations (BAO), providing evidence for the existence of a transition epoch at which the expansion rate changes from decelerated to accelerated. However, these results have been obtained within the framework of specific cosmological models that must be implicitly or explicitly assumed in the measurement. It is therefore crucial to obtain measurements of the accelerated expansion of the Universe independently of assumptions on cosmological models. Here we exploit the unprecedented statistics provided by the Baryon Oscillation Spectroscopic Survey (BOSS, [1-3]) Data Release 9 to provide new constraints on the Hubble parameter H(z) using the cosmic chronometers approach. We extract a sample of more than 130000 of the most massive and passively evolving galaxies, obtaining five new cosmology-independent H(z) measurements in the redshift range 0.3 < z < 0.5, with an accuracy of ∼11–16% incorporating both statistical and systematic errors. Once combined, these measurements yield a 6% accuracy constraint of H(z = 0.4293) = 91.8 ± 5.3 km/s/Mpc. The new data are crucial to provide the first cosmology-independent determination of the transition redshift at high statistical significance, measuring zt = 0.4 ± 0.1, and to significantly disfavor the null hypothesis of no transition between decelerated and accelerated expansion at 99.9% confidence level. This analysis highlights the wide potential of the cosmic chronometers approach: it permits to derive constraints on the expansion history of the Universe with results competitive with standard probes, and most importantly, being the estimates independent of the cosmological model, it can constrain cosmologies beyond—and including—the ΛCDM model.

Composite scalar dark matter from vector-like SU(2) confinement

A toy-model with [Formula: see text] dynamics confined at high scales [Formula: see text] enables to construct Dirac UV completion from the original chiral multiplets predicting a vector-like nature of their weak interactions consistent with electroweak precision tests. In this work, we investigate a potential of the lightest scalar baryon-like (T-baryon) state [Formula: see text] with mass [Formula: see text] predicted by the simplest two-flavor vector-like confinement model as a dark matter (DM) candidate. We show that two different scenarios with the T-baryon relic abundance formation before and after the electroweak (EW) phase transition epoch lead to symmetric (or mixed) and asymmetric DM, respectively. Such a DM candidate evades existing direct DM detection constraints since its vector coupling to [Formula: see text] boson absents at tree level, while one-loop gauge boson mediated contribution is shown to be vanishingly small close to the threshold. The dominating spin-independent (SI) T-baryon–nucleon scattering goes via tree-level Higgs boson exchange in the [Formula: see text]-channel. The corresponding bound on the effective T-baryon–Higgs coupling has been extracted from the recent LUX data and turns out to be consistent with naive expectations from the light technipion case [Formula: see text]. The latter provides the most stringent phenomenological constraint on strongly-coupled [Formula: see text] dynamics so far. Future prospects for direct and indirect scalar T-baryon DM searches in astrophysics as well as in collider measurements have been discussed.

Fundamental moods and Heidegger's critique of contemporary culture

Gracias a la rápida aparición de las “Obras completas” de Heidegger, podemos formarnos una imagen concreta de su desarrollo creador en la década que siguió a Ser y tiempo y que culminó en los Aportes a la filosofía escritos en 1936-38. En esta década Heidegger llego a su comprensión definitiva, a saber, ontohistórica, de la situación contemporánea de la filosofía. Su tesis fundamental es que vivimos en una época de transición: tras nosotros está la época de la metafísica que emergió del “primer comienzo” de nuestra cultura, que desde los griegos recibió un cuño filosófico. Ante nosotros, en un futuro que está apenas por intuirse, yace el “otro comienzo” para un pensamiento completamente nuevo. El pensamiento que surge del primer comienzo y sobre el cual ha reposado hasta ahora nuestra cultura, fue hecho posible por el contenerse del ser, la sustracción. Este construyó el soporte a partir del cual el ser en tanto entidad del ente se entregó al poder de la disponibilidad del pensamiento metafísico-científico. A la esencia de la sustracción le perteneció que esta se sustrajera a sí misma al pensamiento, en un ocultamiento abismal. Hoy alcanza el olvido de la sustracción determinado por ello su punto máximo, su eschaton. Dado esto podría acaecer una transformación a través de la cual el hombre se vuelva otro, a saber, capaz y dispuesto a experimentar la sustracción como sustracción, es decir, como “misterio”.

Курс истории средневековой литературы в интерпретации Вл. А. Лукова

The article describes theoretical and methodological approaches to literary studies advanced by the prominent Russian philologist and scholar of culture Vladimir Andreevich Lukov (1948–2014) while developing a course of medieval literature at the faculty of philology, Moscow State Pedagogical University. This course, as we show in the article, was influenced by the school of research started by the outstanding Russian medievalist Boris Ivanovich Purishev (1903–1989) at the Department of World Literature. Vl. A. Lukov’s important contribution to the school was in his focus on transitional epochs and transitional aesthetic phenomena. We pay attention to the original timeframe of medieval literature suggested by Vl. A. Lukov. It took the form of a “nine-century arch”, from archaic medievality (5–7th centuries CE), followed by the early Middle Ages (8–10th centuries) to High, or mature, Middle Ages (11–13th centuries). We conclude that Vladimir A. Lukov’s course on the history of medieval literature, in its syllabus, content and teaching, is of significant scholarly and practical importance for Russian medieval studies and pedagogy.

Quasi-supervised scoring of human sleep in polysomnograms using augmented input variables

The limitations of manual sleep scoring make computerized methods highly desirable. Scoring errors can arise from human rater uncertainty or inter-rater variability. Sleep scoring algorithms either come as supervised classifiers that need scored samples of each state to be trained, or as unsupervised classifiers that use heuristics or structural clues in unscored data to define states. We propose a quasi-supervised classifier that models observations in an unsupervised manner but mimics a human rater wherever training scores are available. EEG, EMG, and EOG features were extracted in 30s epochs from human-scored polysomnograms recorded from 42 healthy human subjects (18–79 years) and archived in an anonymized, publicly accessible database. Hypnograms were modified so that: 1. Some states are scored but not others; 2. Samples of all states are scored but not for transitional epochs; and 3. Two raters with 67% agreement are simulated. A framework for quasi-supervised classification was devised in which unsupervised statistical models—specifically Gaussian mixtures and hidden Markov models—are estimated from unlabeled training data, but the training samples are augmented with variables whose values depend on available scores. Classifiers were fitted to signal features incorporating partial scores, and used to predict scores for complete recordings. Performance was assessed using Cohen׳s Κ statistic. The quasi-supervised classifier performed significantly better than an unsupervised model and sometimes as well as a completely supervised model despite receiving only partial scores. The quasi-supervised algorithm addresses the need for classifiers that mimic scoring patterns of human raters while compensating for their limitations.

Evolution of dark energy–dark matter-coupled expanding universe

The acceleration of the cosmic expansion revealed by supernova observations indicates that the present universe is dominated by repulsive dark energy. It is natural that the coupling between the dark energy and the attractive gravity has to be taken into account in studying the evolution of our universe. Here we induce a dynamic equation of universe evolution based on the cosmological principal, gravity-dark energy coupling, and energy conservation. The solutions of this dynamic equation provide a specific picture of cosmic evolution, which is well compatible with current observed evolution histories of both Hubble parameter H(z) and equation of state parameter w(z) of dark energy. In this picture, the already observed universe has undergone through three epochs - the epoch of equilibrium between gravity and dark energy at cosmological redshifts z>1, the phase transition epoch at z between about 0.5 and 1, and the present acceleration epoch starting from z~0.5. The expected matter-dominated deceleration epoch has not been seen yet, which requires future deep observations to look back upon more early universe.

Impact of occultations of stellar active regions on transmission spectra

Transmission spectroscopy during planetary transits, which is based on the measurements of the variations of planet-to-star radius ratio as a function of wavelength, is a powerful technique to study the atmospheric properties of transiting planets. One of the main limitation of this technique is the effects of stellar activity, which up until now, have been taken into account only by assessing the effect of non-occulted stellar spots on the estimates of planet-to-star radius ratio. In this paper, we study, for the first time, the impact of the occultation of a stellar spot and plage on the transmission spectra of transiting exoplanets. We simulated this effect by generating a large number of transit light curves for different transiting planets, stellar spectral types, and for different wavelengths. Results of our simulations indicate that the anomalies inside the transit light curve can lead to a significant underestimation or overestimation of the planet-to-star radius ratio as a function of wavelength. At short wavelengths, the effect can reach to a difference of up to 10% in the planet-to-star radius ratio, mimicking the signature of light scattering in the planetary atmosphere. Atmospheric scattering has been proposed to interpret the increasing slopes of transmission spectra toward blue for exoplanets HD 189733b and GJ 3470b. Here we show that these signatures can be alternatively interpreted by the occultation of stellar plages. Results also suggest that the best strategy to identify and quantify the effects of stellar activities on the transmission spectrum of a planet is to perform several observations during the transit epoch at the same wavelength. This will allow for identifying the possible variations in transit depth as a function of time due to stellar activity variability.

A Blind Pre-Processor for Modulation Classification Applications in Frequency-Selective Non-Gaussian Channels

This paper presents a new preprocessing stage that allows for the reliable classification of digital amplitude-phase modulated signals in a practical scenario where: 1) the classifier has no knowledge of the timing (symbol transition epochs) of the received signal; 2) the noise added in the channel is non-Gaussian; and 3) the fading experienced by the signal is frequency selective. The proposed preprocessor, which is based on the Gibbs sampling algorithm, is used to acquire timing information and to estimate the channel state and noise distribution parameters blindly, i.e., without knowledge of the received symbol sequence and the modulation scheme used. With the obtained estimates, in a second processing stage, the signal is then classified by using an appropriate (likelihood- or feature-based) classification algorithm. To quantify the performance of the proposed preprocessor, the probability of correct classification obtained by using the preprocessor with different classification algorithms is presented. It is shown that, by using the proposed preprocessor, modulation classification algorithms can perform well compared with clairvoyant classifiers assumed to be symbol synchronous with the received signal and to have perfect knowledge of the channel state and noise distribution.

Dark Energy from graviton-mediated interactions in the QCD vacuum

Adopting the hypothesis about the exact cancellationof vacuum condensates contributions to the ground state energy inparticle physics to the leading order in graviton-mediatedinteractions, we argue that the observable cosmological constant canbe dynamically induced by an uncompensated quantum gravitycorrection to them after the QCD phase transition epoch. To startwith, we demonstrate a possible cancellation of the quark-gluoncondensate contribution to the total vacuum energy density of theUniverse at temperatures T < 100 MeV without taking into account thegraviton-mediated effects. In order to incorporate the latter, wethen calculate the leading-order quantum correction to the classicalEinstein equations due to metric fluctuations induced by thenon-perturbative vacuum fluctuations of the gluon and quark fieldsin the quasiclassical approximation. It has been demonstrated thatsuch a correction to the vacuum energy density has a formεΛ ∼ GΛQCD6, where G is thegravitational constant, and ΛQCD is the QCD scaleparameter. We analyze capabilities of this approach based on thesynthesis between quantum gravity in quasiclassical approximationand theory of non-perturbative QCD vacuum for quantitativeexplanation of the observed Dark Energy density.

G-corrected holographic dark energy model

Here we investigate the holographic dark energy model in the framework of FRW cosmology where the Newtonian gravitational constant,$G$, is varying with cosmic time. Using the complementary astronomical data which support the time dependency of $G$, the evolutionary treatment of EoS parameter and energy density of dark energy model are calculated in the presence of time variation of $G$. It has been shown that in this case, the phantom regime can be achieved at the present time. We also calculate the evolution of $G$- corrected deceleration parameter for holographic dark energy model and show that the dependency of $G$ on the comic time can influence on the transition epoch from decelerated expansion to the accelerated phase. Finally we perform the statefinder analysis for $G$- corrected holographic model and show that this model has a shorter distance from the observational point in $s-r$ plane compare with original holographic dark energy model.

The Church and Political Transition in Zimbabwe: The Inclusive Government Context

This article explores the role of the church in Zimbabwe’s political space with emphasis on the transitional epoch set in motion with the consummation of the Inclusive Government after the signing of the Global Political Agreement on 15 September 2008. Being exploratory in approach, the study preferred a qualitative research design were secondary sources were the major source of data. Departing from the view point that the church and the state are complementary in satisfying human needs, the research established that the church is replete with political activists who are partaking in key political processes envisaged under the transitional phase and the enormity of their participation vary depending on the national issue at hand. More clearly, the church’s association with the political parties in the government has been mostly that of a horse-rider relationship where politicians use the church to score cheap political points.

Transit timing variations in WASP-10b induced by stellar activity

The hot-Jupiter WASP-10b was reported by Maciejewski et al. (2011a,b) to show transit timing variations (TTV) with an amplitude of ~ 3.5 minutes. These authors proposed that the observed TTVs were caused by a 0.1 MJup perturbing companion with an orbital period of ~ 5.23 d, and hence, close to the outer 5:3 mean motion resonance with WASP-10b. To test this scenario, we present eight new transit light curves of WASP-10b obtained with the Faulkes Telescope North and the Liverpool Telescope. The new light curves, together with 22 previously published ones, were modelled with a Markov-Chain Monte-Carlo transit fitting code. (...) Our homogeneously derived transit times do not support the previous claimed TTV signal, which was strongly dependent on 2 previously published transits that have been incorrectly normalised. Nevertheless, a linear ephemeris is not a statistically good fit to the transit times of WASP-10b. We show that the observed transit time variations are due to spot occultation features or systematics. We discuss and exemplify the effects of occultation spot features in the measured transit times and show that despite spot occultation during egress and ingress being difficult to distinguish in the transit light curves, they have a significant effect in the measured transit times. We conclude that if we account for spot features, the transit times of WASP-10 are consistent with a linear ephemeris with the exception of one transit (epoch 143) which is a partial transit. Therefore, there is currently no evidence for the existence of a companion to WASP-10b. Our results support the lack of TTVs of hot-Jupiters reported for the Kepler sample.

PLANETARY CANDIDATES OBSERVED BY KEPLER . III. ANALYSIS OF THE FIRST 16 MONTHS OF DATA

New transiting planet candidates are identified in sixteen months (May 2009 - September 2010) of data from the Kepler spacecraft. Nearly five thousand periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1,091 viable new planet candidates, bringing the total count up to over 2,300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multi-quarter photo-center offsets derived from difference image analysis which identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the new candidates. Ephemerides (transit epoch, T_0, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (Rp/R*), reduced semi-major axis (d/R*), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (197% for candidates smaller than 2Re compared to 52% for candidates larger than 2Re) and those at longer orbital periods (123% for candidates outside of 50-day orbits versus 85% for candidates inside of 50-day orbits). The gains are larger than expected from increasing the observing window from thirteen months (Quarter 1-- Quarter 5) to sixteen months (Quarter 1 -- Quarter 6). This demonstrates the benefit of continued development of pipeline analysis software. The fraction of all host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the Habitable Zone are forthcoming if, indeed, such planets are abundant.

Spielraum im Diesseits. (Un-)Verfügbarkeit der Zeit und des Ichs

Abstract The article questions the changes which took place in the perception of time and of the self during an epoch of historical transition. Using the example of early modern prose romances (among others Fortunatus, Hug Schapler, Der Goldfaden) it is demonstrated that the category of the linearity of (a life-) time acquires a new meaning and that simultaneously the perception of time starts to detach itself from the cyclical rhythm of nature (and from the liturgical year). In this way, the conceptions of the Verfügbarkeit of time and of life are shifted. The article shows the extent to which the prose romance thematised in different ways the relations which are fraught with tension between the Unverfügbarkeit of a lifetime and the cyclical dimensions of time; in addition it also demonstrates the role which is thus played by self-awareness.

Holographic dark energy with time varying parameter c 2

We consider the holographic dark energy model in which the model parameter $c^2$ evolves slowly with time. First we calculate the evolution of EoS parameter as well as the deceleration parameter in this generalized version of holographic dark energy (GHDE). Depending on the parameter $c^2$, the phantom regime can be achieved earlier or later compare with original version of holographic dark energy. The evolution of energy density of GHDE model is investigated in terms of parameter $c^2$. We also show that the time-dependency of $c^2$ can effect on the transition epoch from decelerated phase to accelerated expansion. Finally, we perform the statefinder diagnostic for GHDE model and show that the evolutionary trajectories of the model in $s-r$ plane are strongly depend on the parameter $c^2$.

Cosmological Evolution of Supermassive Black Holes: Mass Functions and Spins

AbstractWe derive the mass function of supermassive black holes (SMBHs) over the redshift range 0 &gt; z ≲ 2, using the latest deep luminosity and mass functions of field galaxies. Applying this mass function, combined with the bolometric luminosity function of active galactic nuclei (AGNs), into the the continuity equation of SMBH number density, we explicitly obtain the mass-dependent cosmological evolution of the radiative efficiency for accretion. We suggest that the accretion history of SMBHs and their spins evolve in two distinct regimes: an early phase of prolonged accretion, plausibly driven by major mergers, during which the black hole spins up, then switching to a period of random, episodic accretion, governed by minor mergers and internal secular processes, during which the hole spins down. The transition epoch depends on mass, mirroring other evidence for “cosmic downsizing” in the AGN population.