Search results for "first"
showing 10 items of 1149 documents
XMM-Newton First-Light Observations of the Hickson Galaxy Group 16
2000
This paper presents the XMM-Newton first-light observations of the Hickson-16 compact group of galaxies. Groups are possibly the oldest large-scale structures in the Universe, pre-dating clusters of galaxies, and are highly evolved. This group of small galaxies, at a redshift of 0.0132 (or 80 Mpc) is exceptional in the having the highest concentration of starburst or AGN activity in the nearby Universe. So it is a veritable laboratory for the study of the relationship between galaxy interactions and nuclear activity. Previous optical emission line studies indicated a strong ionising continuum in the galaxies, but its origin, whether from starbursts, or AGN, was unclear. Combined imaging and…
Use of site symmetry in supercell models of defective crystals: Polarons in CeO2
2017
The authors thank R. Merkle and G. W. Watson for stimulating discussions. E. K. also acknowledges partial financial support from the Russian Science Foundation for the study of charged defects under the project 14-43-00052. A. C. also acknowledges financial support from the University of Latvia Foundation (Arnis Riekstins's "MikroTik" donation). E. K. and D. G. express their gratitude to the High Performance Computer Centre in Stuttgart (HLRS, project DEFTD 12939) for the provided computer facilities whereas R. A. E. thanks the St. Petersburg State University Computer Center for assistance in high-performance calculations.
Time-Independent Canonical Perturbation Theory
2001
First we consider the perturbation calculation only to first order, limiting ourselves to only one degree of freedom. Furthermore, the system is to be conservative, ∂ H∕∂ t = 0, and periodic in both the unperturbed and perturbed case. In addition to periodicity, we shall require the Hamilton–Jacobi equation to be separable for the unperturbed situation. The unperturbed problem H0(J0) which is described by the action-angle variables J0 and w0 will be assumed to be solved. Thus we have, for the unperturbed frequency: $$\displaystyle{ \nu _{0} = \frac{\partial H_{0}} {\partial J_{0}} }$$ (10.1) and $$\displaystyle{ w_{0} =\nu _{0}t +\beta _{0}\;. }$$ (10.2) Then the new Hamiltonian reads, up t…
Association of Exposure to Ambient Air Pollution With Thyroid Function During Pregnancy
2019
Key Points Question Is exposure to ambient air pollution in the first trimester associated with thyroid function throughout pregnancy? Findings Among 9931 pregnant women in 4 European cohorts and 1 US cohort, an increase of 5 μg/m3 in exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less was associated with 20% higher odds of hypothyroxinemia. Meaning The findings of this study raise the possibility that exposure to particulate matter might disrupt thyroid function in pregnant women.
Cytogenetic analyses of culture failures by comparative genomic hybridisation (CGH)–Re-evaluation of chromosome aberration rates in early spontaneous…
2001
Comparative genomic hybridisation (CGH) represents an alternative molecular-cytogenetic technique capable of detecting chromosomal imbalances by reverse fluorescence in situ hybridisation. As the technique uses genomic DNA for assessment it does not rely on metaphase chromosomes in the test material and thus circumvents technical problems associated with tissue culturing. In the present study, we applied CGH to identify chromosome anomalies in 60 spontaneous abortions of the first trimester, that had failed to grow in culture. In 57 out of 60 cases CGH analyses were successful. The overall aneuploidy rate detected was 72%. Trisomy was the predominant chromosome anomaly accounting for 68.0% …
Más allá del acero: Otros metales y sus usos en la arquitectura del siglo XXI
2009
[ES] El protagonismo que ostentan los metales como compuestos básicos para el desenvolvimiento cotidiano de la vida humana resulta evidente e irrefutable. Del mismo modo que una mayoría de las actividades diarias que realizamos serían imposibles sin el apoyo que nos brinda el metal, un amplio porcentaje de la arquitectura de la última centuria también hace descansar sus fundamentos en la solidez de una estructura metálica. Más allá del hierro como predecesor y del acero como digno sucesor, la constructiva recurre asimismo con asiduidad a otros metales para conformar con ellos la imagen final del edificio, redundando en ésta componentes tanto técnicos como expresivos de los que son responsab…
Systems Thinking Research in the Twenty-First Century
2017
In this opinion article, the author aims to depict the state of systems thinking research through the lens of my own personal experience. His point of view is that of a relatively young scholar who has the privilege to be involved in the international systems thinking community in many ways. Indeed, in 2012 he established, with other colleagues, an academic society named Business Systems Laboratory (BSLab), which has rapidly become an important society for research into the application of systems thinking to society, business and organizations. Through his activity of organization of conferences and his editorial activity at the journals associated with BSLab (and recently as Editor-in-Chie…
Willingness to Communicate in a Foreign Language: Evidence from Those Who Approach and Those Who Avoid L2 Communication
2014
It is still unclear why some learners are willing to communicate in a foreign language while others are disinclined to do so. One of the most promising paths of inquiry in this respect is the study of willingness to communicate (WTC), focusing on the volitional process of initiating, maintaining, and terminating communication. That is the reason why the main purpose of this paper is to investigate the testimonials of Polish students with persistently low or high L2 WTC scores obtained during their 3-year secondary grammar school experience. The qualitative results of the study appear to demonstrate that, independently from the individual’s general predilections towards communication in the …
Historicizing Divergence: A Comparative Analysis of the Revolutionary Crises in Russia and Finland
2016
Beginning 1917, Russia and Finland both experienced revolutionary situations, the seizure of power by radical political groups, and civil wars. However, the ultimate outcomes of the revolutionary crises in the two countries turned out to be different: the Russian Bolsheviks won the struggle for power whereas the Finnish Red Guard suffered a defeat. Why did the radical socialists win in Russia but lose in Finland? This chapter argues that the Russian revolutionaries benefited from the existence of two coalition alliances that had not fully materialized in Finland: the workers–soldiers’ alliance, which was critical for the radicals’ seizure of power, and the workers–peasants’ alliance, which …
BODY GROWTH AND POLYCYTHAEMIA IN HYPOXIC ALBINO RATS OF FIRST AND SECOND GENERATION
1990
SUMMARY 1. In our study we followed the growth rate and the haematologic changes occurring in albino rats of Wistar strain when living in a hypoxic environment. Two generations of hypoxic rats were observed for changes in their erythrocytes (RBC), haematocrit (Hct) and haemoglobin (Hb): the first generation (H1) and the second generation (H2). A few hours after birth, the H1 rats were placed and raised in a normobaric hypoxic environment (10% O2 in N2). The H2 rats were born and raised in the environment previously described. The control group had a normoxic environment. The H1 and H2 rats had inferior growth rates in respect to their controls, but H2 were found to have a larger growth rate…