Tracking granules at the Sun's surface and reconstructing velocity fields. II. Error analysis

The determination of horizontal velocity fields at the solar surface is crucial to understanding the dynamics and magnetism of the convection zone of the sun. These measurements can be done by tracking granules. Tracking granules from ground-based observations, however, suffers from the Earth's atmospheric turbulence, which induces image distortion. The focus of this paper is to evaluate the influence of this noise on the maps of velocity fields. We use the coherent structure tracking algorithm developed recently and apply it to two independent series of images that contain the same solar signal. We first show that a k-\omega filtering of the times series of images is highly recommended as a pre-processing to decrease the noise, while, in contrast, using destretching should be avoided. We also demonstrate that the lifetime of granules has a strong influence on the error bars of velocities and that a threshold on the lifetime should be imposed to minimize errors. Finally, although solar flow patterns are easily recognizable and image quality is very good, it turns out that a time sampling of two images every 21 s is not frequent enough, since image distortion still pollutes velocity fields at a 30% level on the 2500 km scale, i.e. the scale on which granules start to behave like passive scalars. The coherent structure tracking algorithm is a useful tool for noise control on the measurement of surface horizontal solar velocity fields when at least two independent series are available.Comment: in press in Astronomy and Astrophysics, 9 page

Assessing Reconstruction: Did the South Undergo Revolutionary Change?

With the end of the Civil War, came a number of unanswered questions Reconstruction would attempt to answer for the South. While the South underwent economic, political and social changes for a short period, old traditions continued to persist resulting in racist sentiment

Overview Chapter 7: The rising importance of migrants for childbearing in Europe

This contribution looks at the influence of immigration on childbearing trends in the countries of Western, Northern and Southern Europe, which have received relatively large numbers of immigrants during the last decades. It analyses the contribution of migrants to the total number of births and compares fertility rates of migrant women with the fertility rates of native women, pointing out huge diversity between migrant groups. It also discusses the evidence regarding the progressive ‘assimilation’ in migrants’ fertility to the local fertility patterns and analyses the net impact of migrants on period fertility rates. This review reveals that migrant women typically retain substantially higher levels of period fertility than the ‘native’ populations, but this difference typically diminishes over time and with the duration of their stay in a country. Immigrants contribute substantially to the total number of births and their share of total births has increased in the last decade, exceeding in some countries one fifth of the recorded live births. However, the ‘net effect’ of the higher fertility of migrants on the period total fertility of particular countries remains relatively small, typically between 0.05 and 0.10 in absolute terms.childbearing, Europe, fertility, migration

Fertility in Austria: An Overview

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Characteristic Dependence of Umbral Dots on their Magnetic Structure

Umbral dots (UDs) were observed in a stable sunspot in NOAA 10944 by the Hinode Solar Optical Telescope on 2007 March 1. The observation program consisted of blue continuum images and spectropolarimetric profiles of Fe I 630 nm line. An automatic detection algorithm for UDs was applied to the 2-hour continuous blue continuum images, and using the obtained data, the lifetime, size, and proper motion of UDs were calculated. The magnetic structure of the sunspot was derived through the inversion of the spectropolarimetric profiles. We calculated the correlations between UD's parameters (size, lifetime, occurrence rate, proper motion) and magnetic fields (field strength, inclination, azimuth), and obtained the following results: (1) Both the lifetime and size of UDs are almost constant regardless of the magnetic field strength at their emergence site. (2) The speed of UDs increases as the field inclination angle at their emergence site gets larger. (3) The direction of movement of UDs is nearly parallel to the direction of the horizontal component of magnetic field in the region with strongly inclined field, while UDs in the region with weakly inclined field show virtually no proper motion. Our results describe the basic properties of magnetoconvection in sunspots. We will discuss our results in comparison to recent MHD simulations by Schussler & Vogler (2006) and Rempel et al. (2009).Comment: 22 pages, 10 figures, accepted for publication in Ap

A Proposal for a Tourism Regionalization of Poland Based on the Highest Levels of Tourism in a Region

The paper presents a brief review of twenty proposals for tourism regionalization of either a part of or the whole of Poland (or attempts to delimit the most attractive areas in terms of leisure), formulated between 1938 and 2012. It also analyses selected definitions of tourism regions and discusses the indicators which are proposed for the delimitation of tourism regions. Moreover, the paper attempts to indicate areas with the highest levels of tourism, in part modelled on Maria Mileska (1908-1988). It includes academic (precise) criteria for the designation of tourism regions. Some researchers’ comment that Mileska’s work is (partially) outmoded not so much from the methods employed as in the number of tourism regions and the areas covered. This should be regarded as understandable given that this regionalization was formulated at the beginning of the 1960s. Another important issue raised is the most recent tourism regionalization of Poland as prepared by Durydiwka

Overview Chapter 4: Changing family and partnership behaviour

Following the era of the ‘golden age of marriage’ and the baby boom in the 1950s and 1960s, marriage has declined in importance, and its role as the main institution on which family relations are built has been eroded across Europe. Union formation most often takes place without a marriage. Family and living arrangements are currently heterogeneous across Europe, but all countries seem to be making the same shifts: towards fewer people living together as a couple, especially in marriage; an increased number of unmarried couples; more children born outside marriage; and fewer children living with their two parents. The relationship between these changing living arrangements, especially the decline of marriage, on the one hand, and the overall level of fertility, on the other, is not straightforward. In most countries, marriage rates and fertility declined simultaneously. However, the aggregate relationship between marriage and fertility indices has moved from negative (fewer marriages imply fewer births) to positive (fewer marriages imply more births). Thus, the decline of marriage, which is a part of the second demographic transition (see Overview Chapter 6), cannot be considered an important cause of the current low fertility level in many European countries. On the contrary, in European countries where the decline of marriage has been less pronounced, fertility levels are currently lower than in countries where new living arrangements have become most common.childbearing, Europe, family, fertility

Fisher v. UT Austin - Contextualized Brief

Contextualization of the 2013 Supreme Court case, Fisher v. University of Texas at Austin, in which Abigail Fisher was denied admission. This paper also analyzes past Court cases dealing with affirmative action in the admissions process