61 research outputs found

    Lack of cortico-limbic coupling in bipolar disorder and schizophrenia during emotion regulation

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    Bipolar disorder (BD) and schizophrenia (Sz) share dysfunction in prefrontal inhibitory brain systems, yet exhibit distinct forms of affective disturbance. We aimed to distinguish these disorders on the basis of differential activation in cortico-limbic pathways during voluntary emotion regulation. Patients with DSM-IV diagnosed Sz (12) or BD-I (13) and 15 healthy control (HC) participants performed a well-established emotion regulation task while undergoing functional magnetic resonance imaging. The task required participants to voluntarily upregulate or downregulate their subjective affect while viewing emotionally negative images or maintain their affective response as a comparison condition. In BD, abnormal overactivity (hyperactivation) occurred in the right ventrolateral prefrontal cortex (VLPFC) during up- and downregulation of negative affect, relative to HC. Among Sz, prefrontal hypoactivation of the right VLPFC occurred during downregulation (opposite to BD), whereas upregulation elicited hyperactivity in the right VLPFC similar to BD. Amygdala activity was significantly related to subjective negative affect in HC and BD, but not Sz. Furthermore, amygdala activity was inversely coupled with the activity in the left PFC during downregulation in HC (r=−0.76), while such coupling did not occur in BD or Sz. These preliminary results indicate that differential cortico-limbic activation can distinguish the clinical groups in line with affective disturbance: BD is characterized by ineffective cortical control over limbic regions during emotion regulation, while Sz is characterized by an apparent failure to engage cortical (hypofrontality) and limbic regions during downregulation

    Evolution of active galactic nuclei

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    [Abriged] Supermassive black holes (SMBH) lurk in the nuclei of most massive galaxies, perhaps in all of them. The tight observed scaling relations between SMBH masses and structural properties of their host spheroids likely indicate that the processes fostering the growth of both components are physically linked, despite the many orders of magnitude difference in their physical size. This chapter discusses how we constrain the evolution of SMBH, probed by their actively growing phases, when they shine as active galactic nuclei (AGN) with luminosities often in excess of that of the entire stellar population of their host galaxies. Following loosely the chronological developments of the field, we begin by discussing early evolutionary studies, when AGN represented beacons of light probing the most distant reaches of the universe and were used as tracers of the large scale structure. This early study turned into AGN "Demography", once it was realized that the strong evolution (in luminosity, number density) of the AGN population hindered any attempt to derive cosmological parameters from AGN observations directly. Following a discussion of the state of the art in the study of AGN luminosity functions, we move on to discuss the "modern" view of AGN evolution, one in which a bigger emphasis is given to the physical relationships between the population of growing black holes and their environment. This includes observational and theoretical efforts aimed at constraining and understanding the evolution of scaling relations, as well as the resulting limits on the evolution of the SMBH mass function. Physical models of AGN feedback and the ongoing efforts to isolate them observationally are discussed next. Finally, we touch upon the problem of when and how the first black holes formed and the role of black holes in the high-redshift universe.Comment: 75 pages, 35 figures. Modified version of the chapter accepted to appear in "Planets, Stars and Stellar Systems", vol 6, ed W. Keel (www.springer.com/astronomy/book/978-90-481-8818-5). The number of references is limited upon request of the editors. Original submission to Springer: June 201

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014–2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V

    On the relevance of travel journalism: An introduction

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    Not many people will be instantly familiar with British woman Dale Sheppard-Floyd, but – at least symbolically – she represents a significant milestone in the development of travel and tourism. In fact, the milestone was so significant that the United Nations World Tourism Organization booked Madrid’s venerable Museo del Prado to announce to the world’s media her visit to Spain on 13 December 2012. For Ms Sheppard-Floyd’s arrival for a three-day trip meant that more than one billion times in that year, someone had crossed a border as a tourist. An astounding number, considering that, in 1950, there had been only 25 million tourist arrivals worldwide, and even only two decades previously – in 1990 – the number had been less than half at 435 million arrivals (World Tourism Organization, 2012a, 2012b). While people have traveled for pleasure for millennia (Towner, 1995), tourism really came into its own with the expansion of the middle classes in the 19th and 20th century, and today it is considered the world’s largest business sector, with unprecedented numbers of people venturing outside of their immediate environments to explore the world around them. In 2012, travel and tourism’s total contribution to the world economy amounted to a staggering $6.6 trillion, or 9 per cent of GDP (World Travel & Tourism Council, 2013). More than 260 million jobs were generated by it worldwide, which equates to one in every 11 jobs across the globe. While there were some hiccups during the Global Financial Crisis, growth in 2012 was stronger than in other industries, such as manufacturing, financial services and retail (World Travel & Tourism Council, 2013)..
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