4,509 research outputs found
XZ: Deriving redshifts from X-ray spectra of obscured AGN
Context: Redshifts are fundamental for our understanding of extragalactic
X-ray sources. Ambiguous counterpart associations, expensive optical
spectroscopy and/or multimission multiwavelength coverage to resolve
degeneracies make estimation often difficult in practice.
Aims: We attempt to constrain redshifts of obscured Active Galactic Nuclei
(AGN) using only low-resolution X-ray spectra.
Methods: Our XZ method fits AGN X-ray spectra with a moderately complex
spectral model incorporating a corona, torus obscurer and warm mirror. Using
the Bayesian X-ray Astronomy (BXA) package, we constrain redshift, column
density, photon index and luminosity simultaneously. The redshift information
primarily comes from absorption edges in Compton-thin AGN, and from the Fe
K fluorescent line in heavily obscured AGN. A new generic background
fitting method allows us to extract more information from limited numbers of
source counts.
Results: We derive redshift constraints for 74/321 hard-band detected sources
in the Chandra deep field South. Comparing with spectroscopic redshifts, we
find an outlier fraction of 8%, indicating that our model assumptions are
valid. For three Chandra deep fields, we release our XZ redshift estimates.
Conclusions: The independent XZ estimate is easy to apply and effective for a
large fraction of obscured AGN in todays deep surveys without the need for any
additional data. Comparing to different redshift estimation methods, XZ can
resolve degeneracies in photometric redshifts, help to detect potential
association problems and confirm uncertain single-line spectroscopic redshifts.
With high spectral resolution and large collecting area, this technique will be
highly effective for Athena/WFI observations.Comment: 20 pages, 16 figures in paper, 14 in appendice
Guest Editorial: Navigating the Global Landscape of Scholarly Communication: A Special Issue Exploration
Deprivation of Access to Financial Capital Through Rural Organizations and Its Contribution to Multidimensional Poverty in Nyakagabagaba, South-western Uganda
Financial capital refers to the financial resources that people use to achieve their livelihoods. This article presents an explanation of rural organisations as a strategy for accessing financial capital needed by rural dwellers to improve their livelihood. A study done in Nyakagabaga affirms that rural organisations play an important role in enabling members access financial capital needed to make use of other livelihood assets. Analysis of deprivation in livelihood capital components predicting influence of rural organisations in access to financial capital aids the discussion of income strategy employed upon access to the resource pool. Whereas majority of those deprived in human, physical and natural capital components are more likely to consider rural organisations not influential in access to financial capital needed to meet their livelihood needs, those deprived in social capital are less likely to consider rural organisations not influential in access to financial capital. All in all, it is concluded that rural organisation enhance access to financial capital deprivation of which contributes to multidimensional poverty. Keywords: Financial capital, rural organisations, cooperatives, associations, multidimensional povert
Human Capital Deprivation and Its Contribution to Multidimensional Poverty: Access through Rural Organisations in Nyakagabagaba, South-Western Uganda
This study elaborates how human capital deprivation contributes to the overall multidimensional poverty in Nyakagabagaba and how rural dwellers in the study area belonging to rural organisations (members) access or accumulate human capital desired for their livelihood through the cooperatives and associations they belong to while nonmembers gain access to the needed human capital components through the spillover effects created by rural organisations' function, purposes and services provided. The relationship between perceived rural organisation influence in access to human capital component and the condition (deprived or nondeprived) of human capital components is studied to establish the significance of rural organisations in accessing or accumulating on the components of human capital. Findings show that rural organisations enhance access to human capital, deprivation of which contributes to multidimensional poverty. Keywords:Rural organisations; human capital; multidimensional poverty; livelihoods; cooperatives; association
Region-Referenced Spectral Power Dynamics of EEG Signals: A Hierarchical Modeling Approach
Functional brain imaging through electroencephalography (EEG) relies upon the
analysis and interpretation of high-dimensional, spatially organized time
series. We propose to represent time-localized frequency domain
characterizations of EEG data as region-referenced functional data. This
representation is coupled with a hierarchical modeling approach to multivariate
functional observations. Within this familiar setting, we discuss how several
prior models relate to structural assumptions about multivariate covariance
operators. An overarching modeling framework, based on infinite factorial
decompositions, is finally proposed to balance flexibility and efficiency in
estimation. The motivating application stems from a study of implicit auditory
learning, in which typically developing (TD) children, and children with autism
spectrum disorder (ASD) were exposed to a continuous speech stream. Using the
proposed model, we examine differential band power dynamics as brain function
is interrogated throughout the duration of a computer-controlled experiment.
Our work offers a novel look at previous findings in psychiatry, and provides
further insights into the understanding of ASD. Our approach to inference is
fully Bayesian and implemented in a highly optimized Rcpp package
Repurposing Disused Coal Mines for Geothermal Heat Networks: Towards an Environmental and Social Sustainable Solution
People can identify the likely owner of heartbeats by looking at individuals’ faces
For more than a century it has been proposed that visceral and vasomotor changes inside the body influence and reflect our experience of the world. For instance, cardiac rhythms (heartbeats and consequent heart rate) reflect psychophysiological processes that underlie our cognition and affective experience. Yet, considering that we usually infer what others do and feel through vision, whether people can identify the most likely owner of a given bodily rhythm by looking at someone’s face remains unknown. To address this, we developed a novel two-alternative forced-choice task in which 120 participants watched videos showing two people side by side and visual feedback from one of the individuals’ heartbeats in the centre. Participants’ task was to select the owner of the depicted heartbeats. Across five experiments, one replication, and supplementary analyses, the results show that: i) humans can judge the most likely owner of a given sequence of heartbeats significantly above chance levels, ii) that performance in such a task decreases when the visual properties of the faces are altered (inverted, masked, static), and iii) that the difference between the heart rates of the individuals portrayed in our 2AFC task seems to contribute to participants’ responses. While we did not disambiguate the type of information used by the participants (e.g., knowledge about appearance and health, visual cues from heartbeats), the current work represents the first step to investigate the possible ability to infer or perceive others’ cardiac rhythms. Overall, our novel observations and easily adaptable paradigm may generate hypotheses worth examining in the study of human and social cognition.</p
A male adult skeleton from the Han Dynasty in Shaanxi, China (202 BC–220 AD) with bone changes that possibly represent spinal tuberculosis
Bioarchaeological data for tuberculosis (TB) have been published very sporadically in China or the rest of East Asia. To explore the history of TB in this area, 85 skeletons excavated from the Liuwei Cemetery in Shaanxi, China (202 BC–220 AD) were macroscopically examined to record TB related bone changes. These skeletons represented inhabitants of Maolingyi, an urban area that had a high population density during the Han Dynasty (202 BC–220 CE). Seventeen of the 85 skeletons had spines that were well enough preserved to observe evidence of spinal disease. Among them, a male skeleton aged around 30 years (M34-E) manifested multiple lytic lesions in the eleventh thoracic to second lumbar vertebral bodies (T11 to L2). TB was considered a possible diagnosis for the spinal lesions observed, with differential diagnoses of brucellosis and typhoid. The dense population and overcrowding in urban Maolingyi were considered the potential social risk factors for TB found at this site. The findings of this study contribute to limited knowledge about the history of TB in East Asia and suggest a relationship between population density and the spread of TB in Maolingyi at that time. However, the lack of published bioarchaeological data of TB in East Asia hinders understanding the transmission of TB within Asia and its link to the rest of the world. Further intensive review of archaeological skeletons in Asia is urgently needed
Role of Neuroinflammation in the Neuropsychiatric and Neurological Aspects of COVID-19
International audienc
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