scholarly journals The bispectrum and 21-cm foregrounds during the Epoch of Reionization

2020 ◽  
Vol 501 (1) ◽  
pp. 367-382
Author(s):  
Catherine A Watkinson ◽  
Cathryn M Trott ◽  
Ian Hothi
Keyword(s):  
Instrumental Effects ◽  
Future Studies ◽  
Rectangular Window ◽  
Morphological Component Analysis ◽  
Periodic Data ◽  
Morphological Component ◽  
Cross Terms ◽  
Future Data ◽  
The Impact ◽  
Extract Information

ABSTRACT Numerous studies have established the theoretical potential of the 21-cm bispectrum to boost our understanding of the Epoch of Reionization (EoR). We take a first look at the impact of foregrounds (FGs) and instrumental effects on the 21-cm bispectrum and our ability to measure it. Unlike the power spectrum for which (in the absence of instrumental effects) there is a window clear of smooth-spectrum FGs in which it may be detectable, there is no such ‘EoR window’ for the bispectrum. For the triangle configurations and scales we consider, the EoR structures are completely swamped by those of the FGs, and the EoR + FG bispectrum is entirely dominated by that of the FGs. By applying a rectangular window function on the sky combined with a Blackman–Nuttall filter along the frequency axis, we find that spectral, or in our case scale, leakage (caused by FFTing non-periodic data) suppresses the FG contribution so that cross-terms of the EoR and FGs dominate. While difficult to interpret, these findings motivate future studies to investigate whether filtering can be used to extract information about the EoR from the 21-cm bispectrum. We also find that there is potential for instrumental effects to seriously corrupt the bispectrum. FG removal using GMCA (generalized morphological component analysis) is found to recover the EoR bispectrum to a reasonable level of accuracy for many configurations. Further studies are necessary to understand the error and/or bias associated with FG removal before the 21-cm bispectrum can be practically applied in analysis of future data.

scholarly journals Imaging with Coherent X-rays: From the Early Synchrotron Tests to SYNAPSE

2021 ◽  
Vol 7 (8) ◽  
pp. 132
Author(s):  
Giorgio Margaritondo ◽  
Yeukuang Hwu
Keyword(s):  
Human Brain ◽  
International Collaboration ◽  
Phase Contrast ◽  
Asia Pacific ◽  
X Rays ◽  
New Techniques ◽  
Simple Description ◽  
Contrast Radiography ◽  
The Impact ◽  
Extract Information

The high longitudinal and lateral coherence of synchrotron X-rays sources radically transformed radiography. Before them, the image contrast was almost only based on absorption. Coherent synchrotron sources transformed radiography into a multi-faceted tool that can extract information also from “phase” effects. Here, we report a very simple description of the new techniques, presenting them to potential new users without requiring a sophisticated background in advanced physics. We then illustrate the impact of such techniques with a number of examples. Finally, we present the international collaboration SYNAPSE (Synchrotrons for Neuroscience—an Asia-Pacific Strategic Enterprise), which targets the use of phase-contrast radiography to map one full human brain in a few years.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals Delineating the Polarized and Unpolarized Parton Structure of the Nucleon

2015 ◽  
Vol 37 ◽  
pp. 1560053
Author(s):  
Pedro Jimenez-Delgado
Keyword(s):  
Parton Distribution ◽  
Distribution Functions ◽  
Distribution Analysis ◽  
Coupling Constant ◽  
Parton Distribution Functions ◽  
Careful Treatment ◽  
Future Data ◽  
The Impact

Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a discussion of the role of the input scale in parton distribution analysis. In the second part of the talk recent results on the determination of spin-dependent PDFs from the JAM collaboration are reported, including a careful treatment of hadronic and nuclear corrections, as well as reports on the impact of present and future data in our understanding of the spin of the nucleon.

Reflections on the biochemistry ofEchinococcus: past, present and future

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1643-1652 ◽  
Author(s):  
D. P. McMANUS
Keyword(s):  
Hydatid Disease ◽  
Biochemical Analysis ◽  
Species Variation ◽  
Research Directions ◽  
Future Studies ◽  
Tegumental Surface ◽  
Research Areas ◽  
General Metabolism ◽  
New Research ◽  
The Impact

SUMMARYThis review discusses 5 of my earliest papers on the biochemistry of larvalEchinococcuspublished inParasitologyin the 1970s and 1980s. Two of the publications consider aspects of the basic biochemistry, intermediary metabolism and the regulation of respiratory pathways inE. granulosusandE. multilocularis, and emphasize the existence of inter- and intra-species variation in their general metabolism. The third reports on the detailed biochemical analysis of the tegumental surface of the protoscolex ofE. granulosus, and the final 2 papers describe the genomic cloning ofEchinococcusDNA fragments and their use, along with other DNA markers, in molecular identification ofE. granulosusisolates collected worldwide from areas endemic for hydatid disease. A number of years have elapsed since these publications inParasitologyand, in this Centenary Issue article, I reflect briefly on some of the subsequent studies undertaken in these research areas that have advanced the field. As well, I provide brief insight on new research directions, emphasizing the impact of molecular biology and associated techniques on future studies ofEchinococcusand hydatid disease.

scholarly journals SZ and CMB reconstruction using generalized morphological component analysis

2008 ◽  
Vol 5 (4) ◽  
pp. 307-317 ◽  
Author(s):  
J. Bobin ◽  
Y. Moudden ◽  
J.-L. Starck ◽  
J. Fadili ◽  
N. Aghanim
Keyword(s):  
Component Analysis ◽  
Morphological Component Analysis ◽  
Morphological Component

scholarly journals #GERIATRICS: AN ANALYSIS OF THE IMPACT OF THE GERIATRICS TWITTER NETWORK

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S337-S337
Author(s):  
Varun Ayyaswami ◽  
Arpan Prabhu ◽  
Steven Gambert
Keyword(s):  
Network Analysis ◽  
Geriatric Medicine ◽  
The United States ◽  
Annual Growth ◽  
Social Media Analytics ◽  
User Characteristics ◽  
Future Studies ◽  
Digital Community ◽  
Support Organizations ◽  
The Impact

Abstract Twitter connects an international community of healthcare stakeholders, potentially augmenting access to information related to geriatric medicine. The purpose of this study is to analyze the geriatric medicine Twitter network, and we hypothesize this community has substantially grown in the last six years. We analyzed all publicly available tweets including the hashtag #geriatrics from January 1, 2013-January 1, 2019 using Symplur Signals, a health care social media analytics platform. We evaluated #geriatrics metrics over time related to activity, content analysis, user characteristics, engagement, and network analysis. A total of 159,008 tweets (containing 42.8% re-tweets) with the hashtag #geriatrics were written by 29,443 users, resulting in 393.6 million impressions. The number of tweets increased from 9,705 in 2013 to 39,151 in 2018 (32.2% compound annual growth); users increased from 3,366 in 2013 to 29,443 in 2018 (55.3% compound annual growth). Users were primarily found in the United States, United Kingdom, and Canada. The most commonly trending topic from 2013-2015 and from 2016-2018 was ‘older adults’. The top hashtags included in tweets with #geriatrics were #job, #aging, and #hpm (hospice and palliative medicine). Network analysis showed central hubs to be medical journals, provider organizations, individual physicians, and individual advocates. The top 150 influencers consisted primarily of physicians (49.1%), advocate/support organizations (13.8%), and media organizations (6.3%). The use of Twitter to promote geriatric medicine using #geriatrics has matured into an international digital community of interest. Future studies should examine hashtags related to age prevalent illnesses and hashtags likely to be used by patients.

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