bluuebunny/crossref_metadata_2025_split huggingface dataset:
Commissioning the H i Observing Mode of the Beam Former for the Cryogenically Cooled Focal L-band Array for the GBT (FLAG)
Authors: Pingel N. M. , Pisano D. J. , Ruzindana M. , Burnett M. , Rajwade K. M. , Black R. , Jeffs B. , Warnick K. F. , Lorimer D. R. , Roshi D. Anish , Prestage R. , McLaughlin M. A. , Agarwal D. , Chamberlin T. , Hawkins L. , Jensen L. , Marganian P. , Nelson J. D. , Shillue W. , Smith E. , Simon B. , Tonder V. Van , White S. 
Published: March 2021

Abstract
We present the results of commissioning observations for a new digital beam-forming back end for the Focal plane L-band Array for the Robert C. Byrd Green Bank Telescope (FLAG), a cryogenically cooled Phased Array Feed (PAF) with the lowest measured T
sys/η of any PAF outfitted on a radio telescope to date. We describe the custom software used to apply beam-forming weights to the raw element covariances to create research-quality spectral-line images for the new fine-channel mode, study the stability of the beam weights over time, characterize FLAG’s sensitivity over a frequency range of 150 MHz, and compare the measured noise properties and observed distribution of neutral hydrogen emission from several extragalactic and Galactic sources with data obtained with the current single-pixel L-band receiver. These commissioning runs establish FLAG as the preeminent PAF receiver currently available for spectral-line observations on the world’s major radio telescopes.
Unlocking Starlight Subtraction in Full-data-rate Exoplanet Imaging by Efficiently Updating Karhunen–Loève Eigenimages
Authors: Long Joseph D. , Males Jared R. 
Published: March 2021

Abstract
Starlight subtraction algorithms based on the method of Karhunen–Loève eigenimages have proved invaluable to exoplanet direct imaging. However, they scale poorly in runtime when paired with differential imaging techniques. In such observations, reference frames and frames from which starlight is to be subtracted are drawn from the same set of data, requiring a new subset of references (and eigenimages) for each frame processed to avoid self-subtraction of the signal of interest. The data rates of extreme adaptive optics instruments are such that the only way to make this computationally feasible has been to downsample the data. We develop a technique that updates a precomputed singular value decomposition of the full data set to remove frames (i.e., a “downdate”) without a full recomputation, yielding the modified eigenimages. This not only enables analysis of much larger data volumes in the same amount of time, but also exhibits near-linear scaling in runtime as the number of observations increases. We apply this technique to archival data and investigate its scaling behavior for very large numbers of frames N. The resulting algorithm provides speed improvements of 2.6× (for 200 eigenimages at N = 300) to 140× (at N = 104) with the advantage only increasing as N grows. This algorithm has allowed us to substantially accelerate Karhunen–Loève image projection (KLIP) even for modest N, and will let us quickly explore how KLIP parameters affect exoplanet characterization in large-N data sets.
The Missing Cool Corona in the Flat Magnetic Field around Solar Active Regions
Authors: Singh Talwinder , Sterling Alphonse C. , Moore Ronald L. 
Published: March 2021

Abstract
Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images the full solar disk in several extreme-ultraviolet (EUV) bands that are each sensitive to coronal plasma emissions of one or more specific temperatures. We observe that when isolated active regions (ARs) are on the disk, full-disk images in some of the coronal EUV channels show the outskirts of the AR as a dark moat surrounding the AR. Here we present seven specific examples, selected from time periods when there was only a single AR present on the disk. Visually, we observe the moat to be most prominent in the AIA 171 Å band, which has the most sensitivity to emission from plasma at log10
T = 5.8. By examining the 1D line-of-sight emission measure temperature distribution found from six AIA EUV channels, we find the intensity of the moat to be most depressed over the temperature range log10
T ≈ 5.7–6.2 for most of the cases. We argue that the dark moat exists because the pressure from the strong magnetic field that splays out from the AR presses down on underlying magnetic loops, flattening those loops—along with the lowest of the AR’s own loops over the moat—to a low altitude. Those loops, which would normally emit the bulk of the 171 Å emission, are restricted to heights above the surface that are too low to have 171 Å emitting plasmas sustained in them, according to Antiochos & Noci, while hotter EUV-emitting plasmas are sustained in the overlying higher-altitude long AR-rooted coronal loops. This potentially explains the low-coronal-temperature dark moats surrounding the ARs.
Chandra Probes the X-Ray Variability of M51 ULX-7: Evidence of Propeller Transition and X-Ray Dips on Orbital Periods
Authors: Vasilopoulos Georgios , Koliopanos Filippos , Haberl Frank , Treiber Helena , Brightman Murray , Earnshaw Hannah P. , Gúrpide Andrés 
Published: March 2021

Abstract
We report on the temporal properties of the ultraluminous X-ray (ULX) pulsar M51 ULX-7 inferred from the analysis of the 2018–2020 Swift/X-ray Telescope monitoring data and archival Chandra data obtained over a period of 33 days in 2012. We find an extended low flux state, which might be indicative of propeller transition, lending further support to the interpretation that the neutron star is rotating near equilibrium. Alternatively, this off-state could be related to a variable superorbital period. Moreover, we report the discovery of periodic dips in the X-ray light curve that are associated with the binary orbital period. The presence of the dips implies a configuration where the orbital plane of the binary is closer to an edge-on orientation, and thus demonstrates that favorable geometries are not necessary in order to observe ULX pulsars. These characteristics are similar to those seen in prototypical X-ray pulsars such as Her X-1 and SMC X-1 or other ULX pulsars such as NGC 5907 ULX1.
Correction to the Photometric Colors of the Gaia Data Release 2 with the Stellar Color Regression Method
Authors: Niu Zexi , Yuan Haibo , Liu Jifeng 
Published: March 2021

Abstract
The second Gaia data release (DR2) delivers accurate and homogeneous photometry data of the whole sky of an exquisite quality, reaching down to the unprecedented millimagnitude (mmag) level for the G, G
RP, and G
BP passbands. However, the presence of magnitude-dependent systematic effects at the 10 mmag level limits its power in scientific exploitation. In this work, using about a half million stars in common with the LAMOST DR5, we apply the spectroscopy-based stellar color regression method to calibrate the Gaia G − G
RP and G
BP − G
RP colors. With an unprecedented precision of about 1 mmag, systematic trends with G magnitude are revealed for both colors in great detail, reflecting changes in instrument configurations. Color-dependent trends are found for the G
BP − G
RP color and for stars brighter than G ∼ 11.5 mag. The maximum correction term of the calibration is about 20 mmag in general and varies by a few mmag/mag. A revised color–color diagram of Gaia DR2 is given, and some applications are briefly discussed.
Coronal Wave Trains and Plasma Heating Triggered by Turbulence in the Wake of a CME
Authors: Ye Jing , Cai Qiangwei , Shen Chengcai , Raymond John C. , Mei Zhixing , Li Yan , Lin Jun 
Published: March 2021

Abstract
Magnetohydrodynamic (MHD) turbulence plays an important role for the fast energy release and wave structures related to coronal mass ejections (CMEs). The CME plasma has been observed to be strongly heated during solar eruptions, but the heating mechanism is not understood. In this paper, we focus on the hot, dense region at the bottom of the CME and the generation of coronal wave trains therein using a high-resolution 2.5D MHD simulation. Our results show that the interaction between the tearing current sheet and the turbulence, including the termination shocks (TSs) at the bottom of the CME, can make a significant contribution to heating the CME, and the heating rate in this region is found to be greater than the kinetic energy transfer rate. Also, the turbulence can be somewhat amplified by the TSs. The compression ratio of the TS under the CME can exceed 4 due to thermal conduction, but such a strong TS is hardly detectable in all Solar Dynamics Observatory/Atmospheric Imaging Assembly bands. And turbulence is an indispensable source for the periodic generation of coronal wave trains around the CME.
An assay validation framework to compare and evaluate targeted environmental DNA assays for routine species monitoring
Authors: Thalinger Bettina , Deiner Kristy , Harper Lynsey , Rees Helen , Blackman Rosetta , Sint Daniela , Traugott Michael , Goldberg Caren , Bruce Kat 
Published: March 2021

Environmental DNA (eDNA) analysis utilises trace DNA released by organisms into their environment for species detection and is revolutionising non ‐ invasive species and biodiversity monitoring. However, this technology requires rigorous validation along the whole workflow – from field sampling to statistical analysis – to ensure appropriate and meaningful interpretation of results. Targeted eDNA assays are often validated within a specific system and with particular aims, but without fulfilling predefined criteria. Consequently, their applicability beyond initial development often remains undetermined. Additionally, there tends to be poor understanding of the uncertainties and limitations associated with already published assays and thus potentially inappropriate interpretation of the results they produce. The lack of a “gold standard” limits the incorporation of targeted eDNA assays into species monitoring and policy making by end-users and is therefore key for the future implementation of eDNA-based surveys.
Here, we present a framework (https://edna-validation.com/) and user-friendly criteria for the classification of assays, which is based on previous validation efforts. A 5 ‐ level assay validation scale (“incomplete” to “operational”) was defined by reviewing the current eDNA literature and conducting a meta-analysis on sampling, laboratory practices, detection limits, and detection probabilities. The so far published single species eDNA assays were reviewed for their performance in this new framework and we identified steps within the validation process that often remain untouched. Finally, we provide guidance for end ‐ users as to which criteria are most important for validation and suggest how results obtained from assays at different levels of the validation scale should be interpreted.
Wet grinding of invertebrate bulk samples – a scalable and cost-efficient protocol for metabarcoding and metagenomics
Authors: Buchner Dominik , Haase Peter , Leese Florian 
Published: March 2021

DNA metabarcoding is an efficient tool to characterize invertebrate species composition in environmental samples. Most metabarcoding protocols for invertebrate bulk samples start with sample homogenization, followed by DNA extraction, amplification of a specific marker region and sequencing on a high-throughput sequencer.
Many of the above-mentioned laboratory steps have been verified thoroughly and best practice strategies exist. Giving the amount of research done to validate almost all laboratory steps of metabarcoding workflows it is surprising that there is no clear recommendation for the basis of almost all metabarcoding studies: the homogenization of samples itself.
For homogenization, different devices are used that can be divided into two major categories: bead mills and blenders. While bead-mills accelerate small, hard particles in a closed container or tube to break down specimens into small tissue fragments, blenders work with a rapidly rotating blades that reliably slice specimens as well as other substrate of the sample. Both methods are currently used in metabarcoding studies and have downsides to consider.
Bead-mills rely on single-use plastics and therefore produce a lot of waste and are expensive. In addition to that, processing times can go up to 30 minutes making them unsuitable for large scale studies. Blenders on the other hand offer the opportunity to be cleaned and can handle larger sample volumes in shorter time, with an increased risk of cross-contamination.
We here aimed to develop a fast, robust, cheap and reliable sample homogenization protocol that overcomes the above-mentioned limitations of both methods, i.e. does not produce difficult to discard waste and avoid single-use plastics while reducing overall costs. We tested the performance of the new protocol using six sorted Malaise trap insect samples and six unsorted stream macroinvertebrate kick-net samples. We used 14 technical replicates of each sample and many negative controls per sample (Fig. 1) to quantify impacts of i) insufficient homogenization and ii) possible sources of cross-contamination.
Our results show that homogenization is sufficient after 3 minutes of homogenization. Rinsing the blender with water is sufficient in most cases but leads to low read-numbers in some of the negative controls. These could be further reduced by rinsing the blender with self-made drain-safe sterilization solution based on bleach but far less corrosive than pure bleach. Our results suggest that rinsing 1-2 times for 20 seconds is sufficient to avoid any cross-contamination.
The improvements of the protocol in terms of speed, ease of handling, overall reduction of costs as well as the documented reliability and robustness make it an important candidate for sample homogenization after sampling in particular for large-scale and regulatory metabarcoding biodiversity assessments and monitoring programs.
Getting rid of rain and stars: mitigating inhibition effects in ddPCR assays, the case of the invasive crayfish Pacifastacus leniusculus in the streams of Luxembourg
Authors: Porco David , Hermant Sylvie , Purnomo Chanistya , Horn Mario , Marson Guy , Colling Guy 
Published: March 2021

ddPCR is getting more and more popular in the field of eDNA-based aquatic monitoring. Even if emulsion PCR used in ddPCR confers a partial resistance to inhibition due to the high number of reactions for the same sample (between 10K and 20K), it is not impervious to it. Inhibition impacts the fluorescence amplitude of positive droplets, affecting both their dispersion and their position relatively to the negative droplets cloud. This fluctuation could jeopardize the use of a shared threshold among several samples and thus the objective assignation of the positive droplets.
This is even more critical for low concentration samples such as eDNA samples: the positive droplets are scarce and it is thus crucial to objectively discriminate if they can be counted as positive by establishing an appropriate threshold. Another issue is the artifactual generation of high fluorescence droplets that could be counted as positive with a single threshold solution.
Here we propose a double threshold method to take both high fluorescence droplets and PCR inhibition impact into account allowing for an objective sorting of the positive and negative droplets in ddPCR assays.
Le bébé et les interactions précoces
Authors: Squires Claire 
Published: March 2021

L’observation au cours des thérapies psychanalytiques avec des nourrissons	On ne peut opposer l’observation d’un comportement extérieur à l’exploration d’un matériel inconscient qui s’effectuerait dans le cadre privilégié d’une cure psychanalytique. Au cours des thérapies psychanalytiques avec des nourrissons, le clinicien oscille entre le recueil des interactions manifestes entre la mère et le nourrisson et le dévoilement des fantasmes agis dans leur interrelation. Deux thérapies de nourrissons anorexxiques montrent comment le thérapeute imagine un espace de créativité au travers d’une dynamique relationnelle qui apparaît fondamentale pour le développement.
Les faux-semblants du Front national
Authors: Ivaldi Gilles 
Published: March 2021

Résumé L’analyse empirique des évolutions du programme socio-économique du FN depuis les années 1980 montre que le parti s’est progressivement éloigné de ses préférences néolibérales originelles pour endosser un agenda redistributif, protectionniste et interventionniste, dont le centre de gravité se situe aujourd’hui à gauche de l’axe économique. Cette welfarisation s’est accompagnée d’une saillance croissante des enjeux économiques en 2012, ainsi que d’une diminution significative des ancrages nativistes et social-conservateurs. Le FN conserve toutefois son statut de parti niche centré sur les enjeux culturels, et il ne s’est pas totalement départi de certains de ses marqueurs néolibéraux. La présence d’une forte composante populiste dans son programme témoigne en outre de son adaptation au contexte de crise, mais pose la question de l’existence d’un espace structurel stable pour la nouvelle offre socio-économique frontiste.
Les faux-semblants du Front national
Authors: Crépon Sylvain , Lebourg Nicolas 
Published: March 2021

Résumé Loin des approches souvent péjoratives du militantisme frontiste, il s’agit ici d’aborder les adhérents du FN tant du point de vue sociologique que des convictions qu’ils affichent. À l’heure où le FN de Marine Le Pen s’applique à devenir un « parti comme les autres », qui sont les membres qui le composent ou le rejoignent, quelles sont leurs aspirations et comment trouvent-ils leur place dans l’appareil ?
Le règne des entourages
Authors: Fretel Julien , Meimon Julien 
Published: March 2021

Résumé En dépit de quelques affaires ou mobilisations médiatisées, on connaît mal les assistants parlementaires, personnel pourtant central dans la vie politique et vivier des cabinets ministériels. Leur ancrage dans la Cinquième République est en effet très directement lié à la professionnalisation et à la rationalisation de l’espace politique, chaque parlementaire tendant aujourd’hui à créer sa « petite entreprise politique » en ciblant le recrutement de ses assistants. L’analyse présentée ici, appuyée sur l’étude de leurs tâches quotidiennes et de leurs trajectoires professionnelles et politiques, permet de mettre en lumière ces auxiliaires factotums. Cette forme particulière d’auxiliariat apparaît alors comme une socialisation particulière au jeu politique et comme une formation pratique offrant un capital technique, social et professionnel spécifique, sans pour autant, compte tenu de sa forte précarité et de son institutionnalisation contrariée, être vécue comme un véritable métier.
Le règne des entourages
Authors: Fleischer Julia 
Published: March 2021

Résumé Comparés à la France, au Royaume-Uni ou à la Belgique, les entourages ministériels allemands demeurent bien réduits. Toutefois, ils ont une configuration complexe et dynamique. Ainsi les ministres fédéraux disposent-ils de sources multiples et diversifiées de conseils, qu’ils peuvent manier à leur guise. D’abord, au sommet des ministères, porteurs d’une longue tradition, se trouvent les « fonctionnaires politiques » (politische Beamte), secrétaires d’État administratifs et directeurs généraux qui combinent compétence du bureaucrate et loyauté du collaborateur politisé pour faire l’interface entre chaque ministre et la machine administrative. En outre, dans l’administration centrale des ministères, des directions des affaires générales et de la planification politique, créées dans les années 1970 et dont l’influence a décliné, fournissent encore au ministre une expertise transversale qu’il peut ou non mobiliser en sus de la compétence des directions sectorielles. Enfin, et depuis peu, un ministre allemand dispose de sa propre équipe personnelle (Leitungsstab), peuplée de collaborateurs recrutés le plus souvent parmi les jeunes fonctionnaires pour lesquels ce passage auprès de l’autorité politique est un accélérateur de carrière.
Narration, transmission et traumatisme psychique
Authors: Taïeb Olivier 
Published: March 2021

L’essai Le conteur de Walter Benjamin a été publié en 1936. Benjamin y fait le constat d’une « chute du cours de l’expérience », en particulier après la guerre de 1914-1918, entraînant une crise du récit et une crise de la transmission. La résonance de cet essai avec les écrits psychanalytiques sur le traumatisme psychique est évidente même si Benjamin ne fait pas référence à Freud. Cette relation a été peu soulignée jusqu’à maintenant, à l’exception notable de Janine Altounian. Cet article se propose d’expliciter la part « cachée » de cet essai.
The Unfolded Protein Response Reveals eIF2α Phosphorylation as a Critical Factor for Direct MHC Class I Antigen Presentation
Authors: Nagamine Brandy S , Godil Jamila , Dolan Brian P 
Published: March 2021

Abstract
The ability to modulate direct MHC class I (MHC I) Ag presentation is a desirable goal for the treatment of a variety of conditions, including autoimmune diseases, chronic viral infections, and cancers. It is therefore necessary to understand how changes in the cellular environment alter the cells’ ability to present peptides to T cells. The unfolded protein response (UPR) is a signaling pathway activated by the presence of excess unfolded proteins in the endoplasmic reticulum. Previous studies have indicated that chemical induction of the UPR decreases direct MHC I Ag presentation, but the precise mechanisms are unknown. In this study, we used a variety of small molecule modulators of different UPR signaling pathways to query which UPR signaling pathways can alter Ag presentation in both murine and human cells. When signaling through the PERK pathway, and subsequent eIF2α phosphorylation, was blocked by treatment with GSK2656157, MHC I Ag presentation remain unchanged, whereas treatment with salubrinal, which has the opposite effect of GSK2656157, decreases both Ag presentation and overall cell-surface MHC I levels. Treatment with 4μ8C, an inhibitor of the IRE1α UPR activation pathway that blocks splicing of Xbp1 mRNA, also diminished MHC I Ag presentation. However, 4μ8C treatment unexpectedly led to an increase in eIF2α phosphorylation in addition to blocking IRE1α signaling. Given that salubrinal and 4μ8C lead to eIF2α phosphorylation and similar decreases in Ag presentation, we conclude that UPR signaling through PERK, leading to eIF2α phosphorylation, results in a modest decrease in direct MHC I Ag presentation.
AN ANALYSIS ON THE EFFECTS OF CORONAVIRUS (COVID-19) ON THE FINANCIAL MANAGEMENT OF MULTINATIONAL CORPORATIONS
Authors: Zayed Nurul Mohammad , Islam K. M. Anwarul , Shahi Shahiduzzaman Khan , Rahman Md. Sazidur , Raisa Tahsin Sharmila 
Published: March 2021

This paper develops a sensible framework to get a handle on the spatiotemporal plans of the COVID-19 event, its real nature, and its implications to the Financial Management of MNCs (Multinational Corporations). In the most straightforward structure, the construction of multinational Corporations is included a parent organization that holds all licensed innovation rights, contract makers or undeniable makers which complete the creative work in the nations with low work costs, and the restricted or undeniable wholesalers that sell the completed merchandise in different business sectors and behaviors market explores in their nations of activity. The pandemic effect on financial movement contrasts as far as extent and force. This has delivered unrivaled proportions of shortcomings. This paper tries to diagram the overall elements of worldwide Financial Management of MNCs (Multinational Corporations) with country explicit dangers and primary dangers. Fundamental data is accumulated from different online media, adroit journals, various kinds of examination papers, and other online sources, etc. The globalization of Financial Management of MNCs (Multinational Corporations) is coordinated to the enormous extension of greatness and enhancement of monetary exchanges. At long last, all areas show and portray in detail this subject and give a few suggestions to conquer the present circumstance.
JEL Classification Codes: F36, G32, F23.