bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifunctional Liposomes Modulate Purinergic Receptor-Induced Calcium Wave in Cerebral Microvascular Endothelial Cells and Astrocytes: New Insights for Alzheimer’s disease
Authors: Forcaia Greta , Formicola Beatrice , Terribile Giulia , Negri Sharon , Lim Dmitry , Biella Gerardo , Re Francesca , Moccia Francesco , Sancini Giulio
Published: January 2021

In light of previous results, we assessed whether liposomes functionalized with ApoE-derived peptide (mApoE) and phosphatidic acid (PA) (mApoE-PA-LIP) impacted on intracellular calcium (Ca2+) dynamics in cultured human cerebral microvascular endothelial cells (hCMEC/D3), as an in vitro human blood-brain barrier (BBB) model, and in cultured astrocytes. mApoE-PA-LIP pre-treatment actively increased both the duration and the area under the curve (A.U.C) of the ATP-evoked Ca2+ waves in cultured hCMEC/D3 cells as well as in cultured astrocytes. mApoE-PA-LIP increased the ATP-evoked intracellular Ca2+ waves even under 0 [Ca2+]e conditions, thus indicating that the increased intracellular Ca2+ response to ATP is mainly due to endogenous Ca2+ release. Indeed, when Sarco-Endoplasmic Reticulum Calcium ATPase (SERCA) activity was blocked by cyclopiazonic acid (CPA), the extracellular application of ATP failed to trigger any intracellular Ca2+ waves, indicating that metabotropic purinergic receptors (P2Y) are mainly involved in the mApoE-PA-LIP-induced increase of the Ca2+ wave triggered by ATP. In conclusion, mApoE-PA-LIP modulate intracellular Ca2+ dynamics evoked by ATP when SERCA is active through inositol-1,4,5-trisphosphate-dependent (InsP3) endoplasmic reticulum Ca2+ release. Considering that P2Y receptors represent important pharmacological targets to treat cognitive dysfunctions, and that P2Y receptors have neuroprotective effects in neuroinflammatory processes, the enhancement of purinergic signaling provided by mApoE-PA-LIP could counteract Aβ-induced vasoconstriction and reduction in cerebral blood flow (CBF). Our obtained results could give an additional support to promote mApoE-PA-LIP as effective therapeutic tool for Alzheimer’s disease (AD).
On the explicit representation of the trace space $$H^{\frac{3}{2}}$$ and of the solutions to biharmonic Dirichlet problems on Lipschitz domains via multi-parameter Steklov problems
Authors: Lamberti Pier Domenico , Provenzano Luigi
Published: January 2021

We consider the problem of describing the traces of functions in $$H^2(\Omega )$$

H
2

(
Ω
)

on the boundary of a Lipschitz domain $$\Omega $$
Ω
of $$\mathbb R^N$$

R
N

, $$N\ge 2$$

N
≥
2

. We provide a definition of those spaces, in particular of $$H^{\frac{3}{2}}(\partial \Omega )$$

H

3
2

(
∂
Ω
)

, by means of Fourier series associated with the eigenfunctions of new multi-parameter biharmonic Steklov problems which we introduce with this specific purpose. These definitions coincide with the classical ones when the domain is smooth. Our spaces allow to represent in series the solutions to the biharmonic Dirichlet problem. Moreover, a few spectral properties of the multi-parameter biharmonic Steklov problems are considered, as well as explicit examples. Our approach is similar to that developed by G. Auchmuty for the space $$H^1(\Omega )$$

H
1

(
Ω
)

, based on the classical second order Steklov problem.
Bonus Systems as Tools for ‘Managing’ Managers – the Behavioural Effects of Performance-Based Financial Rewards
Authors: Keßels Isabelle
Published: January 2021

In traditional reward systems, managers’ key performance indicators must surpass an agreed target in order to achieve a financial bonus. This system is designed to motivate high performance; yet adverse behavioural effects are often observed. These include middle managers becoming incentivised to game the reward system and target negotiation process they are subject to. This paper discusses three approaches to preventing such undesirable behavioural effects: Firstly, a linear pay-for-performance system without a target floor for receiving a performance bonus. Secondly, a bonus banking system where managers participate at the company’s losses as well as its gains. Thirdly, a proposal that uses the Beyond Budgeting approach which radically negates the core premises of the traditional reward system and replaces rewards for individual manager performance with those for wider team performance. These three approaches are compared and evaluated with respect to their potential to prevent unwanted manager behaviour, and on consideration of how effectively they may be operationalised.
Projected Changes in Temperature and Precipitation Over the United States, Central America, and the Caribbean in CMIP6 GCMs
Authors: Almazroui Mansour , Islam M. Nazrul , Saeed Fahad , Saeed Sajjad , Ismail Muhammad , Ehsan Muhammad Azhar , Diallo Ismaila , O’Brien Enda , Ashfaq Moetasim , Martínez-Castro Daniel , Cavazos Tereza , Cerezo-Mota Ruth , Tippett Michael K. , Gutowski William J. , Alfaro Eric J. , Hidalgo Hugo G. , Vichot-Llano Alejandro , Campbell Jayaka D. , Kamil Shahzad , Rashid Irfan Ur , Sylla Mouhamadou Bamba , Stephenson Tannecia , Taylor Michael , Barlow Mathew
Published: January 2021

The Coupled Model Intercomparison Project Phase 6 (CMIP6) dataset is used to examine projected changes in temperature and precipitation over the United States (U.S.), Central America and the Caribbean. The changes are computed using an ensemble of 31 models for three future time slices (2021–2040, 2041–2060, and 2080–2099) relative to the reference period (1995–2014) under three Shared Socioeconomic Pathways (SSPs; SSP1-2.6, SSP2-4.5, and SSP5-8.5). The CMIP6 ensemble reproduces the observed annual cycle and distribution of mean annual temperature and precipitation with biases between − 0.93 and 1.27 °C and − 37.90 to 58.45%, respectively, for most of the region. However, modeled precipitation is too large over the western and Midwestern U.S. during winter and spring and over the North American monsoon region in summer, while too small over southern Central America. Temperature is projected to increase over the entire domain under all three SSPs, by as much as 6 °C under SSP5-8.5, and with more pronounced increases in the northern latitudes over the regions that receive snow in the present climate. Annual precipitation projections for the end of the twenty-first century have more uncertainty, as expected, and exhibit a meridional dipole-like pattern, with precipitation increasing by 10–30% over much of the U.S. and decreasing by 10–40% over Central America and the Caribbean, especially over the monsoon region. Seasonally, precipitation over the eastern and central subregions is projected to increase during winter and spring and decrease during summer and autumn. Over the monsoon region and Central America, precipitation is projected to decrease in all seasons except autumn. The analysis was repeated on a subset of 9 models with the best performance in the reference period; however, no significant difference was found, suggesting that model bias is not strongly influencing the projections.
The Climatic Analysis of Summer Monsoon Extreme Precipitation Events over West Africa in CMIP6 Simulations
Authors: Klutse Nana Ama Browne , Quagraine Kwesi Akumenyi , Nkrumah Francis , Quagraine Kwesi Twentwewa , Berkoh-Oforiwaa Rebecca , Dzrobi Joshua Fafanyo , Sylla Mouhamadou Bamba
Published: January 2021

We evaluate the capability of 21 models from the new state-of-the-art Coupled Model Intercomparison Project, Phase 6 (CMIP6) in the representation of present-day precipitation characteristics and extremes along with their statistics in simulating daily precipitation during the West African Monsoon (WAM) period (June–September). The study uses a set of standard extreme precipitation indices as defined by the Expert Team on Climate Change Detection and Indices constructed using CMIP6 models and observational datasets for comparison. Three observations; Global Precipitation Climatology Project (GPCP), Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), and Tropical Applications of Meteorology using SATellite and ground-based observation (TAMSAT) datasets are used for the validation of the model simulations. The results show that observed datasets present nearly the same spatial pattern but discrepancies in the magnitude of rainfall characteristics. The models show substantial discrepancies in comparison with the observations and among themselves. A number of the models depict the pattern of rainfall intensity as observed but some models overestimate the pattern over the coastal parts (FGOALS-f3-L and GFDL-ESM4) and western part (FGOALS-f3-L) of West Africa. All model simulations explicitly show the pattern of wet days but with large discrepancies in their frequencies. On extreme rainfall, half of the models express more intense extremes in the 95th percentiles while the other half simulate less intense extremes. All the models overestimate the mean maximum wet spell length except FGOALS-f3-L. The spatial patterns of the mean maximum dry spell length show a good general agreement across the different models, and the observations except for four models that show an overestimation in the Sahara subregion. INM-CM4-8 and INM-CM5-0 display smaller discrepancies from their long-term average rainfall characteristics, in terms of extreme rainfall estimates than the other CMIP6 datasets. For the frequency of heavy rainfall, TaiESM1 and IPSL-CMGA-LR perform better when compared with observational datasets. MIROC6 and GFDL-ESM4 displayed the largest error in representing the frequency of heavy rainfall and 95th percentile extremes, and therefore, cannot be reliable. The study has assessed how rainfall extremes are captured in both observation and the models. Though there are some discrepancies, it gives room for improvement of the models in the next version of CMIP.
Diagnostic Methods for Vaginal Stenosis and Compliance to Vaginal Dilator Use: A Systematic Review
Authors: Haddad Natalia Carion , Soares Brollo Leila Cristina , Pinho Oliveira Marco Aurelio , Bernardo-Filho Mario
Published: January 2021

Background

Vaginal stenosis (VS) is a common side effect of pelvic radiotherapy for gynecological cancer in women. It has a high incidence variability, likely due to unstandardized and subjective assessment methods. Furthermore, even though the worldwide standard treatment for VS is vaginal dilation, low compliance rates have been noted.

Aim

To evaluate the parameters used to diagnose VS and to assess whether the lack of an objective measure of VS hampers vaginal dilator use.

Methods

A systematic review in accordance with the PRISMA reporting guidelines was conducted. PubMed, EMBASE, and Web of Science databases were searched. Randomized trials and prospective, retrospective, and cross-sectional studies published from January 2011 to February 2020 were included.

Outcomes

The main outcome of this study was a review of the published literature on assessment methods for VS and compliance to vaginal dilator use.

RESULTS

Of the 28 articles obtained, only 7 used objective methods to measure the vaginal volume. 3 studies have demonstrated patient’s concern with VS development and showed a high compliance to dilator use, whereas others reported several barriers to dilator use.

Clinical Implications

Lack of an objective assessment method can be a predisposing factor for uncertain VS incidence rates and impair compliance to vaginal dilator therapy, leading to long-term VS and sexual dysfunction.

Strengths & Limitations

This is the first systematic review on the heterogeneity of VS evaluation methods and compliance to vaginal dilator use. All studies were comprehensively evaluated by 2 reviewers. The limitations included the heterogeneity of the study designs and the unstandardized criteria used to classify stenosis or to evaluate compliance to dilator use. Although 3 well-known databases were used, the inclusion of more data sources could have increased the number of publications included in this review.

CONCLUSION

VS is frequently diagnosed using subjective parameters. Few unstandardized objective methods are used to evaluate this condition. Regarding compliance to vaginal dilator use, there was a high dropout rate during follow-up and no consensus on starting time or ideal usage.
From satisficing to artificing: The evolution of administrative decision-making in the age of the algorithm
Authors: Snow Thea
Published: January 2021

Algorithmic decision tools (ADTs) are being introduced into public sector organizations to support more accurate and consistent decision-making. Whether they succeed turns, in large part, on how administrators use these tools. This is one of the first empirical studies to explore how ADTs are being used by Street Level Bureaucrats (SLBs). The author develops an original conceptual framework and uses in-depth interviews to explore whether SLBs are ignoring ADTs (algorithm aversion); deferring to ADTs (automation bias); or using ADTs together with their own judgment (an approach the author calls “artificing”). Interviews reveal that artificing is the most common use-type, followed by aversion, while deference is rare. Five conditions appear to influence how practitioners use ADTs: (a) understanding of the tool (b) perception of human judgment (c) seeing value in the tool (d) being offered opportunities to modify the tool (e) alignment of tool with expectations.
Eroding sexism: A Yogācāra dialectics of gender
Authors: Li Jingjing
Published: January 2021

In this article, I explore how we can expand the project of Buddhist feminism by drawing on Chinese Yogācāra philosophy. With a focus on the writings of Xuanzang (c. 602–664) and his disciple Kuiji (632–682), I investigate how the Yogācāra theory of consciousness can be read as a gendered account of non-duality. The term ‘Yogācāra dialectics’ is thus coined to describe this theory of non-duality that highlights fluidity and transformability. As I will argue, Chinese Yogācārins developed the dialectics of gender by means of which they were able to subtly erode sexism in premodern times.
Unseating “State” and “Archive”: Mobility and Manipulation in Past Environments and Present Praxis
Authors: Ferguson Heather
Published: January 2021

These concluding reflections assess how the contributors to this special issue intervene in key assumptions that shape the current field of archival studies. As the “archival turn” gains ground, forms of Euro- and state-centrism reappear in scholarship otherwise innovative in its attention to the textual remnants of the past. Here, instead, we explore the methodological stakes involved in defining both the “archive” and the historical power brokers who created and preserved a documentary record in pursuit of their varied social, cultural, economic, and political projects. The essay points to the resurgence of culturalist and civilisational indices for comparative archivistics, and follows the arguments collected in this issue to assert by contrast the often uneven and uneasy regional, administrative, and procedural definitions at work within preserved records. Identifying “mobility” as both a methodological tactic and a historical process, this conclusion presents a fluid rather than fixed textual landscape and presents an alternative frame for investigating preservationist practices.
From Kruskal’s theorem to Friedman’s gap condition
Authors: Freund Anton
Published: January 2021

Harvey Friedman’s gap condition on embeddings of finite labelled trees plays an important role in combinatorics (proof of the graph minor theorem) and mathematical logic (strong independence results). In the present paper we show that the gap condition can be reconstructed from a small number of well-motivated building blocks: It arises via iterated applications of a uniform Kruskal theorem.
Personality Characteristics and Acute Symptom Response Predict Chronic Symptoms After Mild Traumatic Brain Injury
Authors: Parker Hillary A. , Ranson Jana , McCrea Michael A. , Hoelzle James , deRoon-Cassini Terri , Nelson Lindsay D.
Published: January 2021

Objective:

Despite consensus that personality influences mild traumatic brain injury (mTBI) recovery, it has been underexamined. We evaluated the extent to which diverse personality and psychiatric symptom dimensions predict mTBI recovery.

Methods:

This prospective cohort study involved psychological assessments of hospital patients with mTBI (n = 75; median = 2 days post-injury, range = 0–12 days) and orthopedic trauma controls (OTC; n = 79) who were used for comparison in mediation modeling. Chronic symptoms were evaluated at 3 months after mTBI (n = 50) using the Sport Concussion Assessment Tool (SCAT) symptom checklist. Linear regression analyses were used to identify the predominant predictors of chronic symptoms in mTBI. Modern mediation analyses tested the hypothesis that personality traits predict chronic symptoms through acute psychological response to injury.

Results:

In mTBI, trait psychoticism directly predicted chronic mTBI symptoms and was the strongest personality predictor overall. Furthermore, an internalizing personality dimension emphasizing negative affect/emotionality and detachment predicted chronic mTBI symptoms indirectly through enhancement of acute somatic complaints. In OTC, internalizing personality acted through the same mediator as in mTBI, whereas the effect of psychoticism was also mediated through acute somatic complaints. There was varying support for a moderated direct effect of personality traits at low levels of positive emotionality across models.

Conclusion:

These causal models provide novel insights about the role of personality in mTBI symptom recovery, highlighting the complexity of how psychological processes may interact to affect recovery and revealing that some of these processes may be non-specific to brain injury.
Young learners’ L2 English after the onset of instruction: longitudinal development of L2 proficiency and the role of individual differences
Authors: De Wilde Vanessa , Brysbaert Marc , Eyckmans June
Published: January 2021

In this study we investigated 107 young learners’ L2 English receptive vocabulary knowledge and speaking skills at two points in time, before and after the onset of instruction. We also investigated the role of several individual difference variables: out-of-school exposure to English, length of instruction, analytic reasoning ability, working memory, L1 vocabulary knowledge and prior L2 knowledge. Results show that L2 English proficiency in receptive vocabulary knowledge and speaking skills greatly improved over time and that the effects of schooling and contextual learning are largely additive. The main predictor of the children's proficiency at time 2 was their L2 prior knowledge, which they had acquired through contextual language learning before getting formal education. When considering the other variables that predicted L2 proficiency, the contribution of internal variables (L1 vocabulary size and working memory) was considerably smaller than that of external variables (out-of-school exposure and length of instruction).
Optical spectroscopy of nearby type1-LINERs
Authors: Cazzoli Sara , Márquez Isabel , Masegosa Josefa , del Olmo Ascensión , Pović Mirjana , González-Martín Omaira , Balmaverde Barbara , Hernández-García Lorena , García-Burillo Santiago
Published: January 2021

We present the highlights from our recent study of 22 local (z < 0.025) type-1 LINERs from the Palomar Survey, on the basis of optical long-slit spectroscopic observations taken with TWIN/CAHA, ALFOSC/NOT and HST/STIS. Our goals were threefold: (a) explore the AGN-nature of these LINERs by studying the broad (BLR-originated) Hαλ 6563 component; (b) derive a reliable interpretation for the multiple narrow components of emission lines by studying their kinematics and ionisation mechanism (via standard BPTs); (c) probe the neutral gas in the nuclei of these LINERs for the first time. Hence, kinematics and fluxes of a set of emission lines, from Hβ λ4861 to [SII]λλ 716,6731, and the NaDλλ5890,5896 doublet in absorption have been modelled and measured, after the subtraction of the underlying light from the stellar component.
Recent results of measuring black hole masses via reverberation mapping
Authors: Kaspi Shai
Published: January 2021

Over the past three decades more than 100 Active Galactic Nuclei (AGNs) were measured using the reverberation mapping technique. This technique uses the response of the line emission in the Broad Line Region (BLR) to continuum emission variation and yields a measure for the distance of the BLR from the central Black Hole (BH). This in turn is used to measure the BH’s mass. Almost all of these measurements are of low-luminosity AGNs while for quasars with luminosities higher than 1046 rg s−1 there are hardly any attempts of reverberation mapping. This contribution reports on recent results from a two-decades campaigns to measure the BH mass in high-luminosity quasars using the reverberation mapping technique. BLR distance from the BH, BH mass, and AGN UV luminosity relations over eight orders of magnitude in luminosity are presented, pushing the luminosity limit to the highest point so far.
Revisiting old (AGN) friends - what’s changed in their spectral looks
Authors: Winkler Hartmut
Published: January 2021

Active Galactic Nuclei (AGN) have long been known to be variable, but the amplitude, timescale and nature of these changes can often differ dramatically from object to object. The richest source of information about the properties of AGN and the physical processes driving these remains the optical spectrum. While this spectrum has remained remarkably steady over decades for some AGN, other objects, referred to as Changing Look AGN, have experienced a comprehensive spectral transformation. Developments in the detection technology have enabled detailed probing in other wavebands, highlighting for example often quite different variability patterns for high energy emission. This paper explores the current characteristics of some long-known (and almost forgotten) Seyfert galaxies. It compares their present optical spectral properties, determined from recent observations at the South African Astronomical Observatory, with those from much earlier epochs. It furthermore considers the implication of the changes that have taken place, alternatively the endurance of specific spectral features, on our understanding of the mechanisms of the observed targets in particular, and on AGN models in general.
Role of active galactic nuclei and flow of relativistic jets
Authors: Tassama Abdissa , Biressa Tolu
Published: January 2021

The astrophysics of Active Galactic Nuclei (AGN) is one of the long outstanding issues in searches among the scientific communities raised with diverse perspectives like nebula, quasars, etc some decades ago. Currently, this exotic system is at least understood as the center of an active galaxy. Thus, the consensus of this recent theory has opened up a number of research issues for the progress of astrophysical science including how the hosting galaxy evolves with the AGN, how matter and energy flow towards and outwards, etc. Moreover, most of the AGNs possess Supermassive Black Holes (SMBHs) and accrete matter at a very high rate as current observations report. Consequently, both observations of electromagnetic (EM) spectrum and Gravity Waves (GWs) will considered to provide complementary information about the AGNs and the roles in their environments including black holes in their centers, outflow and inflow of matter-energy. Interested with this background rationale, we study the mechanisms of AGN interaction with its environment and flow of relativistic jets where General Relativistic (GR) Magneto-Hydrodynamic (MHD) equations are being considered. The solutions of the field equations are treated with a metric that involves charged systems for the possible relativistic jets including accretions. Then, numerical data is being generated using the latest version Mathematic software. Finally, the theoretical data is being compared with that of observation for validation of the model.
The role of active galactic nuclei in galaxy evolution in terms of radial pressure
Authors: Tolu Biressa , Feyissa Abate
Published: January 2021

Irrespective of whether Active Galactic Nuclei (AGN) is cored with Supermassive Black Holes (SMBH) or not, there is a general consensus that observations indicate that the AGN plays fundamental role in galaxy evolution. The accretion disc powered fueling of the AGN and counter-feedback on its environment in the form of stress-energy-momentum along the radial component and an associated polodial jets seems viable model. On the theoretical ground there is no unified theory that compromise the observations. But there are pull of such diverse physics simulated to describe the observational works. So, there is unsettled theoretical framework how the activity of the AGN plays role in the evolution of host galaxy. Motivated by this we studied the role of AGN on its host galaxy evolution where General relativistic (GR) Magnetohydrodynamics (MHD) equation is considered to derive radial pressure that invokes star forming cold gases. Methodologically the central engine of the AGN is considered with SMBH/pseudo-SMBH. Locally, around the AGN, Reissner-Nordstrom-de Sitter metric is considered that reduces to the Schwarzschoild-de Sitter (SdS) background. Geometrically, a simple spherical geometry is superimposed with central disc structure assumed by cored void mass ablating model. The results of the work indicates that the AGN plays role in galaxy evolution, especially in the nearby environment. Also we report that the adjacent envelope to the AGN seems quiet with no activity in formation.
Detailed characterisation of LINERs and retired galaxies in the local universe
Authors: Mazengo Daudi T. , Pović Mirjana , Jiwaji Noorali T. , Sunzu Jefta M.
Published: January 2021

We present a detailed characterisation of physical properties of low-ionization nuclear emission-line regions (LINERs) and retired galaxies (RGs) in the local universe for redshift range 0 <z< 0.4 and two subrangesz< 0.4 and 0.1 <z< 0.4. Furthermore, we test the effectiveness of WHAN diagnostic diagram in separating the two populations. We used photometric data, public spectroscopic data and morphological classification from SDSS-DR8, MPA-JHU SDSS-DR8 catalogue and Galaxy Zoo survey, respectively. We studied the distribution of LINERs, RGs and AGN-LINERs in relation to luminosity, stellar mass, star formation rate (SFR), colour, and their location on the SFR-stellar mass and colour-stellar mass diagrams. We then studied the morphologies of both populations. Results have shown that for higher redshift range, AGN-LINERs have higher apparentgmagnitude, SFRs and dominate on/above the main sequence (MS) of star formation compared to RGs. However, both populations have similar stellar mass and luminosity distributions at all redshift ranges hence suggesting a significant difference in terms of star formation of RGs and AGN-LINERs with redshift. However, larger and more complete samples of LINERs are needed from the future surveys (e.g., LSST) and missions (e.g., JWST) to study in more details the properties of RGs and AGN-LINERs and find alternative methods of separating the two populations, since using simply WHAN diagram from our study we do not find it to be effective for separating the two populations.
Exploring the X-ray universe via timing: mass of the active galactic nucleus black hole XMMUJ134736.6+173403
Authors: Šrámková Eva , Goluchová K. , Török G. , Abramowicz Marek A. , Stuchlík Z. , Horák Jiří
Published: January 2021

A strong quasi-periodic modulation has recently been revealed in the X-ray flux of the X-ray source XMMUJ134736.6+173403. The two observed twin-peak quasiperiodic oscillations (QPOs) exhibit a 3:1 frequency ratio and strongly support the evidence for the presence of an active galactic nucleus black hole (AGN BH). It has been suggested that detections of twin-peak QPOs with commensurable frequency ratios and scaling of their periods with BH mass could provide the basis for a method intended to determine the mass of BH sources, such as AGNs. Assuming the orbital origin of QPOs, we calculate the upper and lower limit on the AGN BH mass M, reaching M ≍ 107–109M⊙. Compared to mass estimates of other sources, XMMUJ134736.6+173403 appears to be the most massive source with commensurable QPO frequencies, and its mass represents the current observational upper limit on the AGN BH mass obtained from the QPO observations.
Probing black hole - host galaxy scaling relations with obscured type II AGN
Authors: Baron Dalya
Published: January 2021

The scaling relations between supermassive black holes and their host galaxy properties are of fundamental importance in the context black hole-host galaxy co-evolution throughout cosmic time. Beyond the local universe, such relations are based on black hole mass estimates in type I AGN. Unfortunately, for this type of objects the host galaxy properties are more difficult to obtain since the AGN dominates the observed flux in most wavelength ranges. In this poster I will present a new correlation we discovered between the narrow L([OIII])/L(Hβ) line ratio and the FWHM(broad Hα). This scaling relation ties the kinematics of the gas clouds in the broad line region to the ionization state of gas in the narrow line region, connecting the properties of gas clouds kiloparsecs away from the black hole to material gravitationally bound to it on sub-parsec scales. This relation can be used to estimate black hole masses from narrow emission lines only, and thus brings the missing piece required to estimate black hole masses in obscured type II AGN. Using this technique, we estimate the black hole mass of about 10,000 type II AGN, and present, for the first time, M(BH)-sigma and M(BH)-M(stars) scaling relations for this population. These relations are remarkably consistent with those observed for type I AGN, suggesting that this new method may perform as reliably as the classical estimate used in non-obscured type I AGN. These findings open a new window for studies of black hole-host galaxy co-evolution throughout cosmic time.
Optical variability of faint quasars
Authors: Ewnu Kassa Endalamaw
Published: January 2021

The variability properties of a quasar sample, spectroscopically complete to magnitude J = 22.0, are investigated on a time baseline of 2 yr, using three different photometric bands (U, J and F). The original sample was obtained using a combination of different selection criteria: colours, slitless spectroscopy and variability, based on a time baseline of 1 yr. The main goals of this work are two-fold: first, to derive the percentage of variable quasars on a relatively short time baseline; secondly, to search for new quasar candidates, missed by the other selection criteria, and thus to estimate the completeness of the spectroscopic sample. In order to achieve these goals, we have extracted all the candidate variable objects from a sample of about 1800 stellar or quasi-stellar objects with limiting magnitude J = 22.50 over an area of about 0.50 deg2. We find that > 65% of all the objects selected as possibly variable are either confirmed quasars or quasar candidates, on the basis of their colours. This percentage increases even further if we exclude from our lists of variable candidates a number of objects equal to that expected on the basis of ‘contamination’ induced by our photometric errors. The percentage of variable quasars in the spectroscopic sample is also high, reaching about 50%. On the basis of these results, we can estimate that the incompleteness of the original spectroscopic sample is < 12%. We conclude that variability analysis of data with small photometric errors can be successfully used as an efficient and independent (or at least auxiliary) selection method in quasar surveys, even when the time baseline is relatively short. Finally, when corrected for the different intrinsic time lags corresponding to a fixed observed time baseline, our data do not show a statistically significant correlation between variability and either absolute luminosity or redshift.
Measuring therapist cognitions contributing to therapist drift: a qualitative study
Authors: Rameswari Tiffany , Hayes Brett , Perera-Delcourt Ramesh
Published: January 2021

Therapist beliefs have been identified as a contributing factor to ‘therapist drift’ in cognitive behavioural therapy (CBT). Scales have been developed to measure therapist beliefs, but none explicitly measure ‘therapy-interfering cognitions’, and there is no research on their usage. The aim of this study was to explore how best to conceptualise such a scale’s content and usage, based on clinicians’ perceptions and experiences of current scales. Three focus groups were conducted, involving 12 participants who were either qualified or trainee CBT therapists. Transcripts were analysed using thematic analysis. Four main themes were generated: (1) The Awareness and Importance of Cognitions, (2) Factors Fuelling Therapist Cognitions, (3) Addressing Therapist Cognitions, and (4) Using the Scale. Participants thought it important to be aware of and address therapist cognitions (not underlying beliefs). Participants emphasised that therapist cognitions are not just products of the individual, but are influenced by external factors. A scale could enable therapists to do better work through reflective practice, as long as it was used not just to identify cognitions but also to support changes in therapist behaviour. A scale could also meet a perceived need for making this part of routine practice. However, participants discussed how therapists might have reservations about disclosing cognitions in this way. Recommendations for current practice, and future research developing such a scale, are made.

Key learning aims

(1)

To describe the phenomenon of therapist drift, and the contributions of therapist beliefs to this.

(2)

To explore the usage of current scales for measuring therapist beliefs.

(3)

To understand, based on therapist experience, how to address therapist beliefs in current practice using scales.
Self-Efficacy and Citizen Engagement in Development: Experimental Evidence from Tanzania
Authors: Lieberman Evan , Zhou Yang-Yang
Published: January 2021

Recent studies of efforts to increase citizen engagement in local governance through information campaigns report mixed results. We consider whether low levels of self-efficacy beliefs limit engagement, especially among poor citizens in poor countries. Citizens may be caught in an “efficacy trap” which limits their realization of better public goods provision. We describe results from a series of experimental studies conducted with over 2,200 citizens in rural Tanzania, in which we compare the effects of standard information campaigns with Validated Participation (VP), an intervention designed to socially validate citizens’ participation. We implement a staged approach to experimental research, seeking to balance ethical and cost concerns about field experimentation. In our main analyses, we find that VP did not lead to increased levels of self-efficacy or more active citizen behaviors relative to standard informational treatments. Nonetheless, we find some promising evidence for VP in a follow-up qualitative study with teachers. We conclude by discussing lessons from this research and directions for future investigation of the possible role of self-efficacy traps in development.
The Effects of Source Cues and Issue Frames During COVID-19
Authors: Case Chandler , Eddy Christopher , Hemrajani Rahul , Howell Christopher , Lyons Daniel , Sung Yu-Hsien , Connors Elizabeth C.
Published: January 2021

The health and economic outcomes of the COVID-19 pandemic will in part be determined by how effectively experts can communicate information to the public and the degree to which people follow expert recommendation. Using a survey experiment conducted in May 2020 with almost 5,000 respondents, this paper examines the effect of source cues and message frames on perceptions of information credibility in the context of COVID-19. Each health recommendation was framed by expert or nonexpert sources, was fact- or experience-based, and suggested potential gain or loss to test if either the source cue or framing of issues affected responses to the pandemic. We find no evidence that either source cue or message framing influence people’s responses – instead, respondents’ ideological predispositions, media consumption, and age explain much of the variation in survey responses, suggesting that public health messaging may face challenges from growing ideological cleavages in American politics.
A New Data‐Driven Bayesian Inversion of Fluvial Topography Clarifies the Tectonic History of the Corinth Rift and Reveals a Channel Steepness Threshold
Authors: Gallen S. F. , Fernández‐Blanco D.
Published: January 2021

Landscape evolution models that invert topography for rock uplift can improve our understanding of both tectonic and geomorphic processes when properly constrained with data. Here we present a flexible, data‐driven Bayesian approach to invert fluvial topography for tectonic and geomorphic model parameters and apply it to a case study, the uplifting footwall of the Corinth Rift, Greece. We invert transient river profiles and up‐flexed marine terraces to resolve seven unknown parameters in a regional‐to‐flexural uplift tectonic model and the stream power incision model. The best‐fit tectonic parameters are consistent with independent data and predict block uplift rates of ∼0.1 mm yr−1 that changed to flexural uplift rates of ∼1.6 mm yr−1 at ∼0.6 Ma, as the master normal fault initiated. Similarly, the best‐fit geomorphic parameters predict sediment flux consistent with the offshore record and erodibility consistent with previous studies. However, the drainage area exponent, , of ∼2, and slope exponent, , of ∼7, are unusually high, indicating a threshold channel steepness where fluvial topography is largely insensitive to rock uplift rate >0.05 mm yr−1. Analysis indicates channels narrow to accommodate enhanced uplift rates, but channel narrowing only partially explains our results, suggesting that other processes not accounted for in the generic stream power model are also relevant to bedrock river incision in Corinth. Our results help clarify the tectonic and geomorphic evolution of the Corinth Rift, have important implications for studies that invert topography for rock uplift histories, and provide insight into potential limitations of some long‐term river incision models.
Scale‐Dependent Bedform Migration and Deformation in the Physical and Spectral Domains
Authors: Lee Jiyong , Musa Mirko , Guala Michele
Published: January 2021

Multi‐scale bathymetries observed in laboratory channels and natural rivers have posed several challenges to the description of bedform geometry and kinematics. To better quantify scale‐dependent migration velocity, high resolution spatio‐temporal bed evolution data are analyzed using three independent methods: (i) a bedform tracking method that identifies individual bedforms in longitudinal bed elevation profiles, (ii) a cross‐correlation based, image matching technique in consecutive bathymetry scans similar to Particle Image Velocimetry, and (iii) two‐dimensional frequency‐wavenumber spectra marking a dispersion relation between bedform period and length, allowing estimation of Fourier‐based, scale‐dependent migration velocities. The comparative studies show that the spectral and bedform tracking methods present small differences in the migration velocity of medium‐large bedforms. However, significant deviations occur in the small bedforms, mostly due to bedform sheltering or amplified exposure to the flow, which also contribute to their enhanced scale‐dependent deformation. The analysis also shows that some form of scale separation is needed to extract the large and slowly migrating bedforms as they are masked by secondary features when several bedform orders coexist. Bathymetric Image Velocimetry reasonably estimates the averaged migration velocity and exhibits potential to study relations between spanwise bed surface velocity and local bedform kinematics.
Modeled and Observed Bedrock Displacements in North‐East Greenland Using Refined Estimates of Present‐Day Ice‐Mass Changes and Densified GNSS Measurements
Authors: Kappelsberger Maria T. , Strößenreuther Undine , Scheinert Mirko , Horwath Martin , Groh Andreas , Knöfel Christoph , Lunz Susanne , Khan Shfaqat A.
Published: January 2021

Models of the glacial‐isostatic adjustment (GIA) to past ice‐mass changes exhibit large differences in north‐east Greenland owing to insufficient knowledge about glacial history and Earth rheology. The GIA uncertainties feed back to uncertainties in present‐day mass‐balance estimates from satellite gravimetry. Geodetic Global Navigation Satellite System (GNSS) measurements allow to directly observe displacement of bedrock. We present results from repeated and continuous GNSS measurements conducted within five measurement campaigns between 2008 and 2017. We used the observed uplift rates to validate different GIA models in conjunction with estimates of the elastic response of the solid Earth to present‐day ice‐mass changes. To determine present‐day ice‐mass changes and the associated elastic deformations, we combined satellite altimetry data from CryoSat‐2 with satellite gravimetry data from the Gravity Recovery and Climate Experiment for the entire Greenland Ice Sheet (GrIS) and included peripheral glaciers and ice caps. The different GIA models were consistently used in all processing steps. The GNSS measurements in north‐east Greenland revealed uplift rates in the range of 2.8 to 8.9 mm yr−1. The comparison of the total displacement predicted by GIA and elastic modeling with the GNSS‐based displacement clearly favors GIA models that show low rates (0.7–4.4 mm yr−1 at the GNSS sites) against GIA models with higher rates of up to 8.3 mm yr−1. The correction due to the favored GIA model in north‐east Greenland results in an ice‐mass loss of 233 ± 43 Gt yr−1 for the GrIS including peripheral glaciers over the period July 2010 to June 2017.
ChinaSpec: A Network for Long‐Term Ground‐Based Measurements of Solar‐Induced Fluorescence in China
Authors: Zhang Yongguang , Zhang Qian , Liu Liangyun , Zhang Yangjian , Wang Shaoqiang , Ju Weimin , Zhou Guangsheng , Zhou Li , Tang Jianwu , Zhu Xudong , Wang Feng , Huang Ying , Zhang Zhaoying , Qiu Bo , Zhang Xiaokang , Wang Songhan , Huang Changping , Tang Xuguang , Zhang Jinsong
Published: January 2021

Remotely sensed solar‐induced fluorescence (SIF) has emerged as a novel and powerful approach for terrestrial vegetation monitoring. Continuous measurements of SIF in synergy with concurrent eddy covariance (EC) flux measurements can provide a new opportunity to advance terrestrial ecosystem science. Here, we introduce a network of ground‐based continuous SIF observations at flux tower sites across the mainland China referred to as ChinaSpec. The network consists of 16 tower sites until 2019 including six cropland sites, four grassland sites, four forest sites, and two wetland sites. An automated SIF system was deployed at each of these sites to collect continuous high‐resolution spectra for high‐frequency SIF retrievals in synergy with EC flux measurements. The goal of ChinaSpec is to provide long‐term ground‐based SIF measurements and promote the collaborations between optical remote sensing and EC flux observation communities in China. We present here the details of instrument specifications, data collection and processing procedures, data sharing and utilization protocols, and future plans. Furthermore, we show the examples how ground‐based SIF observations can be used to track vegetation photosynthesis from diurnal to seasonal scales, and to assist in the validation of fluorescence models and satellite SIF products (e.g., from OCO‐2 and TROPOMI) with the measurements from these sites since 2016. This network of SIF observations could improve our understanding of the controls on the biosphere‐atmosphere carbon exchange and enable the improvement of carbon flux predictions. It will also help integrate ground‐based SIF measurements with EC flux networks which will advance ecosystem and carbon cycle researches globally.
Sequential Abiotic‐Biotic Processes Drive Organic Carbon Transformation in Peat Bogs
Authors: Fudyma Jane D. , Toyoda Jason G. , Chu Rosalie K. , Weitz Karl K. , Heyman Heino M. , Eder Elizabeth , Hoyt David W. , Gieschen Hans , Graf Grachet Nathalia , Wilson Rachel M. , Tfaily Malak M.
Published: January 2021

Peatlands, which store one third of the terrestrial carbon (C), are subject to large disturbances under a changing climate. It is crucial to understand how microbial and physiochemical factors affect the vulnerability of these large C stores to predict climate‐induced greenhouse gas fluxes. Here, we used a combination of mass spectrometry and spectroscopy techniques, to understand sequential biotic and abiotic degradation pathways of Sphagnum fallax leachate in an anaerobic incubation experiment, in the presence and absence of microorganisms. Removal of microorganisms was carried out by passing aqueous samples through 0.2‐µm filters. Our results revealed that S. fallax leachate degradation by abiotic reactions is a significant contributor to CO2 production. Further, abiotic factors, such as low pH, are responsible for partial dissolved organic carbon (DOC) degradation that produces bioavailable compounds that shift microbial metabolic pathways and stimulate respiration in peat bogs. Acid‐catalyzed hydrolysis of Sphagnum‐ produced glycosides can provide the microbial communities with glucose and stimulate microbial respiration of DOC to CO2. These results, while unique to peatlands, demonstrate the importance and underscore the complexity of sequential abiotic and biotic processes on C cycling in peat bogs. It is therefore crucial to incorporate abiotic degradation and sequential below‐ground biotic and abiotic interactions into climate models for a better prediction of the influence of climate change on DOC stability in peatlands. These findings might not be representative of other ecosystems with different environmental conditions including mineral‐rich peatlands and plant matter in surface peat horizons that comprise discrete microbial populations, and DOC composition.
SOX2-dependent expression of dihydroorotate dehydrogenase regulates oral squamous cell carcinoma cell proliferation
Authors: Qiu Xuemei , Jiang Sheng , Xiao Yanxuan , He Yumin , Ren Tao , Jiang Lu , Liu Rui , Chen Qianming
Published: January 2021

Oral squamous cell carcinoma (OSCC) become a heavy burden of public health, with approximately 300 000 newly diagnosed cases and 145 000 deaths worldwide per year. Nucleotide metabolism fuel DNA replication and RNA synthesis, which is indispensable for cell proliferation. But how tumor cells orchestrate nucleotide metabolic enzymes to support their rapid growth is largely unknown. Here we show that expression of pyrimidine metabolic enzyme dihydroorotate dehydrogenase (DHODH) is upregulated in OSCC tissues, compared to non-cancerous adjacent tissues. Enhanced expression of DHODH is correlated with a shortened patient survival time. Inhibition of DHODH by either shRNA or selective inhibitors impairs proliferation of OSCC cells and growth of tumor xenograft. Further, loss of functional DHODH imped de novo pyrimidine synthesis, and disrupt mitochondrial respiration probably through destabilizing the MICOS complex. Mechanistic study shows that transcriptional factor SOX2 plays an important role in the upregulation of DHODH in OSCC. Our findings add to the knowledge of how cancer cells co-opt nucleotide metabolism to support their rapid growth, and thereby highlight DHODH as a potential prognostic and therapeutic target for OSCC treatment.