bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of β-Be3N2 nanocrystallites in Be-implanted GaN
Authors: Peng Yi , Saleem Muhammad Farooq , Wei Wenwang , Ji Keyu , Guo Qi , Yue Yang , Chen Jie , Zhang Xuan , Wang Yukun , Sun Wenhong
Published: February 2021

A small Be ion dose of 5 × 1014 cm−2 was implanted in a 2 μm thick GaN epilayer at an energy of 50 keV. The sample was characterized by high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy techniques after a post-implantation rapid thermal annealing (RTA) treatment. The HRTEM images show the crystallographic (1 1 0) and (0 0 2) planes of β-Be3N2. Two characteristic parallelograms drawn in Fast Fourier transform (FFT) image support the formation of β-Be3N2 nanocrystallites in RTA treated sample. Two Raman peaks at 168 and 199 cm−1 are observed in the Raman spectrum of the sample that are assigned to β-Be3N2 on the basis of group theory and HRTEM data. The Raman peak at 168 cm−1 is found close to the K point in the first Brillouin zone of β-Be3N2 while the peak at 199 cm−1 is assigned as a combination mode of the fundamental Raman modes of β-Be3N2.
Binding of SARS-CoV-2/SARS-CoV spike protein with human ACE2 receptor
Authors: Koirala Rajendra P , Thapa Bidhya , Khanal Shyam P , Powrel Jhulan , Adhikari Rajendra P , Adhikari Narayan P
Published: February 2021

SARS-CoV-2 virus is the serious health concern throughout the world. A comprehensive investigation of binding of SARS-CoV-2 active site with host receptor protein hACE2 is important in designing effective drugs. In the present work, the major amino acid binding partners between the virus CTD and host receptor have been studied and are compared with SARS-CoV RBD binding with hACE2. Our investigation show that some unique hydrogen bond pairs which were not reported in previous work. Along with hydrogen bonding, salt-bridges, hydrophobic interactions and contributions of electrostatic and van der Waals contacts play significant role in binding mechanism. The binding affinity of SARS-CoV-2 CTD/hACE2 is greater than SARS-CoV RBD/hACE2. This outcome is also verified from the free energy estimation by using umbrella sampling.
Energy regeneration from vehicle unidirectional suspension system by a non-contact piezo-magneto harvester
Authors: Alhumaid Saleh , Hess Daniel , Guldiken Rasim
Published: February 2021

Potential energy is wasted from vehicle vibration caused by road roughness. The suspension system absorbs vibration and dissipates energy in the form of heat. The dissipated energy can be recaptured into useful energy to enhance electric vehicles efficiency. This paper proposes a dual-mass unidirectional shock absorber with a piezoelectric harvester to assess the potential power that can be harvested from vibration. The regenerative suspension can be divided into two parts: transmission module and conversion module. The components of the transmission model are rack and pinion, bevel gears, planetary gearbox, shaft, and overrunning clutch that make the harvester rotates in one direction. The conventional electromagnetic model is replaced by a conversion model that consists of piezoelectric plates that are excited by magnetic forces induced by rectangular magnetic plates that are uniformly placed on an internal ring rotator and concentric external ring stator. A mathematical model is built to describe the process and calculate the power output resulting from the piezoelectric plates. The theoretical results illustrate a root mean square of output power of 16 W and 242 W can be achieved with a ring radius of 0.05 m with vehicle speed 120 km/h on good road condition and poor road condition, respectively.
NNETFIX: an artificial neural network-based denoising engine for gravitational-wave signals
Authors: Mogushi Kentaro , Quitzow-James Ryan , Cavaglià Marco , Kulkarni Sumeet , Hayes Fergus
Published: February 2021

Instrumental and environmental transient noise bursts in gravitational-wave (GW) detectors, or glitches, may impair astrophysical observations by adversely affecting the sky localization and the parameter estimation of GW signals. Denoising of detector data is especially relevant during low-latency operations because electromagnetic follow-up of candidate detections requires accurate, rapid sky localization and inference of astrophysical sources. NNETFIX is a machine learning, artificial neural network-based algorithm designed to estimate the data containing a transient GW signal with an overlapping glitch as though the glitch was absent. The sky localization calculated from the denoised data may be significantly more accurate than the sky localization obtained from the original data or by removing the portion of the data impacted by the glitch. We test NNETFIX in simulated scenarios of binary black hole coalescence signals and discuss the potential for its use in future low-latency LIGO-Virgo-KAGRA searches. In the majority of cases for signals with a high signal-to-noise ratio, we find that the overlap of the sky maps obtained with the denoised data and the original data is better than the overlap of the sky maps obtained with the original data and the data with the glitch removed.
Direct and indirect regulation of Pom1 cell size pathway by the protein phosphatase 2C Ptc1
Authors: Gerganova Veneta , Bhatia Payal , Vincenzetti Vincent , Martin Sophie G.
Published: February 2021

This article probes the function of the type 2C phosphatase Ptc1 and shows it participates in cell size regulation through the Pom1 kinase. Ptc1 can dephosphorylate Pom1 but modulates its localization indirectly, indicating direct and indirect roles of this protein phosphatase.
Dispersal Mechanism Assessment forPanonychus citri(Acari: Tetranychidae) Secondary Outbreaks
Authors: Qayyoum Muhammad Asif , Song Zi-Wei , Zhang Bao-Xin , Li Dun-Song
Published: February 2021

Secondary population outbreaks of Panonychus citri (McGregor) (Acari: Tetranychidae) are triggered by synthetic chemical applications (dose and method), which also elicited a change in mites’ behavioral responses. This study aimed to understand the dispersal pattern of P. citri and how changes in dispersal behavior may influence secondary pest outbreaks in the field with or without chemicals. We found positive density and time-dependent dispersal within the inoculated leaflet. Dispersion from inoculated leaflets to the last leaflet depends on initial density and time. A significant difference was observed in the composite dispersal index data and preferred midrib region. The minimum dispersal was observed by P. citri in no direct contact with treated surfaces, whereas attraction was observed on treated surfaces (right). All chemicals gave different dispersal and feed disruption responses depending on the treatment application pattern. The maximum number of mites dispersed and avoid surfaces treated with abamectin and vegetable oil, respectively. Vegetable and EnSpray 99 had a positive impact on toxicity, repellency, and irritancy. The fecundity rate of P. citri boosted with a high dose and direct exposure. Panonychus citri colonization as a single individual or gregarious distribution resulted in a rapid fecundity rate, which may explain why citrus orchards were severely damaged and how suddenly a whole citrus plantation can be highly infested. This study concluded that change in treatment application patterns leads to a change in the behavioral responses in P. citri.
We All Need Philosophy Of Science: Analyticism As A Vehicle For Explanatory Understanding In Multi-method Research
Authors: Okpotor Faith I
Published: February 2021

Explaining and Understanding are considered mutually exclusive in political research. In this view, Explaining involves making observations as an outsider, with emphasis on causal laws, generalizations, and predictions. Conversely, Understanding occurs from the inside, with emphasis on meaning-making. This research note addresses Explaining, Understanding, and the related concept of reflexivity in multi-method/mixed-method research involving fieldwork. Rather than taking for granted the dichotomy between Explaining and Understanding that stems from Cartesian anxiety, I argue for the non-mutually exclusive alternative of ‘explanatory understanding’ and propose analyticism as the appropriate methodological path. An analyticist methodology involves creating a model that is a general account of a phenomenon, which is then used in case-specific analytical narratives to reveal departures from the model. Since understanding requires adequate explanation, explanatory understanding helps us better make sense of the world. Therefore, Explaining and Understanding are not merely oppositional stances between identifying causes and making sense. We cannot identify causes without making sense, and making sense involves a degree of causal inference. Explanatory understanding also necessitates reflexivity, which I conceptualize as methodological and personal positionality. I apply these arguments to my study of post-election violence in West Africa, drawing on fieldwork experience in Ghana, Nigeria, and Côte d’Ivoire.
Guidance on the treatment of antipsychotic-induced hyperprolactinemia when switching the antipsychotic is not an option
Authors: Rusgis Matthew M , Alabbasi Afaq Y , Nelson Leigh Anne
Published: February 2021

Purpose

This article aims to evaluate management options for antipsychotic-induced hyperprolactinemia and associated treatment considerations such as efficacy, tolerability, drug interactions, contraindications, and dosing regimens.

Hyperprolactinemia is a common adverse effect of antipsychotics. First-line management includes reducing the dose of the offending antipsychotic, discontinuing the antipsychotic, or switching to another antipsychotic associated with a lower risk of hyperprolactinemia. However, these options are not always practical and are associated with a risk of relapse of the psychiatric illness. Other management options include adjunctive aripiprazole, dopamine agonists (cabergoline and bromocriptine), metformin, and herbal supplements. A search of Embase, PubMed, and Google Scholar using key terms such as hyperprolactinemia, prolactin, antipsychotic, treatment guidelines, aripiprazole, dopamine agonist, cabergoline, bromocriptine, metformin, herbals, supplements, and medications was conducted for literature retrieval. Upon evaluation of the available literature we found the following: (1) aripiprazole is safe and effective in lowering prolactin levels within normal limits; (2) adjunctive cabergoline and bromocriptine decrease elevated prolactin levels, while cabergoline may be more effective in reducing prolactin but can also be associated with a more serious adverse effect of cardiac valvular abnormalities; (3) metformin causes a mild reduction of prolactin levels; and (4) there are limited data to support use of herbal medications (chamomile, Peony-Glycyrrhiza decoction, and shakuyaku-kanzo-to) in antipsychotic-induced hyperprolactinemia

Conclusion

There are treatments available for antipsychotic-induced hyperprolactinemia in patients who are unable to alter their current antipsychotic regimen. However, there remains a need for additional short- and long-term studies to determine the efficacy and safety of these treatment strategies, given that patients taking antipsychotics typically require chronic, life-long treatment for their illnesses.
Co-ordination between xylem anatomy, plant architecture and leaf functional traits in response to abiotic and biotic drivers in a nurse cushion plant
Authors: García-Cervigón Ana I , García-López María A , Pistón Nuria , Pugnaire Francisco I , Olano José Miguel
Published: February 2021

Background and Aims

Plants in dry Mediterranean mountains experience a double climatic stress: at low elevations, high temperatures coincide with water shortage during summer, while at high elevations temperature decreases and water availability increases. Cushion plants often act as nurses by improving the microclimate underneath their canopies, hosting beneficiary species that may reciprocally modify their benefactors’ microenvironment. We assess how the nurse cushion plant Arenaria tetraquetra subsp. amabilis adjusts its hydraulic system to face these complex abiotic and biotic constraints.

Methods

We evaluated intra-specific variation and co-ordination of stem xylem anatomy, leaf functional traits and plant architecture in response to elevation, aspect and the presence of beneficiary species in four A. tetraquetra subsp. amabilis populations in the Sierra Nevada mountains, southern Spain.

Key Results

Xylem anatomical and plant architectural traits were the most responsive to environmental conditions, showing the highest mutual co-ordination. Cushions were more compact and had smaller, more isolated conductive vessels in the southern than in the northern aspect, which allow minimization of the negative impacts of more intense drought. Only vessel size, leaf mass per area and terminal branch length varied with elevation. Nurse cushions co-ordinated plant architecture and xylem traits, having higher canopy compactness, fewer leaves per branch and fewer, more isolated vessels than non-nurse cushions, which reflects the negative effects of beneficiary plants on nurse water status. In non-nurse cushions, plant architecture co-ordinated with leaf traits instead. The interacting effects of aspect and elevation on xylem traits showed that stress due to frost at high elevation constrained xylem anatomy in the north, whereas stress due to drought had a parallel effect in the south.

Conclusions

Trait co-ordination was weaker under more demanding environmental conditions, which agrees with the hypothesis that trait independence allows plants to better optimize different functions, probably entailing higher adjustment potential against future environmental changes.
WDNE: an integrative graphical model for inferring differential networks from multi-platform gene expression data with missing values
Authors: Ou-Yang Le , Cai Dehan , Zhang Xiao-Fei , Yan Hong
Published: February 2021

The mechanisms controlling biological process, such as the development of disease or cell differentiation, can be investigated by examining changes in the networks of gene dependencies between states in the process. High-throughput experimental methods, like microarray and RNA sequencing, have been widely used to gather gene expression data, which paves the way to infer gene dependencies based on computational methods. However, most differential network analysis methods are designed to deal with fully observed data, but missing values, such as the dropout events in single-cell RNA-sequencing data, are frequent. New methods are needed to take account of these missing values. Moreover, since the changes of gene dependencies may be driven by certain perturbed genes, considering the changes in gene expression levels may promote the identification of gene network rewiring. In this study, a novel weighted differential network estimation (WDNE) model is proposed to handle multi-platform gene expression data with missing values and take account of changes in gene expression levels. Simulation studies demonstrate that WDNE outperforms state-of-the-art differential network estimation methods. When applied WDNE to infer differential gene networks associated with drug resistance in ovarian tumors, cell differentiation and breast tumor heterogeneity, the hub genes in the estimated differential gene networks can provide important insights into the underlying mechanisms. Furthermore, a Matlab toolbox, differential network analysis toolbox, was developed to implement the WDNE model and visualize the estimated differential networks.
Mesoamerica is a cradle and the Atlantic Forest is a museum of Neotropical butterfly diversity: insights from the evolution and biogeography of Brassolini (Lepidoptera: Nymphalidae)
Authors: Matos-Maraví Pável , Wahlberg Niklas , Freitas André V L , Devries Phil , Antonelli Alexandre , Penz Carla M
Published: February 2021

Regional species diversity is explained ultimately by speciation, extinction and dispersal. Here, we estimate dispersal and speciation rates of Neotropical butterflies to propose an explanation for the distribution and diversity of extant species. We focused on the tribe Brassolini (owl butterflies and allies), a Neotropical group that comprises 17 genera and 108 species, most of them endemic to rainforest biomes. We inferred a robust species tree using the multispecies coalescent framework and a dataset including molecular and morphological characters. This formed the basis for three changes in Brassolini classification: (1) Naropina syn. nov. is subsumed within Brassolina; (2) Aponarope syn. nov. is subsumed within Narope; and (3) Selenophanes orgetorix comb. nov. is reassigned from Catoblepia to Selenophanes. By applying biogeographical stochastic mapping, we found contrasting species diversification and dispersal dynamics across rainforest biomes, which might be explained, in part, by the geological and environmental history of each bioregion. Our results revealed a mosaic of biome-specific evolutionary histories within the Neotropics, where butterfly species have diversified rapidly (cradles: Mesoamerica), have accumulated gradually (museums: Atlantic Forest) or have diversified and accumulated alternately (Amazonia). Our study contributes evidence from a major butterfly lineage that the Neotropics are a museum and a cradle of species diversity.
An Expanded Framework for Community Viability Analysis
Authors: Eichenwald Adam J , Reed J Michael
Published: February 2021

Community viability analysis (CVA) has been put forth as an analogue for population viability analysis (PVA), an accepted conservation tool for evaluating species-specific threat and management scenarios. The original proposal recommended that CVAs examine resistance-based questions. PVAs, however, are broadly applicable to multiple types of viability questions, suggesting that the original CVA definition may be too narrow. In the present article, we advance an expanded framework in which CVA includes any analysis assessing the status, threats, or management options of an ecological community. We discuss viability questions that can be investigated with CVA. We group those inquiries into categories of resistance, resilience, and persistence, and provide case studies for each. Finally, we broadly present the steps in a CVA.
Health economic analysis of total extraperitoneal repair versus Lichtenstein surgery for inguinal hernia: data from a randomized clinical trial
Authors: Westin L , Sandblom G , Gunnarsson U , Dahlstrand U
Published: February 2021

Background

The aim was to compare cost-effectiveness of Lichtenstein under local anaesthesia (LLA) with total extraperitoneal repair (TEP) under general anaesthesia for primary inguinal hernia in men. An endoscopic approach to inguinal hernia repair is often considered costlier. The cost of endoscopic hernia repair, however, has not been compared to open inguinal hernia repair in a cost-effective setting.

Methods

Data from an RCT comparing TEP and Lichtenstein in a cost-effective setting, with health economy as a secondary endpoint, were used. Data on costs were collected prospectively. Data on sick leave were obtained from the Swedish Social Insurance Agency in order to compare lengths of sick leave.

Results

In total, 384 patients were included and 374 (97.4 per cent) patients were available for analysis, 189 in the LLA group and 185 in the TEP group. The median operating time for LLA was 70 (i.q.r. 60–80) min compared with 60 (i.q.r. 50–75) min in the TEP group (P < 0.001). The median time in operating theatre was 114 (i.q.r. 95–-125) min for LLA and 125 (i.q.r. 110–145) min for TEP (P < 0.001). The median cost including all materials was 2433 (i.q.r. 2084–2734) Euros for LLA and 2395 (i.q.r. 2093–2784) Euro for TEP (P = 0.650). Mean sick leave was 4.2 days in the LLA group and 6.2 days in the TEP group (P = 0.830).

Conclusion

The overall cost to the hospital or length of sick leave did not differ between LLA and TEP.
LRRK2 G2019S kinase activity triggers neurotoxic NSF aggregation
Authors: Pischedda Francesca , Cirnaru Maria Daniela , Ponzoni Luisa , Sandre Michele , Biosa Alice , Carrion Maria Perez , Marin Oriano , Morari Michele , Pan Lifeng , Greggio Elisa , Bandopadhyay Rina , Sala Mariaelvina , Piccoli Giovanni
Published: February 2021

Parkinson’s disease is characterized by the progressive degeneration of dopaminergic neurons within the substantia nigra pars compacta and the presence of protein aggregates in surviving neurons. The LRRK2 G2019S mutation is one of the major determinants of familial Parkinson’s disease cases and leads to late-onset Parkinson’s disease with pleomorphic pathology, including α-synuclein accumulation and deposition of protein inclusions. We demonstrated that LRRK2 phosphorylates N-ethylmaleimide sensitive factor (NSF). We observed aggregates containing NSF in basal ganglia specimens from patients with Parkinson’s disease carrying the G2019S variant, and in cellular and animal models expressing the LRRK2 G2019S variant. We found that LRRK2 G2019S kinase activity induces the accumulation of NSF in toxic aggregates. Of note, the induction of autophagy cleared NSF aggregation and rescued motor and cognitive impairment observed in aged hG2019S bacterial artificial chromosome (BAC) mice. We suggest that LRRK2 G2019S pathological phosphorylation impacts on NSF biochemical properties, thus causing the formation of cytotoxic protein inclusions.
Reconstructing the Evolutionary History of a Highly Conserved Operon Cluster inGammaproteobacteriaandBacilli
Authors: Brandis Gerrit
Published: February 2021

The evolution of gene order rearrangements within bacterial chromosomes is a fast process. Closely related species can have almost no conservation in long-range gene order. A prominent exception to this rule is a >40 kb long cluster of five core operons (secE-rpoBC-str-S10-spc-alpha) and three variable adjacent operons (cysS, tufB, and ecf) that together contain 57 genes of the transcriptional and translational machinery. Previous studies have indicated that at least part of this operon cluster might have been present in the last common ancestor of bacteria and archaea. Using 204 whole genome sequences, ∼2 Gy of evolution of the operon cluster were reconstructed back to the last common ancestors of the Gammaproteobacteria and of the Bacilli. A total of 163 independent evolutionary events were identified in which the operon cluster was altered. Further examination showed that the process of disconnecting two operons generally follows the same pattern. Initially, a small number of genes is inserted between the operons breaking the concatenation followed by a second event that fully disconnects the operons. While there is a general trend for loss of gene synteny over time, there are examples of increased alteration rates at specific branch points or within specific bacterial orders. This indicates the recurrence of relaxed selection on the gene order within bacterial chromosomes. The analysis of the alternation events indicates that segmental genome duplications and/or transposon-directed recombination play a crucial role in rearrangements of the operon cluster.
A combined method using singular spectrum analysis and instantaneous frequency for the ground-roll filtering
Authors: Possidonio Misael , Porsani Milton J
Published: February 2021

The noise attenuation is a fundamental step in seismic data processing, especially when ground-roll suppression remains a challenge. Rank-reduction methods have become quite popular in recent decades, as they promote significant improvements in the quality of data, highlighting reflections in seismograms. We present a methodology for ground-roll filtering, which combines the application of a recursive-iterative singular spectrum analysis method, in the time domain, as a particular way to decompose seismic data, with the computation of the average instantaneous frequency of the signal components. This combination allows for a precise estimation and filtering of the ground-roll noise. The frequency values are used for determining, in each component, the low-frequency parts associated with the ground roll. For every single component, the ground roll is attenuated by zeroing, and stacking the data components, where the average instantaneous frequency values match the ground-roll bandwidth of frequency. Also, in order to enhance the lateral coherence of the reflectors, we present an extension of the recursive-iterative algorithm for a multichannel case. The multichannel algorithm is applicable on a shot, or common mid-point family of seismic traces, after the normal moveout correction. The numerical results using real data show the effectiveness of the proposed methodology for ground-roll attenuation and for improving the velocity analysis.
Modelling the large earthquakes recurrence times along the North Aegean Trough Fault Zone (Greece) with a physics-based simulator
Authors: Kourouklas Christos , Console Rodolfo , Papadimitriou Eleftheria , Murru Maura , Karakostas Vassilios
Published: February 2021

The recurrence time of large earthquakes above a predefined magnitude threshold on specific faults or fault segments is one of the key parameters for the development of long-term Earthquake Rupture Forecast models. Observational data of successive large earthquakes per fault segment are often limited and thus inadequate for the construction of robust statistical models. The physics-based earthquake simulators are a powerful tool to overcome recurrence data limitations by generating long earthquake records. A physics-based simulator, embodying well known physical processes, is applied in the North Aegean Trough (NAT) Fault Zone (Greece). The application of the simulation is implemented, after defining a five segment source model, aiming at the investigation of the recurrence behaviour of earthquakes with Mw ≥ 6.5 and Mw ≥ 7.0. The detailed examination of the 544 Mw ≥ 6.5 earthquakes included in the simulated catalogue reveals that both single and multiple segmented ruptures can be realized along the NAT. Results of statistical analysis of the interevent times of Mw ≥ 6.5 and Mw≥ 7.0 earthquakes per participating segment to the related ruptures indicate the better performance of the Brownian Passage Time renewal model in comparison to exponential model. These results provide evidence for quasi-periodic recurrence behaviour, agreeing with the elastic rebound theory, instead of Poissonian behaviour.
Blockchain as Schumpeter Mark 1 or Mark 2? An empirical analysis of blockchain job offers in France and Germany
Authors: Cimiterra Martin , Krafft Jackie , Nesta Lionel
Published: February 2021

This article investigates whether blockchain technology corresponds to Schumpeter Mark 1 or Mark 2 industrial dynamics. Using an original database of 385 job offers in three different domains, namely, blockchain, biotechnology, and storekeeping, posted by 285 companies in France and Germany in early 2019, we explore whether the usual Schumpeter Mark 1 and 2 attributes apply to blockchains. We use ordered multinomial probit models to explain the level of work experience demanded by companies. To our knowledge, this contribution is one among very few attempts to identify the main features of blockchain industrial dynamics.
Genetic risk scores for cardiometabolic traits in sub-Saharan African populations
Authors: Ekoru Kenneth , Adeyemo Adebowale A , Chen Guanjie , Doumatey Ayo P , Zhou Jie , Bentley Amy R , Shriner Daniel , Rotimi Charles N
Published: February 2021

Background

There is growing support for the use of genetic risk scores (GRS) in routine clinical settings. Due to the limited diversity of current genomic discovery samples, there are concerns that the predictive power of GRS will be limited in non-European ancestry populations. GRS for cardiometabolic traits were evaluated in sub-Saharan Africans in comparison with African Americans and European Americans.

Methods

We evaluated the predictive utility of GRS for 12 cardiometabolic traits in sub-Saharan Africans (AF; n = 5200), African Americans (AA; n = 9139) and European Americans (EUR; n = 9594). GRS were constructed as weighted sums of the number of risk alleles. Predictive utility was assessed using the additional phenotypic variance explained and the increase in discriminatory ability over traditional risk factors [age, sex and body mass index (BMI)], with adjustment for ancestry-derived principal components.

Results

Across all traits, GRS showed up to a 5-fold and 20-fold greater predictive utility in EUR relative to AA and AF, respectively. Predictive utility was most consistent for lipid traits, with percentage increase in explained variation attributable to GRS ranging from 10.6% to 127.1% among EUR, 26.6% to 65.8% among AA and 2.4% to 37.5% among AF. These differences were recapitulated in the discriminatory power, whereby the predictive utility of GRS was 4-fold greater in EUR relative to AA and up to 44-fold greater in EUR relative to AF. Obesity and blood pressure traits showed a similar pattern of greater predictive utility among EUR.

Conclusions

This work demonstrates the poorer performance of GRS in AF and highlights the need to improve representation of multiple ethnic populations in genomic studies to ensure equitable clinical translation of GRS.
Physical activity and the risk of rheumatoid arthritis: evidence from meta-analysis and Mendelian randomization
Authors: Sun Lingling , Zhu Jiahao , Ling Yuxiao , Mi Shuai , Li Yasong , Wang Tianle , Li Yingjun
Published: February 2021

Background

There is very little information about the association between physical activity (PA) and the risk of rheumatoid arthritis (RA). The purpose of this study is to understand the effect of PA on subsequent risk of developing RA.

Methods

A literature search was performed in PubMed and Web of Science up to 19 September 2020. Observational studies examining associations between PA and the RA development were identified. Categorical and dose–response meta-analyses were both performed. Then two-sample Mendelian randomization (MR) analysis was conducted to interrogate the causal relationship by utilizing genetic instruments identified from a genome-wide association study of self-reported and accelerometer-based PA traits.

Results

Four eligible studies were included in the meta-analyses, involving 4213 RA cases among 255 365 participants. The summary relative risk (RR) of RA risk was 0.79 [95% confidence interval (CI): 0.72, 0.87] for the highest vs the lowest PA, and 0.85 (95% CI: 0.79, 0.92) for PA vs inactivity/occasional PA. However, we found no convincing evidence supporting a causal role of genetically predicted accelerometer-measured PA [odds ratio (OR): 0.97; 95% CI: 0.88, 1.08 per 1-SD unit increment], genetically predicted moderate-to-vigorous PA (OR: 1.08; 95% CI: 0.49, 2.39 per 1-SD unit increment) or genetically predicted vigorous PA ≥3 days/week (OR: 2.63; 95% CI: 0.05, 130.96) with RA risk.

Conclusions

The meta-analyses of the observational studies indicated that higher PA levels correlate with reduced risk of RA. In contrast to meta-analyses, the MR analyses reported here suggested PA may not help to prevent RA.
Segment Inequality and Almost Rigidity Structures for Integral Ricci Curvature
Authors: Chen Lina
Published: February 2021

We will show the Cheeger–Colding segment inequality for manifolds with integral Ricci curvature bound. By using this segment inequality, the almost rigidity structure results for integral Ricci curvature will be derived by a similar method as in [1]. And the sharp Hölder continuity result of [7] holds in the limit space of manifolds with integral Ricci curvature bound.
ASAS-NANP symposium: digestion kinetics in pigs: the next step in feed evaluation and a ready-to-use modeling exercise
Authors: Gerrits Walter J J , Schop Marijke T A , de Vries Sonja , Dijkstra Jan
Published: February 2021

Growing importance of upcycling agricultural by-products, food waste, and food processing by-products through livestock production strongly increased the variation in the nutritional quality of feed ingredients. Traditionally, feed ingredients are evaluated based on their measured extent of digestion. Awareness increases that in addition to the extent, the kinetics of digestion affects the metabolic fate of nutrients after absorption. Together with a growing body of evidence of complex interactions occurring within the lumen of the digestive tract, this urges the need of developing new approaches for feed evaluation. In a recently developed approach, we propose combining in vitro and in silico methods for feed ingredient evaluation. First steps in the development of such a systems were made by (1) evaluating in vitro the digestion potential of feed ingredients, regarding this as true ingredient properties and (2) predicting in silico the digestive processes like digesta transit, nutrient hydrolysis and absorption using dynamic, mechanistic modeling. This approach allows to evaluate to what extent the digestion potential of each ingredient is exploited in the digestive tract. Future efforts should focus on modeling digesta physicochemical properties and transit, applying in vitro digestion kinetic data of feed ingredients in mechanistic models, and generating reliable in vivo data on nutrient absorption kinetics across feed ingredients. The dynamic modeling approach is illustrated by a description of a modeling exercise that can be used for teaching purposes in digestive physiology or animal nutrition courses. A complete set of equations is provided as an on-line supplement, and can be built in modeling software that is freely available. Alternatively, the model can be constructed using any modeling software that enables the use of numerical integration methods.
Judicial Interactions and Human Rights Contestations in Latin America
Authors: Contesse Jorge
Published: February 2021

The Inter-American Court of Human Rights is one of the world's most active human rights tribunals. Through an impressive history of case law, the Court has exerted significant influence upon Latin American states. In recent years, however, states and domestic national courts have challenged the Inter-American Court's authority in more complex and potentially more damaging ways than in the past. By exploring how the Inter-American Court of Human Rights has expanded its reach upon states, and how states engage in turn, the Article examines ways of interaction that can enhance or debilitate the Court's authority and influence on states. The Article explores recent dissents as a potential mode of resistance, especially when coupled with states' unease towards international adjudication and suggests ways in which the Court may respond to such challenges in order to protect and enhance its authority.
Guaranteeing Admissibility of Abstract Argumentation Frameworks with Rationality and Feasibility Constraints
Authors: Chen Weiwei
Published: February 2021

This paper considers the problem of under what circumstances an aggregation rule guarantees admissible sets of arguments that represent a good compromise between several extensions, i.e., sets of arguments of abstract argumentation frameworks each provided by a different individual. We start by showing that the preservation results of Dung’s admissibility, graded admissibility and strong admissibility during the aggregation of extensions are negative. To overcome such negative results, we define a model for extension aggregation that clearly separates the constraint supposed to be satisfied by individuals and the constraint that must be met by the collective decision. Using this model, we show that the majority rule guarantees admissible sets on profiles that satisfy a variant of Dung’s admissibility, as well as profiles of extensions with some specific characteristics.
Simulating the formation of η Carinae’s surrounding nebula through unstable triple evolution and stellar merger-induced eruption
Authors: Hirai Ryosuke , Podsiadlowski Philipp , Owocki Stanley P , Schneider Fabian R N , Smith Nathan
Published: February 2021

η Carinae is an extraordinary massive star famous for its 19th century Great Eruption and the surrounding Homunculus nebula ejected in that event. The cause of this eruption has been the centre of a long-standing mystery. Recent observations, including light-echo spectra of the eruption, suggest that it most likely resulted from a stellar merger in an unstable triple system. Here we present a detailed set of theoretical calculations for this scenario; from the dynamics of unstable triple systems and the mass ejection from close binary encounters, to the mass outflow from the eruption caused by the stellar merger and the post-merger wind phase. In our model the bipolar post-merger wind is the primary agent for creating the Homunculus, as it sweeps up external eruption ejecta into a thin shell. Our simulations reproduce many of the key aspects of the shape and kinematics of both the Homunculus nebula and its complex surrounding structure, providing strong support for the merger-in-a-triple scenario.
A SAMI and MaNGA view on the stellar kinematics of galaxies on the star-forming main sequence
Authors: Fraser-McKelvie A , Cortese L , van de Sande J , Bryant J J , Catinella B , Colless M , Croom S M , Groves B , Medling A M , Scott N , Sweet S M , Bland-Hawthorn J , Goodwin M , Lawrence J , Lorente N , Owers M S , Richards S N
Published: February 2021

Galaxy internal structure growth has long been accused of inhibiting star formation in disc galaxies. We investigate the potential physical connection between the growth of dispersion-supported stellar structures (e.g. classical bulges) and the position of galaxies on the star-forming main sequence at z ∼ 0. Combining the might of the SAMI and MaNGA galaxy surveys, we measure the λRe spin parameter for 3289 galaxies over $9.5 \lt \log M_{\star } [\rm {M}_{\odot }] \lt 12$. At all stellar masses, galaxies at the locus of the main sequence possess λRe values indicative of intrinsically flattened discs. However, above $\log M_{\star }[\rm {M}_{\odot }]\sim 10.5$ where the main sequence starts bending, we find tantalizing evidence for an increase in the number of galaxies with dispersion-supported structures, perhaps suggesting a connection between bulges and the bending of the main sequence. Moving above the main sequence, we see no evidence of any change in the typical spin parameter in galaxies once gravitationally interacting systems are excluded from the sample. Similarly, up to 1 dex below the main sequence, λRe remains roughly constant and only at very high stellar masses ($\log M_{\star }[\rm {M}_{\odot }]\gt 11$), do we see a rapid decrease in λRe once galaxies decline in star formation activity. If this trend is confirmed, it would be indicative of different quenching mechanisms acting on high- and low-mass galaxies. The results suggest that whilst a population of galaxies possessing some dispersion-supported structure is already present on the star-forming main sequence, further growth would be required after the galaxy has quenched to match the kinematic properties observed in passive galaxies at z ∼ 0.
The stellar distribution function and local vertical potential from Gaia DR2
Authors: Li Haochuan , Widrow Lawrence M
Published: February 2021

We develop a novel method to simultaneously determine the vertical potential, force, and stellar z−vz phase space distribution function (DF) in our local patch of the Galaxy. We assume that the Solar Neighbourhood can be treated as a one-dimensional (1D) system in dynamical equilibrium and directly fit the number density in the z−vz plane to what we call the rational linear distribution function (RLDF) model. This model can be regarded as a continuous sum of isothermal DFs though it has only one more parameter than the isothermal model. We apply our method to a sample of giant stars from Gaia Data Release 2 and show that the RLDF provides an excellent fit to the data. The well-known phase space spiral emerges in the residual map of the z−vz plane. We use the best-fitting potential to plot the residuals in terms of the frequency and angle of vertical oscillations and show that the spiral maps into a straight line. From its slope, we estimate that the phase spirals were generated by a perturbation ∼540 Myr years ago. We also determine the differential surface density as a function of vertical velocity dispersion, a.k.a. the vertical temperature distribution. The result is qualitatively similar to what was previously found for SDSS/SEGUE G dwarfs. Finally, we address parameter degeneracies and the validity of the 1D approximation. Particularly, the mid-plane density derived from a cold sub-sample, where the 1D approximation is more secure, is closer to literature values than that derived from the sample as a whole.
Non-equilibrium ionization and radiative transport in an evolving supernova remnant
Authors: Sarkar Kartick C , Gnat Orly , Sternberg Amiel
Published: February 2021

We present numerical simulations of the evolution of a supernova (SN) remnant expanding into a uniform background medium with density $n_\mathrm{ H} = 1.0\, \mbox{ cm}^{-3}$ and temperature of 104 K. We include a dynamically evolving non-equilibrium ionization (NEI) network (consisting of all the ions of H, He, C, N, O, Ne, Mg, Si, S, Fe), frequency dependent radiation transfer (RT), thermal conduction, and a simple dust evolution model, all intra-coupled to each other and to the hydrodynamics. We assume spherical symmetry. Photoionization, radiation losses, photo-heating, charge-exchange heating/cooling, and radiation pressure are calculated on the fly depending on the local radiation field and ion fractions. We find that the dynamics and energetics (but not the emission spectra) of the SN remnants can be well modelled by collisional equilibrium cooling curves even in the absence of non-equilibrium cooling and radiative transport. We find that the effect of precursor ionizing radiation at different stages of SN remnant are dominated by rapid cooling of the shock and differ from steady-state shocks. The predicted column densities of different ions such as N+, C3+, and N4+, can be higher by up to several orders of magnitude compared to steady-state shocks. We also present some high-resolution emission spectra that can be compared with the observed remnants to obtain important information about the physical and chemical states of the remnant, as well as constrain the background interstellar medium.
Determination of strewn fields for meteorite falls
Authors: Moilanen Jarmo , Gritsevich Maria , Lyytinen Esko
Published: February 2021

When an object enters the atmosphere it may be detected as a meteor. A bright meteor, called a fireball, may be a sign of a meteorite fall. Instrumentally observed meteorite falls provide unique opportunities to recover and analyse unweathered planetary samples supplemented with the knowledge on the Solar system orbit they had. To recover a meteorite from a fireball event, it is essential that recovery teams can be directed to a well-defined search area. Until recently, simulations showing the realistic mapping of a strewn field were difficult, in particular due to the large number of unknowns not directly retrieved from the fireball observations. These unknowns include the number of fragments and their aerodynamic properties, for which the masses of the fragments need to be assumed in a traditional approach. Here, we describe a new Monte Carlo model, which has already successfully assisted in several meteorite recoveries. The model is the first of its kind as it provides an adequate representation of the processes occurring during the luminous trajectory coupled together with the dark flight. In particular, the model comprises a novel approach to fragmentation modelling that leads to a realistic fragment mass distribution on the ground. We present strewn field simulations for the well-documented Košice and Neuschwanstein meteorite falls, which demonstrate good matches to the observations. We foresee that our model can be used to revise the flux of extra-terrestrial matter onto the Earth, as it provides a possibility of estimating the terminal mass of meteorite fragments reaching the ground.
Gaia EDR3 in 6D: searching for unbound stars in the galaxy
Authors: Marchetti Tommaso
Published: February 2021

The early third data release (EDR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, and proper motions for ∼1.47 billion sources in our Milky Way, based on 34 months of observations. The combination of Gaia DR2 radial velocities with the more precise and accurate astrometry provided by Gaia EDR3 makes the best data set available to search for the fastest nearby stars in our Galaxy. We compute the velocity distribution of ∼7 million stars with precise parallaxes, to investigate the high-velocity tail of the velocity distribution of stars in the Milky Way. We release a catalogue with distances, total velocities, and corresponding uncertainties for all the stars considered in our analysis1. By applying quality cuts on the Gaia astrometry and radial velocities, we identify a clean subset of 94 stars with a probability $P_\mathrm{ub}\gt 50 {{\ \rm per\ cent}}$ to be unbound from our Galaxy. In total, 17 of these have $P_\mathrm{ub}\gt 80{{\ \rm per\ cent}}$ and are our best candidates. We propagate these stars in the Galactic potential to characterize their orbits. We find that 11 stars are consistent with being ejected from the Galactic disc, and are possible hyper-runaway star candidates. The other six stars are not consistent with coming from a known star-forming region. We investigate the effect of adopting a parallax zero-point correction, which strongly impacts our results: when applying this correction, we identify only 12 stars with $P_\mathrm{ub}\gt 50{{\ \rm per\ cent}}$, 3 of these having $P_\mathrm{ub}\gt 80{{\ \rm per\ cent}}$. Spectroscopic follow-ups with ground-based telescopes are needed to confirm the candidates identified in this work.
At your ‘online’ service! A continuous service-learning program for college students during the COVID-19 pandemic
Authors: Vicente Niku E , Moredo Peter Jayson A , Cordero Dalmacito A
Published: February 2021

School health protocols in conducting face-to-face classes must be planned carefully to ensure that students will be safe from the effects of COVID-19. This is what the authors emphasized in a recent correspondence, which we re-echo in this paper in case the situation permits. However, a greater consideration must be given to colleges and universities where the aspect of community/social engagement of the students is already part of the curriculum. There is still a greater risk for students to go to the communities for service and social interaction. With this, we suggest that the service program can still continue through an enhanced electronic service-learning, which maximizes the human resources’ capacity and highlights students’ creativity with equally useful projects.