bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactivity in social scientific experiments: what is it and how is it different (and worse) than a Placebo effect?
Authors: Jiménez-Buedo María
Published: April 2021

Reactivity, or the phenomenon by which subjects tend to modify their behavior in virtue of their being studied upon, is often cited as one of the most important difficulties involved in social scientific experiments, and yet, there is to date a persistent conceptual muddle when dealing with the many dimensions of reactivity. This paper offers a conceptual framework for reactivity that draws on an interventionist approach to causality. The framework allows us to offer an unambiguous definition of reactivity and distinguishes it from placebo effects. Further, it allows us to distinguish between benign and malignant forms of the phenomenon, depending on whether reactivity constitutes a danger to the validity of the causal inferences drawn from experimental data.
Characterizing devolatilized wood pellets for fluidized bed applications
Authors: Jarolin Kolja , Wang Shen , Dymala Timo , Song Tao , Heinrich Stefan , Shen Laihong , Dosta Maksym
Published: April 2021

We investigated devolatilized wood pellets to characterize their mechanical behavior and their microstructure. The work’s aim is to increase the understanding and modeling capabilities for the application in fluidized bed gasification as a sustainable alternative to generate synthesis gas. Our experiments showed that devolatilized wood pellets are a stable but highly porous and fragile structure. Computed tomographic images of the same pellets before and after devolatilization showed that the existing pore network in raw conditions characterizes the final structure. Along with the pores, the reaction rate likely increases and the pores massively enlarge, and internal cavities are formed. The resulting pore network dominates the mechanical behavior and leads to micro fragmentations already at low static loads or slow dynamic impacts. This results in the creation of fines or breakage already at low impact velocities. For fluidized bed devolatilization, the large-scale open pore network of the biochar pellets allows the penetration of bed material into the pellet leading to an estimated increase in the pellet’s mass of up to 45%. However, an increase in pore size caused by the penetration was not apparent. Due to the pellet’s porous structure, breakage and attrition induced by mechanical stresses are likely to be as or even more important than primary fragmentation caused by the devolatilization process itself in a reactor.
Effects of Regular Physical Activity on the Immune System, Vaccination and Risk of Community-Acquired Infectious Disease in the General Population: Systematic Review and Meta-Analysis
Authors: Chastin Sebastien F. M. , Abaraogu Ukachukwu , Bourgois Jan G. , Dall Philippa M. , Darnborough Jennifer , Duncan Elaine , Dumortier Jasmien , Pavón David Jiménez , McParland Joanna , Roberts Nicola J. , Hamer Mark
Published: April 2021

Background

Regular physical activity is the prime modality for the prevention of numerous non-communicable diseases and has also been advocated for resilience against COVID-19 and other infectious diseases. However, there is currently no systematic and quantitative evidence synthesis of the association between physical activity and the strength of the immune system.

Objective

To examine the association between habitual physical activity and (1) the risk of community-acquired infectious disease, (2) laboratory‐assessed immune parameters, and (3) immune response to vaccination.

Methods

We conducted a systemic review and meta-analysis according to PRISMA guidelines. We searched seven databases (MEDLINE, Embase, Cochrane CENTRAL, Web of Science, CINAHL, PsycINFO, and SportDiscus) up to April 2020 for randomised controlled trials and prospective observational studies were included if they compared groups of adults with different levels of physical activity and reported immune system cell count, the concentration of antibody, risk of clinically diagnosed infections, risk of hospitalisation and mortality due to infectious disease. Studies involving elite athletes were excluded. The quality of the selected studies was critically examined following the Cochrane guidelines using ROB2 and ROBINS_E. Data were pooled using an inverse variance random-effects model.

Results

Higher level of habitual physical activity is associated with a 31% risk reduction (hazard ratio 0.69, 95% CI 0.61–0.78, 6 studies, N = 557,487 individuals) of community-acquired infectious disease and 37% risk reduction (hazard ratio 0.64, 95% CI 0.59–0.70, 4 studies, N = 422,813 individuals) of infectious disease mortality. Physical activity interventions resulted in increased CD4 cell counts (32 cells/µL, 95% CI 7–56 cells/µL, 24 studies, N = 1112 individuals) and salivary immunoglobulin IgA concentration (standardised mean difference 0.756, 95% CI 0.146–1.365, 7 studies, N = 435 individuals) and decreased neutrophil counts (704 cells/µL, 95% CI 68–1340, 6 studies, N = 704 individuals) compared to controls. Antibody concentration after vaccination is higher with an adjunct physical activity programme (standardised mean difference 0.142, 95% CI 0.021–0.262, 6 studies, N = 497 individuals).

Conclusion

Regular, moderate to vigorous physical activity is associated with reduced risk of community-acquired infectious diseases and infectious disease mortality, enhances the first line of defence of the immune system, and increases the potency of vaccination.

Protocol registration

The original protocol was prospectively registered with PROSPERO (CRD42020178825).
Erosion-Corrosion Mechanisms of Engineering Steels in Different NaCl Concentrations
Authors: Brownlie F. , Hodgkiess T. , Pearson A. , Galloway A. M.
Published: April 2021

This study utilises a recently developed, enhanced approach to assess detailed aspects of the corrosive wear behaviour of different steel grades in aqueous slurries containing three NaCl concentrations (0.05%NaCl, 3.5%NaCl and 10%NaCl). Erosion-corrosion testing was conducted using a slurry impingement test rig and damage was quantified using volume loss, potentiodynamic polarisation scans and surface topography. Single- and segmented specimens were adopted to yield the contribution of the degradation mechanisms in the two hydrodynamic zones (directly impinged and surrounding area). The overall material losses from the two zones of the stainless steels were observed to increase with increasing salinity. However, the overall material loss for the low-alloy steel was found to increase from 0.05%NaCl to 3.5%NaCl, before reducing when the salinity was further increased to 10%NaCl. Changes in salinity were observed to have the most effect on the corrosion-enhanced mechanical damage mechanism. The in-house developed technique demonstrated good linkage between single samples and the outer area damage region. However, it also showed that the use of single samples can be less successful when assessing highly turbulent (directly impinged) damage regions.
Optimal coordination and service level of the supply chain in the sharing economy: the perspective of social responsibility
Authors: Guo Jie , Guo Yanli
Published: April 2021

The sharing economy has changed people’s lives. These changes have accelerated the pace of life and improved the quality of life, but have also had some negative effects. For example, in China, in the supply chain of the takeout delivery platform, the service deliverer often violates traffic rules to shorten the delivery time. This phenomenon has aroused widespread concern in society. From the perspective of sustainable operation of platform enterprises and reducing social risks, this issue is worthy of in-depth study. First, this study analyses the optimal decision-making about pricing and service efforts, then discusses the supply chain coordination mechanism under a revenue-sharing contract, and finds that the platform’s service level is related to the efforts of deliverers and the elasticity of demand/service. However, under a traditional revenue-sharing contract, the economic returns are not enough to motivate deliverers to avoid violations of traffic regulations; When the increase of cost caused by the improvement of service level is not fully covered by the revenue sharing from the platform, they have a strong incentive to break the rules even if the optimal coordination can be achieved in the supply chain. Second, this study reconstructs the revenue-sharing contract by adding social responsibility to the objective function of the platform enterprises and designs contingent rewards to regulate behaviours of service deliverers. The results indicate that when the contingent reward factor reaches a certain level, the optimal effort of the service deliverers is constrained within a reasonable range, which can to some extent reduce the occurrence of illegal behaviour. Our findings offer fresh insights on coordination of supply chain in the sharing economy, identify new direction for future research on CSR, and provide managers of platform enterprises with suggestions for regulating the behaviour of partners and balance the economic and social benefits.
A deep learning-based computer-aided diagnosis method of X-ray images for bone age assessment
Authors: Li Shaowei , Liu Bowen , Li Shulian , Zhu Xinyu , Yan Yang , Zhang Dongxu
Published: April 2021

Bone age assessment using hand-wrist X-ray images is fundamental when diagnosing growth disorders of a child or providing a more patient-specific treatment. However, as clinical procedures are a subjective assessment, the accuracy depends highly on the doctor’s experience. Motivated by this, a deep learning-based computer-aided diagnosis method was proposed for performing bone age assessment. Inspired by clinical approaches and aimed to reduce expensive manual annotations, informative regions localization based on a complete unsupervised learning method was firstly performed and an image-processing pipeline was proposed. Subsequently, an image model with pre-trained weights as a backbone was utilized to enhance the reliability of prediction. The prediction head was implemented by a Multiple Layer Perceptron with one hidden layer. In compliance with clinical studies, gender information was an additional input to the prediction head by embedded into the feature vector calculated from the backbone model. After the experimental comparison study, the best results showed a mean absolute error of 6.2 months on the public RSNA dataset and 5.1 months on the additional dataset using MobileNetV3 as the backbone.
Design of a consensus-based geriatric assessment tailored for older chronic kidney disease patients: results of a pragmatic approach
Authors: Voorend Carlijn G. N. , Joosten Hanneke , Berkhout-Byrne Noeleen C. , Diepenbroek Adry , Franssen Casper F. M. , Bos Willem Jan W. , Van Buren Marjolijn , Mooijaart Simon P. ,   the POLDER investigators, van Alphen Arjan , Berkhout-Byrne Noeleen , van Breda Fenna , van Buren Marjolijn , Boom Henk , Bos Willem Jan , Diepenbroek Adry , Emmelot-Vonk Marielle , Franssen Casper , Gaillard Carlo A. J. M. , Groeneweg Nel , Hoekstra Bettie , Hommes Nienke , Hoornaar Francoise , Joosten Hanneke , Lagró Joep , Litjens Elisabeth , Molenaar Femke , Mooijaart Simon P. , Neradova Aegida , Peters Mike , Veldman Wilma , Voorend Carlijn , Westerbos Lidwien , Westerman - van der Wijden Carlijne , Wierdsma Judith , Hemmelder M. , Homan van der Heide J. J. , Prantl K. , Rabelink A. J. , de Rooij S. , Stehouwer C.
Published: April 2021

Purpose

Unidentified cognitive decline and other geriatric impairments are prevalent in older patients with advanced chronic kidney disease (CKD). Despite guideline recommendation of geriatric evaluation, routine geriatric assessment is not common in these patients. While high burden of vascular disease and existing pre-dialysis care pathways mandate a tailored geriatric assessment, no consensus exists on which instruments are most suitable in this population to identify geriatric impairments. Therefore, the aim of this study was to propose a geriatric assessment, based on multidisciplinary consensus, to routinely identify major geriatric impairments in older people with advanced CKD.

Methods

A pragmatic approach was chosen, which included focus groups, literature review, inventory of current practices, an expert consensus meeting, and pilot testing. In preparation of the consensus meeting, we composed a project team and an expert panel (n = 33), drafted selection criteria for the selection of instruments, and assessed potential instruments for the geriatric assessment.

Results

Selection criteria related to general geriatric domains, clinical relevance, feasibility, and duration of the assessment. The consensus-assessment contains instruments in functional, cognitive, psychological, somatic, patient preferences, nutritional status, and social domains. Administration of (seven) patient questionnaires and (ten) professional-administered instruments, by nurse (practitioners), takes estimated 20 and 40 min, respectively. Results are discussed in a multidisciplinary meeting including at least nephrology and geriatric expertise, informing nephrology treatment decisions, and follow-up interventions among which comprehensive geriatric assessment.

Conclusion

This first multidisciplinary consensus on nephrology-tailored geriatric assessment intent to benefit clinical care and enhance research comparability for older patients with advanced CKD.
Houngue Éric Noudehouenou v. Republic of Benin
Authors: Akinkugbe Olabisi D.
Published: April 2021

The judgment in Houngue Éric Noudehouenou v. Republic of Benin adds to the growing body of human rights jurisprudence on national electoral processes in Africa's international courts. Houngue Noudehouenou's (Houngue) case was sparked by a series of amendments to the 1990 Constitution of the Republic of Benin (Benin), Law No. 2019-40 (Revised Constitution), and changes to Benin's electoral law (para. 1). Houngue argued that the cumulative effect of the amendments violated his right to stand for election in the upcoming 2021 presidential election as an independent candidate, as well as his right to freedom of expression and freedom of association.
Makuchyan and Minasyan v. Azerbaijan and Hungary
Authors: Milanović Marko , Papić Tatjana
Published: April 2021

The judgment of the European Court of Human Rights (ECtHR or Court) in Makuchyan and Minasyan v. Azerbaijan and Hungary is remarkable both on account of its facts and the peculiar legal issues it raised. In 2004, an ax-wielding Azerbaijani army officer (R.S.) beheaded one Armenian officer, and attempted to kill another, while attending a NATO-organized English language course in Budapest, Hungary. R.S. was prosecuted in Hungary and given a life sentence. Eight years later, R.S. was transferred to Azerbaijan to serve the remainder of his sentence. However, upon his arrival, R.S. received a hero's welcome. He was released, pardoned, promoted, and awarded salary arrears for the period spent in prison, as well as the use of a state apartment in the capital. Many high-ranking Azerbaijani officials expressed their approval of R.S.'s conduct and pardon. (The long-standing Nagorno-Karabakh conflict between Armenia and Azerbaijan of course looms in the background of this story.)
Design thinking and computational thinking: a dual process model for addressing design problems
Authors: Kelly Nick , Gero John S.
Published: April 2021

This paper proposes a relationship between design thinking and computational thinking. It describes design thinking and computational thinking as two prominent ways of understanding how people address design problems. It suggests that, currently, each of design thinking and computational thinking is defined and theorized in isolation from the other. A two-dimensional ontological space of the ways that people think in addressing problems is proposed, based on the orientation of the thinker towards problem and solution generality/specificity. Placement of design thinking and computational thinking within this space and discussion of their relationship leads to the suggestion of a dual process model for addressing design problems. It suggests that, in this model, design thinking and computational thinking are processes that are ontological mirror images of each other, and are the two processes by which thinkers address problems. Thinkers can move fluently between the two. The paper makes a contribution towards the theoretical foundations of design thinking and proposes questions about how design thinking and computational thinking might be both investigated and taught as constituent parts of a dual process.
Earned Citizenship
Authors: Joppke Christian
Published: April 2021

This paper argues that conceptualizing Western state citizenship from the vantage point of advancing liberalism is insufficient. Instead, recently restrictive trends may be summarized under the umbrella of earned citizenship. Conceived of as privilege not right, this is a citizenship that is simultaneously more difficult to get and easier to lose, and it inheres elements of neoliberalism and of nationalism in tandem. One could even call it an instance of neoliberal nationalism, which is neither ethnic nor civic but including on the basis of merit and desert. The rise of earned citizenship is a convergent trend across Western Europe and the classic immigrant nations of North America and Australia.
Honor Among Thieves: Understanding Rhetorical and Material Cooperation Among Violent Nonstate Actors
Authors: Blair Christopher W. , Chenoweth Erica , Horowitz Michael C. , Perkoski Evan , Potter Philip B.K.
Published: April 2021

Cooperation among militant organizations contributes to capability but also presents security risks. This is particularly the case when organizations face substantial repression from the state. As a consequence, for cooperation to emerge and persist when it is most valuable, militant groups must have means of committing to cooperation even when the incentives to defect are high. We posit that shared ideology plays this role by providing community monitoring, authority structures, trust, and transnational networks. We test this theory using new, expansive, time-series data on relationships between militant organizations from 1950 to 2016, which we introduce here. We find that when groups share an ideology, and especially a religion, they are more likely to sustain material cooperation in the face of state repression. These findings contextualize and expand upon research demonstrating that connections between violent nonstate actors strongly shape their tactical and strategic behavior.
Do External Threats Unite or Divide? Security Crises, Rivalries, and Polarization in American Foreign Policy
Authors: Myrick Rachel
Published: April 2021

A common explanation for the increasing polarization in contemporary American foreign policy is the absence of external threat. I identify two mechanisms through which threats could reduce polarization: by revealing information about an adversary that elicits a bipartisan response from policymakers (information mechanism) and by heightening the salience of national relative to partisan identity (identity mechanism). To evaluate the information mechanism, study 1 uses computational text analysis of congressional speeches to explore whether security threats reduce partisanship in attitudes toward foreign adversaries. To evaluate the identity mechanism, study 2 uses public opinion polls to assess whether threats reduce affective polarization among the public. Study 3 tests both mechanisms in a survey experiment that heightens a security threat from China. I find that the external threat hypothesis has limited ability to explain either polarization in US foreign policy or affective polarization among the American public. Instead, responses to external threats reflect the domestic political environment in which they are introduced. The findings cast doubt on predictions that new foreign threats will inherently create partisan unity.
Avian schistosome species in Danish freshwater lakes: relation to biotic and abiotic factors
Authors: Al-Jubury A. , Duan Y. , Kania P.W. , Tracz E.S. , Bygum A. , Jørgensen L.v.G. , Horák P. , Buchmann K.
Published: April 2021

Due to the increased prevalence of human infections with bird schistosome larvae (cercarial dermatitis) associated with bathing in Danish lakes, a nationwide survey of infected intermediate host snails was conducted in 2018–2020. Pulmonate snails (10,225 specimens) were collected from 39 freshwater lakes (in the four major geographic regions in Denmark) and subjected to shedding. Released schistosome cercariae were isolated and identified by polymerase chain reaction and sequencing whereby Trichobilharzia regenti, Trichobilharzia franki, Trichobilharzia szidati and Trichobilharzia anseri were recorded. Infections were primarily determined by biotic factors such as the presence of final host birds and intermediate host snails and water temperature was noted as an important abiotic parameter associated with the infection. No clear connection with other abiotic factors (conductivity, alkalinity, pH, nitrogen, phosphorous) was seen. The widespread occurrence of infected snails, when compared to previous investigations, suggests that climate changes at northern latitudes could be responsible for the increased risk of contracting cercarial dermatitis.
Mitochondrial genome of Rhabdosynochus viridisi (Monogenea: Diplectanidae), a parasite of Pacific white snook Centropomus viridis
Authors: Caña-Bozada V. , Llera-Herrera R. , Fajer-Ávila E.J. , Morales-Serna F.N.
Published: April 2021

We report the nearly complete mitochondrial genome of Rhabdosynochus viridisi – the first for this genus – achieved by combining shotgun sequencing of genomic and cDNA libraries prepared using low-input protocols. This integration of genomic information leads us to correct the annotation of the gene features. The mitochondrial genome consists of 13,863 bp. Annotation resulted in the identification of 12 protein-encoding genes, 22 tRNA genes and two rRNA genes. Three non-coding regions, delimited by three tRNAs, were found between the genes nad5 and cox3. A phylogenetic analysis grouped R. viridisi with three other species of diplectanid monogeneans for which mitochondrial genomes are available.
Refuting the myth of a ‘tsunami’ of mental ill-health in populations affected by COVID-19: evidence that response to the pandemic is heterogeneous, not homogeneous
Authors: Shevlin Mark , Butter Sarah , McBride Orla , Murphy Jamie , Gibson-Miller Jilly , Hartman Todd K. , Levita Liat , Mason Liam , Martinez Anton P. , McKay Ryan , Stocks Thomas V. A. , Bennett Kate , Hyland Philip , Bentall Richard P.
Published: April 2021

Background

The current study argues that population prevalence estimates for mental health disorders, or changes in mean scores over time, may not adequately reflect the heterogeneity in mental health response to the COVID-19 pandemic within the population.

Methods

The COVID-19 Psychological Research Consortium (C19PRC) Study is a longitudinal, nationally representative, online survey of UK adults. The current study analysed data from its first three waves of data collection: Wave 1 (March 2020, N = 2025), Wave 2 (April 2020, N = 1406) and Wave 3 (July 2020, N = 1166). Anxiety-depression was measured using the Patient Health Questionnaire Anxiety and Depression Scale (a composite measure of the PHQ-9 and GAD-7) and COVID-19-related posttraumatic stress disorder (PTSD) with the International Trauma Questionnaire. Changes in mental health outcomes were modelled across the three waves. Latent class growth analysis was used to identify subgroups of individuals with different trajectories of change in anxiety-depression and COVID-19 PTSD. Latent class membership was regressed on baseline characteristics.

Results

Overall prevalence of anxiety-depression remained stable, while COVID-19 PTSD reduced between Waves 2 and 3. Heterogeneity in mental health response was found, and hypothesised classes reflecting (i) stability, (ii) improvement and (iii) deterioration in mental health were identified. Psychological factors were most likely to differentiate the improving, deteriorating and high-stable classes from the low-stable mental health trajectories.

Conclusions

A low-stable profile characterised by little-to-no psychological distress (‘resilient’ class) was the most common trajectory for both anxiety-depression and COVID-19 PTSD. Monitoring these trajectories is necessary moving forward, in particular for the ~30% of individuals with increasing anxiety-depression levels.
Educational Inequalities in Labor Market Exit of Older Workers in 15 European Countries
Authors: MÄCKEN JANA , PRÄG PATRICK , HESS MORITZ , ELLWARDT LEA
Published: April 2021

This article examines country differences in the association between education and voluntary or involuntary labor market exit and whether these country differences map onto institutional characteristics of the countries. Work exit is defined as involuntary or voluntary based on the reasons of exit. Four different types of institutional factors, push and pull, aiming for an earlier work exit and need and maintain factors to retain older workers in employment are considered. Using data from 15 European countries from the longitudinal Survey of Health, Aging and Retirement in Europe (SHARE), discrete-time event history models with a categorical outcome are estimated for each country separately. In a second step, we add macro-level indicators and conduct meta-analyses to analyze country differences. Results show that in almost all countries a social gradient in involuntary work exit exists but not in voluntary exit. Lower-educated workers are more likely to involuntarily exit the labor market. Institutional factors, especially those supporting older workers’ retention in employment, are associated with a smaller social gradient in work exit. Our findings suggest that investments in active labor market expenditures, especially in lifelong learning and rehabilitation for lower educated workers, may help to reduce the social gradient in involuntary work exit.
An efficient LiDAR-based localization method for self-driving cars in dynamic environments
Authors: Zhang Yihuan , Wang Liang , Jiang Xuhui , Zeng Yong , Dai Yifan
Published: April 2021

Real-time localization is an important mission for self-driving cars and it is difficult to achieve precise pose information in dynamic environments. In this paper, a novel localization method is proposed to estimate the pose of self-driving cars using a 3D-LiDAR sensor. First, the multi-frame curb features and laser intensity features are extracted. Meanwhile, based on the high-precision curb map generated offline, obstacles on road are detected using region segmentation methods and their features are removed. Furthermore, a map-matching method is proposed to match the features to the map, a robust iterative closest point algorithm is utilized to deal with curb features along with a probability search method dealing with intensity features. Finally, two separate Kalman filters are used to fuse the low-cost global positioning systems and map-matching results. Both offline and online experiments are carried out in dynamic environments and the results demonstrate the accuracy and robustness of the proposed method.
Conscientious objection in firms
Authors: Blanc Sandrine
Published: April 2021

This article asks whether firms should exempt employees when they object to elements of their work that go against their conscience. Fairness requires that we follow the rules of an organization we have joined voluntarily only if these rules express mutual advantage. In corporations, I argue that subordination and exemption provides for mutual advantage better than subordination plus right of exit. This is because agents want to protect their conscientious convictions, even in hierarchical organizations geared towards efficient preference satisfaction. Thus exemptions should be granted in unforeseeable circumstances, provided the costs are limited.
A systematic review of the evidence supporting post-operative medication use in congenital heart disease
Authors: Thompson Elizabeth J. , Foote Henry P. , King Caitlin E. , Srinivasan Sabarish , Ciociola Elizabeth C. , Leung Dennis , Rotta Alexandre T. , Hill Kevin D. , Cohen-Wolkowiez Michael , Hornik Christoph P.
Published: April 2021

Background:

Targeted drug development efforts in patients with CHD are needed to standardise care, improve outcomes, and limit adverse events in the post-operative period. To identify major gaps in knowledge that can be addressed by drug development efforts and provide a rationale for current clinical practice, this review evaluates the evidence behind the most common medication classes used in the post-operative care of children with CHD undergoing cardiac surgery with cardiopulmonary bypass.

Methods:

We systematically searched PubMed and EMBASE from 2000 to 2019 using a controlled vocabulary and keywords related to diuretics, vasoactives, sedatives, analgesics, pulmonary vasodilators, coagulation system medications, antiarrhythmics, steroids, and other endocrine drugs. We included studies of drugs given post-operatively to children with CHD undergoing repair or palliation with cardiopulmonary bypass.

Results:

We identified a total of 127 studies with 51,573 total children across medication classes. Most studies were retrospective cohorts at single centres. There is significant age- and disease-related variability in drug disposition, efficacy, and safety.

Conclusion:

In this study, we discovered major gaps in knowledge for each medication class and identified areas for future research. Advances in data collection through electronic health records, novel trial methods, and collaboration can aid drug development efforts in standardising care, improving outcomes, and limiting adverse events in the post-operative period.
Independent origins of populations from Dehong State, Yunnan Province, and the multiple introductions and post-introduction admixture sources of mile-a-minute (Mikania micrantha) in China
Authors: Ji Mei , Ze Sangzi , Tang Saichun , Hu Lianrong , Li Junmin
Published: April 2021

Mile-a-minute (Mikania micrantha Kunth) is a tropical American species and has become a worldwide invasive weed. It was first introduced to mainland China in 1983 in Yingjiang City, Dehong State, Yunnan Province. To assess the origins of populations from Dehong State, Yunnan Province, the genetic structure of 427 individuals from 11 M. micrantha populations from Yunnan, Guangxi, Hainan, and Guangdong provinces were analyzed. A total of 28 alleles were detected in 12 nuclear microsatellite loci. Genetic diversity at the population level was relatively high. An analysis of molecular variance showed that most of the variation occurred within populations (82.73%), and only 18.27% occurred among populations. The genetic differentiation coefficient (FST) was 0.183. The estimated gene flow (Nm) from FST was 1.116. The independent origins of four populations collected from Dehong State, Yunnan Province, was determined by the unweighted pair-group method with arithmetic means clustering and STRUCTURE analysis. Three gene clusters and one admixture gene cluster were found. A Mantel test of pairwise Nei’s genetic distances and pairwise geographic distances revealed no evidence for isolation by distance (r = 0.068, P = 0.343). These results suggest that the post-introduction admixture caused by multiple introductions and high gene flow might contribute to the evolutionary adaptation of M. micrantha. These results could provide a scientific basis for the management of invasive M. micrantha.
ICESat‐2 Constraint Analysis and Monitoring System (CAMS)
Authors: Rebold T. W. , Luthcke S. B. , Pennington T. A. , Syed A. , Beall J. L. , Sabaka T. J.
Published: April 2021

The Ice, Cloud and land Elevation Satellite‐2 was launched on 15 September 2018 with mission goals of collecting surface elevation data that can precisely measure ice sheet topography, cloud and aerosol heights, land topography, as well as vegetation height for ecosystems studies. The Constraint Analysis and Monitoring System (CAMS) was implemented as an ICESat‐2 ground system element to perform Mission Planning and Spacecraft Safety Monitoring. Mission Planning requires CAMS to serve as an interface between the Project Science Office, the Instrument Support Facility and the Mission Operation Control Center. By ingesting inputs received from all three groups, the CAMS builds an optimized and deconflicted timeline of science and instrument activities. Based upon the timeline of activities, the CAMS utilizes a sophisticated set of algorithms to model and predict the location and pointing of the spacecraft instrument relative to the Earth and Sun. From the predicted position and pointing, the CAMS provides precise monitoring of instrument health, and performs space asset laser conjunction detection. Furthermore, the CAMS determines alternative plans to prevent detected health constraint violations or mitigate potential laser conjunctions. This paper provides an overview of the CAMS and presents the operational performance of planning science and instrument activities, the monitoring of instrument constraints for health and safety, and the space asset laser conjunction screening and mitigation process.
ICESat‐2 Early Mission Synopsis and Observatory Performance
Authors: Magruder Lori , Neumann Thomas , Kurtz Nathan
Published: April 2021

The Advanced Topographic Laser Altimetry System (ATLAS) onboard the NASA Ice, Cloud, and land Elevation Satellite‐2 (ICESat‐2) is the newest Earth observing satellite for global elevation studies. The primary objectives for ICESat‐2 follow the objectives of its predecessor, ICESat and also focus on providing cryospheric measurements to determine ice sheet mass balance, and monitor both sea ice thickness and extent. However, the global observations support secondary science objectives as well such as biomass estimation, inland water elevation, sea state height and aerosol concentrations. Since launch of ICESat‐2, ATLAS has collected more than a trillion measurements. This study provides a mission overview, a description of the operational components that enable the altimeter products for science, on‐orbit observatory performance, and assessment of the spacecraft attitude control systems that enable repeat measurements to within 10 m and pointing control within ±45 m. These metrics should be considered for ground‐based validation campaigns or science investigations.
Sensitivity of Tropical Extreme Precipitation to Surface Warming in Aquaplanet Experiments Using a Global Nonhydrostatic Model
Authors: Uribe Alejandro , Vial Jessica , Mauritsen Thorsten
Published: April 2021

Increases of atmospheric water vapor holding capacity with temperature (7% K−1–8% K−1, CC‐rate) can lead to increasing extreme precipitation (EP). Observations show that tropical EP has increased during the last five decades with a rate higher than in the extratropics. Global climate models (GCM's) diverge in the magnitude of increase in the tropics, and cloud‐resolving models (CRM's) indicate correlations between changes in tropical EP and organization of deep convection. We conducted global‐scale aquaplanet experiments at a wide range of resolutions with explicit and parameterized convection to bridge the gap between GCM's and CRM's. We found increases of tropical EP beyond the CC rate, with similar magnitudes when using explicit convection and parametrized convection at the resolution it is tuned for. Those super‐CC rates are produced due to strengthening updrafts where extreme precipitation occurs, and they do not exhibit relations with changes in convective organization.
Multidecadal Evolution of the Turbidity Maximum Zone in a Macrotidal River Under Climate and Anthropogenic Pressures
Authors: Jalón‐Rojas I. , Dijkstra Y. M. , Schuttelaars H. M. , Brouwer R. L. , Schmidt S. , Sottolichio A.
Published: April 2021

Climate and human pressures can influence the evolution of estuarine sediment dynamics concurrently, but the understanding and quantification of their cause–effect relationships are still challenging due to the occurrence of complex hydro‐morpho‐sedimentary feedbacks. The Garonne Tidal River (GTR, upper Gironde Estuary, France) is a clear example of a system stressed by both anthropogenic and climate change, as it has been subject to decreasing river discharges, natural morphological changes, and gravel extraction. To understand the relative effect of each hydrological and geomorphological pressure on the turbidity maximum zone (TMZ), the sediment dynamics in the GTR over the last six decades was evaluated using the width‐averaged idealized iFlow model. Model results show a gradual increase in tidal amplitude and currents over the decades that has led to the upstream shift of the landward sediment‐transport capacity components (external M4 tide, spatial settling lag, and tidal return flow). The upstream displacement of the TMZ between the 1950s and the 2010s was estimated to be at least 19 km, of which about three fourth was induced by geomorphological changes and one fourth by hydrological changes. Concerning the geomorphological changes, the natural evolution of the lower Gironde morphology was the main pressure inducing the displacement of the TMZ in the GTR. Anthropogenic and natural changes in morphology and bed roughness in the GTR itself also contributed to this evolution. The natural geomorphological changes were, in turn, probably promoted by the evolution of sediment dynamics, so this study reveals the closed circle that governs the intensification of the TMZ.
Simulations of the Surf Zone Eddy Field and Cross‐Shore Exchange on a Nonidealized Bathymetry
Authors: O'Dea Annika , Kumar Nirnimesh , Haller Merrick C.
Published: April 2021

X‐band radar observations from the 2017 Inner Shelf Dynamics Experiment (ISDE) in central California show multiple persistent and pulsatory rip currents on a relatively straight coastline with alongshore‐varying bathymetry. Although past studies have assessed the characteristics of transient rip currents on alongshore uniform beaches, the relative balance of transient versus steady rip current behavior on nonuniform beaches in realistic wave conditions remains poorly understood. Here, a phase‐resolving Boussinesq‐type wave model (funwaveC) is used to assess the role of alongshore‐varying bathymetry and incident conditions in controlling mean and transient surf zone vorticity and velocity fields and their effect on surf zone exchange. The model simulates wave conditions chosen from the ISDE observations and utilizes both an alongshore‐varying bathymetry estimated from the ISDE radar observations and a uniform bathymetry. Results show that the variable bathymetry significantly increases the alongshore‐ and time‐averaged kinetic energy but that this increase is primarily due to the increase in the standing component resulting from mean circulation patterns, with only small changes in the transient component. A variable bathymetry also increases the spectral energy of surf zone vorticity and time‐averaged vorticity forcing at large spatial scales (>100 m). Wave directional spreading has a large impact on the alongshore‐ and time‐averaged enstrophy and on the spectral energy of surf zone vorticity and vorticity forcing at smaller spatial scales (<100 m). In the presence of a directionally spread wavefield, an alongshore‐varying bathymetry slightly increases the total exchange velocity but has little effect on its transient component.
Christiansen Feature Map From the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment: Improved Corrections and Derived Mineralogy
Authors: Lucey Paul G. , Greenhagen Benjamin , Donaldson Hanna Kerri , Bowles Neil , Flom Abigail , Paige David A.
Published: April 2021

Maps of plagioclase, olivine, and pyroxene at 1 km resolution are derived from a combination of data from the Diviner Lunar Radiometer on the Lunar Reconnaissance Orbiter and the Kaguya Multiband Imager. The Diviner instrument features three infrared bands designed to characterize a spectral feature of lunar soils that is sensitive to the average silica polymerization of the surface called the Christiansen Feature, which is directly sensitive to the presence of plagioclase, the dominant lunar silicate. Existing global mineral maps based on near‐IR data largely infer the presence of plagioclase from the bright mineral’s effect on total reflectance, excepting in rare locations where the surface is nearly pure plagioclase and a weak feature in the plagioclase near‐IR spectrum can be relied upon. By integrating both wavelength regions we produced more robust estimates of the abundance of the three dominant minerals. In the process of this work, we also improved the removal of space weathering effects from Christiansen Feature maps, and showed that silica rich compositional anomalies could be reliably detected by decorrelating Christiansen Feature and FeO maps. New silica‐rich locations are reported as are the global abundances of the three major silicates.
Elastic Properties of the Pyrite‐Type FeOOH‐AlOOH System From First‐Principles Calculations
Authors: Thompson Elizabeth C. , Campbell Andrew J. , Tsuchiya Jun
Published: April 2021

The stability, structure, and elastic properties of pyrite‐type (FeS2 structured) FeO2H were determined using density functional theory‐based computations with an internally consistent Coulombic self‐interaction term (Ueff). The properties of pyrite‐type FeO2H are compared to that of pyrite‐type AlO2H, with which it likely forms a solid solution at high temperature, as well as the respective lower pressure CaCl2‐type polymorphs of both endmembers: ϵ‐FeOOH and δ‐AlOOH. Due to substantial differences in the CaCl2‐type → pyrite‐type structural transition pressures of these endmembers, the stabilities of the (Al,Fe)O2H solid solution polymorphs are anticipated to be compositionally driven at lower mantle pressures. As the geophysical properties of (Al,Fe)OOH are structurally dependant, interpretations regarding the contribution of pyrite‐type FeO2H to seismically observed features must take into account the importance of this broad phase loop. With this in mind, Fe‐rich pyrite‐type (Al,Fe)OOH may coexist with Al‐dominant CaCl2‐type δ‐(Al,Fe)OOH in the deep Earth. Furthermore, pyrite‐type (Al0.5–0.6,Fe0.4–0.5)O2H can reproduce the reduced compressional and shear velocities characteristic of seismically observed ultra low velocity zones in the Earth's lowermost mantle while Al‐dominant but Fe‐bearing CaCl2‐type δ‐(Al,Fe)OOH may contribute to large low shear velocity provinces.
Multiplexed targeting of miRNA-210 in stem cell-derived extracellular vesicles promotes selective regeneration in ischemic hearts
Authors: Song Byeong-Wook , Lee Chang Youn , Kim Ran , Kim Won Jung , Lee Hee Won , Lee Min Young , Kim Jongmin , Jeong Jee-Yeong , Chang Woochul
Published: April 2021

Extracellular vesicles (EVs) are cell derivatives containing diverse cellular molecules, have various physiological properties and are also present in stem cells used for regenerative therapy. We selected a “multiplexed target” that demonstrates multiple effects on various cardiovascular cells, while functioning as a cargo of EVs. We screened various microRNAs (miRs) and identified miR-210 as a candidate target for survival and angiogenic function. We confirmed the cellular and biological functions of EV-210 (EVs derived from ASCmiR-210) secreted from adipose-derived stem cells (ASCs) transfected with miR-210 (ASCmiR-210). Under hypoxic conditions, we observed that ASCmiR-210 inhibits apoptosis by modulating protein tyrosine phosphatase 1B (PTP1B) and death-associated protein kinase 1 (DAPK1). In hypoxic endothelial cells, EV-210 exerted its angiogenic capacity by inhibiting Ephrin A (EFNA3). Furthermore, EV-210 enhanced cell survival under the control of PTP1B and induced antiapoptotic effects in hypoxic H9c2 cells. In cardiac fibroblasts, the fibrotic ratio was reduced after exposure to EV-210, but EVs derived from ASCmiR-210 did not communicate with fibroblasts. Finally, we observed the functional restoration of the ischemia/reperfusion-injured heart by maintaining the intercommunication of EVs and cardiovascular cells derived from ASCmiR-210. These results suggest that the multiplexed target with ASCmiR-210 is a useful tool for cardiovascular regeneration.
The interplay of microRNAs and transcription factors in autophagy regulation in nonalcoholic fatty liver disease
Authors: Kim Yumi , Lee Da-Hye , Park So-Hyun , Jeon Tae-Il , Jung Chang Hwa
Published: April 2021

The autophagy-lysosomal degradation system has an important role in maintaining liver homeostasis by removing unnecessary intracellular components. Impaired autophagy has been linked to nonalcoholic fatty liver disease (NAFLD), which includes hepatitis, steatosis, fibrosis, and cirrhosis. Thus, gaining an understanding of the mechanisms that regulate autophagy and how autophagy contributes to the development and progression of NAFLD has become the focus of recent studies. Autophagy regulation has been thought to be primarily regulated by cytoplasmic processes; however, recent studies have shown that microRNAs (miRNAs) and transcription factors (TFs) also act as key regulators of autophagy by targeting autophagy-related genes. In this review, we summarize the miRNAs and TFs that regulate the autophagy pathway in NAFLD. We further focus on the transcriptional and posttranscriptional regulation of autophagy and discuss the complex regulatory networks involving these regulators in autophagy. Finally, we highlight the potential of targeting miRNAs and TFs involved in the regulation of autophagy for the treatment of NAFLD.
Salt-induced recruitment of specific root-associated bacterial consortium capable of enhancing plant adaptability to salt stress
Authors: Li Hong , La Shikai , Zhang Xu , Gao Lihong , Tian Yongqiang
Published: April 2021

Salinity is a major abiotic stress threatening crop production. Root-derived bacteria (RDB) are hypothesized to play a role in enhancing plant adaptability to various stresses. However, it is still unclear whether and how plants build up specific RDB when challenged by salinity. In this study, we measured the composition and variation in the rhizosphere and endophyte bacteria of salt-sensitive (SSs) and salt-resistant (SRs) plants under soil conditions with/without salinity. The salt-induced RDB (both rhizobiomes and endophytes) were isolated to examine their effects on the physiological responses of SSs and SRs to salinity challenge. Moreover, we examined whether functional redundancy exists among salt-induced RDB in enhancing plant adaptability to salt stress. We observed that although SSs and SRs recruited distinct RDB and relevant functions when challenged by salinity, salt-induced recruitment of specific RDB led to a consistent growth promotion in plants regardless of their salinity tolerance capacities. Plants employed a species-specific strategy to recruit beneficial soil bacteria in the rhizosphere rather than in the endosphere. Furthermore, we demonstrated that the consortium, but not individual members of the salt-induced RDB, provided enduring resistance against salt stress. This study confirms the critical role of salt-induced RDB in enhancing plant adaptability to salt stress.