bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulating the Electronic Structure of Single‐Atom Catalysts on 2D Nanomaterials for Enhanced Electrocatalytic Performance
Authors: Zhu Yuanzhi , Peng Wenchao , Li Yang , Zhang Guoliang , Zhang Fengbao , Fan Xiaobin 
Published: March 2019

AbstractSingle‐atom catalysts (SACs) on 2D nanomaterials have great potential as efficient and low‐cost electrocatalysts for clean energy technologies. The coordination environments, as well as the physicochemical properties of the 2D supports, play key roles in tuning the catalytic activity and reaction mechanism of the single‐atom centers. This review first summarizes the suitable synthetic strategies of single‐atom on different 2D supports. The methods that facilitate the formation of relative homogeneous structure and enable the regulation of the surrounding atomic environment of metal center are discussed. Furthermore, the recent progress of SACs for energy‐related electrochemical applications is reviewed, including oxygen reduction reaction, hydrogen evolution reaction, oxygen evolution reaction, CO2 reduction reaction, and nitrogen reduction reaction. The strategies about modulation of the electronic structure of single‐atom for enhanced performance are highlighted, together with a discussion of the current issues and the prospects of this field.
Hematopoietic Stem Cell Dynamics Are Regulated by Progenitor Demand: Lessons from a Quantitative Modeling Approach
Authors: Klose Markus , Florian Maria Carolina , Gerbaulet Alexander , Geiger Hartmut , Glauche Ingmar 
Published: March 2019

AbstractThe prevailing view on murine hematopoiesis and on hematopoietic stem cells (HSCs) in particular derives from experiments that are related to regeneration after irradiation and HSC transplantation. However, over the past years, different experimental techniques have been developed to investigate hematopoiesis under homeostatic conditions, thereby providing access to proliferation and differentiation rates of hematopoietic stem and progenitor cells in the unperturbed situation. Moreover, it has become clear that hematopoiesis undergoes distinct changes during aging with large effects on HSC abundance, lineage contribution, asymmetry of division, and self-renewal potential. However, it is currently not fully resolved how stem and progenitor cells interact to respond to varying demands and how this balance is altered by an aging-induced shift in HSC polarity. Aiming toward a conceptual understanding, we introduce a novel in silico model to investigate the dynamics of HSC response to varying demand. By introducing an internal feedback within a heterogeneous HSC population, the model is suited to consistently describe both hematopoietic homeostasis and regeneration, including the limited regulation of HSCs in the homeostatic situation. The model further explains the age-dependent increase in phenotypic HSCs as a consequence of the cells' inability to preserve divisional asymmetry. Our model suggests a dynamically regulated population of intrinsically asymmetrically dividing HSCs as suitable control mechanism that adheres with many qualitative and quantitative findings on hematopoietic recovery after stress and aging. The modeling approach thereby illustrates how a mathematical formalism can support both the conceptual and the quantitative understanding of regulatory principles in HSC biology.
Bmi1 Overexpression in Mesenchymal Stem Cells Exerts Antiaging and Antiosteoporosis Effects by Inactivating p16/p19 Signaling and Inhibiting Oxidative Stress
Authors: Chen Guangpei , Zhang Ying , Yu Shuxiang , Sun Wen , Miao Dengshun 
Published: March 2019

Abstract
We previously demonstrated that Bmi1 deficiency leads to osteoporosis phenotype by inhibiting the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs), but it is unclear whether overexpression of Bmi1 in MSCs stimulates skeletal development and rescues Bmi1 deficiency-induced osteoporosis. To answer this question, we constructed transgenic mice (Bmi1Tg) that overexpressed Bmi1 driven by the Prx1 gene and analyzed their skeletal phenotype differences with that of wild-type littermates. We then hybridized Bmi1Tg to Bmi1−/− mice to generate Bmi1−/− mice overexpressing Bmi1 in MSCs and compared their skeletal phenotypes with those of Bmi1−/− and wild-type mice using imaging, histopathological, immunohistochemical, histomorphometric, cellular, and molecular methods. Bmi1Tg mice exhibited enhanced bone growth and osteoblast formation, including the augmentation of bone size, cortical and trabecular volume, number of osteoblasts, alkaline phosphatase (ALP)-positive and type I collagen-positive areas, number of total colony forming unit fibroblasts (CFU-f) and ALP+ CFU-f, and osteogenic gene expression levels. Consistently, MSC overexpressing Bmi1 in the Bmi1−/− background not only largely reversed Bmi1 systemic deficiency-induced skeletal growth retardation and osteoporosis, but also partially reversed Bmi1 deficiency-induced systemic growth retardation and premature aging. To further explore the mechanism of action of MSCs overexpressing Bmi1 in antiosteoporosis and antiaging, we examined changes in oxidative stress and expression levels of p16 and p19. Our results showed that overexpression of Bmi1 in MSCs inhibited oxidative stress and downregulated p16 and p19. Taken together, the results of this study indicate that overexpression of Bmi1 in MSCs exerts antiaging and antiosteoporosis effects by inactivating p16/p19 signaling and inhibiting oxidative stress. Stem Cells 2019;37:1200–1211
Cyclic tensile testing of a three‐way panel connection for precast wall‐slab‐wall structures
Authors: Brunesi Emanuele , Peloso Simone , Pinho Rui , Nascimbene Roberto 
Published: March 2019

Wall‐slab‐wall buildings, in precast configuration or not, are relatively widespread in many European and non‐European countries, independently of the level and nature of seismic hazard to which the country is prone. Thus, this building archetype, featuring no columns or beams, but only slabs and walls, can be equally found both in areas characterized by potentially high‐damaging tectonic earthquakes and regions where small‐to‐medium‐size natural/anthropogenic seismic events would instead be expected.Notwithstanding the above, relatively little information has been offered so far on the seismic response/performance of these structures and their key components, which in case of a precast system/layout will inevitably be the connections between the structural elements. To partly fill such knowledge gap, this paper concerns the latter configuration and deals with experimental testing of panel‐to‐panel joints, which are not only two‐way links but also three‐way connections because it is very common for such structures that contiguous panels are connected to a transverse shear wall.Not surprisingly, very recent pseudostatic and shake‐table tests on full‐scale specimens, undertaken by the authors to characterize the performance of this structural system up to incipient/near collapse, have indicated how the latter panel joints are the weakest link of the system tested, thus prompting further component testing, in cyclic/asymmetric fashion, to single out the response of the joint. Monotonic and cyclic response curves of the five specimens and the counterpart damage patterns revealed that the observed flexural failure mechanism is very stable and aligns very well with that mobilized by the full‐scale building tests.
Effects of Mineralogy, Exchange Capacity, Surface Area and Grain Size on Lithium Sorption to Zeolitic Alluvium near Yucca Mountain, Nevada
Authors: Sullivan Enid J. , Reimus Paul W. , Chipera Steve J. , Counce Dale 
Published: March 2019

AbstractThe Li+ ion is used frequently as an environmentally acceptable surrogate for sorbing radionuclides in field tracer tests, and experiments using Li are an important part of assessing the potential transport of radionuclides in saturated alluvium south of Yucca Mountain, Nevada, the site of a proposed nuclear waste repository. Equilibrium partition constants (Li+ Kds) were measured using batch studies incorporating a wide range of Li+ concentrations and two different grain-size fractions of alluvium samples from multiple depth intervals in two wells. Cation exchange capacity, surface area, bulk mineralogy from quantitative X-ray powder diffraction, and trace Mn- and Fe-oxyhydroxide mineralogy from extractive studies were evaluated as predictors for linearized Li+ Kd values (K1in) in the alluvium. Many of the predictor variables are correlated with each other and this was considered in the analysis. Linearized Kd values were consistently higher for fine particle-size fractions than for coarse fractions. Single and multivariate linear regression analyses indicated that the clinoptilolite + smectite content, taken together as a combined variable, was the best predictor for Li+ sorption in the alluvium, although clinoptilolite content was clearly a better predictor when the two variables were considered separately in simple linear regressions. Even so, Li+ Klin predictions based on clinoptilolite and smectite abundance were accurate only to within about ±100%. This uncertainty suggests that there is either a high inherent variability in Li+ Klin values or that additional alluvium characteristics not measured or evaluated here may play an important role in simple Li+ cation exchange in the alluvium.
Soil carbon stock in olive groves agroforestry systems under different management and soil characteristics
Authors: Bateni Camilla , Ventura Maurizio , Tonon Giustino , Pisanelli Andrea 
Published: March 2019

AbstractThe atmospheric concentrations of greenhouse gases have increased to unprecedented levels during last decades, raising concerns about their effect on climate change. Agriculture and land use change play an important role in atmospheric CO2 emission and fixation, especially by affecting the soil carbon (C) storage. In this context, agroforestry systems (AFSs) could play an important role contributing to climate change mitigation. Given the importance of olive cultivation in the Mediterranean region, it is important to investigate soil C stock in olive groves, and to assess which agronomic practices could improve the soil C stock in these systems. For this reason, a study was conducted in different olive groves, including conventional and organic management, and a typical silvopastoral AFS. Furthermore, an abandoned olive grove and nearby forest were examined as a comparison. Soil samples were collected in each farm and analysed for C content and physico-chemical characteristics. This study indicates that, irrespective of the management, olive groves in the Umbria region of Italy are characterised by a high level of soil C stock if compared to those growing in other areas and to forest ecosystems, indicating that the practices adopted in the area are not negatively affecting soil C storage. A slightly lower soil C stock was measured in the silvopastoral AFS in comparison to the other farms, while high soil C stock was associated with the use of pomace, suggesting that this practice can be used to further increase soil C stock in olive orchards.
TNF-α G-308A genetic variants, serum CRP-hs concentration and DNA damage in obese women
Authors: Włodarczyk Marta , Ciebiera Michał , Nowicka Grażyna 
Published: March 2019

Abstract
Obesity is associated with inflammation, which can disturb genome stability. Tumor necrosis factor (TNF-α) polymorphism was found to affect TNF-α protein production and inflammation. Therefore, the present study illustrates the relationship between TNF-α polymorphism, the degree of inflammation assessed by serum high sensitivity C-reactive protein concentration (CRP-hs) and basal DNA damage in patients with obesity (BMI 30–34.9 kg/m2) and control subjects with proper body mass (BMI < 25 kg/m2). A total of 115 participants (75 obese premenopausal women; and 40 age-, and gender-matched controls) were included. Biochemical parameters (serum concentrations of total-cholesterol, HDL-cholesterol, LDL- cholesterol, triglycerides, glucose, apolipoprotein AI, CRP-hs) and endogenous DNA damage (determined by comet assay) were measured. TNF-α G-308A polymorphism (rs1800629) was analyzed by PCR-RFLP (PCR-restriction fragments length polymorphism). An effect of TNF-α genotype on serum CRP-hs concentration was noted (p = 0.031). In general, carriers of the rare A allele of the TNF-α G-308A polymorphism had significantly lower endogenous DNA damage and serum CRP-hs concentrations than GG homozygotes, however, the protective effect of the A allele was especially visible in non-obese women. Serum CRP-hs concentrations and levels of DNA damage (% DNA in tail) were significantly higher in obese than in controls (p = 0.001 and p < 0.0001, respectively). The adjusted multiple linear regression analyses revealed a significant, independent impact of obesity on DNA damage (p = 0.00000) and no effect of other covariates i.e. age, TNF-α genotype and serum CRP-hs concentration. Our study showed that obesity has a significant impact on the levels of endogenous DNA damage. Obesity abolished the protective effect of A allele of the TNF-α G-308A polymorphism on DNA damage and on inflammation development observed in non-obese A allele carriers.
Proximate Sources of Change in Trajectories of First Marriage in the United States, 1960–2010
Authors: Hendi Arun S. 
Published: March 2019

AbstractThis study examines proximate sources of change in first-marriage trajectories in the United States between 1960 and 2010. This was a period of tremendous social change: divorce became more common, people started marrying later or not marrying at all, innovations in medicine and changes in social and behavioral factors led to reduced mortality, inequality grew stronger and was reflected by more intense assortative mating, and the country underwent a massive educational expansion. Each of these factors influenced the formation and dissolution of first marriages over this period. This article extends the multiple-decrement life table to incorporate heterogeneity and assortative mating, which allows the quantification of how changes in the incidence of marriage, divorce, and mortality, along with changes in educational attainment and assortative mating, have shaped trends in first-marriage trajectories. The model is used to prove that stronger educational assortative mating leads to longer average durations of first marriage. Using data from multiple sources and this model, this study shows that although the incidence of divorce was the primary determinant of changes in first-marriage trajectories between 1960 and 1980, it has played a relatively smaller role in driving change in marital trajectories between 1980 and 2010. Instead, factors such as later age at first marriage, educational expansion, declining mortality, narrowing sex differences in mortality, and more intense educational assortative mating have been the major drivers of changes in first-marriage trajectories since 1980.
Time perspective, sports club membership, and physical self‐concept among adolescents: A person‐centered approach
Authors: Konowalczyk Svenja , Rade F. Clemens A. , Mello Zena R. 
Published: March 2019

AbstractIntroductionTime perspective is defined as thoughts and feelings about the past, present, and future and is theorized to underlie human behavior. Prior research has shown relationships among time perspective and academic achievement, substance use, and risky‐driving. In this study, time perspective was extended to sports club membership and physical self‐concept among adolescents.MethodsTime perspective was assessed with a scale that measures positive and negative feelings about the past, present, and future. Latent time attitude profiles were generated with data that included sports club membership and physical self‐concept. Participants were German (N = 901; 46.2% female), Luxembourgian (N = 661; 46.7% female), and Spanish (N = 789; 49.0% female) adolescents (12–18 years‐old).ResultsLatent profile analyses indicated that across the three samples the same number and type of profiles were observed: Ambivalent, Balanced, Optimistic, Past Negative, and Positive. Time attitude profiles were related to sports club membership and physical self‐concept. Adolescents with positive attitudinal profiles were more engaged in sports clubs and reported a higher physical self‐concept than adolescents in negative attitudinal profiles.ConclusionsTime perspective was conceptualized as time attitudes and operationalized as positive and negative feelings about the past, present, and future. Results showed that five latent time attitudes profiles were observed and that profile membership was associated with sports club membership and physical self‐concept. These associations were demonstrated with three independent samples. Findings were discussed in light of implications for intervention programs that use time perspective to promote physical health among adolescents.
A NOTE ON A-ANNIHILATED GENERATORS OF H*QX
Authors: ZARE HADI 
Published: March 2019

AbstractFor a path connected space X, the homology algebra $H_*(QX; \mathbb{Z}/2)$ is a polynomial algebra over certain generators QIx. We reinterpret a technical observation, of Curtis and Wellington, on the action of the Steenrod algebra A on the Λ algebra in our terms. We then introduce a partial order on each grading of H*QX which allows us to separate terms in a useful way when computing the action of dual Steenrod operations $Sq^i_*$ on $H_*(QX; \mathbb{Z}/2)$. We use these to completely characterise the A-annihilated generators of this polynomial algebra. We then propose a construction for sequences I so that QIx is A-annihilated. As an application, we offer some results on the form of potential spherical classes in H*QX upon some stability condition under homology suspension. Our computations provide new numerical conditions in the context of hit problem.
How does health consciousness influence attitudes of elderly people towards traceable agricultural products? Perspectives of the technology acceptance model
Authors: Lin Hung-Chou , Kuo Su-Hui 
Published: March 2019

AbstractRecently, internet usage among elderly adults has been increasing and becoming more mainstream; with the ageing population in Taiwan, concerns over health are on the rise, and this is directly related to the products that people eat. The main objectives of this study were to develop an integrated extensibility model incorporating the technology acceptance model and to investigate the impact of health consciousness on elderly adults’ acceptance of technology in relation to traceability information websites in Taiwan. This study used structural equation modelling to analyse the data. The results revealed that elderly people with high health consciousness and high perceived usefulness had more positive attitudes towards products than those with low health consciousness and low perceived usefulness, and those with high health consciousness and high perceived ease of use had more positive attitudes than those with low health consciousness and low perceived ease of use in relation to the agricultural product traceability system.
Multi-track pension system and life satisfaction of urban elders in China
Authors: Hu Anning , Wang Yihong 
Published: March 2019

AbstractThere exist three pension systems for urban older residents in China: the pension for government and public institutions (PGPI), the worker's old-age insurance for enterprise employees (WOI) and the urban residents’ social pension insurance (URSPI). This study examines how this multi-track pension system relates to older urbanites’ life satisfaction. The ordered logistic regression model was fitted to analyse the urban sample of the China Longitudinal Ageing Social Survey (60+ years), a nationwide representative survey collected in 2014. The mediation analyses were further adopted to investigate the potential formative mechanisms. A significantly higher level of life satisfaction was detected for those who receive PGPI benefits relative to those who have access to URSPI and WOI, but no significant difference is detected between URSPI and WOI. Further analyses suggest that the advantage of PGPI in terms of life satisfaction is mediated not through monetary resources, but through the dispositional factor of perceived self-value for the society. This study suggests that different institutional configurations of the pension system stratify older urbanites’ subjective wellbeing by virtue of factors that are associated with people's capabilities of acting and functioning.
Estimate of the annual burden of foodborne illness in nondeployed active duty US Army Service Members: five major pathogens, 2010–2015
Authors: Mullaney S. B. , Hyatt D. R. , Salman M. D. , Rao S. , McCluskey B. J. 
Published: March 2019

Abstract
In this study, we estimate the burden of foodborne illness (FBI) caused by five major pathogens among nondeployed US Army service members. The US Army is a unique population that is globally distributed, has its own food procurement system and a food protection system dedicated to the prevention of both unintentional and intentional contamination of food. To our knowledge, the burden of FBI caused by specific pathogens among the US Army population has not been determined. We used data from a 2015 US Army population survey, a 2015 US Army laboratory survey and data from FoodNet to create inputs for two model structures. Model type 1 scaled up case counts of Campylobacter jejuni, Shigella spp., Salmonella enterica non-typhoidal and STEC non-O157 ascertained from the Disease Reporting System internet database from 2010 to 2015. Model type 2 scaled down cases of self-reported acute gastrointestinal illness (AGI) to estimate the annual burden of Norovirus illness. We estimate that these five pathogens caused 45 600 (5%–95% range, 30 300–64 000) annual illnesses among nondeployed active duty US Army Service members. Of these pathogens, Norovirus, Campylobacter jejuni and Salmonella enterica non-typhoidal were responsible for the most illness. There is a tremendous burden of AGI and FBI caused by five major pathogens among US Army Soldiers, which can have a tremendous impact on readiness of the force. The US Army has a robust food protection program in place, but without a specific active FBI surveillance system across the Department of Defence, we will never have the ability to measure the effectiveness of modern, targeted, interventions aimed at the reduction of specific foodborne pathogens.