bluuebunny/crossref_metadata_2025_split huggingface dataset:
DE ZOLT’S POSTULATE: AN ABSTRACT APPROACH
Authors: GIOVANNINI EDUARDO N. , HAEUSLER EDWARD H. , LASSALLE-CASANAVE ABEL , VELOSO PAULO A. S. 
Published: September 2019

AbstractA theory of magnitudes involves criteria for their equivalence, comparison and addition. In this article we examine these aspects from an abstract viewpoint, by focusing on the so-called De Zolt’s postulate in the theory of equivalence of plane polygons (“If a polygon is divided into polygonal parts in any given way, then the union of all but one of these parts is not equivalent to the given polygon”). We formulate an abstract version of this postulate and derive it from some selected principles for magnitudes. We also formulate and derive an abstract version of Euclid’s Common Notion 5 (“The whole is greater than the part”), and analyze its logical relation to the former proposition. These results prove to be relevant for the clarification of some key conceptual aspects of Hilbert’s proof of De Zolt’s postulate, in his classicalFoundations of Geometry(1899). Furthermore, our abstract treatment of this central proposition provides interesting insights for the development of a well-behaved theory ofcompatiblemagnitudes.
Atrazine induces penis abnormalities including hypospadias in mice
Authors: Govers Luke C. , Harper Alesia P. , Finger Bethany J. , Mattiske Deidre M. , Pask Andrew J. , Green Mark P. 
Published: September 2019

AbstractUse of the herbicide atrazine (ATR) is banned in the European Union; yet, it is still widely used in the USA and Australia. ATR is known to alter testosterone and oestrogen production and thus reproductive characteristics in numerous species. In this proof of concept study, we examined the effect of ATR exposure, at a supra-environmental dose (5 mg/kg bw/day), beginning on E9.5 in utero, prior to sexual differentiation of the reproductive tissues, until 26 weeks of age, on the development of the mouse penis. Notably, this is the first study to specifically investigate whether ATR can affect penis characteristics. We show that ATR exposure, beginning in utero, causes a shortening (demasculinisation) of penis structures and increases the incidence of hypospadias in mice. These data indicate the need for further studies of ATR on human reproductive development and fertility, especially considering its continued and widespread use.
Prenatal and childhood exposures are associated with thymulin concentrations in young adolescent children in rural Nepal
Authors: Palmer Amanda C. , Schulze Kerry J. , Khatry Subarna K. , West Keith P. 
Published: September 2019

AbstractThe thymus undergoes a critical period of growth and development early in gestation and, by mid-gestation, immature thymocytes are subject to positive and negative selection. Exposure to undernutrition during these periods may permanently affect phenotype. We measured thymulin concentrations, as a proxy for thymic size and function, in children (n= 290; aged 9–13 years) born to participants in a cluster-randomized trial of maternal vitamin A or β-carotene supplementation in rural Nepal (1994–1997). The geometric mean (95% confidence interval) thymulin concentration was 1.37 ng/ml (1.27, 1.47). A multivariate model of early-life exposures revealed a positive association with gestational age at delivery (β= 0.02;P= 0.05) and higher concentrations among children born to β-carotene-supplemented mothers (β= 0.19;P< 0.05). At ∼9–12 years of age, thymulin was positively associated with all anthropometric measures, with height retained in our multivariate model (β= 0.02;P< 0.001). There was significant seasonal variation: concentrations tended to be lower pre-monsoon (β= −0.13;P= 0.15), during the monsoon (β= −0.22;P= 0.04), and pre-harvest (β= −0.34;P= 0.01), relative to the post-harvest season. All early-life associations, except supplementation, were mediated in part by nutritional status at follow-up. Our findings underscore the known sensitivity of the thymus to nutrition, including potentially lasting effects of early nutritional exposures. The relevance of these findings to later disease risk remains to be explored, particularly given the role of thymulin in the neuroendocrine regulation of inflammation.
Oxygen Ion Dynamics in the Earth's Ring Current: Van Allen Probes Observations
Authors: Yue Chao , Bortnik Jacob , Li Wen , Ma Qianli , Wang Chih‐Ping , Thorne Richard M. , Lyons Larry , Reeves Geoffrey D. , Spence Harlan E. , Gerrard Andrew J. , Gkioulidou Matina , Mitchell Donald G. 
Published: September 2019

AbstractOxygen (O+) enhancements in the inner magnetosphere are often observed during geomagnetically active times, such as geomagnetic storms. In this study, we quantitatively examine the difference in ring current dynamics with and without a substantial O+ ion population based on almost 6 years of Van Allen Probes observations. Our results have not only confirmed previous finding of the role of O+ ions to the ring current but also found that abundant O+ ions are always present during large storms when sym‐H < −60 nT without exception, while having the pressure ratio (ℛ) between O+ and proton (H+) larger than 0.8 and occasionally even larger than 1 when L < 3. Simultaneously, the pressure anisotropy decreases with decreasing sym‐H and increasing L shell. The pressure anisotropy decrease during the storm main phase is likely related to the pitch angle isotropization processes. In addition, we find that ℛ increases during the storm main phase and then decreases during the storm recovery phase, suggesting faster buildup and decay of O+ pressure compared to H+ ions, which are probably associated with some species dependent source and/or energization as well as loss processes in the inner magnetosphere.
Recognition of Mesoscale Strike‐Slip En Echelon Faults From 2‐D Nonporous Models
Authors: Wong Louis Ngai Yuen , Zhang Yahui 
Published: September 2019

AbstractGrowth and connection of preexisting fractures have been recognized as the driving mechanism of rock fracturing. This paper aims at throwing light on the geological implications of the fracturing behavior in pre‐cracked rock observed in rock mechanics‐oriented experiments, by numerical interpretation on the interaction of en echelon fractures. To properly simulate grain crushing involved in cataclastic deformation of nonporous rocks, a sophisticated numerical scheme incorporating rock morphology and crystallography into the grain‐based model is proposed. In line with a previous experimental study, seven grain‐based models with different configurations of en echelon flaws are numerically tested under uniaxial compression. The key results are (1) evaluation of the influences of preexisting flaws on mechanical properties and damage degree of the host rock, (2) visualization of the microfracture process zone into visible cracks, and (3) generalization of three different patterns of major fracture formation from en echelon fractures, during which the ratio of the number of intergranular to intragranular microcracks is used for evaluation of the cataclastic deformation process and the stress level. Based on the numerical results, we provide valuable interpretation on (1) the field occurrence of strike‐slip fault system with typical fracturing features, focusing on the effects of the sense of left or right stepping and the degrees of separation/overlap of the master fractures, and (2) three different mechanisms of fault formation from preexisting fractures. As an initial attempt to relate rock fracturing observed in laboratory experiments with the field occurrence, capabilities and limitations of this study are also presented.
Allele-specific expression and high-throughput reporter assay reveal functional genetic variants associated with alcohol use disorders
Authors: Rao Xi , Thapa Kriti S. , Chen Andy B. , Lin Hai , Gao Hongyu , Reiter Jill L. , Hargreaves Katherine A. , Ipe Joseph , Lai Dongbing , Xuei Xiaoling , Wang Yue , Gu Hongmei , Kapoor Manav , Farris Sean P. , Tischfield Jay , Foroud Tatiana , Goate Alison M. , Skaar Todd C. , Mayfield R. Dayne , Edenberg Howard J. , Liu Yunlong 
Published: September 2019

AbstractGenome-wide association studies (GWAS) of complex traits, such as alcohol use disorders (AUD), usually identify variants in non-coding regions and cannot by themselves distinguish whether the associated variants are functional or in linkage disequilibrium with the functional variants. Transcriptome studies can identify genes whose expression differs between alcoholics and controls. To test which variants associated with AUD may cause expression differences, we integrated data from deep RNA-seq and GWAS of four postmortem brain regions from 30 subjects with AUD and 30 controls to analyze allele-specific expression (ASE). We identified 88 genes with differential ASE in subjects with AUD compared to controls. Next, to test one potential mechanism contributing to the differential ASE, we analyzed single nucleotide polymorphisms (SNPs) in the 3′ untranslated regions (3′UTR) of these genes. Of the 88 genes with differential ASE, 61 genes contained 437 SNPs in the 3′UTR with at least one heterozygote among the subjects studied. Using a modified PASSPORT-seq (parallel assessment of polymorphisms in miRNA target-sites by sequencing) assay, we identified 25 SNPs that affected RNA levels in a consistent manner in two neuroblastoma cell lines, SH-SY5Y and SK-N-BE(2). Many of these SNPs are in binding sites of miRNAs and RNA-binding proteins, indicating that these SNPs are likely causal variants of AUD-associated differential ASE. In sum, we demonstrate that a combination of computational and experimental approaches provides a powerful strategy to uncover functionally relevant variants associated with the risk for AUD.
Macrophage spatial heterogeneity in gastric cancer defined by multiplex immunohistochemistry
Authors: Huang Yu-Kuan , Wang Minyu , Sun Yu , Di Costanzo Natasha , Mitchell Catherine , Achuthan Adrian , Hamilton John A. , Busuttil Rita A. , Boussioutas Alex 
Published: September 2019

AbstractTumor-associated macrophages (TAMs), one of the most abundant immune components in gastric cancer (GC), are difficult to characterize due to their heterogeneity. Multiple approaches have been used to elucidate the issue, however, due to the tissue-destructive nature of most of these methods, the spatial distribution of TAMs in situ remains unclear. Here we probe the relationship between tumor context and TAM heterogeneity by multiplex immunohistochemistry of 56 human GC cases. Using distinct expression marker profiles on TAMs, we report seven predominant populations distributed between tumor and non-tumor tissue. TAM population-associated gene signatures reflect their heterogeneity and polarization in situ. Increased density of CD163+ (CD206−) TAMs with concurrent high CD68 expression is associated with upregulated immune-signaling and improved patient survival by univariate, but not multivariate analysis. CD68-only and CD206+ TAMs are correlated with high PDL1 expression.
Mechanical-force-induced non-local collective ferroelastic switching in epitaxial lead-titanate thin films
Authors: Lu Xiaoyan , Chen Zuhuang , Cao Ye , Tang Yunlong , Xu Ruijuan , Saremi Sahar , Zhang Zhan , You Lu , Dong Yongqi , Das Sujit , Zhang Hangbo , Zheng Limei , Wu Huaping , Lv Weiming , Xie Guoqiang , Liu Xingjun , Li Jiangyu , Chen Lang , Chen Long-Qing , Cao Wenwu , Martin Lane W. 
Published: September 2019

AbstractFerroelastic switching in ferroelectric/multiferroic oxides plays a crucial role in determining their dielectric, piezoelectric, and magnetoelectric properties. In thin films of these materials, however, substrate clamping is generally thought to limit the electric-field- or mechanical-force-driven responses to the local scale. Here, we report mechanical-force-induced large-area, non-local, collective ferroelastic domain switching in PbTiO3 epitaxial thin films by tuning the misfit-strain to be near a phase boundary wherein c/a and a1/a2 nanodomains coexist. Phenomenological models suggest that the collective, c-a-c-a ferroelastic switching arises from the small potential barrier between the degenerate domain structures, and the large anisotropy of a and c domains, which collectively generates much larger response and large-area domain propagation. Large-area, non-local response under small stimuli, unlike traditional local response to external field, provides an opportunity of unique response to local stimuli, which has potential for use in high-sensitivity pressure sensors and switches.
A dual role of prestimulus spontaneous neural activity in visual object recognition
Authors: Podvalny Ella , Flounders Matthew W. , King Leana E. , Holroyd Tom , He Biyu J. 
Published: September 2019

AbstractVision relies on both specific knowledge of visual attributes, such as object categories, and general brain states, such as those reflecting arousal. We hypothesized that these phenomena independently influence recognition of forthcoming stimuli through distinct processes reflected in spontaneous neural activity. Here, we recorded magnetoencephalographic (MEG) activity in participants (N = 24) who viewed images of objects presented at recognition threshold. Using multivariate analysis applied to sensor-level activity patterns recorded before stimulus presentation, we identified two neural processes influencing subsequent subjective recognition: a general process, which disregards stimulus category and correlates with pupil size, and a specific process, which facilitates category-specific recognition. The two processes are doubly-dissociable: the general process correlates with changes in criterion but not in sensitivity, whereas the specific process correlates with changes in sensitivity but not in criterion. Our findings reveal distinct mechanisms of how spontaneous neural activity influences perception and provide a framework to integrate previous findings.
Cyclic two-step electrolysis for stable electrochemical conversion of carbon dioxide to formate
Authors: Lee Chan Woo , Cho Nam Heon , Nam Ki Tae , Hwang Yun Jeong , Min Byoung Koun 
Published: September 2019

AbstractPd metal and Pd-based alloys are ideal catalysts that allow for the electrochemical conversion of CO2 to HCOO− at almost zero-overpotential with high selectivity, but catalyst degradation caused by concurrent CO poisoning limits their practical implementation. Here, we demonstrate that cyclic two-step electrolysis, by applying the reduction and oxidation potentials alternately, achieves 100% current density stability and 97.8% selectivity toward HCOO− production for at least 45 h. The key idea for achieving the reliability is based on the selective removal of CO by controlling the parameters during the oxidation step, which utilizes the different reversibility of HCOO− and CO production reactions. Furthermore, it is found that potentiostatic electrolysis causes CO adsorption and subsequent dehydridation, which in turn lowers HCOO− selectivity. Our work provides a system-level strategy for solving the poisoning issue that is inevitable in many electrocatalytic reactions.
Frequency stabilization and noise-induced spectral narrowing in resonators with zero dispersion
Authors: Huang L. , Soskin S. M. , Khovanov I. A. , Mannella R. , Ninios K. , Chan H. B. 
Published: September 2019

AbstractMechanical resonators are widely used as precision clocks and sensitive detectors that rely on the stability of their eigenfrequencies. The phase noise is determined by different factors including thermal noise, frequency noise of the resonator and noise in the feedback circuitry. Increasing the vibration amplitude can mitigate some of these effects but the improvements are limited by nonlinearities that are particularly strong for miniaturized micro- and nano-mechanical systems. Here we design a micromechanical resonator with non-monotonic dependence of the eigenfrequency on energy. Near the extremum, where the dispersion of the eigenfrequency is zero, the system regains certain characteristics of a linear resonator, albeit at large amplitudes. The spectral peak undergoes narrowing when the noise intensity is increased. With the resonator serving as the frequency-selecting element in a feedback loop, the phase noise at the extremum amplitude is ~3 times smaller than the minimal noise in the conventional nonlinear regime.
Microscale pH variations during drying of soils and desert biocrusts affect HONO and NH3 emissions
Authors: Kim Minsu , Or Dani 
Published: September 2019

AbstractMicroscale interactions in soil may give rise to highly localised conditions that disproportionally affect soil nitrogen transformations. We report mechanistic modelling of coupled biotic and abiotic processes during drying of soil surfaces and biocrusts. The model links localised microbial activity with pH variations within thin aqueous films that jointly enhance emissions of nitrous acid (HONO) and ammonia (NH3) during soil drying well above what would be predicted from mean hydration conditions and bulk soil pH. We compared model predictions with case studies in which reactive nitrogen gaseous fluxes from drying biocrusts were measured. Soil and biocrust drying rates affect HONO and NH3 emission dynamics. Additionally, we predict strong effects of atmospheric NH3 levels on reactive nitrogen gas losses. Laboratory measurements confirm the onset of microscale pH localisation and highlight the critical role of micro-environments in the resulting biogeochemical fluxes from terrestrial ecosystems.
Adiabatic two-qubit gates in capacitively coupled quantum dot hybrid qubits
Authors: Frees Adam , Mehl Sebastian , Gamble John King , Friesen Mark , Coppersmith S. N. 
Published: September 2019

AbstractThe ability to tune qubits to flat points in their energy dispersions (“sweet spots”) is an important tool for mitigating the effects of charge noise and dephasing in solid-state devices. However, the number of derivatives that must be simultaneously set to zero grows exponentially with the number of coupled qubits, making the task untenable for as few as two qubits. This is a particular problem for adiabatic gates, due to their slower speeds. Here, we propose an adiabatic two-qubit gate for quantum dot hybrid qubits, based on the tunable, electrostatic coupling between distinct charge configurations. We confirm the absence of a conventional sweet spot, but show that controlled-Z (CZ) gates can nonetheless be optimized to have fidelities of ~99% for a typical level of quasistatic charge noise (σε ≃ 1 μeV). We then develop the concept of a dynamical sweet spot (DSS), for which the time-averaged energy derivatives are set to zero, and identify a simple pulse sequence that achieves an approximate DSS for a CZ gate, with a 5× improvement in the fidelity. We observe that the results depend on the number of tunable parameters in the pulse sequence, and speculate that a more elaborate sequence could potentially attain a true DSS.
Logical design of oral glucose ingestion pattern minimizing blood glucose in humans
Authors: Fujii Masashi , Murakami Yohei , Karasawa Yasuaki , Sumitomo Yohei , Fujita Suguru , Koyama Masanori , Uda Shinsuke , Kubota Hiroyuki , Inoue Hiroshi , Konishi Katsumi , Oba Shigeyuki , Ishii Shin , Kuroda Shinya 
Published: September 2019

AbstractExcessive increase in blood glucose level after eating increases the risk of macroangiopathy, and a method for not increasing the postprandial blood glucose level is desired. However, a logical design method of the dietary ingestion pattern controlling the postprandial blood glucose level has not yet been established. We constructed a mathematical model of blood glucose control by oral glucose ingestion in three healthy human subjects, and predicted that intermittent ingestion 30 min apart was the optimal glucose ingestion patterns that minimized the peak value of blood glucose level. We confirmed with subjects that this intermittent pattern consistently decreased the peak value of blood glucose level. We also predicted insulin minimization pattern, and found that the intermittent ingestion 30 min apart was optimal, which is similar to that of glucose minimization pattern. Taken together, these results suggest that the glucose minimization is achieved by suppressing the peak value of insulin concentration, rather than by enhancing insulin concentration. This approach could be applied to design optimal dietary ingestion patterns.
Flux sampling is a powerful tool to study metabolism under changing environmental conditions
Authors: Herrmann Helena A. , Dyson Beth C. , Vass Lucy , Johnson Giles N. , Schwartz Jean-Marc 
Published: September 2019

AbstractThe development of high-throughput ‘omic techniques has sparked a rising interest in genome-scale metabolic models, with applications ranging from disease diagnostics to crop adaptation. Efficient and accurate methods are required to analyze large metabolic networks. Flux sampling can be used to explore the feasible flux solutions in metabolic networks by generating probability distributions of steady-state reaction fluxes. Unlike other methods, flux sampling can be used without assuming a particular cellular objective. We have undertaken a rigorous comparison of several sampling algorithms and concluded that the coordinate hit-and-run with rounding (CHRR) algorithm is the most efficient based on both run-time and multiple convergence diagnostics. We demonstrate the power of CHRR by using it to study the metabolic changes that underlie photosynthetic acclimation to cold ofArabidopsis thalianaplant leaves. In combination with experimental measurements, we show how the regulated interplay between diurnal starch and organic acid accumulation defines the plant acclimation process. We confirm fumarate accumulation as a requirement for cold acclimation and further predictγ–aminobutyric acid to have a key role in metabolic signaling under cold conditions. These results demonstrate how flux sampling can be used to analyze the feasible flux solutions across changing environmental conditions, whereas eliminating the need to make assumptions which introduce observer bias.
Life cycle progression and sexual development of the apicomplexan parasite Cryptosporidium parvum
Authors: Tandel Jayesh , English Elizabeth D. , Sateriale Adam , Gullicksrud Jodi A. , Beiting Daniel P. , Sullivan Megan C. , Pinkston Brittain , Striepen Boris 
Published: September 2019

AbstractThe apicomplexan parasite Cryptosporidium is a leading global cause of severe diarrhoeal disease and an important contributor to early childhood mortality. Currently, there are no fully effective treatments or vaccines available. Parasite transmission occurs through ingestion of oocysts, through either direct contact or consumption of contaminated water or food. Oocysts are meiotic spores and the product of parasite sex. Cryptosporidium has a single-host life cycle in which both asexual and sexual processes occur in the intestine of infected hosts. Here, we genetically engineered strains of Cryptosporidium to make life cycle progression and parasite sex tractable. We derive reporter strains to follow parasite development in culture and in infected mice and define the genes that orchestrate sex and oocyst formation through mRNA sequencing of sorted cells. After 2 d, parasites in cell culture show pronounced sexualization, but productive fertilization does not occur and infection falters. By contrast, in infected mice, male gametes successfully fertilize female parasites, which leads to meiotic division and sporulation. To rigorously test for fertilization, we devised a two-component genetic-crossing assay using a reporter that is activated by Cre recombinase. Our findings suggest obligate developmental progression towards sex in Cryptosporidium, which has important implications for the treatment and prevention of the infection.