bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclostratigraphy, stratigraphic gaps and the duration of the Hettangian Stage (Jurassic): insights from the Blue Lias Formation of southern Britain
Authors: Weedon Graham P. , Page Kevin N. , Jenkyns Hugh C. 
Published: December 2018

AbstractThe lithostratigraphic characteristics of the iconic Blue Lias Formation of southern Britain are influenced by sedimentation rates and stratigraphic gaps. Evidence for regular sedimentary cycles is reassessed using logs of magnetic susceptibility from four sites as an inverse proxy for carbonate content. Standard spectral analysis, including allowing for false discovery rates, demonstrates several scales of regular cyclicity in depth. Bayesian probability spectra provide independent confirmation of at least one scale of regular cyclicity at all sites. The frequency ratios between the different scales of cyclicity are consistent with astronomical forcing of climate at the periods of the short eccentricity, obliquity and precession cycles. Using local tuned time scales, 62 ammonite biohorizons have minimum durations of 0.7 to 276 ka, with 94% of them <41 ka. The duration of the Hettangian Stage is ≥2.9 Ma according to data from the West Somerset and Devon/Dorset coasts individually, increasing to ≥3.7 Ma when combined with data from Glamorgan and Warwickshire. A composite time scale, constructed using the tuned time scales plus correlated biohorizon limits treated as time lines, allows for the integration of local stratigraphic gaps. This approach yields an improved duration for the Hettangian Stage of ≥4.1 Ma, a figure that is about twice that suggested in recent time scales.
An evaluation of efficiency in dairy production using structural equation modelling
Authors: Drews J. , Czycholl I. , Junge W. , Krieter J. 
Published: December 2018

AbstractOptimization of production factors plays a central role in efficient milk production operations. Causal relationships between production parameters (health, fertility, feeding, performance and farm size) on the one hand and efficiency parameters on the other have been identified in several studies. In recent years, structural equation modelling (SEM) has not only gained importance in agriculture but also in milk production, providing the opportunity to investigate multilateral relationships. Additionally, SEM enables an estimation of parameters which are not themselves measurable, the so-called latent variables. The current study was based on the data of 943 branch settlements (including the years 2012 and 2013) of dairy farms keeping German Holstein cows in Schleswig-Holstein (Northern Germany) which provided a combination of the structural parameters, economic parameters and biological performance of the farms. An SEM using this combined data was applied to investigate the complexity of influences on efficiency parameters in milk production. Efficiency was sub-divided into and evaluated by two effect variables (economic efficiency and biological efficiency). Economic efficiency was defined as a conventional efficiency assessment criterion from full-cost accounting, whereas biological efficiency was used to evaluate the quality of herd management. Performance was identified as the key parameter for independent evaluation of efficiency by assessing biological (γ41 = 0.644) or economic efficiency (γ42 = 0.266). The SEM explained more than three times higher proportion of the variance in biological efficiency than in economic efficiency. The investigation proved the eligibility of partial least squares SEM for the evaluation of efficiency in milk production.
RecA kinetically selects homologous DNA by testing a five- or six-nucleotide matching sequence and deforming the second DNA
Authors: Takahashi Masayuki 
Published: December 2018

AbstractRecA family proteins pair two DNAs with the same sequence to promote strand exchange during homologous recombination. To understand how RecA proteins search for and recognize homology, we sought to determine the length of homologous sequence that permits RecA to start its reaction. Specifically, we analyzed the effect of sequence heterogeneity on the association rate of homologous DNA with RecA/single-stranded DNA complex. We assumed that the reaction can start with equal likelihood at any point in the DNA, and that sequence heterogeneity abolishes some possible initiation sites. This analysis revealed that the effective recognition size is five or six nucleotides, larger than the three nucleotides recognized by a RecA monomer. Because the first DNA is elongated 1.5-fold by intercalation of amino acid residues of RecA every three bases, the second bound DNA must be elongated to pair with the first. Because this length is similar to estimates based on the strand-exchange reaction or DNA pair formation, the homology test is likely to occur primarily at the association step. The energetic difference due to the absence of hydrogen bonding is too small to discriminate single-nucleotide heterogeneity over a five- or six-nucleotide sequence. The selection is very likely to be made kinetically, and probably involves some structural factor other than Watson–Crick hydrogen bonding. It would be valuable to determine whether this is also the case for other biological reactions involving DNA base complementarity, such as replication, transcription, and translation.
“The God of This Lower World”: Leo Strauss's Critique of Historicism inNatural Right and History
Authors: Shaw Beau 
Published: December 2018

AbstractThis paper offers a new account of Leo Strauss's critique of historicism inNatural Right and History. According to the general view of this critique, Strauss tries to show that historicism wrongly denies the possibility of knowledge of universal and unchangeable principles of right. I argue that this view only reflects Strauss's exoteric critique of historicism, and that, apart from it, he gives an esoteric critique. According to this esoteric critique, historicism ignores the necessity of prudence, in the sense of making “concrete decisions” which suspend universal and unchangeable principles of right. In this light, I also show that Strauss's critique of historicism depends on Carl Schmitt's concept of the “decision,” but that Strauss simultaneously critiques Schmitt inNatural Right and History.
Interference of Palmer amaranth (Amaranthus palmeri) Density in Grafted and Nongrafted Watermelon
Authors: Bertucci Matthew B. , Jennings Katherine M. , Monks David W. , Schultheis Jonathan R. , Louws Frank J. , Jordan David L. 
Published: December 2018

AbstractWatermelon [Citrullus lanatus(Thunb.) Matsum & Nakai] grafting is commonly used for management of diseases caused by soilborne pathogens; however, little research exists describing the effect of grafting on the weed-competitive ability of watermelon. Field experiments determined the response in yield, fruit number, and fruit quality of grafted and nongrafted watermelon exposed to increasing densities of Palmer amaranth (Amaranthus palmeriS. Watson). Grafting treatments included ‘Exclamation’ triploid (seedless) watermelon grafted on two interspecific hybrid squash rootstocks ‘Carnivor’ and ‘Kazako’, with nongrafted Exclamation as the control. Weed treatments includedA. palmeriat densities of 1, 2, 3, and 4A. palmeriplants per watermelon planting hole (0.76-m row) and a weed-free control. IncreasingA. palmeridensities caused significant reductions (P <0.05) in marketable watermelon yield and marketable fruit number. Watermelon yield reduction was described by a rectangular hyperbola model, and 4A. palmeriplants planting hole−1reduced marketable yield 41%, 38%, and 65% for Exclamation, Carnivor, and Kazako, respectively. Neither grafting treatment norA. palmeridensity had a biologically meaningful effect on soluble solids content or on the incidence of hollow heart in watermelon fruit.Amaranthus palmeriseed and biomass production was similar across weed population densities, but seed number per femaleA. palmeridecreased according to a two-parameter exponential decay equation. Thus, increasing weed population densities resulted in increased intraspecific competition amongA. palmeriplants. While grafting may offer benefits for disease resistance, no benefits regarding weed-competitive ability were observed, and a consistent yield penalty was associated with grafting, even in weed-free treatments.
Long‐Term Changes in Wintertime Temperature Extremes in Moscow and Their Relation to Regional Atmospheric Dynamics
Authors: Zyulyaeva Yulia A. , Studholme Joshua H. P. , Zveryaev Igor I. 
Published: December 2018

AbstractInterannual variability and long‐term changes in winter air temperature extremes in Moscow (1949–2017) are investigated using observational and reanalysis data. Significant interdecadal changes in principal characteristics of temperature extremes are revealed. Strong warming (0.50 °K per decade) is identified contrasting to the previously identified summer trend of 0.25 °K per decade. This is attributable to middle‐to‐late winter. Winter and summer daily air temperature variabilities are fundamentally different with wintertime anomalies strongly negatively skewed, while summer displays Gaussian variability. A reduction in the number of cold days and an increase in warm days in December and March are found. In January and February, the probability of warm extremes increases, while the probability of cold extremes remains constant. Intensification of January extremes (cold and warm) is revealed along with daily temperature variability reduction. In aggregate, potential shortening of Moscow's winter season, suppression of the previously strong seasonal cycle in daily temperature variability, and intensification of midwinter extremes are identified. Dynamical linkages are found to North Atlantic and Mediterranean storm track variability as well as synoptic activity over the Barents‐Kara Seas. Lagrangian analysis shows associations of wintertime extreme warm events to air masses originating over the North Atlantic and Mediterranean regions. Air masses implicated in cold extremes are mostly of Siberian and Arctic origin. On interannual time scales cold event frequency in Moscow is impacted by the negative phase of North Atlantic Oscillation, whereas frequency of warm events is influenced by the positive phase of North Atlantic Oscillation and the negative phase of Scandinavian teleconnection.
11 Years of Rayleigh Lidar Observations of Gravity Wave Activity Above the Southern Tip of South America
Authors: Llamedo P. , Salvador J. , de la Torre A. , Quiroga J. , Alexander P. , Hierro R. , Schmidt T. , Pazmiño A. , Quel E. 
Published: December 2018

AbstractGravity wave (GW) activity is analyzed using temperature (T) data retrieved from a Rayleigh light detection and ranging (lidar) at Río Gallegos, Argentina (51.6°S, 69.3°W). GW characteristics are derived from 302 nights of observations providing more than 1,018 hr of high‐resolution lidar data between 20‐ and 56‐km height from August 2005 to December 2015. T measurements are performed by a Differential Absorption Lidar instrument. This lidar was the southernmost outside Antarctica until the end of 2017. Río Gallegos is an exceptional place to observe large amplitude GW. Every lidar measurement is classified according to its relative position to the polar vortex. The lidar measurements are compared with collocated Sounding of the Atmosphere using Broadband Emission Radiometry and Global Positioning System‐Radio Occultation data. The different instruments show different windows of the GW spectrum, providing complementary observations. In general, the geometric mean of the specific GW potential energy (PE) is larger during winter and spring than during summer and autumn. The largest geometric mean of PE is found inside the vortex and decreases monotonically at its edge, outside it and when there is no vortex. The same behavior is observed with satellite data. On average, it can be seen that lidar observations provide larger PE values than limb sounding measurements. From a Morlet continuous wavelet transform analysis, three distinct modes are captured from Sounding of the Atmosphere using Broadband Emission Radiometry and from Global Positioning System‐Radio Occultation data at the upper and lower stratosphere, respectively. In particular, a systematic 3.5‐ to 4‐year oscillation, possibly related to El Niño–Southern Oscillation is observed.
The Role of Convective Self‐Aggregation in Extreme Instantaneous Versus Daily Precipitation
Authors: Bao Jiawei , Sherwood Steven C. 
Published: December 2018

AbstractThe impacts of convective self‐aggregation on extreme precipitation and updraft velocity are investigated by using the Weather Research and Forecasting Model in the idealized setting of radiative‐convective equilibrium with a 3‐km horizontal resolution. Aggregated and unaggregated states are achieved by conducting simulations with fully interactive and fixed radiation, respectively. We find that convective self‐aggregation has a negligible impact on extreme instantaneous precipitation but weakens the extreme updrafts and condensation, indicating a negative dynamical contribution from aggregation to extreme instantaneous precipitation. However, this is balanced by higher precipitation efficiency to maintain the same extreme instantaneous precipitation. This balance occurs because updrafts decrease mainly above the freezing level, suppressing graupel production. As graupel has a longer residence time than rain, less graupel formation with aggregation implies enhanced instantaneous local precipitation efficiency. Peak updraft velocity scales with the vertical integral of buoyancy, measured with respect to the local prestorm environment. This local environment is warmer and moister at middle and high levels when convection is aggregated compared to when it is unaggregated, reducing the buoyancy and updraft velocity. Unlike extreme instantaneous precipitation, extreme daily precipitation is stronger in aggregated states, as self‐aggregation localizes and sustains updrafts and condensation in relatively fixed locations. Our results imply that extreme instantaneous precipitation is more sensitive to microphysical processes while extreme daily precipitation is more linked to the degree of aggregation.
Bayesian Analyses of 17 Winters of Water Vapor Fluxes Show Bark Beetles Reduce Sublimation
Authors: Frank John M. , Massman William J. , Ewers Brent E. , Williams David G. 
Published: December 2018

AbstractSublimation is an important hydrological flux in cold, snow‐dominated ecosystems. In high‐elevation spruce‐fir forests of western North America, spruce beetle outbreaks have killed trees, reduced the canopy, and altered processes that control sublimation. We evaluated two hypotheses related to effects of disturbance on sublimation in this ecosystem: (1) the dominant source for sublimation is canopy intercepted snow and (2) the loss of canopy following a beetle disturbance leads to less total sublimation. To incorporate uncertainty hierarchically across multiple data sources and address phenomenological parsimony, Bayesian statistics were used to analyze 17 years (2000–2016) of winter eddy covariance flux data at the Glacier Lakes Ecosystem Experiments Sites AmeriFlux sites where a spruce beetle outbreak caused 75–85% basal area mortality. Our analysis revealed that resistances to sublimate snow from the canopy were an order of magnitude less than from the snowpack, and the maximum snow loading capacity in disturbed canopies was reduced to 34% of its pre‐outbreak value. Total sublimation has decreased since 2010, 2 years after the main outbreak, declining 24% (with a 95% credible interval, C.I., between 18% and 38%) during 2014–2016 due to a 32% decrease in canopy sublimation. Snowpack sublimation only increased 3% over this period. With less total sublimation, the forest retained 6.1% (4.5–12.3% C.I.) more snowpack mass or equivalently 4.4% (3.2–8.8 C.I.) of the annual precipitation. Considering tree growth and ecological succession are slow in spruce‐fir forests, this decrease in sublimation should persist as an increased snowpack for decades, with substantial impacts on catchment hydrologic processes and potentially streamflow.
Atypical GATA transcription factor TRPS1 represses gene expression by recruiting CHD4/NuRD(MTA2) and suppresses cell migration and invasion by repressing TP63 expression
Authors: Wang Yuzhi , Lin Xue , Gong Xue , Wu Lele , Zhang Jun , Liu Weiguang , Li Jian , Chen Liming 
Published: December 2018

AbstractTranscriptional repressor GATA binding 1 (TRPS1), an atypical GATA transcription factor, functions as a transcriptional repressor and is also implicated in human cancers. However, the underlying mechanism of TRPS1 contributing to malignancy remains obscure. In the current study, we report that TRPS1 recognizes both gene proximal and distal transcription start site (TSS) sequences to repress gene expression. Co-IP mass spectrometry and biochemical studies showed that TRPS1 binds to CHD4/NuRD(MTA2). Genome-wide and molecular studies revealed that CHD4/NuRD(MTA2) is required for TRPS1 transcriptional repression. Mechanically, TRPS1 and CHD4/NuRD(MTA2) form precision-guided transcriptional repression machinery in which TRPS1 guides the machinery to specific target sites by recognizing GATA elements, and CHD4/NuRD(MTA2) represses the transcription of target genes. Furthermore, TP63 was identified and validated to be a direct target of TRPS1-CHD4/NuRD(MTA2) complex, which represses TP63 expression by involving decommission of TP63 enhancer in the described precision-guided manner, leading to a reduction of the ΔNp63 level and contributing to migration and invasion of cancer cells.
The gut microbiome is required for full protection against acute arsenic toxicity in mouse models
Authors: Coryell Michael , McAlpine Mark , Pinkham Nicholas V. , McDermott Timothy R. , Walk Seth T. 
Published: December 2018

AbstractArsenic poisons an estimated 200 million people worldwide through contaminated food and drinking water. Confusingly, the gut microbiome has been suggested to both mitigate and exacerbate arsenic toxicity. Here, we show that the microbiome protects mice from arsenic-induced mortality. Both antibiotic-treated and germ-free mice excrete less arsenic in stool and accumulate more arsenic in organs compared to control mice. Mice lacking the primary arsenic detoxification enzyme (As3mt) are hypersensitive to arsenic after antibiotic treatment or when derived germ-free, compared to wild-type and/or conventional counterparts. Human microbiome (stool) transplants protect germ-free As3mt-KO mice from arsenic-induced mortality, but protection depends on microbiome stability and the presence of specific bacteria, including Faecalibacterium. Our results demonstrate that both a functional As3mt and specific microbiome members are required for protection against acute arsenic toxicity in mouse models. We anticipate that the gut microbiome will become an important explanatory factor of disease (arsenicosis) penetrance in humans, and a novel target for prevention and treatment strategies.
Transverse spin forces and non-equilibrium particle dynamics in a circularly polarized vacuum optical trap
Authors: Svak V. , Brzobohatý O. , Šiler M. , Jákl P. , Kaňka J. , Zemánek P. , Simpson S. H. 
Published: December 2018

AbstractWe provide a vivid demonstration of the mechanical effect of transverse spin momentum in an optical beam in free space. This component of the Poynting momentum was previously thought to be virtual, and unmeasurable. Here, its effect is revealed in the inertial motion of a probe particle in a circularly polarized Gaussian trap, in vacuum. Transverse spin forces combine with thermal fluctuations to induce a striking range of non-equilibrium phenomena. With increasing beam power we observe (i) growing departures from energy equipartition, (ii) the formation of coherent, thermally excited orbits and, ultimately, (iii) the ejection of the particle from the trap. As well as corroborating existing measurements of spin momentum, our results reveal its dynamic effect. We show how the under-damped motion of probe particles in structured light fields can expose the nature and morphology of optical momentum flows, and provide a testbed for elementary non-equilibrium statistical mechanics.
Flavin-based metabolic cycles are integral features of growth and division in single yeast cells
Authors: Baumgartner Bridget L. , O’Laughlin Richard , Jin Meng , Tsimring Lev S. , Hao Nan , Hasty Jeff 
Published: December 2018

AbstractThe yeast metabolic cycle (YMC) is a fascinating example of biological organization, in which cells constrain the function of specific genetic, protein and metabolic networks to precise temporal windows as they grow and divide. However, understanding the intracellular origins of the YMC remains a challenging goal, as measuring the oxygen oscillations traditionally associated with it requires the use of synchronized cultures growing in nutrient-limited chemostat environments. To address these limitations, we used custom-built microfluidic devices and time-lapse fluorescence microscopy to search for metabolic cycling in the form of endogenous flavin fluorescence in unsynchronized single yeast cells. We uncovered robust and pervasive metabolic cycles that were synchronized with the cell division cycle (CDC) and oscillated across four different nutrient conditions. We then studied the response of these metabolic cycles to chemical and genetic perturbations, showing that their phase synchronization with the CDC can be altered through treatment with rapamycin, and that metabolic cycles continue even in respiratory deficient strains. These results provide a foundation for future studies of the physiological importance of metabolic cycles in processes such as CDC control, metabolic regulation and cell aging.
Contributions of default mode network stability and deactivation to adolescent task engagement
Authors: McCormick Ethan M. , Telzer Eva H. 
Published: December 2018

AbstractOut of the several intrinsic brain networks discovered through resting-state functional analyses in the past decade, the default mode network (DMN) has been the subject of intense interest and study. In particular, the DMN shows marked suppression during task engagement, and has led to hypothesized roles in internally-directed cognition that need to be down-regulated in order to perform goal-directed behaviors. Previous work has largely focused on univariate deactivation as the mechanism of DMN suppression. However, given the transient nature of DMN down-regulation during task, an important question arises: Does the DMN need to be strongly, or more stably suppressed to promote successful task learning? In order to explore this question, 65 adolescents (Mage = 13.32; 21 females) completed a risky decision-making task during an fMRI scan. We tested our primary question by examining individual differences in absolute level of deactivation against the stability of activation across time in predicting levels of feedback learning on the task. To measure stability, we utilized a model-based functional connectivity approach that estimates the stability of activation across time within a region. In line with our hypothesis, the stability of activation in default mode regions predicted task engagement over and above the absolute level of DMN deactivation, revealing a new mechanism by which the brain can suppress the influence of brain networks on behavior. These results also highlight the importance of adopting model-based network approaches to understand the functional dynamics of the brain.