bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of pre‐treatments on bulk stable isotope ratios in fish samples: A cautionary note for studies comparisons
Authors: Connan Maëlle , Hall Grant , Smale Malcolm 
Published: November 2018

RationaleStable isotope analysis (SIA) has revolutionised ecological studies over the past thirty years. One of the major fields where SIA is applied in the marine environment is related to the definition of ecosystem structure and function. With marine top predators such as sharks, SIA is a method of choice because tissue samples can be collected without the sacrifice of the animal. In elasmobranch research, the influence of compounds such as urea, trimethylamine oxide and lipids must be considered when using stable isotopes as ecological markers. Currently, a range of pre‐treatments are used to chemically remove these molecules prior to SIA.MethodsThis study investigated the impact of eleven commonly used pre‐treatments on carbon and nitrogen contents and C:N atomic ratio, as well as carbon and nitrogen SI ratios in elasmobranch tissues and its prey, measured by isotope ratio mass spectrometry. Three tissues were tested: blood and muscle of the ragged‐tooth shark Carcharias taurus, and muscle of one teleost species, the Cape knifejaw Oplegnathus conwayi.ResultsCompared with untreated samples, no trend or generalisation could be highlighted with the influence of pre‐treatments being species‐, tissue‐ and chemical‐element‐dependent. For the δ13C and δ15N values, differences among pre‐treatments were as high as 3‰, therefore potentially leading to erroneous ecological interpretation.ConclusionsThe chemical properties of compounds (e.g. urea, lipids) combined with the polarity of solutions (e.g. water, solvents) explained a large part of these observations. This study highlights that pre‐treatments need to be considered especially when comparing carbon and nitrogen stable isotope ratios between studies. The results of this study provide a call to all stable isotope researchers to make a concerted effort to standardise pre‐treatment methods. This is crucial as global reviews are becoming increasingly more informative.
Semi‐global containment control for linear systems in the presence of actuator position and rate saturation
Authors: Zhao Zhiyun , Shi Hongbo 
Published: November 2018

SummaryThis paper studies the semi‐global containment control problem for a group of general linear systems in the presence of actuator position and rate saturation. Both a state feedback containment control algorithm and an output feedback containment algorithm are constructed for each follower agent in the system by using low gain approach. We show that the states of all follower agents will converge to the convex hull formed by the leader agents asymptotically under these control algorithms when the communication topology among follower agents is a connected undirected graph and each leader agent is a neighbor of at least one follower agent. Simulation results illustrate the theoretical results.
Second‐order effects of CEO characteristics: How rivals' perceptions of CEOs as submissive and provocative precipitate competitive attacks
Authors: Hill Aaron D. , Recendes Tessa , Ridge Jason W. 
Published: November 2018

Research SummaryIntegrating victimization into competitive dynamics and upper echelons theorizing, we develop and test theory articulating how rivals' perceptions of a CEO precipitate attacks on the CEO's firm. Rather than treating CEOs' characteristics solely as perpetrating action (a first‐order effect, like research integrating upper echelons into competitive dynamics), we argue firms with CEOs possessing characteristics perceived as more submissive or more provocative are subject to more competitive actions directed toward their firms (a second‐order effect, like victimization research). Empirical analyses of a sample of Fortune 500 CEOs supports our theorizing while interviews of executives corroborate our premise as well. Our framework offers a more complete and socialized understanding of CEOs' roles in competitive dynamics, providing both theoretical and practical insights as well as future research avenues.Managerial SummaryWe articulate how CEOs possessing certain psychological, behavioral, and social characteristics may unknowingly precipitate competitive attacks on their firms. Our explanation integrates insights from victimology which explain how individuals are subject to more attacks if they possess characteristics others perceive as more submissive or more provocative. While prior research articulates that CEOs' characteristics affect decisions such as attacking rivals, integrating theories of victimization into this line of inquiry paints a more socialized view of why firms may be subject to competitive attacks as well. The logic and evidence we provide advances theoretical explanations of firms' competitive behaviors and executives' roles therein. At the same time, providing knowledge about how CEO characteristics precipitate competitive actions toward their firms can aid in prevention and intervention strategies.
Signatures of the genuine and matter-induced components of the CP violation asymmetry in neutrino oscillations
Authors: Bernabéu José , Segarra Alejandro 
Published: November 2018

Abstract

CP asymmetries for neutrino oscillations in matter can be disentangled into the matter-induced CPT-odd (T-invariant) component and the genuine T-odd (CPT-invariant) component. For their understanding in terms of the relevant ingredients, we develop a new perturbative expansion in both Δm
21
2
, |a| ≪ |Δm
31
2
| without any assumptions between Δm
21
2
and a, and study the subtleties of the vacuum limit in the two terms of the CP asymmetry, moving from the CPT-invariant vacuum limit a → 0 to the T-invariant limit Δm
21
2
→ 0. In the experimental region of terrestrial accelerator neutrinos, we calculate their approximate expressions from which we prove that, at medium baselines, the CPT-odd component is small and nearly δ-independent, so it can be subtracted from the experimental CP asymmetry as a theoretical background, provided the hierarchy is known. At long baselines, on the other hand, we find that (i) a Hierarchy-odd term in the CPT-odd component dominates the CP asymmetry for energies above the first oscillation node, and (ii) the CPT-odd term vanishes, independent of the CP phase δ, at E = 0.92 GeV (L/1300 km) near the second oscillation maximum, where the T-odd term is almost maximal and proportional to sin δ. A measurement of the CP asymmetry in these energy regions would thus provide separate information on (i) the neutrino mass ordering, and (ii) direct evidence of genuine CP violation in the lepton sector.
Guidelines for Perioperative Care in Elective Colorectal Surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018
Authors: Gustafsson U. O. , Scott M. J. , Hubner M. , Nygren J. , Demartines N. , Francis N. , Rockall T. A. , Young‐Fadok T. M. , Hill A. G. , Soop M. , de Boer H. D. , Urman R. D. , Chang G. J. , Fichera A. , Kessler H. , Grass F. , Whang E. E. , Fawcett W. J. , Carli F. , Lobo D. N. , Rollins K. E. , Balfour A. , Baldini G. , Riedel B. , Ljungqvist O. 
Published: November 2018

AbstractBackgroundThis is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol.MethodsA wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta‐analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.ResultsAll recommendations on ERAS® protocol items are based on best available evidence; good‐quality trials; meta‐analyses of good‐quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.ConclusionsThe evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.
Proteomic Identification of Biomarkers Associated with Eating Control and Bariatric Surgery Outcomes in Patients with Morbid Obesity
Authors: Rodríguez‐Rivera Carmen , Pérez‐García Carmen , Muñoz‐Rodríguez José Ramón , Vicente‐Rodríguez Marta , Polo Filomena , Ford Rhian‐Marie , Segura Esperanza , León Alberto , Salas Elisabet , Sáenz‐Mateos Luis , González‐Martín Carmen , Herradón Gonzalo , Beato‐Fernández Luis , Martín‐Fernández Jesús , Alguacil Luis F. 
Published: November 2018

AbstractBackgroundThe current therapeutics of morbid obesity could be significantly improved after the identification of novel biomarkers associated with the food addiction endophenotype of obesity and with bariatric surgery outcomes.MethodsWe applied differential expression proteomics and enzyme‐linked immunosorbent confirmatory assays to identify (a) proteins that varied according to loss of control over eating in morbidly obese patients and (b) proteins that varied between normoweight controls and patients before and 1 year after bariatric surgery.ResultsClusterin was the only protein that consistently varied according to eating control in patients. Patients showed increased levels of serum amyloid P protein, apolipoprotein A4, serotransferrin, complement factors B and C3 and haptoglobin with respect to controls; the levels of all these proteins tended to return to control values 1 year after surgery. In contrast, apolipoprotein A1 and transthyretin were initially downregulated in patients and were scarcely changed by surgery. Leucine‐rich alpha‐2‐glycoprotein was markedly increased in patients only after surgery.ConclusionsClusterin could be of interest as a putative biomarker for food addiction diagnosis in people with morbid obesity. In addition, postsurgical normalization of the proteins initially dysregulated in obese subjects might help monitor clinical improvements after surgery, while lasting or newly detected alterations (i.e., those affecting transthyretin and leucine‐rich alpha‐2‐glycoprotein) could reflect partial refractoriness and/or contribute to the early prediction of clinical problems.
Recent advances in the discovery and combinatorial biosynthesis of microbial 14-membered macrolides and macrolactones
Authors: Park Je Won , Yoon Yeo Joon 
Published: November 2018

Abstract
Macrolides, especially 14-membered macrolides, are a valuable group of antibiotics that originate from various microorganisms. In addition to their antibacterial activity, newly discovered 14-membered macrolides exhibit other therapeutic potentials, such as anti-proliferative and anti-protistal activities. Combinatorial biosynthetic approaches will allow us to create structurally diversified macrolide analogs, which are especially important during the emerging post-antibiotic era. This review focuses on recent advances in the discovery of new 14-membered macrolides (also including macrolactones) from microorganisms and the current status of combinatorial biosynthetic approaches, including polyketide synthase (PKS) and post-PKS tailoring pathways, and metabolic engineering for improved production together with heterologous production of 14-membered macrolides.
Uncertainty Analysis of Simulations of the Turn‐of‐the‐Century Drought in the Western United States
Authors: Anderson Gemma J. , Lucas Donald D. , Bonfils Céline 
Published: November 2018

AbstractWe perform the first uncertainty quantification analysis of the turn‐of‐the‐century drought in the western United States using a large perturbed‐parameter ensemble of the Community Atmosphere Model version 4.0 (CAM4). We develop several metrics to characterize the aridity bias, spatial extent, and tropical forcing of the drought and use statistical models to ascertain that the modeled drought was mainly sensitive to CAM4 parameters related to deep convection and clouds. Deep convection parameters account for over half the variance across the drought metrics. We employ observed estimates of these drought metrics to infer probability distributions of the model parameters that lead to a better agreement with observations, thereby providing guidance on how to improve the simulation of drought in CAM4. We find that in some cases, the suggested parameter values that improve the simulation of one drought characteristic would degrade the simulation of another, suggesting that there is a complex relationship between the model parameters and drought in the western United States. We also demonstrate reductions in the uncertainty of the drought metrics of up to 30% by constraining with observations of all metrics. Furthermore, we demonstrate for the first time that improvements to the simulation of the spatial extent of the turn‐of‐the‐century drought also lead to improvements in the spatial extent of the Australian Millennium drought, suggesting that physics of drought as encoded by the model parameters may be generalizable.
Greenhouse Gas Production and Transport in Desert Soils of the Southwestern United States
Authors: Oerter Erik , Mills Jennifer V. , Maurer Gregory E. , Lammers Laura Nielsen , Amundson Ronald 
Published: November 2018

AbstractDeserts comprise a large portion of the Earth's land area, yet their role in the fluxes and cycles of greenhouse gases is poorly known and their likely response to climate change largely unexplored. We report a reconnaissance investigation of the concentrations and fluxes of CO2, CH4, and N2O along two elevation (climate) gradients in the southwestern United States. In‐soil concentrations of CO2 increased with elevation (up to 5,000 ppm). Concentrations of CH4 declined with depth in all soils (to less than 1 ppm), but the rates of decrease with depth increased with elevation. In contrast, concentrations and depth trends of N2O varied erratically. Soils were net CO2 sources (0 to >1,500 kg CO2·ha−1·year−1), and net CH4 sinks (0.2 to >3 kg CH4·ha−1·year−1). The small and variable N2O fluxes were inconsistent with the trends in soil N δ15N values, which decreased by 5‰ to 6‰ over about 1,000 m of elevation. The high soil N δ15N values (up to nearly 17‰ at the lowest elevation) indicate that there is a soil N loss mechanism that is highly depleted in 15N, and gaseous losses—either NH3 or N2O/N2—are suspected of driving these values. In summary, there appears to be a strong climate control on both soil CO2 and CH4 concentrations and to a lesser degree on calculated fluxes. The soil N trace gas concentrations indicate that deserts can be either small sources or sinks of N2O and that there may be significant consumption of arid soil N2O.
Ions Accelerated by Sounder‐Plasma Interaction as Observed by Mars Express
Authors: Voshchepynets A. , Barabash S. , Ramstad R. , Holmstrom M. , Andrews D. , Nicolaou G. , Frahm R. A. , Kopf A. , Gurnett D. 
Published: November 2018

AbstractThe ion sensor of the Analyzer of Space Plasmas and Energetic Atoms (ASPERA‐3) experiment detects accelerated ions during pulses of radio emissions from the powerful topside sounder: the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) onboard Mars Express. Accelerated ions (O
, O+, and lighter ions) are observed in an energy range up to 800 eV when MARSIS transmits at a frequency close to the plasma frequency. Individual observations consist of almost monoenergetic ion beams aligned with the MARSIS antenna or lying in the plane perpendicular to the antenna. The observed ion beams are often accompanied by a small decrease in the electron flux observed by the electron sensor of Analyzer of Space Plasmas and Energetic Atoms 3. Observations indicate that the voltage applied to the antenna causes charging of the spacecraft to several hundreds of volts by the electrons of the ambient plasma. Positively charged ions are accelerated when the spacecraft discharges.
Space‐Based Constraints on Terrestrial Glyoxal Production
Authors: Silva Sam J. , Heald Colette L. , Li Meng 
Published: November 2018

AbstractGlyoxal is a volatile organic compound (VOC) in the atmosphere that is a precursor to ozone and secondary organic aerosol, can be a measure of photochemical activity, and is one of a small number of VOCs observable from space. However, the global budget of glyoxal is not well understood, and there has been limited exploration of whether current chemical transport models reproduce satellite observations of this VOC. In this work we take advantage of recent advances in the retrieval of glyoxal from the Ozone Monitoring Instrument along with retrieved formaldehyde and the GEOS‐Chem model to constrain global glyoxal sources. Model glyoxal is produced by direct emissions from fires (6.5 Tg/year) and secondary chemical production (32.9 Tg/year) from biogenic and anthropogenic precursors. The model reproduces the annual average terrestrial spatial variability in formaldehyde and glyoxal reasonably well, with an R2 of 0.8 and 0.5, respectively. We find that the model representation of biomass burning, C2H2, glyocolaldehyde, and isoprene‐dominated glyoxal production is consistent with the observations of glyoxal and formaldehyde, and the ratio of glyoxal to formaldehyde to within ~20%. However, the observations suggest that glyoxal production from the high monoterpene‐emitting boreal regions is underestimated in the model, with concentrations low by more than a factor of 3. This suggests that the oxidative chemistry of monoterpenes is not well represented in the GEOS‐Chem model and that more laboratory work is needed to constrain the impact of monoterpene emissions on atmospheric composition.
The Liquidus Temperature for Methanol‐Water Mixtures at High Pressure and Low Temperature, With Application to Titan
Authors: Dougherty A. J. , Bartholet Z. T. , Chumsky R. J. , Delano K. C. , Huang X. , Morris D. K. 
Published: November 2018

AbstractMethanol is a potentially important impurity in subsurface oceans on Titan and Enceladus. We report measurements of the freezing of methanol‐water samples at pressures up to 350 MPa using a volumetric cell with sapphire windows. For low concentrations of methanol, the liquidus temperature is typically a few degrees below the corresponding ice freezing point, while at high concentrations it follows the pure methanol trend. In the Ice‐III regime, we observe several long‐lived metastable states. The results suggest that methanol is a more effective antifreeze than previously estimated and might have played an important role in the development of Titan's subsurface ocean.
A New Sediment Accumulation Model of Cenozoic Depositional Ages From the Qaidam Basin, Tibetan Plateau
Authors: Cheng Feng , Garzione Carmala , Jolivet Marc , Guo Zhaojie , Zhang Daowei , Zhang Changhao 
Published: November 2018

AbstractTwo debated age models, with a basal age of ~50 Ma versus ~30 Ma, are proposed for the depositional age of Cenozoic strata within the Qaidam basin result in a diverse understanding of the initial pattern of deformation in the northern Tibetan Plateau. To evaluate these age models, we integrated isopach maps within the basin with published thermochronology data from surrounding ranges to balance the sediments preserved in the basin with materials eroded in the drainage area. When following the traditional ~50 Ma age model, the total volume of material eroded from the surrounding source area is 4.4 ± 0.3 × 105 km3. Using instead the ~30 Ma age model for the basal Lulehe Formation and related revisions to the basin chronology, the volume of eroded material is calculated at 3.5 ± 0.2 × 105 km3, which provides a better match to the calculated total volume of solid grains that are preserved in the basin (2.8 ± 0.1 × 105 km3). However, growth strata revealed in seismic profiles along the Southern Qaidam Thrust suggest reverse‐faulting began during the deposition of Oligocene‐Miocene strata. Following the ~50 Ma age model, the onset time of faulting along the Southern Qaidam Thrust is ~35.5 Ma, consistent with previous thermochronology results. If both age models are correct, then this requires a significant time‐transgressive nature to basin fill that allows for older ages of deposition in the southern part of the basin. This study highlights the need for further effort to determine the depositional age of the strata in the southern and western parts of the Qaidam basin.
Structural and Geochronological Constraints on the Early Mesozoic North Longmen Shan Thrust Belt: Foreland Fold‐Thrust Propagation of the SW Qinling Orogenic Belt, Northeastern Tibetan Plateau
Authors: Yan Dan‐Ping , Qiu Liang , Wells Michael L. , Zhou Mei‐Fu , Meng Xiangkun , Lu Song , Zhang Sen , Wang Yu , Li Shu‐Bing 
Published: November 2018

AbstractThe NE striking Longmen Shan Thrust Belt (LSTB) forms the northeastern margin of Tibetan Plateau and merges northward with the southwestern Qinling orogenic belt. The LSTB is characterized by the Late Cenozoic SE‐ward overthrusting and a current 60‐ to 70‐km crustal thickness. Structural constraints link the Late Cenozoic deformation and crustal thickening of the LSTB to the formation of the Tibetan plateau. However, although older Mesozoic deformations are widely identified, including Triassic shortening, they remain underappreciated in the development of the LSTB as the Cenozoic history has been the recent research focus. Thus, it is important to document the early Mesozoic tectonics of the LSTB to better understand the Cenozoic orogeny along the northeastern margin of the Tibetan plateau. Here we synthesize existing and new mapping, structural analyses and geochronology of three regions of the northern LSTB: the Bikou, Tangwangzhai, and Longwangmiao regions. Our observations suggest that the Bikou, Tangwangzhai, and Longwangmiao thrust complexes have similar kinematic styles of southward foreland fold‐and‐thrust propagation. New 40Ar/39Ar dating results show that these thrust complexes have deformational ages at circa 237 Ma to circa 180 Ma, respectively, and diachronously emplaced before 201–174 Ma. Triassic shortening structures involving metamorphic rocks are unconformably overlain by Lower to Middle Jurassic strata. We propose a new kinematic model in which Middle to Late Triassic, top‐to‐the south, in‐sequence imbricate thrusts developed in the northern and central LSTB, suggesting that the LSTB was initially built in the early Mesozoic by the southward propagation of the foreland belt of the SW Qinling orogenic belt.