bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tree invasion in secondary grasslands diminishes herbaceous biomass and diversity: A study of mechanisms behind the process
Authors: Ferraina Antonella , Molina Cecilia D. , Mazía Noemí , Piñeiro Gervasio , Miranda Isabel , Chaneton Enrique José 
Published: September 2021

AbstractQuestionsHow is plant biomass, composition and diversity in secondary grasslands affected by tree invasion? How do light conditions generated by invasive trees and soil legacy affect grassland's structure and functioning? Which mechanism is more important?LocationInland Pampa, Buenos Aires, Argentina.MethodsWe established a long‐term manipulative reciprocal transplant experiment by transplanting soil monoliths coming from two origins: grasslands (G) and invaded woody patches (W) into three different habitats: open grasslands (OG), woody patches (WP), and artificially shaded grasslands (SG).ResultsSeven years after the beginning of the experiment, litter, above‐ and below‐ground herbaceous biomass decreased from OG to WP habitats, with SG habitats showing intermediate values. However, differences between OG and WP habitats disappeared when tree (coarse) roots, and tree litter biomass were considered. No significant differences between the origin of the soil monoliths (G or W) were detected (p > 0.10), except for herbaceous roots biomass that, contrary to expectations, was higher in all habitats when the transplanted soil monoliths came from a W origin. Additionally, biomass of C3 grasses was higher in WP habitats and biomass of C4 grasses was higher in OG habitats, while biomass of forbs had the highest biomass in SG habitats. The inverse Simpson's index decreased from OG (2.08), through SG (1.73) to WP habitats (1.14), suggesting higher dominance in WP.ConclusionsOur study helps to glimpse the main mechanism driving community changes after tree invasions in temperate grassland communities. We demonstrated that light reduction beneath the tree canopies has a more important role than soil legacy in determining structure and functioning of grasslands, even though invasion of Gleditsia triacanthos also affected soil properties such as water content and organic carbon.
Canopy and understorey tree guilds respond differently to the environment in an Indian rain forest
Authors: Schmitt Sylvain , Raevel Valérie , Réjou‐Méchain Maxime , Ayyappan Narayanan , Balachandran Natesan , Barathan Narayanan , Rajashekar Gopalakrishnan , Munoz François 
Published: September 2021

AbstractQuestionsChanges in the functional composition of tree communities along resource availability gradients have received attention, but it is unclear whether understorey and canopy guilds respond similarly to different light, biomechanical, and hydraulic constraints.LocationAn anthropically undisturbed, old‐growth wet evergreen dipterocarp forest plot located in Karnataka State, India.MethodsWe measured leaf and wood traits of 89 tree species representing 99% of all individuals in a 10‐ha permanent plot with varying topographic and canopy conditions inferred from Light Detection And Ranging (LiDAR) data. We assigned tree species to guilds of canopy and understorey species and assessed the variation of the guild‐weighted means of functional‐trait values with canopy height and topography.ResultsThe functional‐trait space did not differ between canopy and understorey tree species. However, environmental filtering led to significantly different functional composition of canopy and understorey guild assemblages. Furthermore, they responded differently along environmental gradients related to water, nutrients, light, and wind exposure. For example, the canopy guild responded to wind exposure while the understorey guild did not.ConclusionsThe pools of understorey and canopy species are functionally similar. However, fine‐scale environmental heterogeneity impacts differently on these two guilds, generating striking differences in functional composition between understorey and canopy guild assemblages. Accounting for vertical guilds improves our understanding of forest communities’ assembly processes.
Asymmetric input contracts under price leadership
Authors: Escrihuela‐Villar Marc , Ferrarese Walter 
Published: September 2021

AbstractThis paper considers a vertically related industry where an upstream supplier simultaneously and independently negotiates linear tariffs with two asymmetrically capacity constrained downstream retailers endowed with (possibly) asymmetric bargaining powers over the purchase of an input. We introduce price leadership as the type of downstream competition. An increase in the upstream supplier’s bargaining power toward the large firm induces a positive externality on the small firm’s tariff. We also obtain that, a priori the small firm may end up (i) demanding a larger stock of the input and (ii) paying less for it. Our model also proves useful to show that the well‐known countervailing buyer power hypothesis could not hold because an integrated downstream firm might negotiate a better input price without any pass‐through to the final consumers. We mainly relate our analysis to the UK grocery market and to the recent empirical evidence regarding its functioning.
Prolonged mechanical ventilation increases diaphragm arteriole circumferential stretch without changes in stress/stretch: Implications for the pathogenesis of ventilator‐induced diaphragm dysfunction
Authors: Horn Andrew G. , Kunkel Olivia N. , Baumfalk Dryden R. , Simon Mikaela E. , Schulze Kiana M. , Hsu Wei‐Wen , Muller‐Delp Judy , Poole David C. , Behnke Bradley J. 
Published: September 2021

AbstractIntroductionProlonged mechanical ventilation (MV; ≥6 h) results in large, time‐dependent reductions in diaphragmatic blood flow and shear stress. We tested the hypothesis that MV would impair the structural and material properties (ie, increased stress/stretch relation and/or circumferential stretch) of first‐order arterioles (1A) from the medial costal diaphragm.MethodsShear stress was estimated from isolated arterioles and prior blood flow data from the diaphragm during spontaneous breathing (SB) and prolonged MV (6 h MV). Thereafter, female Sprague‐Dawley rats (~5 months) were randomly divided into two groups, SB (n = 6) and 6 h MV (n = 6). Following SB and 6 h MV, 1A medial costal diaphragm arterioles were isolated, cannulated, and subjected to stepwise (0–140 cmH2O) increases in intraluminal pressure in calcium‐free Ringer's solution. Inner diameter and wall thickness were measured at each pressure step and used to calculate wall:lumen ratio, Cauchy‐stress, and circumferential stretch.ResultsCompared to SB, there was a ~90% reduction in arteriolar shear stress with prolonged MV (9 ± 2 vs 78 ± 20 dynes/cm2; p ≤ .05). In the unloaded condition (0 cmH2O), the arteriolar intraluminal diameter was reduced (37 ± 8 vs 79 ± 13 μm) and wall:lumen ratio was increased (120 ± 18 vs 46 ± 10%) compared to SB (p ≤ .05). There were no differences in the passive diameter responses or the circumferential stress/stretch relationship between groups (p > .05), but at each pressure step, circumferential stretch was increased with 6 h MV vs SB (p ≤ .05).ConclusionDuring prolonged MV, medial costal diaphragm arteriolar shear stress is severely diminished. Despite no change in the material behavior (stress/stretch), prolonged MV resulted in altered structural and mechanical properties (ie, elevated circumferential stretch) of medial costal diaphragm arterioles. This provides important novel mechanistic insights into the impaired diaphragm blood flow capacity and vascular dysfunction following prolonged MV.
Comparative efficacy of the bone‐anchored maxillary protraction protocols for orthopaedic treatment in skeletal Class III malocclusion: A Bayesian network meta‐analysis
Authors: Hu Shoushan , An Ke , Peng Yiran 
Published: September 2021

AbstractObjectiveTo compare the treatment effects of five bone‐anchored maxillary protraction protocols (BAC3E, BAMP, BARME‐FM, BARME‐ME, SAFM) for skeletal Class III malocclusion.MethodsWe conducted a systematic literature search through CENTRAL, EBSCO, PubMed and Web of Science and included the randomized controlled trials and clinical controlled trials, which met the criteria. A Bayesian network meta‐analysis (NMA) for SNA, SNB, ANB, SN‐MP and Wits appraisal was performed in R software using a random consistency model. The additional analyses included node‐splitting analysis, statistical heterogeneity analysis, sensitivity analysis and ranking probability by SUCRA.ResultsA total of 598 articles were initially obtained; 13 articles involving 482 individuals were eventually included. Among the five bone‐anchored maxillary protraction protocols, the largest increment in SNA and Wits appraisal was observed in the BAMP group and BAC3E group, respectively; the SAFM, BAC3E and BAMP groups showed similar capability in terms of changes of ANB; least clockwise rotation of the mandible was found in the BARME‐ME group, followed by the BAMP group; dental compensation appears to be most pronounced in the BAC3E group; and intermaxillary traction seems to reduce the lingual inclination of lower incisors and even cause labial inclination.ConclusionsThe SAFM, BAMP and BAC3E groups seem to be advantageous in the improvement of the maxillo‐mandibular relationship, followed by the BARME‐FM and BARME‐ME groups. The findings of this study should be interpreted with caution as only short‐term effects were compared and the quality of evidence ranged from very low to moderate. More RCTs with high‐quality and long‐term investigation are needed.
Fiscal easing in local governments facing potential merger: Visible in budgets or hidden in overruns?
Authors: Askim Jostein , Houlberg Kurt , Klausen Jan Erling 
Published: September 2021

AbstractMergers incentivize local governments to ease their fiscal policies before the merger is implemented. This incentive is powerful: it is known that local governments start easing fiscal policies even before they know for sure that a merger will occur and even if merging is what they want. Based on a study of Norwegian municipalities, this article shows that irrespective of whether local governments face certain or potential mergers, their fiscal easing is manifested primarily in budget overruns rather than candidly documented in budgets. Among local governments facing a potential merger, unwilling governments ease their fiscal policies more than willing ones do and to a larger extent apply a concealment strategy.
Measuring the impact of clinical practice guidelines on infantile hemangioma referrals
Authors: Barton Michael T. , Latour Emile , Small Alison , Leitenberger Sabra , Funk Tracy 
Published: September 2021

AbstractHigh‐risk infantile hemangiomas may be associated with significant patient comorbidity. The American Academy of Pediatrics published clinical practice guidelines with recommendations to refer high‐risk hemangiomas early. The results of this study suggest that these guidelines may have resulted in an earlier referral age of patients with high‐risk IH to hemangioma specialists.
Constraints on the preservation of proxy data in carbonate archives – lessons from a marine limestone to marble transect, Latemar, Italy
Authors: Mueller Mathias , Jacquemyn Carl , Walter Benjamin F. , Pederson Chelsea L. , Schurr Simon L. , Igbokwe Onyedika A. , Jöns Niels , Riechelmann Sylvia , Dietzel Martin , Strauss Harald , Immenhauser Adrian 
Published: September 2021

AbstractThis work evaluates an exceptionally complex natural laboratory, the Middle Triassic Latemar isolated platform in the northern Italian Dolomite Mountains and explores spatial and temporal gradients in processes and products related to contact metamorphism, dolomitization and dedolomitization of marine limestones. The relation between petrographic change and re‐equilibration of geochemical proxy data is evaluated from the perspective of carbonate‐archive research. Hydrothermal dolomitization of the limestone units is triggered by dykes and associated hydrothermal fluids radiating from the nearby Predazzo Intrusion. Detailed petrography, fluid inclusion analysis, δ13C and δ18O data and 87Sr/86Sr isotope ratios shed light on the extreme textural and geochemical complexity. Metamorphic and diagenetic patterns include: (i) peak‐metamorphic and retrograde‐metamorphic phases including three dolomite marbles, two dedolomite marbles, brucite, magnesium silicates and late‐stage meteoric/vadose cement at the contact aureole; (ii) four spatially defined episodes of dolomitization, authigenic quartz, low magnesium calcite and late‐stage meteoric cement at the Latemar isolated platform; and (iii) kilometre‐scale gradients in δ13C values from the contact aureole towards the platform interior. Results shown here are relevant for two reasons: first, the spatial analysis of alteration products ranging from high‐grade metamorphic overprint of marbles at temperatures of 700°C in the contact aureole to moderately altered limestones in the platform interior at temperatures <100°C, allows the observation of processes that commonly occur along vertical (prograde) gradients from shallow burial to metamorphism at depths >20 km. Second, under rock‐buffered conditions, and irrespective of metamorphic to diagenetic fluid−rock interactions, both marbles, and low‐temperature hydrothermal dolomites have conservative marine δ13C and δ18O values. The fact that metamorphism and hydrothermal dolomitization of precursor limestones and early diagenetic dolostones did not per se reset environmental proxy data is of interest for those concerned with carbonate archive research in Earth’s deep time.
Hospital transfusion service operations during the SARS‐CoV‐2 pandemic: Lessons learned from the AABB hospital survey in preparation for the next infectious disease outbreak
Authors: Rajbhandary Srijana , Shmookler Aaron , Cohn Claudia S. , Nunes Eduardo , Karafin Matthew S. , Stubbs James , Pagano Monica B. 
Published: September 2021

AbstractBackgroundThe SARS‐CoV‐2 pandemic disrupted hospital operations, affected the blood supply, and challenged the health care system to develop new therapeutic options, including convalescent plasma (CCP). The aim of this study is to describe and analyze blood supply fluctuations and the use of convalescent plasma in 2020.MethodsAABB distributed a weekly and biweekly questionnaire through email to hospital‐based members (HBM).ResultsThe survey was sent to 887 HBM with 479 unique respondents, most of the hospitals served pediatric and adult patients, and all states of the country participated, except Idaho and Vermont. Fifty four percent of HBM reported increased wastage in the early phase of the pandemic (May), which decreased to 4% by the end of June and throughout the rest of the year. The majority of HBM reported receiving alerts from their blood suppliers reporting blood shortages throughout the year. During March and April, only 12% of HBM were performing elective surgical procedures. The top reasons to delay procedures were: bed availability (28%); COVID‐19 caseload (23%; and blood availability (19%). By mid‐April, 42% HBM had transfused CCP and reported >24 h delay in getting the units; the vast majority obtained CCP using the Expanded Access Protocol, and later, the Emergency Use Authorization. HBM consistently prioritized the most severe patients to receive CCP, but the proportion of severely ill recipients fell from 52% to 37% between May and October, with an increase from 5% to 21% of HBM providing CCP transfusion early in the course of the disease.DiscussionBlood utilization and availability fluctuated during the pandemic. The fluctuations appeared to be related to the number of COVID‐19 in the community. The use and regulatory landscape of CCP rapidly evolved over the first 8 months of the pandemic.
The effects of pulmonary hypertension on skeletal muscle oxygen pressures in contracting rat spinotrapezius muscle
Authors: Schulze Kiana M. , Weber Ramona E. , Colburn Trenton D. , Horn Andrew G. , Ade Carl J. , Hsu Wei‐Wen , Poole David C. , Musch Timothy I. 
Published: September 2021

New Findings

What is the central question of this study?
Does impairment in the dynamics of O2 transport in skeletal muscle during a series of contractions constitute a potential mechanism underlying reduced exercise capacity in pulmonary hypertension?

What is the main finding and its importance?
Pulmonary hypertension compromises the dynamic matching of skeletal muscle O2 delivery‐to‐utilization following contraction onset in the rat spinotrapezius muscle. These results implicate a role for vascular dysfunction in the slow kinetics and exercise intolerance present in pulmonary hypertension.

AbstractPulmonary hypertension (PH) is characterized by pulmonary vascular dysfunction and exercise intolerance due, in part, to compromised pulmonary and cardiac function. We tested the hypothesis that there are peripheral (i.e., skeletal muscle) aberrations in O2 delivery ()‐to‐O2 utilization () matching and vascular control that might help to explain poor exercise tolerance in PH. Furthermore, we investigated the peripheral effects of nitric oxide (NO) in attenuating these decrements. Male Sprague–Dawley rats (n = 21) were administered monocrotaline (MCT; 50 mg/kg, i.p.) to induce PH. Disease progression was monitored via echocardiography. Phosphorescence quenching determined the O2 partial pressure in the interstitial space () in the spinotrapezius muscle at rest and during contractions under control (SNP−) and NO‐donor (sodium nitroprusside, SNP+) conditions. MCT rats displayed right ventricular (RV) hypertrophy (right ventricle/(left ventricle + septum): 0.44 (0.13) vs. 0.28 (0.05)), pulmonary congestion, increased RV systolic pressure (48 (18) vs. 20 (8) mmHg) and arterial hypoxaemia (: 64 (9) vs. 82 (9) mmHg) compared to healthy controls (HC) (P < 0.05). was significantly lower in MCT rats during the first 30 s of SNP− contractions. SNP superfusion elevated in both groups; however, MCT rats demonstrated a lower throughout SNP+ contractions versus HC (P < 0.05). Thus, for small muscle mass exercise in MCT rats, muscle oxygenation is impaired across the rest‐to‐contractions transition and exogenous NO does not raise the ‐to‐ ratio in contracting muscle to the same levels as HC. These data support muscle ‐to‐ mismatch as a potential contributor to slow kinetics and therefore exercise intolerance in PH and suggest peripheral vascular dysfunction or remodelling as a possible mechanism.
Design of Low-Cost Endoscope Based on Novel Wire-Driven Rotary Valve and Water-Jet Mechanism
Authors: Ma Guoyu , Zuo Siyang , Liu Jianbin 
Published: September 2021

Abstract
To improve the prevalence of screening for gastric cancer in low-income areas, a low-cost endoscope based on a novel wire-driven rotary valve and water-jet mechanism is proposed. The primary component of this endoscope is a rotary valve whose core is driven by a stepper motor through a flexible wire, which controls the direction of the water jet. This enables it to reach any point in the workspace by controlling the valve core angle and water-jet intensity. The envelope surface of the endoscope tip trajectory is likely a hemisphere. The horizontal diameter of the working space projection is approximately 350 mm, which is sufficient to observe most parts of the greater curvature of the stomach. The image-acquisition performance of the designed endoscope was satisfactory in a phantom experiment. The introduction of the novel rotary valve greatly simplifies the structure and reduces the cost of the proposed endoscope. With low cost and high portability, this endoscope provides a good alternative for early gastric cancer screening in low- and middle-income areas.
Best Practices for Meta-Reviews in Physical Activity and Health Research: Insights From the Physical Activity Guidelines for Americans Advisory Committee Scientific Report
Authors: Pescatello Linda S. , Hennessy Emily A. , Katzmarzyk Peter T. , Kraus William E. , Fish Anne F. , Craft Lynette L. , Johnson Blair T. 
Published: September 2021

Background: Systematic reviews (SRs) and meta-analyses (MAs) have proliferated with a concomitant increase in reviews of SRs/MAs or “meta-reviews” (MRs). As uncovered by the 2018 US Physical Activity Guidelines Advisory Committee (PAGAC), there is a paucity of best practice guidance on MRs on physical activity health-related research. This manuscript aims to fill this gap. Methods: In total, the PAGAC conducted 38 literature searches across 3 electronic databases and triaged 20,838 titles, 4913 abstracts, and 2139 full texts from which 1130 articles qualified for the PAGAC Scientific Report. Results: During the MR process, the following challenges were encountered: (1) if the SR/MA authors had limited experience in synthesis methodology, they likely did not account for risk of bias in the conclusions they reached; (2) many SRs/MAs reviewed the same primary-level studies; (3) many SRs/MAs failed to disclose effect modifier analyses; (4) source populations varied; (5) physical activity exposures were nonstandardized; and (6) dose–response effects or effect modification of the physical activity exposure could not be identified. Conclusions: Using examples from the PAGAC Scientific Report, we provide (1) a high-level introduction to MRs; (2) recommended steps in conducting a MR; (3) challenges that can be encountered; and (4) guidance in addressing these challenges.
Geochemical indicators of a biogenic component in source materials of moldavites
Authors: Mizera Jiří , Řanda Zdeněk 
Published: September 2021

ABSTRACT
Formation of the Central European tektites, known as moldavites, has been associated with a large meteorite impact in southern Germany 14.8 m.y. ago. The geochemical link between moldavites and their source materials, and the processes of their possible chemical differentiation still remain uncertain. Some differences in chemical composition between moldavites and sediments of corresponding age from the surroundings of the Ries crater could be explained by a hypothesis according to which biomass covering the pre-impact area contributed to the source materials. In a comparison of the geochemical compositions of a large representative set of moldavites and suitable Ries sediments, enrichment in elements K, Ca, Mg, and Mn and depletion of Na in moldavites, similar to redistribution of these elements during their transfer from soil to plants, could indicate the unconventional biogenic component in moldavite source materials. Simple mixing calculations of the most suitable Ries sediments and a model biogenic component represented by burned biomass residue are presented. The plausibility of the estimated biomass contribution considering reconstructions of the middle Miocene paleoenvironment in the pre-impact Ries area is discussed. No significant vapor fractionation is required to explain the observed variability of moldavite chemical composition.