bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of dimethylformamide to cryopreserve alpaca semen previously incubated with collagenase
Authors: Flores Huarco Nils H. , Giuliano Susana M. , Fumuso Fernanda G. , Miragaya Marcelo H. , Cucho Dolmos Hernán C. , Carretero María I. 
Published: August 2021

AbstractThe objective of this study was to evaluate the effect of collagenase and two final dimethylformamide (DMF) concentrations (4% and 7%) on alpaca frozen‐thawed sperm quality. A total of 25 ejaculates from 5 alpaca were obtained using electroejaculation. Each individual ejaculate was evaluated and then diluted 4:1 in a solution of 1 mg/ml collagenase in HEPES‐TALP medium and incubated for 4 min at 37°C. Subsequently, samples were diluted in TRIS‐fructose‐citric acid‐egg yolk and cooled to 5°C. Then, each sample was divided in two aliquots and DMF at final concentration of 4% or 7% was added, equilibrated for 1 hr at 5°C and frozen over liquid nitrogen vapours. A Kruskal–Wallis test was used to evaluate the sperm morphometry, and Completely Random Block designs were used to analyse sperm motility, viability, membrane function and acrosome status. After collagenase incubation, none of the samples showed thread formation, and sperm parameters were preserved. Non‐progressive motile sperm were higher (p < .05) in equilibrated samples (4% DMF: 31.8 ± 8.3% and 7% DMF: 36.3 ± 11.8%) compared to raw (10.1 ± 4.3%) and frozen‐thawed semen (4% DMF: 9.7 ± 1.8% and 7% DMF: 7.5 ± 3.2%). Sperm membrane function, membrane integrity and intact acrosomes were higher (p < .05) in raw semen (40.1 ± 12.2%, 94.6 ± 3.2% and 91.3 ± 8.1%) compared to frozen‐thawed samples (4% DMF: 19.8 ± 4.7%, 53.2 ± 2.7%, 65.7 ± 8.7% and 7% DMF: 20.4 ± 4.5%, 54.1 ± 1.4%, 64.6 ± 9.1%). Length of the sperm head was lower in frozen‐thawed samples, being statistically different with 4% DMF compared to pre‐freezing samples. The ratio between acrosome and head areas was greater (p < .05) in frozen‐thawed samples. Incubation of raw alpaca semen with collagenase decreased the thread formation without affecting sperm quality. Frozen of collagenase treated alpaca semen with 4% or 7% DMF did not preserve the sperm parameters in thawed samples.
Measuring and framing support for universal basic income
Authors: Jordan Soren , Ferguson Grant , Haglin Kathryn 
Published: August 2021

AbstractWe execute an original survey experiment to examine the extent and determinants of support for a nascent policy issue, universal basic income (UBI), in the American public. We explore the effects of how UBI is framed (either in the context of values or the context of policy), finding three key results. First, UBI is primarily a Democratic and liberal policy. Second, negative arguments against UBI move support for UBI more than positive arguments. Third, and surprisingly, respondents are equally affected by both policy‐driven and value‐driven arguments about UBI. In conclusion, an increase in messaging about UBI is likely to widen existing partisan differences in UBI support. These differences are unlikely to be won over by policy or values arguments.
Direct and indirect influences of political regimes on corruption
Authors: Goel Rajeev K. , Nelson Michael A. 
Published: August 2021

AbstractObjectiveThis paper studies the direct and indirect impacts of political regimes on corruption. Whereas the interplay of government is fundamental to corrupt acts, the present research sheds new light by showing the direct and indirect influences of dimensions of government structure on corruption.MethodsWe employ two different estimation techniques. First, we use OLS regressions, with year and regional dummies. Second, we employ mediation analysis to account for the intermediate role of government size in the relation between government structure and corruption in order to gauge the direct and indirect influences on corruptionResultsResults show that government structure, across various dimensions of authoritarian and nonauthoritarian regimes, significantly impacted cross‐national corruption. In particular, a nation's stock of democracy and parliamentary systems lowered corruption, while executive tenure and dimensions of authoritarianism added to corruption. On the other hand, the size of the legislature did not matter when it came to corruption. However, the direct influences of these government structure variables are mitigated or reinforced when the intermediate role of government size is considered in a mediation analysis.ConclusionsThe breakdown into the direct and indirect effects on corruption is a novel insight of this work, with useful policy implications.
Implementation has failed, implementation studies have failed even more: Racism and the future of systemic change
Authors: Tormos‐Aponte Fernando , Wright James E. , Brown Heath 
Published: August 2021

AbstractObjectiveThis article identifies the role of structural racism in policy implementation and argues that a starting point to evaluate the potential outcomes of calls for systemic change is to better situate racism in the study of policy implementation.MethodThis article reviews existing policy implementation literature to assess the extent to which they account for structural racism in their analyses of policy implementation success and failure.ResultPolicy failures have been attributed to multiple factors, including hierarchies and communication problems, but rarely to racism.ConclusionIf racism is to be taken seriously by public administration scholars, then a new conceptual understanding is called for along with better efforts to operationalize the crippling impact racism has on public organizations.
State‐level immigration legislation and social life: The impact of the “show me your papers” laws
Authors: Maggio Christopher 
Published: August 2021

AbstractObjectiveFrom 2010 to 2011, several states passed legislation aimed at identifying and deporting undocumented immigrants. Despite partial or full enjoinment at various times, there are reasons to believe that the passage of these laws could have had a negative impact on social life for immigrants and Hispanics. This study attempts to quantify the impact of these restrictive laws on time spent socializing, as reported in the American Time Use Survey.MethodThis study uses a natural experiment and difference in differences design.ResultsI find that Hispanics in states that passed these laws spent less time socializing after their passage, though only in counties with relatively low Hispanic populations around the time of passage.ConclusionOverall, this study provides evidence of a negative impact of extreme immigration policy on social life in the Hispanic community.
Comparison of digital elevation models through the analysis of geomorphic surface remnants in the Desatoya Mountains, Nevada
Authors: Dobre Bernadett , Kovács István P. , Bugya Titusz 
Published: August 2021

AbstractThis article explores the advantages and limitations of open‐source digital elevation models (DEMs) generated from various acquisition methods and at various spatial resolutions, through extracting geomorphic surface remnants in a semi‐arid, mountainous topographic environment. Even if the tested models have well‐known vertical accuracy and precision, their reliability for peak detection is still waiting to be studied. In this research, we investigate peaks as remnants of degraded geomorphic surfaces. Peaks of surface remnants can help to reconstruct geomorphic surfaces and evaluate DEM applicabilities, since they can enhance the identification of overall accuracy. Our methodology uses a well‐known open‐source GRASS GIS Geomorphons module (r.geomorphon) on several recently released and widely used DEMs covering the Desatoya Mountains study area. We conclude that, despite the characteristic differences in the accuracy of the analyzed DEMs, all of those examined proved to be appropriate to detect surface remnants.
The establishment and spread of the stem‐boring weevil Listronotus setosipennis (Coleoptera: Curculionidae) released against the invasive weed Parthenium hysterophorus L. (Asteraceae) in Ethiopia
Authors: Mersie Wondi , Amare Tesfay , Chala Lidya Alemayehu , Negeri Mulugeta , McNamee Clyde 
Published: August 2021

AbstractThe establishment and spread of the stem‐boring weevil, Listronotus setosipennis (Coleoptera: Curculionidae) released in 2017 for the control of the invasive weed, Parthenium hysterophorus (L.) (Asteraceae) at four locations in northeastern Ethiopia were assessed over a 4‐year period. The number of L. setosipennis eggs on parthenium in 0.5 m × 0.5 m quadrats was recorded at each location where the weevil was originally released and where it spread later. The weevil damage to parthenium and the distance it spread were also recorded. At all release locations, the number of L. setosipennis eggs detected increased over the 4‐year assessment period indicating the build‐up of the weevil population where it was released. At one of these locations, Chorisa, the number of eggs increased from 2.7 ± 1.3 m−2 in 2017 to 92 ± 6.1 m−2 in 2020. Similarly, at the site where the weevil spread (dispersal site), the number of L. setosipennis eggs detected on parthenium rose over the 4‐year period. L. setosipennis larvae damage to parthenium was evident at all release locations ranging from 13.3 ± 3.3% to 36.7 ± 6.7%. Similar level of damage (36.7 ± 5% to 66.7 ± 8.3%) was also recorded at the dispersal sites. After 4 years, the maximum distance L. setosipennis spread from its original release spots was 185.3 ± 12.0 m. The establishment and spread of the weevil were slow but was steady at all locations in northeastern Ethiopia.
A new approach to quantify weed suppression, crop tolerance and weed‐free yield in cereal variety trials without weed‐free plots
Authors: Rasmussen Jesper , Jensen Signe M. , Mariegaard Pedersen Tove 
Published: August 2021

AbstractCereal varieties are commonly tested in the presence of weeds in organic agriculture, and a variety of test programmes with weeds are relevant in relation to fields containing herbicide‐resistant weeds. However, the interpretation of results from variety trials with weeds is complex because different levels of weed pressure affect the yield differently. Crop yield is a result of the combined effect of weed suppression, crop tolerance and the weed‐free yield. Until now, there has been no attempt to separate weed suppression, crop tolerance and weed‐free yield in ordinary variety trials without weed‐free plots. This study applied a new approach based on the combination of functional trait analysis and analysis of variance (ANOVA). A total of 16 variety trials were analysed with early crop coverage, final canopy height and disease severity as functional traits. The main objectives were to quantify weed suppression, crop tolerance and weed‐free yield in spring barley varieties, and to evaluate the importance of the trade‐off between weed suppression and weed‐free yield. Results showed that early crop coverage and final canopy height both increased weed suppression, and taller cultivars tolerated weeds better than shorter cultivars. However, a trade‐off between canopy height and weed‐free yield made it difficult to justify the selection of tall varieties unless the weed pressure was at its maximum level in the trials. Large early crop coverage was an advantage in terms of weed suppression and weed‐free yield, making early coverage a better selection criterion than final canopy height under the condition that early coverage is a result of genotypic variation. Future studies have to show how well genotypic and phenotypic variations are related in terms of early coverage and final canopy height.
Longitudinal environmental Staphylococcus contamination in a new small animal veterinary hospital and utility of cleaning checklists
Authors: Hunter Noelle D. , Hoet Armando E. , van Balen Joany , Stull Jason W. 
Published: August 2021

AbstractStaphylococci are inhabitants of skin and mucous membranes with Staphylococcus pseudintermedius (SP) and Staphylococcus aureus (SA) serving as important pathogens for animals and people, respectively. Previous research has identified the environment as potentially important in hospital‐associated infections and zoonotic transmission in veterinary settings. The objective of this pilot study was to determine the longitudinal prevalence over repeated samplings of environmental coagulase‐positive Staphylococcus (CPS) in a new veterinary hospital and evaluate associations between contamination and environmental and clinical (caseload, cleaning checklists and staff numbers) factors. Cleaning and disinfection compliance, based on staff‐completed checklists, were reviewed for the three shifts immediately prior to sampling. We hypothesized that over time, environmental contamination would increase as the clinic developed and caseload increased and compliance to cleaning checklists would decrease with increasing caseload. Over 18 months, 351 environmental samples were collected at five sampling times (sampling occurred before opening the hospital and every 3 to 6 months thereafter). Overall contamination with CPS was 30.8% (108/351), with SA (16.8%) and SP (13.1%) identified from the contaminated surfaces. Overall, methicillin‐resistant strains (MRSA and MRSP) were infrequently recovered (combined n = 3; <1%). Point prevalence of CPS contamination was relatively stable over the study period (22.5%–28.4%), with the exception of an increase at the fourth sampling (52.9%). Cleaning compliance varied over the study period (57.9%–100%); the lowest reported cleaning coincided with the highest proportion of CPS contamination. The most commonly contaminated surfaces were chairs (7/15; 46.7%), examination tables (19/47; 40.4%) and computers (12/35; 34.3%); these items were infrequently included on cleaning lists. Surfaces not included in the checklist were 2.3 times more likely to be contaminated by CPS than those that were included (OR: 2.3, CI 95%: 1.02 –5.35, p‐value=.04). MRSA and MRSP were rarely isolated from the environment in the newly opened hospital, indicating it may take time for resistant strains to enter the environment and persist on surfaces. This study identified the possible utility of cleaning checklists for directing cleaning practices and reducing the environmental contamination.
A Study on Fundamental Combustion Properties of Oxymethylene Ether-2
Authors: Ngugi John M. , Richter Sandra , Braun-Unkhoff Marina , Naumann Clemens , Köhler Markus , Riedel Uwe 
Published: August 2021

Abstract
Oxymethylene ethers (OMEn, n = 1–5) are a promising class of synthetic fuels that have the potential to be used as additives or substitutes to diesel in compression ignition engines. A comprehensive understanding of their combustion properties is required for their safe and efficient utilization. In this study, the results of a combined experimental and modeling work on oxidation of OME2 are reported: (i) Ignition delay time measurements of stoichiometric OME2/synthetic air mixtures diluted 1:5 with nitrogen using the shock tube method at pressures of 1, 4, and 16 bar, and (ii) laminar flame speeds of OME2/air mixtures using the cone angle method at atmospheric and elevated pressures of 3 and 6 bar. The experimental data sets obtained have been used for validation of three detailed reaction mechanisms of OME2 obtained from literature. The results of ignition delay time measurements showed that ignition of OME2 is characterized by pre-ignition activity at the low temperature side of the measurements regardless of the pressure. Regarding the performance of the different reaction mechanisms, the model from Cai et al. (2020, “Auto-Ignition of Oxymethylene Ethers (OMEn, n = 2–4) as Promising Synthetic e-Fuels From Renewable Electricity: Shock Tube Experiments and Automatic Mechanism Generation,” Fuel, 264, p. 116711) best predicted the temperature and pressure dependence of ignition delay times. For laminar flame speeds, the experimental data were well matched by the mechanism from Ren et al. (2019) at p = 1, 3, and 6 bar and for all equivalence ratios considered. From sensitivity analyses calculations, it was observed that chain reactions involving small radicals, i.e., H, O, OH, HO2, and CH3 control the oxidation of OME2. The comparison of the results of this work and our previous work (Ngugi et al. (2021)) on OME1 show that these two fuels have similar oxidation pathways. The results obtained in this work will contribute to a better understanding of the combustion of oxymethylene ethers, and thus, to the design and optimization of burners and engines as well.
Accurate Inlet Boundary Conditions to Capture Combustion Chamber and Turbine Coupling With Large-Eddy Simulation
Authors: Martin Benjamin , Duchaine Florent , Gicquel Laurent , Odier Nicolas , Dombard Jérôme 
Published: August 2021

Abstract
The coupling between different components of a turbomachinery is becoming more widely studied especially by use of computational fluid dynamics. Such simulations are of particular interest especially at the interface between a combustion chamber and a turbine, for which the prediction of the migration of hotspots generated in the chamber is of paramount importance for performance and life-duration issues. Despite this need for fully integrated simulations, typical turbomachinery simulations however often only consider isolated components with either time-averaged constant value, radial profile or least frequently two-dimensional maps imposed at their inlet boundaries preventing any accurate two-way coupling. The objective of this study is to investigate available solutions to perform isolated simulations while taking into account the effect of multicomponent coupling. Investigations presented in the paper focus on the full aero-thermal combustor-turbine interaction research (FACTOR) configuration. The first step of the proposed method is to record conservative variables solved by the large-eddy simulation (LES) code at the interface plane between the chamber and the turbine of a reference simulation. Then, using the spectral proper orthogonal decomposition (SPOD) method, the recorded data is analyzed and can be partially reconstructed using different numbers of frequencies. Using the partial reconstructions, it is then possible to replicate a realistic inlet boundary condition for isolated turbine simulations with both velocity and temperature fluctuations, while reducing the storage cost compared to the initial database. The integrated simulation is then compared to the isolated simulations as well as against simulations making use of averaged quantities with or without synthetic turbulence injection at their inlet. The isolated simulations for which the inlet condition is reconstructed with a large number of frequencies show very good agreement with the fully integrated simulation compared to the typical isolated simulation using average quantities at the inlet. As expected, decreasing the number of frequencies in the reconstructed signal deteriorates the accuracy of the resulting signal compared to the full recorded database. However, isolated simulations with a low number of frequencies still perform better than standard boundary conditions, especially from an aero-thermal point of view.
Life-Limiting Aspects of an Melt-Infiltrated Silicon Carbide Fiber-Reinforced Silicon Carbide Matrix Ceramic Matrix Composite in Interlaminar Shear at Elevated Temperature
Authors: Kane S. , Stanley A. , Sanchez L. , Faucett D. C. , Choi S. R. 
Published: August 2021

Abstract
Life-limiting behavior of a melt-infiltrated (MI) silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) ceramic matrix composite (CMC) was determined under interlaminar shear at 1316 °C in air using double-notch-shear test specimens. The three different shear loading configurations of dynamic fatigue, static fatigue, and cyclic fatigue were employed to assess their individual respective lives. The MI SiC/SiC CMC exhibited low susceptibility to fatigue (“slow crack growth”) regardless of loading configuration. A life prediction model for interlaminar shear in cyclic fatigue was developed based on the fracture mechanics framework. The newly developed cyclic fatigue model as well as the previously developed dynamic and static fatigue models were all in good agreement with the experimental data, indicating that the governing failure mechanism under interlaminar shear was consistent, independent of fatigue loading configuration.
Coupled Calculations of Data Center Cooling and Power Distribution Systems
Authors: Wemhoff Aaron P. , Ahmed Faisal 
Published: August 2021

Abstract
Physics-based modeling aids in designing efficient data center power and cooling systems. These systems have traditionally been modeled independently under the assumption that the inherent coupling of effects between the systems has negligible impact. This study tests the assumption through uncertainty quantification of models for a typical 300 kW data center supplied through either an alternating current (AC)-based or direct current (DC)-based power distribution system. A novel calculation scheme is introduced that couples the calculations of these two systems to estimate the resultant impact on predicted power usage effectiveness (PUE), computer room air conditioning (CRAC) return temperature, total system power requirement, and system power loss values. A two-sample z-test for comparing means is used to test for statistical significance with 95% confidence. The power distribution component efficiencies are calibrated to available published and experimental data. The predictions for a typical data center with an AC-based system suggest that the coupling of system calculations results in statistically significant differences for the cooling system PUE, the overall PUE, the CRAC return air temperature, and total electrical losses. However, none of the tested metrics are statistically significant for a DC-based system. The predictions also suggest that a DC-based system provides statistically significant lower overall PUE and electrical losses compared to the AC-based system, but only when coupled calculations are used. These results indicate that the coupled calculations impact predicted general energy efficiency metrics and enable statistically significant conclusions when comparing different data center cooling and power distribution strategies.
Love Wave or Slip Wave?
Authors: Ranjith Kunnath 
Published: August 2021

Abstract
Conventional models of the structure of the Earth, such as the Preliminary Reference Earth Model (PREM), assume a bonded interface between the crust and the upper mantle. The bonded contact model is consistent with the observation of Love waves during an earthquake. However, anomalies in the Love wave dispersion have been reported in the literature. When slip occurs at the crust-mantle interface, another kind of an interfacial wave, called the slip wave can exist. It is shown that the dispersion relation of the slip wave, with a slip weakening friction law, appears to be in agreement with the observations at seismic frequencies. This suggests that slip could occur at the crust-mantle interface.