bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Moringa oleifera seed extract on antimicrobial activity and in vitro fertilization ability of cryopreserved ram semen
Authors: Guedea‐Betancourt José Julián , Quezada‐Casasola Andrés , Núñez‐Gastélum José Alberto , Orozco‐Lucero Ernesto , Escárcega‐Ávila Angélica María , Soler Valls Ana Josefa , Carrera‐Chávez José Maria 
Published: August 2022

AbstractCryopreservation has adverse effects on the post‐thaw sperm quality due to oxidative stress and the presence of bacteria. To minimize such effects, plant extracts have been included in the composition of the semen diluents. The objective of the present study was to evaluate the antimicrobial and antioxidant effects of Moringa oleifera seed extract (MOSE) on cryopreserved ram semen, as well as its impact on in vitro fertilization. Semen from six hair rams was treated with five treatments before cryopreservation: Control (without any antibiotic), Standard (conventional antibiotic), 1.0, 10.0, and 50.0 mg/ml of MOSE. Post‐thawing sperm characteristics were evaluated by the computer‐assisted semen analysis. Antimicrobial activity was assessed by counting colony‐forming units (CFU) and the antioxidant capacity by the ferric reducing antioxidant power method. A heterologous in vitro fertilization technique was implemented to measure the fertilization rate. Progressive and rapid motility, membrane and acrosome integrity, and active mitochondria were higher (p < .05) in the 10.0 mg/ml treatment compared with Standard after thawing. All M. oleifera treatments showed inhibition of CFU. The antioxidant capacity of M. oleifera seed extract was higher in the 10.0 and 50.0 mg/ml treatments. Fertilization rate (cleavage percentage) was higher (p < .05) in the 10.0 mg/ml (82.9 ± 10.0) and Control (82.5 ± 9.9) treatments compared with Standard (73.7 ± 9.1). The addition of 10.0 mg/ml of MOSE to ram semen inhibits the development of microorganisms and improves sperm characteristics and the in vitro fertility of the semen.
Collective racial resentment and emotion: Toward an understanding of Whites' reactions to demands for racial equity
Authors: Genter Shaun 
Published: August 2022

AbstractThere is a long‐standing debate regarding how whites respond to Black political activists who push for racial equity. Symbolic racism researchers have argued that white reactions result from a blend of racial animus and traditional moral values, while conflict theorists have argued they are more a matter of group interests. Others who take a politics centered approach argue that principled objections rooted in political ideology—not racial considerations—are the driving force. In this article, I outline the history of this debate, with a particular emphasis on the symbolic racism and group conflict perspectives and their theoretical foundations. Efforts to synthesize these perspectives have made a case that both feelings are aspects of whites' sense of group position and might be described as “collective racial resentment.” Drawing on this concept, I argue that whites are likely to be angered by Black political activists because they are perceived to be a threat to the group's position. I then propose the more general concept of “collective racial emotion” to capture contexts where whites may feel paternalistic warmth if they believe their group's position is being protected.
University students' perspectives on emergency online GIS learning amid the Covid‐19 pandemic
Authors: Yan Yingwei , Cai Fangyi , Feng Chen‐Chieh , Chen Yuanyi 
Published: August 2022

AbstractThis study investigated GIS students' perspectives on emergency online learning (EOL) during the Covid‐19 pandemic through a case study at National University of Singapore. Questionnaire surveys administered to three GIS courses were conducted, the result of which suggests that the GIS teaching could be completed effectively online during the crisis. In addition, the positive and negative influences of this learning mode have been discussed in connection to relevant student perspectives on social media and relevant findings in the literature. Relatively, senior and independent learners adapted better to the EOL, while beginners and less self‐disciplined learners may need more face‐to‐face guidance, interactions, and direct supervision. It is worth pointing out that despite some students seeing the demand for a higher level of self‐discipline as being negative, others saw this property contributed to them being better independent learners with self‐motivation, suggesting the need for a nuanced interpretation of the results that consider perspectives. Based on the pros and cons of the EOL investigated, this article further stresses the need to cultivate a post‐pandemic blended GIS learning pedagogy for enhancing higher GIS education's quality and resilience in times of crisis.
Gaza and the Great March of Return: Enduring violence and spaces of wounding
Authors: Jones Craig 
Published: August 2022

AbstractThis paper develops an agenda for political geographical work on violence, war, and trauma. Drawing from an analysis of the Great March of Return, a series of mass demonstrations in the Gaza Strip in 2018 and 2019, it argues that political geography and related fields could be enriched by the concepts of enduring violence and wounding. Enduring violence is offered as a supplement to existing geographical work on slow violence and cognate concepts such as ‘everyday’, banal′, and ‘chronic’ violence, offering fresh ways of understanding the long‐lasting effects of violence and their specific material origins. Wounding is offered as a supplement to political geographical work on necropolitics and the ‘right to kill’, emphasising how a concomitant ‘right to maim’ troubles contemporary theorisations of biopower and necropolitics, and extending geographical work on trauma to include physical bodily trauma. Taken together, the argument is not only that acute (or epidemic) forms of violence can have chronic (or endemic) consequences but also that some forms of harm, like wounding, are characterised by material configurations that are calibrated or otherwise capacitated with the power to impart future harms even in the absence of future ‘blows’. Taking inspiration from geopolitical forensics, enduring violence places new emphasis on the ongoing and lasting harms that inhere in specific geo‐materialities of wounding. The paper concludes with a reflection on the relation between enduring violence and wounding and their implications for geographical work on violence, war, and trauma.
Use of wound edge inversion (epibole) to generate recalcitrant and inflamed diabetic wounds
Authors: Lee Phoebe L. , Loder Shawn J. , Guerrero David T. , Nerone W. Vincent , Bengur Fuat Baris , Rubin J. Peter , Kokai Lauren E. 
Published: August 2022

AbstractRobust and predictive pre‐clinical models of recalcitrant diabetic wounds are critical for advancing research efforts toward improving healing. Murine models have logistic and genetic benefits versus larger animals; however, native murine healing inadequately represents clinically recalcitrant wounds in humans. Furthermore, current humanization techniques employing devices, deleterious mutations or chemical agents each carry model‐specific limitations. To better replicate human wounds in a mouse, we developed a novel wound‐edge inversion (WEI) technique that mimics the architecture of epibole and mitigates contracture, epithelialization, and consequently wound closure. In this study, we evaluated the reliability and durability of the WEI model in wild‐type and obese diabetic mice and compared to healing after (i) punch biopsy, (ii) mechanical/silicone stenting or (iii) exogenous oxidative stressors. In wild‐type mice, WEI demonstrated favourable closure characteristics compared to both control and stented wounds, however, wounds progressed to closure by 4 weeks. In contrast, diabetic WEI wounds persisted for 6–10 weeks with reduced contracture and epithelialization. In both diabetic and wild‐type mice, WEI sites demonstrated persistence of inflammatory populations, absence of epithelialization, and histologic presence of alpha‐SMA positive granulation tissue when compared to controls. We conclude that the WEI technique is particularly valuable for modelling recalcitrant diabetic wounds with sustained inflammation and dysfunctional healing.
Cardiac efficiency and Starling's Law of the Heart
Authors: Han June‐Chiew , Taberner Andrew J. , Loiselle Denis S. , Tran Kenneth 
Published: August 2022

AbstractThe formulation by Starling of The Law of the Heart states that ‘the [mechanical] energy of contraction, however measured, is a function of the length of the muscle fibre’. Starling later also stated that ‘the oxygen consumption of the isolated heart … is determined by its diastolic volume, and therefore by the initial length of its muscular fibres’. This phrasing has motivated us to extend Starling's Law of the Heart to include consideration of the efficiency of contraction. In this study, we assessed both mechanical efficiency and crossbridge efficiency by studying the heat output of isolated rat ventricular trabeculae performing force–length work‐loops over ranges of preload and afterload. The combination of preload and afterload allowed us, using our modelling frameworks for the end‐systolic zone and the heat–force zone, to simulate cases by recreating physiologically feasible loading conditions. We found that across all cases examined, both work output and change of enthalpy increased with initial muscle length; hence it can only be that the former increases more than the latter to yield increased mechanical efficiency. In contrast, crossbridge efficiency increased with initial muscle length in cases where the extent of muscle shortening varied greatly with preload. We conclude that the efficiency of cardiac contraction increases with increasing initial muscle length and preload. An implication of our conclusion is that the length‐dependent activation mechanism underlying the cellular basis of Starling's Law of the Heart is an energetically favourable process that increases the efficiency of cardiac contraction.imageKey pointsErnest Starling in 1914 formulated the Law of the Heart to describe the mechanical property of cardiac muscle whereby force of contraction increases with muscle length.He subsequently, in 1927, showed that the oxygen consumption of the heart is also a function of the length of the muscle fibre, but left the field unclear as to whether cardiac efficiency follows the same dependence.A century later, the field has gained an improved understanding of the factors, including the distinct effects of preload and afterload, that affect cardiac efficiency. This understanding presents an opportunity for us to investigate the elusive length‐dependence of cardiac efficiency.We found that, by simulating physiologically feasible loading conditions using a mechano‐energetics framework, cardiac efficiency increased with initial muscle length.A broader physiological importance of our findings is that the underlying cellular basis of Starling's Law of the Heart is an energetically favourable process that yields increased efficiency.
El cerebro del meditador de atención plena: de la prospección a la tarea
Authors: Pelaez Lopez Maria Antonia , Lozano Zuluaga Juan José , Narváez Andrade María José , Becerra Hernández Lina Vanessa 
Published: August 2022

La meditación de atención plena es una técnica originaria de la cultura budista, la cual busca “cosechar la conciencia interior”, centrando la atención en el aquí y en el ahora, aceptando los pensamientos y dejándolos fluir. A través de diferentes estudios se ha evidenciado sus beneficios a nivel del sistema nervioso central, cuyos mecanismos aún no están dilucidados. En la presente revisión se recopila información de estudios que han utilizado resonancia magnética nuclear, morfometría basada en voxel, resonancia magnética funcional y electroencefalograma para valorar los mismos. Dentro de los cambios imagenológicos reportados se encontraron cambios corticales importantes, incluyendo cambios que abarcan engrosamiento de corteza prefrontal, ínsula e incremento en volúmenes hipocampales, además de cambios en el estriado, la corteza cingulada posterior y el precúneo; estructuras involucradas en el control de las emociones, en la memoria, la atención y el aprendizaje. En cuanto a lo evidenciado con el electroencefalograma, al estudiar los cambios funcionales de la actividad eléctrica del cerebro los resultados han sido poco concluyentes, sin embargo, las ondas alpha y theta destacaron sobre el resto, mostrando una mayor amplitud en los practicantes de meditación de atención plena.
El riesgo de recién nacidos expuestos a eventos de morbilidad materna extrema en un centro de alto riesgo obstétrico (Colombia)
Authors: Puello Ávila Antonio Carlos , Rodríguez Ortiz Jorge Augusto , Giraldo Méndez Néstor , Castro Herrera Lina Maria 
Published: August 2022

RESUMEN
Introducción: Una atención oportuna y de calidad en una mujer con una complicación obstétrica severa puede prevenir un desenlace fatal. Se estima que dos de cada tres defunciones neonatales son evitables con medidas eficaces en la atención del parto. El objetivo fue determinar el riesgo de exposición de los hijos de madres con eventos de morbilidad materna extrema. Materiales y métodos: Estudio de análisis secundario de datos. La población de estudio incluyó los 2197 registros de nacidos vivos y 103 registros de notificación de morbilidad materna extrema. Resultados: La prevalencia de morbilidad materna extrema fue 5,3%. Los neonatos con un peso entre 3500-4000 gr y > 4000 gr tenían menor riesgo con relación a exposición a morbilidad materna extrema en comparación con el peso < 2500 gr. Así mismo, el riesgo de exposición fue menor en los partos a término en comparación con los pretérmino. Conclusiones: Existe asociación entre morbilidad materna y resultados perinatales adversos; con un riesgo significativamente mayor de parto prematuro, bajo peso al nacer, y más tasas de cesárea. Palabras claves: Morbilidad materna severa; Neonatos; mortalidad perinatal; Embarazo; Riesgo (fuente DeCS).
A Reactor Train System for Efficient Solar Thermochemical Fuel Production
Authors: Patankar Aniket S. , Wu Xiao-Yu , Choi Wonjae , Tuller Harry L. , Ghoniem Ahmed F. 
Published: August 2022

AbstractThermochemical redox cycles are a promising route to producing solar fuels. In this work, a novel reactor train system (RTS) is proposed for the efficient conversion of solar thermal energy into hydrogen. This system is capable of recovering thermal energy from redox materials, which is necessary for achieving high efficiency but has been difficult to realize in practice. The RTS overcomes technical challenges of high-temperature thermochemical reactors like solid conveying and sealing, while enabling continuous fuel production and efficient oxygen removal during metal oxide reduction. The RTS is comprised of several identical reactors arranged in a closed loop and cycling between reduction and oxidation steps. In between these steps, the reactors undergo solid heat recovery in a counterflow radiative heat exchanger. The RTS can achieve heat recovery effectiveness of 80% for a train producing 100 kg-H2/day with a 60 min cycle time. The RTS can take advantage of thermal energy storage to operate round-the-clock. Further, it implements waste heat recovery to capture the exothermic heat of water-splitting. If all auxiliary energy demands can be satisfied with such waste heat, the RTS base configuration achieves 30% heat-to-hydrogen conversion efficiency, which is more than four times that of current state-of-the-art thermochemical systems.
Efficiency Improvement of Photovoltaic Solar Modules by Cooling Using an Underground Heat Exchanger
Authors: Valiente-Blanco Ignacio , Lopez-Pascual Diego , Diaz-Villar Pablo , Mallol-Poyato Ricardo , Barragan Alberto , Ocaña Manuel , Granello Guido , Diez-Jimenez Efren 
Published: August 2022

Abstract
Overheating of solar cells under normal operational conditions highly reduces their energy harvesting efficiency and produces additional problems related to thermal cycling and performance degradation of the modules. In this paper, a novel cooling system for solar photovoltaics, using the underground as a heat sink, is proposed, theoretically described and experimentally validated. A prototype of the technology (including a single-axis sun tracking mechanism) has been designed, manufactured, and rigorously tested in outdoor conditions during summer 2021 in Spain, under different environmental conditions. The excess heat is removed from the backside of the solar module by a close-loop and single-phase cooling system and then dissipated in the underground, which is at a constant temperature of about 16 °C at relatively low depths at the location where tests were performed. A single U-shaped copper tube, 18 mm in diameter, immersed in a 15.5-m-deep borehole naturally filled with water, is used as an underground heat exchanger. As a consequence of the reduction of the cooled module temperature, its net power generation is significantly increased. A promising improvement of the net power generation of the cooled solar module up to 12.4% has been measured for a coolant flowrate of 1.84 l/min per square meter of solar module, proving the technical feasibility of the approach. In addition, a dependency of the power gain with the pump efficiency, the global radiation, and ambient temperature has been observed.
Effects of Chevron Micro-Textures on Tribological and Lubricating Performance of Cylinder Block/Valve Plate Interface in Axial Piston Pumps
Authors: Chen Luanxia , Shang Lizhi , Liu Zhanqiang , Mukherjee Swarnava , Cai Yukui , Wang Bing 
Published: August 2022

Abstract
The cylinder block/valve plate interface is one of the major power loss sources and main failure points in axial piston pumps and motors. Surface micro-texture has been proven to be an effective approach to reduce friction and wear in many tribological applications. In the present paper, the effect of micro-texture on the tribological and lubricating performance of the important cylinder block/valve plate interface is studied experimentally and numerically. The experimental investigation was conducted on a disk-on-disk tribometer with similar geometry, operating speed, material, and working fluid to the cylinder block/valve plate interface in the axial piston pump. The tribological test results confirmed the chevron micro-texture's potential to reduce frictional loss in such lubricating interface. Furthermore, a novel numerical method coupling the dynamic loading, squeeze motion, analytical pressure deformation, mixed friction, and cavitation was proposed to study the lubricating performance of micro-textured valve plate/cylinder block interface. This model was then validated comparing to the tribometer experimental results and was used to study the effect of depths, widths, and distances of chevron micro-textures on the lubrication performance of cylinder block/valve plate interface. The results found that the depth of the chevron micro-textures affected whether the cavitation occurred inside the micro-texture, the width of the chevron micro-texture affected the size of the cavitation area that occurred in the micro-textures, and the chevron micro-texture distance affected the size of the convergence zone where positive pressure generated.
Nonlinear Vibration Analysis of a Generally Restrained Axially Loaded Beam Structure With a Local Uniform Nonlinear Foundation
Authors: Du Jingtao , Zhao Yuhao , Chen Yilin , Liu Yang 
Published: August 2022

Abstract
Beam structures are widely used in various engineering occasions to model various structures. Numerous researchers have studied dynamic responses of beam structures with nonlinear supports or nonlinear foundations. In engineering, nonlinear supports were subjected to the beam structure through the surface contact rather than the point connection. Few works studied the dynamic behavior of the beam structure with local uniform cubic nonlinear stiffness foundations. Additionally, the boundary rotational restraints of the beam structure are ignored. To improve the engineering acceptance of the beam structure with nonlinearity, it is of great significance to study the dynamic behavior of the generally restrained axially loaded beam structure with a local uniform nonlinear foundation. This work establishes a nonlinear dynamic model of the beam structure with a local uniform nonlinear foundation. Dynamic responses of the beam structure are predicted through the Galerkin truncated method. In Galerkin truncated method, mode functions of the axially loaded beam structure without the local uniform nonlinear foundation are selected as the trail and weight functions. The harmonic balance method is employed to verify the correctness of the Galerkin truncated method. The influence of the sweeping ways and local uniform nonlinear foundation on dynamic responses of the generally restrained axially loaded beam structure is investigated. Dynamic responses of the generally restrained axially loaded beam structure with a local uniform nonlinear foundation are sensitive to its calculation initial values. Suitable parameters of the local uniform nonlinear foundation can suppress the vibration response and transform the vibration state of the beam structure.
Multifidelity Physics-Constrained Neural Networks With Minimax Architecture
Authors: Liu Dehao , Pusarla Pranav , Wang Yan 
Published: August 2022

Abstract
Data sparsity is still the main challenge to apply machine learning models to solve complex scientific and engineering problems. The root cause is the “curse of dimensionality” in training these models. Training algorithms need to explore and exploit in a very high-dimensional parameter space to search the optimal parameters for complex models. In this study, a new scheme of multifidelity physics-constrained neural networks with minimax architecture is proposed to improve the data efficiency of training neural networks by incorporating physical knowledge as constraints and sampling data with various fidelities. In this new framework, fully connected neural networks with two levels of fidelities are combined to improve the prediction accuracy. The low-fidelity neural network is used to approximate the low-fidelity data, whereas the high-fidelity neural network is adopted to approximate the correlation function between the low-fidelity and high-fidelity data. To systematically search the optimal weights of various losses for reducing the training time, the Dual-Dimer algorithm is adopted to search high-order saddle points of the minimax optimization problem. The proposed framework is demonstrated with two-dimensional heat transfer, phase transition, and dendritic growth problems, which are fundamental in materials modeling. With the same set of training data, the prediction error of the multifidelity physics-constrained neural network with minimax architecture can be two orders of magnitude lower than that of the multifidelity neural network with minimax architecture.