bluuebunny/crossref_metadata_2025_split huggingface dataset:
Royal jelly may improve sperm characteristics during preservation of rooster semen: Gene expression of antioxidant enzymes
Authors: Hadavand Mirzaei Atefeh , Deldar Hamid , Ansari Pirsaraei Zarbakht , Shohreh Bahram 
Published: January 2021

AbstractSustainable production and the increasing number of embryonated hatching eggs are critical aspects of the poultry production industry. The present paper aims to appraise the effectiveness of royal jelly (RJ) on the semen characteristics of Native Mazandaran roosters in both liquid and frozen storage conditions. Semen collected from 10 sexually mature roosters and following dilution was supplemented with RJ at 0.0 (control), 5 (RJ5), 10 (RJ10), 20 (RJ20) and 40 (RJ 40) mg/ml. After cooling and freezing‐thawing, the percentage of forward progressive motility, viability, abnormality, hypo‐osmotic swelling test (HOST) and the mRNA abundance of antioxidant enzymes of spermatozoa were measured. Our results revealed that the addition of 5 mg/ml RJ to the semen extender significantly increased (p < .05) the percentages of forward progressive motility, viability and HOST during liquid and frozen storage. The abnormality of spermatozoa in the RJ5 group was significantly lower compared to the other groups. During liquid storage, a significant decrease in forward progressive motility was found after 48 hr in comparison with 24 hr at 4°C. High levels of RJ (from 10 to 40 mg/ml) were severely decreased the characteristics of rooster spermatozoa in comparison with RJ5 and the control group. The inclusion of RJ at 5 mg/ml to the semen extender enhanced the mRNA transcript of antioxidant enzymes of spermatozoa during liquid preservation. The mRNA abundance of antioxidant enzymes did not influence by cryostorage. Overall, these data suggest that supplementation of RJ at 5 mg/ml to the extender improved semen characteristics and redox status of rooster spermatozoa.
Spatio-Temporal Mixed Membership Models for Criminal Activity
Authors: Virtanen Seppo , Girolami Mark 
Published: January 2021

Abstract
We suggest a probabilistic approach to study crime data in London and highlight the benefits of defining a statistical joint crime distribution model which provides insights into urban criminal activity. This is achieved by developing a hierarchical mixture model for observations, crime occurrences over a geographical study area, that are grouped according to multiple time stamps and crime categories. The mixture components correspond to spatial crime distributions over the study area and the goal is to infer, based on the observations, how and to what degree the latent distributions are shared across the groups.
Changes in the autonomic and respiratory patterns in mice submitted to short‐term sustained hypoxia
Authors: Rodrigues Karla L. , Souza Juliana R. , Bazilio Darlan S. , de Oliveira Mauro , Moraes Melina P. S. , Moraes Davi J. A. , Machado Benedito H. 
Published: January 2021

New Findings

What is the central question of this study?
Do mice submitted to sustained hypoxia present autonomic and respiratory changes similarly to rats?

What is the main finding and its importance?
Arterial pressure in the normal range, reduced baseline heart rate and tachypnoea were observed in behaving sustained hypoxia mice. Recordings in the in situ preparation of mice submitted to sustained hypoxia show an increase in cervical vagus nerve activity and a simultaneous reduction in thoracic sympathetic nerve activity correlated with changes in the respiratory cycle. Therefore, mice are an important model for studies on the modulation of sympathetic activity to the cardiovascular system and the vagus innervation of the upper airways due to changes in the respiratory network induced by sustained hypoxia.

AbstractShort‐term sustained hypoxia (SH) in rats induces sympathetic overactivity and hypertension due to changes in sympathetic–respiratory coupling. However, there are no consistent data about the effect of SH on mice due to the different protocols of hypoxia and difficulties associated with the handling of these rodents under different experimental conditions. In situ recordings of autonomic and respiratory nerves in SH mice have not been performed yet. Herein, we evaluated the effects of SH ( = 0.1 for 24 h) on baseline mean arterial pressure (MAP), heart rate (HR), respiratory frequency (fR) and responses to chemoreflex activation in behaving SH mice. A characterization of changes in cervical vagus (cVN), thoracic sympathetic (tSN), phrenic (PN) and abdominal (AbN) nerves in SH mice using the in situ working heart–brainstem preparation was also performed. SH mice presented normal MAP, significant reduction in baseline HR, increase in baseline fR, as well as increase in the magnitude of bradycardic response to chemoreflex activation. In in situ preparations, SH mice presented a reduction in PN discharge frequency, and increases in the time of expiration and incidence of late‐expiratory bursts in AbN activity. Nerve recordings also indicated a significant increase in cVN activity and a significant reduction in tSN activity during expiration in SH mice. These findings make SH mice an important experimental model for better understanding how changes in the respiratory network may impact on the modulation of vagal control to the upper airways, as well as in the sympathetic activity to the cardiovascular system.
The effect of time‐of‐day and circadian phase on vulnerability to seizure‐induced death in two mouse models
Authors: Purnell Benton S. , Petrucci Alexandra N. , Li Rui , Buchanan Gordon F. 
Published: January 2021

Key points
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of premature death in patients with refractory epilepsy.
SUDEP typically occurs during the night, although the reason for this is unclear.
We found that, in normally entrained mice, time‐of‐day alters vulnerability to seizure‐induced death.
We found that, in free‐running mice, circadian phase alters the vulnerability to seizure‐induced death.
These findings suggest that circadian rhythmicity may be responsible for the increased night‐time prevalence of SUDEP
AbstractSudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy‐related death. SUDEP typically occurs during the night following a seizure. Many aspects of mammalian physiology are regulated by circadian rhythms in ways that might make seizures occuring during the night more dangerous. Using two mouse models of seizure‐induced death, we demonstrate that time‐of‐day and circadian rhythms alter vulnerability to seizure‐induced death. We exposed normally entrained DBA/1 mice to a potentially seizure‐inducing acoustic stimulus at different times of day and compared the characteristics and outcomes of the seizures. Time‐of‐day did not alter the probability of a seizure but it did alter the probability of seizure‐induced death. To determine whether circadian rhythms alter vulnerability to seizure‐induced death, we induced maximal electroshock seizures in free‐running C57BL/6J mice at different circadian time points at the same time as measuring breathing via whole body plethysmography. Circadian phase did not affect seizure severity but it did alter postictal respiratory outcomes and the probability of seizure‐induced death. By contrast to our expectations, in entrained and free‐running mice, vulnerability to seizure‐induced death was greatest during the night and subjective night, respectively. These findings suggest that circadian rhythmicity may be responsible for the increased night‐time prevalence of SUDEP and that the underlying mechanism is phase conserved between nocturnal and diurnal mammals. All of the seizures in the present study were induced during wakefulness, indicating that the effect of time point on vulnerability to seizure‐induced death was not the result of sleep. Understanding why SUDEP occurs more frequently during the night may inform future preventative countermeasures.
Physiology of physical inactivity, sedentary behaviours and non‐exercise activity: insights from the space bedrest model
Authors: Le Roux Elisa , De Jong Nathan P. , Blanc Stéphane , Simon Chantal , Bessesen Daniel H. , Bergouignan Audrey 
Published: January 2021

AbstractPhysical inactivity, i.e. not reaching the recommended level of physical activity (PA), and sedentary behaviours (SB), i.e. sitting time, have been associated with increased risk for common metabolic diseases. Recent epidemiological data suggest that high volumes of SB are detrimental to metabolic health, even in the presence of regular exercise, i.e. moderate/vigorous PA. This suggests that the health effects of SB are independent from those of exercise. However, experimentally testing this hypothesis is complicated because of the difficulty in disassociating SB from PA. Bedrest studies, a traditional space science model, can offer new insights. In some bedrest studies, an exercise training protocol has been used to counteract the harmful effects of inactivity. While bedrest induces an inactive and sedentary state, exercise with bedrest represents a unique model of sedentary yet physically active people. Here, we review bedrest studies with and without exercise training. Although exercise training prevents the loss of muscle mass and function, even large volumes of exercise are not sufficient to fully counteract the negative metabolic adaptations triggered by inactivity. This observation supports the existence of independent adverse health effects of SB, but also the potential benefits of non‐exercise activity, i.e. daily living light PA. We gathered available data to examine the complex relationships between exercise, non‐exercise activity, SB and health outcomes. Given the large amount of SB in modern societies, the sole promotion of exercise, i.e. moderate/vigorous PA may be insufficient, and promotion of light PA may be a complimentary approach to improve health.
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Experimental Investigation on Heat Transfer and Friction Factor in Open Matrix Subchannels
Authors: Prajapati Anjana N. , Tariq Andallib 
Published: January 2021

Abstract
Matrix cooling has opened new possibilities for enhancing the convective heat transfer coefficients without compromising upon the structural rigidity and the life of the gas turbine blade at elevated temperatures. However, the dense structure of the matrix significantly increases the flow resistance and imposes the limitation to its usage. Recently, a matrix with a gap on the sidewalls called open matrix has been proposed by few researchers to reduce the associated pressure penalties. This detailed experimental investigation aims to study the open matrix channel flow and presents the effects of varying sidewall gaps on heat transfer characteristics and friction factor in the open matrixes having rib angle 45 deg for three different subchannel aspect ratios 1.2, 0.8, and 0.4. Liquid crystal thermography has been utilized to discern the detailed heat transfer characteristics. The results have been evaluated in terms of augmentation Nusselt number, friction factor ratio, and overall thermal performance factor over the Reynolds numbers 5800–14,000. The closed matrixes provided the highest augmentation in Nusselt number, and the gaps on the sidewall have shown an overall reduction in augmentation Nusselt number in most cases. However, the suitable sidewall gaps show the effective reduction in pressure penalties for the smaller subchannel aspect ratios. The highest augmentation Nusselt number among the open matrixes has been found as 3.83 with a reduced friction factor ratio for the matrix with a 4-mm gap in subchannel aspect ratio = 0.8 (i.e., 4 subchannels) at Re = 8100.
Biomechanical Study of Cervical Disc Arthroplasty Devices Using Finite Element Modeling
Authors: Yoganandan Narayan , Purushothaman Yuvaraj , Choi Hoon , Baisden Jamie , Rajasekaran Deepak , Banerjee Anjishnu , Jebaseelan Davidson , Kurpad Shekar 
Published: January 2021

Abstract
Many artificial discs for have been introduced to overcome the disadvantages of conventional anterior discectomy and fusion. The purpose of this study was to evaluate the performance of different U.S. Food and Drug Administration (FDA)-approved cervical disc arthroplasty (CDA) on the range of motion (ROM), intradiscal pressure, and facet force variables under physiological loading. A validated three-dimensional finite element model of the human intact cervical spine (C2-T1) was used. The intact spine was modified to simulate CDAs at C5-C6. Hybrid loading with a follower load of 75 N and moments under flexion, extension, and lateral bending of 2 N·m each were applied to intact and CDA spines. From this work, it was found that at the index level, all CDAs except the Bryan disc increased ROM, and at the adjacent levels, motion decreased in all modes. The largest increase occurred under the lateral bending mode. The Bryan disc had compensatory motion increases at the adjacent levels. Intradiscal pressure reduced at the adjacent levels with Mobi-C and Secure-C. Facet force increased at the index level in all CDAs, with the highest force with the Mobi-C. The force generally decreased at the adjacent levels, except for the Bryan disc and Prestige LP in lateral bending. This study demonstrates the influence of different CDA designs on the anterior and posterior loading patterns at the index and adjacent levels with head supported mass type loadings. The study validates key clinical observations: CDA procedure is contraindicated in cases of facet arthroplasty and may be protective against adjacent segment degeneration.
Best Architecture of an Artificial Neural Network to Model Prefilming Airblast Atomization: Not So Deep Learning
Authors: Chaussonnet G. , Gepperth S. , Holz S. , Koch R. , Bauer H.-J. 
Published: January 2021

Abstract
A fully connected artificial neural network (ANN) is used to predict the spray characteristics of prefilming airblast atomization. The model is trained from the planar prefilmer experiment from the Ph.D. thesis of Gepperth [Experimentelle Untersuchung des Primärzerfalls an generischen luftgestützten Zerstäubern unter Hochdruckbedingungen, Vol. 75. Logos Verlag Berlin GmbH], in which shadowgraphy images of the liquid breakup at the atomizing edge capture the characteristics of the primary droplets and the ligaments. The quantities extracted from the images are the Sauter Mean Diameter, the mean droplet axial velocity, the mean ligament length, and the mean ligament deformation velocity. These are the prescribed output of the ANN model. In total, the training database contains 322 different operating points at which different prefilmers, liquid types, ambient pressures, film loadings, and gas velocities were investigated. Two types of model input quantities are investigated. First, nine dimensional parameters related to the geometry, the operating conditions, and the properties of the liquid are used as inputs for the model. Second, nine nondimensional groups commonly used for liquid atomization are derived from the first set of inputs. These two types of inputs are compared. The architecture providing the best fitting is determined after testing over 10,000 randomly drawn ANN architectures, with up to 10 layers and up to 128 neurons per layer. The striking results is that for both types of model, the best architectures consist of a shallow net with the hidden layers in the form of a diabolo: three layers with a large number of neurons (≥24) in the first and the last layers, and very few neurons (≈12) in middle layer. This shape recalls the shape of an auto-encoder, where the middle layer would be the feature space of reduced dimensionality. The trend highlighted by our results, to have a limited number of layers, is in contrast with recent observations in deep learning applied to computer vision and speech recognition. It was found that the model with dimensional input quantities always shows a lower test and validation errors than the one with nondimensional input quantities. The best architectures for both types of inputs (dimensional and nondimensional input) were tested versus the experiments. Both provide comparable accuracy, which is better than typical correlations of Sauter mean diameter (SMD) and droplet velocity. As the models take more input parameters into account compared to the correlations, they can predict the experimental data more accurately. Finally, the extrapolation capability of the models was assessed by training them on a confined domain of parameters and testing them outside this domain. It was found that the models can extrapolate at larger gas velocity. With a larger ambient pressure or a lower trailing edge thickness, the accuracy decreases drastically.
Implications of Phase Change on the Aerodynamics of Centrifugal Compressors for Supercritical Carbon Dioxide Applications
Authors: Persico Giacomo , Gaetani Paolo , Romei Alessandro , Toni Lorenzo , Bellobuono Ernani Fulvio , Valente Roberto 
Published: January 2021

Abstract
Closed Joule–Brayton cycles operating with carbon dioxide in supercritical conditions (sCO2) are nowadays collecting a significant scientific interest, due to their high potential efficiency, the compactness of their components, and the flexibility that makes them suitable to exploit diverse energy sources. However, the technical implementation of sCO2 power systems introduces new challenges related to the design and operation of the components. The compressor, in particular, operates in a thermodynamic condition close to the critical point, whereby the fluid exhibits significant non-ideal gas effects and is prone to phase change in the intake region of the machine. These new challenges require novel design concepts and strategies, as well as proper tools to achieve reliable predictions. In this study, we consider an exemplary sCO2 power cycle with the main compressor operating in proximity to the critical point, with an intake entropy level of the fluid lower than the critical value. In this condition, the phase change occurs as evaporation/flashing, thus resembling cavitation phenomena observed in liquid pumps, even though with specific issues associated with compressibility effects occurring in both the phases. The flow configuration is therefore highly nonconventional and demands the development of proper tools for fluid and flow modeling, which are instrumental for the compressor design. The paper discusses the modeling issues from the thermodynamic perspective, then highlighting their implications on compressor aerodynamics. We propose tailored models to account for the effect of the phase change in 0D mean-line design tools as well as in fully three-dimensional (3D) computational fluid-dynamic (CFD) simulations: the former was previously validated for sCO2 compressors, the latter is validated in this paper against experiments of compressible flows of supercritical sCO2 in nozzles. In this way, a strategy of investigation is built-up as a combination of mean-line tools, industrial design experience, and CFD for detailed flow analysis. The investigation reveals that the potential onset of the phase change might alter significantly the performance and operation of the compressor, both in design and in off-design conditions, according to three main mechanisms: incidence effect, front-loading, and channel blockage.
Experimental Characterization of Two-Phase Cold Plates Intended for High-Density Data Center Servers Using a Dielectric Fluid
Authors: Ramakrishnan Bharath , Hoang Cong Hiep , Khalili Sadegh , Hadad Yaser , Rangarajan Srikanth , Pattamatta Arvind , Sammakia Bahgat 
Published: January 2021

Abstract
High-performance computing (HPC) data centers demand cutting edge cooling techniques like direct contact liquid cooling (DCLC) for safe and secure operation of their high-power density servers. The two-phase flow boiling heat transfer technique is widely believed to address the heating problem posed by HPC racks. In this study, a novel liquid-cooled cold plate containing microchannel and jet impingement arrangement was characterized for its two-phase flow and thermal behavior. A sophisticated bench top setup involving a mock package was developed to carry out the experiments in a controlled fashion using a dielectric fluid Novec/HFE-7000. Two-phase flow boiling in cold plates which has a strong dependency on surface phenomena were carefully studied at various levels of inlet pressure, subcooling, flow rates, and heat flux levels to the mock package. A resistance network was invoked to determine the average heat transfer coefficient at various exit qualities estimated by the energy balance equation. While the results make it evident that, the high heat generating components can be kept at operable conditions using the two-phase cooling; a deeper insight at the outcomes could pave way for more energy efficient cold plate designs. The experiment was carried out with a large heated surface of 6.45 cm2 and maximum dissipated heat flux was around 63.6 W/cm2 corresponding to chip power of 410 W. Base temperature was kept below 75 °C and pressure drop did not exceed 21 kPa.
Experimental and Model Studies of Various Size Water Droplet Impacting on a Hydrophobic Surface
Authors: Abubakar Abba Abdulhamid , Yilbas Bekir Sami , Hussain A-Qahtani M. , Hassan Ghassan , Yakubu Mubarak , Bahatab Saeed , Adukwu John A. E. 
Published: January 2021

Abstract
Impacting droplet on a hydrophobic surface is investigated and droplet size effect on impacting properties is examined. Liquid pressure variation inside droplet is numerically simulated in the impacting and rebounding periods. Droplet motion on impacted hydrophobic surface is monitored using a high-speed recording system. We showed that predictions and high-speed data for droplet shape and geometric features appear to be almost identical in the spreading and retraction of the droplet on sample surface. Increased volume of droplet gives rise to the peak pressure enhancement in droplet liquid during impact. The maximum droplet height remains larger for large volume droplets in both spreading and retraction cycles. Increasing size of droplet enlarges the wetting diameter on the impacted surface during droplet deformation on sample surfaces. The rate of peak velocity of the spreading surface of the droplet is faster for larger droplets as compared to that corresponding to small droplets. The ratio of spreading period over the retraction period of the droplet becomes small for droplets with small size.
Unsteady Hemodynamics in Intracranial Aneurysms With Varying Dome Orientations
Authors: Usmani Abdullah Y. , Muralidhar K. 
Published: January 2021

Abstract
Fluid loading within an intracranial aneurysm is difficult to measure but can be related to the shape of the flow passage. The outcome of excessive loading is a fatal hemorrhage, making it necessary for early diagnosis. However, arterial diseases are asymptomatic and clinical assessment is a challenge. A realistic approach to examining the severity of wall loading is from the morphology of the aneurysm itself. Accordingly, this study compares pulsatile flow (Reynolds number Re = 426, Womersley number Wo = 4.7) in three different intracranial aneurysm geometries. Specifically, the spatio-temporal movement of vortices is followed in high aspect ratio aneurysm models whose domes are inclined along with angles of 0, 45, and 90 deg relative to the plane of the parent artery. The study is based on finite volume simulation of unsteady three-dimensional flow while a limited set of particle image velocimetry experiments have been carried out. Within a pulsatile cycle, an increase in inclination (0–90 deg) is seen to shift the point of impingement from the distal end toward the aneurysmal apex. This change in flow pattern strengthens helicity, drifts vortex cores, enhances spatial displacement of the vortex, and generates skewed Dean's vortices on transverse planes. Patches of wall shear stress and wall pressure shift spatially from the distal end in models of low inclination (0–45 deg) and circumscribe the aneurysmal wall for an inclination angle of 90 deg. Accordingly, it is concluded that high angles of inclination increase rupture risks while lower inclinations are comparatively safe.