bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Allocation Method of Distributed Generation in Active Distribution Network Based on Bi-level Programming
Authors: Zhao Yating , Wu Zhi
Published: May 2022

The optimal allocation method to distributed generation(DG) of active distribution network was studied. Firstly, a bi-level programming model of DG in active distribution network is established. For the cause of determining the optimal installation location and capacity of DG, the upper layer model considers the minimum cost of DG investors as the objective, and the decision variables are the installation location and capacity of DG. The lower layer model considers the system operation with the objective of minimizing the network loss. The decision variables include the voltage amplitude and phase angle of each node and the consumption of distributed generation. Secondly, an modified grey wolf algorithm is proposed to solve the lower layer model, and the lower layer model is turned to a second-order cone programming problem by convex relaxation and linearization technology. Finally, the bi-level programming model developed in this paper is verified by taking IEEE33 bus system as an example, and the simulation results verify the effectiveness of the proposed method.
Metamorphic Relation Recognition Method Based on Control Flow Graph Features
Authors: Li Cong , Liu Jie , Yang Xiaohua , Yan Shiyu , Li Meng
Published: May 2022

Metamorphic testing is an effective method to solve Oracle problems. It is used to test software which is no expected output or the expected output is difficult to construct. However, finding a suitable and effective metamorphic relation in the program is still a very difficult task, usually obtained by domain experts through manual analysis, which greatly reduces the efficiency of software testing. In this work we define a function parameter metamorphic relation from the operation of the function parameter sequence, and preset 10 function parameter metamorphic relation. Because functions with the same structure usually have the same function parameter metamorphic relation, we extract node features and independent path features from the control flow graph, and then create a classification model to judge the similarity between functions. Our experiment includes the evaluation of the prediction model and the prediction of the metamorphic relation on the real function. Good experimental results shows that this method can provides a new way to automated discovery of metamorphic relation.
Hydraulic and Pneumatic Transmission Three-Dimensional Virtual Training System Research
Authors: Ji Tian , Ren Boming , Huang Shengli
Published: May 2022

Unity Three-Dimensiongal technology is used to develop a 3D virtual training system platform for hydraulic and pneumatic transmission circuits, which realizes the simulation of basic hydraulic and pneumatic transmission circuits. The Physically Based Redering process is applied to map the 3D model created by 3DMax software, and the Unity 3D virtual scene technology is used to create the experimental 3D virtual scene and drive the model interactively. The finite state machine design pattern is applied to User Interface management, model selection and scene switching. The Model-View-Controller framework is used to determine the correctness of the linkage, and the mediator pattern is used to control the interaction of the components using buttons. The practical application shows that the system can show the working principle of hydraulics and pneumatics well, and the students can build and interact with the basic circuit to achieve the effect similar to the actual experiment.
Generalized Gelfand-Dikii equation for fermionic Schwinger pair production
Authors: Ahmadiniaz N , Kim S P , Schubert C
Published: May 2022

Schwinger pair creation in a purely time-dependent electric field can be reduced to an effective quantum mechanical problem using a variety of formalisms. Here we develop an approach based on the Gelfand-Dikii equation for scalar QED, and on a generalization of that equation for spinor QED. We discuss a number of solvable special cases from this point of view. In previous work, two of the authors had shown for the scalar case how to use the well-known solitonic solutions of the KdV equation to construct Poschl-Teller like electric fields that do not pair create at some fixed but arbitrary momentum. Here, we present numerical evidence that this construction can be adapted to the fermionic case by a mere change of parameters.
From theory to precision modelling of strong-field QED in the transition regime
Authors: Macleod Alexander J.
Published: May 2022

The combination of energetic electron beams, delivered from conventional accelerators at a high repetition rate, and ultraintense lasers, makes it possible to perform precision measurements of strong-field QED. The LUXE collaboration aims to perform precision measurements of nonlinear Compton scattering and Breit-Wheeler pair creation in the transition from the perturbative to nonperturbative regimes. Here we present an overview of recent developments in the modelling of strong-field QED processes, which are needed to reach the required precision of a few percent for intensity parameters 0.1 < ξ < 10. We discuss how to go from plane-wave QED results to numerical simulations and present predicted signals and error estimates.
Research on damage monitoring of sandwich armor composite structure based on time reversal principle
Authors: Jia Li’An , Gao Shang , Jiang Jian , Zhang Meng
Published: May 2022

With the wide application of lightweight armor composite, it is of great significance to monitor delamination damage in laminated materials. Ultrasonic testing often needs to be immersed in liquid for monitoring, which is inconvenient for large-size specimens and cannot be monitored in real time. In structural health monitoring, the corresponding relationship between damage and response signal characteristics (such as amplitude and energy) is established, which is greatly affected by various environmental factors (such as temperature and load). Due to the particularity of the multi-layer composite structure with large thickness, the problem of Lamb wave multi-mode and frequency dispersion affects the accuracy of damage monitoring, which brings great difficulty to the accuracy of damage monitoring. Four piezoelectric sensors were arranged on the surface of the 5 mm sandwich armor composite composed of alumina ceramic, T700 carbon fiber and TC4 titanium alloy. The signal-to-noise ratio of the obtained damage scattering signal was improved by time reversal method and Gabor wavelet transform. Monitoring and imaging of single damage and multiple damage on the reverse side of armor composite were studied. The experimental results show that the radial error of single damage location is 4.24 mm, and the radial error of multiple damage location is 5.39 mm.
Effect of MnO2 on Low-Temperature Sintered Al2O3 Ceramics
Authors: Wu Zhicong , Lang Xianji , Cai Jie , Wu Maoliang
Published: May 2022

In this paper, MnO2 is used as the sintering aid for alumina (Al2O3) ceramics, and 3D printing and atmospheric sintering are used to study the sintering performance of alumina ceramics at 1300 °C, 1350 °C and 1400 °C by the content of different manganese oxide. Impact. Through experimental analysis, it is concluded that when the content of MnO2 sintering aid is 0-2.4 percent, it can promote the sintering performance of alumina ceramics; and when the sintering temperature is 1350 °C, alumina ceramics has better performance under SEM electron microscope morphology.
Study on Model of Natural Gas Hydrate Formation Based on Extremely Randomized Trees
Authors: He Wang
Published: May 2022

It is easy to form hydrates in the development of natural gas. It is of great significance to study the formation of prediction models to guide the safe production of oil and gas fields. Based on computer intelligence algorithms, a prediction model of natural gas hydrate formation based on Extremely randomized trees was established and compared with the BP Neral Network model. To objectively evaluate the predictive power of the model, an extensive database of more than 1000 hydrate formation conditions was established. The results show that the number of optimal decision trees for the Extremely randomized trees model is 6, and the decision tree depth is 32. The BP Neral Network model has a flat error distribution with a maximum error of 6.37%. The error distribution of the Extremely randomized trees model is abrupt, with a maximum error of 3.39%, with higher stability and accuracy. In terms of pure water, the BP Neral Network model performs well only in a small number of conditions due to over-fitting, but the Extremely randomized trees model can avoid over-fitting by using the large number theorem, showing a stronger advantage.
Correlation of KOH Concentration and Electrocatalytic Performance for Methanol Oxidation of Core-shell Au@Ag@Pd Nanoparticles with Different Surface Ag Contents
Authors: Miao Tingting , Liu Yingxia
Published: May 2022

This paper systematically studied the electrocatalytic performance of Au@Ag@Pd nanoparticles with different surface silver contents in methanol oxidation with different KOH concentrations using the core-shell structure of Au@Ag@Pd-f-AgmPd1-m nanoparticles (where f-AgmPd1-m is added to highlight surface Ag content) as the model. Under certain conditions, the increase of KOH concentration is beneficial to the catalytic activity of methanol. When the concentration of KOH is high, it has little influence on the catalytic activity of methanol.
Design of leakage prevention and diversion alarm system based on wireless control
Authors: Li Zhengdong , Wang Yulin , Wu Xuanyan , Jin Zhao , Lu Wen , Li Xiuling
Published: May 2022

To solve the leakage of contrast agents due to high pressure and fast speed of the high pressure injector, an intelligent anti-leakage system is designed. The pressure sensor MS5837 detects the pressure signal in real time and transmits the pressure signal to MSP430F5529. Once the micro controller detects that the pressure exceeds the threshold value, the leakage of the contrast agent is judged. The controller immediately starts the sound and light alarm and diversion switch function, and informs the medical staff of the clinic to deal with the leakage wound in time through the wireless transmission chip NRF24L01+. This system overcomes the disadvantages of previous mechanical design, such as easy loosening, no diversion. It adds diversion switching function and wireless communication module, which ensures that medical stuff can deal with the wound in the first time without radiation and reduce the leakage damage to the minimum. The results of animal experiments show that the intelligent diversion alarm system is stable, reliable and highly sensitive, which can effectively reduce the leakage of the contrast agents of the high pressure injector and relieve the pain of the patient.
Gyro Test Evaluation Based on Grey Clustering
Authors: Guan Wentao , Jiao Ronghui , Zhao Chen
Published: May 2022

Based on the test and evaluation of satellite control sub-systems, this article applies the gray clustering evaluation method in the gray system theory to the lack of objective quantitative standards in the current test and evaluation, and establishes the evaluation index system and evaluation model of the two-float gyro. The model is verified by using telemetry data and the evaluation conclusion of the gyro is got. The establishment of the model provides an objective and quantitative standard for the evaluation, and reduces the subjectivity and ambiguity in the evaluation. The model and method can be applied to other components of the control sub-system, and it has promotion significance for the test and evaluation of the entire control sub-system.
A Study on Parallel Test Approach for the Flash Burn-in Experiment in Laboratory
Authors: Wang Biao , Li Hao , Zhang Zijie
Published: May 2022

With the increasing number of lab burn-in samples, this paper proposes a parallel test approach for the problem that the single-device test board cannot meet the requirements of the JEDEC standard for the large number of samples with high efficiency. The designed FPGA control board independently separates 4 control SCAN signals, different SCAN chips perform read operations in sequence, and complete the operation in parallel. The experimental results show that, compared with the single-device test board, the MT test board can test 80 chips at the same time, which meets the requirements of the JEDEC standard, and reduces the requirement for hardware resources in the burn-in test, and improves test efficiency.
Research on Peak Current Predictive Control Algorithm for Boost Converter with Discrete Disturbance Observer
Authors: Zhang Dong , Zhang Yiming , Cui Longfei , Wang Mingxin
Published: May 2022

In this paper, a peak current predictive control algorithm based on discrete disturbance observer is proposed for BOOST converter. Compared with typical peak current predictive control algorithms, the proposed algorithm does not require additional a sensor to measure the input voltage in real time. The minimum beat tuning method of discrete disturbance observer is presented. It is proved that the inductance current tracks the reference value after two sampling cycles and eliminates input voltage disturbance after five sampling cycles. Simulation and experimental show the effectiveness of the proposed algorithm.
Electronics integration for the GE2/1 and ME0 GEM detector systems for the CMS phase-2 muon system upgrade
Authors: Butalla S. D. , Hohlmann M.
Published: May 2022

The Large Hadron Collider is currently undergoing its High Luminosity upgrade, which is set to increase the instantaneous luminosity by about a factor of five. Consequently, the Compact Muon Solenoid experiment is upgrading its muon spectrometer to cope with the increased muon flux in the forward region. The GE2/1 triple-gas electron multiplier detector, which has recently entered the mass production phase, and the ME0 triple-GEM detector system, which is in the late prototyping phase, are undergoing electronics integration. These proceedings briefly discuss the frontend electronics for the GE2/1 and ME0 detector systems, the electronics integration testing process, and the future plans for the frontend electronics of these two detector systems by the CMS GEM collaboration.
CMS phase-2 DAQ and timing hub prototyping results and perspectives
Authors: Amoiridis V. , Behrens U. , Bocci A. , Branson J. , Brummer P. , Cittolin S. , Da Silva-Gomes D. , Da Silva Almeida J. , Darlea G.-L. , Deldicque C. , Dobson M. , Gigi D. , Dzemaili N. , Gladki M. , Glege F. , Gomez-Ceballos G. , Gutic N. , Hansen M. , Hegeman J. , Moreno G.I. , James T.O. , Kishimoto C. , Leutgeb E. , Li W. , Meijers F. , Meschi E. , Morovic S. , Orsini L. , Papakrivopoulos I. , Paus C. , Peron K. , Petrucci A. , Pieri M. , Poupakis A. , Puljak E. , Rabady D. , Raychinov K. , Racz A. , Sakulin H. , Schwick C. , Simelevicius D. , Stahl A. , Troska J. , Vazquez-Velez C. , Zejdl P. , Zokaite V.
Published: May 2022

This paper describes recent progress on the design of the DAQ and Timing Hub, or DTH, an ATCA (Advanced Telecommunications Computing Architecture) hub board intended for the phase-2 upgrade of the CMS experiment. Prototyping was originally divided into multiple feature lines, spanning all different aspects of the DTH functionality. The second DTH prototype merges all R&D and prototyping lines into a single board, which is intended to be the production candidate. Emphasis is on the process and experience in going from the first to the second DTH prototype, which included a change of the chosen FPGA as well as the integration of a commercial networking solution.
Emittance preservation in advanced accelerators
Authors: Lindstrøm C.A. , Thévenet M.
Published: May 2022

Emittance is a beam quality that is vital for many future
applications of advanced accelerators, such as compact free-electron
lasers and linear colliders. In this paper, we review the challenges
of preserving the transverse emittance during acceleration, both
inside and outside accelerator stages. Sources of emittance growth
range from space charge and instabilities caused by transverse
wakefields, which can occur in any advanced accelerator scheme
regardless of medium or driver type, to sources more specific to
plasma accelerators, such as mismatching, misalignment, ion motion,
Coulomb scattering, chromaticity between stages, and more.
U.S. advanced and novel accelerator beam test facilities
Authors: Clarke C. , Esarey E. , Geddes C. , Hofstaetter G. , Hogan M.J. , Nagaitsev S. , Palmer M. , Piot P. , Power J. , Schroeder C. , Umstadter D. , Vafaei-Najafabadi N. , Valishev A. , Willingale L. , Yakimenko V.
Published: May 2022

Demonstrating the viability of Advanced Accelerator Concepts
(AAC) relies on experimental validation. Over the last three
decades, the U.S. has maintained a portfolio of advanced and novel
accelerator test facilities to support research critical to AAC. The
facilities have enabled pioneering developments in a wide variety of
beam and accelerator physics, including plasma-wakefield and
structure-wakefield acceleration. This paper provides an overview of
the current portfolio of U.S. facilities possessing charged particle
drive beams with high energies, on the order of tens of joules per
pulse, or drive lasers with high peak powers, on the order of a
petawatt, and are actively conducting AAC research.
Analysis and control of a running spring-mass model with a trunk based on virtual pendulum concept
Authors: Karagoz O K , Secer G , Ankarali M M , Saranli U
Published: May 2022

The spring-loaded inverted pendulum model has been one of the most studied conceptual models in the locomotion community. Even though it can adequately explain the center of mass trajectories of numerous legged animals, it remains insufficient in template-based control of complex robot platforms, being unable to capture additional dynamic characteristics of locomotion exhibited in additional degrees of freedom such as trunk pitch oscillations. In fact, analysis of trunk behavior during locomotion has been one of the motivations behind studying the virtual pivot point (VPP) concept, with biological inspiration and basis for both natural and synthetic systems with non-negligible trunk dynamics. This study first presents a comprehensive analysis of the VPP concept for planar running behaviors, followed by a systematic study of the existence and characteristics of periodic solutions. In particular, we investigate how periodic solutions depend on model control parameters and compare them based on stability and energetic cost. We then develop a feedback controller that can stabilize system dynamics around its periodic solutions and evaluate performance as compared to a previously introduced controller from the literature. We demonstrate the effectiveness of both controllers and find that the proposed control scheme creates larger basins of attraction with minor degradation in convergence speed. In conclusion, this study shows that the VPP concept, in conjunction with the proposed controller, could be beneficial in designing and controlling legged robots capable of running with non-trivial upper body dynamics. Our systematic analysis of periodic solutions arising from the use of the VPP concept is also an important step towards a more formal basis for comparisons of the VPP concept with bio-locomotion.
BayeshERG: a robust, reliable and interpretable deep learning model for predicting hERG channel blockers
Authors: Kim Hyunho , Park Minsu , Lee Ingoo , Nam Hojung
Published: May 2022

Unintended inhibition of the human ether-à-go-go-related gene (hERG) ion channel by small molecules leads to severe cardiotoxicity. Thus, hERG channel blockage is a significant concern in the development of new drugs. Several computational models have been developed to predict hERG channel blockage, including deep learning models; however, they lack robustness, reliability and interpretability. Here, we developed a graph-based Bayesian deep learning model for hERG channel blocker prediction, named BayeshERG, which has robust predictive power, high reliability and high resolution of interpretability. First, we applied transfer learning with 300 000 large data in initial pre-training to increase the predictive performance. Second, we implemented a Bayesian neural network with Monte Carlo dropout to calibrate the uncertainty of the prediction. Third, we utilized global multihead attentive pooling to augment the high resolution of structural interpretability for the hERG channel blockers and nonblockers. We conducted both internal and external validations for stringent evaluation; in particular, we benchmarked most of the publicly available hERG channel blocker prediction models. We showed that our proposed model outperformed predictive performance and uncertainty calibration performance. Furthermore, we found that our model learned to focus on the essential substructures of hERG channel blockers via an attention mechanism. Finally, we validated the prediction results of our model by conducting in vitro experiments and confirmed its high validity. In summary, BayeshERG could serve as a versatile tool for discovering hERG channel blockers and helping maximize the possibility of successful drug discovery. The data and source code are available at our GitHub repository (https://github.com/GIST-CSBL/BayeshERG).
Improving the nutritional value and bioactivity of soybean meal in solid-state fermentation using Bacillus strains newly isolated from the gut of the termite Termes propinquus
Authors: Nualkul Maneeploy , Yuangsoi Bundit , Hongoh Yuichi , Yamada Akinori , Deevong Pinsurang
Published: May 2022

The present study aimed to isolate and characterize proteolytic Bacillus spp. from termite guts to test the possibility of application for improving the nutritional value and bioactivity of fermented soybean meal (FSBM). Aerobic endospore-forming bacteria were isolated from the gut of the termite Termes propinquus. Ten isolates with high levels of soy milk degradation were selected and tested for extracellular enzyme production. Among them, two isolates, Tp-5 and Tp-7, exhibited all tested hydrolytic enzyme activities (cellulase, xylanase, pectinase, amylase, protease, lipase and phytase), weak alpha hemolytic and also antagonistic activities against fish pathogenic species of Aeromonas and Streptococcus. Both phylogenetic and biochemical analyses indicated that they were closely related to Bacillus amyloliquefaciens. During solid-state fermentation of SBM, Tp-5 and Tp-7 exhibited the highest protease activity (1127.2 and 1552.4 U g–1, respectively) at 36 h, and the resulting FSBMs showed a significant increase in crude protein content and free radical-scavenging ability (P < 0.05), as well as an improvement in the composition of amino acids, metabolites and other nutrients, while indigestible materials such as fiber, lignin and hemicellulose were decreased. The potential strains, especially Tp-7, improved the nutritional value of FSBM by their strong hydrolytic and antioxidant activities, together with reducing antinutritional components.
Long-Term Outcomes of the Excluded Rectum in Crohn’s Disease: A Multicenter International Study
Authors: Kassim Gassan , Yzet Clara , Nair Nilendra , Debebe Anketse , Rendon Alexa , Colombel Jean-Frédéric , Traboulsi Cindy , Rubin David T , Maroli Annalisa , Coppola Elisabetta , Carvello Michele M , Ben David Nadat , De Lucia Francesca , Sacchi Matteo , Danese Silvio , Spinelli Antonino , Hirdes Meike M C , ten Hove Joren , Oldenburg Bas , Cholapranee Aurada , Riter Maxine , Lukin Dana , Scherl Ellen , Eren Esen , Sultan Keith S , Axelrad Jordan , Sachar David B
Published: May 2022

Background

Many patients with Crohn’s disease (CD) require fecal diversion. To understand the long-term outcomes, we performed a multicenter review of the experience with retained excluded rectums.

Methods

We reviewed the medical records of all CD patients between 1990 and 2014 who had undergone diversionary surgery with retention of the excluded rectum for at least 6 months and who had at least 2 years of postoperative follow-up.

Results

From all the CD patients in the institutions’ databases, there were 197 who met all our inclusion criteria. A total of 92 (46.7%) of 197 patients ultimately underwent subsequent proctectomy, while 105 (53.3%) still had retained rectums at time of last follow-up. Among these 105 patients with retained rectums, 50 (47.6%) underwent reanastomosis, while the other 55 (52.4%) retained excluded rectums. Of these 55 patients whose rectums remained excluded, 20 (36.4%) were symptom-free, but the other 35 (63.6%) were symptomatic. Among the 50 patients who had been reconnected, 28 (56%) were symptom-free, while 22(44%) were symptomatic. From our entire cohort of 197 cases, 149 (75.6%) either ultimately lost their rectums or remained symptomatic with retained rectums, while only 28 (14.2%) of 197, and only 4 (5.9%) of 66 with initial perianal disease, were able to achieve reanastomosis without further problems. Four patients developed anorectal dysplasia or cancer.

Conclusions

In this multicenter cohort of patients with CD who had fecal diversion, fewer than 15%, and only 6% with perianal disease, achieved reanastomosis without experiencing disease persistence.
Similar forms have similar functions: dental microwear variability in Tasmanian devils
Authors: Reside Anna , Desantis Larisa R G
Published: May 2022

Dental microwear texture analysis (DMTA) is commonly used to assess the dietary ecology of modern and fossil taxa. In carnivorans, teeth with different functions record dietary behavior differently. Here, we assess DMTA variability along the tooth row of an extant carnivorous marsupial—the Tasmanian devil, Sarcophilus harrisii—which has multiple carnassial-like molars that may function and record diet similarly. We compared the complexity (Asfc), anisotropy (epLsar), and textural fill volume (Tfv) of the lower second, third, and fourth molars of Tasmanian devils to test the hypothesis that teeth with similar forms yield similar functions. Although third molars do have significantly higher epLsar values than fourth molars, all other DMTA attributes are indistinguishable from one another. These data suggest that teeth with comparable morphologies in the same taxon have similar functions and largely record diet similarly. In addition, we compared fossil and modern specimens of S. harrisii from Tasmania to assess dietary behavior over time. These analyses indicate that foods with similar textures have been consumed since the late Quaternary.
A Critique and Refinement of the Wakefieldian Concept of Disorder: An Improvement of the Harmful Dysfunction Analysis
Authors: Smith Emmanuel
Published: May 2022

One way in which bioethicists can benefit the medical community is by clarifying the concept of disorder. Since insurance companies refer to the DSM for whether a patient should receive assistance, one must consider the consequences of one’s concept of disorder for who should be provided with care. I offer a refinement of Jerome Wakefield’s hybrid concept of disorder, the harmful dysfunction analysis. I criticize both the factual component and the value component of Wakefield’s account and suggest how they might be improved. I propose that the factual component should be statistical variation analyzed in multilevel and chronological compilations of physiological data. I propose that the value component should prioritize the individual’s authority regarding the experience of suffering from a physiological condition. My account preserves the insight of using a factual and a value component while avoiding the problems that Wakefield’s original account faces.
Density exponent analysis: gravity-driven steepening of the density profiles of star-forming regions
Authors: Li Guang-Xing , Zhou Ji-Xuan
Published: May 2022

The evolution of molecular interstellar clouds is a complex, multiscale process. The power-law density exponent describes the steepness of density profiles, and it has been used to characterize the density structures of the clouds; yet its usage is usually limited to spherically symmetric systems. Importing the Level-Set Method, we develop a new formalism that generates robust maps of a generalized density exponent kρ at every location for complex density distributions. By applying it to high fidelity, high dynamical range map of the Perseus molecular cloud constructed using data from the Herschel and Planck satellites, we find that the density exponent exhibits a surprisingly wide range of variation (−3.5 ≲ kρ ≲ −0.5). Regions at later stages of gravitational collapse are associated with steeper density profiles. Inside a region, gas located in the vicinities of dense structures has very steep density profiles with kρ ≈ −3, which forms because of depletion. This density exponent analysis reveals diverse density structures, forming a coherent picture that gravitational collapse leads to a continued steepening of the density profile. We expect our method to be effective in studying other power law-like density structures, including granular materials and the large-scale structure of the Universe.
Discovery of a coherent, wave-like velocity pattern for the Radcliffe wave
Authors: Li Guang-Xing , Chen Bing-Qiu
Published: May 2022

Recent studies discovered that part of the Gould Belt belongs to a 2.7 kpc-long coherent, thin wave consisting of a chain of clouds, where a damped undulation pattern has been identified from the spatial arrangement of the clouds. We use the proper motions of young stellar objects anchored inside the clouds to study the kinematic structure of the Radcliffe wave in terms of vz, and identify a damped, wave-like pattern from the vz space, which we call ‘velocity undulation’. We propose a new formalism based on the ensemble empirical mode decomposition to determine the amplitude, period, and phase of the undulation pattern, and find that the spatial and velocity undulation share an almost identical spatial frequency of about 1.5 kpc, and both are damped when measured from one side to the other. Measured for the first cycle, they exhibit a phase difference of around 2π/3. The structure is oscillating around the mid-plane of the Milky Way disc with an amplitude of ${\sim}130\, \pm \, 20\, \rm pc$. The vertical extent of the Radcliffe wave exceeds the thickness of the molecular disc, suggesting that the undulation of the undulation signature might originate from a perturbation, e.g. the passage of a dwarf galaxy.
Organizational Practice and Neighborhood Context of Racial Inequality in Police Use-of-Force
Authors: Omori Marisa , Lautenschlager Rachel , Stoler Justin
Published: May 2022

Recent highly-publicized cases of police violence have raised broader discussions around understanding use-of-force as institutional racism. We explore how variation in police practices, including discretionary stops and targeting outdoor spaces, along with racialized understandings of crime and space, help explain use-of-force in neighborhoods. Using stop-and-frisk data from the New York City Police Department (NYPD) in Census tracts (N = 12675) between 2006 and 2012, we conduct a spatial analysis and estimate multilevel negative binomial regression models. We find relationships between use-of-force incidents and police organizational practices, where police use force more often in neighborhoods where they employ greater discretionary stops, and in neighborhoods where police conduct proportionally more indoor stops. Our findings also point to understanding stop-and-frisk as a spatial strategy concentrated largely in neighborhoods of color, where police use force more often in Black and Latinx neighborhoods above and beyond the racial disproportionately of individuals stopped. Police also use force more often in neighborhoods where they perceive more crime, even after accounting for the observed crime rate. We suggest that use-of-force by the NYPD is systematically produced through organizational practices paired with shared racialized understandings of crime and space that vary across neighborhoods.
Advantageous effect of pupil dilation on the quality of optical biometry axial length measurement in individuals with dense cataract
Authors: Bettach Emmanuel , Weill Yishay , Aronovitz Yocheved , Zadok David , Gelman Evegeny , Abulafia Adi
Published: May 2022

Purpose:

To evaluate the effect of pharmacologic pupil dilation on the quality of axial length (AL) measurement in patients with dense cataracts and previous low-quality AL measurements performed without dilation.

Setting:

Shaare-Zedek Medical Center, Jerusalem, Israel.

Design:

Retrospective case series.

Methods:

All participants underwent swept-source optical coherence tomographic (SS-OCT) biometry. Those with low-quality AL measurements due to dense cataract underwent an additional SS-OCT biometric evaluation after pupil dilation, and the AL measurement of the same eye was recorded.

Results:

2076 patients underwent SS-OCT during the study period, and 177 (8.52%) had low-quality AL measurements because of dense cataract. 79 (44.63%, mean age 72.53 ± 13.27 years, 43 females) of those 177 patients underwent repeat SS-OCT biometric imaging after pharmacologic pupil dilation, and formed the study group. After pupil dilation, high-quality AL measurements were successfully obtained in 60 (75.95%) of the 79 eyes. The mean SD of the AL measurements decreased significantly (P < .001), and the number of successful OCT scans per measurement increased significantly (P < .001) after pupil dilation. The mean difference of the AL before and after pupil dilation was 0.03 ± 0.07 mm (P < .001).

Conclusions:

Pharmacologic pupil dilation improved the quality of SS-OCT biometrically measured AL in patients with low-quality AL measurement due to dense cataract. These results could potentially improve postoperative refractive outcomes after cataract surgery and reduce the need of additional AL measurements by more complicated alternative means in this group.
Production of a Low-Cost, Off-the-Shelf, Decellularized Cartilage Xenograft for Tissue Regeneration
Authors: Vernice Nicholas A. , Berri Nabih , Bender Ryan J. , Dong Xue , Spector Jason A.
Published: May 2022

Background

Reconstruction of cartilaginous deformities is a well-established surgical challenge with high levels of unpredictability and complication. Because of the morbidity associated with autologous cartilage grafting, combined with its limited supply and the significant expense of commercially decellularized allografts, increasing efforts have sought to produce an acellular, nonimmunogenic cartilage xenograft. We have developed and validated a novel protocol for high throughput decellularization of ovine costal cartilage with immediate translational potential for preclinical investigation of novel strategies for cartilaginous reconstruction.

Methods

Floating ribs were isolated from freshly slaughtered rack of lamb and after cleaning, the ribs were either minced into 2-mm cubes or zested into 1-mm flakes. Tissue was then decellularized via a protocol consisting of 4 freeze/thaw cycles, digestion with trypsin, incubation in hyperosmolar and hypoosmolar salt solutions, with incubation in 1% Tween following both the hyperosmolar and hypoosmolar steps, a 48-hour incubation in nucleases, DNA elution via EDTA, and 2 terminal sterilization steps. Protocol success was evaluated via histologic analysis with hematoxylin and eosin, DAPI, and safranin-O staining, as well as DNA quantification.

Results

Histologic analysis of the decellularized tissue revealed a significant reduction in nuclei as evidenced by hematoxylin and eosin and DAPI staining (P < 0.01). Safranin-O staining demonstrated a depletion of glycosaminoglycan content in the decellularized cartilage but with preservation of tissue architecture. Unprocessed lamb cartilage contained 421 ± 60 ng DNA/mg of lyophilized tissue, whereas decellularized zested and minced costal cartilage contained 27 ± 2 ng DNA/mg lyophilized tissue (P < 0.0001) and 24 ± 2.3 ng DNA/mg lyophilized tissue (p < 0.0001), respectively, well below the threshold of 50 ng accepted as evidence of suitable decellularization. In comparison, commercial allograft cartilage contained 17 ± 5 ng DNA/mg of lyophilized tissue.

Conclusions

We have developed a novel protocol for the decellularization of xenogeneic cartilage graft. This structurally stable, low immunogenicity decellularized cartilage can be produced at low cost in large quantities for use in preclinical investigation.
The spread and burden of the COVID-19 pandemic in sub-Saharan Africa: comparison between predictions and actual data and lessons learned
Authors: Fokoua-Maxime Christophe Dongmo , Bellouche Yahia , Tchigui-Ariolle Dillonne Ngonpong , Tchato-Yann Tchana Loic , Choukem Simeon Pierre
Published: May 2022

Introduction

Sub-Saharan Africa (SSA) was predicted to be severely affected by the coronavirus disease 2019 (COVID-19) pandemic, but the actual data seem to have contradicted these forecasts. This study attempted to verify this observation by comparing predictions against actual data on the spread and burden of the COVID-19 pandemic in SSA.

Methods

Focused on the period from March 1stto September 30th, 2020, we compared (1) the predicted interval dates when each SSA country would report 1 000 and 10 000 COVID-19 cases, to the actual dates when these numbers were attained, as well as (2) the daily number of predicted versus actual COVID-19 cases.

Further, we calculated the case fatality ratio of the COVID-19 infection in SSA, and the correlation coefficient between the weekly average number of confirmed COVID-19 cases reported by each country and the weekly average stringency index of its anti-COVID-19 policy measures.

Results

84.61% (33) and 100% (39) of the 39 SSA countries for which predictions were made did not reach a total of 1 000 and 10 000 confirmed COVID-19 cases at the predicted interval dates. The daily number of confirmed COVID-19 cases was lower than the one projected for all SSA countries. The case fatality ratio of the COVID-19 infection in SSA was 3.42%. Among the 44 SSA countries for which the correlation could be estimated, it was negative for 17 (38.6 %) of them.

Conclusions

The natural characteristics of SSA and the public health measures implemented might partly explain that the actual data were lower than the predictions on the COVID-19 pandemic in SSA, but the low case ascertainment and the numerous asymptomatic cases did significantly influence this observation.
Compartment-Specific Measurement of Small Molecule Accumulation into Diderm Bacteria
Authors: Ongwae George M. , Lepori Irene , Chordia Mahendra D. , Dalesandro Brianna E. , Apostolos Alexis J. , Siegrist M. Sloan , Pires Marcos M.
Published: May 2022

Some of the most dangerous bacterial pathogens (Gram-negative and mycobacterial) deploy a formidable secondary membrane barrier to reduce the influx of exogenous molecules. For Gram-negative bacteria, this second exterior membrane is known as the outer membrane, while for the Gram-indeterminate Mycobacteria, it is known as the ‘myco’ membrane. Although different in composition, both the outer membrane and mycomembrane are key structures that restrict the passive permeation of small molecules into bacterial cells. While it is well-appreciated that such structures are principal determinants of small molecule permeation, it has proven to be challenging to assess this feature in a robust and quantitative way or in complex, infection-relevant settings. Herein, we describe the development of the Bacterial Chloro-Alkane Penetration Assay (BaCAPA), which employs the use of a genetically encoded protein called HaloTag, to measure the uptake and accumulation of molecules into model Gram-negative and mycobacterial species, Escherichia coli and Mycobacterium smegmatis, respectively, and into the human pathogen M. tuberculosis. Directing the localization of the HaloTag protein to either the cytoplasm or periplasm of bacteria enabled a compartmental analysis of permeation across individual cell membranes. Significantly, we also showed that BaCAPA can be used to analyze the permeation of molecules into host cell-internalized E. coli and M. tuberculosis, a critical capability for analyzing intracellular pathogens. Together, our results show that BaCAPA affords facile, compartment-specific measurement of permeability across four barriers: the host plasma and phagosomal membranes and the diderm bacterial cell envelope.
Testicular macrophages are recruited during a narrow time window by fetal Sertoli cells to promote organ-specific developmental functions
Authors: Gu Xiaowei , Heinrich Anna , DeFalco Tony
Published: May 2022

While macrophages are most commonly known for their roles in innate immunity, a growing body of evidence supports the idea that fetal-derived tissue-resident macrophages play developmental roles during organogenesis. In the testis, it has long been proposed that macrophages are important players in steroidogenesis and other testicular functions, but which macrophage populations are involved is unclear. We previously showed that macrophages play critical roles in fetal testis morphogenesis and reported the presence of 2 unique adult testicular macrophage populations, interstitial and peritubular. There has been some debate regarding the hematopoietic origins of testicular macrophages and whether distinct macrophage populations promote specific testicular functions. Here we have undertaken an extensive lineage-tracing study of mouse hematopoietic cells. We found that, while yolk-sac-derived macrophages comprise the earliest testicular macrophages, fetal hematopoietic stem cells (HSCs) give rise to monocytes that colonize the gonad during a narrow time window in mid-gestation, after which time HSCs no longer contribute to testicular macrophages. These long-lived monocytes, over the course of fetal and postnatal life, differentiate into testicular macrophages. Our data indicate that Sertoli cells, and not germ cells, are required for recruitment of immune cells and peritubular macrophage differentiation. Finally, we show that yolk-sac-derived macrophages and HSC-derived macrophages play distinct roles in testis cord morphogenesis, whereas interstitial macrophages promote adult Leydig cell proliferation and steroid production. Overall, our findings offer clarity regarding the origins of testicular macrophages and provide insight into the diversity of their tissue-specific developmental roles.
Generalisation of early learned tutor song preferences in female zebra finches (Taeniopygia guttata)
Authors: Wei Jing , Liu Quanxiao , Riebel Katharina
Published: May 2022

Song learning is a prime example for a culturally transmitted mating signal. Local or individual song variants are socially learned early in life and adults sing and prefer these songs. An unresolved issue in this context is the question of how learned preferences for specific variants generalise to songs sufficiently similar to the original model. Here we asked whether female zebra finches would generalise early learned song preferences along a similarity gradient based on syllables sharing between test and tutor songs. For each female, this gradient consisted of their tutor’s (father’s) song (F), two variants of unfamiliar songs edited to share 2/3 (F2/3) and 1/3 (F1/3) of syllables with father’s song and an unfamiliar song (UF). Females’ preferences were measured in a 4-way operant choice arena where the birds could perch on different operant perches to trigger playbacks of the four different songs. Number and duration of perch visits were positively associated with the number of syllables that the assigned stimuli shared with fathers’ songs. These results suggest that female zebra finches generalise early learned song preferences to songs sharing syllables (and/or voice characteristics) with songs learned early in life.
A new microbiological weapon against lepidopteran pests
Authors: Martemyanov Vyacheslav V. , Akhanaev Yuriy B. , Belousova Irina A. , Pavlusin Sergey V. , Yakimova Maria E. , Kharlamova Daria D. , Ageev Alexander A. , Golovina Anna N. , Astapenko Sergey A. , Kolosov Alexey V. , Ananko Grigory G. , Taranov Oleg S. , Shvalov Alexander N. , Bodnev Sergey A. , Ershov Nikita I. , Grushevaya Inna V. , Tymofeev Maxim A. , Tokarev Yuri S.
Published: May 2022

Nowadays researchers provide more and more evidence that it is necessary to develop an ecologically friendly approach to pest control. This is reflected in a sharp increase in the value of the biological insecticide market in recent decades. In our study, we found a virus strain belonging to the genus Cypovirus (Reoviridae); the strain was isolated from Dendrolimus sibiricus: that possesses attractive features as a candidate for mass production of biological agents for lepidopteran-pest control. We describe morphological, molecular, and ecological features of the new Cypovirus strain. This strain was found to be highly virulent to D. sibiricus (half-lethal dose is 68 occlusion bodies per second-instar larva) and to have a relatively wide host range (infects representatives of five families of Lepidoptera: Erebidae, Sphingidae, Pieridae, Noctuidae, and Lasiocampidae). The virus strain showed a strong interaction with a nontoxic adjuvant (optical brightener), which decreased the lethal dose for both main and alternative hosts, decreased lethal time, and may expand the host range. Moreover, we demonstrated that the insecticidal features were preserved after passaging through the most economically suitable host. By providing strong arguments for possible usefulness of this strain in pest control, we call on virologists, pest control specialists and molecular biologists to give more attention to the Cypovirus genus, which may lead to new insights in the field of pest control research and may provide significant advantages to compare with baculoviruses and Bacillus thuringiensis products which are nowadays main source of bioinsecticides.

Significance statement

Within this article we are describing unique set of features of newly discovered cypovirus strain which possess by significant premises for modern biological insecticides requirements: high potency, universality, true regulating effect, flexible production (possibility to choose host species for production), interaction with enhancing adjuvants, ecologically friendly. Basing on genome alignment we suggest that increasing of host range of new strain is the sequence of evolutionary event which was occurred after coinfection of different CPV species within same host. This finding open new perspective to consider CPVs as perspective agent of biocontrol products.