bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast dynamic voltage security margin estimation: concept and development
Authors: Hagmar Hannes , Eriksson Robert , Tuan Le Anh
Published: April 2020

This study develops a machine learning‐based method for a fast estimation of the dynamic voltage security margin (DVSM). The DVSM can incorporate the dynamic system response following a disturbance and it generally provides a better measure of security than the more commonly used static voltage security margin (VSM). Using the concept of transient P ‐ V curves, this study first establishes and visualises the circumstances when the DVSM is to prefer the static VSM. To overcome the computational difficulties in estimating the DVSM, this study proposes a method based on training two separate neural networks on a data set composed of combinations of different operating conditions and contingency scenarios generated using time‐domain simulations. The trained neural networks are used to improve the search algorithm and significantly increase the computational efficiency in estimating the DVSM. The machine learning‐based approach is thus applied to support the estimation of the DVSM, while the actual margin is validated using time‐domain simulations. The proposed method was tested on the Nordic32 test system and the number of time‐domain simulations was possible to reduce with ∼70%, allowing system operators to perform the estimations in near real‐time.
Controlling DC microgrids in communities, buildings and data centers
Authors: Kolluri Ramachandra Rao , Mareels Iven , de Hoog Julian
Published: April 2020

Microgrid technology is poised to transform the electricity industry. In the context of commercial/domestic buildings and data centers, where most loads are native direct current, DC microgrids are in fact a natural choice. Voltage stability and current/power‐sharing between sources within a DC microgrid have been studied extensively in recent years. DC voltage droop control is known to have its drawbacks in that current or power‐sharing is relatively poor. To eliminate this drawback, some have proposed to add a communication‐based consensus control in addition to the primary voltage droop control loop. The current sharing performance is improved, however, the voltage deviation inherent in droop control requires a further, slower control to achieve voltage quality control. To overcome this complication, and reduction in response time, a low latency communication‐based control technique that achieves proportional current sharing without significant voltage deviations is proposed in this work. The stability of the proposed control technique is compared to state‐of‐the‐art using eigenvalue and transient analyses. The negative impact of communication delays on proposed control is discussed in detail.
The minimal time function associated with a collection of sets
Authors: Nguyen Luong V. , Qin Xiaolong
Published: April 2020

We define the minimal time function associated with a collection of sets which is motivated by the optimal time problem for nonconvex constant dynamics. We first provide various basic properties of this new function: lower semicontinuity, principle of optimality, convexity, Lipschitz continuity, among others. We also compute and estimate proximal, Fréchet and limiting subdifferentials of the new function at points inside the target set as well as at points outside the target. An application to location problems is also given.
Particle Entrainment and Deposition Scenario in Sublayer Region of Variable Area Conduit
Authors: Jassim Esam
Published: April 2020

The study presents the particle deposition and aggregation phenomena by introducing new parameter called Particle Deposition Number PDN, defined as the ratio of the particle instantaneous velocity to its capturing value. The particle capture or rebound fate will decide from knowing such number. The study employed new scheme of particle deposition in the sublayer region which includes balancing of four forces. Moreover, the bouncing model is also considered for particle fate decision. The study examines the variation of particle velocity at varying area tube and the critical velocity in which particle will tend to stick if its velocity is lower than the threshold limit. The results show that threshold velocity is exponentially decreased with the increment in the particle size. Capturing of particles is shown to be enhanced as the conduit converges due to increasing in the PDN. The analysis of the deposition also investigates the impact of the particle size on the PDN. At low flow velocity, the NDP has V-shaped trend as particle size increases. However, veering toward constant PDN value has occurred as the flow velocity augmented. Finally, small sized particles experience rebound due to the prevailing of the particle impact energy over the adhesion energy before impacting with the surface. The dissipation in the particle energy during impaction causes large sized particle to loose greater amount of energy compare to small sized one, resulting in domination of the adhesion part, which leads to deposition on the surface.
Seroprevalence and risk factors of Toxoplasma gondii infection in primary school children in Henan province, central China
Authors: Wang Shuai , Yao Zhijun , Li Haoran , Li Pengju , Wang Dong , Zhang Haizhu , Xie Qing , Zhang Zhenchao , Li Xiangrui
Published: April 2020

Toxoplasma gondii is an obligate intracellular protozoan parasite with global distribution. However, data on T. gondii infection among children in primary school in Henan province, central China were lacking. In this study, 2451 serum samples of primary school children in this province were collected from September 2015 to October 2018 and evaluated for T. gondii antibodies using an enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence was 9.51% (233/2451), of which 7.59% (186/2451) showed IgG positivity, 0.73% (18/2451) IgM and 1.18% (29/2451) both. The main risk factors related to T. gondii infections were the age of children, residence area, contact with cats, and exposure to soil. Moreover, hand washing before eating was considered a protective factor. Seroprevalence of T. gondii infection among the study population was common, emphasizing the need to prevent and control this infection. This is the first report of T. gondii seroprevalence in primary school children in Henan province, central China.
Lipotransfer führt zu Verbesserung von Schluck- und Artikulationsstörungen nach mikrochirurgischer Zungenrekonstruktion – ein Fallbericht
Authors: Cai Aijia , Iro Heinrich , Horch Raymund E
Published: April 2020

Nach mikrochirurgischer Zungenrekonstruktion durch freie Lappenplastiken kommt es häufig zu einer Atrophie der Zunge, was zu funktionellen Einschränkungen wie Artikulationsstörungen oder Dysphagie führt. Eine Volumenaugmentation mittels Lipotransfer könnte dieser Problematik entgegenwirken. Wir beschreiben einen Fallbericht über wiederholte Lipotransfers in eine atrophierte rekonstruierte Zunge. Ein 66-jähriger Patient hatte bei Plattenepithelkarzinom der Zunge eine Hemiglossektomie und die anschließende Zungenrekonstruktion mittels freier Radialislappenplastik erhalten. Nach Atrophie der rekonstruierten Zunge führten wir wiederholte Lipotransfer-Sitzungen zur Augmentation des atrophierten Gewebes durch. Insgesamt führten drei Lipotransfer-Sitzungen zu einem zufriedenstellenden Ergebnis. Durch die Augmentation der Zunge konnte eine Verbesserung der ursprünglichen Schluck- und Artikulationsstörungen erzielt werden.

Dies ist nach unserem Kenntnisstand der erste Fallbericht über Augmentation eines Lappens in der Mundhöhle mittels Lipotransfer, welches ein nützliches Mittel bei der Zungenrekonstruktion darstellt. Wir empfehlen daher die Volumenaugmentation mittels Lipotransfer als zusätzliches Hilfsmittel zur Verbesserung des funktionellen Status bei der Zungenrekonstruktion.
Aktueller Algorithmus zur Diagnostik und Therapie des Brustimplantat-assoziierten anaplastischen großzelligen Lymphoms
Authors: Moellhoff Nicholas , Frank Konstantin , Wiggenhauser Paul S. , Schenck Thilo L. , Mayr Doris , Giunta Riccardo E.
Published: April 2020

Bei elektiven Operationen gilt es ein höchstes Maß an Sicherheit zu gewährleisten und Patienten ausführlich über die mit dem Eingriff verbundenen Risiken zu informieren. Insbesondere bei ästhetischen Eingriffen in der Plastischen Chirurgie ist es die Pflicht des Chirurgen eine ganzheitliche und umfassende Aufklärung auch über mögliche Langzeitfolgen durchzuführen. In den letzten Jahren steht die Verwendung von Brustimplantaten zur ästhetischen Brustaugmentation oder zur Brustrekonstruktion nach Tumorresektion zunehmend im Fokus der Öffentlichkeit, nachdem sich weltweit die Fallzahlen von seltenen Brustimplantat-assoziierten Krankheitsbildern häufen und die Ursachen nicht vollständig geklärt sind. Das breast implant-associated anaplastic large cell lymphoma (engl. BIA-ALCL) wurde 2016 von der Weltgesundheitsorganisation als lymphatische Neoplasie klassifiziert.

Mittlerweile wurden weltweit knapp 800 Fälle, die vor allem texturierte Implantate betreffen, dokumentiert. Die maligne Erkrankung führt zu einer Verunsicherung von Patientinnen mit Implantaten. Daher ist es eine zentrale Aufgabe der Plastischen Chirurgen dieses seltene Krankheitsbild zu verstehen, es frühzeitig zu erkennen und klare Handlungsempfehlungen zu formulieren. Das vorliegende Manuskript soll den aktuellen Stand zum Vorgehen im Hinblick auf Diagnostik und Therapie des BIA-ALCL zusammenfassen.
Wie gut werden Patientinnen auf Internetseiten von deutschen universitären Brustzentren über die Möglichkeiten der Brustrekonstruktion informiert?
Authors: Keck Maike , Bergmann Philipp Alexander , Deindl Philipp , Wittig Klaus Stephan , Lohmeyer Jörn Andreas
Published: April 2020

Einleitung Das Internet hat sich in den letzten Jahrzehnten zu einer der wichtigsten Informationsquellen für Patienten entwickelt. Wie gut sind die Möglichkeiten, sich im Internet über eine Brustrekonstruktion zu informieren? Wie präsent ist die Plastische Chirurgie mit ihrem Spektrum an modernen rekonstruktiven Möglichkeiten in Deutschland?

Methoden Insgesamt wurden 35 Homepages der universitären Brustzentren in Deutschland bezüglich Erwähnung einer Zusammenarbeit mit einem Plastischen Chirurgen bzw. einer Abteilung für Plastische Chirurgie und deren Verlinkung, Angaben bezüglich rekonstruktiver Möglichkeiten wie der Implantatrekonstruktion, Eigengeweberekonstruktion mit gestielten und freien Lappenplastiken sowie Lipofilling analysiert.

Ergebnisse Auf 49 % der Homepages wird ein Plastischer Chirurg bzw. eine kooperierende Abteilung erwähnt, 20 % beinhalten eine direkte Verlinkung. Auf 91 % der Seiten wird die Möglichkeit einer Brustrekonstruktion beschrieben, auf 80 % der Webseiten die Verwendung von Eigengewebe im Allgemeinen. In 51 % der Fälle wird ein freier Gewebetransfer erwähnt, wobei nur 23 % die Verfahren wie DIEP-Lappenplastik, TMG oder I-GAP genauer beschreiben. Nur zwei Zentren verwenden hierzu detaillierte Abbildungen. Bei sechs Internetauftritten (17 %) wird lediglich eine Rekonstruktion mit gestieltem TRAM Lappen beschrieben. Eine Rekonstruktion mit Silikonimplantat wird auf 71 % der Websites erwähnt. Die Möglichkeit eines Lipofillings wird in 31 % erörtert.

Diskussion In etwa der Hälfe der Webauftritte universitärer Brustzentren ist keine Zusammenarbeit mit einem Plastischen Chirurgen ersichtlich. Die Informationen über den freien Gewebetransfer zur Brustrekonstruktion weisen große Lücken auf.
Large Fibre Neuropathy: Part of Fibromyalgia or Coexisting
Entity?
Authors: Gezginaslan Ömer , Sürmeli Reyhan , Atalay Sevgi Gümüş
Published: April 2020

Zielsetzung Ziel dieser Studie ist es, die Inzidenz von Large Fibre
Neuropathy (LFN) bei Fibromyalgie (FM) -Patienten mit peripheren
Neuropathie-Beschwerden zu untersuchen und den Einfluss von LFN und FM auf
Schmerzen, Lebensqualität, Schlafqualität, Behinderung, und
depressive Symptome.

Methoden Zwischen Juni 2018 und Februar 2019 wurden insgesamt 104
Patienten (67 Frauen, 37 Männer; Durchschnittsalter: 52,21±9,53
Jahre; Spanne 31–74 Jahre) mit der Diagnose FM in die Studie
eingeschlossen. Die Patienten wurden in 2 Gruppen eingeteilt: Gruppe 1,
einschließlich Patienten mit Polyneuropathie (PNP) (n=48) und
Gruppe 2, einschließlich Nicht-PNP-Patienten (n=54). Gruppe 1
wurde auch weiter in 2 Untergruppen als sensorische PNP (n=28) und
sensomotorische PNP (n=20) unterteilt. Alle Patienten wurden anhand der
Visual Analog Scale (VAS), des Fibromyalgia Impact Questionnaire (FIQ), des
Short Form-36 (SF-36), des Pittsburgh Sleep Quality Index (PSQI) und des Beck
Depression Inventory (BDI) bewertet.

Ergebnisse Es gab keinen statistisch signifikanten Unterschied in den
demografischen Merkmalen zwischen den Gruppen (p>0,05). Es gab einen
statistisch signifikanten Unterschied in den VAS-, SF-36-, BDI-, FIQ- und
PSQI-Werten zwischen Gruppe 1 und Gruppe 2 (p<0,05). Es gab keinen
statistisch signifikanten Unterschied in den VAS-, SF-36-, BDI-, FIQ- und
PSQI-Werten zwischen den sensorischen und sensomotorischen PNP-Gruppen
(p>0,05).

Schlussfolgerungen Unsere Studienergebnisse zeigen, dass FM mit LFN die
Schmerzen, die Lebensqualität, die Schlafqualität, die
Behinderung und die depressiven Symptome negativ beeinflusst, gegenüber
denjenigen ohne LFN, was auf die Bedeutung des Neuropathiemanagements bei
FM-Patienten hinweist.
Trends of Obese and Morbidly Obese Patients in Same-Day Bilateral Total Knee Arthroplasty from 2009 to 2016
Authors: Remily Ethan A. , Wilkie Wayne A. , Mohamed Nequesha S. , Pastore Mark , Viola Anthony , Cho Abraham H. , Nace James , Delanois Ronald E.
Published: April 2020

As obesity in the United States increases, the proportion of obese and morbidly obese patients undergoing same-day bilateral total knee arthroplasty (sd-BTKA) remains unknown. Therefore, this study analyzed: (1) incidence, (2) patient demographics, (3) patient course, and (4) patient outcomes in obese and morbidly obese patients undergoing sd-BTKA in the United States from 2009 to 2016. The National Inpatient Sample was queried for all sd-BTKA patients from 2009 to 2016, yielding 39,901 obese and 20,394 morbidly obese patients. Analyzed variables included overall incidence, age, length of stay (LOS), sex, race, payer, Charlson comorbidity index (CCI) status, disposition, complications, location/teaching status, region of hospital, costs, and charges. Categorical variables were evaluated with chi-square analysis, while continuous variables were analyzed by Student's t-tests. Overall, the number of sd-BTKAs decreased over the study period, although the proportion of both obese and morbidly obese patients increased (p < 0.001 for all). The most common CCI status, 3 + , decreased in proportion for both groups (p < 0.001 for all). Hospital costs decreased and charges increased for both groups (p < 0.001 for all). Mean LOS decreased and patients were most commonly discharged to skilled nursing facilities, although these proportions decreased (p < 0.001 for all). Respiratory failures (p < 0.001 for all) increased for both groups, while proportion of deep vein thromboses and hematomas/seromas (p < 0.001 for all) increased for obese patients and proportion of pulmonary emboli (p < 0.001) increased for morbidly obese patients. The results of this study appear to portray improving optimization and patient selection of higher body mass index (BMI) individuals undergoing this procedure. More information is needed comparing the safety of the sd-BTKA across patients of all BMI groups.
Early Neuromuscular Blockade in Children with Pediatric Acute Respiratory Distress Syndrome
Authors: Chandra Surabhi , Goel Sahil , Dawra Ritika
Published: April 2020

Pediatric acute respiratory distress syndrome (PARDS) is a challenging problem with high mortality. Role of neuromuscular blockade in the management of ARDS to date has been controversial, and this study was done to study the role of neuromuscular blockade in children having PARDS and development of associated complications, if any. This was a prospective, case–control study conducted in the pediatric intensive care unit (PICU) of a tertiary care teaching hospital, over a period of 24 months. Patients of age 1 to 18 years who presented with or developed PARDS during their course of hospitalization were included after written informed consent was obtained from their parents and/or guardians. Patients with PARDS requiring invasive mechanical ventilation were partitioned into a case group and a control group. Case group patients were sedated and paralyzed using midazolam (1 µg/kg/min) and vecuronium (1 µg/kg/min), respectively, along with institution of definitive management. Control group patients were given definitive and supportive therapy, but no neuromuscular blocking agents (NMBAs). All patients were followed up for signs and symptoms of myopathy or neuropathy during the entire duration of hospital stay and up to 3 months after discharge. During the study period, 613 patients were admitted to the PICU of which 91 patients qualified as having PARDS. Sepsis was the main etiology in 67 of the 91 patients (73.6%) with PARDS. Fifty-nine patients were included in the study, of which 29 patients were included in the case group and 30 patients were included in the control group. Among the 29 case group patients, 25 patients (86.2%) were successfully extubated. Four patients from the case group expired, while 14 out of 30 control group patients (46.7%) expired. Hypotension was present in 26 case group patients (89.6%), of which all showed resolution within 48 hours of definitive treatment. The mean time to resolution of hypotension was 41.6 hours (standard deviation [SD]: 5.759; range: 24–48) for case group patients, significantly lower (p < 0.0001) than the mean time to resolution of 103 hours (SD: 18.995; range: 90–126) for the 10 control group patients with hypotension that survived. Mean oxygenation index (OI) following 48 hours of vecuronium therapy was significantly lower (p < 0.0001; 95% confidence interval: 5.9129–9.9671) than mean OI at admission for case group patients. None of the patients receiving vecuronium exhibited neuromuscular deficit during their hospital stay, at time of discharge, or at follow-up evaluation up to 3 months after discharge. In this study, pediatric cases diagnosed with PARDS and managed with mechanical ventilation and vecuronium therapy had improved mean OI following 48 hours of NMBA therapy and a lower mortality when compared with matched control group patients. Incidence of NMBA-related weakness was not commonly observed in these patients.
Cementless Fixation for Total Knee Arthroplasty in Various Patient Populations: A Literature Review
Authors: Salem Hytham S. , Tarazi John M. , Ehiorobo Joseph O. , Marchand Kevin B. , Mathew Kevin K. , Sodhi Nipun , Mont Michael A.
Published: April 2020

The number of total knee arthroplasties (TKAs) performed in the United States has increased considerably in recent years, with a major contribution from younger patients. Maximizing survivorship of these implants has always been a point of emphasis. Early TKA designs with cementless fixation were associated with high rates of complications and implant failures. However, recent advances in cementless designs have shown excellent results. The decision to use cemented or cementless fixation for patients undergoing TKA is typically based on the surgeon's experience and preference. However, several patient characteristics must also be taken into account. The purpose of this review was to describe the clinical outcomes of studies in which a cementless TKA system was utilized for patients who (1) were less than 60 years of age, (2) were greater than 75 years of age, (3) were obese, (4) had rheumatoid arthritis, and (5) had osteonecrosis of the knee. Based on the studies included in this review, it appears that cementless fixation is a viable option for patients who have all of the above demographics.
Development of a rapid cooling atomizing method and production of high-Bs nanocrystalline powders containing large-sized particles
Authors: Uji K. , Tomita T. , Yoshida K. , Takahashi T. , Kuwata H.
Published: April 2020

We attempted to produce nanocrystalline soft magnetic powders with a high saturation magnetic flux density (Bs) and containing large-sized particles using a modified water atomization system named “HPWA/YK.” Almost fully amorphous powders containing particles with median diameters of 15 μm and composed of Fe83.3Si4B8P4Cu0.7 were obtained. These results indicate that HPWA/YK reached a higher quenching rate than conventional water atomization systems. The powder circularity reached a value of 0.78 by changing the ratio of the gas to water pressure; moreover, after annealing at 713 K, the powders presented good magnetic properties (Bs = 1.66 T; Hc = 155 A/m).
Nanoerythrosome-functionalized biohybrid microswimmers
Authors: Buss Nicole , Yasa Oncay , Alapan Yunus , Akolpoglu Mukrime Birgul , Sitti Metin
Published: April 2020

Biohybrid microswimmers, which are realized through the integration of motile microscopic organisms with artificial cargo carriers, have a significant potential to revolutionize autonomous targeted cargo delivery applications in medicine. Nonetheless, there are many open challenges, such as motility performance and immunogenicity of the biological segment of the microswimmers, which should be overcome before their successful transition to the clinic. Here, we present the design and characterization of a biohybrid microswimmer, which is composed of a genetically engineered peritrichously flagellated Escherichia coli species integrated with red blood cell-derived nanoliposomes, also known as nanoerythrosomes. Initially, we demonstrated nanoerythrosome fabrication using the cell extrusion technique and characterization of their size and functional cell membrane proteins with dynamic light scattering and flow cytometry analyses, respectively. Then, we showed the construction of biohybrid microswimmers through the conjugation of streptavidin-modified bacteria with biotin-modified nanoerythrosomes by using non-covalent streptavidin interaction. Finally, we investigated the motility performance of the nanoerythrosome-functionalized biohybrid microswimmers and compared it with the free-swimming bacteria. The microswimmer design approach presented here could lead to the fabrication of personalized biohybrid microswimmers from patients' own cells with high fabrication efficiencies and motility performances.
Separatrices in the Hamilton–Jacobi formalism of inflaton models
Authors: Álvarez Gabriel , Martínez Alonso Luis , Medina Elena , Vázquez Juan Luis
Published: April 2020

We consider separatrix solutions of the differential equations for inflaton models with a single scalar field in a zero-curvature Friedmann–Lemaître–Robertson–Walker universe. The existence and properties of separatrices are investigated in the framework of the Hamilton–Jacobi formalism, where the main quantity is the Hubble parameter considered as a function of the inflaton field. A wide class of inflaton models that have separatrix solutions (and include many of the most physically relevant potentials) is introduced, and the properties of the corresponding separatrices are investigated, in particular, asymptotic inflationary stages, leading approximations to the separatrices, and full asymptotic expansions thereof. We also prove an optimal growth criterion for potentials that do not have separatrices.
A theoretical model for suppression effect of single-surface multipactor on dielectric by external DC magnetic field
Authors: Sun Yanzi , Zhang Ziyi , Liu Zhen , Cui Wanzhao , Chang Chao
Published: April 2020

This paper proposes a theoretical model for the single-surface multipactor on a dielectric. We consider the combined effects of the normal cumulative electric field, the normal and tangential radio frequency (RF) electric fields, as well as the tangential external direct current (DC) magnetic field and study the suppression effect of the tangential external DC magnetic field on the resonant multipactor. Kinetic properties of the electron and the resonant multipactor condition with no tangential external DC magnetic field are derived by analytical calculations. The flight time of the electron is analyzed profoundly by considering different values of the electron’s initial energy, the amplitude ratio between the normal cumulative electric field and the normal RF electric field, and the tangential external DC magnetic field. Our results demonstrate that the tangential external DC magnetic field can decrease the flight time, and hence, the resonant multipactor can be suppressed or mitigated effectively by the tangential external DC magnetic field. The flight time of the electron shows a decreasing trend as the electron’s initial energy increases, and the amplitude ratio between the normal cumulative electric field and the normal RF electric field decreases. The suppression effect of the tangential external DC magnetic field on the resonant multipactor can be much stronger when the amplitude ratio between the normal cumulative electric field and the normal RF electric field becomes larger. The resonant multipactor suppressing is also relevant to the amplitude ratio and the initial phase difference between the tangential and normal RF electric fields.
Oscillation regimes and mechanisms in the vortex-induced vibrations of three circular cylinders with equilateral-triangular arrangements
Authors: Chen Weilin , Ji Chunning , Xu Dong , Zhang Zhimeng
Published: April 2020

This paper presents the oscillation regimes and underlying mechanisms of the vortex-induced vibrations (VIVs) of three separated and elastically mounted circular cylinders aligned in equilateral-triangular arrangements with the Reynolds number Re = 100, the mass ratio m* = 2.0, the spacing ratio L* = 2.0–5.0, and the reduced velocity Ur = 0.0–15.0. Three cylinders, with one placed upstream and the other two placed side-by-side downstream, are constrained to vibrate only in the transverse direction. In the examined L* range, the responses of the three cylinders can be divided into five regimes. The features of the vibration amplitudes, vibration frequencies, displacement phase lags, and mean position shifts in each regime are explored in detail. The mechanisms of several important issues regarding the VIV are elucidated. We found that (1) the roles of the separation, reattachment, detachment, merging, and rolling-up of the shear layer in sustaining the cylinder vibrations differ in each regime. (2) The significant increase in the amplitudes of the two downstream cylinders in regime II stems from the vorticity supply from the upstream cylinder. (3) The low vibration frequency of the upstream cylinder in an anti-phase flow is closely related to the presence of a slightly asymmetric wake of the downstream cylinders. (4) The large-amplitude vibrations of the two downstream cylinders in regime V at L* = 2.0 is maintained by the shear layer reattachment of the upstream cylinder and the pushing effects between the two downstream cylinders. (5) Finally, the different incoming flow velocities for the upstream and downstream cylinders may cause different vibration frequencies.
Fluidics in an emptying bottle during breaking and making of interacting interfaces
Authors: Rohilla Lokesh , Das Arup Kumar
Published: April 2020

An experimental effort has been reported in the present study analyzing the fluidics during the emptying of a bottle. The viscosity of the containing liquid and the orientation of the bottle while emptying are varied to obtain different emptying modes. Stages during the emptying of a vertical upended and an inclined bottle have been demarcated based on prompt flow features. Fluidic phenomena such as formation and pinch-off of an encapsulated bubble, ejector jet, flooding, and stratification have been observed in a vertically upended bottle. The rise velocity, collapse dynamics, and growth rate of the bubble at the bottle mouth are affected by the angle of inclination and mainly viscosity of the emptying liquid. Two distinct bottle emptying modes have been identified in one of which the discharge rate is increased due to a high-frequency pinch-off of air bubbles inside the bottle and in another mode due to an increase in the volume of the pinched-off bubble at a comparatively lower frequency. The interaction of dominant forces during the emptying process has been established by quantifying Reynolds number, Weber number, and Bond number. For all emptying liquids, bottle emptying time reduces linearly up to a critical angle of inclination, θcrit ∼ 20°, and further follows an asymptote. We hypothesize that the transition between the linear regime and the asymptotic regime is due to the saturation of the voidage of the air at the cylindrical section of the bottle mouth. Furthermore, the geometry of the bottle also facilitates the growth rate of the bubble inside the bottle at θcrit.
Aminoacyl-tRNA synthetase inhibition activates a pathway that branches from the canonical amino acid response in mammalian cells
Authors: Kim Yeonjin , Sundrud Mark S. , Zhou Changqian , Edenius Maja , Zocco Davide , Powers Kristen , Zhang Miao , Mazitschek Ralph , Rao Anjana , Yeo Chang-Yeol , Noss Erika H. , Brenner Michael B. , Whitman Malcolm , Keller Tracy L.
Published: April 2020

Signaling pathways that sense amino acid abundance are integral to tissue homeostasis and cellular defense. Our laboratory has previously shown that halofuginone (HF) inhibits the prolyl-tRNA synthetase catalytic activity of glutamyl-prolyl-tRNA synthetase (EPRS), thereby activating the amino acid response (AAR). We now show that HF treatment selectively inhibits inflammatory responses in diverse cell types and that these therapeutic benefits occur in cells that lack GCN2, the signature effector of the AAR. Depletion of arginine, histidine, or lysine from cultured fibroblast-like synoviocytes recapitulates key aspects of HF treatment, without utilizing GCN2 or mammalian target of rapamycin complex 1 pathway signaling. Like HF, the threonyl-tRNA synthetase inhibitor borrelidin suppresses the induction of tissue remodeling and inflammatory mediators in cytokine-stimulated fibroblast-like synoviocytes without GCN2, but both aminoacyl-tRNA synthetase (aaRS) inhibitors are sensitive to the removal of GCN1. GCN1, an upstream component of the AAR pathway, binds to ribosomes and is required for GCN2 activation. These observations indicate that aaRS inhibitors, like HF, can modulate inflammatory response without the AAR/GCN2 signaling cassette, and that GCN1 has a role that is distinct from its activation of GCN2. We propose that GCN1 participates in a previously unrecognized amino acid sensor pathway that branches from the canonical AAR.
Depth-dependent soil mixing persists across climate zones
Authors: Gray Harrison J. , Keen-Zebert Amanda , Furbish David J. , Tucker Gregory E. , Mahan Shannon A.
Published: April 2020

Significance

Soil mixing occurs when sediment and organic matter are moved by biotic processes (burrowing mammals and invertebrates, root growth, and decay) and abiotic processes (movement of water and granular creep). Soil mixing plays a key role in carbon storage, nutrient and contaminant dispersion, and hillslope sediment transport, yet we lack quantitative information about soil mixing and its variation with depth in a soil profile. Here we present evidence showing that soil mixing systematically varies with depth in the soil. We also find that soils appear to be mixed similarly across climate zones, suggesting that soil mixing operates in a similar way over a range of different environments.
Latinos’ deportation fears by citizenship and legal status, 2007 to 2018
Authors: Asad Asad L.
Published: April 2020

Deportation has become more commonplace in the United States since the mid-2000s. Latin American noncitizens—encompassing undocumented and documented immigrants—are targeted for deportation. Deportation’s threat also reaches naturalized and US-born citizens of Latino descent who are largely immune to deportation but whose loved ones or communities are deportable. Drawing on 6 y of data from the National Survey of Latinos, this article examines whether and how Latinos’ deportation fears vary by citizenship and legal status and over time. Compared with Latino noncitizens, Latino US citizens report lower average deportation fears. However, a more complex story emerges when examining this divide over time: Deportation fears are high but stable among Latino noncitizens, whereas deportation fears have increased substantially among Latino US citizens. These trends reflect a growing national awareness of—rather than observable changes to—deportation policy and practice since the 2016 US presidential election. The article highlights how deportation or its consequences affects a racial group that the US immigration regime targets disproportionately.
Convergent evolution of olfactory and thermoregulatory capacities in small amphibious mammals
Authors: Martinez Quentin , Clavel Julien , Esselstyn Jacob A. , Achmadi Anang S. , Grohé Camille , Pirot Nelly , Fabre Pierre-Henri
Published: April 2020

Olfaction and thermoregulation are key functions for mammals. The former is critical to feeding, mating, and predator avoidance behaviors, while the latter is essential for homeothermy. Aquatic and amphibious mammals face olfactory and thermoregulatory challenges not generally encountered by terrestrial species. In mammals, the nasal cavity houses a bony system supporting soft tissues and sensory organs implicated in either olfactory or thermoregulatory functions. It is hypothesized that to cope with aquatic environments, amphibious mammals have expanded their thermoregulatory capacity at the expense of their olfactory system. We investigated the evolutionary history of this potential trade-off using a comparative dataset of three-dimensional (3D) CT scans of 189 skulls, capturing 17 independent transitions from a strictly terrestrial to an amphibious lifestyle across small mammals (Afrosoricida, Eulipotyphla, and Rodentia). We identified rapid and repeated loss of olfactory capacities synchronously associated with gains in thermoregulatory capacity in amphibious taxa sampled from across mammalian phylogenetic diversity. Evolutionary models further reveal that these convergences result from faster rates of turbinal bone evolution and release of selective constraints on the thermoregulatory-olfaction trade-off in amphibious species. Lastly, we demonstrated that traits related to vital functions evolved faster to the optimum compared to traits that are not related to vital functions.
Metrics that matter for assessing the ocean biological carbon pump
Authors: Buesseler Ken O. , Boyd Philip W. , Black Erin E. , Siegel David A.
Published: April 2020

The biological carbon pump (BCP) comprises wide-ranging processes that set carbon supply, consumption, and storage in the oceans’ interior. It is becoming increasingly evident that small changes in the efficiency of the BCP can significantly alter ocean carbon sequestration and, thus, atmospheric CO
2
and climate, as well as the functioning of midwater ecosystems. Earth system models, including those used by the United Nation’s Intergovernmental Panel on Climate Change, most often assess POC (particulate organic carbon) flux into the ocean interior at a fixed reference depth. The extrapolation of these fluxes to other depths, which defines the BCP efficiencies, is often executed using an idealized and empirically based flux-vs.-depth relationship, often referred to as the “Martin curve.” We use a new compilation of POC fluxes in the upper ocean to reveal very different patterns in BCP efficiencies depending upon whether the fluxes are assessed at a fixed reference depth or relative to the depth of the sunlit euphotic zone (Ez). We find that the fixed-depth approach underestimates BCP efficiencies when the Ez is shallow, and vice versa. This adjustment alters regional assessments of BCP efficiencies as well as global carbon budgets and the interpretation of prior BCP studies. With several international studies recently underway to study the ocean BCP, there are new and unique opportunities to improve our understanding of the mechanistic controls on BCP efficiencies. However, we will only be able to compare results between studies if we use a common set of Ez-based metrics.
Reconstitution of polythioamide antibiotic backbone formation reveals unusual thiotemplated assembly strategy
Authors: Dunbar Kyle L. , Dell Maria , Gude Finn , Hertweck Christian
Published: April 2020

Significance

Nonribosomal peptides (NRPs) are a vast class of natural products and an important source of therapeutics. Typically, these secondary metabolites are assembled by NRP synthetases (NRPSs) that function on substrates covalently linked to the enzyme by a thioester, in a process known as thiotemplated biosynthesis. Although NRPS-independent assembly pathways are known, all are nonthiotemplated. Here we report an NRPS-independent yet thiotemplated pathway for NRP biosynthesis and demonstrate that members of the ATP-grasp and cysteine protease families form the β-peptide backbone of an antibiotic. Armed with this knowledge, we provide genomic evidence that this noncanonical assembly pathway is widespread in bacteria. Our results will inspire future genome mining efforts for the discovery of potential therapeutics that otherwise would be overlooked.
Signature of a pair of Majorana zero modes in superconducting gold surface states
Authors: Manna Sujit , Wei Peng , Xie Yingming , Law Kam Tuen , Lee Patrick A. , Moodera Jagadeesh S.
Published: April 2020

Under certain conditions, a fermion in a superconductor can separate in space into two parts known as Majorana zero modes, which are immune to decoherence from local noise sources and are attractive building blocks for quantum computers. Promising experimental progress has been made to demonstrate Majorana zero modes in materials with strong spin–orbit coupling proximity coupled to superconductors. Here we report signatures of Majorana zero modes in a material platform utilizing the surface states of gold. Using scanning tunneling microscope to probe EuS islands grown on top of gold nanowires, we observe two well-separated zero-bias tunneling conductance peaks aligned along the direction of the applied magnetic field, as expected for a pair of Majorana zero modes. This platform has the advantage of having a robust energy scale and the possibility of realizing complex designs using lithographic methods.
A common polymorphism in the mechanosensitive ion channel
PIEZO1
is associated with protection from severe malaria in humans
Authors: Nguetse Christian N. , Purington Natasha , Ebel Emily R. , Shakya Bikash , Tetard Marilou , Kremsner Peter G. , Velavan Thirumalaisamy P. , Egan Elizabeth S.
Published: April 2020

Significance

The clinical presentation of
Plasmodium falciparum
malaria as severe versus uncomplicated is influenced by host genetic factors. Recently, a gain-of-function mutation in the mechanosensitive ion channel
PIEZO1
was shown to protect mice against cerebral malaria, but its role in human malaria is unknown. Here we investigated a common
PIEZO1
variant that encodes a mild gain-of-function mutant in human erythrocytes, and show that it is associated with malaria protection in Gabonese children. We found an epistatic relationship between
PIEZO1
E756del and the sickle cell trait. While parasite growth and cell hydration were normal, surface expression of PfEMP-1 was reduced in the mutant cells. Understanding the link between common
PIEZO1
variants and malaria susceptibility may yield new therapies for malaria.
Aquatic stem group myriapods close a gap between molecular divergence dates and the terrestrial fossil record
Authors: Edgecombe Gregory D. , Strullu-Derrien Christine , Góral Tomasz , Hetherington Alexander J. , Thompson Christine , Koch Markus
Published: April 2020

Significance

Most arthropod diversity is now found on land, with hexapods (insects), arachnids, and myriapods being major terrestrial radiations. Molecular dating consistently predicts that these groups have earlier evolutionary origins than are recorded by fossils. A reason for this difference between molecular- and fossil-based age estimates is that few candidates for marine or freshwater stem groups of these terrestrial lineages have been identified. A Devonian euthycarcinoid arthropod preserves details of the head shared by myriapods, adding support to the theory that they are each other’s closest relative. The fossil record of euthycarcinoids in the Cambrian, including trackways made on tidal flats, clarifies the marine-to-terrestrial transition in the myriapod lineage and reconciles molecular and fossil-based estimates for the timing of myriapod origins.
Kinetic control of stationary flux ratios for a wide range of biochemical processes
Authors: Mallory Joel D. , Kolomeisky Anatoly B. , Igoshin Oleg A.
Published: April 2020

Significance

Chemical kinetic formalism is widely used to describe biochemical processes, including channel transport, enzymatic catalysis, genetic regulation, and signal transduction. Fundamentally, transitions between biochemical states are defined by the underlying free energy landscapes, but few general results relate the landscape features to biologically relevant properties. At equilibrium, the probabilities of discrete states only depend on their energies and not on the energy barriers in between states. However, few general claims about nonequilibrium steady states have been formulated. Here, for nonequilibrium steady states of networks with quasi-order transitions, we prove that the flux ratios are invariant to energy perturbations of the states and, therefore, are only affected by the free energy barriers. Biological implications of the result are illustrated for three distinct biological processes.
Actuation and locomotion driven by moisture in paper made with natural pollen
Authors: Zhao Ze , Hwang Youngkyu , Yang Yun , Fan Tengfei , Song Juha , Suresh Subra , Cho Nam-Joon
Published: April 2020

Significance

Much progress has been made in developing bioinspired sensors and actuators based on engineered synthetic materials, although there remains a critical need to incorporate cost-effective and eco-friendly materials. Here naturally abundant pollen grains are used as a material template to produce paper that sensitively and reversibly responds as an actuator to variations in environmental humidity. The actuating properties of the all-natural paper are readily tuned by material characteristics, such as sheet thickness and surface roughness. We demonstrate self-actuation of the pollen-based paper by mimicking flower blooming. The results presented here point to pathways for the creation of self-propelled robots, flexible electronics, and multifunctional devices. They also offer the potential for digital printing and fabrication of complex and programmable natural actuators.
Effectiveness of convalescent plasma therapy in severe COVID-19 patients
Authors: Duan Kai , Liu Bende , Li Cesheng , Zhang Huajun , Yu Ting , Qu Jieming , Zhou Min , Chen Li , Meng Shengli , Hu Yong , Peng Cheng , Yuan Mingchao , Huang Jinyan , Wang Zejun , Yu Jianhong , Gao Xiaoxiao , Wang Dan , Yu Xiaoqi , Li Li , Zhang Jiayou , Wu Xiao , Li Bei , Xu Yanping , Chen Wei , Peng Yan , Hu Yeqin , Lin Lianzhen , Liu Xuefei , Huang Shihe , Zhou Zhijun , Zhang Lianghao , Wang Yue , Zhang Zhi , Deng Kun , Xia Zhiwu , Gong Qin , Zhang Wei , Zheng Xiaobei , Liu Ying , Yang Huichuan , Zhou Dongbo , Yu Ding , Hou Jifeng , Shi Zhengli , Chen Saijuan , Chen Zhu , Zhang Xinxin , Yang Xiaoming
Published: April 2020

Currently, there are no approved specific antiviral agents for novel coronavirus disease 2019 (COVID-19). In this study, 10 severe patients confirmed by real-time viral RNA test were enrolled prospectively. One dose of 200 mL of convalescent plasma (CP) derived from recently recovered donors with the neutralizing antibody titers above 1:640 was transfused to the patients as an addition to maximal supportive care and antiviral agents. The primary endpoint was the safety of CP transfusion. The second endpoints were the improvement of clinical symptoms and laboratory parameters within 3 d after CP transfusion. The median time from onset of illness to CP transfusion was 16.5 d. After CP transfusion, the level of neutralizing antibody increased rapidly up to 1:640 in five cases, while that of the other four cases maintained at a high level (1:640). The clinical symptoms were significantly improved along with increase of oxyhemoglobin saturation within 3 d. Several parameters tended to improve as compared to pretransfusion, including increased lymphocyte counts (0.65 × 10
9
/L vs. 0.76 × 10
9
/L) and decreased C-reactive protein (55.98 mg/L vs. 18.13 mg/L). Radiological examinations showed varying degrees of absorption of lung lesions within 7 d. The viral load was undetectable after transfusion in seven patients who had previous viremia. No severe adverse effects were observed. This study showed CP therapy was well tolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. The optimal dose and time point, as well as the clinical benefit of CP therapy, needs further investigation in larger well-controlled trials.
The impact of teaching quality and learning time on primary EFL learners’receptive proficiency
Authors: Wilden Eva , Porsch Raphaela
Published: April 2020

This contribution presents the preliminary findings from the TEPS study (Teaching English in Primary
Schools). The study is situated in Germany where primary foreign language (FL) education has been compulsory since
2004, with pupils beginning FL education – mostly English as a FL (EFL) – in either year 1 or 3. Generally, this introduction of
primary FL education has not been empirically evaluated, in spite of various open research questions: (1) Does the receptive EFL
proficiency of learners at the end of primary education in year 4 differ depending on their learning time (duration & age of
onset)? (2) Is there a correlation between teaching quality (learners’ perspective) and learners’ receptive EFL proficiency as
well as their attitudes towards learning EFL? Prior studies (e.g. Demircioglu, 2010)
gave first indications that learners with an earlier start achieve better receptive skills. Yet, findings from these samples
cannot be generalized and are altogether inconclusive (e.g. Jaekel, van Ackern, Schurig, &
Ritter, 2017). Studies investigating correlations between teaching quality and learner achievements in primary school
are mainly based in maths and science education (e.g. TIMSS-2015: see Rieser, Stahns,
Walzebug, & Wendt, 2016). Thus, the TEPS study situated in both applied linguistics and educational science is
addressing some of these research deficits by (a) testing pupils’ receptive EFL proficiency at the end of primary education in
year 4 (n = 269) and (b) surveying teaching quality and learner attitudes towards EFL. The study has been
conducted in two federal states with different ages of onset (year 1 vs. year 3). Aside from the theoretical background and
context of the study this paper will present the complex research design followed by preliminary findings from the pilot study
giving insights into the questions raised above (for the main study see Wilden, Porsch, &
Schurig, 2020).