bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning Orthographic and Semantic Representations Simultaneously During Shared Reading
Authors: Shakory Sharry , Chen Xi , Deacon S. Hélène
Published: February 2021

Purpose

The value of shared reading as an opportunity for learning word meanings, or semantics, is well established; it is less clear whether children learn about the orthography, or word spellings, in this context. We tested whether children can learn the spellings and meanings of new words at the same time during a tightly controlled shared reading session. We also examined whether individual differences in either or both of orthographic and semantic learning during shared reading in English were related to word reading in English and French concurrently and 6 months longitudinally in emergent English–French bilinguals.

Method

Sixty-two Grade 1 children (35 girls;
M
age
= 75.89 months) listened to 12 short stories, each containing four instances of a novel word, while the examiner pointed to the text. Choice measures of the spellings and meanings of the novel words were completed immediately after reading each set of three stories and again 1 week later. Standardized measures of word reading as well as controls for nonverbal reasoning, vocabulary, and phonological awareness were also administered.

Results

Children scored above chance on both immediate and delayed measures of orthographic and semantic learning. Orthographic learning was related to both English and French word reading at the same time point and 6 months later. In contrast, the relations between semantic learning and word reading were nonsignificant for both languages after including controls.

Conclusion

Shared reading is a valuable context for learning both word meanings and spellings, and the learning of orthographic representations in particular is related to word reading abilities.

Supplemental Material

https://doi.org/10.23641/asha.13877999
Developing Interpersonal and Counseling Skills Through Mixed-Reality Simulation in Communication Sciences and Disorders
Authors: Perryman Twyla , Sandefur Carlie , Morris Chelsea T.
Published: February 2021

Purpose

Simulation is increasingly becoming a valuable tool for training and educating students in communication sciences and disorders (CSD). The purpose of this study is to examine the impact of a mixed-reality simulation on CSD students' perceptions of their ability to apply clinical and counseling skills. Additionally, this study sought to investigate the overall efficacy and acceptance of this type of clinical simulation experience for undergraduate CSD students.

Method

A total of 29 undergraduate students participated in a clinical simulation experience that used actor-controlled avatars in a mixed-reality simulation environment to practice collecting case history information and delivering diagnostic news to parents of a child client. All students completed pre- and postsimulation questionnaires that rated the impact of the clinical simulation experience on their confidence in demonstrating targeted clinical skills and their general attitudes about their participation. Additionally, five lead participants participated in follow-up interviews to gather data to best describe students' perceptions. Quantitative and qualitative data were recorded and analyzed.

Results

The majority of the students exhibited positive attitudes toward the mixed-reality clinical simulation experience and reported an increase in their perceived ability to apply several counseling skills (e.g., listening and selective feedback) following the session. Analysis showed that the perceived confidence levels on seven out of the 17 targeted skill items increased on the postevent questionnaire to a level of statistical significance and that the simulation experience was described as meaningful and supportive for increasing confidence.

Conclusions

Mixed-reality clinical simulation may be a useful tool for teaching interpersonal communication and counseling skills for students, including undergraduates, in CSD. Additionally, the use of mixed-reality technology in this study produced similar results seen with other clinical simulation methods such as standardized patients or computer-based simulations.
Efficient resilient dynamic co‐estimation framework for cyber‐physical systems under sensor attacks
Authors: Kazemi Zahra , Safavi Ali Akbar , Setoodeh Peyman
Published: February 2021

In this study, a novel co‐estimation approach is proposed for dynamic state estimation of cyber‐physical systems (CPSs) subjected to sensor attacks. In the proposed approach, the sensory measurements are preprocessed to extract some valuable information about the launched cyber‐attack. This information is then manipulated to form new state equations, which are augmented with the CPS model. The newly obtained model effectively represents the behaviour of both the CPS states as well as the launched cyber‐attack, and can be used for their co‐estimation. Two structures are suggested for the preprocessing of the sensory measurements that deploy Kalman filter (KF) and two‐step KF for co‐estimation of the states and cyber‐attacks. To effectively handle the concurrent effects of cyber‐attacks and unknown inputs on the CPS co‐estimation process, some auxiliary outputs are generated using high‐gain approximate differentiators to realise the required matching conditions. The proposed dynamic co‐estimation approach improves accuracy via considering the inter‐correlation between the CPS states and the cyber‐attacks. To demonstrate the viability of the proposed co‐estimation method, thorough stability and feasibility analysis are provided. Furthermore, extensive simulations are performed on a well‐known CPS‐the IEEE 14‐bus test system‐ to demonstrate the effectiveness of the proposed approach.
Controlled islanding algorithm for AC/DC hybrid power systems utilising DC modulation
Authors: Fan Xinkai , Crisostomi Emanuele , Thomopulos Dimitri , Zhang Baohui , Yang Songhao
Published: February 2021

The controlled islanding problem is typically considered only for pure ac power systems, with the ultimate objective of either minimising power imbalance or power‐flow among islands. However, as ac/dc hybrid power systems are becoming popular worldwide, current controlled islanding schemes should be redesigned to take into account the presence of high‐voltage dc (HVDC) links, possibly connecting different islands. Accordingly, in this study, the authors solve the classic islanding problem combining HVDC power modulation with the conventional ac cutset search. The flexibility of the HVDC allows the authors' strategy to jointly capture the previously mentioned objectives, and provides even lower power imbalances than the minimum imbalance strategy, at a relatively small cost of increasing power‐flow impact. Then, the optimisation problem is formulated as a mixed‐integer linear programming problem, which can be conveniently solved with existing commercial solvers. Finally, they validate their proposed strategy in two case studies, corresponding to a modified IEEE‐118 system and to the China Southern Power Grid system. In both cases, dynamic simulations show that their proposed approach outperforms classic algorithms where the presence of HVDC power modulation is not explicitly taken into account.
Hybrid model for predicting anomalous large passenger flow in urban metros
Authors: Zheng Zhihao , Ling Ximan , Wang Pu , Xiao Jianhe , Zhang Fan
Published: February 2021

Machine learning models have been widely adopted for passenger flow prediction in urban metros; however, the authors find machine learning models may underperform under anomalous large passenger flow conditions. In this study, they develop a prediction framework that combines the advantage of complex network models in capturing the collective behaviour of passengers and the advantage of online learning algorithms in characterising rapid changes in real‐time data. The proposed method considerably improves the accuracy of passenger flow prediction under anomalous conditions. This study can also serve as an exploration of interdisciplinary methods for transportation research.
Energy‐efficient approach combining train speed profile and timetable optimisations for metro operations
Authors: Ran Xin‐Chen , Chen Shao‐Kuan , Liu Ge‐Hui , Bai Yun
Published: February 2021

Rising energy cost and environment‐friendly awareness make energy conservation a key issue for metro operation. Reducing traction energy consumption and improving the utilisation of regenerative braking energy are two efficient solutions to conserve energy. Two optimisation models are proposed in this study for metro systems to minimise the energy consumption by exploring energy‐efficient speed profile and optimum timetable. An analytical formulation through finding suitable force coefficients and driving regime‐switching points is developed to investigate the optimal speed profile of a single train during its movement along complex rail tracks considering gradients, curves, tunnels and speed limits. Moreover, the synchronisation of accelerating and braking trains is much necessarily implemented when a timetable optimisation model is established for the energy‐efficient operation by adjusting the dwell times, running times and turnaround times of multiple trains. A combined particle swarm optimisation and genetic algorithm are addressed to solve the model. The case studies from the actual data of a Beijing Metro line are carried out to verify the feasibility and availability of the proposed approach. Their results show that the net energy consumption of trains along the metro line is reduced by 10.99% by combining the optimal speed profiles and timetable.
Efficient deep learning based method for multi‐lane speed forecasting: a case study in Beijing
Authors: Lu Wenqi , Yi Ziwei , Liu Wan , Gu Yuanli , Rui Yikang , Ran Bin
Published: February 2021

Real‐time and accurate multi‐lane traffic condition forecasting is of great importance to the connected and automated vehicle highway system. However, the majority of existing deep learning based traffic prediction methods focus on pursuing the precision of the methods while neglect to improve the efficiency of the methods. To achieve the high accuracy and high efficiency of multi‐lane traffic flow prediction simultaneously, this study proposes a novel combination method via the integration of the clockwork recurrent neural network (CWRNN) and random forest (RF) method, which is RF‐CWRNN. To the best of the authors’ knowledge, this is the first time that the CWRNN is introduced to capture the temporal feature of lane‐level traffic flow and make traffic speed prediction. Meanwhile, the RF method is employed to measure the temporal relevance of the traffic flow and determine the optimal input time window. To verify the performance of the RF‐CWRNN method, the ground‐truth data of the expressways in Beijing were utilised to carry out experiments. The results indicate that the RF‐CWRNN method is superior to the baseline models in terms of accuracy and robustness. Besides, the proposed method can save plenty of training time compared with the classical long short‐term memory neural network.
Sustained oscillations and bifurcations in three‐phase voltage source converter tied to AC grid
Authors: Ma Rui , Yang Ziqian , Cheng Shijie , Zhan Meng
Published: February 2021

Recently large‐scale integration of power‐electronic‐based devices has made system‐level oscillations occur frequently, which posed a big challenge for modern power grids. Previous studies mainly treated sustained oscillations under the framework of (linear) small‐signal stability and/or by incorporating the impact of current saturation, but seldom considered system non‐linearity like phase‐locked‐loop. In this study, the authors established a sixth‐order non‐linear model for a three‐phase voltage‐source converter tied to AC grid, and studied its dynamics completely from non‐linear system theory and signal analysis technique, with all parameters including current controllers, phase‐locked‐loop, line inductance, and grid voltage. They found that the operation point usually becomes unstable by Hopf bifurcation, and the sustained oscillations are possible only for super‐critical Hopf bifurcation. Based on these observations, sustained periodic oscillation should be treated as a limit cycle even without saturation. With saturation, some other phenomena have also been found, such as saturation‐induced instability and saturation‐restricted oscillation. In addition, they discovered that for sustained oscillations, the usual purely sinusoidal three‐phase currents exhibit the form of or , where () denotes basic (modal oscillation) frequency with c a constant. This work could provide an improved understanding of sustained oscillations and associated system dynamics in an overall perspective manner.
Flexible virtual capacitance control strategy for a DC microgrid with multiple constraints
Authors: Meng Jianhui , Zhang Yun , Wang Yi , Song Meiqi , Zhao Pengfei , Liu Bao
Published: February 2021

In a DC microgrid, the anti‐interference ability of bus voltage can easily become vulnerable due to low inertia caused by a large number of power electronic converters. This has already challenged the system stability and practicability in DC girds. In this study, a flexible virtual capacitance (FVC) control strategy with multiple constraints (MCs) is proposed to guarantee the security and stability of the DC microgrid, where the system stability, dynamic characteristics, actual operation requirements and realisability are considered as MCs. The FVC controller, which mainly modifies the reference current in voltage source converter by flexibly regulating virtual capacitance value, is given to provide inertial support and improve voltage quality. The stable operating boundary calculation based on small signal model and key control parameters design are further introduced into the control loop. This can ameliorate the dynamic response of the microgrid and obtain the better engineering practicability. Finally, experiment tests on a controller‐level hardware‐in‐the‐loop simulation platform are carried out to verify the validity of the proposed strategy.
Enhancing hosting capacity of intermittent wind turbine systems using bi‐level optimisation considering OLTC and electric vehicle charging stations
Authors: Ali Abdelfatah , Mahmoud Karar , Lehtonen Matti
Published: February 2021

Worldwide, the hosting capacity of renewable energy sources (RES) is remarkably expanded in distribution systems. One of the most auspicious RES is wind turbine systems (WTSs), which can improve the performance of distribution systems. In turn, the integration of high WTS penetrations can also deviate the system operation away from the standard condition. To tackle this issue, we propose a method for enhancing the hosting capacity of multiple WTSs considering their intermittent generations in distribution systems. The proposed method considers the operation of the on‐load tap changer (OLTC), allowing to solve voltage problems efficiently. Especially, the proposed method optimises the charging/discharging power of electric vehicles (EVs), which can contribute positively to regulating WTS intermittent generation. Additionally, the reactive power support of WTSs, complying with the IEEE 1547:2018 standard, is incorporated in the planning model of WTSs. To solve such an optimisation problem, a bi‐level optimisation algorithm is developed based on the gravitational search algorithm. Comprehensive simulation results are performed on the 69‐bus distribution feeder interconnected to four EV stations. Based on the results, the proposed approach can efficiently enhance/increase the hosting capacity of WTSs in distribution systems, thanks to the consideration of OLTC, reactive power support of WTSs and EVs.
Nanoparticules d’or pour les biocapteurs : lecture optique de la reconnaissance moléculaire
Authors: Boujday Souhir , Salmain Michèle
Published: February 2021

Les propriétés extraordinaires des nanoparticules d’or et/ou d’argent en ont fait des objets courtisés par les scientifiques toutes disciplines confondues. L’intensité de leur couleur ainsi que leur grande sensibilité optique au milieu environnant en font de puissants transducteurs pour les biocapteurs ; que ce soit grâce à des spectrophotomètres ou simplement par observation à l’oeil nu. Elles assurent la lecture de la reconnaissance moléculaire via des scénarios variés alliant simplicité et faible coût.
Wo das Leben pulsiert – Novellas Generationenhaus
Authors: Köller Looser Bianca
Published: February 2021

Gemeinsam mit ihrem Mann entwickelte Ergotherapeutin Bianca Köller Looser ein Haus für mehrere Generationen in der Schweiz. Im „Novellas“ kommen rüstige Senioren, Menschen mit Demenz, Kinder und Besucher miteinander in Kontakt. Einblick in ein Herzensprojekt.
Reize adäquat verarbeiten – Sensorische Integrationstherapie bei Kindern mit Autismus
Authors: Miller Meike
Published: February 2021

Autistische Kinder wirken oft, als stünden sie unter enormem Stress. Meike Miller hilft ihnen dabei, ihr Erregungsniveau zu regulieren, und schafft damit die Voraussetzung für weiterführendes Lernen. Dazu gehört, neben Regulationsangeboten, die Umwelt anzupassen, die Sinne des Kindes zu entlasten sowie Elternberatung anzubieten.
Angehörigenarbeit aus der Perspektive von Pflegepersonen mobiler Palliativteams – eine qualitative Studie
Authors: Kreyer Christiane , Strauß-Mair Michaela
Published: February 2021

Hintergrund Angehörige zu unterstützen ist eine zentrale Aufgabe in der Palliativversorgung zu Hause. Als Teil des interprofessionellen Teams übernehmen Pflegepersonen dabei eine wichtige Rolle. Ziel der Studie war es, die Perspektive von Pflegepersonen mobiler Palliativteams auf Angehörigenarbeit in der häuslichen Palliativversorgung zu erheben.

Methodik In der explorativen qualitativen Studie wurden Gruppendiskussionen und qualitative Einzelinterviews mit spezialisierten Palliativpflegepersonen von mobilen Palliativteams aus Österreich durchgeführt und anhand der qualitativen Inhaltsanalyse nach Mayring ausgewertet.

Ergebnisse Es wurden 2 Gruppendiskussionen mit insgesamt 11 Teilnehmenden und 3 Einzelinterviews durchgeführt. Angehörigenarbeit ist ein zentrales und komplexes Handlungsfeld für die befragten Pflegepersonen, in das ein großer Teil der Arbeitszeit investiert wird. Es wurden 5 Kategorien von Pflegeinterventionen identifiziert: „Aufbau einer tragfähigen Beziehung“, „Koordination und Kooperation“, „Sicherheit vermitteln und Empowerment“, „Krisen vorbeugen“ sowie „Trauer unterstützen und Beziehung abschließen“. Herausforderungen waren familiäre Konflikte, der späte Einbezug von Palliativversorgungsangeboten und die frühe Entlassung aus stationärer Versorgung. Die nötigen Kompetenzen für Angehörigenarbeit wurden in der Aus- und Weiterbildung nur in geringem Ausmaß erworben.

Schlussfolgerung Angehörigenarbeit ist eine Kernaufgabe häuslicher Palliativpflege und sollte deutlich mehr Aufmerksamkeit in Praxis, Lehre und Forschung erhalten um deren Qualität weiterzuentwickeln.
Wearables als unterstützendes Tool für den Paradigmenwechsel in der Versorgung von Parkinson Patienten
Authors: Thun-Hohenstein Caroline , Klucken Jochen
Published: February 2021

Tragbare Sensoren – „Wearables“ – eignen sich, Funktionsstörungen bei Parkinson Patienten zu erheben und werden zur Prävention, Prädiktion, Diagnostik und Therapieunterstützung genutzt. In der Forschung erhöhen sie die Reliabilität der erhobenen Daten und stellen bessere Studien-Endpunkte dar, als die herkömmlichen, subjektiven und wenig quantitativen Rating- und Selbstbeurteilungsskalen. Untersucht werden motorische Symptome wie Tremor, Bradykinese und Gangstörungen und auch nicht motorische Symptome. In der Home-Monitoringanwendung kann der Ist-Zustand des Patienten im realen Leben untersucht werden, die Therapie überwacht, die Adhärenz verbessert und die Compliance überprüft werden. Zusätzlich können Wearables interventionell zur Verbesserung von Symptomen eingesetzt werden wie z. B. Cueing, Gamification oder Coaching. Der Transfer von Laborbedingungen in den häuslichen Alltag ist eine medizinisch-technische Herausforderung. Optimierte Versorgungsmodelle müssen entwickelt werden und der tatsächliche Nutzen für den individuellen Patienten in weiteren Studien belegt werden.
Impact of Smoking, Obesity and Maternal Diabetes on SHBG Levels in Newborns
Authors: Aydin Banu Kucukemre , Yasa Beril , Moore Joseph P. , Yasa Cenk , Poyrazoglu Sukran , Bas Firdevs , Coban Asuman , Darendeliler Feyza , Winters Stephen J.
Published: February 2021

Background Low levels of SHBG have become a marker for insulin resistance and diabetes. Babies born to mothers who are obese, have diabetes, or smoke during pregnancy are at greater risk of developing obesity and diabetes later in life.

Aims To examine the impact of maternal obesity, diabetes and smoking on SHBG levels in newborns.

Study design This cross-sectional study is part of an ongoing multicenter, longitudinal study.

Subjects 98 healthy newborns and their parents, including 16 mothers with diabetes and 31 mothers with a smoking history.

Outcome measures Cord blood and second day venipuncture samples were collected for measurement of SHBG and insulin.

Results Babies born to mothers with diabetes had lower SHBG levels in cord blood [14.0 (8.9–20.4) vs. 19.6 (14.9–25.1) nmol/L; p=0.011] and on day 2 [18.8 (12.6–21.2) vs. 22.9 (17.1–29.1) nmol/L; p=0.015] than controls. Maternal diabetes remained negatively associated with SHBG levels in cord blood (p=0.02) and on day 2 (p=0.04) when adjusted for mothers’ age, smoking status, pre-pregnancy weight and weight gain during pregnancy. SHBG levels in cord blood and day 2 samples were similar in babies born to mothers who were overweight-obese but not diabetic vs. normal weight, or were smokers when compared to non-smokers.

Conclusions: SHBG levels are lower in newborns born to mothers with diabetes than without diabetes, and may be a marker for babies’ life-long risk for abnormal metabolic health. On the other hand, the adverse effects of tobacco smoke on the fetus do not appear to directly influence SHBG levels.
Synthesis of Chiral Amines by C–C Bond Formation with Photoredox Catalysis
Authors: Friestad Gregory K. , Cullen Stephen T. J.
Published: February 2021

Chiral amines are key substructures of biologically active natural products and drug candidates. The advent of photoredox catalysis has changed the way synthetic chemists think about building these substructures, opening new pathways that were previously unavailable. New developments in this area are reviewed, with an emphasis on C–C bond constructions involving radical intermediates generated through photoredox processes.

1 Introduction

2 Radical–Radical Coupling of α-Amino Radicals

2.1 Radical–Radical Coupling Involving Amine Oxidation

2.2 Radical–Radical Coupling Involving Imine Reduction

2.3 Couplings Involving both Amine Oxidation and Imine Reduction

3 Addition Reactions of α-Amino Radicals

3.1 Conjugate Additions of α-Amino Radicals

3.2 Addition of α-Amino Radicals to Heteroaromatic Systems

3.3 Cross Coupling via Additions to Transition Metal Complexes

4 Radical Addition to C=N Bonds Using Photoredox Catalysis

4.1 Intramolecular Radical Addition to C=N Bonds

4.2 Intermolecular Radical Addition to C=N Bonds

5 Conclusion
On Pyridopyrazinol Chemistry: Synthesis of Chemiluminescent Substances
Authors: Janin Yves L. , Gagnot Glwadys , Legrand Pierre , Tadros Amira , Ezzahra Hibti Fatima , Quatela Alessia
Published: February 2021

Our work on new chemiluminescent substances related to the marine luciferin coelenterazine (λmax = 465 nm) led us to attempt the synthesis of four nitrogen-rich pyridopyrazine-bearing analogues. Accordingly, the preparation of the corresponding benzyl-bearing pyridopyrazinols is studied. By varying the conditions for the condensation of phenylpyruvic acid with 1,2-diaminopyridine or 3,4-diaminopyridine, all the possible pyridopyrazin-2-ol regioisomers are isolated and properly characterized, including by means of crystallographic studies. The ensuing syntheses of the halogenated pyridopyrazines are fraught with difficulties ranging from extensive decomposition to an unexpected ring contraction. In one instance, the inherently reductive mixture of phosphorus oxychloride and phosphorus trichloride provides 2-benzyl-3-chloropyrido[2,3-b]pyrazine. This precursor is then transformed into the target O-acetylated luciferin (6,8-dibenzylimidazo[1,2-a]pyrido[3,2-e]pyrazin-9-yl acetate). The ‘benzo’ derivative of this analogue (i.e., 2,12-dibenzylimidazo[1′,2′:1,6]pyrazino[2,3-c]isoquinolin-3-yl acetate) is also prepared and the chemiluminescence emission spectra of these compounds are determined in a phosphate buffer (λmax = 546 and 462 nm).
Recent Advances in Transition-Metal-Free (4+3)-Annulations
Authors: Lam Heather , Lautens Mark , Abel-Snape Xavier , Köllen Martin F.
Published: February 2021

(4+3)-Annulations are incredibly versatile reactions which combine a 4-atom synthon and a 3-atom synthon to form both 7-membered carbocycles as well as heterocycles. We have previously reviewed transition-metal-catalyzed (4+3)-annulations. In this review, we will cover examples involving bases, NHCs, phosphines, Lewis and Brønsted acids as well as some rare examples of boronic acid catalysis and photocatalysis. In analogy to our previous review, we exclude annulations involving cyclic dienes like furan, pyrrole, cyclohexadiene or cyclopentadiene, as Chiu, Harmata, Fernándes and others have recently published reviews encompassing such substrates. We will however discuss the recent additions (2010–2020) to the literature on (4+3)-annulations involving other types of 4-atom-synthons.

1 Introduction

2 Bases

3 Annulations Using N-Heterocyclic Carbenes

3.1 N-Heterocyclic Carbenes (NHCs)

3.2 N-Heterocyclic Carbenes and Base Dual-Activation

4 Phosphines

5 Acids

5.1 Lewis Acids

5.2 Brønsted Acids

6 Boronic Acid Catalysis and Photocatalysis

7 Conclusion
Time from Injury Is the Key Predictor of Meniscal Injury in ACL-Deficient Knees
Authors: Mortazavi Seyed Mohammad Javad , Moharrami Alireza , Tamhri S. S. , Okati Ali , Shamabadi Ahmad
Published: February 2021

The meniscus is one of the most important structures of the knee that needs to be saved if possible. Previous studies showed that increasing time from an anterior cruciate ligament (ACL) injury (TFI) could lead to a meniscal tear, especially medial meniscus (MM). We developed the present study to see if the TFI alone is a predictor of meniscal injury in ACL-deficient knees. We included 111 patients who had a reconstructed ACL injury at our institution from March 2015 to March 2016 in this retrospective cohort study. All demographic data, including age, gender, and body mass index (BMI), were collected. We also recorded the mechanism of injury and the TFI. We extracted the meniscal condition at the time of surgery from the surgical report. All patients were followed up for a mean of 23 months, and the Lysholm score and pain visual analog scale (VAS) score were obtained. The mean TFI of patients with MM tear was 17.4 ± 16.8 months, which was significant than the patients with lateral meniscal (LM) tear (9.3 ± 8.3 months) and intact meniscus (7.4 ± 8.1 months) (p = 0.001). Patients with TFI less than 6 months had a significantly lower rate of MM tear, and increasing TFI more than 6 months could increase the rate of MM tear (p = 0.001). We could not find any association between age, BMI, and gender and meniscal injury. At the latest follow-up, Lysholm and VAS scores in patients with and without meniscal tear were the same. Our study confirms that increasing time from the ACL injury would increase the risk of MM damage. The cutoff point for this risk factor is 6 months from initial injury; therefore, to save the meniscus, it might be better to perform ACL reconstruction within 6 months in ACL-deficient knees.
Biplane Medial Opening-Wedge High Tibial Osteotomy Increases Posterior Tibial Slope more than Uniplane Osteotomy
Authors: Suh Dong Won , Nha Kyung Wook , Han Seung Beom , Cheong Kuhoang , Kyung Bong Soo
Published: February 2021

Few clinical studies have compared uniplane high tibial osteotomy (HTO) with biplane HTO. The study aim was to compare the radiological and clinical results of uniplane HTO and biplane HTO, especially in terms of the increase in the posterior tibial slope (PTS). Medial opening-wedge HTO patients' medical records and radiological results from a single institution were retrospectively reviewed. Pre- and postoperative serial radiographs, including the Rosenberg, lateral view, and standing anteroposterior view of the whole lower extremity, magnetic resonance imaging at postoperative day 2, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score at postoperative 2 years were reviewed to evaluate radiological and clinical results, including the change in PTS. A total of 61 knees, including 34 for uniplane and 27 for biplane HTOs, were enrolled. There were no significant differences in the pre- and postoperative mechanical angles or incidences of the lateral hinge fractures, and all patients showed complete union at postoperative 2 years. The PTS was increased more in the biplane group than in the uniplane group (3.1 ± 2.6 in biplane vs. 0.8 ± 1.7 in uniplane, p < 0.05). The WOMAC scores were 72 ± 9.3 in the uniplane and 75 ± 5.8 in the biplane group (not significant). The increase in PTS was lower in uniplane medial opening HTO than in biplane HTO.
Cerebellopontine Angle Epidermoids: Comparative Results of Microscopic and Endoscopic Excision Using the Retromastoid Approach”
Authors: Singh Suyash , Das Kuntal Kanti , Kumar Krishna , Rangari Kamlesh , Dikshit Priyadarshi , Bhaisora Kamlesh Singh , Sardhara Jayesh , Mehrotra Anant , Srivastava Arun Kumar , Jaiswal Awadhesh Kumar , Behari Sanjay
Published: February 2021

Background Densely packed neurovascular structures, often times inseparable capsular adhesions and sometimes a multicompartmental tumor extension, make surgical excision of cerebellopontine angle epidermoids (CPEs) a challenging task. A simultaneous or an exclusive endoscopic visualization has added a new dimension to the classical microscopic approaches to these tumors recently.

Methods Eighty-six patients (age: 31.6 ± 11.7 years, M:F = 1:1) were included. Nineteen patients (22.1%) had a multicompartmental tumor. Tumor extension was classified into five subtypes. Sixty-two patients underwent a pure microscopic approach (72%) out of which 10 patients (16%) underwent an endoscope-assisted surgery (11.6%) and 24 patients (28%) underwent an endoscope-controlled excision. Surgical outcomes were retrospectively analyzed.

Results Headache (53.4%), hearing loss (46.5%), and trigeminal neuralgia (41.8%) were the leading symptoms. Interestingly, 21% of the patients had at least one preexisting cranial nerve deficit. Endoscopic assistance helped in removing an unseen tumor lobule in 3 of 10 patients (30%). Pure endoscopic approach significantly reduced the hospital stay from 9.2 to 7.3 days (p = 0.012), and had a statistically insignificant yet a clearly noticeable lesser incidence of subtotal tumor excision (0 vs. 10%, p = 0.18) with comparable cranial nerve deficits but with a higher postoperative cerebrospinal fluid (CSF) leak rate (29% vs. 4.8%, p = 0.004).

Conclusion Endoscope assistance in CPE surgery is a useful addition to conventional microscopic retromastoid approach. Pure endoscopic excision in CPE is feasible, associated with a lesser duration of hospital stay, better extent of excision in selected cases, and it has a comparable cranial nerve morbidity profile albeit with a higher rate of CSF leak.
Occipital Neuralgia following Acoustic Neuroma Resection
Authors: Riedy Loren N. , Heiferman Daniel M. , Szujewski Caroline C. , Malina Giselle EK. , Rezaii Elhaum G. , Martin Brendan , Grahnke Kurt A. , Doerrler Michael , Leonetti John P. , Anderson Douglas E.
Published: February 2021

Background While postoperative outcomes of acoustic neuroma (AN) resection commonly consider hearing preservation and facial function, headache is a critical quality of life factor. Postoperative headache is described in the literature; however, there is limited discussion specific to occipital neuralgia (ON) following AN resection.

Objective The aim of this study is to investigate the effectiveness of conservative management and surgery.

Methods We conducted a retrospective review of 872 AN patients who underwent resection at our institution between 1988 and 2017 and identified 15 patients (1.9%) that met International Classification of Headache Disorders criteria for ON.

Results Of the 15 ON patients, surgical approaches included 13 (87%) retrosigmoid (RS), one (7%) translabyrinthine (TL), and one (7%) combined RS + TL. Mean clinical follow-up was 119 months (11–263). Six (40%) patients obtained pain relief through conservative management, while the remaining nine (60%) underwent surgery or ablative procedure. Three (38%) patients received an external neurolysis, four (50%) received a neurectomy, one (13%) had both procedures, and one (13%) received two C2 to 3 radio frequency ablations. Of the nine patients who underwent procedural ON treatment, seven (78%) patients achieved pain relief, one patient (11%) continued to have pain, and one patient (11%) was lost to follow-up. Of the six patients whose pain was controlled with conservative management and nerve blocks, five (83%) found relief by using neuropathic pain medication and one (17%) found relief on nonsteroidal anti-inflammatory drug.

Conclusion Our series demonstrates success with conservative management in some, but overall a minority (40%) of patients, reserving decompression only for refractory cases.
When Fat Hits the Brain: Intraventricular and Subarachnoid Fat Migration Secondary to a Complex Sacropelvic Fracture—Diagnosis and Treatment
Authors: Polemikos Manolis , Kiepe Felix , Al-Afif Shadi , Bronzlik Paul , Krauss Joachim K.
Published: February 2021

Massive migration of fat droplets in the ventricles and the subarachnoid space is a very rare sequel of spinal trauma. Owing to its rarity, knowledge about treatment and outcome remains limited. We report on the uncommon occurrence of massive subarachnoid and intraventricular fat dissemination in a 41-year-old man who suffered a complex sacropelvic fracture with spondylopelvic dissociation but who had no head injury. We show that early placement of an external ventricular drain with prolonged drainage for washout of the fat depots can prevent chronic hydrocephalus and subsequent shunt dependency.
Polyethylene Components in Primary Total Knee Arthroplasty: A Comprehensive Overview of Fixed Bearing Design Options
Authors: Kahlenberg Cynthia A. , Chalmers Brian , Sun Hyung Jin , Mayman David J. , Westrich Geoffrey H. , Haas Steven B. , Sculco Peter K.
Published: February 2021

The articular design of a polyethylene insert influences the kinematics and overall function of a total knee arthroplasty (TKA). Standard symmetric posterior-stabilized and cruciate-retaining polyethylene designs have a long track record of high patient satisfaction and longevity in TKA. However, the number and variety of polyethylene inserts and articulations have continued to evolve in an attempt to better replicate native knee kinematics or provide additional constraint. Ultracongruent polyethylene designs have been touted as increasing stability while maintaining the benefits of cruciate-retaining knees. Medial pivot and lateral/dual pivot polyethylene designs were introduced to mimic more normal knee kinematics with regard to femoral rollback. Further, with increasing recognition of knee instability as a cause for persistent symptoms and revision TKA, the utilization of midlevel constraint polyethylene inserts has been increasing, with multiple implant companies offering an insert design with increased constraint for use with a primary femoral component. In this rapidly evolving arena in with a myriad of options available, surgeons should be knowledgeable about the design concepts and their applicable uses for specific patient scenarios. Future research is needed to better understand whether a particular type or design of polyethylene insert and articulation leads to improved patient reported outcomes, improved replication of knee kinematics, and long-term durable implant survivorship.
Lip and Perioral Trauma: Principles of Aesthetic and Functional Reconstruction
Authors: Xie Yanjun , Heft Neal Molly E. , Rudy Shannon F. , Grunebaum Lisa D. , Shaye David A. , Brenner Michael J.
Published: February 2021

Successful management of lip and perioral trauma requires a nuanced understanding of anatomy and surgical techniques. Surgical correction is particularly challenging in instances of tissue loss, due to a narrow tolerance for aesthetic deformity and highly specialized functions of the perioral region, including facial expression, communication, and oral competence. Restoring continuity of the orbicularis oris musculature is critical for dynamic sphincter function of the upper and lower lips. Lip and perioral tissue symmetry are also critical for aesthetic balance, and failure to restore a natural appearance can adversely affect personal identity, with attendant psychological trauma. This discussion of lip and perioral trauma management encompasses lip and perioral anatomy, evaluation of injuries, reconstructive techniques, and prevention and management of complications. Perioral injuries are classified by size, depth, and extent of injury, and the corresponding reconstructive approaches are a function of complexity. These approaches proceed sequentially up rungs of the reconstructive ladder including primary repair, local flaps, grafting, regional flaps, as well as microvascular free tissue transfers. Procedures may be single stage or require multiple stages or subsequent refinement. Regardless of the defect size or location, the guiding principle of repair in the perioral region is restoring natural function and aesthetic appearance. This still-evolving area of facial plastic and reconstructive surgery lends itself to artistry and technical precision, offering opportunities for further innovation to improve the outcomes of patients with lip and perioral trauma.
Designing international organizations for debate? A factor analysis
Authors: Panke Diana , Hohlstein Franziska , Polat Gurur
Published: February 2021

International organizations (IOs) constitute key arenas in which states discuss common issues. Such debates are central prerequisites for taking qualitatively good decisions. Yet researchers have not examined how IOs foster discussion through their institutional provisions. We conduct a factor analysis of institutional rules of 114 IOs which reveals that two ideal types how IOs seek to induce discussion exist: The first type creates room for debate in the negotiation stage of the policy cycle. In contrast, the second type gives member states a strong say in the agenda-setting, thereby facilitating debate. Why do IOs opt for either strategy? A limited policy scope, heterogeneity among actors, and diplomatic socialization increase the probability that IOs place emphasis on debate during negotiations, while a high number of members is the main reason for IOs to promote debate during agenda-setting. These choices reflect the strive of IOs to balance extensive debate with speedy decision-making.
Effect of low-level jet height on wind farm performance
Authors: Gadde Srinidhi N. , Stevens Richard J. A. M.
Published: February 2021

Low-level jets (LLJs) are the wind maxima in the lowest 50 to 1000 m of atmospheric boundary layers. Due to their significant influence on the power production of wind farms, it is crucial to understand the interaction between LLJs and wind farms. In the presence of a LLJ, there are positive and negative shear regions in the velocity profile. The positive shear regions of LLJs are continuously turbulent, while the negative shear regions have limited turbulence. We present large eddy simulations of wind farms in which the LLJ is above, below, or in the middle of the turbine rotor swept area. We find that the wakes recover relatively quickly when the LLJ is above the turbines. This is due to the high turbulence below the LLJ and the downward vertical entrainment created by the momentum deficit due to the wind farm power production. This harvests the jet's energy and aids wake recovery. However, when the LLJ is below the turbine rotor swept area, the wake recovery is very slow due to the low atmospheric turbulence above the LLJ. The energy budget analysis reveals that the entrainment fluxes are maximum and minimum when the LLJ is above and in the middle of the turbine rotor swept area, respectively. Surprisingly, we find that the negative shear creates a significant entrainment flux upward when the LLJ is below the turbine rotor swept area. This facilitates energy extraction from the jet, which is beneficial for the performance of downwind turbines.
Design of modular multi-channel electron spectrometers for application in laser matter interaction experiments at Prague Asterix Laser System
Authors: Krupka M. , Singh S. , Pisarczyk T. , Dostal J. , Kalal M. , Krasa J. , Dudzak R. , Burian T. , Jelinek S. , Chodukowski T. , Rusiniak Z. , Krus M. , Juha L.
Published: February 2021

This paper describes design, development, and implementation of a multi-channel magnetic electron spectrometer for the application in laser–plasma interaction experiments carried out at the Prague Asterix Laser System. Modular design of the spectrometer allows the setup in variable configurations to evaluate the angular distribution of hot electron emission. The angular array configuration of the electron spectrometers consists of 16 channels mounted around the target. The modules incorporate a plastic electron collimator designed to suppress the secondary radiation by absorbing the wide angle scattered electrons and photons inside the collimator. The compact model of the spectrometer measures electron energies in the range from 50 keV to 1.5MeV using ferrite magnets and from 250 keV to 5MeV using stronger neodymium magnets. An extended model of the spectrometer increases the measured energy range up to 21MeV or 35MeV using ferrite or neodymium magnets, respectively. Position to energy calibration was obtained using the particle tracking simulations. The experimental results show the measured angularly resolved electron energy distribution functions from interaction with solid targets. The angular distribution of hot electron temperature, the total flux, and the maximum electron energy show a directional dependence. The measured values of these quantities increase toward the target normal. For a copper target, the average amount of measured electron flux is 1.36 × 1011, which corresponds to the total charge of about 21 nC.
A point-cloud deep learning framework for prediction of fluid flow fields on irregular geometries
Authors: Kashefi Ali , Rempe Davis , Guibas Leonidas J.
Published: February 2021

We present a novel deep learning framework for flow field predictions in irregular domains when the solution is a function of the geometry of either the domain or objects inside the domain. Grid vertices in a computational fluid dynamics (CFD) domain are viewed as point clouds and used as inputs to a neural network based on the PointNet architecture, which learns an end-to-end mapping between spatial positions and CFD quantities. Using our approach, (i) the network inherits desirable features of unstructured meshes (e.g., fine and coarse point spacing near the object surface and in the far field, respectively), which minimizes network training cost; (ii) object geometry is accurately represented through vertices located on object boundaries, which maintains boundary smoothness and allows the network to detect small changes between geometries and (iii) no data interpolation is utilized for creating training data; thus accuracy of the CFD data is preserved. None of these features are achievable by extant methods based on projecting scattered CFD data into Cartesian grids and then using regular convolutional neural networks. Incompressible laminar steady flow past a cylinder with various shapes for its cross section is considered. The mass and momentum of predicted fields are conserved. We test the generalizability of our network by predicting the flow around multiple objects as well as an airfoil, even though only single objects and no airfoils are observed during training. The network predicts the flow fields hundreds of times faster than our conventional CFD solver, while maintaining excellent to reasonable accuracy.
Imprint issue during retention tests for HfO2-based FRAM: An industrial challenge?
Authors: Bouaziz J. , Rojo Romeo P. , Baboux N. , Vilquin B.
Published: February 2021

For ferroelectric random access memory (FRAM) with HfO2-based materials, the wake-up effect and the imprint have to be limited. Here, the electrical behavior of different samples is investigated during retention tests on woken-up samples at room temperature. Retention properties are compared during tests with or without alternations of voltage pulses with opposite signs. First, during retention tests with alternations, the imprint oscillates between two values that are believed to be too high for the reading operation of industrial FRAM memories. This imprint oscillation is not the sole cause of remanent polarization loss. Second, the wake-up effect and retention loss appear to be closely linked. Finally, two retention fitting models are tested: the first one follows a power law t−n and the second one corresponds to a stretched exponential behavior exp(−t/τβ). The data cannot be fitted by the power law at all, while the stretched exponential can fit the data after t>100 s. In fact, the stretched exponential model highlights that the remanent polarization reduction during retention tests can be separated into at least two parts: a behavior for a short period of elapsed time and a behavior after a long period of elapsed time. The origins of this two-part remanent polarization loss behavior are discussed.
Interactions of the interface of immiscible liquids with an impinging vortex ring
Authors: Song Minho , Choi Seongwon , Kim Daegyoum
Published: February 2021

The dynamic behaviors of an interface between two immiscible fluids, which are deformed by a vortex ring impinging normally onto the interface, are experimentally investigated. By varying the strength and size of the vortex ring generated by a piston-cylinder apparatus, several deformation modes of the immiscible interface are identified based on the deforming and rebounding processes and instability of the interface. At a given penetration depth, the profiles of the interfacial deformation shaped as ellipsoidal caps exhibit similarity even for different deformation modes. Geometric quantities that represent the interfacial deformation, such as the maximum penetration depth during the deforming phase and the maximum elevation during the rebounding phase, are closely related to the Froude number. However, the Froude-number range for each deformation mode and the interface profiles at a given Froude number differ by the Bond number because surface tension effects are not negligible in the scale of our model. An empirical dimensionless parameter, which combines the Froude and Bond numbers, is introduced to account for the effects of fluid inertia, gravitation, and surface tension together and is used to quantitatively characterize the interfacial deformation. Moreover, the boundaries between the deformation modes are clearly identified by the new parameter, while they are barely changed by the ratio of piston stroke length to cylinder diameter.