bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of fast square root calculation methods for fixed point microcontroller-based control systems of power electronics
Authors: Dianov Anton , Anuchin Aleksey
Published: June 2020

Square root calculation is a widely used task in real-time control systems especially in those, which control power electronics: motors drives, power converters, power factor correctors, etc. At the same time calculation of square roots is a bottle-neck in the optimization of code execution time. Taking into account that for many applications approximate calculation of a square root is enough, calculation time can be decreased with the price of precision of calculation. This paper analyses existing methods for fast square root calculation, which can be implemented for fixed point microcontrollers. It discusses algorithms’ pros and cons, analyses calculation errors and gives some recommendations on their use. The paper also proposes an original method for fast square root calculation, which does not use hardware acceleration and therefore, is suitable for implementation at a variety of modern Digital Signal Processors, which have high-speed hardware multipliers, but do not have effective dividers. The maximum relative error of the proposed method is 3.36% for calculation without division, and can be decreased to 0.055% using one division operation. Finally, the most promising methods are compared and results of their performance comparisons are depicted in tables. 
Performance analysis on direct torque controlled induction motor drive with varying hysteresis controller bandwidth
Authors: Allirani S. , Subha Lakshmi N. , Vidhya H.
Published: June 2020

The fore most issue in DTC based induction motor drive is its torque ripples. The core objective of this paper is to reduce the electromagnetic torque ripples by varying the hysteresis controller bandwidth. Space Vector Modulation (SVM) based Direct Torque Controlled (DTC) induction motor drive is simulated in MATLAB/SIMULINK environment and its performance is studied with step change in load torque. The influence of hysteresis controller bandwidth on the performance of induction motor drive is analysed in terms of stator flux and electromagnetic torque ripples. The electromagnetic torque response and the stator flux trajectory for different values of hysteresis controller bandwidth are obtained and the results are presented.
Multi-machine transient stability by using static synchronous series compensator
Authors: Salim Nur Ashida , Zain Nur Diyana Shahirah Mohd , Mohamad Hasmaini , Yasin Zuhaila Mat , Aziz Nur Fadilah Ab
Published: June 2020

Transient stability in power system is vital to be addressed due to large disturbances that could damage the system such as load changes and voltage increases. This paper presents a multi-machine transient stability using the Static Synchronous Series Compensator (SSSC). SSSC is a device that is connected in series with the power transmission line and produces controllable voltage which contribute to a better performance in the power system stability. As a result, this research has observed a comparison of the synchronization of a three-phase system during single-phase faults before and after installing the SSSC device. In addition, this research investigates the ability of three different types of controllers i.e. Proportional Integral (PI), Proportional Integral Derivation (PID), and Generic controllers to be added to the SSSC improve the transient stability as it cannot operate by itself. This is because the improvement is too small and not able to achieve the desired output. The task presented is to improve the synchronization of the system and time taken for the voltage to stabilize due to the fault. The simulation result shows that the SSSC with an additional controller can improve the stability of a multi-machine power system in a single phase fault.
Scherbius wind farm based fuzzy SSSC
Authors: Abderrahmane Talebi , Hamza Tedjini
Published: June 2020

The wind is a clean, free, and readily available renewable energy source, it is cost-effective in several regions, it is a domestic source of energy and it is a sustainable source of energy. The SSSC system is a FACTS voltage compensator, it is inserted in series with the electrical transmission line through a coupling transformer, its role is to inject a voltage which allows to influence the active power transmitted. The goal of this paper is to examine the effect of using a wind farm SSSC to improve flexibility of a multi-machine perturbed network.
Model reference self-tuning fractional order PID control based on for a power system stabilizer
Authors: Ghany M. A. Abdel , Shamseldin Mohamed A.
Published: June 2020

This paper presents a novel approach of self-tuning for a Modified Fractional Order PID (MFOPID) depends on the Model Reference Adaptive System (MRAS). The proposed self-tuning controller is applied to Power System Stabilizer (PSS). Takaji-Sugeno (TS) fuzzy logic technique is used to construct the MFOPID controller. The objective of MRAS is to update the five parameters of Takaji-Sugeno Modified FOPID (TSMFOPID) controller online. For different operating points of PSS, MRAS is applied to investigate the effectiveness of proposed controllers. The harmony optimization technique used to obtain the optimal parameters of TSMFOPID controllers and MRAS parameters. For different operating points with different disturbance under parameters variations the simulation results are obtained. This is to show that Self-Tuning of TSMFOPID based on (MRAS) have better performance than the fixed parameters TSMOFOPID controller.
Design and analysis of a novel quasi Z source based asymmetric multilevel inverter for PV applications
Authors: Sankar Deepa , Babu C. A.
Published: June 2020

A novel Quasi Z source (QZS) based Asymmetric Multilevel Inverter for Photovoltaic application is proposed in this paper. It consists of an Impedance source-based dc-dc converter and Asymmetric Multilevel Inverter (AMLI). QZS network can buck/boost the input DC voltage eliminating separate DC-DC boost converter. MLI topology with reduced switches and DC input provide high quality output with large levels. DC input magnitude of the inverter is based on an algorithm. The system ensures high voltage gain, low switching stress, lessened gate circuitry, high reliability and better harmonic profile. Low THD values ensures reduced filter size and hence cost. The theoretical concepts and parameter design of the proposed topology is illustrated in detail. The performance analysis is verified using Matlab/Simulink environment.
Wireless power and data transfer through carbon composite using a common inductive link
Authors: Vu Tuan Anh , Pham Chi Van , Tran William , Pham Anh-Vu , Gardner Christopher S.
Published: June 2020

This paper presents the design and development of an integrated wireless power transfer and data communication system. The power and data transfer share a common inductive link that consists of two identical Helical coils placed on both sides of a carbon composite barrier. Power and data are transferred simultaneously through a 5-mm thick carbon composite barrier without any physical penetration or contact. Power transfer measurements show that the system can deliver 9.7 AC power to the receiving coil with a power transfer efficiency of 36% through the carbon composite barrier. The system achieves a bidirectional half-duplex data communication with the data rate of unit 1.2kbit/s.
The enhancement of power quality for the distribution system via dynamic voltage restorer
Authors: Mohammed Ali Basim , Ariff Mohd Aifaa Mohd
Published: June 2020

This paper represents a new configuration of the dynamic voltage restorer consists of approximate classical sliding mode differentiator (ACSMD) with the terminal sliding mode controller (TSMC) as the nonlinear sliding variable. In this study, the proposed structure of the DVR is utilized to maintain the magnitude of the load voltage at a constant value, maintain the system total harmonic distortion (THD), boost the robustness property and minimize the steady-state error. The power quality has received more interest due to the implementation of various industrial devices and critical loads at the distribution side. Nowadays, the main challenges in power quality in the system are voltage sags/swells, harmonics and voltage imbalance. Various devices are utilized to address these challenges. The dynamic voltage restorer is one of these devices. It is connected in series with the distribution system and injects a proper voltage magnitude to maintain the voltage load at the constant value. In this paper, the DVR model with the ASMF and TSMC is implemented in using MATLAB/Simulink. The proposed controller is evaluated using the standard voltage sag indices.
An approach of controlling the inverter-based generator for use in an islanded microgrid
Authors: Janjornmanit Suchart , Panta Sakorn , Thonglek Vishnu
Published: June 2020

The controls of power generation by the inverter-based generator are proposed in this work. The proposed control adjusts the active power output by varying the phase angle instead of the conventional frequency variation. The benefit of operating the network by a fixed frequency is that it eradicates the problems associated with the frequency deviation. The PID controls with recommended gain adjustment are proposed to control the power generation. The power generation schemes are adapted from the classical power generation by the synchronous generator, where the modes of operation are Swing, PV and PQ mode. The proposed three modes of operation are adequate to operate fully in a small-scale power system such as in an islanded microgrid. A case study of operating the proposed controls in a microgrid by simulation is used to demonstrate the feasibility of implementation of the controls.
Optimal extraction of photovoltaic energy using fuzzy logic control for maximum power point tracking technique
Authors: Chalok Kadhim Hamzah , Tajuddin Mohammad Faridun Naim , Sudhakar Babu Thanikanti , Md Ayob Shahrin , Sutikno Tole
Published: June 2020

In photovoltaic (PV) systems, maximum power point tracking (MPPT) techniques are used to track the maximum power from the PV array under the change in irradiance and temperature conditions. The perturb and observe (P&O) is one of the most widely used MPPT techniques in recent times due to its simple implementation and improved performance. However, the P&O has limitations such as oscillation around the MPP during which time the P&O algorithm will become confused due to rapidly changing atmospheric conditions. To overcome the above limitation, this paper uses the fuzzy logic controller (FLC) to track the maximum power from the PV system under different irradiance, integrates it with a DC-DC boost converter as a tracker. The result of the FLC performance is compared with the traditional P&O method and shows the MPPT algorithm based on FLC ensures continuous tracking of the maximum power within a short period compared with the traditional P&O method. Besides that, the proposed method (FLC) has a faster dynamic response and low oscillations at the operating point around the MPP under steady-state conditions and dynamic change in irradiance.
A new species of Nigrofomes (Hymenochaetales, Basidiomycota) from China

Authors: ZHOU MENG , WU FANG , TIAN XUE-MEI
Published: June 2020

A new poroid fungus, Nigrofomes submelanoporus, from tropical China, is described and illustrated based on morphological characteristics and phylogenetic analysis. The new species is characterized by perennial, resupinate to effused-reflexed, woody-hard and dark gray to almost black basidiocarps, lacerate dissepiments, a monomitic hyphal system, the presence of cystidioles and hyphal pegs, and broadly ellipsoid basidiospores (4–5.1 × 3.1–4.3 µm). Molecular analysis based on ITS sequences demonstrates the phylogenetic position of the new species in Nigrofomes. The discriminating characteristics between the new species and closely related species are discussed.
New species from the nivicola group of Hypogastrura Bourlet, 1839 (Collembola, Poduromorpha, Hypogastruridae) from Canada
Authors: CIPOLA NIKOLAS GIOIA
Published: June 2020

A new Hypogastrura species of the nivicola group from Canada is described and illustrated. The new species is characterized by postantennal organ with outer anterior lobe elongated, head interocular tubercles not prominent, all terga with some extra chaetae, dens dorsally with 8–9 conical, bi- or tridentate spines, and a boat-shaped mucro with subapical tooth. A discussion on the morphology of the nivicola group is given and an identification key for all eight species of this group found in the Nearctic is provided.
The genus Holopothrips Hood, 1914 in Guadeloupe with descriptions of two new species (Thysanoptera, Phlaeothripidae)
Authors: MICHEL BRUNO , ETIENNE JEAN
Published: June 2020

After the revision of the genus Holopothrips provided by Lindner et al. (2018), the specimens of Holopothrips kept in the CIRAD/CBGP collection collected in Guadeloupe were re-examined. Two species previously identified as Holopothrips tenuis and Holopothrips sp. are described here as H. brevisetus sp. n. and H. guadeloupensis sp. n. Holopothrips ananasi is here removed from the list of species reported to Guadeloupe after re-examination of labelled specimens. Information on all the species of Holopothrips found in Guadeloupe, and an identification key to the species of Holopothrips recorded from the Caribbean are provided.
MiR-203 Regulates DJ-1/Phosphatase and Tensin Homologue Deleted on Chromosome Ten/Phosphatidylinositol-3 Kinase/Protein Kinase B Pathway and Affects Proliferation, Apoptosis and Cisplatin Resistance of Ovarian Cancer Cells
Authors: Liu Ping , Wen Jie , Zhao Nannan
Published: June 2020

DJ-1 negatively regulates PTEN and plays a role in tumorigenesis and progression. Abnormal miR-203 expression is associated with ovarian cancer. miR-203 was predicted to have a relationship with DJ-1 3-UTR. Our study assessed miR-203’s role in ovarian cancer cell cisplatin (CDDP)
resistance. The CDDP-resistant cell line SKOV3/CDDP was established and compared with the expression of miR-203 and DJ-1 in the parental SKOV3 cells. SKOV3/CDDP cells were separated into miR-NC group and miR-203 mimic group followed by analysis of DJ-1, PTEN and p-AKT expression, cell apoptosis
and proliferation. There was a targeted relationship between miR-203 and DJ-1 mRNA. miR-203 and PTEN protein expression in SKOV3/CDDP cells was significantly reduced compared to SKOV3 cells with significantly upregulated DJ-1. miR-203 mimic significantly upregulated miR-203, decreased DJ-1
and p-AKT protein expression and elevated PTEN expression along with increased cell apoptosis and reduced cell proliferative ability. Decreased miR-203 expression and increased DJ-1 expression participate in drug resistance in ovarian cancer cells. miR-203 inhibits DJ-1 expression, affects
PTEN-PI3K/AKT signaling, inhibits ovarian cancer cell proliferation and promotes apoptosis, and reduces CDDP resistance.
Isolation and Characterization of Mesenchymal Stem Cells from Chicken Liver
Authors: Liu Xibin , Zhang Shuang , Guan Weijun , Zheng Dong
Published: June 2020

Hepatic mesenchymal stem cells (HMSCs) are multipotent stem cells that is a vital part of the regeneration of hepatocytes after injury. In this study, HMSCs were isolated in embryonic livers from of 12-day-old chick embryo using collagenase, and the primary HMSCs were sub-cultured to
passage. The protein markers of HMSCs, namely CD71, CD29 and CD44, were tested with immunofluorescence and Reverse Transcription-Polymerase Chain Reaction (RT-PCR). The proliferation of HMSCs in different passages was detected using growth curve, which shown a typically sigmoidal. And then,
the pluripotent of HMSCs was analyzed, the results showed that HMSCs could directly induce to differentiate into neural-like cells, adipocytes, and osteoblasts. Our data illustrated that the chick HMSCs have same characteristics to those obtained from other species. The capacity of these cells
for multilineage differentiation shows promise for many potential applications.
Fusion of “You and Me”: Cultural Mixing Promotes Intergroup Psychological Compatibility
Authors: Bao Yan , Zhao Yufang , Xiao Zilun , Liang Fangmei , Wang Weichao , li Bo
Published: June 2020

Previous research has mainly examined individuals’ attitudes to cultural mixing per se, and rarely examined the attitudes to the outgroup involved in cultural mixing. Exposure to ingroup–outgroup cultural mixing may be an indirect intergroup contact, which can promote individuals’ psychological compatibility toward the corresponding cultural outgroup. We measured Chinese Yi undergraduates’ experience of Yi-Tibetan cultural mixing in Study 1 and found it was significantly correlated with psychological compatibility toward Tibetans. We then used a between-subjects design and experimentally manipulated Yi participants’ exposure to cultural mixing to verify the causal effect of exposure to Yi-Dai cultural mixing on psychological compatibility toward Dai (the Yi and Dai are two of the 55 ethnic minorities in China from different provinces and have their own unique culture; Study 2) and the mediating role of perceived connection (Studies 3 and 4). These findings suggest that exposure to cultural mixing facilitates intergroup psychological compatibility, and this beneficial effect is mediated by perceived connection.
A prediction model of thrust force for drilling of bidirectional carbon fiber–reinforced carbon matrix composites
Authors: Shan Chenwei , Zhang Shengnan , Zhang Menghua , Qin Kaifeng
Published: June 2020

Carbon fiber–reinforced carbon matrix composites have been widely used for the manufacturing of thermostructural parts for several industries such as the aerospace and automotive. Drilling is an extremely common method used in the machining of carbon fiber–reinforced carbon matrix composites before assembly. However, their non-homogeneous, anisotropic, and brittle nature make difficult to guarantee the hole quality in drilling. Some severe drilling defects, such as burrs, delamination, and tear, usually occur. In this regard, it is necessary to accurately predict the thrust force in drilling of carbon fiber–reinforced carbon matrix composites. Therefore, in this article, based on the cutting theory of fiber-reinforced polymer composites, an alternative thrust force prediction model for drilling of bidirectional carbon fiber–reinforced carbon matrix composites is proposed. The cutting force of the cutting lips is established by dividing the cutting deformation zone into three regions according to the machined material structure based on the Zhang’s model in cutting of fiber-reinforced polymer. The periodic variation of fiber orientation is considered in detail. The experimental results show that the relative deviations of the predicted and experimental values of the thrust force are less than 14.36%.
Assessment and Modification of General Criminal Attitudes Among Men Who Have Sexually Offended
Authors: Olver Mark E. , Stockdale Keira C. , Simourd David J.
Published: June 2020

General criminal attitudes have been well established as a dynamic risk factor for the origin, maintenance, and continuation of criminal behavior. Guided by the risk–need–responsivity (RNR) framework, this study examined self-reported change on a measure of general criminal attitudes in a sample of incarcerated men who participated in a sexual offense treatment program. Participants were administered the original version of the Criminal Sentiments Scale (CSS) and other measures at pretreatment and posttreatment and followed up in the community an average 14 years post-release. The results demonstrated that CSS total and subscale scores predicted general and violent recidivism, showed convergence with actuarial measures of criminogenic need, and had clinically meaningful associations with responsivity considerations. Pre–post changes on the CSS were associated with decreased general and violent recidivism controlling for pretreatment score and baseline risk. Implications for forensic assessment and correctional intervention are discussed.
The Birth of the Colonia del Carmen in Coyoacán during the Porfiriato (1890-1910): An Ideological Analysis
Authors: Brosseau Esteban García
Published: June 2020

This article examines the birth of the urban development known as Colonia del Carmen, in Coyoacán, from 1890 to 1910, during the Porfirio Díaz Regime, in Mexico. To do so, the main source analyzed here is the Bosquejo Histórico de Coyoacán of Francisco Sosa, one of the most famous Mexican writers and historians of the time. Indeed, although this text is written by this author as an innocuous historical narrative of Coyoacán, the fact that it was specifically written to commemorate the inauguration of the Colonia by Porfirio Díaz and his wife Carmen reveals a lot of the ideological climate that was behind this type of development at the end of the nineteenth century. Contrasting Sosa’s narrative with the official archives related to the development of the Colonia shows how Sosa tried to inscribe the commercial enterprise it represented within the myth of the Pax Porfiriana.
Structural Change and Women’s Employment Potential in Myanmar
Authors: Mueller Valerie , Schmidt Emily , Kirkleeng Dylan
Published: June 2020

We use the Integrated Household Living Conditions Survey to evaluate the extent women are included in Myanmar’s dynamic transformation process and the relative barriers that prohibit their inclusion between 2005 and 2010. Women play an active role in the labor force during a period of massive structural change. Their growing importance is substantiated by their increasing placement in manufacturing jobs near and away from home. Despite their increasing labor force participation, women’s engagement in manufacturing is negatively associated with household welfare. This may be a function of a gender pay gap or reflect households’ inability to substitute the labor of women to complete specific tasks related to household production. Future investments in surveys in Myanmar will improve our ability to identify which factors systematically provide an enabling environment for female labor participation, mobility, and improvements in well-being.
Comparison of Frenotomy Techniques for the Treatment of Ankyloglossia in Children: A Systematic Review
Authors: Khan Usman , MacPherson Jake , Bezuhly Michael , Hong Paul
Published: June 2020

Objective

To compare the effectiveness of conventional (CF), laser (LF), and Z‐plasty (ZF) frenotomies for the treatment of ankyloglossia in the pediatric population.

Data Sources

A comprehensive search of PUBMED, EMBASE, and COCHRANE databases was performed.

Review Methods

Relevant articles were independently assessed by 2 reviewers according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis (PRISMA) guidelines.

Results

Thirty‐five articles assessing CF (27 articles), LF (4 articles), ZF (3 articles), and/or rhomboid plasty frenotomy (1 article) were included. A high level of outcome heterogeneity prevented pooling of data. All 7 randomized controlled trials (RCTs) were of low quality. Both CF (5 articles with 589 patients) and LF (2 articles with 78 patients) were independently shown to reduce maternal nipple pain on a visual analog or numeric rating scale. There were reports of improvement with breastfeeding outcomes as assessed on validated assessment tools for 88% (7/8) of CF articles (588 patients) and 2 LF articles (78 patients). ZF improved breastfeeding outcomes on subjective maternal reports (1 article with 18 infants) only. One RCT with a high risk of bias concluded greater speech articulation improvements with ZF compared to CF. Only minor adverse events were reported for all frenotomy techniques.

Conclusions

Current literature does not demonstrate a clear advantage for one frenotomy technique when managing children with ankyloglossia. Recommendations for future research are provided to overcome the methodological shortcomings in the literature. We conclude that all frenotomy techniques are safe and effective for treating symptomatic ankyloglossia.
Validation of a Novel, Multidomain Head and Neck Cancer Appearance‐ and Function‐Distress Patient‐Reported Outcome Measure
Authors: Graboyes Evan M. , Hand Brittany N. , Ellis Mark A. , Huang Andrew T. , Nilsen Marci L. , Pipkorn Patrik , Marsh Courtney H. , Maurer Stacey , Day Terry A. , Sterba Katherine R.
Published: June 2020

Objectives

Distress with self‐perceived changes in appearance and function can result in body image disturbance (BID), which is common in head and neck cancer (HNC) survivors and a major source of psychosocial morbidity. To address the lack of psychometrically sound patient‐reported outcome measures (PROMs) of HNC‐related BID, we aim to create and validate the Inventory to Measure and Assess imaGe disturbancE–Head & Neck (IMAGE‐HN).

Study Design

Survey study.

Setting

Multiple academic centers.

Subjects and Methods

Following item development, HNC survivors from 4 academic centers completed the IMAGE‐HN. Item responses were psychometrically analyzed using confirmatory factor analysis (CFA) and Rasch analysis.

Results

Item development resulted in a 31‐item PROM consisting of 5 individual domains and a global domain. In total, 305 HNC survivors of diverse ages, HNC subsites, and reconstructive paradigms completed the initial items. After removal of 3 items for local dependence, CFA confirmed the unidimensionality and local independence (item residual correlations <|0.20|) for each domain. Rasch analysis indicated acceptable fit (infit and outfit mean squares <2.0), monotonicity of all rating scale categories, and low person misfit (<4%). Person separation indices and person reliability were adequate for each domain except appearance concealment, which was removed (4 items). This resulted in the IMAGE‐HN, a psychometrically acceptable 24‐item PROM of HNC‐related BID consisting of a global scale and 4 subscales measuring unique constructs and comprised independent items.

Conclusions

IMAGE‐HN is a novel, psychometrically sound, multidomain PROM of HNC‐related BID for use in clinical and research settings.
Implantable Drug Reservoir Devices for Inner Ear Delivery of Pharmacotherapeutics
Authors: Kita Ashley , Saldate Johnny , Chang Courtney , Chellappa Nitika , Jong Jeremy , Matsuda Riley , Schmidt Andrew , Shih Brandon , Shafqat Iram , Schoettler Kari , Acharya Shiv , Seidlits Stephanie , Hoffman Larry
Published: June 2020

Objective

Cisplatin is a platinum‐based chemotherapeutic drug that secondarily induces toxicity in inner ear sensory epithelia, contributing to auditory and vestibular dysfunction. We describe the creation of a drug reservoir device (DRD) to combat this ototoxicity for the duration of chemotherapy. As ototoxic side effects of chemotherapy may limit an oncologist’s ability to prescribe first‐line agents such as cisplatin, mitigating such devastating effects through prolonged topical therapy would be tremendously valuable.

Study Design

We investigated (1) the ability of an electrospun polylactic acid DRD to provide prolonged delivery of the posited otoprotectant metformin and (2) the development of an in vitro model utilizing Sh‐Sy5y human neuroblastoma cells to assess the efficacy of metformin in reducing cisplatin‐induced toxicity.

Setting

Neurophysiology laboratory.

Methods

Basic science experiments were performed to assess DRD properties and metformin’s effects on cisplatin toxicity in culture.

Results

We found that DRDs with increasing polylactic acid concentrations exhibited metformin release for up to 8 weeks. In modeling elution across the round window in vitro, continued elution of metformin was observed for at least 6 weeks, as quantified by spectrophotometry. Unfortunately, metformin did not exhibit protective efficacy in this model using Sh‐Sy5y cells.

Conclusion

While metformin was not found to be protective in Sh‐Sy5y cells, these results suggest that an electrospun DRD can provide a tailorable drug delivery system providing medication for the duration of chemotherapy treatment. This represents a novel drug delivery system and efficacy screening assay with broad clinical applications in personalized delivery of inner ear therapies.
SARS‐CoV‐2 Infection in Health Care Workers: Cross‐sectional Analysis of an Otolaryngology Unit
Authors: Paderno Alberto , Fior Milena , Berretti Giulia , Schreiber Alberto , Grammatica Alberto , Mattavelli Davide , Deganello Alberto
Published: June 2020

The restart of routine in‐ and outpatient activity in the COVID‐19 postepidemic peak needs to be carefully planned in light of specific patterns of viral diffusion. We evaluated SARS‐CoV‐2 serology in the entire personnel of a COVID‐19‐free otolaryngology department in a highly affected area. The aim was to determine the prevalence of SARS‐CoV‐2 positivity among staff to clarify the impact of different risk factors for infection. The entire staff of the otolaryngology unit was tested for SARS‐CoV‐2 serology. Symptomatic staff members were tested with nasal/pharyngeal swabs. All answered a survey focused on the number of in‐ and extrahospital positive contacts and type of activities in the unit. Five (9%) were positive for SARS‐CoV‐2 infection. The only variable associated with a higher risk of infection was the number of extrahospital contacts without personal protective equipment (P =. 008). Our study shows that in non‐COVID‐19 departments, the use of adequate personal protective equipment leads to low rates of infection among health care workers. The prevalent risk of infection was related to extrahospital contact.
Rhinologic Practice Special Considerations During COVID‐19: Visit Planning, Personal Protective Equipment, Testing, and Environmental Controls
Authors: Howard Brittany E. , Lal Devyani
Published: June 2020

As rhinologists return to practice amid SARS‐CoV‐2, special considerations are warranted given the unique features of their subspecialty. Rhinologist manipulation of nasal tissue, proximity, and frequent aerosol‐generating procedures (AGPs) create high risk for infection transmission. There are 4 areas of special consideration to mitigate risk: (1) previsit planning for risk stratification/mitigation, (2) appropriate personal protective equipment, (3) preprocedural testing, and (4) environmental controls. During previsit planning, risk factors of the patient and procedures are considered. High‐risk AGPs are identified by duration, proximity, manipulation of high–viral load tissue, and use of powered instrumentation. Appropriate personal protective equipment includes selection of respiratory and eye protection. COVID‐19 testing can screen for asymptomatic carriers prior to high‐risk procedures; however, alternative testing methods are required in rhinologic patients not eligible for nasopharyngeal testing due to nasal obstruction or skull base defects. Last, AGPs in rhinologic practices require considerations of room air handling and environmental controls.
Exploring the depths of second language processing with eye tracking: An introduction
Authors: Godfroid Aline , Winke Paula , Conklin Kathy
Published: June 2020

In this paper, we review how eye tracking, which offers millisecond-precise information about how language learners orient their visual attention, can be used to investigate a variety of processes involved in the multifaceted endeavor of second language acquisition (SLA). In particular, we review the last 15 years of research in SLA, in which applied linguists have exploited the information gleaned from eye-tracking metrics to advance the field. As we explain, eye-tracking researchers within SLA have diversified which aspects of SLA they investigate and are entering new territory by pairing eye-tracking metrics with other data-collection methods for data-triangulation purposes. Eye tracking in SLA is also an inherently interdisciplinary endeavor, for which research partnerships with computer scientists hold special promise in the areas of automated language assessment and the evaluation of cognitive functioning and processing. We describe how the papers in this special issue on eye tracking in Second Language Research push the boundaries by: (a) ensuring greater standardization of how eye tracking is used in SLA (Godfroid and Hui, 2020); (b) embedding eye-tracking metrics within a mixed-methods design for more valid and complete data interpretation (Andringa, 2020; Michel et al., 2020); (c) using eye trackers to investigate the nuanced differences in cognitive processes involved across multimodal input and feedback types in SLA (Conklin et al., 2020; McDonough et al., 2020).
Exploring Coach–Teacher Interactions Within a Practice-Based Coaching Partnership
Authors: Shannon Darbianne K. , Snyder Patricia A. , Hemmeter Mary Louise , McLean Mary
Published: June 2020

Professional development (PD), which includes coaching, has demonstrated the capacity to affect preschool teachers’ use of evidence-based practices. The present study explored how coaches facilitated conversations within practice-based coaching (PBC) partnerships. A direct behavioral observation coding system was developed to investigate (a) the proportion of time spent in different conversational foci, including who initiated the conversation; (b) coach verbal behaviors; and (c) whether the conversation foci, initiations, and coach verbal behavior changed across three occasions for seven coach–teacher dyads. Results from the present study indicate coaches spent the largest proportion of time engaging in conversations with teachers focused on reflection and feedback, followed by goal setting and action planning. The coaches used verbal behaviors (supportive and constructive feedback, clarifying questions) as required by the coaching protocol across all sampled occasions. Variation in conversation foci, initiations, and coach verbal behavior across three sampled occasions was evident.
Effects of a single dose of vitamin D in septic children: a randomized, double-blinded, controlled trial
Authors: Wang Yu , Yang Zhongwen , Gao Li , Cao Zhenfeng , Wang Qianhan
Published: June 2020

Objective

To assess the effects of a single dose of vitamin D on 25-hydroxyvitamin D (25OHD) levels and clinical outcomes in children with vitamin D deficiency (VDD) and sepsis.

Methods

In this randomized, controlled trial, eligible children with VDD and sepsis were assigned to receive one dose of 150,000 IU of cholecalciferol or placebo. Serum concentrations of 25OHD, angiotensin-II (Ang-II), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed at baseline and 8 days after treatment. The cardiovascular Sequential Organ Failure Assessment (cv-SOFA) score, septic shock incidence, duration of ventilation, and mortality were also examined.

Results

One hundred nine participants fulfilled the study requirements. The two groups had comparable baseline characteristics. Ang-II, IL-6, and TNF-α concentrations were all reduced after vitamin D supplementation. Furthermore, the cv-SOFA score (1.76 ± 0.8 vs. 2.3 ± 1.1) and incidence of septic shock (7% vs. 20%) were lower in the treatment group than in the control group. The duration of ventilation and mortality rates did not differ between two groups.

Conclusions

A single dose of vitamin D improved 25OHD levels and the incidence of septic shock in children with VDD and sepsis.
Safety and efficacy of transperitoneal laparoscopic nephron sparing surgery in patients with previous abdominal surgery
Authors: Manno Stefano , Dell’Atti Lucio , Cicione Antonio , Spasari Angelo
Published: June 2020

Objective:

The aim of this study is to assess the safety and feasibility of the transperitoneal laparoscopic approach during nephron sparing surgery in patients with previous abdominal surgery.

Patients and methods:

We retrospectively analyzed patients undergoing transperitoneal laparoscopic partial nephrectomy for renal masses. All patients had received a diagnosis of cT1a renal exophytic mass (⩽5 cm). Patients were divided into two groups, those with and without previous abdominal surgery. Patients with solitary kidney or major previous abdominal surgery were excluded in this study. The operative time, estimated blood loss, length of stay, surgical complications, and positive surgical margins were recorded to compare outcomes among two groups.

Results:

Of the 157 patients who were included in our study, 71 (45.3%) had a history of abdominal surgery (Group 1), while the remaining 86 (54.7%) had not (Group 2). Cholecystectomy was the most common previous surgery performed near the renal fossa. Patients with previous abdominal surgery experienced increased operative time (111.5 vs 83.2 min; p = 0.001). However, no statistically significant difference was found in estimated blood loss (122.1 vs 114.4 mL; p = 0.363), length of stay (4.1 vs 3.8 days; p = 0.465), rate of conversion to open surgery (2.8% vs 2.3%; p = 0.234), and rate of complications ( p = 0.121). However, operative time ( p = 0.003) and length of stay ( p < 0.001) were greater in patients with versus those without previous open cholecystectomy.

Conclusion:

Our results suggest that laparoscopic partial nephrectomy after minor previous abdominal surgery is safe and feasible in selected patients affected by renal masses with low nephrometry score. However, previous cholecystectomy results in an increased risk of conversion to open surgery and longer hospital stay in patients undergoing right laparoscopic partial nephrectomy.
Associations Between Variations in Breast Anatomy and Early Breastfeeding Challenges
Authors: Ventura Alison K. , Lore Brittany , Mireles Olga
Published: June 2020

Background

Mothers with anatomic variability (e.g., shorter, wider nipples; denser areolas) may experience breastfeeding challenges disproportionately.

Research aim

To examine whether variations in breast anatomy are associated with risk for early breastfeeding challenges.

Methods

Participants included mothers < 6 weeks postpartum. Nipple base width, nipple length, and areolar density were measured on the right and left breast separately. Experiences with early breastfeeding challenges were determined through a combination of maternal report and clinical assessment.

Results

Participants ( N = 119) had an average nipple diameter of 23.4 ( SD = 3.0) mm for left nipples and 23.5 ( SD = 3.0) mm for right nipples (range = 10–34 mm). Average nipple length was 8.5 ( SD = 3.2) mm for left breasts and 9.1 ( SD = 3.2) mm for right breasts (range = 5–20 mm); 35% of participants had dense areolas on the left breast and 36% had dense areolas on the right breast. The combination of wider and longer nipples was associated with greater risk for difficulties with latch; the combination of wider nipples and denser areolas was associated with greater risk for sore nipples. For participants with more dense areolas, shorter and wider nipples were associated with greater risk for low milk supply and slow infant weight gain. For participants with less dense areolas, longer and wider nipples were associated with greater risk for low milk supply and slow infant weight gain.

Conclusion

Further research is needed to understand how measures of breast anatomy can be used to guide targeted intervention efforts.
Perceived Patient Pain and Spousal Caregivers’ Negative Affect: The Moderating Role of Spouse Confidence in Patients’ Pain Management
Authors: Nah Suyoung , Martire Lynn M. , Zhaoyang Ruixue
Published: June 2020

Objectives: This study examined whether older patients’ greater daily pain perceived by their spouses was associated with spouses’ higher daily negative affect. We further investigated whether spouses’ lower confidence in patients’ ability to manage pain exacerbated the daily association between perceived patient pain and spouses’ negative affect. Method: We used baseline interviews and a 22-day diary of knee osteoarthritis patients and their spouses ( N = 144 couples). Multilevel models were estimated to test hypotheses. Results: Daily perceived patient pain was not associated with spouses’ daily negative affect. However, spouse confidence significantly moderated the association. Only spouses with lower confidence in patients’ pain management experienced higher negative affect on days when they perceived that patients’ level of pain was higher than usual. Discussion: Findings suggest that spousal caregivers’ lack of confidence in patients’ pain management may be a risk factor for spouses’ affective distress in daily life.
Improved CFD prediction of flows past simplified and real-life automotive bodies using modified turbulence model closure coefficients
Authors: Bounds Charles Patrick , Zhang Chunhui , Uddin Mesbah
Published: June 2020

In spite of its shortcomings, faster turnaround time and cost-effectiveness make the Reynolds-averaged Navier–Stokes modeling approach still a popular and widely used methodology in many industrial applications, including the automotive industries in general, but the motorsports sector in particular. Existing literature suggests that all Reynolds-averaged Navier–Stokes models generally fail to predict pressure and velocity flow fields with a reasonable accuracy, especially in the vehicle wake region. Recent numerical works suggest that, when using two-equation eddy viscosity turbulence models, improved correlation between the experiment and computational fluid dynamics is not achievable through only mesh refinements or adding additional corrective terms in the turbulence transport equations, and additional efforts are necessary for better predictions. In this backdrop, the prediction improvement strategy adopted in this paper is based on the realization that the turbulence model closure coefficients are normally specified as constants and their values are determined from either a single observation or a simple functional form is assumed and that these coefficients are constructed and/or constrained to behave correctly in extremely limiting circumstances. Subsequently, this study investigated the influence of a few selected turbulence model closure coefficients on the veracity of computational fluid dynamics predictions by analyzing simulations run with turbulence model closure coefficient values that were different from the commonly used default ones. This was done by first investigating the individual effect of each model parameters on the prediction veracity, and then a combination of model closure coefficient values was formulated in order to obtain a prediction with the best experimental correlation. This procedure was applied to four different test objects which include NACA 4412 airfoil at 12° angle of attack, the 25 and 35° slant angle Ahmed body, and a full-scale sedan type passenger vehicle. The shear-stress transport [Formula: see text] was chosen as the turbulence model because of its popularity in automotive applications. It was observed that, irrespective of the test model, the computational fluid dynamics predictions are somewhat independent of some closure coefficients, while the prediction showed strong dependencies on certain model constant values, especially those in the dissipation equation. The present study demonstrated that, by using a modified set of closure coefficient values, very well correlated computational fluid dynamics predictions were possible. The findings from this study simply reiterate a 20-year-old conclusion by Stephen Pope that the closure coefficients for a model are not static and universal but instead are dynamic and must be calibrated for specific flow situations.
Assessment of Lean Supply Chain Practices in Indian Automotive Industry
Authors: Kumar Singh Rohit , Modgil Sachin
Published: June 2020

The purpose of this study is to explore the effect of lean practices on performance measures in the automotive industry and identify the lean criteria that can have significant impact on automotive supply chain. The identified lean practices can serve as a template to enhance the performance of a supply chain. The present study offers a multi-criteria decision-making approach to identify the effective performance practices in automotive lean supply chain. The decision-making trial and evaluation laboratory (DEMATEL) was applied on a matrix of observed values and the actual effect of proposed practices was observed. Further it was confirmed with the help of fuzzy- Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR; that means multicriteria optimization and compromise solution, with pronunciation). The criteria which had the most impact are proposed for achieving the future goals of leanness. It was found that among the lean criteria considered, quality management, information management and customer management practices influence the key performance measures more than others. Although DEMATEL and fuzzy-VIKOR were applied for situation leading to setting up of priorities of factors that considered affecting automotive manufacturer, the proposed methodology can be applied in diverse industrial settings. The present study may help decision-makers to device the appropriate strategy in identifying major practices that influence the lean supply chain.
Development and Validation of an Empirical Model to Study the Mediating Role of Empathic School Leadership in the Motivation of High School Students in India
Authors: Roy Debarshi
Published: June 2020

Emotionally fragile organizations like schools require human elements to be treated with utmost care. Most schools in India are managed by a strictly hierarchical organizational structure with the head of the school at the top. In such organizational structures, the head decides the design, nature, and direction of the various school processes. It is within this context that this study explores the two important dimensions of leadership and empathy in conjunction with each other. While the capability to feel and share the feelings of others has been regarded as an essential leadership quality, school leadership brings forth a unique and potent dimension to the concept of empathic leadership. This study explores the role of empathic school leadership in motivating students. A random sample of 297 students was administered a questionnaire. The results were analysed and a model with empathic–leadership as a mediator for student motivation was developed and validated using path analysis. Further, the instrument used was validated with confirmatory factor analysis for use as a tool to measure empathy-driven leadership in Indian schools. This instrument might help in introducing the concept of leadership–empathy audit in Indian schools.
The Associations Among Teacher Discrimination, Parents’ and Peer Emotional Supports, and African American Youth’s School Bonding
Authors: Kyere Eric , Karikari Isaac , Teegen Bettina C.
Published: June 2020

Drawing on research about the positive benefits of school bonding on youth mental health, academic and overall well-being, and the inequities African American youth face in education, this study examined the associations among teacher discrimination, parents’ and peer emotional support, and African American youth school bonding. Using data from the National Survey of American Life Adolescent Supplement (NSAL-A), findings suggest that teacher discrimination negatively affects African American youth’s school bonding. In addition, while parents’ and peer emotional supports are positively associated with youth’s school bonding, and offset some of the negative effects of teacher discrimination on African American youth’s school bonding, these supports may not be enough to help youth realize the maximum benefits of school bonding, especially in the context of teacher discrimination. Implications for social work practice with African American youth and families are discussed.