bluuebunny/crossref_metadata_2025 huggingface dataset:
Two papaya MYB proteins function in fruit ripening by regulating some genes involved in cell‐wall degradation and carotenoid biosynthesis
Authors: Fu Changchun , Chen Hangjun , Gao Haiyan , Lu Yin , Han Chao , Han Yanchao
Published: May 2020

BACKGROUND

MYB transcription factors (TFs) are common in plants and play important functions in growth and development, including fruit development and ripening. However, the role of MYB proteins in papaya ripening (fruit ripening and carotenoid biosynthesis) remains unclear.

RESULTS

Two MYB genes were cloned from papaya pulp. They were named CpMYB1 (MYB44‐like) and CpMYB2, and belong to the S22 subgroup of the R2R3‐MYB family. Their expression levels decreased during fruit ripening. Subcellular localization analysis showed that both CpMYB1 and CpMYB2 were nuclear proteins, indicating that they might function in the nucleus. Moreover, CpMYB1 and CpMYB2 could bind to the promoters of cell‐wall degradation genes (CpPME1, CpPME2, and CpPG5) and carotenoid biosynthesis genes (CpPDS2, CpPDS4, and CpCHY‐b). Further research found that both CpMYB1 and CpMYB2 were transcriptional repressors, and they could suppress the activities of the promoters of CpPME1, CpPME2, CpPG5, CpPDS2, CpPDS4, and CpCHY‐b.

CONCLUSION

These results indicated that MYB TFs CpMYB1 and CpMYB2 might have a function in papaya fruit softening and carotenoid accumulation by regulating cell‐wall degradation and carotenoid biosynthesis related genes, which provide a new view about the role of MYB TFs in fruit ripening. © 2020 Society of Chemical Industry
Volatile compounds of a pumpkin (Cucurbita moschata) purée processed by high pressure thermal processing
Authors: García‐Parra Jesús , González‐Cebrino Francisco , Ramírez Rosario
Published: May 2020

BACKGROUND

The changes in the volatile profile of a pumpkin (Cucurbita moschata, Duch.) purée processed by high pressure thermal (HPT) processing at different pressure and initial temperature intensities (300, 600, 900 MPa and 60, 80 °C, respectively) was evaluated. Headspace solid‐phase microextraction (HS‐SPME) technique was used for the extraction and concentration of volatile compounds and the analysis was performed by gas chromatography–mass spectrometry (GC–MS).

RESULTS

Alcohols were the volatile compounds most abundantly isolated in the headspace of pumpkin purée (control and processed purées had ranges between 43 and 56%), followed by aldehydes (14–28%), hydrocarbons (8–13%) and terpenes (7–10%). Lipid oxidation, Maillard reaction and carotenoids degradation were the main chemical routes of formation of volatile compounds after HPT processing. Initial temperature or pressure intensity of HPT processing, within the ranges tested in this study, did not affect the initial levels of volatile compounds of pumpkin purée.

CONCLUSION

HPT processing is an effective technology for the preservation of the original aroma of low acid vegetables such as pumpkin. © 2020 Society of Chemical Industry
Determination of glycosylation degree for glycoconjugate vaccines using a solid‐phase extraction combined with liquid chromatography and tandem mass spectrometry method
Authors: Long Zhen , Li Maoguang , Dahl Jeffrey , Guo Zhimou , Li Yanan , Hao Hongyuan , Li Yueqi , Li Changkun , Mao Qiqi , Huang Taohong
Published: May 2020

In this study, a solid‐phase extraction with liquid chromatography and tandem mass spectrometry method was developed to determine the degree of glycosylation of glycosylation sites and the ratio of free carrier protein to total carrier protein for glycoconjugate vaccines. To remove and enrich the glycosylated peptides, a solid‐phase extraction method was developed, optimized, and hyphenated to liquid chromatography−tandem mass spectrometry. The developed solid‐phase extraction with liquid chromatography−tandem mass spectrometry method was shown to possess a wide linear dynamic range (0.03−100 μg/mL), a high sensitivity (0.03 μg/mL for CRM197), good interday and intra‐day precision (relative standard deviation of peak area < 3.3%), and good recoveries from vaccine matrix (90−105%). Finally, the method was utilized to determine the degree of glycosylation and free carrier protein to total carrier protein ratio for pneumococcal conjugate vaccines and meningococcal vaccines. For quality evaluation of glycoconjugate vaccines, the method could provide more information than the traditional size exclusion chromatography method. Fourteen and twelve reported glycosylation sites for CRM197‐ and tetanus toxin‐based vaccines can be detected, respectively.
Qualitative analysis of enzymatic and chemical depolymerized low molecular weight heparins by UHPLC coupled with electrospray ionization quadrupole time‐of‐flight‐mass spectrometry
Authors: Sadowski Radosław , Gadzała‐Kopciuch Renata , Buszewski Bogusław
Published: May 2020

Complete heparin digestion with heparin lyase I and II results in a mixture of hexasaccharides and tetrasaccharides with 3‐O‐sulfo group‐containing glucosamine residues at their reducing ends. Because these tetrasaccharides are derived from antithrombin III‐binding sites of heparin, we examined whether this method could be applied to estimate the anticoagulant activity of heparin. Therefore, this paper presents a new low molecular weight heparin sample preparation method–chemical depolymerization. Qualitative analysis of the studied compounds and a comparison of their composition are an important contribution to the structural analysis of low molecular weight heparins, which has not been fully conducted so far. Qualitative on‐line liquid chromatography–mass spectrometric analysis of these resistant oligosaccharides is also described in this paper.
Strategies in developing high‐throughput liquid chromatography protocols for method qualification of pharmacopeial monographs
Authors: Kresge Glenn A. , Grosse Sylvia , Zimmer Alexis , Grinias Kaitlin M. , De Pra Mauro , Wong Jenny‐Marie T. , Steiner Frank , Grinias James P.
Published: May 2020

Method qualification is a key step in the development of routine analytical monitoring of pharmaceutical products. However, when relying on published monographs that describe longer method times based on older high‐performance liquid chromatography column and instrument technology, this can delay the overall analysis process for generated drug products. In this study, high‐throughput ultrahigh pressure liquid chromatography techniques were implemented to decrease the amount of time needed to complete a 24‐run sequence to identify linearity, recovery, and repeatability for both drug assay and impurity analysis in 16 min. Multiple experimental parameters were tested to identify a range of experimental settings that could be used for the sequence while still maintaining this fast analysis time. The full sequence was replicated on a different system and with different columns, further demonstrating its robustness.
Mortality and Institutionalization After Percutaneous Endoscopic Gastrostomy in Parkinson's Disease and Related Conditions
Authors: Brown Lisa , Oswal Michelle , Samra Amrit‐Deep , Martin Hannah , Burch Nicola , Colby Joe , Lindahl Andrea , Skelly Rob
Published: May 2020

Background

Percutaneous endoscopic gastrostomy (PEG) can facilitate feeding and medication administration in dysphagic patients with Parkinson's disease and related disorders. Information on survival, institutionalization, and complications post PEG might inform feeding decisions.

Method

A total of 93 patients with Parkinson's disease and related disorders were identified by review of PEG registers and by searching the administrative databases in 2 large UK university hospitals (2005–2017); 83 case notes were available for retrospective review. Care processes and outcomes were assessed.

Results

The following were the diagnoses: 58 (70%) had Parkinson's disease, 10 (12%) had progressive supranuclear palsy, 5 (6%) had multiple system atrophy, 3 (4%) had dementia with Lewy bodies, and 7 (8%) had vascular parkinsonism. The median age was 78 years (interquartile range 72–82); 29 (35%) were women. Care processes included a future care plan in place prior to admission for 18 patients (22%), and PEG was placed during emergency admission in 68 patients (82%). The outcomes included median survival at 422 days; 30‐day mortality rate was 6% (5 patients); and of 56 patients admitted from home, 18 (32%) were discharged to institutions (nursing or care homes). The most common complication was aspiration pneumonia for 18 (22%) of patients. Age, sex, diagnosis, admission type, comorbidities, and place of residence did not predict survival. Discharge to own home and follow‐up by the home enteral feeding team were associated with longer survival.

Conclusion

We recommend markers of advanced disease should prompt advanced care planning. Discussions about PEG feeding should include information about post‐PEG survival, complications, and risk of institutionalization. Further research is needed on quality‐of‐life post PEG and ways to reduce aspiration pneumonia. All PEG patients should have nutrition team follow‐up.
A comparative Fourier analysis of discontinuous Galerkin schemes for advection–diffusion with respect to BR1, BR2, and local discontinuous Galerkin diffusion discretization
Authors: Ortleb Sigrun
Published: May 2020

This work compares the wave propagation properties of discontinuous Galerkin (DG) schemes for advection–diffusion problems with respect to the behavior of classical discretizations of the diffusion terms, that is, two versions of the local discontinuous Galerkin (LDG) scheme as well as the BR1 and the BR2 scheme. The analysis highlights a significant difference between the two possible ways to choose the alternating LDG fluxes showing that the variant that is inconsistent with the upwind advective flux is more accurate in case of advection–diffusion discretizations. Furthermore, whereas for the BR1 scheme used within a third order DG scheme on Gauss‐Legendre nodes, a higher accuracy for well‐resolved problems has previously been observed in the literature, this work shows that higher accuracy of the BR1 discretization only holds for odd orders of the DG scheme. In addition, this higher accuracy is generally lost on Gauss–Legendre–Lobatto nodes.
Numerical analysis of tunable defect mode in cylindrical photonic crystals configuration
Authors: El‐Naggar Sahar A. , Nguyen Truong K. , Dhasarathan Vigneswaran
Published: May 2020

In contrast to most of the previous publications that has addressed the dependency of the defect mode on temperature in planner one‐dimensional photonic crystal, we study this dependency in cylindrical photonic crystal taking into consideration both thermal‐optical and thermal expansion effects. Our analysis, based on the cylindrical transfer matrix, is conducted for both types of polarized electric and magnetic waves. Our structure is composed of arrays of cylindrical coaxial shells of TiO2 and Al2O3 with single defect layer. Numerical results show that the defect mode's wavelength can be effectively tuned, following a linear relation, by changing the temperature for both types of polarized waves. In addition, the peak transmittance is dependent on the number of periods and the starting inner radius. Moreover, decreasing the inner radius is associated with separation between the two polarizations.
Clinical correlates of fatigue in chronic inflammatory demyelinating polyneuropathy
Authors: Lawley Andrew , Abbas Ahmed , Seri Stefano , Rajabally Yusuf A.
Published: May 2020

Introduction

Fatigue is a recognized manifestation of immune‐mediated neuropathies, but its causes and implications are unclear. In this study, we explored the correlates of fatigue among a number of clinical parameters in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) to better understand potential contributing factors and resulting consequences.

Methods

Twenty‐six clinically stable patients with CIDP underwent assessments of motor and sensory function, disability, quality of life, and depression and anxiety. Experienced fatigue was assessed by using the Rasch‐built Fatigue Severity Scale and the Checklist of Individual Strength.

Results

The two fatigue scales provided evidence of significant intercorrelation. Only depression scores and grip strength predicted experienced fatigue levels in multivariate regression analyses. Fatigue scores inversely correlated with strength, sensory, disability, and quality of life scores.

Discussion

Experienced fatigue is likely multifactorial in CIDP, with both physical and neuropsychiatric components. Fatigue is associated with lower functional and quality‐of‐life outcomes in CIDP.
Prospects of neural crest‐derived cells from oral and dentofacial tissues for application in regenerative medicine
Authors: Suzawa Tetsuo , Yoshida Hiroshi , Takahashi Masahiro , Itose Masakatsu , Takimoto Reiko , Sasama Yuji , Tanaka Motohiro , Ikezaki Kaori , Shirora Tatsuo , Maki Koutaro , Kamijo Ruytaro
Published: May 2020

During vertebrate development, neural crest cells arise in the dorsal region of the fusing neural tube, then migrate extensively across the embryonic body to differentiate into various cell types. In adults, subsets of neural crest‐derived cells (NCDCs) reside as stem cells and are considered useful as cell sources for autologous cell therapy. Previous studies have suggested that these NCDC subsets persist into adulthood in mammals, especially those within dentofacial compartments. We have found NCDCs in a wide variety of tissues, including palate, gingiva, and tongue, as well as hair follicles, submandibular glands, and buccal mucosa in adult mice. NCDCs from buccal mucosa can also form neurosphere‐like structures that have a capability to differentiate into osteoblasts. These findings indicate that NCDCs reside in various adult oral and dentofacial regions, and possess potential to differentiate into osteoblastic cells, thus suggesting that those in adults may be a useful source for bone regeneration strategies. In recent years, several researchers have reported regeneration experiments using NCDCs obtained from oral and dentofacial tissues. Here, we review findings related to the distribution of NCDCs, with focus on the oral and dentofacial regions, as well as the future prospects of NCDC‐based regenerative therapies.
Antenatal corticosteroids and outcomes in gastroschisis: A multicenter retrospective cohort study
Authors: Carnaghan Helen , James Catherine P. , Charlesworth Paul B. , Ghionzoli Marco , Pereira Susana , Elkhouli Mohamed , Baud David , De Coppi Paolo , Ryan Greg , Shah Prakesh S. , Davenport Mark , David Anna L. , Pierro Agostino , Eaton Simon ,   Gastroschisis Study Group
Published: May 2020

Objective

In gastroschisis, there is evidence to suggest that gut dysfunction develops secondary to bowel inflammation; we aimed to evaluate the effect of maternal antenatal corticosteroids administered for obstetric reasons on time to full enteral feeds in a multicenter cohort study of gastroschisis infants.

Methods

A three center, retrospective cohort study (1992‐2013) with linked fetal/neonatal gastroschisis data was conducted. The primary outcome measure was time to full enteral feeds (a surrogate measure for bowel function) and secondary outcome measure was length of hospital stay. Analysis included Mann‐Whitney and Cox regression.

Results

Of 500 patients included in the study, 69 (GA at birth 34 [25‐38] weeks) received antenatal corticosteroids and 431 (GA at birth 37 [31‐41] weeks) did not. Antenatal corticosteroids had no effect on the rate of reaching full feeds (Hazard ratio HR 1.0 [95% CI: 0.8‐1.4]). However, complex gastroschisis (HR 0.3 [95% CI: 0.2‐0.4]) was associated with an increased time to reach full feeds and later GA at birth (HR 1.1 per week increase in GA [95% CI: 1.1‐1.2]) was associated with a decreased time to reach full feeds.

Conclusion

Maternal antenatal corticosteroids use, under current antenatal steroid protocols, in gastroschisis is not associated with an improvement in neonatal outcomes such as time to full enteral feeds or length of hospital stay.
Retracted: Influence of organic montmorillonite nanoparticles on the microstructures and thermal and tribological properties of polyethersulfone and polytetrafluoroethylene composites
Authors: Yan Shicheng , Xue Yahong , Wang Zhanchao , Wang Guilian , Wang Shoujun
Published: May 2020

Because of high wear rate and low thermal deformation temperature, the generalization and application of polytetrafluoroethylene (PTFE) in the field of tribology is restrained to a certain extent. In order to improve the wear resistance and thermal stability of this self‐lubricating polymer, organic montmorillonite (OMMT) nanoparticle reinforced polyethersulfone (PES) and PTFE ternary composites were prepared by the cold molding and vacuum sintering technology. The effects of sodium montmorillonite (Na‐MMT) and OMMT on the microstructures, thermal stabilities and tribological properties of PTFE composites were comparatively studied. The results show that the thermal stability of the PES/PTFE composites is clearly improved by the incorporation of OMMT nanoparticles. Not only the friction coefficients but also the wear rates of OMMT/PES/PTFE composites are less than those of Na‐MMT/PES/PTFE composites under identical tribological tests. Of all these PTFE composites, the PES/PTFE composite containing 10.0 wt% OMMT nanoparticles exhibits the best friction and wear properties (μ = 0.14, k = 5.78 × 10−15 m3 N–1 m−1). This can be attributed to the existence of a polymer multicomponent layer consisting of PTFE, PES and OMMT on the composite surface as well as the formation of uniform PTFE transfer film on the worn surfaces of metal counterparts.
Gait Measures at Admission to Inpatient Rehabilitation after Ischemic Stroke Predict 3‐Month Quality of Life and Function
Authors: Lin Chen , Lee Jungwha , Hurt Christopher P. , Lazar Ronald M. , Arevalo Yurany A. , Prabhakaran Shyam , Harvey Richard L.
Published: May 2020

Background

Ischemic stroke can impact a patient's quality of life, but the extent is unknown.

Objective

To evaluate the association between gait measures during inpatient rehabilitation with quality‐of‐life scores and function at 3 months in patients with stroke.

Setting

Single‐Center inpatient rehabilitation facility.

Participants

Eight five patients with ischemic stroke.

Methods

A 6‐Minute Walk Test and a 10‐Meter Walk Test were recorded on admission to rehabilitation. We analyzed the association between gait function at rehabilitation and 3‐month quality of life and poor functional outcome (modified Rankin Scale score >2) using multivariable logistic regression.

Main Outcome

Measures 3‐month health related quality of life.

Results

Eighty‐five patients (mean age 68.3 14.9 years; 54.3% male) were enrolled. In adjusted analyses, an increase of 0.31 m/s (ie, 1 SD) on the 10‐meter walk test was linked with a decreased odds of impaired lower extremity quality of life by 94% (odds ratio [OR] 0.06, 95% confidence interval [CI] 0.01–0.52; P =.01), and decreased odds of poor functional outcome by 98% (OR 0.02, 95% CI <0.01‐0.47; P =.01). For the 6‐minute walk test, an increase of 109.5 meters (ie, 1 SD) was linked with decreased odds of having impaired lower extremity quality of life by 1% (OR 0.99, 95% CI 0.98–1.00; P < .01) and poor functional outcome by 1% (OR 0.99, 95% CI 0.99–1.00; P = .04).

Conclusion

Gait measurements at rehabilitation can predict 3‐month lower extremity quality of life and function
Off‐Shell Amplitudes in String Theory and Hyperbolic Geometry
Authors: Moosavian Seyed Faroogh , Pius Roji
Published: May 2020

The construction of off‐shell amplitudes in closed string theory using Riemann surfaces having constant curvature −1 is explored in detail. Off‐shell string amplitudes constructed using surfaces with constant curvature −1 fail to satisfy the off‐shell factorization properties, and as a result, scattering amplitudes computed using them are ill‐defined. In this paper, we describe a procedure for systematically modifying this construction and obtain consistent off‐shell amplitudes in closed string theory satisfying the off‐shell factorization properties.
Double infection of Wolbachia and Spiroplasma alters induced plant defense and spider mite fecundity
Authors: Zhu Yu‐Xi , Song Zhang‐Rong , Song Yue‐Ling , Hong Xiao‐Yue
Published: May 2020

BACKGROUND

Herbivore‐associated bacterial symbionts can change plant physiology and influence herbivore fitness. The spider mite Tetranychus truncatus is a notorious pest harboring various bacterial symbionts; however, the effect of bacterial symbionts on host plant physiology remains unclear. Here, we investigated whether infection with the endosymbionts Wolbachia and Spiroplasma altered spider mite performance on tomato plants and affected plant‐induced defenses.

RESULTS

Wolbachia and Spiroplasma were mainly located in the gnathosoma and ovaries of their spider mite hosts. Wolbachia and Spiroplasma significantly improved spider mite reproductive performance in cultivated and wild‐type tomato. However, in plants deficient in jasmonic acid (JA) and salicylic acid (SA), there were no significant differences in reproduction between spider mites infected with Wolbachia and Spiroplasma and uninfected mites. The results indicated that the reproduction benefits conferred by endosymbionts may relate to plant defenses. Both spider mites infected with Wolbachia and Spiroplasma and uninfected mites induced similar levels of JA and SA accumulation in tomato, whereas tomato plants damaged by spider mites infected with both Wolbachia and Spiroplasma showed lower expression levels of JA‐ and SA‐responsive genes than those damaged by uninfected spider mites. In addition, mites infected with Wolbachia and Spiroplasma mites consumed more tomato amino acids compared to uninfected spider mites, which may have contributed to host fecundity.

CONCLUSIONS

Our results suggest that the reproduction benefits conferred by endosymbionts may be associated with changes in plant defense parameters and the concentrations of plant amino acids. The results highlight the importance of endosymbionts in interactions between spider mites and their host plants. © 2020 Society of Chemical Industry
Response times of meteorological air temperature sensors
Authors: Burt Stephen , de Podesta Michael
Published: May 2020

Guidelines in the Guide to Meteorological Instruments and Methods of Observation (the CIMO guide) of the World Meteorological Organization (WMO, published 2014, updated 2017, section 2.1.3.3, Response times of thermometers) recommend that the 63% response time τ for an air temperature sensor be 20 s, although – as airflow speed influences response time – the minimum airflow speed at which this applies should also be specified in the document. A 63% response time τ63 = 20 s implies that 95% of a step change be registered within 3τ63 or 60 s, the WMO recommended averaging interval for air temperature: rapid air temperature changes on this time‐scale are not uncommon, often associated with convective squalls, frontal systems or sea breeze circulations. An alternative way of expressing the effect of the time constant is that in air whose temperature is changing at 0.1 K·min−1 the thermometer would lag by approximately 0.03 K.

To assess whether this response time specification was realistic, we have undertaken an experimental and theoretical study of the time constants of meteorological thermometers. Laboratory wind tunnel tests were undertaken to quantify 63% and 95% response times of 25 commercial 100 Ω platinum resistance thermometers (PRTs) of various sizes (length and sheath diameter) from five manufacturers. The test results revealed a fourfold difference in response times between different sensors: none of the PRTs tested met the CIMO response time guideline at a ventilation speed of 1 m·s−1 assumed typical of passively ventilated thermometer shields such as Stevenson‐type thermometer screens. A theoretical model of the sensors was devised which matched the experimental behaviour with regard to the most important contributing factors, namely ventilation rate and sensor diameter. Finally, suggestions and recommendations for operational air temperature sensor adoption and future sensor development are included.
A recent review and a taxonomy for hard and soft tissue visualization‐based mixed reality
Authors: Tuladhar Selina , AlSallami Nada , Alsadoon Abeer , Prasad P.W.C. , Alsadoon Omar H. , Haddad Sami , Alrubaie Ahmad
Published: May 2020

Background

Mixed reality (MR) visualization is gaining popularity in image‐guided surgery (IGS) systems, especially for hard and soft tissue surgeries. However, a few MR systems are implemented in real time. Some factors are limiting MR technology and creating a difficulty in setting up and evaluating the MR system in real environments. Some of these factors include: the end users are not considered, the limitations in the operating room, and the medical images are not fully unified into the operating interventions.

Methodology

The purpose of this article is to use Data, Visualization processing, and View (DVV) taxonomy to evaluate the current MR systems. DVV includes all the components required to be considered and validated for the MR used in hard and soft tissue surgeries. This taxonomy helps the developers and end users like researchers and surgeons to enhance MR system for the surgical field.

Results

We evaluated, validated, and verified the taxonomy based on system comparison, completeness, and acceptance criteria. Around 24 state‐of‐the‐art solutions that are picked relate to MR visualization, which is then used to demonstrate and validate this taxonomy. The results showed that most of the findings are evaluated and others are validated.

Conclusion

The DVV taxonomy acts as a great resource for MR visualization in IGS. State‐of‐the‐art solutions are classified, evaluated, validated, and verified to elaborate the process of MR visualization during surgery. The DVV taxonomy provides the benefits to the end users and future improvements in MR.
A marsupial robotic system for surveying and inspection of freshwater ecosystems
Authors: Kalaitzakis Michail , Cain Brennan , Vitzilaios Nikolaos , Rekleitis Ioannis , Moulton Jason
Published: May 2020

Freshwater ecosystems are vast areas that are constantly changing and evolving. To maintain the ecosystem as well as the structures located close to bodies of water, frequent monitoring is required. Although dangerous and time consuming, manual operations are the conventional way of monitoring such areas. Recently, Autonomous Surface Vehicles (ASVs) have been proposed to undertake the monitoring task. As any other platform, ASVs have limitations, such as a restricted point of view and access only where the water is sufficiently deep. Unmanned Aerial Vehicles (UAVs) can fly over any terrain and provide a “bird's‐eye‐view” of the environment. However, UAVs have limited operational time due to power constraints. Heterogeneous marsupial robotic systems use different types of robots to augment their operation envelope, taking advantage of their individual strengths. A marsupial survey system comprised an ASV and a UAV for freshwater monitoring is developed and presented in this paper. This system is able to complete long missions and reach remote locations while also being able to generate detailed maps and inspections of points of interest. The system was thoroughly tested during a 6‐month period in a number of field deployments in freshwater ecosystems at Lake Murray and at the Congaree River, SC, USA, to validate its capabilities.
Quantifying the bias due to observed individual confounders in causal treatment effect estimates
Authors: Parast Layla , Griffin Beth Ann
Published: May 2020

It is often of interest to use observational data to estimate the causal effect of a target exposure or treatment on an outcome. When estimating the treatment effect, it is essential to appropriately adjust for selection bias due to observed confounders using, for example, propensity score weighting. Selection bias due to confounders occurs when individuals who are treated are substantially different from those who are untreated with respect to covariates that are also associated with the outcome. A comparison of the unadjusted, naive treatment effect estimate with the propensity score adjusted treatment effect estimate provides an estimate of the selection bias due to these observed confounders. In this article, we propose methods to identify the observed covariate that explains the largest proportion of the estimated selection bias. Identification of the most influential observed covariate or covariates is important in resource‐sensitive settings where the number of covariates obtained from individuals needs to be minimized due to cost and/or patient burden and in settings where this covariate can provide actionable information to healthcare agencies, providers, and stakeholders. We propose straightforward parametric and nonparametric procedures to examine the role of observed covariates and quantify the proportion of the observed selection bias explained by each covariate. We demonstrate good finite sample performance of our proposed estimates using a simulation study and use our procedures to identify the most influential covariates that explain the observed selection bias in estimating the causal effect of alcohol use on progression of Huntington's disease, a rare neurological disease.
Restorative and community‐building practices as social justice for English learners
Authors: Pentón Herrera Luis Javier , McNair Robin L.
Published: May 2020

In this theory‐based practice article, the authors introduce restorative and community‐building practices as social justice for English learners. As circle keepers and educators of English learners, the authors emphasize the necessity for reimagining English for speakers of other languages classrooms as not only places of learning English, but places of meditation, reflection, and healing for our students and ourselves. The article is divided into four main sections. In the first section, the authors define restorative and community‐building practices. In the second section, they investigate how and why restorative practices involve social justice. In the third section, they reflect on their work as restorative practices educators by sharing insights on some things teachers should consider when hoping to adopt restorative practices in their classes. In the fourth section, they share a sample of a restorative and community‐building circle educators can use with their English learners.
Second‐ and third‐trimester serum levels of growth‐differentiation factor‐15 in prediction of pre‐eclampsia
Authors: Wertaschnigg D. , Rolnik D. L. , Nie G. , Teoh S. S. Y. , Syngelaki A. , da Silva Costa F. , Nicolaides K. H.
Published: May 2020

Objective

Pre‐eclampsia (PE) is a significant contributor to adverse maternal and perinatal outcome; however, accurate prediction and early diagnosis of this condition remain a challenge. The aim of this study was to compare serum levels of growth‐differentiation factor‐15 (GDF‐15) at three different gestational ages between asymptomatic women who subsequently developed preterm or term PE and healthy controls.

Methods

This was a case–control study drawn from a prospective observational study on adverse pregnancy outcomes in women attending for their routine second‐ and third‐trimester hospital visits. Serum GDF‐15 was determined in 300 samples using a commercial GDF‐15 enzyme‐linked immunosorbent assay: 120 samples at 19–24 weeks of gestation, 120 samples at 30–34 weeks and 60 samples at 35–37 weeks. Multiple linear regression was applied to logarithmically transformed GDF‐15 control values to evaluate the influence of gestational age at blood sampling and maternal characteristics on GDF‐15 results. GDF‐15 multiples of the normal median (MoM) values, adjusted for gestational age and maternal characteristics, were compared between pregnancies that subsequently developed preterm or term PE and healthy controls.

Results

Values of GDF‐15 increased with gestational age. There were no significant differences in GDF‐15 MoM values between cases of preterm or term PE and normotensive pregnancies at 19–24 or 35–37 weeks of gestation. At 30–34 weeks, GDF‐15 MoM values were significantly increased in cases of preterm PE, but not in those who later developed term PE. Elevated GDF‐15 MoM values were associated significantly with a shorter interval between sampling at 30–34 weeks and delivery with PE (P = 0.005).

Conclusion

Serum GDF‐15 levels at 19–24 or 35–37 weeks of gestation are not predictive of preterm or term PE. At 30–34 weeks, GDF‐15 levels are higher in women who subsequently develop preterm PE; however, this difference is small and GDF‐15 is unlikely to be useful in clinical practice when used in isolation. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.
COngenital heart disease and the Diagnostic yield with Exome sequencing (CODE) study: prospective cohort study and systematic review
Authors: Mone F. , Eberhardt R. Y. , Morris R. K. , Hurles M. E. , McMullan D. J. , Maher E. R. , Lord J. , Chitty L. S. , Giordano J. L. , Wapner R. J. , Kilby M. D. ,   the CODE Study Collaborators
Published: May 2020

Objective

To determine the incremental yield of antenatal exome sequencing (ES) over chromosomal microarray analysis (CMA) or conventional karyotyping in prenatally diagnosed congenital heart disease (CHD).

Methods

A prospective cohort study of 197 trios undergoing ES following CMA or karyotyping owing to CHD identified prenatally and a systematic review of the literature were performed. MEDLINE, EMBASE, CINAHL and
ClinicalTrials.gov (January 2000 to October 2019) databases were searched electronically for studies reporting on the diagnostic yield of ES in prenatally diagnosed CHD. Selected studies included those with more than three cases, with initiation of testing based upon prenatal phenotype only and that included cases in which CMA or karyotyping was negative. The incremental diagnostic yield of ES was assessed in: (1) all cases of CHD; (2) isolated CHD; (3) CHD associated with extracardiac anomaly (ECA); and (4) CHD according to phenotypic subgroup.

Results

In our cohort, ES had an additional diagnostic yield in all CHD, isolated CHD and CHD associated with ECA of 12.7% (25/197), 11.5% (14/122) and 14.7% (11/75), respectively (P = 0.81). The corresponding pooled incremental yields from 18 studies (encompassing 636 CHD cases) included in the systematic review were 21% (95% CI, 15–27%), 11% (95% CI, 7–15%) and 37% (95% CI, 18–56%), respectively. The results did not differ significantly when subanalysis was limited to studies including more than 20 cases, except for CHD associated with ECA, in which the incremental yield was greater (49% (95% CI, 17–80%)). In cases of CHD associated with ECA in the primary analysis, the most common extracardiac anomalies associated with a pathogenic variant were those affecting the genitourinary system (23/52 (44.2%)). The greatest incremental yield was in cardiac shunt lesions (41% (95% CI, 19–63%)), followed by right‐sided lesions (26% (95% CI, 9–43%)). In the majority (68/96 (70.8%)) of instances, pathogenic variants occurred de novo and in autosomal dominant (monoallelic) disease genes. The most common (19/96 (19.8%)) monogenic syndrome identified was Kabuki syndrome.

Conclusions

There is an apparent incremental yield of prenatal ES in CHD. While the greatest yield is in CHD associated with ECA, consideration could also be given to performing ES in the presence of an isolated cardiac abnormality. A policy of routine application of ES would require the adoption of robust bioinformatic, clinical and ethical pathways. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.
Waves in nonlocal thermoelastic solids of type III
Authors: Sarkar Nihar , Bachher Mitali , Das Narayan , De Soumen , Sarkar Nantu
Published: May 2020

In this paper, the propagation of time‐harmonic thermoelastic plane waves is studied in an infinite nonlocal elastic continuum. The type III Green‐Naghdi model (with energy dissipation) of generalized thermoelasticity and the Eringen's nonlocal elasticity model are adopted to address this problem. We found two sets of the coupled longitudinal waves which are dispersive in nature and experience attenuation. In addition to the coupled waves, there also exists one independent vertically shear‐type wave which is dispersive but experiences no attenuation. All these waves are found to be influenced by the elastic nonlocality parameter. Furthermore, the shear‐type wave is found to face a critical frequency, while the coupled longitudinal waves may face critical frequencies conditionally. Reflection phenomenon of an incident coupled longitudinal waves from a rigid and thermally insulated boundary surface of a homogeneous and isotropic nonlocal thermoelastic half‐space is investigated. Using these boundary conditions, the formulae for various reflection coefficients and their respective energy ratios are presented. For a particular model, various graphs are plotted to analyze the behavior of the phase speeds, reflection coefficients and their respective energy ratios. The amplitude ratios of the reflected waves and their respective energy ratios are determined analytically. For a particular model, the effect of elastic nonlocality parameter on the variations of phase speeds, attenuation coefficients, amplitude ratios and corresponding energy ratios of the reflected waves are presented graphically. Finally, analysis of the various results have been interpreted.
Higher‐order perturbation solution of a free vibration problem of coupled piezoelectricity by Kato's theory
Authors: Cupiał Piotr
Published: May 2020

Kato's theory, which relies on the analytical properties of the resolvent of a differential operator, is used in this paper to obtain a closed‐form perturbation solution of an electromechanical free‐vibration problem of coupled piezoelectricity. Making use of the fact that piezoelectric coupling is not too strong, the natural frequencies and the mode shapes of the through‐thickness vibration of an infinite piezoelectric plate are calculated using a perturbation method. Explicit perturbation formulae have been derived up to the third‐order terms for the natural frequencies, whereas the closed‐form perturbation expressions for the mode shapes have been obtained up to the first‐order terms through the use of a projection operator. Numerical results are discussed for a plate with fixed‐free and free‐free faces. Since exact solutions exist for the problem in hand, the validity of the proposed method can be proved. The method differs from the perturbation approach usually used in quantum mechanics, since it does not rely on the expansion of the perturbation solution in series of the unperturbed eigenmodes; since the solutions are obtained in closed form, no issues of the convergence of infinite series arise. The perturbation approach used allows to obtain an approximate solution of a coupled problem by solving only the corresponding uncoupled elastic problem. The paper is a good illustration of the application of Kato's analytical method to solving a physical problem, which may be of interest for other vibration problems, too.
Geometric general solution to the U(1) anomaly equations
Authors: Allanach B C. , Gripaios Ben , Tooby-Smith Joseph
Published: May 2020

Abstract

Costa et al. [Phys. Rev. Lett.
123 (2019) 151601] recently gave a general solution to the anomaly equations for n charges in a U(1) gauge theory. ‘Primitive’ solutions of chiral fermion charges were parameterised and it was shown how operations performed upon them (concatenation with other primitive solutions and with vector-like solutions) yield the general solution. We show that the ingenious methods used there have a simple geometric interpretation, corresponding to elementary constructions in number theory. Viewing them in this context allows the fully general solution to be written down directly, without the need for further operations. Our geometric method also allows us to show that the only operation Costa et al. require is permutation. It also gives a variety of other, qualitatively similar, parameterisations of the general solution, as well as a qualitatively different (and arguably simpler) form of the general solution for n even.
Die Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit einem Signal-Rausch-Abstand (SNR) von 5 dB
Authors: Guy S. , Schönweiler R. , Wollenberg B. , Zehlicke T. , Pohl M. , Löhler J.
Published: May 2020

Hintergrund

Der Freiburger Einsilbertest (FBE) ist seit Langem einer der wesentlichen deutschen Sprachhörtests. Seit einiger Zeit wird er auch zur Messung der Hörverbesserung im Rahmen einer Hörgeräteversorgung im Störschall verwendet (FBE-S). Mit dieser Studie soll eine Verständlichkeitskurve für den Freiburger Einsilbertest im Störschall mit fixem Signal-Störschall-Verhältnis von 5 dB bei verschiedenen Schalldruckpegeln bestimmt werden.

Methode

Im Herbst 2018 wurden 60 normalhörende, muttersprachlich Deutsch sprechende Probanden im Alter zwischen 18 und 31 Jahren in der Klinik für HNO-Heilkunde des Bundeswehrkrankenhauses in Hamburg untersucht. Das Sprachverstehen wurde mit einer Testliste des FBE mit einem Schalldruckpegel von 15 bis 90 dB und einem 5 dB niedrigeren Störschall in 5‑dB-Schritten gemessen. Anschließend wurden von den Verständlichkeitsquoten die Mittelwerte gebildet und die 95%-Konfidenzintervalle (95%-KI) bestimmt.

Ergebnisse

Es nahmen 29 weibliche und 31 männliche Probanden an der Untersuchung teil. Das mittlere Alter aller Probanden betrug 24,32 Jahre (±3,39 Jahre). In der Varianzanalyse für fixe Effekte mit der Verständlichkeit als abhängiger Variablen zeigte sich ein hochsignifikanter Zusammenhang zwischen den Schalldruckpegeln des Sprach- und Störschalls auf der einen Seite und der Verständlichkeit auf der anderen Seite (p < 0,001). Die gemittelten Verständlichkeitsquoten und zugehörigen 95%-KI sowie die Häufigkeitsverteilungen wurden tabellarisch und grafisch dargestellt.

Schlussfolgerung

Die Verständlichkeitskurve des FBE‑S ist im Vergleich zur Normkurve des FBE nach rechts verschoben. Die gemittelte Kurve des FBE‑S erreicht bei einem Schalldruckpegel von 70 dB und einem Störschalldruckpegel von 65 dB den Sättigungsbereich von 90 % Verständlichkeit (zum Vergleich: Der Sättigungspunkt von 100 % Verständlichkeit liegt beim FBE ohne Störschall bei 55 dB). Durch die hier vorgestellte Verständlichkeitskurve lassen sich individuelle Messergebnisse ohne und mit Hörgeräten besser interpretieren. Künftig sollte der Hörgewinn für Hörgeräte möglicherweise bei niedrigeren Schalldruckpegeln erfolgen als heute.
Self-tuning robust adjustment within multivariate regression time series models with vector-autoregressive random errors
Authors: Kargoll Boris , Kermarrec Gaël , Korte Johannes , Alkhatib Hamza
Published: May 2020

The iteratively reweighted least-squares approach to self-tuning robust adjustment of parameters in linear regression models with autoregressive (AR) and t-distributed random errors, previously established in Kargoll et al. (in J Geod 92(3):271–297, 2018. 10.1007/s00190-017-1062-6), is extended to multivariate approaches. Multivariate models are used to describe the behavior of multiple observables measured contemporaneously. The proposed approaches allow for the modeling of both auto- and cross-correlations through a vector-autoregressive (VAR) process, where the components of the white-noise input vector are modeled at every time instance either as stochastically independent t-distributed (herein called “stochastic model A”) or as multivariate t-distributed random variables (herein called “stochastic model B”). Both stochastic models are complementary in the sense that the former allows for group-specific degrees of freedom (df) of the t-distributions (thus, sensor-component-specific tail or outlier characteristics) but not for correlations within each white-noise vector, whereas the latter allows for such correlations but not for different dfs. Within the observation equations, nonlinear (differentiable) regression models are generally allowed for. Two different generalized expectation maximization (GEM) algorithms are derived to estimate the regression model parameters jointly with the VAR coefficients, the variance components (in case of stochastic model A) or the cofactor matrix (for stochastic model B), and the df(s). To enable the validation of the fitted VAR model and the selection of the best model order, the multivariate portmanteau test and Akaike’s information criterion are applied. The performance of the algorithms and of the white noise test is evaluated by means of Monte Carlo simulations. Furthermore, the suitability of one of the proposed models and the corresponding GEM algorithm is investigated within a case study involving the multivariate modeling and adjustment of time-series data at four GPS stations in the EUREF Permanent Network (EPN).
Sharp Asymptotic Behavior of Solutions of the 3d Vlasov–Maxwell System with Small Data
Authors: Bigorgne Léo
Published: May 2020

We study the asymptotic properties of the small data solutions of the Vlasov–Maxwell system in dimension three. No neutral hypothesis nor compact support assumptions are made on the data. In particular, the initial decay in the velocity variable is optimal. We use vector field methods to obtain sharp pointwise decay estimates in null directions on the electromagnetic field and its derivatives. For the Vlasov field and its derivatives, we obtain, as in Fajman et al. (The Stability of the Minkowski space for the Einstein-Vlasov system, 2017. arXiv:1707.06141), optimal pointwise decay estimates by a vector field method where the commutators are modification of those of the free relativistic transport equation. In order to control high velocities and to deal with non integrable source terms, we make fundamental use of the null structure of the system and of several hierarchies in the commuted equations.
Baseline clinical characteristics and disease burden in patients with paroxysmal nocturnal hemoglobinuria (PNH): updated analysis from the International PNH Registry
Authors: Schrezenmeier Hubert , Röth Alexander , Araten David J. , Kanakura Yuzuru , Larratt Loree , Shammo Jamile M. , Wilson Amanda , Shayan Gilda , Maciejewski Jaroslaw P.
Published: May 2020

The International Paroxysmal Nocturnal Hemoglobinuria (PNH) Registry (NCT01374360) was initiated to optimize patient management by collecting data regarding disease burden, progression, and clinical outcomes. Herein, we report updated baseline demographics, clinical characteristics, disease burden data, and observed trends regarding clone size in the largest cohort of Registry patients. Patients with available data as of July 2017 were stratified by glycosylphosphatidylinositol (GPI)-deficient granulocyte clone size (< 10%, ≥ 10%–< 50%, and ≥ 50%). All patients were untreated with eculizumab at baseline, defined as date of eculizumab initiation or date of Registry enrollment (if never treated with eculizumab). Outcomes assessed in the current analysis included proportions of patients with high disease activity (HDA), history of major adverse vascular events (MAVEs; including thrombotic events [TEs]), bone marrow failure (BMF), red blood cell (RBC) transfusions, and PNH-related symptoms. A total of 4439 patients were included, of whom 2701 (60.8%) had available GPI-deficient granulocyte clone size data. Among these, median clone size was 31.8% (1002 had < 10%; 526 had ≥ 10%–< 50%; 1173 had ≥ 50%). There were high proportions of patients with HDA (51.6%), history of MAVEs (18.8%), BMF (62.6%), RBC transfusion (61.3%), and impaired renal function (42.8%). All measures except RBC transfusion history significantly correlated with GPI-deficient granulocyte clone size. A large proportion of patients with GPI-deficient granulocyte clone size < 10% had hemolysis (9.7%), MAVEs (10.2%), HDA (9.1%), and/or PNH-related symptoms. Although larger GPI-deficient granulocyte clone sizes were associated with higher disease burden, a substantial proportion of patients with smaller clone sizes had history of MAVEs/TEs.