bluuebunny/crossref_metadata_2025 huggingface dataset:
Sentidos e significados atribuídos por estudantes de Odontologia ao Estágio Rural em Saúde Coletiva
Authors: Pryjma Wendy Ramenã Alves da Silva , Pryjma Alexandre Augusto Leão , Neves André Luiz Machado das , Régis-Aranha Lauramaris De Arruda , Teixeira Elizabeth , Ferreira Breno De Oliveira
Published: December 2022

As atualizações das Diretrizes Curriculares Nacionais (DCN) estabelecidas para o curso de graduação em Odontologia destacaram que a formação do cirurgião-dentista deve se pautar nos princípios doutrinários do Sistema Único de Saúde (SUS), incluindo as proximidades com as necessidades de saúde de cada realidade loco-regional. Portanto, esta pesquisa teve como objetivo compreender os sentidos e os significados atribuídos à experiência do Estágio Rural em Saúde Coletiva (ERSC) por estudantes do curso de Odontologia de uma universidade pública localizada em Manaus, Amazonas. Trata-se de um estudo do tipo qualitativo com dezesseis estudantes matriculados na disciplina ERSC. A técnica de grupo focal foi utilizada na coleta de dados, que posteriormente foram analisados à luz da perspectiva histórico-cultural. Identificou-se três núcleos de significação: 1) “Ver como é o atendimento odontológico fora da Policlínica”: da bolha da Policlínica ao atendimento multiprofissional; 2) Maturidade e identidade profissional: “estarei lá como um dentista e não só como um estudante”; 3) Práxis do cirurgião-dentista: “aprender a trabalhar”. Os resultados mostraram que sentidos atribuídos à experiência são pendulares, tanto positivos como negativos, e conectam-se na relação trabalho, educação e saúde. Os estudantes consideraram que o ERSC era essencial para refletirem sobre a própria práxis, e identificarem quais pontos precisavam ser melhorados na formação acadêmica. O estágio foi, ainda, percebido como uma proposta que se alinhavava com as diversidades regionais e econômicas dos sistemas locais de saúde do SUS, levando em conta as peculiaridades e singularidades dos municípios do interior do Amazonas.
Programa Horta Educativa: reflexões sobre a experiência educativa em Limeira, SP
Authors: Zambelli Luana Cristina , Silva Natália Pereira , Oliveira Julicristie Machado de
Published: December 2022

Educar no campo da alimentação requer abordagens que incorporem sua complexidade e promova a compreensão das suas diversas dimensões. Nesse contexto, o presente estudo teve como objetivo analisar o Programa Horta Educativa, enquanto experiência nesse campo, considerando sua implementação no município de Limeira, SP. Foi realizado um estudo de caso embasado metodologicamente pela pesquisa documental e análise de conteúdo dos relatórios elaborados por seis escolas nos anos de 2016 e 2017, e por 23 escolas no ano de 2018, bem como pelas referências de Educação Ambiental e Educação Alimentar e Nutricional. A partir da análise, verifica-se que as atividades relatadas abordam a alimentação e o meio ambiente enquanto dimensão biológica, a partir de ações de transmissão de informações e a horta é considerada um instrumento de produção de alimentos. Sendo assim, infere-se que há o predomínio de uma abordagem reducionista e fragmentada de alimentação, a qual não compreende a complexidade e multidimensionalidade pertinentes. Portanto, os resultados obtidos suscitam que as atividades realizadas contradizem os princípios para ações de Educação Ambiental, Educação Alimentar e Nutricional e as perspectivas necessárias para abordar a alimentação e a nutrição.
Plataforma CHA para educadores: Perfil de uma amostra de docentes da educação básica frente às mudanças sociais e educativas decorrentes da pandemia do COVID-19
Authors: Mello-Silva Clélia Christina , Belo Mariana Soares da Silva Peixoto , Patricio Iza , Oliveira Rayne Helen , Bauer Vinicius , Camacho Marcelo
Published: December 2022

A Plataforma virtual CHA para educadores é uma tecnologia social de apoio aos educadores na ampliação de Conhecimentos e desenvolvimento de Habilidades e Atitudes em saúde para o enfrentamento das mudanças sociais e educacionais devido a COVID-19. O presente artigo apresenta análises quali-quantitativas de uma amostra da população de educadores da educação básica do Brasil, consultados pelo projeto para validação do mesmo. O estudo piloto foi realizado por meio de um questionário eletrônico distribuído nas mídias sociais por um mês para professores ativos da educação básica. Desses, 83 responderam a todo questionário, 75% são mulheres com média de idade de 41,3 anos com mais de 15 anos de magistério; 59% pertencem ao grupo de risco e atuam no ensino público; 52,6% estavam em luto e 43% têm dificuldade com as mídias digitais. Educadores (85%) relataram estar estressados e com medo. A maioria indicou trabalhar mais de 12 horas/dia (75%), mas identificaram que a presença dos alunos nas aulas remotas foi baixa. A análise de conteúdo dos discursos escritos no questionário diagnóstico revelou duas categorias, Saúde do Docente e Ensino-aprendizagem e 14 subcategorias (07 para cada) relacionadas aos impactos da pandemia na saúde do educador influenciando diretamente a sua práxis e a qualidade do processo de ensino-aprendizagem. Os resultados demonstraram a necessidade de um espaço de cuidado com a saúde do professor e de qualificação e troca profissional entre eles para a melhoria do processo de ensino-aprendizagem em tempos de pandemia COVID-19
The Development of Teacher and Student’s Book Based on Realistic Mathematics Education in Statistics for A package Program
Authors: Bayu Eka Pasca Surya , Fauzan Ahmad , Armiati Armiati
Published: December 2022

Development research demands a improvement in the implementation of learning by developing products based on learning needs. The products of this development are teacher book and student book based on the realistic mathematic education (RME) approach for package A in statistics material. Validity testing in this study includes instrument validation, self-evaluation, expert validation, one-to-one evaluation. Aiken's V and Intraclass Correlation Coefficient (ICC) are used to determine the validity and reliability of the product. The result of research shows that the instruments and prototype are valid and feasible. Then, the ICC obtained moderate stability, it also categorize reliable. In terms of context and hypothetical learning trajectory (HLT) developed, the products should be revised to achieve meaningful learning.
Hate Speech and the Gender Perspective: A Problem from the Teaching of Social Sciences in School
Authors: Marolla-Gajardo Jesús , Zurita-Garrido Felipe , Pinochet-Pinochet Sixtina , Castro-Palacios Guillermo
Published: December 2022

This study explores a socially relevant problem related to teachers' conceptions of hate speech from a gender perspective present in the discourse of teaching history and social science educational practices. The methodology was used within the paradigm with a case study design, as a generalization was not intended. The sample consisted of 80 professors of history and social sciences. A quantitative questionnaire was used to determine the conceptions of the participants. The main findings include the constraints placed by programs and curricula on the presence of hate speech, student interventions in classes, and strategies implemented by participating teachers to position counter-narratives to hate in their practice. The conclusions include the importance teachers place on analyzing the prevalence of hate speech in their practice, both by students and the media, and its impact on teaching. In addition, the results offer some educational insights and perspectives for positioning hate speech as a transformative social justice perspective.
Effects of Project-Based Learning on Postgraduate Students' Research Proposal Writing Skills
Authors: Khalaf Mustafa Ali , Alshammari Abdulaziz
Published: December 2022

Research is considered a vital component for propelling progress and development. This study aims to investigate the effects of problem-based learning (PBL) in the teaching of research methodology and statistics courses on improving research writing skills and enhancing course achievement. It also projects an action plan model for the effective implementation of PBL in the instructional aspect. The study utilised a positivist research paradigm based on action research design using the technique of content analysis. Employing a universal rubric, 45 proposals of graduate programme students enrolled in the College of Education at Minia University in North Upper Egypt were subjected to content analysis to rate students’ skills in writing research proposals before and after the delivery of the course. The students volunteered to participate in the study after they were given a synopsis of the aims and procedures. Students’ achievement was assessed through a test consisting of 90 items, developed primarily for this purpose at the end of the second semester in the academic year 2018–2019. The post-content analysis revealed a significant improvement in scientific research skills, with a considerable difference between the pre- and post-achievement scores. It is imperative to consider the feasibility of using the PBL approach in teaching research methodology and statistics courses for graduate students. The study recommended the adoption of PBL in undergraduate programmes as well as in high school education.
A Systematic Review of Research on Problems and Challenges Faced by Principals During the COVID-19 Pandemic
Authors: Urakova Fatima K. , Sudakova Alexandra V. , Kochneva Lyubov V. , Grishnova Elena E. , Asafova Elena V. , Garnaya-Ivanova Inna A.
Published: December 2022

COVID-19 affected all education stakeholders and led to school closures at the beginning of the spread of the pandemic. During the pandemic, principals had to manage their schools and faced many problems during the closure. Although there are numerous studies on school principals' challenges and difficulties during the COVID-19 pandemic, no systematic review study analyzes research about the principals' challenges and problems in the current literature. The purpose of this study is to provide a systematic review of the challenges and problems of principals during the COVID-19 pandemic from 2020 to 2022. The researcher analyzed 395 articles indexed in the ERIC and SCOPUS databases between 2020-2022. The results were analyzed using content analysis. The research results showed that 26 articles were suitable according to the analysis criteria. The results revealed that, in general, researchers focused on understanding principals' experiences regarding their challenges and problems during the pandemic. The results also showed that most articles were published in 2021, and most studies were conducted in The United States of America and Turkey. The results also show that qualitative studies are higher than quantitative. In addition, we found that the biggest challenges are inadequate equipment and lack of access to the internet and online resources during the pandemic. At the same time, the most common problems were identified as the adaptation of online teaching and inadequate infrastructure. The results from this research contribute to the body of the existing literature through a systematic review of the challenges and problems of principals during a pandemic and identifying the research gaps revealed from the analyzed studies.
Lung Nodule and Pulmonary Fibrosis at First Evaluation in Smoker Undergoing a Smoking Cessation Program
Authors: Pezzuto Aldo , Tammaro Antonella , Salerno Gerardo , Borro Marina , Carico Elisabetta
Published: December 2022

Smoking is the most significant avoidable risk factor. Responsible for a wide range of diseases such as cardiovascular diseases and acute or chronic respiratory diseases.

It is frequently associated with interstitial pulmonary diseases and notably, it can be a cause of idiopathic pulmonary fibrosis.

In this report, lung nodules and idiopathic pulmonary fibrosis were presented in a heavy smoker.
Leg length discrepancy assessment in total hip arthroplasty: is a pelvic radiograph sufficient?
Authors: Hardwick-Morris Max , Wigmore Estelle , Twiggs Joshua , Miles Brad , Jones Christopher W. , Yates Piers J.
Published: December 2022

Aims

Leg length discrepancy (LLD) is a common pre- and postoperative issue in total hip arthroplasty (THA) patients. The conventional technique for measuring LLD has historically been on a non-weightbearing anteroposterior pelvic radiograph; however, this does not capture many potential sources of LLD. The aim of this study was to determine if long-limb EOS radiology can provide a more reproducible and holistic measurement of LLD.

Methods

In all, 93 patients who underwent a THA received a standardized preoperative EOS scan, anteroposterior (AP) radiograph, and clinical LLD assessment. Overall, 13 measurements were taken along both anatomical and functional axes and measured twice by an orthopaedic fellow and surgical planning engineer to calculate intraoperator reproducibility and correlations between measurements.

Results

Strong correlations were observed for all EOS measurements (rs > 0.9). The strongest correlation with AP radiograph (inter-teardrop line) was observed for functional-ASIS-to-floor (functional) (rs = 0.57), much weaker than the correlations between EOS measurements. ASIS-to-ankle measurements exhibited a high correlation to other linear measurements and the highest ICC (rs = 0.97). Using anterior superior iliac spine (ASIS)-to-ankle, 33% of patients had an absolute LLD of greater than 10 mm, which was statistically different from the inter-teardrop LLD measurement (p < 0.005).

Discussion

We found that the conventional measurement of LLD on AP pelvic radiograph does not correlate well with long leg measurements and may not provide a true appreciation of LLD. ASIS-to-ankle demonstrated improved detection of potential LLD than other EOS and radiograph measurements. Full length, functional imaging methods may become the new gold standard to measure LLD. Cite this article: Bone Jt Open 2022;3(12):960–968.
Bessel acoustic-beam acoustic lens for extending the depth of field of detection in optical-resolution photoacoustic microscopy
Authors: Zeng Jiahao , Chen Anqing , Li Zihao , Song Xianlin
Published: December 2022

As an important part of optical-resolution photoacoustic microscopy, the acoustic lens is responsible for efficient collection of photoacoustic signals. The spherical focused acoustic lens is commonly used in photoacoustic microscopy because of its efficient detection of the photoacoustic signal in the focus area. However, the narrow depth of field of the spherical focused acoustic lens limits the expansion of the depth of field of the photoacoustic microscopy. To solve this problem, a Bessel acoustic-beam acoustic lens is proposed. The Bessel acoustic-beam acoustic lens replaces the spherical concave surface with a conical concave surface to generate a Bessel acoustic beam with non-diffraction. Using the simulation model of Bessel acoustic-beam acoustic lens constructed by COMSOL Multiphysics, it is verified theoretically that the Bessel acoustic-beam acoustic lens can improve the depth of field of detection by

∼

2

times. The Bessel acoustic-beam acoustic lens can further promote the capability of high-speed and large volumetric imaging of optical-resolution photoacoustic microscopy and will be helpful in the acquisition of physiological and pathological processes.
In situ, back-focal-plane-based determination of the numerical apertures in optical microscopes
Authors: Krüger Jan , Bergmann Detlef , Köning Rainer , Bodermann Bernd , Manske Eberhard
Published: December 2022

In this contribution, we present a technique for in situ determination of the numerical apertures (NAs) of optical microscopes using calibrated diffraction gratings. Many commonly practiced procedures use an external setup to determine the objective and condenser NAs. However, these values may become modified in the used microscope systems, e.g., by system intrinsic apertures. Therefore, in our improved technique, determination of the imaging NA is conducted in situ within the corresponding microscope at hand. Furthermore, the method has been extended to yield the microscope’s illumination NA as well. In total, we tested this procedure for determination of the imaging NA for four different microscope objectives with nominal values of 0.55 and 0.9, together with the illumination NAs for four different circular aperture diaphragms with diameters between 10 µm and 500 µm using several gratings of different pitches. All determined NA values agree essentially with their nominal values within their experimental uncertainties, but the uncertainties have been reduced by typically an order of magnitude as compared with the manufacturer’s specifications.
Error correction for Mueller matrix ellipsometry based on a reference optical path
Authors: Qi Jiao , Xue Peng , Zhang Rui , An Yongquan , Wang Zhibin , Li Mengwei
Published: December 2022

To reduce the error induced by light source fluctuations, motor rotation instability, environment, and other factors in real-time measurements using dual-rotating compensator Mueller matrix ellipsometry (DRC-MME), an error-correction method based on a reference optical path is proposed. A modified Mueller matrix expression was derived theoretically by introducing the reference optical path of the DRC-MME system. Simulation analysis and experimental verification of the air, polarizer, and

S
i

O

2

samples were performed using this method. The absolute error of the Mueller matrix elements of the

S
i

O

2

samples decreased from less than 0.028 to less than 0.008, and the standard deviation decreased from 0.9% to 0.3%. This method has certain guiding significance in improving the measurement accuracy of DRC-MME.
Increasing steering angle of LCoS in a WSS system through integration with a metasurface
Authors: Chang Xin , Pivnenko Mike , Shrestha Pawan , Wu Weijie , Chu Daping
Published: December 2022

Liquid crystal on silicon (LCoS) has been the dominant choice for wavelength selective switches (WSSs) in telecommunication industry due to its high spatial resolution and compatibility with software defined flexible grid feature. Current LCoS devices generally have a limited steering angle, which also limits the minimum footprint of the WSS system. The steering angle of LCoS devices is fundamentally determined by the pixel pitch, which is highly challenging to be optimized without resorting to other techniques. In this paper, we present an approach to increase the steering angle of LCoS devices through the integration with dielectric metasurfaces. Here a dielectric Huygens-type metasurface is integrated with an LCoS device to increase its steering angle by 10°. This approach can effectively minimize the overall size of the WSS system while maintaining a small form factor of the LCoS device.
Hough transform-based multi-object autofocusing compressive holography
Authors: Zhang Yiyi , Huang Zhengzhong , Jin Shangzhong , Cao Liangcai
Published: December 2022

Reconstruction of multiple objects from one hologram can be affected by the focus metric judgment of autofocusing. Various segmentation algorithms are applied to obtain a single object in the hologram. Each object is unambiguously reconstructed to acquire its focal position, which produces complicated calculations. Herein, Hough transform (HT)-based multi-object autofocusing compressive holography is presented. The sharpness of each reconstructed image is computed by using a focus metric such as entropy or variance. According to the characteristics of the object, the standard HT is further used for calibration to remove redundant extreme points. The compressive holographic imaging framework with a filter layer can eliminate the inherent noise in in-line reconstruction including cross talk noise of different depth layers, two-order noise, and twin image noise. The proposed method can effectively obtain 3D information on multiple objects and achieve noise elimination by only reconstructing from one hologram.
Ultrafast and low-power multichannel all-optical switcher based on multilayer graphene
Authors: Wang Guan , Wu Tong , Shao Yabin , Jia Yang , Gao Yang , Gao Yachen
Published: December 2022

A metal–insulator–metal waveguide structure composed of a hexagonal resonator cavity and a ring with a slit is proposed. By using the finite difference time domain method, the transmission properties of the structure were studied. It was found that three distinct plasmon-induced transparency peaks appear in the visible and near-infrared bands, and the transmissivity of the three peaks is more than 80%. By tuning the structure size, the positions of the peaks can be adjusted. Then we introduced graphene, covering the surface of the cavity. By adjusting the refraction index of the graphene using light, the position of the three transmission peaks can be changed correspondingly. Based on the effect, we designed an all-optical switcher with ultrafast optical response time (about 2 ps) and low light absorption (about 2.3%). The proposed waveguide structure provides a way for the development of visible and near-infrared filters and all-optical switchers.
Brillouin gain spectrum characterization in an acoustic anti-guided delivery fiber for high power narrow linewidth laser
Authors: He Dongyu , Liao Meisong , Hu Lili , Yu Chunlei , Qi Yunfeng , Shen Hui , Chen Liang , Yang Qiubai , Liu Meizhong , Wang Meng , Zhou Qinling , Gao Weiqing , Wang Tianxing
Published: December 2022

The Brillouin gain spectrum (BGS) provides key information for stimulated Brillouin scattering (SBS), such as the Brillouin frequency shift (BFS), Brillouin spontaneous linewidth, and Brillouin gain coefficient. In this study, we theoretically investigate the field distributions and BGS characterization of Ge-doped, Al-doped, and Al/Ge co-doped fibers. Additionally, we analyzed and compared the relationship between the BGS and acoustic refractive index. In particular, we demonstrate the crucial role played by acoustic modes in anti-waveguide structures. The simulation results show that the Brillouin gain coefficient decreases with a decreasing acoustic index in the fiber core region. Furthermore, we experimentally measure the SBS threshold and BGS of the Al/Ge co-doped fiber to examine the validity of the numerical model. The simulated and experimental results are consistent.
Large-area periodically-poled lithium niobate wafer stacks optimized for high-energy narrowband terahertz generation
Authors: Mosley Connor D. W. , Lake Daniel S. , Graham Darren M. , Jamison Steven P. , Appleby Robert B. , Burt Graeme , Hibberd Morgan T.
Published: December 2022

Periodically-poled lithium niobate (PPLN) sources consisting of custom-built stacks of large-area wafers provide a unique opportunity to systematically study the multi-cycle terahertz (THz) generation mechanism as they are assembled layer-by-layer. Here we investigate and optimize the THz emission from PPLN wafer stacks as a function of wafer number, pump fluence, pulse duration and chirp, wafer separation, and pump focusing. Using 135 µm-thick, 2"-diameter wafers we generate high-energy, narrowband THz pulses with central frequencies up to 0.39 THz, directly suitable for THz-driven particle acceleration applications. We explore the multi-cycle pulse build-up with increasing wafer numbers using electro-optic sampling measurements, achieving THz conversion efficiencies up to 0.17%, while demonstrating unique control over the pulse length and bandwidth these sources offer. Guided by simulations, observed frequency-dependence on both stack-mounting and pump focusing conditions have been attributed to inter-wafer etalon and Gouy phase-shifts respectively, revealing subtle features that are critical to the understanding and performance of PPLN wafer-stack sources for optimal narrowband THz generation.
Spatially resolved measurement of the distribution of solid and liquid Si nanoparticles in plasma synthesis through line-of-sight extinction spectroscopy
Authors: Liu Guannan , Wollny Patrick , Menser Jan , Dreier Thomas , Endres Torsten , Wlokas Irenaeus , Daun Kyle J. , Schulz Christof
Published: December 2022

In many high-temperature gas-phase nanoparticle synthesis processes, freshly nucleated particles are liquid and solidify during growth and cooling. This study presents an approach to determine the location of the liquid-to-solid phase transition and the volume fraction and number density of particles of both phases within a gas phase reactor. Spectrally-resolved line-of-sight attenuation (LOSA) measurements are applied to a silicon nanoparticle aerosol generated from monosilane in a microwave plasma reactor. A phantom-based analysis using particle number density, particle size, and temperature distribution from direct numerical simulation (DNS) of the reacting flow indicates that the contributions from the two particle phases can be decoupled under practical conditions, even with noisy data. The approach was applied to analyze spatially and spectrally resolved LOSA measurements from the hot gas flow downstream of the plasma zone where both solid and liquid silicon particles coexist. Extinction spectra were recorded along a line perpendicular to the flow direction by a spectrometer with an electron-multiplying charge-coupled device (EMCCD) camera, and two-dimensional projections were deconvolved to obtain radial extinction coefficient distributions of solid and liquid particles across the cross-section of the flow. Particle number densities of both particle phases were retrieved simultaneously based on the size-dependent extinction cross-sections of the nanoparticles. The particle-size distribution was determined via thermophoretic sampling at the same location with subsequent transmission electron microscopy (TEM) analysis. The particle temperature distribution was determined from the particle’s thermal radiation based on line-of-sight emission (LOSE) measurements. The approach for phase-selective data analysis can be transferred to other materials aerosol systems as long as significant differences exist in extinction spectra for the related different particle classes.
Broadband polarization splitter-rotator on a thin-film lithium niobate with conversion-enhanced adiabatic tapers
Authors: Shen Yuan , Ruan Ziliang , Chen Kaixuan , Liu Liu , Chen Bigeng , Rao Yunjiang
Published: December 2022

In this work, we propose and experimentally demonstrate a broadband polarization splitter-rotator (PSR) on the lithium niobate on insulator (LNOI). With multiple sequentially connected adiabatic tapers for waveguide mode conversion and directional coupling, the PSR shows a 160-nm bandwidth covering the C and L bands, an insertion loss of less than 2 dB, and an extinction ratio of more than 11 dB. Benefiting from the conversion-enhanced adiabatic tapers, the broadband device has a short length of 405 µm. Further optimization is performed to reduce the device length to 271 µm and comparable performances are achieved, demonstrating the feasibility of higher device compactness. The proposed design and principle can contribute to high-performance polarization management for integrated lithium niobate photonics.
Nonlinearity measurement undergoing dispersion and loss
Authors: Castelló-Lurbe David , Cuadrado-Laborde Christian , Silvestre Enrique , Díez Antonio , Andrés Miguel V.
Published: December 2022

Accurate knowledge of the nonlinear coefficient is extremely important to make reliable predictions about optical pulses propagating along waveguides. Nevertheless, determining this parameter when dispersion and loss are as important as nonlinear effects brings both theoretical and experimental challenges that have not yet been solved. A general method for measuring the nonlinear coefficient of waveguides under these demanding conditions is here derived and demonstrated experimentally in a kilometer-long standard silica fiber pumped close to 2 µm.
Rosetta FlexPepDock to predict peptide-MHC binding: An approach for non-canonical amino acids
Authors: Bloodworth Nathaniel , Barbaro Natália Ruggeri , Moretti Rocco , Harrison David G. , Meiler Jens
Published: December 2022

Computation methods that predict the binding of peptides to MHC-I are important tools for screening and identifying immunogenic antigens and have the potential to accelerate vaccine and drug development. However, most available tools are sequence-based and optimized only for peptides containing the twenty canonical amino acids. This omits a large number of peptides containing non-canonical amino acids (NCAA), or residues that undergo varied post-translational modifications such as glycosylation or phosphorylation. These modifications fundamentally alter peptide immunogenicity. Similarly, existing structure-based methods are biased towards canonical peptide backbone structures, which may or may not be preserved when NCAAs are present. Rosetta FlexPepDock ab-initio is a structure-based computational protocol able to evaluate peptide-receptor interaction where no prior information of the peptide backbone is known. We benchmarked FlexPepDock ab-initio for docking canonical peptides to MHC-I, and illustrate for the first time the method’s ability to accurately model MHC-I bound epitopes containing NCAAs. FlexPepDock ab-initio protocol was able to recapitulate near-native structures (≤1.5Å) in the top lowest-energy models for 20 out of 25 cases in our initial benchmark. Using known experimental binding affinities of twenty peptides derived from an influenza-derived peptide, we showed that FlexPepDock protocol is able to predict relative binding affinity as Rosetta energies correlate well with experimental values (r = 0.59, p = 0.006). ROC analysis revealed 80% true positive and a 40% false positive rate, with a prediction power of 93%. Finally, we demonstrate the protocol’s ability to accurately recapitulate HLA-A*02:01 bound phosphopeptide backbone structures and relative binding affinity changes, the theoretical structure of the lymphocytic choriomeningitis derived glycosylated peptide GP392 bound to MHC-I H-2Db, and isolevuglandin-adducted peptides. The ability to use non-canonical amino acids in the Rosetta FlexPepDock protocol may provide useful insight into critical amino acid positions where the post-translational modification modulates immunologic responses.
Prevalence of stillbirth and associated factors among deliveries attended in health facilities in Southern Ethiopia
Authors: Wolde Jegnaw , Haile Dereje , Paulos Kebreab , Alemayehu Mihiretu , Adeko Asrat Chernet , Ayza Asaminew
Published: December 2022

Background

Stillbirth is an unfavorable outcome of pregnancy, which is still prevalent in many countries despite remarkable efforts made to improve the care of pregnant women. While producing estimates consistent with other national reports, all are hindered by limited data and important causes of death are likely to be missed. However; there is a scarcity of data on stillbirth in Ethiopia particularly in the Wolaita zone.

Objective

To assess the prevalence and associated factors of stillbirth among women giving birth at public hospitals in the Wolaita zone, southern Ethiopia.

Methods

A facility-based cross-sectional study was conducted in public hospitals in the Wolaita zone. A stratified sampling technique was used to select 737 women. A pre-tested interviewer-administered questionnaire was used for data collection. Data were entered using Epidata version 3.1 and analyzed using SPSS version 20. Bivariate and multiple logistic regression analysis were used and the crude and adjusted odds ratios at a 95% confidence interval with P-value <0.05 were considered to declare the result as statistically significant.

Result

This study reported an 8.7% [95% CI: 6.5–10.8] prevalence of stillbirth. Women who lived in rural areas, had pregnancy and labor complications, a high number of pregnancies, a prior history of stillbirth, and a complicated delivery were associated with stillbirth. When compared to urban residents, being a rural resident increased the risk of stillbirth by 2.57 fold [adjusted OR = 2.57, 95% CI: 1.23, 5.40]. When compared to their counterparts, women who experienced complications during pregnancy and labor increased 6.23 fold [AOR = 6.23, 95% CI: 2.67–14.58], having a previous history of stillbirth increased 6.89 fold [AOR = 6.89, 95% CI: 2.57–13.57], and the type of delivery increased 7.13 fold the risk of stillbirth [AOR = 7.13, 95% CI: 2.71–18.73].

Conclusion and recommendation

The prevalence of stillbirth among women who gave birth in public hospitals in the Wolaita zone was found to be high compared to national and regional figures. Therefore, the federal and regional governments should strengthen inter-sectoral collaboration with health facilities to promote the maternal and health care services utilization. The zonal health department and other concerned bodies should focus on the implementation of the strategies and policies that address and reduce the causes of stillbirth.
Structural basis for matriglycan synthesis by the LARGE1 dual glycosyltransferase
Authors: Katz Michael , Diskin Ron
Published: December 2022

LARGE1 is a bifunctional glycosyltransferase responsible for generating a long linear polysaccharide termed matriglycan that links the cytoskeleton and the extracellular matrix and is required for proper muscle function. This matriglycan polymer is made with an alternating pattern of xylose and glucuronic acid monomers. Mutations in the LARGE1 gene have been shown to cause life-threatening dystroglycanopathies through the inhibition of matriglycan synthesis. Despite its major role in muscle maintenance, the structure of the LARGE1 enzyme and how it assembles in the Golgi are unknown. Here we present the structure of LARGE1, obtained by a combination of X-ray crystallography and single-particle cryo-EM. We found that LARGE1 homo-dimerizes in a configuration that is dictated by its coiled-coil stem domain. The structure shows that this enzyme has two canonical GT-A folds within each of its catalytic domains. In the context of its dimeric structure, the two types of catalytic domains are brought into close proximity from opposing monomers to allow efficient shuttling of the substrates between the two domains. Together, with putative retention of matriglycan by electrostatic interactions, this dimeric organization offers a possible mechanism for the ability of LARGE1 to synthesize long matriglycan chains. The structural information further reveals the mechanisms in which disease-causing mutations disrupt the activity of LARGE1. Collectively, these data shed light on how matriglycan is synthesized alongside the functional significance of glycosyltransferase oligomerization.
Spatial distribution and insecticide resistance profile of Aedes aegypti and Aedes albopictus in Douala, the most important city of Cameroon
Authors: Yougang Aurelie P. , Keumeni Christophe R. , Wilson-Bahun Theodel A. , Tedjou Armel N. , Njiokou Flobert , Wondji Charles , Kamgang Basile
Published: December 2022

Prevention and control of Aedes-borne viral diseases such as dengue rely on vector control, including the use of insecticides and reduction of larval sources. However, this is threatened by the emergence of insecticide resistance. This study aimed to update the spatial distribution, the insecticide resistance profile of A. aegypti and A. albopictus and the potential resistant mechanisms implicated in the city of Douala. Immature stages of Aedes were collected in August 2020 in eight neighbourhoods in Douala and reared to adult stages. Adult bioassays, and piperonyl butoxide (PBO) synergist assays were carried out according to World Health Organization recommendations. Expression of some candidate metabolic genes including Cyp9M6F88/87, Cyp9J28a, Cyp9J10 and Cyp9J32 in A. aegypti, and Cyp6P12 in A. albopictus were assessed using qPCR. A. aegypti adults G0 were screened using real time melting curve qPCR analyses to genotype the F1534C, V1016I and V410L Aedes kdr mutations. Overall, A. aegypti is the predominant Aedes species, but analyses revealed that both A. albopictus and A. aegypti coexist in all the prospected neighbourhoods of Douala. High level of resistance was observed to three pyrethroids tested in both Aedes species. In A. aegypti a lower mortality rate was reported to permethrin (5.83%) and a higher mortality rate to deltamethrin (63.74%). Meanwhile, for A. albopictus, lower (6.72%) and higher (84.11%) mortality rates were reported to deltamethrin. Similar analysis with bendiocarb, revealed for A. aegypti a loss of susceptibility. However, in A. albopictus samples, analyses revealed a susceptibility in Logbessou, and confirmed resistance in Kotto (59.78%). A partial recovery of mortality was found to insecticides after pre-exposure to PBO. Cyp6P12 was found significantly overexpressed in A. albopictus permethrin resistant and Cyp9M6F88/87 for A. aegypti deltamethrin resistant. F1534C, V1016I and V410L mutations were detected in A. aegypti from different neighbourhoods and by considering the combination of these three kdr 14 genotypes were found. These findings provide relevant information which should be capitalised in the implementation of arbovirus vector control strategies and insecticide resistance management.
A GIS workflow for the identification of corridors of geomorphic river recovery across landscapes
Authors: Agnew Danelle , Graves Bradley P. , Fryirs Kirstie
Published: December 2022

The provision of a simplified GIS workflow to analyse the Open Access NSW River Styles database provides non-technical GIS users in river management with the ability to quickly and efficiently obtain information to assist them in catchment-scale rehabilitation prioritisation. Publicly available proprietary GIS software, standard GIS tools, and a packaged digital elevation model are used to demonstrate the ease of analysis for those with some GIS skills, to establish where corridors of geomorphic river recovery occur or could be built at-scale. Rather than a ‘single use’ report, this novel application of GIS methods is designed to be used by those responsible for river management, replicated across landscapes and adjusted according to preferences. Decision making becomes more cost effective, and adaptive to local circumstances and changing river management priorities. The method could also be adjusted and applied to other river monitoring and condition datasets where polyline data layers are available.
Multi-layer perceptron classification & quantification of neuronal survival in hypoxic-ischemic brain image slices using a novel gradient direction, grey level co-occurrence matrix image training
Authors: Bhattacharya Saheli , Bennet Laura , Davidson Joanne O. , Unsworth Charles P.
Published: December 2022

Hypoxic ischemic encephalopathy (HIE) is a major global cause of neonatal death and lifelong disability. Large animal translational studies of hypoxic ischemic brain injury, such as those conducted in fetal sheep, have and continue to play a key role in furthering our understanding of the cellular and molecular mechanisms of injury and developing new treatment strategies for clinical translation. At present, the quantification of neurons in histological images consists of slow, manually intensive morphological assessment, requiring many repeats by an expert, which can prove to be time-consuming and prone to human error. Hence, there is an urgent need to automate the neuron classification and quantification process. In this article, we present a ’Gradient Direction, Grey level Co-occurrence Matrix’ (GD-GLCM) image training method which outperforms and simplifies the standard training methodology using texture analysis to cell-classification. This is achieved by determining the Grey level Co-occurrence Matrix of the gradient direction of a cell image followed by direct passing to a classifier in the form of a Multilayer Perceptron (MLP). Hence, avoiding all texture feature computation steps. The proposed MLP is trained on both healthy and dying neurons that are manually identified by an expert and validated on unseen hypoxic-ischemic brain slice images from the fetal sheep in utero model. We compared the performance of our classifier using the gradient magnitude dataset as well as the gradient direction dataset. We also compare the performance of a perceptron, a 1-layer MLP, and a 2-layer MLP to each other. We demonstrate here a way of accurately identifying both healthy and dying cortical neurons obtained from brain slice images of the fetal sheep model under global hypoxia to high precision by identifying the most minimised MLP architecture, minimised input space (GLCM size) and minimised training data (GLCM representations) to achieve the highest performance over the standard methodology.
Homocysteine causes neuronal leptin resistance and endoplasmic reticulum stress
Authors: Preninka Arini Isnani , Kuriya Karen , Yazawa Kyosuke , Yoshii Michiko , Yanase Yuhki , Jockers Ralf , Dam Julie , Hosoi Toru , Ozawa Koichiro
Published: December 2022

Abnormally high serum homocysteine levels have been associated with several disorders, including obesity, cardiovascular diseases or neurological diseases. Leptin is an anti-obesity protein and its action is mainly mediated by the activation of its Ob-R receptor in neuronal cells. The inability of leptin to induce activation of its specific signaling pathways, especially under endoplasmic reticulum stress, leads to the leptin resistance observed in obesity. The present study examined the effect of homocysteine on leptin signaling in SH-SY5Y neuroblastoma cells expressing the leptin receptor Ob-Rb. Phosphorylation of the signal transducer and activator of transcription (STAT3) and leptin-induced STAT3 transcriptional activity were significantly inhibited by homocysteine treatment. These effects may be specific to homocysteine and to the leptin pathway, as other homocysteine-related compounds, namely methionine and cysteine, have weak effect on leptin-induced inhibition of STAT3 phosphorylation, and homocysteine has no impact on IL-6-induced activation of STAT3. The direct effect of homocysteine on leptin-induced Ob-R activation, analyzed by Ob-R BRET biosensor to monitor Ob-R oligomerization and conformational change, suggested that homocysteine treatment does not affect early events of leptin-induced Ob-R activation. Instead, we found that, unlike methionine or cysteine, homocysteine increases the expression of the endoplasmic reticulum (ER) stress response gene, a homocysteine-sensitive ER resident protein. These results suggest that homocysteine may induce neuronal resistance to leptin by suppressing STAT3 phosphorylation downstream of the leptin receptor via ER stress.
Association between cigarette smoking and ovarian reserve among women seeking fertility care
Authors: Oladipupo Islamiat , Ali T’shura , Hein David W. , Pagidas Kelly , Bohler Henry , Doll Mark A. , Mann Merry Lynn , Gentry Adrienne , Chiang Jasmine L. , Pierson Rebecca C. , Torres Sashia , Reece Emily , Taylor Kira C.
Published: December 2022

Introduction

This study examined the association of smoking with ovarian reserve in a cross-sectional study of 207 women enrolled in the Louisville Tobacco Smoke Exposure, Genetic Susceptibility, and Infertility (LOUSSI) Study and assessed effect modification by NAT2 acetylator phenotype.

Methods

Information on current smoking status was collected using a structured questionnaire and confirmed by cotinine assay. Serum anti-Müllerian hormone (AMH) levels were used to assess ovarian reserve. Diminished ovarian reserve (DOR) was defined as AMH <1ng/mL. Single nucleotide polymorphisms in the NAT2 gene, which metabolizes toxins found in cigarette smoke, were analyzed to determine NAT2 acetylator status. Linear and logistic regression were used to determine the effects of smoking on ovarian reserve and evaluate effect modification by NAT2. Regression analyses were stratified by polycystic ovary syndrome (PCOS) status and adjusted for age.

Results

Current smoking status, either passive or active as measured by urinary cotinine assay, was not significantly associated with DOR. For dose-response assessed using self-report, the odds of DOR increased significantly for every additional cigarette currently smoked (Odds ratio, OR:1.08; 95% confidence interval, 95%CI:1.01–1.15); additionally, every 1 pack-year increase in lifetime exposure was associated with an increased odds of DOR among women without PCOS (OR: 1.08 95%CI: 0.99–1.18). These trends appear to be driven by the heavy or long-term smokers. Effect modification by NAT2 genotype was not established.

Conclusion

A history of heavy smoking may indicate increased risk of diminished ovarian reserve.
Accuracy of the electronic health record’s problem list in describing multimorbidity in patients with heart failure in the emergency department
Authors: King Brandon L. , Meyer Michelle L. , Chari Srihari V. , Hurka-Richardson Karen , Bohrmann Thomas , Chang Patricia P. , Rodgers Jo Ellen , Busby-Whitehead Jan , Casey Martin F.
Published: December 2022

Patients with heart failure (HF) often suffer from multimorbidity. Rapid assessment of multimorbidity is important for minimizing the risk of harmful drug-disease and drug-drug interactions. We assessed the accuracy of using the electronic health record (EHR) problem list to identify comorbid conditions among patients with chronic HF in the emergency department (ED). A retrospective chart review study was performed on a random sample of 200 patients age ≥65 years with a diagnosis of HF presenting to an academic ED in 2019. We assessed participant chronic conditions using: (1) structured chart review (gold standard) and (2) an EHR-based algorithm using the problem list. Chronic conditions were classified into 37 disease domains using the Agency for Healthcare Research Quality’s Elixhauser Comorbidity Software. For each disease domain, we report the sensitivity, specificity, positive predictive value, and negative predictive of using an EHR-based algorithm. We calculated the intra-class correlation coefficient (ICC) to assess overall agreement on Elixhauser domain count between chart review and problem list. Patients with HF had a mean of 5.4 chronic conditions (SD 2.1) in the chart review and a mean of 4.1 chronic conditions (SD 2.1) in the EHR-based problem list. The five most prevalent domains were uncomplicated hypertension (90%), obesity (42%), chronic pulmonary disease (38%), deficiency anemias (33%), and diabetes with chronic complications (30.5%). The positive predictive value and negative predictive value of using the EHR-based problem list was greater than 90% for 24/37 and 32/37 disease domains, respectively. The EHR-based problem list correctly identified 3.7 domains per patient and misclassified 2.0 domains per patient. Overall, the ICC in comparing Elixhauser domain count was 0.77 (95% CI: 0.71-0.82). The EHR-based problem list captures multimorbidity with moderate-to-good accuracy in patient with HF in the ED.