bluuebunny/crossref_metadata_2025 huggingface dataset:
Freeform gradient index generalized Coddington’s equations
Authors: Kochan Nicholas S. , Schmidt Greg R. , Moore Duncan T.
Published: February 2022

Coddington’s equations and their generalized forms are useful for lens design and analysis of optical performance. Generalized Coddington’s equations (GCE) exist in literature for analysis of decentered systems and freeform surfaces, but not for gradient index (GRIN) lenses. In this work, GCE are presented for the analysis of freeform GRIN lenses with freeform surfaces. Examples are shown where the presented theory converges on Coddington’s equations and known paraxial GRIN behavior. The method also correctly shows known afocal behavior proximate to azimuthally directed rays in a cylindrical GRIN. The latter case is one of analytically validated local freeform behavior.
Unidirectional transmission of visible region topological edge states in hexagonal boron nitride valley photonic crystals
Authors: Wu Min , Yang Yibiao , Fei Hongming , Lin Han , Han Yuhui , Zhao Xiaodan , Chen Zhihui
Published: February 2022

Here we theoretically design valley photonic crystals (VPCs) based on two-dimensional (2D) hexagonal boron nitride (hBN) materials, which are able to support topological edge states in the visible region. The edge states can achieve spin-dependent unidirectional transmission with a high forward transmittance up to 0.96 and a transmission contrast of 0.99. We further study the effect of refractive index on transmittance and bandwidth, and it is found that with the increase of refractive index, both transmittance and bandwidth increased accordingly. This study opens new possibilities in designing unidirectional transmission devices in the visible region and will find broad applications.
Short bends using curved mirrors in silicon waveguides for terahertz waves
Authors: Verstuyft Mattias , Akiki Elias , Vanwolleghem Mathias , Ducournau Guillaume , Lampin Jean-François , Walter Benjamin , Bavedila Fuanki , Lebouvier Édouard , Faucher Marc , Kuyken Bart
Published: February 2022

Dielectric waveguides are capable of confining and guiding terahertz waves along sub-wavelength sized structures. A small feature size allows for a denser integration of different photonic components such as modulators, beam-splitters, wavelength (de)multiplexers and more. The integration of components on a small scale requires bending of the waveguides. In this paper we demonstrate a very short silicon 90°-bend, based on total internal reflection on an elliptically curved outer facet and a rounding of the inner corner joining two waveguides, with an average loss of 0.14 dB per bend in the 600-750 GHz range.
Compact fiber-free parallel-plane multi-wavelength diffuse optical tomography system for breast imaging
Authors: Wang Yihan , Li Songpeng , Wang Yirong , Yan Qiang , Wang Xin , Shen Yudong , Li Zhiqiang , Kang Fei , Cao Xu , Zhu Shouping
Published: February 2022

To facilitate the clinical applicability of the diffuse optical inspection device, a compact multi-wavelength diffuse optical tomography system for breast imaging (compact-DOTB) with a fiber-free parallel-plane structure was designed and fabricated for acquiring three-dimensional optical properties of the breast in continuous-wave mode. The source array consists of 56 surface-mounted micro light-emitting diodes (LEDs), each integrating three wavelengths (660, 750, and 840 nm). The detector array is arranged with 56 miniaturized surface-mounted optical sensors, each encapsulating a high-sensitivity photodiode (PD) and a low-noise current amplifier with a gain of 24×. The system provides 3,136 pairs of source-detector measurements at each wavelength, and the fiber-free design largely ensures consistency between source/detection channels while effectively reducing the complexity of system operation and maintenance. We have evaluated the compact-DOTB system’s characteristics and demonstrated its performance in terms of reconstruction positioning accuracy and recovery contrast with breast-sized phantom experiments. Furthermore, the breast cancer patient studies have been carried out, and the quantitative results indicate that the compact-DOTB system is able to observe the changes in the functional tissue components of the breast after receiving the neoadjuvant chemotherapy (NAC), demonstrating the great potential of the proposed compact system for clinical applications, while its cost and ease of operation are competitive with the existing breast-DOT devices.
Investigation of a Raman scattering spectral model for seawater containing a composite salt solute
Authors: Bao Dong , Hua Dengxin , Qi Hao , Wang Jun
Published: February 2022

To satisfy the demand for active remote sensing of ocean salinity, this paper proposes a Raman spectra, salinity, and temperature model for seawater. Seawater is a solution containing a composite salt solute, changes in the solute, temperature, and salinity of seawater can affect the intensity of Raman spectra. It is difficult to directly analyze the influence of various factors on the Raman spectra of seawater. Therefore, the Raman spectra of solutions containing a single solute and mixed solutions were detected, and the effect of solutions containing different solutes on the spectra was analyzed. The experimental results revealed the variation in the low- and high-frequency spectral intensities of the Raman spectra with salinity and temperature. The Raman spectra of seawater were modeled as a function of temperature and salinity using the low- and high-frequency area ratios, and the spectra of seawater at different salinities were obtained; the model calculation results are consistent with the experimental results within the entire range of seawater temperature and salinity. Because the Raman spectra were a function of temperature and salinity. To achieve high precision remote sensing of ocean salinity, it is necessary to use Brillouin scattering for remote sensing of ocean temperature.
Analysis and suppression of the misalignment error for the pumping laser in the atomic comagnetometer
Authors: Huang Jiong , Fan Wenfeng , Wang Zhuo , Yuan Linlin , Zhang Kai , Pei Hongyu , Pang Haoying , Quan Wei
Published: February 2022

The misalignment error of the pumping laser in the atomic comagnetometer (ACM) dramatically diminishes the efficiency of the optical pumping process (characterized by the polarization of the hybrid atomic spin ensembles containing electron spins and nuclear spins) and deteriorates the performance of the ACM (characterized by the Allan standard deviation). In this work, a steady-state response model considering the misalignment error of the pumping laser is established and an in-situ evaluation method for this error is proposed. Based on the evaluation method, the influence of this misalignment error on the pumping efficiency and the performance of the ACM is quantitatively analyzed. Furthermore, a pumping laser alignment method based on the second harmonic of a single-beam magnetometer is then proposed, whose effectiveness is verified by experiments. The experimental results show that compared to the original ACM with the severely misaligned pumping laser, the polarization of the hybrid atomic spin ensembles of the ACM with the pumping laser aligned by the proposed method is increased by about 19%, and the corresponding Allan variance at 100s is reduced by about 40%.
Optical nanotopography of fluorescent surfaces by axial position modulation
Authors: Kim Inhong , Leblanc Julien , Moreau Philippe , Kyhm Kwangseuk , Dupont Aurélie , Wang Irene
Published: February 2022

We present an optical method that combines confocal microscopy with position modulation to perform axial tracking and topographic imaging of fluorescent surfaces. Using a remote focusing system, the confocal observation volume is oscillated in the axial direction. The resulting modulation of the detected signal is used as a feedback to precisely control the distance to an object of interest. The accuracy of this method is theoretically analyzed and the axial-locking accuracy is experimentally evaluated. Topographic imaging is demonstrated on fluorescently coated beads and fixed cells. This microscope allows for nanometric topography or tracking of dynamic fluorescent surfaces.
Acoustic microresonator based in-plane quartz-enhanced photoacoustic spectroscopy sensor with a line interaction mode
Authors: Lang Ziting , Qiao Shunda , Ma Yufei
Published: February 2022

An acoustic microresonator (AmR) based in-plane quartz-enhanced photoacoustic spectroscopy (IP-QEPAS) sensor with a line interaction mode is proposed for what is believed to be the first time. The interaction area for the acoustic wave of the proposed AmR, with a slotted sidewall, is not limited to a point of the quartz tuning fork (QTF) prongs, but extends along the whole plane of the QTF prongs. Sixteen types of AmRs are designed to identify the best parameters. Water vapor (H2O) is chosen as the analyte to verify the reported method. The results indicate that this AmR for IP-QEPAS with a line interaction mode not only provides a high signal level, but also reduces the thermal noise caused by the laser directly illuminating the QTF. Compared with standard IP-QEPAS without an AmR, the minimum detection limit (MDL) is improved by 4.11 times with the use of the technique proposed in this study.
Effects of the polarization field on optical transitions and selection rules in Er doped GaN
Authors: Yan Yaqiong , Li Jing , Lin Jingyu , Jiang Hongxing
Published: February 2022

Effects of the polarization field on the Er3+ intra-4f shell transitions in GaN have been investigated via comparison of photoluminescence emission spectroscopy studies conducted on Er:GaN and Er:YAG. The dominant optical transitions were compared and analyzed. It was observed that the dominant optical transitions in Er:GaN/Er:YAG are between the Stark levels of the same/different irreducible representations. The unique selection rules in Er:GaN are a consequence of the presence of a net local polarization field acting on Er due to the wurtzite crystal structure of GaN. The results provide useful insights into understanding of the dominant optical transitions and the most probable emission lines to be utilized to achieve lasing in Er:GaN.
Simple synthetic route to Ca18.75Li10.5[Al39N55]:Ce3+ yellow-green phosphors for white LEDs
Authors: Hu Dahai , Wang Fengxiang , Li Xiang , Ma Yizhi , Zhang Yu , Wang Xinran , Liu Yongfu , Chao Kefu
Published: February 2022

Nitride phosphors usually have great influence on the performance of white LEDs. However, most nitrides require synthesis under high temperature and high pressure, especially Ca18.75Li10.5[Al39N55] (CLAN), which demands preparation even under a pressure of 51.7 MPa. Herein, we applied a simple synthetic route to obtain CLAN at a low pressure of 0.85 MPa and temperature of 1250 °C. In addition, the luminescence properties of Ce3+ doped CLAN were studied and the CLAN:Ce3+ shows three excitation bands peaked at 267, 387, and 478 nm. Two emission peaks are located at 513 nm and 567 nm, corresponding to the d-f electronic transition of Ce3+, respectively. The emission intensity at 150 °C retains about 83.3% of the initial value at room temperature, indicating a good thermal stability. A prototype white LED encapsulated with a 450 nm chip and the CLAN:Ce3+ phosphor exhibits bright white emission, indicating potential applications.
INTEGRATE: Model-based multi-omics data integration to characterize multi-level metabolic regulation
Authors: Di Filippo Marzia , Pescini Dario , Galuzzi Bruno Giovanni , Bonanomi Marcella , Gaglio Daniela , Mangano Eleonora , Consolandi Clarissa , Alberghina Lilia , Vanoni Marco , Damiani Chiara
Published: February 2022

Metabolism is directly and indirectly fine-tuned by a complex web of interacting regulatory mechanisms that fall into two major classes. On the one hand, the expression level of the catalyzing enzyme sets the maximal theoretical flux level (i.e., the net rate of the reaction) for each enzyme-controlled reaction. On the other hand, metabolic regulation controls the metabolic flux through the interactions of metabolites (substrates, cofactors, allosteric modulators) with the responsible enzyme. High-throughput data, such as metabolomics and transcriptomics data, if analyzed separately, do not accurately characterize the hierarchical regulation of metabolism outlined above. They must be integrated to disassemble the interdependence between different regulatory layers controlling metabolism. To this aim, we propose INTEGRATE, a computational pipeline that integrates metabolomics and transcriptomics data, using constraint-based stoichiometric metabolic models as a scaffold. We compute differential reaction expression from transcriptomics data and use constraint-based modeling to predict if the differential expression of metabolic enzymes directly originates differences in metabolic fluxes. In parallel, we use metabolomics to predict how differences in substrate availability translate into differences in metabolic fluxes. We discriminate fluxes regulated at the metabolic and/or gene expression level by intersecting these two output datasets. We demonstrate the pipeline using a set of immortalized normal and cancer breast cell lines. In a clinical setting, knowing the regulatory level at which a given metabolic reaction is controlled will be valuable to inform targeted, truly personalized therapies in cancer patients.
Quantifying cumulative phenotypic and genomic evidence for procedural generation of metabolic network reconstructions
Authors: Moutinho Thomas J. , Neubert Benjamin C. , Jenior Matthew L. , Papin Jason A.
Published: February 2022

Genome-scale metabolic network reconstructions (GENREs) are valuable tools for understanding microbial metabolism. The process of automatically generating GENREs includes identifying metabolic reactions supported by sufficient genomic evidence to generate a draft metabolic network. The draft GENRE is then gapfilled with additional reactions in order to recapitulate specific growth phenotypes as indicated with associated experimental data. Previous methods have implemented absolute mapping thresholds for the reactions automatically included in draft GENREs; however, there is growing evidence that integrating annotation evidence in a continuous form can improve model accuracy. There is a need for flexibility in the structure of GENREs to better account for uncertainty in biological data, unknown regulatory mechanisms, and context-specificity associated with data inputs. To address this issue, we present a novel method that provides a framework for quantifying combined genomic, biochemical, and phenotypic evidence for each biochemical reaction during automated GENRE construction. Our method, Constraint-based Analysis Yielding reaction Usage across metabolic Networks (CANYUNs), generates accurate GENREs with a quantitative metric for the cumulative evidence for each reaction included in the network. The structuring of CANYUNs allows for the simultaneous integration of three data inputs while maintaining all supporting evidence for biochemical reactions that may be active in an organism. CANYUNs is designed to maximize the utility of experimental and annotation datasets and to ultimately assist in the curation of the reference datasets used for the automatic construction of metabolic networks. We validated CANYUNs by generating an E. coli K-12 model and compared it to the manually curated reconstruction iML1515. Finally, we demonstrated the use of CANYUNs to build a model by generating an E. coli Nissle CANYUNs model using novel phenotypic data that we collected. This method may address key challenges for the procedural construction of metabolic networks by leveraging uncertainty and redundancy in biological data.
Evaluating supervised and unsupervised background noise correction in human gut microbiome data
Authors: Briscoe Leah , Balliu Brunilda , Sankararaman Sriram , Halperin Eran , Garud Nandita R.
Published: February 2022

The ability to predict human phenotypes and identify biomarkers of disease from metagenomic data is crucial for the development of therapeutics for microbiome-associated diseases. However, metagenomic data is commonly affected by technical variables unrelated to the phenotype of interest, such as sequencing protocol, which can make it difficult to predict phenotype and find biomarkers of disease. Supervised methods to correct for background noise, originally designed for gene expression and RNA-seq data, are commonly applied to microbiome data but may be limited because they cannot account for unmeasured sources of variation. Unsupervised approaches address this issue, but current methods are limited because they are ill-equipped to deal with the unique aspects of microbiome data, which is compositional, highly skewed, and sparse. We perform a comparative analysis of the ability of different denoising transformations in combination with supervised correction methods as well as an unsupervised principal component correction approach that is presently used in other domains but has not been applied to microbiome data to date. We find that the unsupervised principal component correction approach has comparable ability in reducing false discovery of biomarkers as the supervised approaches, with the added benefit of not needing to know the sources of variation apriori. However, in prediction tasks, it appears to only improve prediction when technical variables contribute to the majority of variance in the data. As new and larger metagenomic datasets become increasingly available, background noise correction will become essential for generating reproducible microbiome analyses.
Connectivity and dynamics in the olfactory bulb
Authors: Kersen David E. Chen , Tavoni Gaia , Balasubramanian Vijay
Published: February 2022

Dendrodendritic interactions between excitatory mitral cells and inhibitory granule cells in the olfactory bulb create a dense interaction network, reorganizing sensory representations of odors and, consequently, perception. Large-scale computational models are needed for revealing how the collective behavior of this network emerges from its global architecture. We propose an approach where we summarize anatomical information through dendritic geometry and density distributions which we use to calculate the connection probability between mitral and granule cells, while capturing activity patterns of each cell type in the neural dynamical systems theory of Izhikevich. In this way, we generate an efficient, anatomically and physiologically realistic large-scale model of the olfactory bulb network. Our model reproduces known connectivity between sister vs. non-sister mitral cells; measured patterns of lateral inhibition; and theta, beta, and gamma oscillations. The model in turn predicts testable relationships between network structure and several functional properties, including lateral inhibition, odor pattern decorrelation, and LFP oscillation frequency. We use the model to explore the influence of cortex on the olfactory bulb, demonstrating possible mechanisms by which cortical feedback to mitral cells or granule cells can influence bulbar activity, as well as how neurogenesis can improve bulbar decorrelation without requiring cell death. Our methodology provides a tractable tool for other researchers.
Strategies for meiotic sex chromosome dynamics and telomeric elongation in Marsupials
Authors: Marín-Gual Laia , González-Rodelas Laura , Pujol Gala , Vara Covadonga , Martín-Ruiz Marta , Berríos Soledad , Fernández-Donoso Raúl , Pask Andrew , Renfree Marilyn B. , Page Jesús , Waters Paul D. , Ruiz-Herrera Aurora
Published: February 2022

During meiotic prophase I, homologous chromosomes pair, synapse and recombine in a tightly regulated process that ensures the generation of genetically variable haploid gametes. Although the mechanisms underlying meiotic cell division have been well studied in model species, our understanding of the dynamics of meiotic prophase I in non-traditional model mammals remains in its infancy. Here, we reveal key meiotic features in previously uncharacterised marsupial species (the tammar wallaby and the fat-tailed dunnart), plus the fat-tailed mouse opossum, with a focus on sex chromosome pairing strategies, recombination and meiotic telomere homeostasis. We uncovered differences between phylogroups with important functional and evolutionary implications. First, sex chromosomes, which lack a pseudo-autosomal region in marsupials, had species specific pairing and silencing strategies, with implications for sex chromosome evolution. Second, we detected two waves of γH2AX accumulation during prophase I. The first wave was accompanied by low γH2AX levels on autosomes, which correlated with the low recombination rates that distinguish marsupials from eutherian mammals. In the second wave, γH2AX was restricted to sex chromosomes in all three species, which correlated with transcription from the X in tammar wallaby. This suggests non-canonical functions of γH2AX on meiotic sex chromosomes. Finally, we uncover evidence for telomere elongation in primary spermatocytes of the fat-tailed dunnart, a unique strategy within mammals. Our results provide new insights into meiotic progression and telomere homeostasis in marsupials, highlighting the importance of capturing the diversity of meiotic strategies within mammals.
Cooperativity of catalytic and lectin-like domain of Trypanosoma congolense trans-sialidase modulates its catalytic activity
Authors: Waespy Mario , Gbem Thaddeus Termulun , Dinesh Kumar Nilima , Solaiyappan Mani Shanmugam , Rosenau Jana , Dietz Frank , Kelm Sørge
Published: February 2022

Trans-sialidases (TS) represent a multi-gene family of unusual enzymes, which catalyse the transfer of terminal sialic acids (Sia) from sialoglycoconjugates to terminal galactose or N-acetylgalactosamine residues of oligosaccharides without the requirement of CMP-Neu5Ac, the activated Sia used by typical sialyltransferases. Enzymes comprise a N-terminal catalytic domain (CD) followed by a lectin-like domain (LD). Most work on trypanosomal TS has been done on enzymatic activities focusing on the CD of TS from Trypanosoma cruzi (causing Chagas disease in Latin America), subspecies of Trypanosoma brucei, (causing human sleeping sickness in Africa) and Trypanosoma congolense (causing African Animal Trypanosomosis in livestock). Previously, we demonstrated that T. congolense TS (TconTS)-LD binds to several carbohydrates, such as 1,4-β-mannotriose. In this study we investigated the influence of TconTS3-LD on Sia transfer efficiency of TconTS1a-CD by swapping domains. in silico analysis on structure models of TconTS enzymes revealed the potential of domain swaps between TconTS1a and TconTS3 without structural disruptions of the enzymes overall topologies. Recombinant domain swapped TconTS1a/TS3 showed clear Sia transfer activity, when using fetuin and lactose as Sia donor and acceptor substrates, respectively. While Sia transfer activity remained unchanged from the level of TconTS1a, hydrolytic release of free Neu5Ac as a side product was suppressed resulting in increased transfer efficiency. Presence of 1,4-β-mannotriose during TS reactions modulates enzyme activities enhancing transfer efficiency possibly due to occupation of the binding site in TconTS1a-LD. Interestingly this effect was in the same range as that observed when swapping TconTS1a-CD and TconTS3-LD. In summary, this study demonstrate the proof-of-principle for swapping CDs and LDs of TconTS and that TconTS3-LD influences enzymatic activity of TconTS1a-CD providing evidence that LDs play pivotal roles in modulating activities and biological functions of TconTS and possibly other TS.
On the resilience of health systems: A methodological exploration across countries in the WHO African Region
Authors: Karamagi Humphrey Cyprian , Titi-Ofei Regina , Kipruto Hillary Kipchumba , Seydi Aminata Benitou-Wahebine , Droti Benson , Talisuna Ambrose , Tsofa Benjamin , Saikat Sohel , Schmets Gerard , Barasa Edwine , Tumusiime Prosper , Makubalo Lindiwe , Cabore Joseph Waogodo , Moeti Matshidiso
Published: February 2022

The need for resilient health systems is recognized as important for the attainment of health outcomes, given the current shocks to health services. Resilience has been defined as the capacity to “prepare and effectively respond to crises; maintain core functions; and, informed by lessons learnt, reorganize if conditions require it”. There is however a recognized dichotomy between its conceptualization in literature, and its application in practice. We propose two mutually reinforcing categories of resilience, representing resilience targeted at potentially known shocks, and the inherent health system resilience, needed to respond to unpredictable shock events. We determined capacities for each of these categories, and explored this methodological proposition by computing country-specific scores against each capacity, for the 47 Member States of the WHO African Region. We assessed face validity of the computed index, to ensure derived values were representative of the different elements of resilience, and were predictive of health outcomes, and computed bias-corrected non-parametric confidence intervals of the emergency preparedness and response (EPR) and inherent system resilience (ISR) sub-indices, as well as the overall resilience index, using 1000 bootstrap replicates. We also explored the internal consistency and scale reliability of the index, by calculating Cronbach alphas for the various proposed capacities and their corresponding attributes. We computed overall resilience to be 48.4 out of a possible 100 in the 47 assessed countries, with generally lower levels of ISR. For ISR, the capacities were weakest for transformation capacity, followed by mobilization of resources, awareness of own capacities, self-regulation and finally diversity of services respectively. This paper aims to contribute to the growing body of empirical evidence on health systems and service resilience, which is of great importance to the functionality and performance of health systems, particularly in the context of COVID-19. It provides a methodological reflection for monitoring health system resilience, revealing areas of improvement in the provision of essential health services during shock events, and builds a case for the need for mechanisms, at country level, that address both specific and non-specific shocks to the health system, ultimately for the attainment of improved health outcomes.
Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum)
Authors: Lam Ivan P. Y. , Sung Yik-Hei , Fong Jonathan J.
Published: February 2022

We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.
A proximity-based in silico approach to identify redox-labile disulfide bonds: The example of FVIII
Authors: Arsiccio Andrea , Metcalfe Clive , Pisano Roberto , Raut Sanj , Coxon Carmen
Published: February 2022

Allosteric disulfide bonds permit highly responsive, transient ‘switch-like’ properties that are ideal for processes like coagulation and inflammation that require rapid and localised responses to damage or injury. Haemophilia A (HA) is a rare bleeding disorder managed with exogenous coagulation factor(F) VIII products. FVIII has eight disulfide bonds and is known to be redox labile, but it is not known how reduction/oxidation affects the structure-function relationship, or its immunogenicity—a serious complication for 30% severe HA patients. Understanding how redox-mediated changes influence FVIII can inform molecular engineering strategies aimed at improving activity and stability, and reducing immunogenicity. FVIII is a challenging molecule to work with owing to its poor expression and instability so, in a proof-of-concept study, we used molecular dynamics (MD) to identify which disulfide bonds were most likely to be reduced and how this would affect structure/function; results were then experimentally verified. MD identified Cys1899-Cys1903 disulfide as the most likely to undergo reduction based on energy and proximity criteria. Further MD suggested this reduction led to a more open conformation. Here we present our findings and highlight the value of MD approaches.
Perceptions of cervical cancer and motivation for screening among women in Rural Lilongwe, Malawi: A qualitative study
Authors: Bula Agatha K. , Lee Fan , Chapola John , Mapanje Clement , Tsidya Mercy , Thom Annie , Tang Jennifer H. , Chinula Lameck
Published: February 2022

Introduction

Cervical cancer is the leading cause of cancer death among women in Malawi. Low awareness of cervical cancer and negative perceptions of screening can prevent women from participating in preventative strategies. We sought to explore perceptions and motivations for screening among women who participated in a cervical cancer screen-and-treat pilot study in rural Malawi.

Materials and methods

We conducted a qualitative sub-study of a community-based cervical cancer screen-and-treat pilot study in rural Lilongwe between July-August 2017. From October 2017-February 2018, 17 women who underwent screening using visual inspection with acetic acid (VIA) and same-day thermal ablation treatment were recruited at their 12-week follow-up visit post treatment to participate in this qualitative sub-study. Semi-structured interview guides that explored baseline knowledge of cervical cancer, perceptions, and motivation for screening were used for in-depth interviews (IDIs). IDIs were conducted in the local language, Chichewa, translated and transcribed to English. Data was analyzed using NVivo®V12.0.

Results

Findings included fatalistic views on cancer, but limited knowledge specific to cervical cancer. Misconceptions of cervical cancer screening were common; however, there was a unique understanding of screening as prevention (i.e., finding and treating early disease to prevent progression to worsening disease). This understanding appeared to stem from HIV prevention concepts known to the community. Motivations for screening included desire to know one’s health status, convenience of community-based screening, and peer encouragement.

Conclusion

Despite limited knowledge of cervical cancer and misconceptions of screening, the concept of screening for prevention, desire to know one’s health status, convenient access, and peers’ influence were motivators for participation in screening. Cervical cancer screen-and-treat programs in high HIV prevalence areas should consider utilizing language that parallels HIV prevention language to communicate the need for cervical cancer screening and treatment and utilize prevention concepts that may already be familiar to women living there.
Allergy to Peanuts imPacting Emotions And Life (APPEAL): The impact of peanut allergy on children, teenagers, adults and caregivers in the UK and Ireland
Authors: Tsoumani Marina , Regent Lynne , Warner Amena , Gallop Katy , Patel Ram , Ryan Robert , Vereda Andrea , Acaster Sarah , DunnGalvin Audrey , Byrne Aideen
Published: February 2022

The Allergy to Peanuts imPacting Emotions And Life study (APPEAL) explored the psychosocial burden of living with self-reported peanut allergy experienced by children, teenagers, adults and caregivers in the UK and Ireland. A two-stage (quantitative survey and qualitative interview [APPEAL-1]), cross-sectional study of the psychosocial burden of peanut allergy (APPEAL-2) was conducted. Quantitative data were evaluated using descriptive statistics and qualitative data were analysed using MAXQDA software. A conceptual model specific to UK and Ireland was developed using the concepts identified during the analysis. A total of 284 adults in the UK and Ireland completed the APPEAL-1 survey and 42 individuals participated in APPEAL-2. Respondents reported that peanut allergy restricts their choices in various situations, especially with regard to choosing food when eating out (87% moderately or severely restricted), choosing where to eat (82%), special occasions (76%) and when buying food from a shop (71%). Fifty-two percent of survey participants and 40% of interview participants reported being bullied because of PA. Psychological impact of peanut allergy included feeling at least moderate levels of frustration (70%), uncertainty (79%), and stress (71%). The qualitative analysis identified three different types of coping strategies (daily monitoring or vigilance, communication and planning) and four main areas of individuals’ lives that are impacted by peanut allergy (social activities, relationships, emotions and work [adults and caregivers only]). The extent of the impact reported varied substantially between participants, with some reporting many negative consequences of living with peanut allergy and others feeling it has minimal impact on their health-related quality of life. This large survey and interview study highlight the psychosocial burden of peanut allergy for adults, teenagers, children and caregivers in the UK and Ireland. The analysis demonstrates the wide variation in level of impact of peanut allergy and the unmet need for those individuals who experience a substantial burden from living with peanut allergy.
Sources of genomic diversity in the self-fertile plant pathogen, Sclerotinia sclerotiorum, and consequences for resistance breeding
Authors: Buchwaldt Lone , Garg Harsh , Puri Krishna D. , Durkin Jonathan , Adam Jennifer , Harrington Myrtle , Liabeuf Debora , Davies Alan , Hegedus Dwayne D. , Sharpe Andrew G. , Gali Krishna Kishore
Published: February 2022

The ascomycete, Sclerotinia sclerotiorum, has a broad host range and causes yield loss in dicotyledonous crops world wide. Genomic diversity was determined in a population of 127 isolates obtained from individual canola (Brassica napus) fields in western Canada. Genotyping with 39 simple sequence repeat (SSR) markers revealed each isolate was a unique haplotype. Analysis of molecular variance showed 97% was due to isolate and 3% due to geographical location. Testing of mycelium compatibility among 133 isolates identified clones of mutually compatible isolates with 86–95% similar SSR haplotype, whereas incompatible isolates were highly diverse. In the Province of Manitoba, 61% of isolates were compatible forming clones and stings of pairwise compatible isolates not described before. In contrast, only 35% of isolates were compatible in Alberta without forming clones and strings, while 39% were compatible in Saskatchewan with a single clone, but no strings. These difference can be explained by wetter growing seasons and more susceptible crop species in Manitoba favouring frequent mycelium interaction and more life cycles over time, which might also explain similar differences observed in other geographical areas and host crops. Analysis of linkage disequilibrium rejected random recombination, consistent with a self-fertile fungus, restricted outcrossing due to mycelium incompatibility, and only a single annual opportunity for genomic recombination during meiosis in the ascospore stage between non-sister chromatids in the rare event nuclei from different isolates come together. More probable sources of genomic diversity is slippage during DNA replication and point mutation affecting single nucleotides that accumulate and likely increase mycelium incompatibility in a population over time. A phylogenetic tree based on SSR haplotype grouped isolates into 17 sub-populations. Aggressiveness was tested by inoculating one isolate from each sub-population onto B. napus lines with quantitative resistance. Analysis of variance was significant for isolate, line, and isolate by line interaction. These isolates represent the genomic and pathogenic diversity in western Canada, and are suitable for resistance screening in canola breeding programs.
Burden and risk factors for antenatal depression and its effect on preterm birth in South Asia: A population-based cohort study
Authors: Khanam Rasheda , Applegate Jennifer , Nisar Imran , Dutta Arup , Rahman Sayedur , Nizar Ambreen , Ali Said Mohammed , Chowdhury Nabidul Haque , Begum Farzana , Dhingra Usha , Tofail Fahmida , Mehmood Usma , Deb Saikat , Ahmed Salahuddin , Muhammad Sajid , Das Sayan , Ahmed Saifuddin , Mittal Harshita , Minckas Nicole , Yoshida Sachiyo , Bahl Rajiv , Jehan Fyezah , Sazawal Sunil , Baqui Abdullah H.
Published: February 2022

Introduction

Women experience high rates of depression, particularly during pregnancy and the postpartum periods. Using population-based data from Bangladesh and Pakistan, we estimated the burden of antenatal depression, its risk factors, and its effect on preterm birth.

Methods

The study uses the following data: maternal depression measured between 24 and 28 weeks of gestation using the 9–question Patient Health Questionnaire (PHQ-9); data on pregnancy including an ultrasound before 19 weeks of gestation; data on pregnancy outcomes; and data on woman’s age, education, parity, weight, height, history of previous illness, prior miscarriage, stillbirth, husband’s education, and household socioeconomic data collected during early pregnancy. Using PHQ-9 cutoff score of ≥12, women were categorized into none to mild depression or moderate to moderately severe depression. Using ultrasound data, preterm birth was defined as babies born <37 weeks of gestation. To identify risk ratios (RR) for antenatal depression, unadjusted and adjusted RR and 95% confidence intervals (CI) were calculated using log- binomial model. Log-binomial models were also used for determining the effect of antenatal depression on preterm birth adjusting for potential confounders. Data were analyzed using Stata version 16 (StataCorp LP).

Results

About 6% of the women reported moderate to moderately severe depressive symptoms during the antenatal period. A parity of ≥2 and the highest household wealth status were associated with an increased risk of depression. The overall incidence of preterm birth was 13.4%. Maternal antenatal depression was significantly associated with the risk of preterm birth (ARR, 95% CI: 1.34, 1.02–1.74).

Conclusion

The increased risk of preterm birth in women with antenatal depression in conjunction with other significant risk factors suggests that depression likely occurs within a constellation of other risk factors. Thus, to effectively address the burden of preterm birth, programs require developing and providing integrated care addressing multiple risk factors.
The clinical impact of concomitant medication use on the outcome of postoperative recurrent non-small-cell lung cancer in patients receiving immune checkpoint inhibitors
Authors: Takada Kazuki , Shimokawa Mototsugu , Takamori Shinkichi , Shimamatsu Shinichiro , Hirai Fumihiko , Ono Yuki , Tagawa Tetsuzo , Okamoto Tatsuro , Hamatake Motoharu , Okamoto Isamu , Mori Masaki
Published: February 2022

A recent study suggested that proton pump inhibitor (PPI) use in patients with advanced non-small-cell lung cancer (NSCLC) receiving immune checkpoint inhibitors (ICIs) was associated with poor clinical outcomes. However, the clinical impact of PPI use on the outcome of patients receiving ICIs for postoperative recurrent NSCLC is unknown. The outcomes of 95 patients with postoperative recurrence of NSCLC receiving ICIs at 3 medical centers in Japan were analyzed. We conducted adjusted Kaplan–Meier survival analyses with the log-rank test, a Cox proportional hazards regression analysis, and a logistic regression analysis using inverse probability of treatment weighting (IPTW) to minimize the bias arising from the patients’ backgrounds. The IPTW-adjusted Kaplan–Meier curves revealed that the progression-free survival (PFS), but not the overall survival (OS), was significantly longer in patients who did not receive PPIs than in those who did receive them. The IPTW-adjusted Cox regression analysis revealed that PPI use was an independent poor prognostic factor for the PFS and OS. Furthermore, in the IPTW-adjusted logistic regression analysis, PPI non-use was an independent predictor of disease control. In this multicenter and retrospective study, PPI use was associated with poor clinical outcomes in patients with postoperative recurrence of NSCLC who were receiving ICIs. PPIs should not be prescribed indiscriminately to patients with postoperative recurrence of NSCLC who intend to receive ICIs. These findings should be validated in a future prospective study.
Algorithm for wireless sensor networks in ginseng field in precision agriculture
Authors: Li Changcheng , Chen Deyun , Xie Chengjun , Tang You
Published: February 2022

In the research on energy-efficient networking methods for precision agriculture, a hot topic is the energy issue of sensing nodes for individual wireless sensor networks. The sensing nodes of the wireless sensor network should be enabled to provide better services with limited energy to support wide-range and multi-scenario acquisition and transmission of three-dimensional crop information. Further, the life cycle of the sensing nodes should be maximized under limited energy. The transmission direction and node power consumption are considered, and the forward and high-energy nodes are selected as the preferred cluster heads or data-forwarding nodes. Taking the cropland cultivation of ginseng as the background, we put forward a particle swarm optimization-based networking algorithm for wireless sensor networks with excellent performance. This algorithm can be used for precision agriculture and achieve optimal equipment configuration in a network under limited energy, while ensuring reliable communication in the network. The node scale is configured as 50 to 300 nodes in the range of 500 × 500 m2, and simulated testing is conducted with the LEACH, BCDCP, and ECHERP routing protocols. Compared with the existing LEACH, BCDCP, and ECHERP routing protocols, the proposed networking method can achieve the network lifetime prolongation and mitigate the decreased degree and decreasing trend of the distance between the sensing nodes and center nodes of the sensor network, which results in a longer network life cycle and stronger environment suitability. It is an effective method that improves the sensing node lifetime for a wireless sensor network applied to cropland cultivation of ginseng.
Improvement of DBR routing protocol in underwater wireless sensor networks using fuzzy logic and bloom filter
Authors: Karimi Hamed , Khamforoosh Keyhan , Maihami Vafa
Published: February 2022

Routing protocols for underwater wireless sensor networks (UWSN) and underwater Internet of Things (IoT_UWSN) networks have expanded significantly. DBR routing protocol is one of the most critical routing protocols in UWSNs. In this routing protocol, the energy consumption of the nodes, the rate of loss of sent packets, and the rate of drop of routing packets due to node shutdown have created significant challenges. For this purpose, in a new scenario called FB-DBR, clustering is performed, and fuzzy logic and bloom filter are used in each cluster’s new routing protocol in underwater wireless sensor networks. Due to the fuzzy nature of the parameters used in DBR, better results are obtained and bloom filters are used in routing tables to compensate for the deceleration. as the average number of accesses to routing table entries, dead nodes, Number of Packets Sent to Base Station (BS), Number of Packets Received at BS, Packet Dropped, and Remaining Energy has improved significantly.
Comparison of individual hive and apiary-level sample types for spores of Paenibacillus larvae in Saskatchewan honey bee operations
Authors: Zabrodski Michael W. , DeBruyne Jessica E. , Wilson Geoff , Moshynskyy Igor , Sharafi Mohsen , Wood Sarah C. , Kozii Ivanna V. , Thebeau Jenna , Klein Colby D. , Medici de Mattos Igor , Sobchishin LaRhonda , Epp Tasha , Ruzzini Antonio C. , Simko Elemir
Published: February 2022

Three commercial honey bee operations in Saskatchewan, Canada, with outbreaks of American foulbrood (AFB) and recent or ongoing metaphylactic antibiotic use were intensively sampled to detect spores ofPaenibacillus larvaeduring the summer of 2019. Here, we compared spore concentrations in different sample types within individual hives, assessed the surrogacy potential of honey collected from honey supers in place of brood chamber honey or adult bees within hives, and evaluated the ability of pooled, extracted honey to predict the degree of spore contamination identified through individual hive testing. Samples of honey and bees from hives within apiaries with a recent, confirmed case of AFB in a single hive (index apiaries) and apiaries without clinical evidence of AFB (unaffected apiaries), as well as pooled, apiary-level honey samples from end-of-season extraction, were collected and cultured to detect and enumerate spores. Only a few hives were heavily contaminated by spores in any given apiary. All operations were different from one another with regard to both the overall degree of spore contamination across apiaries and the distribution of spores between index apiaries and unaffected apiaries. Within operations, individual hive spore concentrations in unaffected apiaries were significantly different from index apiaries in the brood chamber (BC) honey, honey super (HS) honey, and BC bees of one of three operations. Across all operations, BC honey was best for discriminating index apiaries from unaffected apiaries (p = 0.001), followed by HS honey (p = 0.06), and BC bees (p = 0.398). HS honey positively correlated with both BC honey (rs= 0.76, p < 0.0001) and bees (rs= 0.50, p < 0.0001) and may be useful as a surrogate for either. Spore concentrations in pooled, extracted honey seem to have predictive potential for overall spore contamination within each operation and may have prognostic value in assessing the risk of future AFB outbreaks at the apiary (or operation) level.