bluuebunny/crossref_metadata_2025 huggingface dataset:
Tailoring resistive switching in epitaxial SrCoO2.5 films by irradiation induced uniaxial strain
Authors: Xiang Xuepeng , Rao Jingjing , He Zuyun , Zhou Mengzhen , Huang Qicheng , Gao Yuan , Fan Zhen , Wang Xinwei , Chen Yan
Published: July 2022

Strain engineering has been widely applied to tune the performance of oxide thin film based devices. To precisely regulate the strain state of the thin film, nevertheless, still remains a challenging task. Herein, we demonstrate that the uniaxial strain along the c-axis of epitaxial SrCoO2.5 (SCO) (001) thin film can be continuously controlled by low-energy helium (He) irradiation (5 keV), leading to noticeable enhancement in resistive switching (RS) performance. All the irradiated SCO thin films exhibit out-of-plane tensile strain due to the implanted He interstitials in the lattice, and the strain increases linearly from 0.447% to 2.785% as the ion fluence increases from 1 × 1014 to 1 × 1015 ion/cm2. Although all the irradiated SCO-based devices follow similar conductive filaments mechanism as the pristine device, the performance shows a volcano shape dependence on the irradiation fluence. The device subjected to irradiation of 1 × 1014 ion/cm2 shows the optimal performance with the highest ON/OFF ratio and good endurance. Such dependence of RS behavior on irradiation-induced uniaxial strain is attributed to the widely observed nonlinear dependence of oxygen migration on the elastic tensile strain. Our results provide an effective strategy to regulate the strain states and the correlating functionality of oxide thin films.
Water entry dynamics of rough microstructured spheres
Authors: Wang Zhaochang , Tao Tongtong , Zhu Yongqing , Hu Xidong , Guo Yuhang , Ji Jiawei , Liu Xiaojun , Liu Kun , Jiao Yunlong
Published: July 2022

In this work, we proposed a facile underwater air cavity generation strategy based on rough microstructured spheres and explored its water entry dynamics and drag reduction characteristics. Under the assistance of microstructures, the three-phase contact line is pinned near the sphere equator and inhibits the wetting of the liquid film along the sphere surface, so that leading the formation of air cavity. The water entry process is mainly divided into four stages: flow formation, cavity opening and stretching, cavity closure and entrapment, and cavity collapse. With the Froude number Fr, the pinch-off depth of air cavity obviously increases, and the pinch-off time is also delayed, which contributes to the formation of a longer bottom air cavity. In addition, the spheres with a larger impact velocity would fall faster in water during the initial falling period, while the terminal velocities are nearly the same for all the spheres when they are in a stable falling period. It is worth noting that for a same sphere, the larger impact velocity could not only contribute to the formation of a longer air cavity but also makes the generated air cavity keep in a stable and streamlined shape at different underwater depth, which is vitally important for achieving continuous drag reduction. Finally, we demonstrated numerically that the stable streamlined sphere-in-cavity structure could reduce the hydrodynamic resistance levels up to 91.3% at Re ∼ 3.12 × 104, which is related to the boundary slip caused by an air layer trapped in the microstructures.
Coordinated NADPH oxidase/hydrogen peroxide functions regulate cutaneous sensory axon de- and regeneration
Authors: Cadiz Diaz Antonio , Schmidt Natalie A. , Yamazaki Mamiko , Hsieh Chia-Jung , Lisse Thomas S. , Rieger Sandra
Published: July 2022

Tissue wounding induces cutaneous sensory axon regeneration via hydrogen peroxide (H2O2) that is produced by the epithelial NADPH oxidase, Duox1. Sciatic nerve injury instead induces axon regeneration through neuronal uptake of the NADPH oxidase, Nox2, from macrophages. We therefore reasoned that the tissue environment in which axons are damaged stimulates distinct regenerative mechanisms. Here, we show that cutaneous axon regeneration induced by tissue wounding depends on both neuronal and keratinocyte-specific mechanisms involving H2O2signaling. Genetic depletion of H2O2in sensory neurons abolishes axon regeneration, whereas keratinocyte-specific H2O2depletion promotes axonal repulsion, a phenotype mirrored induox1mutants. Intriguingly,cybamutants, deficient in the essential Nox subunit, p22Phox, retain limited axon regenerative capacity but display delayed Wallerian degeneration and axonal fusion, observed so far only in invertebrates. We further show that keratinocyte-specific oxidation of the epidermal growth factor receptor (EGFR) at a conserved cysteine thiol (C797) serves as an attractive cue for regenerating axons, leading to EGFR-dependent localized epidermal matrix remodeling via the matrix-metalloproteinase, MMP-13. Therefore, wound-induced cutaneous axon de- and regeneration depend on the coordinated functions of NADPH oxidases mediating distinct processes following injury.
Assortative mating enhances postzygotic barriers to gene flow via ancestry bundling
Authors: Muralidhar Pavitra , Coop Graham , Veller Carl
Published: July 2022

Hybridization and subsequent genetic introgression are now known to be common features of the histories of many species, including our own. Following hybridization, selection often purges introgressed DNA genome-wide. While assortative mating can limit hybridization in the first place, it is also known to play an important role in postzygotic selection against hybrids and, thus, the purging of introgressed DNA. However, this role is usually thought of as a direct one: a tendency for mates to be conspecific reduces the sexual fitness of hybrids, reducing the transmission of introgressed ancestry. Here, we explore a second, indirect role of assortative mating as a postzygotic barrier to gene flow. Under assortative mating, parents covary in their ancestry, causing ancestry to be “bundled” in their offspring and later generations. This bundling effect increases ancestry variance in the population, enhancing the efficiency with which postzygotic selection purges introgressed DNA. Using whole-genome simulations, we show that the bundling effect can comprise a substantial portion of mate choice’s overall effect as a postzygotic barrier to gene flow. We then derive a simple method for estimating the impact of the bundling effect from standard metrics of assortative mating. Applying this method to data from a diverse set of hybrid zones, we find that the bundling effect increases the purging of introgressed DNA by between 1.2-fold (in a baboon system with weak assortative mating) and 14-fold (in a swordtail system with strong assortative mating). Thus, assortative mating’s bundling effect contributes substantially to the genetic isolation of species.
Structural basis for high-voltage activation and subtype-specific inhibition of human Nav1.8
Authors: Huang Xiaoshuang , Jin Xueqin , Huang Gaoxingyu , Huang Jian , Wu Tong , Li Zhangqiang , Chen Jiaofeng , Kong Fang , Pan Xiaojing , Yan Nieng
Published: July 2022

The dorsal root ganglia–localized voltage-gated sodium (Nav) channel Nav1.8 represents a promising target for developing next-generation analgesics. A prominent characteristic of Nav1.8 is the requirement of more depolarized membrane potential for activation. Here we present the cryogenic electron microscopy structures of human Nav1.8 alone and bound to a selective pore blocker, A-803467, at overall resolutions of 2.7 to 3.2 Å. The first voltage-sensing domain (VSDI) displays three different conformations. Structure-guided mutagenesis identified the extracellular interface between VSDIand the pore domain (PD) to be a determinant for the high-voltage dependence of activation. A-803467 was clearly resolved in the central cavity of the PD, clenching S6IV. Our structure-guided functional characterizations show that two nonligand binding residues, Thr397 on S6Iand Gly1406 on S6III, allosterically modulate the channel’s sensitivity to A-803467. Comparison of available structures of human Navchannels suggests the extracellular loop region to be a potential site for developing subtype-specific pore-blocking biologics.
A CMV-induced adaptive human Vδ1+ γδ T cell clone recognizes HLA-DR
Authors: Deseke Malte , Rampoldi Francesca , Sandrock Inga , Borst Eva , Böning Heike , Ssebyatika George Liam , Jürgens Carina , Plückebaum Nina , Beck Maleen , Hassan Ahmed , Tan Likai , Demera Abdi , Janssen Anika , Steinberger Peter , Koenecke Christian , Viejo-Borbolla Abel , Messerle Martin , Krey Thomas , Prinz Immo
Published: July 2022

The innate and adaptive roles of γδ T cells and their clonal γδ T cell receptors (TCRs) in immune responses are still unclear. Recent studies of γδ TCR repertoire dynamics showed massive expansion of individual Vδ1+ γδ T cell clones during viral infection. To judge whether such expansion is random or actually represents TCR-dependent adaptive immune responses, information about their cognate TCR ligands is required. Here, we used CRISPR/Cas9-mediated screening to identify HLA-DRA, RFXAP, RFX5, and CIITA as required for target cell recognition of a CMV-induced Vγ3Vδ1+ TCR, and further characterization revealed a direct interaction of this Vδ1+ TCR with the MHC II complex HLA-DR. Since MHC II is strongly upregulated by interferon-γ, these results suggest an inflammation-induced MHC-dependent immune response of γδ T cells.
Spatial population genetics with fluid flow
Authors: Benzi Roberto , Nelson David R , Shankar Suraj , Toschi Federico , Zhu Xiaojue
Published: July 2022

The growth and evolution of microbial populations is often subjected to advection by fluid flows in spatially extended environments, with immediate consequences for questions of spatial population genetics in marine ecology, planktonic diversity and origin of life scenarios. Here, we review recent progress made in understanding this rich problem in the simplified setting of two competing genetic microbial strains subjected to fluid flows. As a pedagogical example we focus on antagonsim, i.e., two killer microorganism strains, each secreting toxins that impede the growth of their competitors (competitive exclusion), in the presence of stationary fluid flows. By solving two coupled reaction–diffusion equations that include advection by simple steady cellular flows composed of characteristic flow motifs in two dimensions (2D), we show how local flow shear and compressibility effects can interact with selective advantage to have a dramatic influence on genetic competition and fixation in spatially distributed populations. We analyze several 1D and 2D flow geometries including sources, sinks, vortices and saddles, and show how simple analytical models of the dynamics of the genetic interface can be used to shed light on the nucleation, coexistence and flow-driven instabilities of genetic drops. By exploiting an analogy with phase separation with nonconserved order parameters, we uncover how these genetic drops harness fluid flows for novel evolutionary strategies, even in the presence of number fluctuations, as confirmed by agent-based simulations as well.
Compulsory Licences in a Regional Context: An Appraisal of the TRIPS Amendment’s Special Regional Treatment
Authors: Adekola Tolulope Anthony
Published: July 2022

Against the backdrop of the regional mechanism carved out under Art. 31bis(3) of the TRIPS Agreement for issuing compulsory licences, the paper critically appraises the mechanism’s viability or otherwise in addressing the challenge of access to essential medicines in a regional context. The paper finds that the mechanism remains severely restricted. First, it does not exempt an importing country within the regional alliance from issuing a separate compulsory licence where a patent is in force on the pharmaceutical product in question. Second, the logic of the mechanism is counterintuitive in that it is prohibited from being used as an instrument to pursue industrial policy objectives, and in a broad sense, a public-health-related industrial agenda. Using the East African Community (EAC) as a case study, the paper practically reveals how the identified distortions inhibit the use of compulsory licences within a regional coalition. The paper also examines how the potency of the TRIPS transition period, which excludes 80% of EAC member states from granting pharmaceuticals patents until 2034, is being whittled down by the African Regional Intellectual Property Organization’s (ARIPO) obligations and unclear domestic legislation. The paper recommends an overhaul of the TRIPS amendment’s regional mechanism for better effectiveness in driving pharmaceutical access.
Classification of Fermi-LAT unidentified gamma-ray sources using catboost gradient boosting decision trees
Authors: Coronado-Blázquez Javier
Published: July 2022

The latest Fermi-LAT gamma-ray catalogue, 4FGL-DR3, presents a large fraction of sources without clear association to known counterparts, i.e. unidentified sources (unIDs). In this paper, we aim to classify them using machine learning algorithms, which are trained with the spectral characteristics of associated sources to predict the class of the unID population. With the state-of-the-art catboost algorithm, based on gradient boosting decision trees, we are able to reach a 67 per cent accuracy on a 23-class data set. Removing a single of these classes – blazars of uncertain type – increases the accuracy to 81 per cent. If interested only in a binary AGN/pulsar distinction, the model accuracy is boosted up to 99 per cent. Additionally, we perform an unsupervised search among both known and unID population, and try to predict the number of clusters of similar sources, without prior knowledge of their classes. The full code used to perform all calculations is provided as an interactive python notebook.
Physics of nova outbursts: A theoretical model of classical nova outbursts with self-consistent wind mass loss
Authors: Kato Mariko , Saio Hideyuki , Hachisu Izumi
Published: July 2022

We present a model for one cycle of a classical nova outburst based on a self-consistent wind mass loss accelerated by the gradient of radiation pressure, i.e., so-called optically thick winds. Evolution models are calculated by a Henyey code for a 1.0 $M_{\odot }$ white dwarf with a mass-accretion rate of 5 × 10−9 $M_{\odot }$ yr−1. The outermost part of the hydrogen-rich envelope is connected to a steadily moving envelope where optically thick winds occur. We confirm that no internal shock waves occur at thermonuclear runaway. The wind mass-loss rate reaches a peak of 1.4 × 10−4 $M_{\odot }$ yr−1 at the epoch of the maximum photospheric expansion, where the photospheric temperature decreases to log Tph (K) = 3.90. Almost all of the accreted mass is lost in the wind. The nuclear energy generated in hydrogen burning is lost in a form of photon emission (64%), gravitational energy (lifting up the wind matter against gravity, 35%), and the kinetic energy of the wind (0.23%). A classical nova should be very bright in a far-UV (100–300 Å) band for one day just after the onset of thermonuclear runaway (∼ 25 d before the optical maximum). In the decay phase of the nova outburst, the envelope structure is very close to that of a steady-state solution.
Isolation of Streptomycin-Resistant Erwinia pyrifoliae in Korea
Authors: Lee M.-H. , Ham H. , Choi H.-W. , Park D. S.
Published: July 2022

As a black shoot blight disease-causing agent, Erwinia pyrifoliae was first reported in 1995 in Korea. A total of 101 isolates of E. pyrifoliae were isolated from samples showing bacterial symptoms collected from apple and pear orchards between 2020 and 2021. These isolates were screened for streptomycin resistance, with one from an orchard in Gwangju showing resistance at 100 μg/ml streptomycin. This streptomycin-resistant E. pyrifoliae (EpSmR) isolate was identified via polymerase chain reaction amplification of the strA/strB gene and an internal region of the ribosomal rpsL gene containing codon 43. EpSmR has a point mutation that altered this codon from lysine (AAA) to threonine (ACA). The strA and strB genes were not identified in EpSmR. EpSmR showed a high resistance to streptomycin (>50,000 μg/ml). This is the first study reporting EpSmR, which emerged due to a mutation in codon 43 of the rpsL gene.
Secondary prevention of latex allergy
Authors: Nettis Eustachio , Casella Rossella , Incorvaia Cristoforo , Miniello Andrea
Published: July 2022

Purpose of review

The present review addresses the secondary prevention in healthcare worker, healthcare setting, and in patients outside the healthcare setting.

Recent findings

There is sufficient knowledge of the broad aetiology of latex allergy for secondary preventive programmes to be widely adopted. Currently, avoidance of latex-containing surgical products is mandatory in the care of sensitized patients. They should also have a list of occult sources of natural rubber latex exposure and cross-reacting fruits. During all health-care procedures latex allergic patients should be treated in a ‘latex-free’ environment. Specific sublingual immunotherapy has been suggested as a suitable therapeutic option. It can be offered, in addition to symptomatic treatment, to selected patients, when avoidance measures are not feasible or effective. The use of omalizumab could also be extended as an adjunct to latex immunotherapy.

Despite of the progress made in the secondary prevention of latex allergy, the disease still continues to be a global health problem.
Depression Increases Posterior Cervical Decompression and Fusion Revision Rates and Diminishes Neck Disability Index Improvement
Authors: Toci Gregory R. , Lambrechts Mark J. , Karamian Brian A. , Mao Jennifer , Heinle Jeremy , Bhatt Shivang , Harlamova Daria , Canseco Jose A. , Kaye Ian David , Woods Barrett I. , Hilibrand Alan S. , Kepler Christopher K. , Vaccaro Alexander R. , Schroeder Gregory D.
Published: July 2022

Study Design.

A retrospective cohort study.

Objective.

To determine if depression and/or anxiety significantly affect patient-reported outcome measures (PROMs) after posterior cervical decompression and fusion (PCDF).

Summary of Background Data.

Mental health diagnoses are receiving increased recognition for their influence of outcomes after spine surgery. The magnitude that mental health disorders contribute to patient-reported outcomes following PCDF requires increased awareness and understanding.

Materials and Methods.

A review of electronic medical records identified patients who underwent a PCDF at a single institution during the years 2013–2020. Patients were placed into either depression/anxiety or nondepression/anxiety group based on their medical history. A delta score (∆) was calculated for all PROMs by subtracting postoperative from preoperative scores. χ2 tests and t tests were utilized to analyze categorical and continuous data, respectively. Regression analysis determined independent predictors of change in PROMs. Alpha was set at 0.05.

Results.

A total of 195 patients met inclusion criteria, with 60 (30.8%) having a prior diagnosis of depression/anxiety. The depression/anxiety group was younger (58.8 vs. 63.0, P=0.012), predominantly female (53.3% vs. 31.9%, P=0.007), and more frequently required revision surgery (11.7% vs. 0.74%, P=0.001). In addition, they had worse baseline mental component (MCS-12) (42.2 vs. 48.6, P<0.001), postoperative MCS-12 (46.5 vs. 52.9, P=0.002), postoperative neck disability index (NDI) (40.7 vs. 28.5, P=0.001), ∆NDI (−1.80 vs. −8.93, P=0.010), NDI minimum clinically important difference improvement (15.0% vs. 29.6%, P=0.046), and postoperative Visual Analog Scale (VAS) Neck scores (3.63 vs. 2.48, P=0.018). Only the nondepression/anxiety group improved in MCS-12 (P=0.002) and NDI (P<0.001) postoperatively. Depression and/or anxiety was an independent predictor of decreased magnitude of NDI improvement on regression analysis (β=7.14, P=0.038).

Conclusion.

Patients with history of depression or anxiety demonstrate less improvement in patient-reported outcomes and a higher revision rate after posterior cervical fusion, highlighting the importance of mental health on clinical outcomes after spine surgery.
Establishment of an Individualized Distal Junctional Kyphosis Risk Index following the Surgical Treatment of Adult Cervical Deformities
Authors: Passias Peter G. , Naessig Sara , Sagoo Navraj , Passfall Lara , Ahmad Waleed , Lafage Renaud , Lafage Virginie , Vira Shaleen , Schoenfeld Andrew J. , Oh Cheongeun , Protopsaltis Themistocles , Kim Han Jo , Daniels Alan , Hart Robert , Burton Douglas , Klineberg Eric O. , Bess Shay , Schwab Frank , Shaffrey Christopher , Ames Christopher P. , Smith Justin S. ,   On Behalf of the International Spine Study Group
Published: July 2022

Study Design.

A retrospective review of a multicenter comprehensive cervical deformity (CD) database.

Objective.

To develop a novel risk index specific to each patient to aid in patient counseling and surgical planning to minimize postop distal junctional kyphosis (DJK) occurrence.

Background.

DJK is a radiographic finding identified after patients undergo instrumented spinal fusions which can result in sagittal spinal deformity, pain and disability, and potentially neurological compromise. DJK is considered multifactorial in nature and there is a lack of consensus on the true etiology of DJK.

Materials and Methods.

CD patients with baseline (BL) and at least one-year postoperative radiographic follow-up were included. A patient-specific DJK score was created through use of unstandardized Beta weights of a multivariate regression model predicting DJK (end of fusion construct to the second distal vertebra change in this angle by <−10° from BL to postop).

Results.

A total of 110 CD patients included (61 yr, 66.4% females, 28.8 kg/m2). In all, 31.8% of these patients developed DJK (16.1% three males, 11.4% six males, 62.9% one-year). At BL, DJK patients were more frail and underwent combined approach more (both P<0.05). Multivariate model regression analysis identified individualized scores through creation of a DJK equation: −0.55+0.009 (BL inclination)−0.078 (preinflection)+5.9×10-5 (BL lowest instrumented vertebra angle) + 0.43 (combine approach)−0.002 (BL TS-CL)−0.002 (BL pelvic tilt)−0.031 (BL C2-C7) + 0.02 (∆T4–T12)+ 0.63 (osteoporosis)−0.03 (anterior approach)−0.036 (frail)−0.032 (3 column osteotomy). This equation has a 77.8% accuracy of predicting DJK. A score ≥81 predicted DJK with an accuracy of 89.3%. The BL reference equation correlated with two year outcomes of Numeric Rating Scales of Back percentage (P=0.003), reoperation (P=0.04), and minimal clinically importance differences for 5-dimension EuroQol questionnaire (P=0.04).

Conclusions.

This study proposes a novel risk index of DJK development that focuses on potentially modifiable surgical factors as well as established patient-related and radiographic determinants. The reference model created demonstrated strong correlations with relevant two-year outcome measures, including axial pain-related symptoms, occurrence of related reoperations, and the achievement of minimal clinically importance differences for 5-dimension EuroQol questionnaire.
Metastasis of a Surgically Excised Melanoma In Situ
Authors: Anderson Jarett , Hamp Austin , Booms Alisha , Stover Kimberly Carlson
Published: July 2022

Melanoma in situ (MIS) is considered a noninvasive precursor to malignant melanoma and is defined as abnormal melanocytes that are confined to the epidermis without evidence of invasion through the basal membrane and into the deeper dermis. It is often referred to as Stage 0 melanoma.

MIS is thought to have no metastatic potential. However, several reports have shown that occult invasive disease may be found upon further testing of pathologically unequivocal MIS. In addition, several risk factors contribute to the upstaging of an MIS.

We present a case of a patient who was diagnosed with MIS who underwent excision of the primary lesion. Although the pathology report of the excision revealed negative margins, he was later found to have metastatic lesions to several lymph nodes, his parotid gland, and his brain. This resulted in extensive medical treatment that the patient did not originally anticipate.
Implementation of an Advanced Practice Registered Nurse–Led Clinic to Improve Follow-up Care for Post–Ischemic Stroke Patients
Authors: Mitchell Erin , Reynolds Staci S. , Mower-Wade Donna , Raser-Schramm Jonathan , Granger Bradi B.
Published: July 2022

BACKGROUND: Ischemic stroke continues to be a leading cause of serious disability within the United States, affecting 795 000 people annually. Approximately 12% to 21% of post–ischemic stroke patients will be readmitted to the hospital within 30 days of discharge. Studies suggest that implementation of a follow-up appointment within 7 to 14 days of discharge improves 30-day readmission rates; however, implementation of these guidelines is uncommon, and follow-up visits within the recommended window are not often achieved. The purpose of this project was to evaluate the impact of an advanced practice registered nurse (APRN)-led stroke clinic on follow-up care for post–ischemic stroke patients. The aims were to improve time to follow-up visit and reduce 30-day unplanned readmissions. METHODS: A pre/post intervention design was used to evaluate the impact of a process to access the APRN-led stroke clinic. The intervention included a scheduling process redesign, and subsequent APRN and scheduler education. RESULTS: The time to clinic follow-up preintervention averaged 116.9 days, which significantly reduced to 33.6 days post intervention, P = .0001. Unplanned readmissions within 30 days declined from 11.5% to 9.9%; however, it was not statistically significant, P = .149. Age was not statistically different between preintervention and postintervention groups, P = .092, and other demographics were similar between the groups. CONCLUSION: An APRN-led clinic can improve follow-up care and may reduce unplanned 30-day readmissions for post–ischemic stroke patients. Further work is needed to determine the impact of alternative approaches such as telehealth.
Defer no more: advances in the treatment and prevention of chronic hepatitis C virus infection in children
Authors: Honegger Jonathan R. , Gowda Charitha
Published: July 2022

Purpose of review

Direct-acting antiviral (DAA) regimens targeting hepatitis C virus (HCV) are now approved for young children. This review examines recent DAA experience in children, current treatment recommendations and challenges, and potential treatment-as-prevention strategies.

Recent findings

In 2021, the US FDA extended approval of two pan-genotypic DAA regimens, glecaprevir/pibrentasvir and sofosbuvir/velpatasvir, to children as young as age 3 years based on high success rates and reassuring safety profiles in registry trials. Similar performance has been replicated with real-world DAA use in thousands of adolescents and in limited reports of children with high-risk conditions, including cirrhosis, cancer, thalassemia and HIV-coinfection. Treatment without delay is now recommended in the USA for viremic children aged 3 years and up to prevent disease progression and future spread. To date, treatment expansion is limited by high rates of undiagnosed paediatric infection. Universal prenatal screening will aid identification of perinatally exposed newborns, but new strategies are needed to boost testing of exposed infants and at-risk adolescents. Postpartum treatment programmes can prevent subsequent vertical transmission but are hampered by low rates of linkage to care and treatment completion. These challenges may be avoided by DAA use in pregnancy, and this warrants continued study.

Paediatric HCV is now readily curable. Substantial clinical and public health effort is required to ensure widespread uptake of this therapeutic breakthrough.
Bacterial contamination of non-contact condensing lenses in National University of Malaysia Hospital isolated using BD BACTEC Peds Plus/F broth bottles versus conventional culture plates
Authors: Sivalingam Somasundranayaky a/p , Wong Kon Ken , Azura Sharifah , Syed Zulkifli Syed Zakaria , Wan Haslina Wan Abdul Halim , Bastion Mae-Lynn Catherine
Published: July 2022

Introduction. Non-contact condensing lenses (NCLL) are a requirement in ophthalmology examinations. To date, there have been no studies on the types of bacteria found on handheld lenses used to examine patients in an ophthalmology clinic.

Hypothesis. The BD BACTEC Peds Plus broth (BACTEC-PP) culture method can isolate more organisms as compared to conventional culture plates (CCP) from NCLL.

Aim. To evaluate the organism spectrum cultured from NCCL for fundus examination and to compare the results between BACTEC-PP and CCP. The isolation results were then related to the participant’s knowledge and hand hygiene practices (HHP).

Methodology. This is a comparative cross-sectional study involving consenting trainee ophthalmologists from a single centre, whose preferred NCCL was swabbed from January to December 2019. The respondents completed the adapted World Health Organization Hand Hygiene Knowledge and Perception Questionnaire, and their HHP were observed by Infective Control Unit nurses. Positive bacterial growth using both methods, in addition to hand hygiene practices, were compared.

Results. All samples had positive yields by at least one method. BACTEC-PP had a higher yield of 47 (90.4%) isolates compared to CCP with 37 (71.2%) isolates, P=0.041. CoNS sp (38.9 %) was the most common isolate with both methods, followed by

Bacillus

sp (25.3 %). At the same time, three fungi were detected with CCP only (3.2 %). There was a significant correlation in bacterial isolation with years of training, with fewer isolates among seniors in both BACTEC-PP (P=0.049) and CCP (P=0.034). There were no significant correlations between HHP and positive yields from either culture method.

Conclusions. NCCL used by trainee ophthalmologists are typically contaminated by at least one bacteria, with CoNS sp being the most commonly isolated. More positive cultures occurred in lenses from junior trainees. Contamination was not correlated with knowledge or HHP. BACTEC-PP has significantly higher yields than CCP for bacterial isolation from NCCL, but did not isolate any fungus.
Automated and manual segmentation of the hippocampus in human infants
Authors: Fel J. T. , Ellis C. T. , Turk-Browne N. B.
Published: July 2022

The hippocampus, critical for learning and memory, undergoes substantial changes early in life. Investigating the developmental trajectory of hippocampal structure and function requires an accurate method for segmenting this region from anatomical MRI scans. Although manual segmentation is regarded as the “gold standard” approach, it is laborious and subjective. This has fueled the pursuit of automated segmentation methods in adults. However, little is known about the reliability of these protocols in human infants, particularly when anatomical scan quality is low from increased head motion or shorter sequences that minimize head motion. During a task-based fMRI protocol, we collected quiet T1-weighted anatomical scans from 42 sessions with awake infants aged 4–23 months. We first had two expert tracers manually segment the hippocampus bilaterally and assess inter-rater reliability. We then attempted to predict these manual segmentations using four protocols: average adult template, average infant template, FreeSurfer software, and Automated Segmentation of Hippocampal Subfields (ASHS) software. ASHS generated the most reliable hippocampal segmentations in infants, exceeding manual inter-rater reliability of the experts. Automated methods can thus provide robust hippocampal segmentations of noisy T1-weighted infant scans, opening new possibilities for interrogating early hippocampal development.

Highlights

Inter-rater reliability of manual segmentation of infant hippocampus is moderate.

Template-based methods and FreeSurfer provide reasonably accurate segmentations.

ASHS produces highly accurate segmentations, exceeding manual inter-rater reliability.
Experimental infection of Mexican free-tailed bats (Tadarida brasiliensis) with SARS-CoV-2
Authors: Hall JS , Hofmeister E , Ip HS , Nashold SW , Leon AE , Malavé CM , Falendysz EA , Rocke TE , Carossino M , Balasuriya U , Knowles S
Published: July 2022

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus originated in wild bats from Asia, and as the resulting pandemic continues into its third year, concerns have been raised that the virus will expand its host range and infect North American wildlife species, including bats. Mexican free-tailed bats (Tadarida brasiliensis: TABR) live in large colonies in the southern United States, often in urban areas, and as such, could be exposed to the virus from infected humans. We experimentally challenged wild TABR with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of nine bats oronasally inoculated with SARS-CoV-2, five became infected and orally excreted moderate amounts of virus for up to 18 days post inoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while TABR are susceptible to SARS-CoV-2 infection, infection of wild populations of TABR would not likely cause mortality. However, the transmission of SARS-CoV-2 from TABR to or from humans, or to other animal species, is a distinct possibility requiring further investigation to better define.
GTPase-dependent cyclic flexibility transitions drive the two-component EEA1-Rab5 molecular motor
Authors: Singh Anupam , Soler Joan Antoni , Lauer Janelle , Grill Stephan W. , Jahnel Marcus , Zerial Marino , Thutupalli Shashi
Published: July 2022

The recognition of vesicles by their correct target compartment depends on the pairing of small GTPases with effector proteins (1–3). Whereas ATPases can cyclically convert the free energy of ATP hydrolysis into mechanical work, the function of small GTPases is predominantly associated with signal transduction processes, and their role in mechano-transduction is less established (4–6). However, binding of the GTPase Rab5 to the long coiled-coil tethering protein EEA1 on an early endosome induces a rigidity transition resulting in a large conformational change in EEA1 from a rigid and extended to a flexible and collapsed state. This entropic collapse of EEA1 gives rise to an effective force that can pull tethered membranes closer (7). It currently remains unclear if EEA1 can return from the collapsed to the extended conformation without the aid of chaperones. Here, we use fluorescence correlation spectroscopy to reveal that EEA1 in bulk solution can undergo multiple flexibility transition cycles that are associated with the binding and release of Rab5(GTP) and Rab5(GDP). Using semi-flexible polymer theory we provide evidence that the cyclic transitioning of Rab5-EEA1 between extended and collapsed conformations is driven by the energetics of Rab5 binding/unbinding and GTP hydrolysis. Cyclic flexibility transitions represent a complete mechanical work cycle that is able to perform up to 20 kBT of mechanical work per cycle, against an opposing force. Hence, Rab5 and EEA1 constitute a two-component molecular motor driven by the chemical energy derived from GTP hydrolysis by Rab5. We conclude that coiled-coil tethering proteins and their small GTPase partners can have active mechanical roles in membrane trafficking.
The mediating role of work–family conflict on role overload and job stress linkage
Authors: Dodanwala Tharindu C. , Santoso Djoen San , Shrestha Pooja
Published: July 2022

Purpose

The present study first explored the different dimensions of work–family conflict and job stress. It then evaluated the mediating role of time and strain-based work–family conflict on the relationship between role overload and psychological stress and role overload and physiological stress.

Design/methodology/approach

The study utilized a quantitative data collection approach through a questionnaire design. With the aid of the questionnaire, 308 samples were collected from the project-level staff of ten construction organizations in Sri Lanka. The collected data were analyzed using a structural equation modeling approach to address the research hypotheses.

Findings

Results supported the mediating role of work–family conflict on the relationship between role overload and job stress. Specifically, the time and strain-based work–family conflict combined partially mediated the effect of role overload on psychological stress. While strain-based work–family conflict fully mediated the effect of role overload on physiological stress. Hence, the organizations that seek employee well-being should focus on developing a conducive working environment with a focus on a reasonable workload for everyone. Besides, the management should give special consideration to working hours as it affects both the employees' stress levels and family life.

Originality/value

This study added the mediating role of time and strain-based work–family conflict to the previous empirical research on the relationship between role overload and job stress dimensions. Besides, this study discusses the different dimensions of work–family conflict and job stress, which is a less explored area in the construction literature.
Entrepreneurial orientation in family firms: the effects of long-term orientation
Authors: Seyed Kalali Nader
Published: July 2022

Purpose

This paper aims to shed light on the relationship between long-term orientation (LTO) and the dimensions of entrepreneurial orientation (EO) in family firms while adopting a stewardship perspective.

Design/methodology/approach

A survey of the top managers of family firms in Iran's science and technology parks was conducted, and partial least squares structural equation modeling (PLS-SEM) was used to analyze the collected data.

Findings

The research results showed that LTO has a positive effect on innovativeness and proactiveness and a negative effect on riskiness. Therefore, family firms' LTO pays off by enhancing their EO.

Practical implications

In today's competitive world, EO is gradually becoming an inevitable necessity in many industries. Executives who want their firms to have a high level of performance should pay special attention to entrepreneurial behaviors. The present research informs the family firms' managers and practitioners to be long-term oriented to embrace more innovativeness and proactiveness, and less riskiness.

Originality/value

So far, the relationship between the LTO and entrepreneurial characteristics of family firms has remained ambiguous; this research is one of the first studies investigating this relationship.
Debt dynamic, debt dispersion and corporate governance
Authors: Tut Daniel
Published: July 2022

Purpose

This paper addresses the following questions: Why do some firms employ multiple debt types? What explains debt heterogeneity? Is the choice of the source of debt a function of corporate governance?

Design/methodology/approach

The author's paper is empirical and uses multiple regression analysis.

Findings

Firms under weak corporate governance have a higher propensity to use multiple debt types and have a dispersed debt structure. Contrastingly, firms that are well-managed tend to concentrate debt and borrow predominantly from a few creditors. The author also found that while bank debt is negatively associated with debt concentration, market debt is positively associated with debt concentration.

Research limitations/implications

Firms under weak corporate governance have a higher propensity to use multiple debt types and have a dispersed debt structure. Well-managed firms tend to concentrate debt and borrow predominantly from a few creditors. Bank debt is negatively associated with debt concentration and market debt is positively associated with debt concentration.

Practical implications

Policymakers and practitioners need to account not only for changes in the firm’s total debt level but also for changes within the firm’s debt composition. Understanding a manager’s choice of debt structure can incentivize creditors to effectively monitor and use debt concentration as a form of commitment device that transfers some control rights from the manager to creditors.

Originality/value

While a vast body of corporate finance literature examines the conflict between shareholders and management, there is little empirical work on the conflict between creditors and management. In this paper, the author examines how managerial entrenchment affects debt structure. The results provide a comprehensive picture of how corporate governance influences debt choice(s).
An unintended consequence of flexible work arrangements (FWAs) – the role of peer resentment on turnover intentions in public accounting
Authors: Calhoun Magan , McCarthy Vikkie
Published: July 2022

Purpose

As public accounting firms continue to leverage technology to retain and recruit employees, options for flexible work arrangements (FWAs) expand. However, offering FWAs may not be enough. This study aims to investigate the influence of FWAs on perceived peer resentment and turnover intentions in public accounting. A mediation effect of perceived peer resentment between types of FWAs used and turnover intentions is explored.

Design/methodology/approach

The analysis is based on survey data collected from a total of 212 respondents currently or recently working in public accounting. Hypotheses have been tested using ordinary least squares regression and the PROCESS macro in SPSS.

Findings

Study findings indicate that the number of types of FWAs used and perceived peer resentment positively influence turnover intentions.

Research limitations/implications

This study explores developments in retaining and recruiting employees when public accounting firms implement FWAs. In particular, it discusses a new potential unintended consequence, perceived peer resentment toward employees using FWAs.

Practical implications

Public accounting firms that seek to retain and recruit top talent must go beyond offering various forms of FWAs if they intend to reduce turnover in their firms. This study provides evidence that peer relationships play a greater role in the turnover intention process when FWAs are used.

Originality/value

This study is among a few which examine the variable perceived peer resentment in relationship to FWAs and its influence on turnover in public accounting firms.
Financial services and firm performance, are there any differences by size? Worldwide evidence using firm-level data
Authors: Elouaourti Zakaria , Ezzahid Elhadj
Published: July 2022

Purpose

Do financial services needs depend on the firm size? To highlight the impact of different categories of financial services on firm performance, we establish a correspondence between financial services and firms' performance classified according to their size, controlling with the determinants of firm performance and the obstacles that hinder the development of each category of firm.

Design/methodology/approach

We have mobilized microeconomic data on 78,629 firms stratified by size and covering 135 countries, extracted from the Enterprise Surveys database. A two-stage least squares (2SLS) regression analysis with instrumental variable modeling is used.

Findings

Our empirical results show that a firm's financing behavior differs according to its size. For micro and small firms, the availability of internal financing has a positive impact on their performance. For medium-size firms, the use of debt stimulates firm performance. For large firms, the positive effect of debt diminishes as the level of debt increases, which leads this category of firms to increase their capital. We complemented our study by exploring the issue of whether barriers to firm performance differ by size. Our results bring a support to the idea that medium-size firms suffer more than micro, small, and large firms. The size of this category of firms does not allow them to operate in the informal sector as micro and small firms do, and does not allow them to influence political authorities to operate in their favor as large firms do.

Originality/value

Previous studies have focused on investigating the effects of access to finance and/or financing constraints on firm's performance, neglecting the issue of identifying which financial services have the most impact on firm performance depending on firms' size. This study fills the gap in the literature in two main ways. First, we identify the financial services that have the most impact on firm performance using firm-level data covering 78,629 firms by size (micro, small, medium, and large). Second, we investigate the different barriers to firm performance by size.
Linking knowledge search to knowledge creation: the intermediate role of knowledge complexity
Authors: Hou Tianyu , Li Julie Juan , Lin Jun
Published: July 2022

Purpose

Knowledge search is considered a broad concept and semi-intentional behavior. The path and boundary conditions through which search strategies affect intra-organizational knowledge creation remain elusive. Drawing on recombinant search theory and knowledge-based view, the authors seek to identify knowledge complexity as an important intermediate variable between knowledge search and innovation performance, such as research and development (R&D) output and R&D output quality. A second goal of this study is to examine the moderating roles of government support and technological turbulence.

Design/methodology/approach

The authors employed a longitudinal panel of 609 global pharmaceutical firms and obtained the firms' patent records from 1980 to 2015 for the analysis. The authors used generalized estimating equations (GEE) to evaluate the models and tested the consistency via panel fixed-effects estimations.

Findings

The authors' findings show that organizational routine-guided search has a negative effect on knowledge complexity, while routine-changing search exerts a positive impact on knowledge complexity. Governmental support and technological turbulence moderate these relationships. Notably, knowledge complexity has an inverted U-shaped relationship with innovation performance.

Research limitations/implications

The authors' research context, the pharmaceutical industry, may constrain the generalizability of our findings. In addition, potential types of routine-guided and routine-changing search behaviors were not considered.

Practical implications

Despite these limitations, this study offers important implications. First, knowledge complexity transmits the effects of knowledge search on innovation performance. Practitioners should balance routine-guided and routine-changing search processes to build and manage complex knowledge. Second, a moderate level of knowledge complexity is the key to good R&D output and R&D output quality.

Originality/value

The study identifies knowledge complexity as one important intermediate variable between knowledge search behaviors and intra-organizational knowledge creation.