bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtual reality and augmented reality applications and their effect on tourist engagement: a hybrid review
Authors: Omran Wajdy , Ramos Ricardo F. , Casais Beatriz
Published: October 2023

Purpose

This study consolidates insights on the role of virtual reality (VR) and augmented reality (AR) in tourism engagement (TE). In addition, it suggests new directions for research in tourism and hospitality.

Design/methodology/approach

A hybrid integrative review was used with bibliometric and theory-context-characteristics-method framework analyses of 236 peer-reviewed journal articles.

Findings

Computer science journals dominate TE in VR/AR research. Emotional and immersive attributes of VR/AR sustain TE. Exploring cultural theories can enrich TE perspectives in the context of VR/AR. This study offers fruitful directions by exploring virtual technology’s role in sustaining cultural heritage and studying TE intentions and perceptions on VR/AR tourism mobile applications.

Originality/value

To the best of the authors’ knowledge, this is the first study that uncovers the structure and intellectual rationale of existent research.
Investigating how consumer-perceived value and store image influence brand loyalty in emerging markets
Authors: Islam Shahidul , Zahin Mashiat , Rahim Shahida Binte
Published: October 2023

Purpose

This study examines the impact of consumer-perceived value (CPV) dimensions such as product quality, price fairness, brand prestige and brand positioning on brand attitude and loyalty for electronic home appliance brands in an emerging market. It also explores the moderating effect of perceived store image on the relationship between brand attitude and loyalty.

Design/methodology/approach

This study proposes an integrated model based on consumption values and the value-attitude-behavior (V-A-B) framework. Survey data from 209 Bangladeshi consumers of electronic home appliances were used to test the model. Covariance-based structural equation modeling (CB-SEM) and PROCESS macro were employed to test the hypotheses.

Findings

This research underscores the importance of CPV dimensions, such as product quality, price fairness, brand prestige and positioning, in predicting brand loyalty through brand attitude. Store image moderates the link between brand attitude and loyalty, with a stronger relationship when store image is high and a weaker relationship when it is low.

Originality/value

This study broadens marketing and consumption value theory by investigating brand prestige and positioning in the V-A-B framework in the emerging market. This is the first study to use perceived store image to moderate the relationship between brand attitude and loyalty.
The double pandemic: diversity, equity and inclusion at Yale University School of Medicine in the era of COVID-19
Authors: Al Arkoubi Khadija , Mendez-Fernandez Yanice , Gionet Paige , Canino Teresa
Published: October 2023

Research methodology

This case was based on both primary and secondary data. In-depth semidirected interviews were conducted in 2021–2022 after receiving the institutional research board approval. The interviews took an approximate time ranging from 90 to 120 min. They were recorded and transcribed. A thematic analysis was undertaken to identify the most relevant themes for the case. The secondary sources used included various websites, scholarly and trade journals, as well as specific databases, such as Statista.

Case overview/synopsis

The case exposes students in multiple disciplines to the challenges created by the COVID-19 crisis at Yale School of Medicine (YSM). It describes its remarkable effects on organizational and community members as they struggled to reimagine more inclusive and supportive spaces. As one of the most severe crises humanity has ever witnessed, COVID-19 exacerbated the existing struggles of the underrepresented communities, creating a double pandemic. It has also amplified inequities among marginalized groups including black, indigenous and people of color; women; immigrants; lesbian, gay, bisexual, transgender, queer/questioning; people with different abilities; working parents; single parents; religious minorities; and people with low income. When COVID-19 hit in 2020, Yale University School of Medicine (YSM), like other pioneering schools in the field of health care, doubled their efforts to face both the public health crisis and the substantial social turmoil (racial tensions after the death of George Floyd, food insecurity, vaccine resistance, social inequalities, etc.). Professor Marietta Vazquez, MD, who was the first Latina to be named Associate Dean for Medical Students Diversity at YSM, launched with Dr Latimore (Chief Diversity Officer) and her other colleagues many strategic initiatives aiming at improving the diversity, equity and inclusion of organizational and community members.

The case is an invitation to graduate students and students in executive education programs to reflect on the grand challenges leaders faced at YSM as well as in other institutions across the nation and the globe. It is also a call to reimagine ways leaders can accelerate the pace of change in their organizational ecosystems.

Complexity academic level

This case was written for use in graduate-level courses, including executive education dealing with Diversity, Equity, Inclusion and Belonging, Leadership and Change, Health-Care Equity/Policy, Health Sciences, Human Resource Management, Organizational Behavior, Crisis Management, Sustainability, Business and Society, Social Issues in Management, Strategy, etc. Faculty members can easily adapt the case to fit the content of the course they teach, the students’ context as well as the specific learning outcomes to be achieved.
Attenuating free‐surface multiples and ghost reflection from seismic data using a trace‐by‐trace convolutional neural network approach
Authors: Kiraz Mert S. R. , Snieder Roel , Sheiman Jon
Published: October 2023

The presence of the air–water interface (or free‐surface) creates two major problems in marine seismic data for conventional seismic processing and imaging: free‐surface multiples and ghost reflections. The attenuation of free‐surface multiples remains one of the most challenging noise attenuation problems in seismic data processing. Current solutions suffer from the removal of the primary events along with the multiple events especially when the primary and multiple events overlap (e.g., adaptive subtraction). The effective attenuation of ghost reflections (or deghosting) requires acquisition‐ and/or processing‐related solutions which generally address the source‐side and receiver‐side ghosts separately. Additionally, an essential requirement for a successful implementation of free‐surface multiple attenuation and seismic dehosting is the requirement of dense seismic data acquisition parameters which is not realistic for two‐dimensional and/or three‐dimensional marine cases. We present a convolutional neural network approach for free‐surface multiple attenuation and seismic deghosting. Unlike the existing solutions, our approach operates on a single trace at a time, and neither relies on the dense acquisition parameters nor requires a subtraction process to eliminate free‐surface multiples, and it removes both the source ghost and receiver ghost simultaneously. We train a network using subsets of the Marmousi and Pluto velocity models and make predictions using subsets of the Sigsbee velocity model. We show that the convolutional neural network predictions give a correlation coefficient of 0.97 on average with the numerically modeled data for the synthetic examples. We illustrate the efficacy of our convolutional neural network–based technique using the Mobil AVO Viking Graben field data set. The application of our algorithm demonstrates that our convolutional neural network–based approach removes different orders of free‐surface multiples (e.g., first and second orders) and recovers the low‐frequency content of the seismic data (which is essential for, for instance, full‐waveform inversion applications and broadband processing) by successfully removing the ghost reflections while preserving and increasing the continuity of the primary reflection.
Financing community partnerships for health equity: Findings and insights from cross‐sector professionals
Authors: Hoornbeek John , Chiyaka Edward T. , Lanese Bethany , Vreeland Amy , Filla Joshua
Published: October 2023

Objective

To enhance understanding of financial alignment challenges facing cross‐sector partnerships (CSPs) pursuing health equity and offer insights to guide research and practice.

Data Sources and Study Setting

We collected data through surveys and interviews with cross‐sector professionals in 16 states, 2020–2021.

Study Design

We surveyed 51 CSP leaders and received 26 responses. Following administration of the surveys to CSP leaders, we also conducted interviews with cross‐sector professionals. The data are analyzed descriptively, comparatively, and qualitatively using thematic analysis.

Data Collection/Extraction Methods

For quantitative survey data, we compare partnership responses, differentiating perceived levels of alignment among partnerships certified by the Pathways Community HUB Institute (PCHI), partnerships interested in certification, and partnerships without connection to the PCHI® Model of care coordination. For interviews, we engaged CSP professionals and those who fund their work. Two research team members took notes for interviews, which were combined and made available for review by those interviewed. Data were analyzed independently by two team members who met to integrate, identify, and finalize thematic findings.

Principal Findings

Our work supports previous findings that financing is a challenge for CSPs, while also suggesting that PCHI‐certified partnerships may perceive greater progress in financial alignment than others. We identify four major financial barriers: limited and competitive funding; state health service delivery structures; cultural and practice divides across healthcare, social service, and public health sectors; and needs for further evidence of cross‐sector service impacts on client health and costs. We also offer a continuum of measures of financial sustainability progress and identify key issues relating to financial incentivization/accountability.

Conclusion

Findings suggest a need for public policy reviews and improvements to aid CSPs in addressing financial alignment challenges. We also offer a measurement framework and ideas to guide research and practice on financial alignment, based on empirical data.
Outcomes and poor prognostic factors in endovascular thrombectomy for octo‐ and nonagenarians with large vessel occlusion: A real‐world experience
Authors: Yu Stephanie Wing Yin , Zhuang James Tin‐Fong , Chu Yin Lun Edward , Teo Kay‐Cheong , Lau Kui Kai , Tsang Anderson Chun‐On , Lui Wai‐Man
Published: October 2023

Endovascular thrombectomy (EVT) is the preferred treatment for eligible patients with acute large vessel occlusions (LVOs). However, its role in very elderly patients remains uncertain. This study retrospectively analysed EVT outcomes, including successful reperfusion, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 h after EVT, inpatient haemorrhagic transformation and favourable functional outcomes and mortality at 90 days after EVT in patients aged over 80 years. The primary outcome of the study was risk factors significantly associated with poorer functional outcomes at 90 days after EVT. The secondary outcomes were risk factors associated with higher NIHSS scores at 24 h after EVT and higher mortality rates at 90 days after EVT. Among the 73 octo‐ and nonagenarians, successful reperfusion was achieved in 86.3%, and up to 35.6% maintained functional independence at 90 days. Poorer outcomes were associated with internal carotid artery occlusion; risk factors such as hypertension, diabetes mellitus and atrial fibrillation; higher admission NIHSS score; longer time between symptom onset and successful reperfusion and unsuccessful reperfusion. EVT is both safe and effective in our elderly population, with over one‐third of very elderly patients achieving satisfactory functional outcomes after EVT. Therefore, age alone should not be the sole criterion for excluding very elderly LVO patients from EVT. Instead, each patient should undergo individual assessment based on their premorbid condition, clinical presentation and LVO characteristics before making a treatment decision.
Hydra: Lessons from the world's largest darknet market
Authors: Goonetilleke Priyanka , Knorre Alex , Kuriksha Artem
Published: October 2023

Research Summary

We present a comprehensive description of Hydra, the largest darknet marketplace in the world until its shutdown in April 2022. We document the main features of Hydra such as dead‐drop delivery, feedback and reputation system, escrow, and dispute resolution. Using data scraped from the platform, we quantitatively examine the scale and the structure of the marketplace. We find that it has been highly competitive, geographically covering at least 69% of the Russian population and trading a wide variety of drugs, while also allowing the wholesale trade of drugs and precursors. The dead‐drop delivery system used on Hydra was expensive, as the courier costs comprised a substantial proportion of the sale price of drugs on Hydra. We contribute to the research on drug cryptomarkets by studying an unprecedentedly large non‐Western marketplace that existed substantially longer than any other known darknet market.

Policy Implications

The phenomenon of Hydra shows that shut‐down policies applied to darknet marketplaces have a large effect and implicitly shape the whole drug market. Without these policies, a pervasive digitalization of the drug trade can occur. The major cost of allowing marketplaces to grow is the probable increase in the consumption of illegal drugs due to convenience for consumers and facilitated cooperation between suppliers. This cost must be weighed against the potential benefits, including a higher quality of drugs, a decrease in potential violence, and the incentives for a large marketplace to self‐regulate. The case of Hydra also suggests the relevance of financial regulation to limit the growth of darknet marketplaces.
Ambulance and helicopter response time. Association with patient outcome and illness severity: Protocol of a systematic literature review and meta‐analysis
Authors: Hansen Peter Martin , Nielsen Martine Siw , Rehn Marius , Lassen Annmarie Touborg , Mikkelsen Søren , Perner Anders , Brøchner Anne Craveiro
Published: October 2023

Background

Response time for emergency medical service units is a key performance indicator. Studies have shown reduced response time association with improved outcome for specific critical conditions. To achieve short response time, emergency vehicles utilize lights and sirens, and crews are allowed to be non‐compliant with traffic rules, posing a risk for accident.

The purpose of the systematic review and meta‐analysis is to provide an overview of the current body of evidence regarding the association, if any, between ambulance and helicopter response time and major complications and mortality in patients conveyed by ambulance and/or helicopter. Our secondary aim will be to enhance knowledge in the field of criteria‐based dispatch to provide decision makers with evidence to optimize dispatch of limited resources.

Research Questions

What is the association between overall emergency medical services unit response time and patient outcomes, major complications, and time‐critical conditions?

What is the internal and external validity of the included literature?

Methods

We plan the systematic review and meta‐analysis to be in accordance with the Cochrane Handbook and Joanna Briggs Institute Manual for Systematic Reviews. The methodology will include formulating the review questions using a Population, Exposure, and Outcome framework. Every study design is eligible, including qualitative, quantitative, and mixed‐methods designs. We will include all articles in English, Scandinavian, German, French and Portuguese in this systematic review.

Results

We will publish results from the systematic review and meta‐analysis in a peer‐reviewed journal and we will present the results at scientific conferences and meetings. Results will also be available at www.ahrtemis.dk.

Conclusion

We will base our conclusions on the findings of the review and meta‐analysis.
Household loan portfolios and financial characteristics of Korean banks
Authors: Seo Ji‐Yong
Published: October 2023

This study contributes to understanding the supply mechanism of household loan portfolios in Korea, where the ratio of household debt to GDP is high. This study conducted an empirical analysis of how banks' financial characteristics including capital adequacy, financial soundness, and profitability affect banks' supply of variable‐rate household loans that are sensitive to increases in the central bank's base interest rate and have higher possibility of loan default, considering time lag in terms of banks' risk‐taking behaviour. The main results suggest that the proportion and change of variable‐rate loans are significantly affected by the level and change of financial characteristics. In particular, a high level of capital adequacy enabled banks to supply risky loans by increasing their risk tolerance.
Opportunistic prostate‐specific antigen testing in Norwegian men: a public health challenge
Authors: Albertsen Peter C. , Bjerner Lars Johan , Pasovic Lara , Müller Stig , Fosså Sophie , Carlsson Sigrid V. , Oldenburg Jan
Published: October 2023

Objective

To describe age‐specific prostate‐specific antigen (PSA) distributions and resulting prostate cancer diagnoses that arise from population‐wide opportunistic PSA testing.

Patients and Methods

Over 8 million PSA tests were performed on >1.4 million Norwegian men from 2000 to 2020. During this period 43 486 men were diagnosed with localised prostate cancer. Most of the PSA testing reflected opportunistic testing. Age‐specific PSA value distributions were constructed for men aged 45–75 years with and without prostate cancer.

Results

The distributions of PSA values in men with and without prostate cancer widened with age and overlapped extensively from 3 to 7 ng/mL. Localised prostate cancer diagnoses increased 10‐fold from the age of 45 to 75 years. PSA testing identified intermediate‐ or high‐grade cancers in 21% (95% confidence interval [CI] 19–23%) of men aged 50–54 years and 42% (95% CI 41–43%) of men aged 70–74 years. Grade group (GG)1, GG2, GG3 and ≥GG4 constituted 49%, 31%, 10% and 10% of cancers identified at age 50–54 years and 26%, 26%, 18%, and 30% of cancers identified at age 70–74 years.

Conclusion

Opportunistic PSA testing increases with ageing and often generates values that cannot discriminate benign prostate enlargement from prostate cancer. A clinical cascade using additional imaging or serum tests is necessary to avoid negative biopsies and the overdiagnosis of indolent disease. The declining specificity of PSA testing with ageing poses a significant public health challenge especially among older men aged ≥70 years.
Unintended consequences: Alcohol screening at urban Aboriginal Community Controlled Health Services was suppressed during COVID‐19 lockdowns
Authors: Conigrave James H. , Devine Emma K. , Lee K. S. Kylie , Dobbins Timothy , Vnuk Julia , Hayman Noel , Conigrave Katherine
Published: October 2023

Introduction

Regular screening for risky drinking is important to improve the health of Aboriginal and Torres Strait Islander Australians. We explored whether the rate of screening for risky drinking using the Alcohol Use Disorders Identification Test—Consumption (AUDIT‐C) questions was disrupted at Aboriginal Community Controlled Health Services (ACCHS) during state‐wide and territory‐wide COVID‐19 lockdowns in 2020.

Methods

Retrospective analysis of screening data from 22 ACCHSs located in New South Wales, the Northern Territory, Queensland, South Australia, Victoria and Western Australia. These services provide holistic and culturally appropriate primary care. A multi‐level Poisson regression, including AR(1) autocorrelation, was used to predict counts of AUDIT‐C screening at ACCHSs.

Results

AUDIT‐C screening was suppressed during state‐wide and territory‐wide lockdowns in 2020 (incident rate ratio [IRR] 0.42 [0.29, 0.61]). The effect of lockdowns differed by service remoteness. While there was a substantial reduction in AUDIT‐C screening for urban and inner regional services (IRR 0.25 [95% confidence interval (CI) 0.15, 0.42]), there was not a statistically significant change in screening at outer regional and remote (IRR 0.60 [95% CI 0.33, 1.09]) or very remote services (IRR 0.67 [95% CI 0.40, 1.11]).

Discussion and Conclusions

The COVID‐19 lockdowns in Australia likely suppressed rates of screening for risky drinking in urban and inner regional regions. As harm from alcohol consumption may have increased during lockdowns, policymakers should consider implementing measures to enable screening for risky drinking to continue during future lockdowns.
Introducing a novel educational training programme in dental implantology for pregraduate dental students
Authors: Fischer Theresa , Fehlhofer Jakob , Kesting Marco Rainer , Matta Ragai Edward , Buchbender Mayte
Published: October 2023

Introduction

This study aimed to determine whether implant surgery procedures can be implemented in the dental curriculum by designing novel courses for students. Additionally, this study assesses the perception of these courses and how they can be established in the future.

Materials and Methods

Students from the third to fifth years participated in a programme consisting of 4 modules according to their academic year. The modules taught theoretical and practical content as well as clinical references. After participating, the students completed two questionnaires with research questions (RQ1 = evaluation of the relevance and effects; RQ2 = impact of modules 3 and 4) to evaluate the programme. The questionnaires consisted of 52 statements, each rated on a 6‐point scale (1 ‘totally disagree’ to 6 ‘totally agree’). Cronbach's alpha analysis was used, and median values, interquartile ranges and Pearson correlations (p‐value) were statistically calculated.

Results

In total, 94 students completed the questionnaires. Cronbach's alpha exceeded 0.7 for all constructs except for one (skills training). The highest evaluated median was 6, and the lowest was 4.75. Pearson correlations were significant (<0.05) for perceived importance/lectures, perceived importance/tutor performance, lectures/skills training, skills training/tutor performance and tutor performance/lectures. Seventeen analysed free comments expressed strong interest in implantology courses for the curriculum. 88% of the students wished for more practical exercises in dental implantology during the curriculum or suggested expanding the programme in the future.

Conclusion

The programme was highly accepted among dental students. The students wished for more practice in the future to perform supervised procedures on patients.
A cascaded deep learning framework for iris centre localization in facial image
Authors: Ahmad Naseem , Muhammad Ghulam , Yadav Kuldeep Singh , Laskar Rabul Hussain , Hossain Ashraf , Ali Zulfiqar
Published: October 2023

Accurate iris centre localization is crucial in many computer vision and facial biometric applications such as gaze estimation, human–computer interaction, iris recognition, and liveness detection. However, it is challenging in an uncontrolled environment due to variations like pose, scale, rotation, specular reflection, and image quality. Therefore, a cascaded deep learning framework for iris centre localization in facial images is proposed that is robust to the abovementioned variations. The proposed approach consists of (i) YOLOv3 for eye detection, (ii) UNet for iris segmentation, and (iii) statistical modelling for iris centre localization. The eyes are first detected using the YOLOv3, and subsequently, iris segmentation is performed within the detected eyes using the UNet. Following iris segmentation, statistical modelling is employed to enhance the localization accuracy of the iris centre. Experiments were performed on benchmark databases, resulting in a standardized error measure SED of 3.405 pixels for BioID and 3.259 pixels for GI4E databases. In addition, the robustness of the proposed eye detection model was further evaluated on the Yale B for illumination variations and the CAS‐PEAL for pose variations.
Is corporate finance research in decline?1
Authors: Denis David J.
Published: October 2023

There has been a secular decline in published research on corporate finance topics over the past decade or so. While this raises questions about the vitality of the field going forward, I argue that a number of recent developments represent important new directions for research in corporate finance. These developments have begun to have an impact on scholarly activity and I expect this to continue in the near future.
Diversity in patient and public involvement in healthcare research and education—Realising the potential
Authors: Hatch Sarah , Fitzgibbon Jim , Tonks Amanda Jayne , Forty Liz
Published: October 2023

Background

Patient and public involvement (PPI) is an increasing priority in health‐related research and education. Attracting and supporting people from different demographic groups to give up their time and get involved is important to help ensure that all parts of society are empowered, represented and their voices heard in decisions that may affect their health and quality of life.

Objectives

(1) To determine if a demographically diverse cross‐section of society would be interested in contributing to healthcare research and education. (2) To understand factors that can act as barriers and enablers to effective and diverse PPI.

Method

PPI survey data was collected via engagement events, with the aim of scoping interest in PPI from a diverse public. A Focus Group study involving members of the public, academic and professional service staff, was then conducted to gain a deeper understanding around the barriers and enablers of diversity within PPI.

Results

71% of a diverse rich public indicated they would like to get involved in healthcare research and teaching. 76% of survey respondents indicated that they would be happy to share a personal or family experience of healthcare. The two biggest factors impacting on our cohort getting involved are’ availability of time’ and ‘being aware of PPI opportunities’. These factors may disproportionally affect specific groups. Shared and individual PPI enablers and barriers were identified across all stakeholder groups within the Focus Group Study, as well as generic and novel factors that would impact on an institutions’ ability to improve PPI diversity.

Conclusion

These data points confirm a demographically diverse public's appetite to get involved in academic health research and teaching. This needs to be recognised and harnessed to ensure public contributor networks are representative of society. Equality Impact Assessments should be undertaken in relation to all PPI opportunities. There is a need to recognise the investment of time and resources required to build mutually beneficial relationships with diverse communities as well as the development of inclusive ‘fit for purpose’ PPI infrastructures to support the uptake of diverse PPI contributors.

Public Contribution

This study involved members of the public responding to a short survey. Public contributors made up one of the three focus groups. The School of Medicine lead public contributor was also involved in the preparation of this manuscript.
The effects of land use change on ant communities in New England
Authors: Curry Amelia K. L. , Nelsen Joseph A. , Stevens Dale R. , Mathis Kaitlyn A.
Published: October 2023

Urbanisation and agricultural expansion are two of the most prevalent and intense forms of land use change worldwide and can have dramatic consequences on biodiversity and biotic community structure.

Ants are extremely widespread, ecologically diverse and small ectotherms that are sensitive to changes from a wide range of environmental factors. Therefore, ants make an ideal study organism to examine the effects of anthropogenic land use change on biotic communities.

In this study, we examined differences in ant species richness and community composition between urban parks, farms and forest fragments, and related these differences to environmental factors that vary among each of these three habitat types.

We sampled 46 sites across Worcester County and found farms have significantly lower ant species richness than parks, and all habitat types had different ant community compositions. We also identified higher plant species richness is associated with higher ant species richness, and both plant species richness and air temperature are associated with differences in community composition.

Our findings support that habitats affected by human land use will host different assemblages of ant species compared to those found in nearby natural habitats, as seen in our New England forest fragments.
Genomic alterations in blast phase of BCR::ABL1‐negative myeloproliferative neoplasms
Authors: Chen Dong , Weinberg Olga K.
Published: October 2023

The blast phase of BCR::ABL1‐negative myeloproliferative neoplasm (MPN‐BP) represents the final stage of the disease, which is complicated by complex genomic alterations. These alterations result from sequence changes in genetic material (DNA, RNA) and can lead to either a gain or loss of function of encoded proteins, such as adaptor proteins, enzymes, components of spliceosomes, cell cycle checkpoints regulators, transcription factors, or proteins in cell signaling pathways. Interference at various levels, including transcription, translation, and post‐translational modification (such as methylation, dephosphorylation, or acetylation), can contribute to these alterations. Mutated genes such as ASXL1, EZH2, IDH1, IDH2, TET2, SRSF2, U2AF1, TP53, NRAS, KRAS, PTPN11, SH2B3/LNK, and RUNX1 play active roles at different stages of genetic material expression, modification, and protein function manipulation in MPNs. These mutations are also correlated with, and can contribute to, the progression of MPN‐BP. In this review, we summarize their common mutational profiles, functions, and associations with progression of MPN‐BP.
Newborns' perception of approach and withdrawal from biological movement: A closeness story
Authors: Roberti Elisa , Addabbo Margaret , Colombo Lorenzo , Porro Matteo , Turati Chiara
Published: October 2023

Since birth, infants discriminate the biological motion (BM) revealed by point‐light displays (PLDs). To date, no studies have explored whether newborns differentiate BM that approaches rather than withdraws from them. Yet, approach and withdrawal are two fundamental motivations in the socio‐emotional world, key to developing empathy and prosocial behavior. Through a looking‐behavior paradigm, we demonstrated that a few hours after birth, a human figure approaching attracted more visual attention than a human figure receding, showing that newborns are attuned to PLDs of others moving toward rather than walking away from them. Further, a withdrawing body appears to be less attractive than withdrawing scrambled points. Altogether, these observations support the existence of an early predisposition toward social closeness that might have its roots in an evolutionary perspective.
What influenced frontline nurses’ mental health during the early phase of the COVID‐19 pandemic
Authors: Choi Yun‐Jung , Um Youn‐Joo , Cho Dong‐Hee
Published: October 2023

Aim

This cross‐sectional study aimed to investigate the factors that affected the mental health of Korean nurses caring for coronavirus disease 2019 (COVID‐19) patients, causing posttraumatic stress disorder, depression, anxiety, and sleep disorders.

Background

Infectious disease outbreaks like COVID‐19 affect the mental health not only of those who contract the disease but also of nurses caring for affected patients.

Introduction

To address health issues effectively, it is essential to comprehend how to prevent them. Therefore, it is necessary to scrutinize the origins of COVID‐19–related health concerns and devise measures to prevent potential problems.

Method

We used an online survey to collect data from 136 nurses caring for COVID‐19 patients during the initial stage of the pandemic. The data were analyzed using the one‐way analysis of variance and a simple logistic regression.

Results

The findings confirmed a high prevalence of posttraumatic stress disorder among nurses, with symptoms of depression, anxiety, and sleep problems.

Discussion

Our research has shown that it is important not to exacerbate the difficulties that nurses face after their activities. Therefore, it proposes for creating environmental structures that mitigate predictable challenges such as workload from various tasks, sleep disturbances, and hopelessness, rather than focusing on personal vulnerabilities.

Conclusion

Timely attention to influencing factors can reduce the risk to nurses' mental health, so we need to plan preventive measures that reflect the influencing factors to prepare for future pandemics.

Implications for nursing and health policy

Continuous monitoring of the mental health status of nurses responding to a global health crisis and the development of appropriate psychological support programs and policies for creating a conducive work environment are necessary.
Increasing cytostatic effects of ricin A chain and Staphylococcus aureus enterotoxin A through in vitro hydrophobization with fatty acid residues
Authors: Alakhov V Yu , Kabanov AV , Batrakova EV , Koromyslova IA , Levashov AV , Severin ES
Published: October 2023

In order to impart an ability for receptor‐independent transmembrane transfer to water‐soluble proteins, it has been suggested that they be hydrophobized by lipid groups (fatty acids, etc.). To this end, systems of reversed micelles of surfactants in organic solvents were used as reaction media for protein modification. It was shown that after introduction of a hydrophobic anchor (stearic acid residue) the toxic effect of ricin A‐chain (in the absence of B‐chain) on intact cells became very close to that of the native toxin. As a result of stearic acid acylation, the activity of Staphylococcal enterotoxin A increased by nearly 1.5‐2 orders. The observed phenomena can be explained by receptor‐independent intracellular translocation of the hydrophobized toxins.
The role of the membrane skeleton in concanavalin A‐mediated agglutination of human erythrocytes
Authors: Pestonjamasp KN , Gokhale SM , Mehta NG
Published: October 2023

In the erythrocyte membrane, the mobility of band 3 protein, the receptor for concanavalin A (Con A), is drastically reduced by the membrane skeleton. Yet, the vesicles free of membrane skeletal proteins, isolated from the highly agglutinable proteinase‐treated cells, are found to be devoid of Con A agglutinability. The vesicles bind Con A in normal amounts, and remain agglutinable with the wheat germ and Ricinus agglutinins. Intracellular entrapment of monospecific antibodies to spectrin and 4.1 protein (two of the major skeletal components of the membrane) is also found to inhibit agglutination by 30–50%. Thus the membrane skeleton appears to play a positive role in the agglutination of the cells with Con A. The anti‐ankyrin antibodies are found to be without any effect. The anti‐band 3 (cytoplasmic domain) antibodies are also inhibitory to agglutination. Since Con A binding to cells alters the shape responses and deformability of the cells, and the cells resist fragmentation at 49 degrees C, the properties of the whole skeleton, especially spectrin, appear to be changed. The Con A‐bound membranes also do not release the complex of spectrin‐band 4.1‐actin when extracted with a hypotonic medium. It appears that Con A binding leads to interaction of the cytoplasmic domain of the receptor with a skeletal component, possibly spectrin. Subsequent to this, the receptor molecules and the skeletal proteins undergo aggregation in the membrane, which is detected by their crosslinking by an 8.6‐A span bifunctional reagent. The contractility believed to be associated with the membrane skeleton may be responsible for the aggregation.
Effect of cholesterol in various liposomal compositions on the in vivo toxicity, therapeutic efficacy, and tissue distribution of amphotericin B
Authors: Ahmad I. , Sarkar AK , Bachhawat BK
Published: October 2023

The effect of cholesterol in neutral, positively and negatively charged liposomes on the toxicity, therapeutic efficacy, and alteration in the tissue distribution pattern of amphotericin B (Amp‐B) in normal and infected mice was studied. It was observed that inclusion of cholesterol (CHOL) into egg phosphatidylcholine (EPC) liposomes increased the LD50 of Amp‐B from 5.3 to 8.5 mg/kg body weight. In the case of phosphatidylserine (PS) liposomes as well as stearylamine (SA) liposomes, cholesterol incorporation had no effect in altering the toxicity of the drug. The survival pattern of animals with all types of liposomal formulation of Amp‐B was similar. The tissue distribution studies indicated that in the case of normal mice, cholesterol inclusion in all types of liposomes increased the organ concentration of the drug in various tissues. In infected animals, the concentration of Amp‐B in all organs was increased when cholesterol was included in EPC and EPC/PS liposomes. The organ concentration of Amp‐B in lung and liver after 1 h of injection was the same in the case of EPC/SA and EPC/SA/CHOL liposomes. Considering the observations on toxicity, therapeutic efficacy, and tissue distribution, it was suggested that cholesterol had a beneficial therapeutic effect on neutral EPC liposomes.
Membrane lipid peroxidation by UV‐A: mechanism and implications
Authors: Bose B. , Agarwal S. , Chatterjee SN
Published: October 2023

UV‐A produced a dose‐dependent linear increase of lipid peroxidation in liposomal membrane, as detected by the assay of (i) conjugated dienes, (ii) lipid hydroperoxides, (iii) malondialdehydes (MDA), and (iv) the fluorescent adducts formed by the reaction of MDA with glycine and also a linear dose‐dependent increase of [14C]glucose efflux from the liposomes. UV‐A‐induced MDA production could not be inhibited by any significant degree by sodium formate, dimethyl sulfoxide, EDTA, or superoxide dismutase but was very significantly inhibited by butylated hydroxytoluene, alpha‐tocopherol, sodium azide, L‐histidine, dimethylfuran, and beta‐carotene. MDA formation increased with an increase in the D2O content in water, leading to a maximal amount of nearly 50% enhancement of lipid peroxidation in 100% D2O vis‐a‐vis water used as dispersion medium. The experimental findings indicate the involvement of singlet oxygen as the initiator of the UV‐A‐induced lipid peroxidation.
Carrier bound templates for single tube reverse transcriptase assays and for combined purification and activity analyses, with special reference to HIV
Authors: Gronowitz JS , Neumuller M. , Lennerstrand J. , Bhikhabhai R. , Unge T. , Weltman H. , Kallander CF
Published: October 2023

Polyriboadenosine (prA) was coupled to polycarbonate macrobeads or magnetic beads. The efficiency of the beads and of prA‐Sepharose, after priming with odT, as templates in activity assays of purified AMV‐ and HIV‐reverse transcriptase (RT), using [125I]iododeoxyuridine‐triphosphate as substrate, was studied. Although the use of immobilized templates, compared with soluble template, resulted in a decreased total molar turnover, it did not affect the sensitivity of the assay for detecting RT. The utility of the new assay was analyzed by mixing purified AMV‐ or HIV‐Rt with different dilutions of the untreated clinical specimen. This showed that RT activity was unaffected by 100 microliters of an extract of whole blood cells resuspended to their original blood volume and diluted 1/64, and also by 100 microliters of serum diluted 1/64. To improve the utility of the assay at the inhibitory concentrations of clinical specimens, the following procedure was adopted: the sample to be analyzed was incubated with the carrier bound template in order to allow the RT to bind, the carrier was washed to remove inhibitory factors, and the reaction components were then added to determine the amount of bound RT. This procedure greatly enhanced the recovery of RT activity from crude specimens and made the direct detection of HIV‐RT possible. The assay is easily automated and useful for RT determination in multiple samples and for determining RT‐inhibiting substances such as substrate analogs and antibodies.
Effects of growth temperature on toxicity of T‐2 toxin and roridin A to yeast
Authors: Gu TS , Koshinsky HA , Khachatourians GG
Published: October 2023

In yeasts, growth temperature is known to affect the membrane phospholipid content. The effect of temperature on the growth inhibition of Kluyveromyces marxianus and Saccharomyces cerevisiae by the trichothecene mycotoxins, T‐2 toxin and roridin A, was investigated. Examination of EC50 values for T‐2 toxin and roridin A showed that these toxins were least inhibitory to both yeasts at 30 and 25 degrees C, respectively. Increasing or decreasing growth temperature from these temperatures gradually increased the inhibitory effect of the trichothecene mycotoxins. Temperature may affect the toxicity of the trichothecenes to the yeasts by regulating the composition of yeast cell membranes.
Transfer and expression of a Streptomyces cholesterol oxidase gene in Streptococcus thermophilus
Authors: Somkuti GA , Solaiman DK , Johnson TL , Steinberg DH
Published: October 2023

The recombinant plasmid pNCO937 (8.1 kbp) containing a Streptomyces sp. cholesterol oxidase gene was introduced into Streptococcus thermophilus by electrotransformation. Transformation frequency was 7.2 times 10(5) colony forming units/micrograms of DNA. The presence of the cholesterol oxidase gene in S. thermophilus was confirmed with Southern blot analysis using a biotinylated probe. Thin‐layer chromatographic analysis showed the expression of the Streptomyces cholesterol oxidase gene resulting in the oxidation of cholesterol to 4‐cholesten‐3‐one. S. thermophilus may be a suitable host for the expression of other genes regulating prokaryotic cholesterol metabolism.
Stabilizing effect of organic solvents on oxyhemoglobin
Authors: Nedjar‐Arroume N. , Guillochon D. , Piot JM , Thomas D.
Published: October 2023

The role of hemoglobin solutions as oxygen carriers in biotechnology are numerous, such as in the oxygen supply to biocatalysts or in the preparation of blood substitutes. However, the major barrier to the successful use of hemoglobin in biological and medical engineering is the autoxidation of heme iron during preparation, storage, and utilization. Fifty‐six solvents, chosen among the group of Parker's classification, were studied with regard to the autoxidation kinetics of oxyhemoglobin under nondenaturant conditions. Among these solvents 27 present a concentration range in which the autoxidation rates were reduced compared to autoxidation in water. Three groups of solvent have been observed: one exhibiting only a destabilizing effect regardless of the solvent proportion, a second showing a strong stabilizing effect (k(H2O)/k(solvent) greater than 20) and a third showing a low stabilization (k(H2O)/k(solvent) less than 20). The most effective stabilizing solvents were glycerol, glycols, and alcohols. The effect of hydroorganic solvents could be explained by taking into account the globin solvation by water molecules. The solvents that enhance the structure of the water and form few hydrophobic interactions with globin prevent oxyhemoglobin autoxidation.
Purification and characterization of recombinant human insulin‐like growth factor II (IGF‐II) expressed as a secreted fusion protein in Escherichia coli
Authors: Wadensten H. , Ekebacke A. , Hammarberg B. , Holmgren E. , Kalderen C. , Tally M. , Moks T. , Uhlen M. , Josephson S. , Hartmanis M.
Published: October 2023

Human insulin‐like growth factor II (IGF‐II) was produced in an Escherichia coli ompT strain as a 22.5‐kDa fusion protein. IGF‐II was fused to the carboxy‐terminal of a synthetic 15‐kDa IgG‐binding protein, originating from staphylococcal protein A, via a unique methionine linker. During fermentation, the fusion protein was exported to the growth medium at levels exceeding 900 mg/liter and subsequently affinity purified on IgG Sepharose followed by ion exchange on S Sepharose. After chemical cleavage with CNBr, yielding an authentic IGF‐II molecule, the recombinant IGF‐II was purified to homogeneity by a two step procedure involving ion‐exchange and reverse‐phase HPLC. A substantial fraction of the secreted protein was found to be biologically active, eliminating the need for complex refolding procedures. The yield of highly purified and biologically active IGF‐II was 5–7 mg/liter of fermenter broth. The IGF‐II produced by this method displayed biochemical, immunological, receptor binding, and biological activity properties equal to those of native IGF‐II isolated from human serum.
The amino aldehydes produced by spermine and spermidine oxidation with maize polyamine oxidase have anti‐leishmanial effect
Authors: Cona A. , Federico R. , Gramiccia M. , Orsini S. , Gradoni L.
Published: October 2023

Purified maize polyamine oxidase bound to hydroxylapatite was utilized as an enzymatic reactor to produce oxidized spermidine and spermine. The oxidation products showed a consistent inhibitory activity on Leishmania infantum in mice. 1,3‐diaminopropane showed a much lower activity. Moreover chemically prepared 4‐aminobutyraldehyde had a similar ED50 to that of oxidized spermidine. It is concluded that among the compounds arising from polyamine oxidation those with the greatest anti‐leishmanial effect are 4‐aminobutyraldehyde and 1‐(3‐aminopropyl)‐4‐aminobutyraldehyde.
Efficient production of recombinant DNA proteins in Saccharomyces cerevisiae by controlled high‐cell‐density fermentation
Authors: Alberghina L. , Porro D. , Martegani E. , Ranzi BM
Published: October 2023

High levels of expression of heterologous proteins (from 5 to 15% of total cell proteins) in the budding yeast Saccharomyces cerevisiae have been obtained previously by the use of the inducible strong hybrid promoter UASGAL/CYC1, in batch as well in continuous cultures. However, in order to maximize the yield of heterologous proteins, a computer controlled fed‐batch fermentation is essential. For this reason we have developed a fed‐batch system based on a semiconductor gas detector that measures ethanol in the outflow gases. The optimal conditions are described for very high production (up to 1550 mg/liter), with both high productivity (up to 100–120 mg/liter/h) and high yield (up to 15 mg of protein/g of dry biomass), of heterologous protein driven by the UASGAL/CYC1 promoter in a completely computer controlled fed‐batch fermentation of budding yeast. However, high production was dependent upon the addition of a large amount of galactose. The process was improved by developing a new, more easily inducible, vector system obtained by subcloning the GAL4 gene.