bluuebunny/crossref_metadata_2025_split huggingface dataset:
Replication-competent HIV-1 in human alveolar macrophages and monocytes despite nucleotide pools with elevated dUTP
Authors: Cui Junru , Meshesha Mesfin , Churgulia Natela , Merlo Christian , Fuchs Edward , Breakey Jennifer , Jones Joyce , Stivers James T. 
Published: May 2022

AbstractAlthough CD4+ memory T cells are considered the primary latent reservoir for HIV-1, replication competent HIV has been detected in tissue macrophages in both animal and human studies. During in vitro HIV infection, the depleted nucleotide pool and high dUTP levels in monocyte derived macrophages (MDM) leads to proviruses with high levels of dUMP, which has been implicated in viral restriction or reduced transcription depending on the uracil base excision repair (UBER) competence of the macrophage. Incorporated dUMP has also been detected in viral DNA from circulating monocytes (MC) and alveolar macrophages (AM) of HIV infected patients on antiretroviral therapy (ART), establishing the biological relevance of this phenotype but not the replicative capacity of dUMP-containing proviruses. As compared to in vitro differentiated MDM, AM from normal donors had 6-fold lower levels of dTTP and a 6-fold increased dUTP/dTTP, indicating a highly restrictive dNTP pool for reverse transcription. Expression of uracil DNA glycosylase (UNG) was 8-fold lower in AM compared to the already low levels in MDM. Accordingly, ∼80% of HIV proviruses contained dUMP, which persisted for at least 14-days due to low UNG excision activity. Unlike MDM, AM expression levels of UNG and SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) increased over 14 days post-HIV infection, while dUTP nucleotidohydrolase expression decreased. These AM-specific effects suggest a restriction response centered on excising uracil from viral DNA copies and increasing relative dUTP levels. Despite the restrictive nucleotide pools, we detected rare replication competent HIV in AM, peripheral MC, and CD4+ T cells from ART-treated donors. These findings indicate that the potential integration block of incorporated dUMP is not realized during in vivo infection of AM and MC due to the near absence of UBER activity. In addition, the increased expression of UNG and SAMHD1 in AM post-infection is too slow to prevent integration. Accordingly, dUMP persists in integrated viruses, which based on in vitro studies, can lead to transcriptional silencing. This possible silencing outcome of persistent dUMP could promote viral latency until the repressive effects of viral dUMP are reversed.
EEG Movement Tagging Objectively Measures Biological Motion Perception
Authors: Cracco Emiel , Oomen Danna , Papeo Liuba , Wiersema Jan R. 
Published: May 2022

AbstractDetecting biological motion is essential for adaptive social behavior. Previous research has revealed the brain processes underlying this ability. However, brain activity during biological motion perception captures a multitude of components. As a result, it is often unclear which components reflect movement processing and which components reflect secondary processes building on movement processing. To address this issue, we developed a new approach that objectively defines the brain response associated with biological motion perception.Specifically, we showed 30 male and female adults a point-light walker moving at a pace of 2.4 Hz and used EEG frequency tagging to measure the brain response coupled to that pace (‘movement tagging’). The results revealed a reliable response at the walking frequency that was reduced by two manipulations known to disrupt biological motion perception: phase scrambling and inversion. Interestingly, we also identified a brain response at half the walking frequency (i.e., 1.2 Hz), corresponding to the rate at which the individual dots completed a cycle. In contrast to the 2.4 Hz response, the response at 1.2 Hz was increased for scrambled walkers. These results show how frequency tagging can be used to objectively measure the visual processing of biological movements and can dissociate between global (2.4 Hz) and local (1.2 Hz) processes involved in biological motion perception, at different frequencies of the brain signal.
Subfunctionalized expression drives evolutionary retention of ribosomal protein paralogs in vertebrates
Authors: Xu Adele , Molinuevo Rut , Fazzari Elisa , Tom Harrison , Zhang Zijian , Menendez Julien , Casey Kerriann M. , Ruggero Davide , Hinck Lindsay , Pritchard Jonathan K. , Barna Maria 
Published: May 2022

AbstractThe formation of paralogs through gene duplication is a core evolutionary process. For paralogs that encode components of protein complexes such as the ribosome, a central question is whether they encode functionally distinct proteins, or whether they exist to maintain appropriate total expression of equivalent proteins. Here, we systematically tested evolutionary models of paralog function using the mammalian ribosomal protein paralogs eS27 (Rps27) and eS27L (Rps27l) as a case study. We first showed that eS27 and eS27L have inversely correlated mRNA abundance across cell types, with the highest eS27 in lymphocytes and the highest eS27L in mammary alveolar cells and hepatocytes. By endogenously tagging the eS27 and eS27L proteins, we demonstrated that eS27- and eS27L- ribosomes associate preferentially with different transcripts. Furthermore, we generated murine eS27 and eS27L loss-of-function alleles that are homozygous lethal at different developmental stages. However, strikingly, we found that expressing eS27 protein from the endogenous eS27L locus, or vice versa, completely rescues loss-of-function lethality and yields mice with no detectable deficits. Together, these findings suggest that eS27 and eS27L are evolutionarily retained because their subfunctionalized expression patterns render both genes necessary to achieve the requisite total expression of two equivalent proteins across cell types. Our work represents the most in-depth characterization of a mammalian ribosomal protein paralog to date and highlights the importance of considering both protein function and expression when investigating paralogs.
Variations of a theme - crystal forms of the amino acid transporter MhsT
Authors: Neumann Caroline , Focht Dorota , Trampari Sofia , Lyons Joseph , Nissen Poul 
Published: May 2022

AbstractThe bacterial amino acid transporter MhsT of the SLC6A family was crystallized in complex with different substrates in order to understand the determinants of substrate specificity of the transporter. Surprisingly, crystals of the different MhsT-substrate complexes showed interrelated, but different crystal packing arrangements. Space group assignment and structure determination of these different crystal forms presented challenging combinations of pseudosymmetry, twinning and tNCS.SynopsisAn unusual case of protein-substrate complexes obtained in similar conditions, but containing different packing arrangements. The crystals exhibit a combination of various crystal imperfections (pseudosymmetry, twinning and tNCS) masking the true crystal symmetries and challenging data processing and structure determination.
Aminomethanesulfonic acid illuminates the boundary between full and partial agonists of the pentameric glycine receptor
Authors: Ivica Josip , Zhu Hongtao , Lape Remigijus , Gouaux Eric , Sivilotti Lucia G. 
Published: May 2022

ABSTRACTTo clarify the determinants of agonist efficacy in pentameric ligand-gated ion channels we examined a new compound, aminomethanesulfonic acid (AMS), a molecule intermediate in structure between glycine and taurine. Despite wide availability, to date there are no reports of AMS action on glycine receptors, perhaps because AMS is unstable at physiological pH. Here we show that at pH 5, AMS is an efficacious agonist, eliciting in zebrafish α1 glycine receptors a maximum single channel open probability of 0.85, much greater than that of β-alanine (0.54) or taurine (0.12), and second only to that of glycine itself (0.96). Thermodynamic cycle analysis of the efficacy of these closely related agonists shows supra-additive interaction between changes in the length of the agonist molecule and the size of the anionic moiety. Single particle cryo-EM structures of AMS-bound glycine receptors show that the AMS-bound agonist pocket is as compact as with glycine, and three-dimensional classification demonstrates that the channel populates the open and the desensitized states, like glycine, but not the closed intermediate state associated with the weaker partial agonists, β-alanine and taurine. Because AMS is on the cusp between full and partial agonists, it provides a new tool to help us understand agonist action in the pentameric superfamily of ligand-gated ion channels.
Regulation of astrocyte lipid metabolism and ApoE secretion by the microglial oxysterol, 25-hydroxycholesterol
Authors: Cashikar Anil G , Rios Danira Toral , Timm David , Romero Johnathan , Long Justin M , Han Xianlin , Holtzman David M. , Paul Steven M 
Published: May 2022

ABSTRACTNeuroinflammation is a major hallmark of Alzheimer’s disease and several other neurological and psychiatric disorders and is often associated with dysregulated cholesterol metabolism. Relative to homeostatic microglia, activated microglia express higher levels of Ch25h, an enzyme that hydroxylates cholesterol to produce 25-hydroxycholesterol (25HC). 25HC is an oxysterol with interesting immune roles stemming from its ability to regulate cholesterol biosynthesis. Since astrocytes synthesize cholesterol in the brain and transport it to other cells via apolipoprotein E (ApoE)-containing lipoproteins, we hypothesized that secreted 25HC from microglia may influence lipid metabolism as well as extracellular ApoE derived from astrocytes. Here we show that astrocytes take up externally added 25HC and respond with altered lipid metabolism. 25HC increased extracellular levels of ApoE lipoprotein particles without altering Apoe mRNA expression, due to elevated Abca1 expression via activation of LXRs and decreased ApoE reuptake due to suppressed Ldlr expression via inhibition of SREBP. Astrocytes metabolized 25HC to limit its effects on lipid metabolism via Cyp7b1, an enzyme responsible for 7α-hydroxylation of 25HC. Knockdown of Cyp7b1 expression with siRNA prolonged the effects of 25HC on astrocyte lipid metabolism. 25HC also suppressed Srebf2 expression to reduce cholesterol synthesis in astrocytes but did not affect fatty acid levels or the genes required for fatty acid synthesis. We further show that 25HC led to a doubling of the amount of cholesterol esters and their concomitant storage in lipid droplets. Our results suggest an important role for 25HC in regulating astrocyte lipid metabolism.
The Systematic Optimization of Square Wave Electroporation for Six Commonly Used Human Cell Lines
Authors: Vieira Christian , Nesmith Thomas , Acharya Saujanya , Gupta Gagan D. 
Published: May 2022

AbstractDuring cellular electroporation, the formation of transient pores allow for the diffusion of innately impermeable molecules. The diversity of cell and membrane structure results in unique properties with respect to sensitivity to electric fields. The growing use of human cell lines in biomedical research and technology has led to a demand for protocols that can effectively and economically perform electroporation. We electroporated six human cell lines using a fluorescent reporter to investigate the effects of pulse electric field strength, pulse duration, and DNA concentration during electroporation. It was found that the cell lines all responded to electric field strengths within 400-950V/cm with viability decreasing with increasing voltage. It was also observed that the concentration of DNA used directly impacts transfection efficiency and cell viability as well. To better characterize square wave electroporation, we adopted a model where the pulse is described by its energy density (J/L) with respect to the sample buffer volume. It was determined that the key electrical characteristics of electroporation can be generalized with this value to provide a simplified measure of pulse intensity. The resulting analysis was consistent with other models, indicating cell type specific optimal electrical and DNA concentrations.
Barriers constraining the growth of and potential solutions for emerging entrepreneurial SMEs
Authors: Khan Muhammad Asif 
Published: May 2022

Purpose
Pakistan has marvellous growth and development capacity, and entrepreneurial small- and medium-sized enterprises (SMEs) play a key role in its development. As it is believed that entrepreneurial SMEs make an important contribution to the economy by providing employment and soaring production capacity, the purpose of this study is to investigate the hurdles that affect their performance.

Design/methodology/approach
A questionnaire-based survey was used to collect data from 225 entrepreneurial SMEs owners and managers in the southern region of Pakistan. Statistical analysis in SPSS was conducted to determine the barriers that limit the growth and development of SMEs.

Findings
The findings show that factors affecting entrepreneurial SMEs’ performance in Pakistan are lack of finance and infrastructure as well as economic barriers, corruption and management issues. These obstacles are positively and significantly associated with entrepreneurial SMEs’ failure.

Originality/value
This study’s significance lies in its identification of the barriers that affect the performance of entrepreneurial SMEs in Pakistan. The author also suggests how policymakers can devise better policies for SME growth.
Relationships between patient flow problems, health care services, and patient satisfaction: an empirical investigation of the emergency department
Authors: Al Owad Ali , Islam Mazharul , Samaranayake Premaratne , Karim Azharul 
Published: May 2022

PurposeThe purpose of this study is to establish empirical relationships between patient flow problems, healthcare service quality and patient satisfaction with emergency department (ED) service factors from the patient perspective.Design/methodology/approachIn the overall study, of which the current investigation is a part, a mixed-method research approach was to achieve the research objectives. The results reported in this paper are based on a comprehensive questionnaire survey where a well-designed and reliable questionnaire was used to survey ED patients. This study conducted partial least squares structural equation modelling (PLS-SEM) by using Smart PLS software.FindingsResults show that the respondents mostly agreed with the proposed concept of quality in ED and patients were less satisfied with ED services in general and with the internal and external environments in ED in particular. It was found that relationships between nine identified scales of patient flow problems, healthcare service quality, and patient satisfaction are significant. The findings reveal that the relationship between patient flow problems and patient satisfaction is positively mediated through healthcare service quality, which shows the predictive capability of the model, indicating high predictive relevance.Research limitations/implicationsThis research involves a relatively small sample from a single case study. The positive relationship between patient flow problems and patient satisfaction indicate practical significance of the model for guiding to improve overall patient satisfaction.Originality/valueThis research, through the involvement of both hospital staff and the patient, brings out a holistic approach in terms of operational excellence in a critical unit such as the ED. The empirically established relationships form the benchmarking and guide for developing guidelines for designing policies for service improvements of ED practices.
To disclose or not disclose a workplace disability to coworkers: attributions and invisible health conditions in the workplace
Authors: Patton Eric 
Published: May 2022

PurposeThe decision to disclose an illness is a difficult choice for many individuals. Despite national laws such Americans with Disabilities Act that protect workers with disabilities from discrimination in the workplace, the stigmas around certain illnesses, fears of being judged by others using different standards, and concerns about a lack of support regardless of legal requirements are all reasons why someone may hesitate to disclose a health condition in the workplace.Design/methodology/approachUsing experimentally manipulated vignettes and a combination of theories on attribution and incivility, this study explores the dangers of not disclosing a disability/condition that can lead to behaviors that will engender judgments by coworkers.FindingsThe results of the study make clear that there are social benefits to disclosing a health condition rather than concealing. The findings clearly demonstrate that attributing an individual's negative behavior to their disposition will lead to more judgments of responsibility, and less sympathy and more anger compared to behaviors that can be explained by any health reason. Furthermore, more punishment, feelings of revenge and social distancing await individuals whose negative behavior cannot be explained by health issues.Originality/valueThis study combines issues of health, attributions, incivility in an experimental studies that illuminates issues surround disclosing a workplace disability that go beyond the typical focus of legal questions.
Polymatic plastics & packaging – market deepening versus geography expansion
Authors: Mathur Dhiraj , Narayanamurthy Gopalakrishnan , Sengupta Tuhin 
Published: May 2022

Learning outcomes
Learning outcomes are as follows: to understand the need for a small business to expand geographically; to evaluate the business dynamics and challenges faced by an entrepreneur during the business life cycle; and to analyze the geography and create a growth strategy for small business setup in a phase where competition is moving from a moderate to an intense stage.

Case overview/synopsis
Polymatic Plastics & Packaging (PPP), a proprietorship firm of Mr Shantanu Kalia at Ludhiana, Punjab, India, was formed in 2016 and is involved in the manufacturing of bubble packing and stretch films. Growing business and competition have created both unique challenges as well as propositions for PPP. While growth in business is encouraging Shantanu to secure more contracts for his manufacturing unit, increased competition within Ludhiana is also creating a dilemma to either compete on home turf with USPs ranging from product quality, pricing and superior turn-around-time or explore additional geographies and expand horizontally.

Complexity academic level
The case is suitable for courses on entrepreneurship and geography strategy in graduate business programs. The case is also suitable for executive program for budding entrepreneurs seeking to explore specific service/product as a potential business proposition and building their business around it.

Supplementary materials
Teaching notes are available for educators only.

Subject code
CSS 3: Entrepreneurship.
The mental health support needs of university students with long-term physical health conditions
Authors: Wilson Ceri , Spencer Grace 
Published: May 2022

PurposeSupporting the mental health of university students is a key priority for higher education. Students living with long-term health conditions are at increased risk of poor mental health; yet little work has focused on their particular mental health needs or indeed, the implications for health education in the university setting. This study sought to identify the mental health support needs of students with long-term conditions, including best ways for universities to support these students.Design/methodology/approachA UK national online survey of 200 university students living with long-term physical health conditions (e.g. asthma, endometriosis, epilepsy) was conducted in 2019.Findings95% of respondents reported that their long-term condition/s had at least a moderate impact on their mental wellbeing, with 81% reporting that they felt depressed and anxious at least once a month because of their health. The most common suggestion for how universities can better support their mental wellbeing was to raise awareness about long-term conditions on campuses, with many reporting a lack of understanding about long-term conditions from academic and support services staff members – with negative impacts on their mental health. Because of this, some respondents reported a reluctance to come forward and seek help from university services, with 25% not formally disclosing their conditions.Originality/valueThese reported concerns underscore the need to develop health education amongst university staff about long-term conditions and to ensure these students are supported with their health at university.
A systematic review of green building practices implementation in Africa
Authors: Ebekozien Andrew , Aigbavboa Clinton , Thwala Wellington Didibhuku , Amadi Godpower Chinyeru , Aigbedion Marvelous , Ogbaini Iliye Faith 
Published: May 2022

Purpose
The purpose of this study is to conduct a systematic review on encumbrances facing the implementation of GBP in selected African countries. Green building practices (GBP) implementation is germane and promotes the development of a green environment and buildings. Many studies have been conducted on the encumbrances faced with GBP implementation, especially in developing countries. But evidence of a comprehensive study that investigates and analyses these hindrances from different developing countries is missing. Therefore, a systematic review is conducted systematically reviewing the current literature on encumbrances facing the implementation of GBP in selected African countries. Also, the study proffers possible drivers for stakeholders to promote GBP in African countries.

Design/methodology/approach
A total of 38 published papers were identified from the Web of Science, Scopus database and supported with materials from Google Scholar related to Africa’s GBP. The continent was divided into five regions, and each region covered three countries.

Findings
Two themes emerged from the analysed review – encumbrances facing GBP implementation and possible drivers for stakeholders to promote GBP in African countries. A total of 18 encumbrances and 18 drivers were identified from the analysed literature and grouped into 6 sub-themes.

Research limitations/implications
Current empirical articles were reviewed to suggest the drivers for stakeholders to promote GBP that emerged from this paper. Thus, to enrich the results from this paper, primary source data of regional studies of GBP in Africa’s context should be carried out via the mixed-methods design.

Practical implications
A total of 18 drivers were identified for stakeholders to promote GBP in Africa and form part of the paper’s implications. Also, the paper findings would serve as a treasured suggestion for the stakeholders (policymakers, construction practitioners, clients and academics) who are fascinated by the promotion of GBP across African nations.

Originality/value
This is possibly the foremost analysed systematic review study on GBP implementation in Africa. Therefore, it fills the theoretical gap and proffers possible drivers for stakeholders to promote GBP in the African context.