bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding ATP binding to DosS catalytic domain with a short ATP-lid
Authors: Larson Grant , Windsor Peter , Smithwick Elizabeth , Shi Ke , Aihara Hideki , Damodaran Anoop Rama , Bhagi-Damodaran Ambika 
Published: May 2023

ABSTRACTDosS is a heme-sensor histidine kinase that responds to redox-active stimuli in mycobacterial environments by triggering dormancy transformation. Sequence comparison of the catalytic ATP-binding (CA) domain of DosS to other well-studied histidine kinases suggests that it possesses a rather short ATP-lid. This feature has been thought to inhibit DosS kinase activity by blocking ATP binding in the absence of interdomain interactions with the dimerization and histidine phospho-transfer (DHp) domain of full-length DosS. Here, we use a combination of computational modeling, structural biology, and biophysical studies to re-examine ATP-binding modalities in DosS’s CA domain. We show that the closed lid conformation observed in protein crystal structures of DosS CA is caused by the presence of a zinc cation in the ATP binding pocket that coordinates with a glutamate residue on the ATP-lid. Furthermore, circular dichroism (CD) studies and comparisons of DosS CA crystal structure with its AlphaFold model and homologous DesK reveal that a key N-box alpha-helix turn of the ATP pocket manifests as a random coil in the zinc-coordinated protein crystal structure. We note that this closed lid conformation and the random-coil transformation of an N-box alpha-helix turn are artifacts arising from the millimolar zinc concentration used in DosS CA crystallization conditions. In contrast, in the absence of zinc, we find that the short ATP-lid of DosS CA has significant conformational flexibility and can bind ATP (Kd= 53 ± 13 μM). We conclude that DosS CA is almost always bound to ATP under physiological conditions (1-5 mM ATP, sub-nanomolar free zinc) in the bacterial environment. Our findings elucidate the conformational adaptability of the short ATP-lid, its relevance to ATP binding in DosS CA and provide insights that extends to 2988 homologous bacterial proteins containing such ATP-lids.
Impact and role of hypothalamic corticotropin releasing hormone neurons in withdrawal from chronic alcohol consumption in female and male mice
Authors: Neira Sofia , Lee Sophia , Hassanein Leslie A. , Sides Tori , D’Ambrosio Shannon L. , Boyt Kristen M. , Bains Jaideep S. , Kash Thomas L. 
Published: May 2023

AbstractWorldwide, alcohol use and abuse are a leading risk of mortality, causing 5.3% of all deaths (W.H.O., 2022). The endocrine stress system, initiated by the peripheral release of corticotropin releasing hormone (CRH) from primarily glutamatergic neurons in the paraventricular nucleus of the hypothalamus (PVN), is profoundly linked with alcohol use, abuse, and relapse (Blaine & Sinha, 2017). These PVN CRH-releasing (PVNCRH) neurons are essential for peripheral and central stress responses (Rasiah et al., 2023), but little is known about how alcohol affects these neurons. Here, we show that two- bottle choice alcohol consumption blunts the endocrine mediated corticosterone response to stress during acute withdrawal in female mice. Conversely, using slice electrophysiology, we demonstrate that acute withdrawal engenders a hyperexcitable phenotype of PVNCRHneurons in females that is accompanied by increased glutamatergic transmission in both male and female mice. Only male mice show a concurrent increase in GABAergic synaptic transmission. We then tested whether chemogenetic inhibition of PVNCRHneurons would restore stress response in female mice with a history of alcohol drinking in the looming disc test, which mimics an approaching predator threat. Accordingly, inhibition of PVNCRHneurons reduced active escape in hM4Di alcohol history mice only. This study indicates that stress responsive PVNCRHneurons in females are particularly affected by a history of alcohol consumption. Interestingly, women have indicated an increase in heavy alcohol use to cope with stress (Rodriguez et al., 2020), perhaps pointing to a potential underlying mechanism in alcohol mediated changes to PVNCRHneurons that alter stress response.
Structural insights into the heterotrimeric alternatively spliced P2X7 receptors
Authors: De Salis Sophie K. F. , Chen Jake Zheng , Skarratt Kristen K. , Fuller Stephen J. , Balle Thomas 
Published: May 2023

SummaryAlphaFold2-Multimer was used to generate structures of the heterotrimeric P2X7 receptors composed of wild-type P2X7A subunits and alternatively spliced subunits (P2X7B, P2X7E, P2X7J, and P2X7L) that have been confirmed in humans. The study supports laboratory research by providing insight into the structure and flexibility of the heterotrimeric alternatively spliced receptors in a simulated environment and may thereby aid structure-guided drug design.AbstractP2X7 receptors (P2X7Rs) are membrane-bound ATP-gated ion channels that are composed of three subunits. Different subunit structures may be expressed due to alternative splicing of theP2RX7gene, altering the receptor’s function when combined with the wild-type P2X7A subunits. In this study, the application of the deep-learning method, AlphaFold2-Multimer (AF2M), for the generation of trimeric P2X7Rs was first validated by comparing an AF2M-generated rat wild-type P2X7A receptor with a structure determined by cryogenic electron microscopy (Protein Data Bank Identification: 6U9V). The results suggested AF2M could firstly, accurately predict the structures of P2X7Rs and secondly, accurately identify the highest quality model through the ranking system. Subsequently, AF2M was used to generate models of heterotrimeric alternatively spliced P2X7Rs consisting of one or two wild-type P2X7A subunits in combination with one or two P2X7B, P2X7E, P2X7J, and P2X7L splice variant subunits. The top-ranking models were deemed valid based on AF2M’s confidence measures, stability in molecular dynamics simulations, and consistent flexibility of the conserved regions between the models. Visual analysis of the heterotrimeric receptors identified missing residues in the ATP binding sites of the P2X7E, P2X7J, and P2X7L splice variants, likely translating into dysfunctional binding sites. Overall, the models produced in this study (available as supplementary material) unlock the possibility of structure-based studies into the heterotrimeric P2X7Rs.
Crystal structure of the monocupin ring-cleaving dioxygenase 5-nitrosalicylate 1,2-dioxygenase fromBradyrhizobiumsp.
Authors: Eppinger Erik , Stolz Andreas , Ferraroni Marta 
Published: May 2023

5-Nitrosalicylate 1,2-dioxygenase (5NSDO) is an iron(II)-dependent dioxygenase involved in the aerobic degradation of 5-nitroanthranilic acid by the bacteriumBradyrhizobiumsp. It catalyzes the opening of the 5-nitrosalicylate aromatic ring, a key step in the degradation pathway. Besides 5-nitrosalicylate, the enzyme is also active towards 5-chlorosalicylate. The X-ray crystallographic structure of the enzyme was solved at 2.1 Å resolution by molecular replacement using a model from the AI programAlphaFold. The enzyme crystallized in the monoclinic space groupP21, with unit-cell parametersa = 50.42,b= 143.17,c= 60.07 Å, β = 107.3°. 5NSDO belongs to the third class of ring-cleaving dioxygenases. Members of this family convertpara-diols or hydroxylated aromatic carboxylic acids and belong to the cupin superfamily, which is one of the most functionally diverse protein classes and is named on the basis of a conserved β-barrel fold. 5NSDO is a tetramer composed of four identical subunits, each folded as a monocupin domain. The iron(II) ion in the enzyme active site is coordinated by His96, His98 and His136 and three water molecules with a distorted octahedral geometry. The residues in the active site are poorly conserved compared with other dioxygenases of the third class, such as gentisate 1,2-dioxygenase and salicylate 1,2-dioxygenase. Comparison with these other representatives of the same class and docking of the substrate into the active site of 5NSDO allowed the identification of residues which are crucial for the catalytic mechanism and enzyme selectivity.
Role-play of employees' protean career and career success in affective organizational commitment
Authors: Khan Muhammad Latif , Salleh Rohani , Shamim Amjad , Hemdi Mohamad Abdullah 
Published: May 2023

PurposeThis paper aims to investigate the role-play of Protean Career Attitude (PCA) and Career Success (CS) in Affective Organizational Commitment (AOC).Design/methodology/approachA cross-sectional study on 376 employees from 55 hotels in Malaysia were conducted. The co-variance-based structural equation modeling was employed to analyze the data to test the direct and indirect relationships of PCA and CS with AOC.FindingsThe findings reveal that self-directed career attitude (SDCA) has a positive direct influence on AOC as well as indirect influence through the mediation of OCS and SCS. However, the value-driven career attitude (VDCA) neither influences AOC nor the OCS.Originality/valueThis is a first paper to body of knowledge in Asian context which identify mediating role of career success (SCA and OCS) to PCA and AOC. The findings of this research are the workplace learning in hospitality management. The authors argue that hotels should not assume spontaneously PCA with diminishing AOC, but rather hotels' attention is required to identify the most important preferences of these butterfly career attitudes such as OCS and SCS. Most importantly the research negates many negative labels of PCA and adds new perception to the contemporary career literature. Higher education institutions, government, and primary, secondary, and post-secondary education departments can play a significant role in developing PCA dispositions like SDCA and VDCA toward career success. Therefore, further study should examine PCA and their relevance to career outcome like job searching and employability of students in Malaysia. The paper is the first, to one's knowledge, to assess organizational commitment with specific measures of PCA. While the results are simple, they refute many stereotypes of the new career and, in that sense, add an important perspective to the career literature.
Managing mental health problems in the workplace: are small businesses different?
Authors: Irvine Annie , Suter Jane 
Published: May 2023

PurposeThis study addresses a gap in evidence on small employer experiences of managing mental health problems in the workplace. The authors gathered first-hand experiences of small business managers to empirically investigate how the small business context affects the management and support of mental health problems in the workplace, and the practice implications that arise.Design/methodology/approachQualitative interviews, combining semi-structured and narrative approaches, with 21 small business managers with experience of managing employees with mental health difficulties. The 21 managers recounted a total of 45 employee cases, which were analysed thematically, using a case-based matrix. Study participants were drawn from small businesses within England and Scotland (UK). Interviews were conducted between November 2019 and February 2020.FindingsSupport aligned with current understanding of effective practice, yet was often informal, instinctive and flexible. Accommodating employees with mental health problems impacted the workload of managers and co-workers, and business operation and growth. Challenges and tensions reflected the difficult balancing act faced by managers in organisations of all sizes. However, the intensity and immediacy of cross-pressures was enhanced for small businesses, due to their smaller workforce and lack of dedicated Human Resource Management and occupational health expertise.Practical implicationsGuidance should address the navigation of day-to-day management and support for employees with mental health difficulties, including approaches to balancing the needs of the wider workforce and business operation. Access to HR and occupational health expertise is valuable. Financial subsidies may be of lesser concern to small businesses.Originality/valueThis study offers originality in focusing exclusively on small business managers with first-hand experience of supporting employees with mental health problems. Findings challenge the perception that small firms have unique experiences, whilst highlighting contextual features that exacerbate intensity and immediacy of impacts.
Exploring the impact of an industrial placement year on students' competency development: a three-cohort, longitudinal study
Authors: Hughes Helen Philippa Narelle , Mouratidou Maria , Donald William E. 
Published: May 2023

PurposeDrawing on human capital theory and sustainable career theory, this paper aims to explore the impact of undertaking an industrial placement on the “Great Eight” competencies as perceived by university students and line managers.Design/methodology/approach618 students and their line managers across three cohorts (pre-COVID-19) took part in a longitudinal quantitative study. Students completed a three-wave questionnaire at the placement's start, middle, and end. Line managers completed the questionnaire during waves two and three to offer 360-degree feedback. Descriptive statistics and repeated measures ANOVA were applied to the dataset.FindingsThe impacts of undertaking a placement were highly variable for different competencies at the sub-scale level, although at the eight-scale level, the nuance was less pronounced. However, students self-perceived that all eight competencies increased between the start and end of the placement. Surprisingly, line managers perceived students' competencies to be higher than perceived by the students.Originality/valueThe value of undertaking a placement is often poorly measured (e.g. satisfaction) rather than competency-based outcomes, which can lead to conclusions that are overly simplistic and difficult to use in practice. Theoretically, this study advances understanding of human capital theory and sustainable career theory by understanding the role placements can play in developing human capital and preparing university students for sustainable careers. Practically, the findings of this study can help to close the university–industry skills gap by informing curriculum and placement scheme design and supporting students to acquire personal resources and signal these to prospective employers as an antecedent to career sustainability.
Fuzzy logic approach to assess the effectiveness of online course delivery in management education: a case of B-school from India
Authors: Patri Rojalin , Manayath Dhanya , Kaladharan Sanju 
Published: May 2023

PurposeThe future of management studies is invariably steering towards online and hybrid modes of course delivery. Therefore, assessing the effectiveness of online course delivery is exceptionally crucial. This study attempts to evaluate the effectiveness of online course delivery in management education involving the instructor, participant and technological component. This study contributes to the body of knowledge in three ways. First, the study proposes an approach to assess the effectiveness of online courses in management education. The study demonstrates this by taking a case study of a business school (B-school) in southern India. Second, the study identifies the shortcomings and areas that need improvement to enhance the overall effectiveness further. Third, the study outlines suggestive measures to improve the effectiveness of online course delivery by addressing technical, infrastructural, instructor and student behavioral components.Design/methodology/approachTo accomplish the objectives, a case study approach has been adopted and fuzzy logic has been used as a methodology to assess the effectiveness of online course delivery in management education.FindingsThe findings suggest that instructors' use of cases and animation during online sessions, use of whiteboards, digital pens and other tools, attempts to draw participant's interest and the users' sense of belongingness in the online cohort, self-discipline and motivation from students' side, easy to use Learning Management System (LMS), audio-visual platforms, active electronic communication and training on the technical aspect of the online platform need to be improved to enhance the effectiveness of online course delivery further. The current effectiveness of online course delivery in the case of B-school was found to be “Fair,” which is average in relation to the effectiveness labels.Research limitations/implicationsThis study doesn't investigate the factors that moderate the effectiveness of online course delivery and how the factors influence each other. Future research endeavors can be extended in this direction to enrich the body of knowledge with new insights. Apart from this, the results outlined in this study are about the status quo of the case B-school and can't be generalized. However, the methodology and approach can be adopted by other B-schools or higher educational institutes to measure the schools' and institutes' current level of effectiveness in online teaching.Originality/valueSo far, only a few studies have paid attention to the empirical assessment of the effectiveness of online course delivery consisting of engagement from the technical, instructor and participants' dimensions. This study proposes a novel approach to measure the level of effectiveness and identifies the shortfalls that impede good effectiveness in online course delivery.
The search for an appropriate condensation model to simulate wet steam transonic flows
Authors: Lakzian Esmail , Ramezani Mostafa , Shabani Sima , Salmani Fahime , Majkut Miroslaw , Kim Heuy Dong 
Published: May 2023

Purpose
The purpose of this study is to model steam condensing flows through steam turbine blades and find the most suitable condensation model to predict the condensation phenomenon.

Design/methodology/approach
To find the most suitable condensation model, five nucleation equations and four droplet growth equations are combined, and 20 cases are considered for modelling the wet steam flow through steam turbine blades. Finally, by the comparison between the numerical results and experiments, the most suitable case is proposed. To find out whether the proposed case is also valid for other boundary conditions and geometries, it is used to simulate wet steam flows in de Laval nozzles.

Findings
The results indicate that among all the cases, combining the Hale nucleation equation with the Gyarmathy droplet growth equation results in the smallest error in the simulation of wet steam flows through steam turbine blades. Compared with experimental data, the proposed model’s relative error for the static pressure distribution on the blade suction and pressure sides is 2.7% and 2.3%, respectively, and for the liquid droplet radius distribution it totals to 1%. This case is also reliable for simulating condensing steam flows in de Laval nozzles.

Originality/value
The selection of an appropriate condensation model plays a vital role in the simulation of wet steam flows. Considering that the results of numerical studies on condensation models in recent years have not been completely consistent with the experiments and that there are still uncertainties in this field, further studies aiming to improve condensation models are of particular importance. As condensation models play an important role in simulating the condensation phenomenon, this research can help other researchers to better understand the purpose and importance of choosing a suitable condensation model in improving the results. This study is a significant step to improve the existing condensation models and it can help other researchers to gain a revealing insight into choosing an appropriate condensation model for their simulations.
Uniform magnetic field impact on absolute versus convective onset of Darcy–Benard convection with horizontal throughflow
Authors: Turkyilmazoglu Mustafa 
Published: May 2023

Purpose
The onset of Darcy–Benard convection in a fluid-saturated porous layer within channeled walls can be through either the convectively amplified perturbations or absolutely unstable modes. The convective type route to formation of cellular forms has received much more interest in the literature than the absolute mode. This paper aims to explore the absolute instability mechanism on triggering the Benard convection in the presence of a uniform magnetic field acting perpendicular to the channel walls.

Design/methodology/approach
Pursuing a completely theoretical linear stability approach, the locus of wavenumbers and critical Rayleigh numbers with respect to varying Peclet numbers leading to zero complex group velocity, and hence the absolute instability onset, is formulated in closed form. The formulae also incorporate the influence of fluid movement through the porous layer.

Findings
Wanenumbers are found to be increasing in magnitude under the effect of the magnetic field. Although the magnetic field expectedly behaves in favor of stabilizing the convection through both convective and absolute instabilities by pushing the threshold value of Rayleigh number to higher values, a peculiarity exists in such a manner that the stabilizing effect of magnetic field can no longer compete against the absolute instability mechanism within the magnetized field after some critical location possessing negative part of the wavenumber.

Originality/value
The significant outcome is attributed to the exchange of instabilities as far as the absolute instability mechanism is concerned. Magnetic field is always stabilizing and no such trend is observed regarding the convective type instability.