bluuebunny/crossref_metadata_2025 huggingface dataset:
A Reference Data Set for Circular Dichroism Spectroscopy Comprised of Validated Intrinsically Disordered Protein Models
Authors: Nagy Gabor , Jones Nykola C. , Hoffmann Soren V , Grubmueller Helmut
Published: October 2023

Circular Dichroism (CD) spectroscopy is an analytical technique that measures the wavelength-dependent differential absorbance of circularly polarized light, and is applicable to most biologically important macromolecules, such as proteins, nucleic acids, and carbohydrates. It serves to characterize the secondary structure composition of proteins, including intrinsically disordered proteins, by analyzing their recorded spectra. Several computational tools have been developed to interpret protein CD spectra. These methods have been calibrated and tested mostly on globular proteins with well-defined structures, mainly due to the lack of reliable reference structures for disordered proteins. It is therefore still largely unclear how accurately these computational methods can determine the secondary structure composition of disordered proteins. Here, we provide such a required reference data set consisting of model structural ensembles and matching CD spectra for eight intrinsically disordered proteins. Using this set of data, we have assessed the accuracy of several published CD prediction and secondary structure estimation tools, including our own CD analysis package SESCA. Our results show that for most of the tested methods, their accuracy for disordered proteins is generally lower than for globular proteins. In contrast, SESCA, which was developed using globular reference proteins, but was designed to be applicable to disordered proteins as well, performs similarly well for both classes of proteins. The new reference data set for disordered proteins should allow for further improvement of all published methods.
Microtubule inner proteins ofPlasmodiumare essential for transmission of malaria parasites
Authors: Hentzschel Franziska , Binder Annika M. , Dorner Lilian P , Herzel Lea , Nuglish Fenja , Sema Meslo , Aguirre-Botero Manuela C. , Cyrklaff Marek , Funaya Charlotta , Frischknecht Friedrich
Published: October 2023

Microtubule inner proteins, MIPs, are microtubule associated proteins that bind to tubulin from the luminal side. MIPs can be found in axonemes to stabilize flagellar beat or within cytoplasmic microtubules.Plasmodiumspp. are the causative agents of malaria that feature different forms across a complex life cycle with both unique and divergent microtubule-based arrays. Here we investigate the role of four MIPs in a rodent malaria parasite for their role in transmission to and from the mosquito. We show by single and double gene deletions that SPM1 and TrxL1, MIPs associated with the subpellicular microtubules are dispensable for transmission from the vertebrate host to the mosquito and back. In contrast, FAP20 and FAP52, MIPs associated with the axonemes of gametes, are essential for transmission to mosquitoes but only if both genes are deleted. In the absence of both, FAP20 and FAP52 the B-tubule of the axoneme partly detaches from the A-tubule resulting in the deficiency of axonemal beating and hence gamete formation and egress. Our data suggest that a high level of redundancy ensures microtubule stability in the transmissive stages ofPlasmodium, which is important for parasite transmission.
Memory consolidation in honey bees is enhanced by down-regulation ofDown Syndrome Cell Adhesion Moleculeand changes its alternative splicing
Authors: Ustaoglu Pinar , McQuarrie David W. J. , Rochet Anthony , Dix Thomas , Haussmann Irmgard U. , Arnold Roland , Devaud Jean-Marc , Soller Matthias
Published: October 2023

Down syndrome cell adhesion molecule (Dscam) gene encodes a cell adhesion molecule required for neuronal wiring. A remarkable feature of invertebrateDscamis massive alternative splicing generating thousands of different isoforms from three variable clusters of alternative exons.Dscamexpression and diversity arising from alternative splicing have been studied during development, but whether they exert functions in differentiated brains has not been determined. Here, using honey bees, we find that Dscam expression is critically linked to memory retention as reducing expression by RNAi enhances memory after reward learning in adult worker bees. Moreover, alternative splicing ofDscamis altered in all three variable clusters after learning. Since identical Dscam isoforms engage in homophilic interactions, these results suggest a mechanism to alter inclusion of variable exons during memory consolidation to modify neuronal connections for memory retention.
Histamine originating from the BNST modulates corticostriatal synaptic transmission during early postnatal development
Authors: Márquez-Gómez Ricardo , Parke Brenna , Cras Yasmin , Gullino Sophie L. , Hashemi Parry , Ellender Tommas
Published: October 2023

The neuromodulator histamine regulates key processes in many regions of both the adult and developing brain including the striatum. However, striatal innervation by histaminergic afferents is very sparse making the physiological sources of histamine controversial. Here potential sources of striatal histamine were investigated during early postnatal development and specifically in the second postnatal week, in acute mouse brain slices. Firstly, a combination of whole-cell patch-clamp recordings and optogenetic stimulation demonstrates that during this period exogenously applied histamine modulates the intrinsic properties of developing D1and D2striatal spiny projection neurons (SPNs) as well as synaptic transmission at afferents coming from the mPFC and visual cortex. Secondly, immunohistochemistry for histamine reveals a brain region proximal and caudal to striatum densely innervated by histaminergic axons and corresponding to the oval nucleus of the bed nucleus of stria terminalis (ovBNST). Thirdly, direct electrical stimulation of the ovBNST leads to significant and detectable levels of histamine in the striatum, as assessed by both fast scan cyclic voltammetry and fluorescent histamine sensors. Lastly, electrical stimulation of the ovBNST nucleus, at frequencies mimicking active histaminergic neurons, can release sufficient levels of histamine to modulate excitatory synaptic transmission from mPFC onto striatal SPNs by acting at histamine H3receptors. Together, these results provide evidence for the existence of the ovBNST as an extrastriatal source of histamine during early brain development and postulates a new view of the modus operandi of histamine in that it can cross anatomical boundaries and act as a paracrine neuromodulator.

Significance statement

Histamine is synthesized by neurons in the hypothalamic tuberomammillary nucleus (TMN) and released from their axons in many brain regions controlling key physiological processes. When dysregulated this can result in neurological and neurodevelopmental disorders such as Tourette’s syndrome and OCD. To understand the physiological roles for histamine and to facilitate the generation of new therapeutic interventions it is key to define the sources of histamine and its mode of action. Here we provide evidence, using the developing striatum as an exemplar, that sources of histamine can lie beyond anatomical boundaries with histamine acting as a paracrine neuromodulator. This also has potential implications for our mechanistic understanding of deep brain stimulation of the BNST in treating severe Tourette’s syndrome and OCD.
Filamentation and inhibition of prokaryotic CTP synthase
Authors: Guo Chen-Jun , Wang Zi-Xuan , Liu Ji-Long
Published: October 2023

CTP synthase (CTPS) plays a pivotal role in the de novo synthesis of CTP, a fundamental building block for RNA and DNA, which is essential for life. CTPS is capable of directly binding to all four nucleotide triphosphates: ATP, UTP, CTP, and GTP. Furthermore, CTPS can form cytoophidia in vivo and metabolic filaments in vitro, undergoing regulation at multiple levels. CTPS is considered a potential therapeutic target for combating invasions or infections by virus or prokaryotic pathogens. Utilizing cryo-electron microscopy, we have determined the structure ofEscherichia coliCTPS (ecCTPS) filament in complex with CTP, NADH, and the covalent inhibitor DON, achieving a resolution of 2.8Å. We construct a phylogenetic tree based on differences in filament-forming interfaces and design a variant to validate our hypothesis, providing an evolutionary perspective on the CTPS filament formation. Our computational analysis reveals a solvent-accessible ammonia tunnel upon DON binding. By comparative structural analysis, we discern a distinct mode of CTP binding of ecCTPS, differing from eukaryotic counterparts. Combining biochemical assays and structural analysis, we determine and validate the synergistic inhibitory effects of CTP with NADH or adenine on CTPS. Our results expand our comprehension of diverse regulatory aspects of CTPS and lay a foundation for the design of specific inhibitors targeting prokaryotic CTPS.
The heme precursor 5-aminolevulinic acid triggers the shutdown of the HemKR signalling system inLeptospira
Authors: Imelio Juan Andrés , Trajtenberg Felipe , Mondino Sonia , Zarantonelli Leticia , Vitrenko Iakov , Lemée Laure , Cokelaer Thomas , Picardeau Mathieu , Buschiazzo Alejandro
Published: October 2023

Heme and iron metabolic pathways are highly intertwined, both compounds being essential for key biological processes, yet becoming toxic if overabundant. Their concentrations are exquisitely regulated, including via dedicated two-component systems (TCSs) that sense signals and regulate adaptive responses. HemKR is a TCS involved in the control of heme metabolism inLeptospiraspirochetes. However, the signals and molecular means by which HemKR is switched on/off, are still unknown. Moreover, a comprehensive list of HemKR-regulated genes, potentially overlapped with iron-responsive targets, is also missing. Here we show that 5-aminolevulinic acid (ALA), a committed porphyrin biosynthesis precursor, triggers the shutdown of the HemKR pathway by stimulating the phosphatase activity of HemK towards phosphorylated HemR. HemR dephosphorylation leads to differential expression of multiple genes, including of heme metabolism and transport systems. Furthermore, HemR inactivation brings about an iron-deficit tolerant phenotype, synergistically with iron-responsive signalling systems. Such tolerance could be vital during infection in pathogenicLeptospiraspecies, which comprise a conserved HemKR TCS. In sum, HemKR responds to abundance of porphyrin metabolites by shutting down and controlling heme homeostasis, while also contributing to integrate the regulation of heme and iron metabolism in theL. biflexaspirochete model.
Effective biotechnology for reducing N2O-emissions from farmland: N2O-respiring bacteria vectored by organic waste
Authors: Hiis Elisabeth G , Vick Silas H W , Molstad Lars , Røsdal Kristine , Jonassen Kjell Rune , Winiwarter Wilfried , Bakken Lars R
Published: October 2023

Farmed soils contribute to global warming primarily by N2O-emissions, and mitigation has proven difficult. However, a novel approach with promising results in the laboratory, exploits organic wastes both as substrates and vectors for strains of N2O-respiring bacteria (NRB), selected for their ability to survive in soil. Here we demonstrate a strong effect in field experiments: fertilization with waste from biogas-production, in which the strainCloacibacteriumsp. CB-01 had grown aerobically to ∼6*109cells mL-1, reduced N2O-emissions by 50-95 %. The strong and long-lasting effect of CB-01 is ascribed to it’s tenacity in soil, rather than its biokinetic parameters, which were inferior to other NRB-strains. Scaling up to EU level, we find that national anthropogenic N2O-emissions can be reduced by 5-20 %, and more if including other organic wastes. This opens an avenue for cost-effective reduction of N2O-emissions for which other mitigation options are currently lacking.
A BAC-guided haplotype assembly pipeline increases the resolution of the virus resistance locusCMD2in cassava
Authors: Luc Cornet , Zaidi Syed Shan-e-Ali , Li Jia , Yvan Ngapout , Shakir Sara , Loic Meunier , Callot Caroline , Marande William , Marc Hanikenne , Rombauts Stephane , Van de Peer Yves , Vanderschuren Hervé
Published: October 2023

Cassava is an important crop for food security in the tropics where its production is jeopardized by several viral diseases, including the cassava mosaic disease (CMD) which is endemic in Sub-Saharan Africa and the Indian subcontinent. Resistance to CMD is linked to a single dominant locus, namelyCMD2. The cassava genome contains highly repetitive regions making the accurate assembly of a reference genome challenging. In the present study, we generated BAC libraries of the CMD– susceptible cassava cultivar (cv.) 60444 and the CMD–resistant landrace TME3. We subsequently identified and sequenced BACs belonging to theCMD2region in both cultivars using high-accuracy long-read PacBio circular consensus sequencing (ccs) reads. We then sequenced and assembled the complete genomes of cv. 60444 and TME3 using a combination of ONT ultra-long reads and optical mapping. Anchoring the assemblies on cassava genetic maps revealed discrepancies in our, as well as in previously released,CMD2regions of the cv. 60444 and TME3 genomes. A BAC guided approach to assess cassava genome assemblies significantly improved the synteny between the assembledCMD2regions of cv. 60444 and TME3 and theCMD2genetic maps. We then performed repeat-unmasked gene annotation onCMD2assemblies and identified 81 stress resistance proteins present in theCMD2region, amongst which 31 were previously not reported in publicly availableCMD2sequences.
Distinct function of Chlamydomonas CTRA-CTR transporters in Cu assimilation and intracellular mobilization
Authors: Strenkert Daniela , Schmollinger Stefan , Paruthiyil Srinand , Brown Bonnie C. , Green Sydnee , Shafer Catherine M. , Salomé Patrice , Nelson Hosea , Blaby-Haas Crysten E. , Moseley Jeffrey L. , Merchant Sabeeha S.
Published: October 2023

Successful acclimation to copper (Cu) deficiency involves a fine balance between Cu import and export. In the unicellular green algaChlamydomonas reinhardtii, Cu import is dependent onCopperResponseRegulator1(CRR1), the master regulator of Cu homeostasis. Among CRR1 target genes are two Cu transporters belonging to the CTR/COPT gene family (CTR1andCTR2) and a related soluble cysteine-rich protein (CTR3). The ancestor of these green algal proteins was likely acquired from an ancient chytrid and contained conserved cysteine-rich domains (named the CTR-associated domains, CTRA) that are predicted to be involved in Cu acquisition. We show by reverse genetics that Chlamydomonas CTR1 and CTR2 are canonical Cu importers albeit with distinct affinities, while loss of CTR3 did not result in an observable phenotype under the conditions tested. Mutation ofCTR1, but notCTR2, recapitulate the poor growth ofcrr1in Cu-deficient medium, consistent with a dominant role for CTR1 in high affinity Cu(I) uptake. Notably, the over-accumulation of Cu(I) in Zinc (Zn)-deficiency (20 times the quota) depends on CRR1 and both CTR1 and CTR2. CRR1-dependent activation ofCTRgene expression needed for Cu over-accumulation can be bypassed by the provision of excess Cu in the growth medium. Over-accumulated Cu is sequestered into the acidocalcisome but can become remobilized by restoring Zn nutrition. This mobilization is also CRR1-dependent, and requires activation ofCTR2expression, again distinguishing CTR2 from CTR1 and is consistent with the lower substrate affinity of CTR2.
Divergent spike mutations impact the activation of the fusion core in Delta and Omicron variants of SARS-CoV-2
Authors: Dutta Mandira , Voth Gregory A.
Published: October 2023

SARS-CoV-2 infects host cells by binding the receptor-binding domain (RBD) of its spike protein to the receptor, ACE2. A subset of highly effective spike mutations plays critical roles in altering the conformational dynamics of spike protein. Here, we use molecular dynamics simulations to investigate how spike mutations affect the conformational dynamics of spike/ACE2 complex in the D614G, Delta (B.1.617.2) and Omicron (B.1.1.529) SARS-CoV-2 variants. We observe that the increased positive-charged mutations in the Omicron spike amplify its structural rigidity and reduce its structural flexibility. The mutations (P681R in Delta and P681H in Omicron) at the S1/S2 junction facilitate S1/S2 cleavage and aid the activation of the fusion core. We report that high structural flexibility in Delta lowers the barrier for the activation of the S2 core; however, high structural rigidity in Omicron enhances the barrier for the same. Our results also explain why Omicron requires the presence of a higher number of ACE2 to activate its fusion core than Delta.
Relative vaccine effectiveness of a CoronaVac booster dose in preventing symptomatic SARS-CoV-2 infection among healthcare workers during an Omicron period in Azerbaijan, January–August 2022
Authors: Finci Iris , Rojas Castro Madelyn Yiseth , Seyidov Nabil , Mehdiyev Samir , McKnight C. Jason , Mühlemann Barbara , Drosten Christian , Duca Lindsey , Pebody Richard , Kissling Esther , Katz Mark A. , Hagverdiyev Gahraman
Published: October 2023

Among Azerbaijani healthcare workers (HCWs), compared to primary vaccine series, CoronaVac booster relative vaccine effectiveness was 60% (95% CI:25–79) and 79% (95% CI:44–92) against symptomatic and medically attended illness, respectively, during an Omicron BA.1/BA.2 period. Our results support timely CoronaVac booster uptake among Azerbaijani HCWs to reduce morbidity.
Triggers for Freezing of Gait in Individuals with Parkinson’s Disease: A Systematic Review
Authors: Conde Carolina I. , Lang Charlotte , Baumann Christian R. , Easthope Chris A. , Taylor William R. , Ravi Deepak K.
Published: October 2023

Background

Freezing of Gait (FOG) is a motor symptom frequently observed in advanced Parkinson’s disease. However, due to its paroxysmal nature and diverse presentation, assessing FOG in a clinical setting can be challenging. Before FOG can be fully investigated, it is critical that a reliable experimental setting is established in which FOG can be evoked in a standardised manner, but the efficacy of various gait tasks and triggers for eliciting FOG remains unclear.

Objectives

This study aimed to conduct a systematic review of the existing literature and evaluate the available evidence for the relationship between specific motor tasks, triggers, and FOG episodes in individuals with Parkinson’s disease (PwPD).

Methods

We conducted a literature search on four online databases (PubMed, Web of Science, EMBASE, and Cochrane Library) using the keywords “Parkinson’s disease,” “Freezing of Gait,” and “triggers.” A total of 128 articles met the inclusion criteria and were included in our analysis.

Results

The review found that a wide range of gait tasks were employed in gait assessment studies on PD patients. However, three tasks (turning, dual tasking, and straight walking) were the most frequently used. Turning (28%) appears to be the most effective trigger for eliciting FOG in PwPD, followed by walking through a doorway (14%) and dual tasking (10%).

Conclusions

This review thereby supports the use of turning especially 360 degrees as a reliable trigger for FOG in PwPD. This could be beneficial to clinicians during clinical evaluations and researchers who wish to assess FOG in a laboratory environment.
Biosynthesis of H-GDGTs linked to ocean oxygen deficiency
Authors: Li Yanan , Yu Ting , Feng Xi , Zhao Bo , Chen Huahui , Connock Gregory T. , Liu Xiao-Lei , Yang Huan , Kaiser Jérôme , Wittenborn Anna K. , Dong Liang , Wang Fengping , Anderson Hayden R. , Burns Noah Z. , Zeng Fuxing , Tao Lizhi , Zeng Zhirui
Published: October 2023

Archaeal membrane lipids GDGTs (glycerol dialkyl glycerol tetraethers) are biomarkers used for tracking Earth’s historical environmental changes. Among these GDGTs, the H-shaped GDGTs (H-GDGTs, or GMGTs) represent a less-explored and often overlooked subset, with its biosynthetic pathway and geological significance remaining elusive. Here, we identified the gene responsible for biosynthesizing H-GDGTs, which encodes to a radicalS-adenosyl-L-methionine (SAM) enzyme, named as H-GDGTs bridge synthase (Hbs). Heterologous expression of the genehbsin a methanogen, as well asin vitroactivity assay using the purified Hbs enzyme were performed. Additionally, we found that the genes encoding Hbs are exclusively present in obligate anaerobic archaea genomes and the metagenomes obtained from oxygen-deficient environments, but not in oxic settings. The H-GDGTs lipids were also consistently enriched in the modern oxygen-deficient environments, and remarkably accumulated in ancient sediments during oceanic anoxic event-2 (OAE-2, ∼94 million years ago) period. Our findings indicate H-GDGTs holds significant promise as a novel biomarker for studying historical ocean oxygen deficiency supported by a well-established biological basis.
Biofilms and core pathogens shape the tumour microenvironment and immune phenotype in colorectal cancer
Authors: Kvich Lasse , Fritz Blaine Gabriel , Zschach Henrike , Terkelsen Thilde , Raskov Hans , Høst-Rasmussen Kathrine , Jakobsen Morten Ragn , Gheorghe Alexandra Gabriella , Gögenur Ismail , Bjarnsholt Thomas
Published: October 2023

Objective

Growing evidence links bacterial dysbiosis with colorectal cancer (CRC) carcinogenesis, characterized by an increased presence of core pathogens such asBacteroides fragilisandFusobacterium nucleatum. Here, we characterized thein situbiogeography and transcriptional interactions between bacteria and the host in mucosal colon biopsies.

Design

The influence of CRC core pathogens and biofilms on the tumour microenvironment (TME) was investigated in biopsies from patients with and without CRC (paired normal tissue and healthy tissue biopsies) using fluorescencein situhybridization and dual-RNA sequencing.

Results

Tissue-invasive, mixed-species biofilms enriched forB. fragilisandF. nucleatumwere observed in CRC tissue, especially in right-sided tumours.Fusobacterium spp.was associated with increased bacterial biomass and inflammatory response in CRC samples. CRC samples with high bacterial activity demonstrated increased expression of pro-inflammatory cytokines, defensins, matrix-metalloproteases, and immunomodulatory factors. In contrast, the gene expression profiles of CRC samples with low bacterial activity resembled healthy tissue samples. Moreover, immune cell profiling showed thatB. fragilisandF. nucleatummodulated the TME and correlated with increased infiltration of neutrophils and CD4+T-cells. Overall, bacterial activity was critical for the immune phenotype and correlated with the infiltration of several immune cell subtypes, including M2 macrophages and regulatory T-cells.

Conclusion

Biofilms and core pathogens shape the TME and immune phenotype in CRC. Our results support thatFusobacterium spp. may provide a future therapeutic target to reduce biofilms and the inflammatory response in the TME while highlighting the importance of widening the scope of bacterial pathogenesis in CRC beyond core pathogens.
AutoEMage: automatic data transfer, preprocessing, real-time display and monitoring in cryo-EM
Authors: Cheng Yuanhao , Huang Xiaojun , Xu Bin , Ding Wei
Published: October 2023

Cryo-electron microscopy (cryo-EM), especially single-particle analysis, has become a powerful technique for visualizing the structure of biological macromolecules at high resolution. However, data acquisition in cryo-EM is time consuming because it requires the collection of thousands of images to achieve a high-quality reconstruction. Real-time preprocessing and display of the images can greatly enhance the efficiency and quality of data collection. This study presents AutoEMage, a new open-source software package that automates data transfer, preprocessing and real-time display in cryo-EM experiments. AutoEMage also includes a real-time data monitoring system that alerts users to issues with their data, allowing them to take corrective actions accordingly. The software is equipped with an easy-to-use graphical user interface that provides seamless data screening and real-time feedback on data quality and microscope status.
New features of the RootProf program for model-free analysis of unidimensional profiles
Authors: Mazzone Annamaria , Lopresti Mattia , Belviso Benny Danilo , Caliandro Rocco
Published: October 2023

The RootProf computer program applies multivariate model-free analysis to crystallographic data and to any x, y experimental data in general. It has been enhanced with several new features, including a graphical user interface, multithreading implementation and additional pre-processing options. The program also includes novel qualitative analysis methods, such as semiquantitative estimates derived from principal component analysis (PCA) and restrained PCA to extract the diffraction signal from active atoms. Additional quantitative analysis methods have been included, involving the combination of different datasets or the application of the standard addition method as well as tools for crystallinity analysis, kinetic analysis and extraction of free crystal cell parameters from a pair distribution function profile. The ROOT data analysis framework supports the program and can be installed on the current major platforms such as Windows, Linux and Mac OSX with detailed user documentation included. Applications of the new developments are presented and discussed in the paper, and related command files are provided as supporting information.
Domain structure and cross-linking in a giant adhesin from the Mobiluncus mulieris bacterium
Authors: Young Paul G. , Paynter Jacob M. , Wardega Julia K. , Middleditch Martin J. , Payne Leo S. , Baker Edward N. , Squire Christopher J.
Published: October 2023

Cell-surface proteins known as adhesins enable bacteria to colonize particular environments, and in Gram-positive bacteria often contain autocatalytically formed covalent intramolecular cross-links. While investigating the prevalence of such cross-links, a remarkable example was discovered in Mobiluncus mulieris, a pathogen associated with bacterial vaginosis. This organism encodes a putative adhesin of 7651 residues. Crystallography and mass spectrometry of two selected domains, and AlphaFold structure prediction of the remainder of the protein, were used to show that this adhesin belongs to the family of thioester, isopeptide and ester-bond-containing proteins (TIE proteins). It has an N-terminal domain homologous to thioester adhesion domains, followed by 51 immunoglobulin (Ig)-like domains containing ester- or isopeptide-bond cross-links. The energetic cost to the M. mulieris bacterium in retaining such a large adhesin as a single gene or protein construct suggests a critical role in pathogenicity and/or persistence.
The impact of molecular variants, crystallization conditions and the space group on ligand–protein complexes: a case study on bacterial phosphotriesterase
Authors: Dym Orly , Aggarwal Nidhi , Ashani Yacov , Leader Haim , Albeck Shira , Unger Tamar , Hamer-Rogotner Shelly , Silman Israel , Tawfik Dan S. , Sussman Joel L.
Published: October 2023

A bacterial phosphotriesterase was employed as an experimental paradigm to examine the effects of multiple factors, such as the molecular constructs, the ligands used during protein expression and purification, the crystallization conditions and the space group, on the visualization of molecular complexes of ligands with a target enzyme. In this case, the ligands used were organophosphates that are fragments of the nerve agents and insecticides on which the enzyme acts as a bioscavenger. 12 crystal structures of various phosphotriesterase constructs obtained by directed evolution were analyzed, with resolutions of up to 1.38 Å. Both apo forms and holo forms, complexed with the organophosphate ligands, were studied. Crystals obtained from three different crystallization conditions, crystallized in four space groups, with and without N-terminal tags, were utilized to investigate the impact of these factors on visualizing the organophosphate complexes of the enzyme. The study revealed that the tags used for protein expression can lodge in the active site and hinder ligand binding. Furthermore, the space group in which the protein crystallizes can significantly impact the visualization of bound ligands. It was also observed that the crystallization precipitants can compete with, and even preclude, ligand binding, leading to false positives or to the incorrect identification of lead drug candidates. One of the co-crystallization conditions enabled the definition of the spaces that accommodate the substituents attached to the P atom of several products of organophosphate substrates after detachment of the leaving group. The crystal structures of the complexes of phosphotriesterase with the organophosphate products reveal similar short interaction distances of the two partially charged O atoms of the P—O bonds with the exposed β-Zn2+ ion and the buried α-Zn2+ ion. This suggests that both Zn2+ ions have a role in stabilizing the transition state for substrate hydrolysis. Overall, this study provides valuable insights into the challenges and considerations involved in studying the crystal structures of ligand–protein complexes, highlighting the importance of careful experimental design and rigorous data analysis in ensuring the accuracy and reliability of the resulting phosphotriesterase–organophosphate structures.
Optimizing energy retrofitting of existing buildings through combinations of advanced noninvasive interventions: a case study in a hot climate zone
Authors: Reffat Rabee , Adel Julia
Published: October 2023

Purpose

This purpose of this paper is to address the problem of reducing energy consumption in existing buildings using advanced noninvasive interventions (NVIs).

Design/methodology/approach

The study methodology involves systematically developing and testing 18 different NVIs in six categories (glazing types, window films, external shading devices, automated internal shades, lighting systems and nanopainting) to identify the most effective individual NVIs. The impact of each individual NVI was examined on an exemplary university educational building in a hot climate zone in Egypt using a computational energy simulation tool, and the results were used to develop 39 combination scenarios of dual, triple and quadruple combinations of NVIs.

Findings

The optimal 10 combination scenarios of NVIs were determined based on achieving the highest percentages of energy reduction. The optimal percentage of energy reduction is 47.1%, and it was obtained from a combination of nanowindow film, nanopainting, LED lighting and horizontal louver external. The study found that appropriate mixture of NVIs is the most key factor in achieving the highest percentages of energy reduction.

Practical implications

These results have important implications for optimizing energy savings in existing buildings. The results can guide architects, owners and policymakers in selecting the most appropriate interventions in existing buildings to achieve the optimal reduction in energy consumption.

Originality/value

The novelty of this research unfolds in two significant ways: first, through the exploration of the potential effects arising from the integration of advanced NVIs into existing building facades. Second, it lies in the systematic development of a series of scenarios that amalgamate these NVIs, thereby pinpointing the most efficient strategies to optimize energy savings, all without necessitating any disruptive alterations to the existing building structure. These combination scenarios encompass the incorporation of both passive and active NVIs. The potential application of these diverse scenarios to a real-life case study is presented to underscore the substantial impact that these advanced NVIs can have on the energy performance of the building.
Human resources practices as a moderator for inculcating lean thinking in IT organizations – an empirical approach
Authors: Megha B. , Srikantha Dath T.N.
Published: October 2023

Purpose

Human Resource Practices (HRPs) have undergone a revolutionary change, with their practices being more strategic for facilitating the change process. Extant literature studies the impact of Lean Thinking Practices (LTPs) on Organizational Performance (OP). However, the role of HRP as a strategic partner in the inculcation of LTP appears to have been explored sparingly. Hence, this paper aims to identify the specific HRPs that enhance the impact of Lean Thinking on OP.

Design/methodology/approach

A cross-sectional survey method was adopted. A total of 528 responses from IT organizations across various levels and processes were collected. The proposed conceptual framework was tested and validated SPSS-Process Macro.

Findings

Findings revealed that the presence of HRPs as moderators is significantly impacting the relationship between LTP and OP. LTP when moderated by HRPs significantly impacts employee well-being when compared to other performance variables.

Originality/value

This study is a maiden attempt to study the role of HRP in the inculcation of LTP in IT organizations. Earlier studies, which have mainly concentrated on the need for Human Resource (people) involvement, have spoken and researched less about the specific HRPs in the inculcation of LTP. An empirically validated specific HRP for inculcating LTP in IT organizations is a significant contribution.
Are leaders born or made? Asking the right question.
Authors: Sposato Martin
Published: October 2023

Purpose

The current viewpoint addressed the old debate on whether leaders are born or made and argues that both perspectives are relevant and that leaders are a combination of both.

Design/methodology/approach

Based on personal experience working and researching leadership development this viewpoint argues for the need to understand that both leaders are born but they need to be developed.

Findings

The article provides arguments for the synergy that exist between the view that leaders are made and the view that argues that leaders are born.

Originality/value

From an originality perspective the article attempts to build a bridge between the ideas that leaders are born or made by focusing on the synergies of both camps.
Three-dimensional slope stability and anti-slide pile treatment of Zhangjiayao landslide under rainfall
Authors: Han Chen-Xi , Hou Tian-Shun , Chen Ye
Published: October 2023

Purpose

To solve the instability problem of Zhangjiayao landslide caused by rainfall, the internal mechanism of slope instability and the supporting effect of anti-slide piles are studied. The research results can provide theoretical basis for the prevention and control of loess landslides.

Design/methodology/approach

A three-dimensional finite element model of Zhangjiayao landslide is established by field geological survey, laboratory test and numerical simulation.

Findings

The results show that Zhangjiayao landslide is a loess-mudstone contact surface landslide, and rainfall leads to slope instability and traction landslide. The greater the rainfall intensity, the faster the pore water pressure of the slope increases and the faster the matrix suction decreases. The longer the rainfall duration, the greater the pore water pressure of the slope and the smaller the matrix suction. Anti-slide pile treatment can significantly improve slope stability. The slope safety factor increases with the increase of embedded depth of anti-slide pile and decreases with the increase of pile spacing.

Originality/value

Based on the unsaturated soil seepage theory and finite element strength reduction method, the failure mechanism of Zhangjiayao landslide was revealed, and the anti-slide pile structure was optimized and designed based on the pile-soil interaction principle. The research results can provide theoretical basis for the treatment of loess landslides.

Highlights

A three-dimensional finite element model of Zhangjiayao landslide is established.

Zhangjiayao landslide is a loess-mudstone contact surface landslide.

The toe of Zhangjiayao slope is first damaged by heavy rainfall, resulting in traction landslide.

The deformation of Zhangjiayao slope is highly dependent on rainfall intensity and duration.

The anti-slide pile can effectively control the continuous sliding of Zhangjiayao slope.
The impact of emotional labor strategy order effects on customer satisfaction within service episodes
Authors: Groth Markus , Esmaeilikia Mahsa
Published: October 2023

Purpose

This paper aims to aims to extend emotional labor research by exploring whether the impact of emotional labor on customer satisfaction depends on the order in which different emotional labor strategies are used by employees. Specifically, the authors explore how the order effects of two emotional labor strategies – deep and surface acting – impact customer satisfaction.

Design/methodology/approach

The authors conducted two experimental studies in which participants interacted with service employees who systematically switched between surface and deep acting strategies during the service episode. In Study 1, participants watched a video clip depicting a service encounter in a bookstore. In Study 2, participants partook in a simulated career-counseling session.

Findings

The four different emotional labor strategy order effects differentially impact customer satisfaction. Consistent with theories of gain–loss effects, improvement and decline trends positively or negatively impact customers, respectively. Furthermore, results show that these trends impact customer satisfaction growth differently over time.

Research limitations/implications

The authors only focused on two emotional labor strategies, and future research may benefit from extending the research to additional regulation strategies and/or specific discrete emotions.

Practical implications

The results suggest that managers may train employees in recognizing that customer satisfaction is not just driven by customers’ overall assessment of the interaction but also by their experience at different stages of the interaction.

Originality/value

Service marketing and management scholars have largely explored emotional labor from a between-person or within-person perspective, with little empirical attention paid to within-episode processes that focus on how employee behavior varies within a single service episode. To the best of the authors’ knowledge, this study is one of the first to demonstrate that surface and deep acting can be used simultaneously and dynamically over the course of a single service interaction in impacting customer satisfaction.
Parental international migration and health of children left-behind: evidence from an Asian economy
Authors: Zafar Sameen
Published: October 2023

Purpose

There is a considerable gap in the literature examining the effect of parental international migration on children’s health in Pakistan. The author aims to examine the impact of parental international labour migration on the health (anthropometric measures) of children left-behind in Pakistan.

Design/methodology/approach

The author investigates the impact of parental international labour migration on the health (anthropometric measures) of children left-behind in Pakistan using econometric estimation techniques and the latest wave of the Pakistan Demographic and Health Survey 2017–2018. The main child health measures the author uses include weight-for-age (WAZ) and height-for-age (HAZ) Z-scores for children under five years of age. Since unobservable factors may be vital determinants of the child nutrition outcomes, the author uses two unique instrumental variables to address the potential endogeneity problem.

Findings

The author finds that international migration improves the left-behind children’s weight-for-age and height-for-age nutritional outcomes, generating essential policy insights.

Originality/value

To the best of the auhtor’s knowledge, no previous study has been conducted on parental migration and left-behind children in Pakistan using the latest Demographic and Health Survey.
Transgenerational value transmission in business-owning families: an indigenous African perspective
Authors: Kupangwa Welcome , Farrington Shelley Maeva , Venter Elmarie
Published: October 2023

Purpose

This study aims to investigate the favourable conditions that influence transgenerational value transmission (TVT), value acceptance and value similarity between generations in indigenous African business-owning families.

Design/methodology/approach

This study adopts a multiple case study design and draws on semi-structured face-to-face interviews to collect data from participants in seven indigenous Black business-owning families located in South Africa. The software ATLAS.ti was utilised to manage the data and reflexive thematic analysis was undertaken.

Findings

The analysis reveal four themes describing how transmission factors facilitate favourable conditions for successful TVT in IBSA business-owning families, namely, authoritarian parenting, a loving and connected family relational climate, the continuous reinforcement of autonomy during childhood development and family authenticity in the face of societies dominant values climate. Furthermore, value similarity is perceived to exist among the different family generations in the business-owning families.

Originality/value

This study is among the first to adopt the value acquisition model to empirically examine successful TVT and examine the extent of value similarity or dissimilarity, using the business-owning family as the unit of analysis. Novel contributions to family business literature and practices are proposing a model for TVT in an African context and studying relationships from a business-owning family perspective. The model for TVT could be used to socialise the NextGen members into value sets and behaviours that help business-owning families preserve their entrepreneurial legacy and family business longevity.
Learning from family business researchers
Authors: Ratten Vanessa , Chrisman James J. , Mustafa Michael , Sciascia Salvatore , Seaman Claire , Discua Cruz Allan , Feranita Feranita
Published: October 2023

Purpose

This article provides commentary from well-known family business researchers on what they have learnt about the family business field and tips for the future.

Design/methodology/approach

Well-known family business management researchers were contacted in order to provide their feedback on the field of family business management. Their responses were then curated into an article that can help others learn from their advice.

Findings

The family business management researchers provided suggestions on how to succeed in the field of family business management and advice for current and future researchers. Thereby helping to advance the field and provide new novel research ideas that can help science as well as practice.

Originality/value

This article is amongst the first to provide verbatim advice from the leading family business management scholars. Thus, providing original and innovative ideas about what is needed in the field of family business management.
Records in social media: a new (old) understanding of records management
Authors: Oladejo Babatunde Kazeem , Hofman Darra
Published: October 2023

Purpose

Social media posts have been an integral part of our society’s communication and serve purposes from the personal to the national, from the mundane to the silly to the momentous. This study aims to examine social media posts as records, discussing how social media technology serves, perhaps unexpectedly, to reinforce traditional archival understandings of issues such as provenance, custody, access, disposition and preservation.

Design/methodology/approach

This study follows a four-step methodology. First, this study analyzes literature for a matching definition of the social media record. In the second step, we appraise three social media postings previously curated and cited in news articles by journalists to determine their characteristics – Are these social media posts “records?” Third, this study evaluates the sample records against two dominant theoretical record models, the life cycle and the continuum and attempt to apply the model specifications to the data samples. Finally, this study proposes appropriate records management solutions to address governance issues from the study findings in the conclusion section.

Findings

This study shows that, even by the most traditional of definitions, social media posts are records. The paper also demonstrates that platform mediation transforms simple narrative documents into records whose provenance, custody and control are dictated by platform logics and governance, outside of the control of their creators. Through appraisal of a small sample of “important” social media posts, this study illustrates that, rather than obsolete, traditional records management concepts and approaches are necessary to ensuring the ongoing accessibility, usability and evidentiary character of social media posts in the broader “platformized” context.

Research limitations/implications

This is exploratory, theoretical work. In future works, this study plans to expand and validate aspects of this study.

Originality/value

This paper tests existing theoretical frameworks, namely, the Records Life cycle and the Records Continuum for applicability to the social media record. The paper also offers a view of the potential for traditional archival and records management concepts in service of a just and inclusive recordkeeping, because such concepts allow us to demonstrate the centralized, elite-serving, bureaucratic structures which underpin social media records are obscured by the seemingly decentralized, participatory nature of social media.
Images’ features and Airbnb listing price: the mediation effect of visual aesthetic perception
Authors: Hu Mingming , Lin Lijing , Liu Minkun , Ma Shuai
Published: October 2023

Purpose

This study aims to explore image-based visual price determinants (image features and visual aesthetic perception) and how image features affect Airbnb listing price on a sharing accommodation platform.

Design/methodology/approach

The study uses an SOR model and a hedonic price model to examine the connections between the characteristics of image features, visual aesthetic perception and Airbnb listing prices. The model is then examined by an econometric model using data from Insideairbnb.com.

Findings

Empirical results revealed that image features have a significant positive effect on visual aesthetic perception, visual aesthetic perception has a significant positive effect on Airbnb listing price and visual aesthetic perception has a significant mediating effect between image features and Airbnb listing price.

Originality/value

This study contributes to the relationship and effect mechanism among image features, visual aesthetic perception and Airbnb listing price and has some implications for both property operators and the sharing accommodation platform.