bluuebunny/crossref_metadata_2025 huggingface dataset:
Cola Subgenus Disticha subg. nov. (Malvaceae-Sterculiaceae) of tropical Africa, a synoptic taxonomic revision with seven new species
Authors: Cheek Martin
Published: August 2022

A new subgenus, Subg. Disticha is erected for 14 species of simple-leaved Cola sharing unique characters within the genus which are presumed synapomorphies: distichous phyllotaxy; petioles lacking pulvini; petioles of uniformly short length, <10 mm long; male flowers with short androphores <1(– 2) mm long; stamens 4 – 5; stem indumentum where present, dominated by short simple translucent hairs (except in C. philipi-jonesii where stellate), and in many species dark purple to black stems with contrasting bright white lenticels. All species have fruit with small globose, unsculptured orange mericarps c. 1 cm diam. (where fruits are known). The species of this subgenus range from SE Nigeria in the west to coastal Kenya and Tanzania in the east and Malawi in the south, but are absent from the Congo basin. Species diversity is highest in the Cross-Sanaga and Eastern Arc-Coastal Forest biogeographic areas, consistent with these taxa being Pleistocene refuge species. The species are mainly monoecious, but dioecy cannot yet be ruled out in some species. In two species where sufficient material was available for investigation (Cola chlorantha, C. roy), the simple cymes were found to be bisexual, the terminal flower being female, the two lateral flowers often being male, a pattern previously unreported in the genus. All species are understorey shrubs or small trees of evergreen lowland or submontane forest, except C. uloloma of coastal semi-deciduous forest in E Africa and which is unique in showing xerophilic characteristics. The species can be divided into group A: five species mainly in E Africa with rapidly glabrescent or glabrous stems, conspicuously asymmetric leaves, few-flowered, pedunculate cymes (C. uloloma, C. chlorantha, C. roy sp.nov., C.”udzungwa”, C. asymmetrica sp. nov.); group B: in Lower Guinea (Atlantic coast of Africa) with hairy stems, symmetric or inconspicuously asymmetric leaves, sessile, fasciculate inflorescences: (Cola mayimbensis, C. philipi-jonesii, C. metallica, C.moussavoui, C. stigmatosa, C. takamanda sp.nov. C. toyota sp. nov, C. “campo-ma’an”, C. zanaga sp. nov.). Of the seven new species to science, two are named informally since the material is so incomplete (sterile), and five are formally named. Species diversity is highest in Cameroon and Tanzania, each with four species, followed by Gabon with three species. It is expected that additional new species will be found in poorly-surveyed surviving evergreen forest habitat in each of these three countries. Conservation assessments are given for each species using the IUCN 2012 standard. All species are considered threatened, with ten species being Critically Endangered (the highest category of threat), each known from a single location, with their forest habitat threatened mainly by clearance for agriculture.
Are Deep Learning Structural Models Sufficiently Accurate for Free Energy Calculations? Application of FEP+ to AlphaFold2 Predicted Structures
Authors: Beuming Thijs , Martín Helena , Díaz-Rovira Anna M. , Díaz Lucía , Guallar Victor , Ray Soumya S.
Published: August 2022

The availability of AlphaFold2 has led to great excitement in the scientific community - particularly among drug hunters - due to the ability of the algorithm to predict protein structures with high accuracy. However, beyond globally accurate protein structure prediction, it remains to be determined whether ligand binding sites are predicted with sufficient accuracy in these structures to be useful in supporting computationally driven drug discovery programs. We explored this question by performing free energy perturbation (FEP) calculations on a set of well-studied protein-ligand complexes, where AlphaFold2 predictions were performed by removing all templates with >30% identity to the target protein from the training set. We observed that in most cases, the ΔΔG values for ligand transformations calculated with FEP, using these prospective AlphaFold2 structures, were comparable in accuracy to the corresponding calculations previously carried out using X-ray structures. We conclude that under the right circumstances, AlphaFold2 modeled structures are accurate enough to be used by physics-based methods such as FEP, in typical lead optimization stages of a drug discovery program.
Large-scale network metrics improve the classification performance of rapid-eye-movement sleep behavior disorder patients
Authors: Roascio Monica , Turrisi Rosanna , Arnaldi Dario , Famà Francesco , Mattioli Pietro , Nobili Flavio , Barla Annalisa , Arnulfo Gabriele
Published: August 2022

Clinical decision support systems based on machine-learning algorithms are largely applied in the context of the diagnosis of neurodegenerative diseases (NDDs). While recent models yield robust classifications in supervised two classes-problems accurately separating Parkinson’s disease (PD) from healthy control (HC) subjects, few works looked at prodromal stages of NDDs. Idiopathic Rapid-eye Movement (REM) sleep behavior disorder (iRBD) is considered a prodromal stage of PD with a high chance of phenoconversion but with heterogeneous symptoms that hinder accurate disease prediction. Machine learning (ML) based methods can be used to develop personalized trajectory models, but these require large amounts of observational points with homogenous features significantly reducing the possible imaging modalities to non-invasive and cost-effective techniques such as high-density electrophysiology (hdEEG). In this work, we aimed at quantifying the increase in accuracy and robustness of the classification model with the inclusion of network-based metrics compared to the classical Fourier-based power spectral density (PSD). We performed a series of analyses to quantify significance in cohort-wise metrics, the performance of classification tasks, and the effect of feature selection on model accuracy.

We report that amplitude correlation spectral profiles show the largest difference between iRBD and HC subjects mainly in delta and theta bands. Moreover, the inclusion of amplitude correlation and phase synchronization improves the classification performance by up to 11% compared to using PSD alone. Our results show that hdEEG features alone can be used as potential biomarkers in classification problems using iRBD data and that large-scale network metrics improve the performance of the model. This evidence suggests that large-scale brain network metrics should be considered important tools for investigating prodromal stages of NDD as they yield more information without harming the patient, allowing for constant and frequent longitudinal evaluation of patients at high risk of phenoconversion.

Highlights

Network-based features are important tools to investigate prodromal stages of PD

Amplitude correlation shows the largest difference between two groups in 9/30 bands

Amplitude correlation improved up to 11% the performance compared to PSD alone

Classification robustness increases when we use both network-based EEG features

Classifier performance worsens when PSD is added to network-based EEG features
ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
Authors: Olivas Taryn J. , Wu Yumei , Yu Shenliang , Luan Lin , Choi Peter , Nag Shanta , De Camilli Pietro , Gupta Kallol , Melia Thomas J.
Published: August 2022

During autophagosome biogenesis, the incorporation of transmembrane proteins into the expanding phagophore is not readily observed. In addition, the membrane surface area of the organelle expands rapidly, while the volume of the autophagosome is kept low. Several recent studies have suggested a model of membrane expansion that explains how these attributes are maintained. The autophagosome expands predominantly through the direct protein-mediated transfer of lipids through the lipid transfer protein ATG2. As these lipids are only introduced into the cytoplasmic-facing leaflet of the expanding phagophore, full membrane growth also requires lipid scramblase activity. ATG9 has been demonstrated to harbor scramblase activity and is essential to autophagosome formation, however if and when it is integrated into mammalian autophagosomes remains unclear. Here we show that in the absence of lipid transport, ATG9 vesicles are already fully competent to collect proteins normally found on mature autophagosomes, including LC3-II. Further, through the novel use of styrene-maleic acid lipid particles as a nanoscale interrogation of protein organization on intact membranes, we show that ATG9 is fully integrated in the same membranes as LC3-II, even on maturing autophagosomes. The ratios of these two proteins at different stages of maturation demonstrate that ATG9 proteins are not continuously integrated, but rather are present on the seed vesicles only and become diluted in the rapidly expanding autophagosome membrane. Thus, ATG9 vesicles are the seed membrane from which mammalian autophagosomes form.
Spatial confinement modulates macrophage response in microporous annealed particle (MAP) scaffolds
Authors: Liu Yining , Suarez-Arnedo Alejandra , Riley Lindsay , Miley Tasman , Xia Jingyi , Segura Tatiana
Published: August 2022

Macrophages are essential in the initiation, maintenance, and transition of inflammatory processes like foreign body response and wound healing. Mounting evidence suggests that physical factors also modulate macrophage activationin vitroandin vivo. 2Din vitrosystems have demonstrated that constraining macrophages to small areas or channels modulates their phenotypes and changes their responses to known inflammatory agents such as lipopolysaccharide. However, how dimensionality and pore size affect macrophage phenotype is less explored. In this work, we studied the change in M1/M2 polarization when macrophages were confined in microporous annealed particle scaffolds (MAP), which are granular hydrogels generated from annealed spherical microgels. We engineered three types of MAP gels comprising 40, 70, and 130 µm diameter particle sizes, respectively. Particles sizes were selected using outputs from software LOVAMAP that analyzes the characteristics of 3-D pores in MAP gels. Since the size of building block particle correlates with pore size inside the final scaffolds, our three scaffold types allowed us to study how the degree of spatial confinement modulated the behavior of embedded macrophages. Spatially confining macrophages in scaffolds with pore size on the scale of cells led to a reduced level of the inflammatory response, which was correlated with a change in cell morphology and motility.
The bed nucleus of the stria terminalis mediates the expression of proactive defensive behavior
Authors: Guerra Diana P. , Wang Wei , de Souza Karienn A. , Moscarello Justin M.
Published: August 2022

The bed nucleus of the stria terminalis (BNST) is a forebrain region implicated in aversive responses to uncertain threat. Much of the work on the role of BNST in defensive behavior has used Pavlovian paradigms in which the subject reacts to aversive stimuli delivered in a pattern determined entirely by the experimenter. Here, we report that BNST also mediates proactive defensive responses in a task that allows subjects to prevent the delivery of an aversive outcome. In a standard two-way signaled active avoidance paradigm, male rats learned to shuttle during a tone to avoid shock. Our data demonstrate that chemogenetic inhibition (hM4Di) of BNST attenuates the expression of the avoidance response, whereas chemogenetic activation (hM3Dq) of BNST potentiates the response by extending the period of tone-evoked shuttling. This effect was specific to the BNST, as inactivation of the neighboring medial septum produced no effect on the expression of avoidance. These data support the novel conclusion that BNST mediates two-way avoidance behavior in male rats.
RNA localization to the mitotic spindle regulated by kinesin-1 and dynein is essential for early development of the sea urchin embryo
Authors: Remsburg Carolyn M. , Konrad Kalin D. , Song Jia L.
Published: August 2022

Mitosis is a fundamental and highly regulated process that acts to faithfully segregate chromosomes into two identical daughter cells. Transcript localization of genes involved in mitosis to the mitotic spindle may be an evolutionarily conserved mechanism to ensure that mitosis occurs in a timely manner. We identified many RNA transcripts that encode proteins involved in mitosis localized at the mitotic spindles in dividing sea urchin embryos and mammalian cells. Disruption of microtubule polymerization, kinesin-1, or dynein results in lack of spindle localization of these transcripts in the sea urchin embryo. Further, results indicate that the cytoplasmic polyadenylation element (CPE) within the 3’UTR of Aurora B, a recognition sequence of CPEB, is essential for RNA localization to the mitotic spindle. Blocking this sequence results in arrested development during early cleavage stages, suggesting that RNA localization to the mitotic spindle may be a regulatory mechanism of cell division that is important for early development.
Nanosecond pulsed electric field ablates rabbit VX2 liver tumors in a non-thermal manner versus radiofrequency ablation
Authors: Li Qing-Gang , Liu Zhen-Guo , Sun Ying , Zou Ya-Wen , Chen Xiao-Long , Wu Bin , Chen Xin-Hua , Ren Zhi-Gang
Published: August 2022

Background

Liver tumor remains an important cause of cancer-related death. Nanosecond pulsed electric fields (nsPEFs) are advantageous in the treatment of melanoma and pancreatic cancer, but their therapeutic application on liver tumors need to be further studied.

Methods

Hep3B cells were treated with nsPEFs. The biological behaviors of cells were detected by Cell Counting Kit-8, 5-ethynyl-20-deoxyuridine, and transmission electron microscopy (TEM) assays. In vivo, rabbit VX2 liver tumor models were ablated by ultrasound-guided nsPEFs and radiofrequency ablation (RFA). Contrast-enhanced ultrasound (CEUS) was used to evaluate the ablation effect. HE staining and Masson staining were used to evaluate the tissue morphology after ablation. Immunohistochemistry was performed to determine the expression of Ki67, proliferating cell nuclear antigen, and α-smooth muscle actin at different time points after ablation.

Results

The cell viability of Hep3B cells was continuously lower than that of the control group within 3 days after pulse treatment. The proliferation of Hep3B cells was significantly affected by nsPEFs. TEM showed that Hep3B cells underwent significant morphological changes after pulse treatment. In vivo, CEUS imaging showed that nsPEFs could completely ablate model rabbit VX2 liver tumors. After nsPEFs ablation, the area of tumor fibrosis and the expression of Ki67, proliferating cell nuclear antigen, and α-smooth muscle actin were decreased. However, after RFA, rabbit VX2 liver tumor tissue showed complete necrosis, but the expression of PCNA and α-smooth muscle actin did not decrease compared to the tumor group.

Conclusions

nsPEFs can induce Hep3B cells apoptosis and ablate rabbit VX2 liver tumors in a non-thermal manner versus RFA. The ultrasound contrast agent can monitor immediate effect of nsPEF ablation. This study provides a basis for the clinical study of nsPEFs ablation of liver cancer.
Experience-dependent plasticity of gustatory insular cortex circuits and taste preferences
Authors: Schiff Hillary C. , Kogan Joshua F. , Isaac Maria , Czarnecki Lindsey A. , Fontanini Alfredo , Maffei Arianna
Published: August 2022

Early experience with food influences taste preference in adulthood. How gustatory experience influences development of taste preferences and refinement of cortical circuits has not been investigated. Here we exposed weanling mice to an array of tastants and determined the effects on the preference for sweet in adulthood. We demonstrate an experience-dependent shift in sucrose preference persisting several weeks following the termination of exposure. A shift in sucrose palatability, altered neural responsiveness to sucrose, and inhibitory synaptic plasticity in the gustatory portion of the insular cortex (GC) were also induced. The modulation of sweet preference occurred within a restricted developmental window, but restoration of the capacity for inhibitory plasticity in adult GC reactivated the sensitivity of sucrose preference to taste experience. Our results establish a fundamental link between gustatory experience, sweet-preference, inhibitory plasticity, and cortical circuit function, and highlight the importance of early life experience in setting taste preferences.
Novel gene-intergenic fusion involving ubiquitin E3 ligase UBE3C causes distal hereditary motor neuropathy: A new mechanism for motor neuron degeneration
Authors: Cutrupi Anthony N. , Narayanan Ramesh K. , Perez-Siles Gonzalo , Grosz Bianca R. , Lai Kaitao , Boyling Alexandra , Ellis Melina , Lin Ruby CY , Neumann Brent , Mao Di , Uesugi Motonari , Nicholson Garth A. , Vucic Steve , Saporta Mario A. , Kennerson Marina L.
Published: August 2022

Distal hereditary motor neuropathies (dHMNs) are a group of inherited diseases involving the progressive, length-dependent axonal degeneration of the lower motor neurons. There are currently 29 reported causative genes and 4 disease loci implicated in dHMN. Despite the high genetic heterogeneity, mutations in the known genes account for less than 20% of dHMN cases with the mutations identified predominantly being point mutations or indels. We have expanded the spectrum of dHMN mutations with the identification of a 1.35 Mb complex structural variation (SV) causing a form of autosomal dominant dHMN (DHMN1 OMIM %182906). Given the complex nature of SV mutations and the importance of studying pathogenic mechanisms in a neuronal setting, we generated a patient-derived DHMN1 motor neuron model harbouring the 1.35 Mb complex insertion. The DHMN1 complex insertion creates a duplicated copy of the first 10 exons of the ubiquitin-protein E3 ligase gene (UBE3C) and forms a novel gene-intergenic fusion sense transcript by incorporating a terminal pseudo-exon from intergenic sequence within the DHMN1 locus. The UBE3C intergenic fusion (UBE3C-IF) transcript does not undergo nonsense-mediated decay and results in a significant reduction of wild type full length UBE3C (UBE3C-WT) protein levels in DHMN1 iPSC-derived motor neurons. An engineered transgenic C. elegans model expressing the UBE3C-IF transcript in GABA-ergic motor neurons shows neuronal synaptic transmission deficits. Furthermore, the transgenic animals are susceptible to heat stress which may implicate defective protein homeostasis underlying DHMN1 pathogenesis. Identification of the novel UBE3C-IF gene-intergenic fusion transcript in motor neurons highlights a potential new disease mechanism underlying axonal and motor neuron degeneration. These complementary models serve as a powerful paradigm for studying the DHMN1 complex SV and an invaluable tool for defining therapeutic targets for DHMN1.
Reshuffling of the coral microbiome during dormancy
Authors: Brown Anya L , Sharp Koty , Apprill Amy
Published: August 2022

Quiescence, or dormancy, is a response to stressful conditions in which an organism slows or halts physiological functioning. Although most species that undergo dormancy maintain complex microbiomes, there is little known about how dormancy influences and is influenced by the host’s microbiome, including in the temperate coral, Astrangia poculata. Northern populations of A. poculata undergo winter quiescence. Here, we characterized wild A. poculata microbiomes in a high-resolution sampling time series before, during, and after quiescence using 16S ribosomal RNA gene sequencing on active (RNA) and present (DNA) microbiomes. We observed a restructuring of the coral microbiome during quiescence that persisted after re-emergence. Upon entering quiescence, corals shed copiotrophic microbes, including putative pathogens, suggesting removal of these taxa as corals cease normal functioning. During and after quiescence, bacteria and archaea associated with nitrification were enriched, suggesting the quiescent microbiome may replace essential functions through supplying nitrate to corals and/or microbes. Overall, this study demonstrates that key microbial groups related to quiescence in A. poculata may play a role in the onset or emergence from dormancy, and long-term regulation of the microbiome composition. The predictability of dormancy in A. poculata provides an ideal natural manipulation system to further identify factors that regulate host-microbial associations.

Importance

Using a high-resolution sampling time series, we are the first to demonstrate a persistent microbial community shift with quiescence (dormancy) in a marine organism, the temperate coral, Astrangia poculata. Furthermore, during this period of community turnover, there is a shedding of putative pathogens and copiotrophs and an enhancement of the ammonia-oxidizing bacteria (Nitrosococcales) and archaea (Ca. Nitrosopumilus). Our results suggest that quiescence represents an important period during which the coral microbiome can “reset,” shedding opportunistic microbes and enriching for the re-establishment of beneficial associates, including those that may contribute nitrate while the coral animal is not actively feeding. We suggest this work provides foundational understanding of the interplay of microbes and the host’s dormancy response in marine organisms.
Dopaminergic neurons dynamically update sensory values during navigation
Authors: Kato Ayaka , Ohta Kazumi , Okanoya Kazuo , Kazama Hokto
Published: August 2022

Updating the value of sensory cues through experiences is a critical element of adaptive behavior. Although dopaminergic neurons (DANs) achieve this by driving associative learning, whether they contribute to assessment of sensory values outside the context of association remains largely unexplored. Here we show in Drosophila that DANs in the mushroom body encode the innate value of odors and constantly update the current value by inducing plasticity during olfactory navigation. Simulation of neuronal activity in a network based on the connectome data reproduced the characteristics of DAN responses, proposing a concrete circuit mechanism for computation. Notably, odors alone induced value- and dopamine-dependent changes in the activity of mushroom body output neurons, which store the current value of odors, as well as the behavior of flies steering in a virtual environment. Thus, the DAN circuit known for discrete, associative learning also continuously updates odor values during navigation in a non-associative manner.
Natural variations within the glycan shield of SARS-CoV-2 impact viral spike dynamics
Authors: Newby Maddy L. , Fogarty Carl A. , Allen Joel D. , Butler John , Fadda Elisa , Crispin Max
Published: August 2022

The emergence of SARS-CoV-2 variants alters the efficacy of existing immunity, whether arisen naturally or through vaccination. Understanding the structure of the viral spike assists in determining the impact of mutations on the antigenic surface. One class of mutation impacts glycosylation attachment sites, which have the capacity to influence the antigenic structure beyond the immediate site of attachment. Here, we compare the glycosylation of a recombinant viral spike mimetic of the P.1 (Gamma) strain, which exhibits two additional N-linked glycan sites compared to the equivalent mimetic of the Wuhan strain. We determine the site-specific glycosylation of these variants and investigate the impact of these glycans by molecular dynamics. The N188 site is shown to exhibit very limited glycan maturation, consistent with limited enzyme accessibility. Structural modeling and molecular dynamics reveal that N188 is located within a cavity by the receptor binding domain, which influences the dynamics of these attachment domains. These observations suggest a mechanism whereby mutations affecting viral glycosylation sites have a structural impact across the antigenic surface.
MSH2 and MSH6 as size dependent cellular determinants for prime editing in human embryonic stem cells
Authors: Park Ju-Chan , Kim Yunjeong , Han Jun Hee , Kim Dayeon , Kim Jumee , Jang Hyeon-Ki , Bae Sangsu , Cha Hyuk-Jin
Published: August 2022

Potential applications of precise genome editing in human pluripotent stem cells (hPSCs), not only for isogenic disease modeling but also for ex vivo stem cell therapy, have urged the application of diverse genome editing tools in hPSCs. However, unlike differentiated somatic cells, the unique cellular properties of hPSCs (e.g., high susceptibility to DNA damage and active DNA repair) largely determine the overall efficiency of editing tools. Considering high demand of prime editors (PE), mostly due to its broad editing coverage compared to base editors, it is important to characterize the key molecular determinants of PE efficiency in hPSCs. Herein, we showed that MSH2 and MSH6, two main components of the MutSα complex of mismatch repair (MMR), are highly expressed in hPSCs and determine PE efficiency in an ‘editing size’-dependent manner. Importantly, loss of MSH2, which disrupts both MutSα and MutSβ complexes, was found to dramatically improve the efficiency of PE from one base to 10 bases, up to 50 folds. In contrast, genetic perturbation of MSH6, which solely abrogates MutSα activity, marginally improved the editing efficiency up to 3 base pairs. The size dependent effect of MSH2 or MSH6 on prime editing in hPSCs not only implies MMR is a major determinant of PE efficiency in hPSCs but also highlights the distinct roles of MutSα and MutSβ in the outcome of genome editing.
An examination of the divergent spatiotemporal signaling of GLP-1R versus GIPR in pancreatic beta cells
Authors: Manchanda Yusman , Bitsi Stavroula , Chen Shiqian , Broichhagen Johannes , de la Serna Jorge Bernardino , Jones Ben , Tomas Alejandra
Published: August 2022

The incretin receptors, glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR), are class B GPCRs and prime therapeutic targets for the treatment of type 2 diabetes (T2D) and obesity. They are expressed in pancreatic beta cells where they potentiate insulin release in response to food intake. Despite GIP being the main incretin in healthy individuals, GLP-1R has been favoured versus GIPR as a therapeutic target due to GIPR responses being blunted in T2D patients and the conflicting effects of GIPR agonists and antagonists in improving glucose tolerance and preventing weight gain. There is, however, a recently renewed interest in GIPR biology following the realisation that GIPR responses can be restored after an initial period of blood glucose normalization and the recent development of dual GLP-1R-GIPR agonists with superior capacity for the control of blood glucose levels and weight. The importance of GLP-1R trafficking and subcellular signaling in the control of receptor outputs is well established, but little is known about the pattern of spatiotemporal signaling from the GIPR in beta cells. Here we have directly compared the main trafficking and signaling characteristics of both receptors in pancreatic beta cells, finding striking differences in their propensities for internalization, recycling, and degradation, as well as plasma membrane versus endosomal activity, with potential implications for receptor-specific control of beta cell function.
Enhanced neutralization potency of an identical HIV neutralizing antibody expressed as different isotypes is achieved through genetically distinct mechanisms
Authors: Moyo-Gwete Thandeka , Scheepers Cathrine , Makhado Zanele , Kgagudi Prudence , Mzindle Nonkululeko B. , Ziki Rutendo , Madzorera Sharon , Manamela Nelia P. , Ayres Frances , Lambson Bronwen E. , Richardson Simone I. , Morris Lynn , Moore Penny L.
Published: August 2022

Antibodies with the same variable region can exist as multiple isotypes with varying neutralization potencies, though the mechanism for this is not fully defined. We previously isolated an HIV-directed IgA1 monoclonal antibody (mAb), CAP88-CH06, and showed that IgA1 and IgG3 isotypes of this antibody demonstrated enhanced neutralization compared to IgG1. To explore the mechanism behind this, hinge region and constant heavy chain (CH1) chimeras were constructed between the IgA1, IgG3 and IgG1 mAbs and assessed for neutralization activity, antibody-dependent cellular phagocytosis (ADCP) and antibodydependent cellular cytotoxicity (ADCC). Hinge chimeras revealed that the increased neutralization potency and phagocytosis of the IgG3 isotype was attributed to its longer hinge region. In contrast, for IgA1, CH1 chimeras showed that this region was responsible both for enhanced neutralization potency and decreased ADCP, though ADCC was not affected. Overall, these data show that the enhanced neutralization potency of CAP88-CH06 IgG3 and IgA1, compared to IgG1, is achieved through distinct mechanisms. Understanding the influence of the hinge and CH1 regions on Fab domain function may provide insights into the engineering of therapeutic antibodies with increased neutralization potency.
Upgraded imaging capabilities at the BAMline (BESSY II)
Authors: Markötter H. , Sintschuk M. , Britzke R. , Dayani S. , Bruno G.
Published: August 2022

The BAMline at the BESSY II synchrotron X-ray source has enabled research for more than 20 years in widely spread research fields such as materials science, biology, cultural heritage and medicine. As a nondestructive characterization method, synchrotron X-ray imaging, especially tomography, plays a particularly important role in structural characterization. A recent upgrade of key equipment of the BAMline widens its imaging capabilities: shorter scan acquisition times are now possible, in situ and operando studies can now be routinely performed, and different energy spectra can easily be set up. In fact, the upgraded double-multilayer monochromator brings full flexibility by yielding different energy spectra to optimize flux and energy resolution as desired. The upgraded detector (based on an sCMOS camera) also allows exploiting the higher flux with reduced readout times. Furthermore, an installed slip ring allows the sample stage to continuously rotate. The latter feature enables tomographic observation of processes occurring in the time scale of a few seconds.
Study of X-ray topography using the super-Borrmann effect
Authors: Matsui J. , Takatsu K. , Tsusaka Y.
Published: August 2022

X-ray topography exerting the super-Borrmann effect has been performed using synchrotron radiation to display dislocation images with a high-speed and high-resolution CMOS camera. Forward-transmitted X-rays are positively employed instead of reflected X-rays to reveal dislocations in relatively thick crystals by simultaneously exciting a pair of adjacent {111} planes owing to the super-Borrmann effect. Before the experiment, minimum values of the attenuation coefficients A
min

P
for σ and π polarizations of the incident X-rays in the three-beam case are calculated. Results demonstrate that A
min

P
for both polarizations are almost 20 times larger than those in the two-beam (usual Borrmann effect) case. The transmitted X-rays can be used to confirm the efficacy of taking topographs under the super-Borrmann conditions, as well as under multiple-diffraction conditions. Furthermore, super-Borrmann topographs can be considered for relatively thick crystals, where a conventional Lang X-ray topography technique is difficult to apply.
Fixed-target serial crystallography at the Structural Biology Center
Authors: Sherrell Darren A. , Lavens Alex , Wilamowski Mateusz , Kim Youngchang , Chard Ryan , Lazarski Krzysztof , Rosenbaum Gerold , Vescovi Rafael , Johnson Jessica L. , Akins Chase , Chang Changsoo , Michalska Karolina , Babnigg Gyorgy , Foster Ian , Joachimiak Andrzej
Published: August 2022

Serial synchrotron crystallography enables the study of protein structures under physiological temperature and reduced radiation damage by collection of data from thousands of crystals. The Structural Biology Center at Sector 19 of the Advanced Photon Source has implemented a fixed-target approach with a new 3D-printed mesh-holder optimized for sample handling. The holder immobilizes a crystal suspension or droplet emulsion on a nylon mesh, trapping and sealing a near-monolayer of crystals in its mother liquor between two thin Mylar films. Data can be rapidly collected in scan mode and analyzed in near real-time using piezoelectric linear stages assembled in an XYZ arrangement, controlled with a graphical user interface and analyzed using a high-performance computing pipeline. Here, the system was applied to two β-lactamases: a class D serine β-lactamase from Chitinophaga pinensis DSM 2588 and L1 metallo-β-lactamase from Stenotrophomonas maltophilia K279a.
Political connections, business strategy and tax aggressiveness: evidence from China
Authors: Fan Hong , Chen Liqiang
Published: August 2022

Purpose

The purpose of this paper is to investigate the effects of political connections on the association between firms' business strategy and their tax aggressiveness in an emerging economy such as China.

Design/methodology/approach

The authors study a large sample of Chinese public firms from 2011 to 2017 using a panel regression model. In addition, a change analysis, an instrument variable test and alternative measures/samples are implemented as robustness tests.

Findings

Firms adopting innovative business strategy are more tax aggressive overall. However, innovative firms with political connections are less tax aggressive compared to those without political connections.

Originality/value

This paper contributes to the understanding of firms' tax behaviors in an emerging economy setting. It suggests that there are costs associated with political connections, such as foregone tax saving opportunities, which are understudies in the prior literature.
Linking empowering leadership with workplace proactivity: the mediating role of psychological safety and knowledge sharing
Authors: Singh Abhishek
Published: August 2022

Purpose

This study aims to explore the association between empowering leadership and workplace proactivity.

Design/methodology/approach

The data have been collected through questionnaires from both the medical and non-medical staff members working in four National Accreditation Board for Hospitals & Healthcare (NABH)–accredited private hospitals in India. Confirmatory factor analysis has employed test reliability and validity and PROCESS MACRO (model 6) to test the proposed serial mediation model.

Findings

The results support the proposed hypotheses of the serial mediation model. Additionally, the authors have also found that psychological safety is a strong mediating variable than knowledge sharing between empowering leadership and workplace proactivity.

Research limitations/implications

The findings should be interpreted by considering the cross-sectional research design and self-reported measures.

Practical implications

An organization can use the findings to promote employee proactivity at the workplace.

Originality/value

The study makes an attempt to explore the underdeveloped relationship between empowering leadership and workplace proactivity in the context of Indian NABH-accredited hospitals based on the self-determination theory.
Estimating mechanical and dynamic properties of rubberized concrete using machine learning techniques: a comprehensive study
Authors: Habib Ahed , Yildirim Umut
Published: August 2022

Purpose

Currently, many experimental studies on the properties and behavior of rubberized concrete are available in the literature. These findings have motivated scholars to propose models for estimating some properties of rubberized concrete using traditional and advanced techniques. However, with the advancement of computational techniques and new estimation models, selecting a model that best estimates concrete's property is becoming challenging.

Design/methodology/approach

In this study, over 1,000 different experimental findings were obtained from the literature and used to investigate the capabilities of ten different machine learning algorithms in modeling the hardened density, compressive, splitting tensile, and flexural strengths, static and dynamic moduli, and damping ratio of rubberized concrete through adopting three different prediction approaches with respect to the inputs of the model.

Findings

In general, the study's findings have shown that XGBoosting and FFBP models result in the best performances compared to other techniques.

Originality/value

Previous studies have focused on the compressive strength of rubberized concrete as the main parameter to be estimated and rarely went into other characteristics of the material. In this study, the capabilities of different machine learning algorithms in predicting the properties of rubberized concrete were investigated and compared. Additionally, most of the studies adopted the direct estimation approach in which the concrete constituent materials are used as inputs to the prediction model. In contrast, this study evaluates three different prediction approaches based on the input parameters used, referred to as direct, generalized, and nondestructive methods.
Factors affecting the performance of construction industry during the COVID-19 pandemic: a case study in Turkey
Authors: Gumusburun Ayalp Gulden , Çivici Tülay
Published: August 2022

Purpose

The construction industry is a crucial industry for national development worldwide. Because the construction industry is tied to national and international economic activities, the COVID-19 outbreak has limited construction projects. Therefore, this study investigates the most influential factors regarding COVID-19 and their effects on the construction industry.

Design/methodology/approach

The potential impacts of COVID-19 on the construction industry were identified through a realistic literature review and interviews with professionals. A questionnaire was distributed via e-mail to architects, civil engineers and contractors who play vital roles during the construction processes. The data were analysed using SPSS 22 and LISREL 8.7 software to quantify the most influential pandemic-related factors faced by the construction industry.

Findings

Ten influential pandemic factors affecting the construction industry in Turkey were identified. Among them, “increased costs and price escalations due to shortage of raw materials and supply chain disruption” and “challenges with payment and cash flows” were determined as the most influential pandemic factors.

Research limitations/implications

This research aims to advance comprehension of pandemic impacts and contributes an incipient assessment framework based on 10 determined pandemic factors. Therefore, contractors, architects and civil engineers may analyse their weaknesses and organise precise priorities so that their firms may remain competitive, thus minimising the adverse impact of COVID-19 and possible forthcoming waves.

Originality/value

Few studies have identified the effect of pandemics on the construction industry qualitatively, forcing management to make projections to the current situation. Moreover, no study has provided insights into the influential factors of pandemics using quantitative methods. Therefore, this study comprehensively and quantitatively determines the relevant COVID-19 pandemic factors using exploratory factor analysis (EFA) and utilises confirmatory factor analysis (CFA) and structural equation modelling to present a structural model of how pandemic factors affect the Turkish construction industry.
Investigation of requisite measures for enhancing sustainable construction practices in Indonesia
Authors: Fitriani Heni , Ajayi Saheed
Published: August 2022

Purpose

This study investigates the requisite measures for enhancing sustainability practices within the Indonesian construction industry based on professional perspectives.

Design/methodology/approach

This study used quantitative approach for data collection. A survey was conducted, using a questionnaire completed by 482 Indonesian construction professionals as a research instrument, and data were analyzed through reliability and exploratory factor analysis.

Findings

The findings suggest that for sustainability practices to become widely implemented within the Indonesian construction industry, certain measures are required. These include the need to raise awareness through education, development of standardized benchmarks, and the implementation of appraisal systems by the government, professional bodies, and academic institutions. These approaches are expected to build capacity and enhance the knowledge of sustainability among construction professionals and their clients. In addition, sustainable construction practices could be encouraged through a subsidized green market, which could be finalized supported by the government from financial penalties levied against non-sustainable practices.

Originality/value

By implementing the underlying strategies within the Indonesian construction industry, the poor knowledge, awareness, implementation, and motivation for sustainable practices within the Indonesian construction industry could be addressed, thereby reducing the environmental impacts associated with buildings and construction activities.
Ordeal or opportunity: IDPS journey through COVID-19 pandemic
Authors: Dimple Dimple , Nirmal Deepak Datta , Kumar Manoj , Puri Veerma
Published: August 2022

Learning outcomes

This case enables students to understand the nature of a typical crisis and manage a crisis drawing insights from the protagonist handling of the crisis and from the various crisis management models in the literature. The rich description of the impact of COVID-19 pandemic on the world in this case enables students to understand the nature of a typical external crisis. The critical appraisal of the protagonist’s plans and actions to overcome the crisis enables students to appreciate the various crisis management frameworks or models. In addition, students get perspectives about the leadership skills and competencies required during a crisis. In this way, students will not only learn about the theoretical concepts related to the crisis but also the practical know-how to effectively handle the crisis.

Case overview/synopsis

This case study describes the functioning of the International Delhi Public School (IDPS) Akhnoor, Jammu, and Kashmir, India, through the COVID-19 global crisis. The IDPS academic operations were disrupted because of the COVID-19 global crisis in March 2020. The protagonist, KCS Mehta, the school principal of IDPS, faced with the crisis, takes various steps to ensure the smooth transition of school’s academic operations from the physical mode to the online mode. This case explains the nature of an external crisis that completely crippled the organization’s day-to-day operations and how the organization’s leader tried to manage the crisis to revitalize the organization’s operations. The case can be used for teaching of alternate Models of Crisis Management and Change Management.

Complexity academic level

The case is developed to teach the courses of Executive training programs and MBA programs in business schools.

Supplementary materials

Teaching notes are available for educators only.

Subject code

CSS 11: Strategy.
An empirical examination of AIS success at the organizational level in the era of COVID-19 pandemic
Authors: Al-Hattami Hamood Mohammed , Senan Nabil Ahmed Mareai , Al-Hakimi Mohammed A. , Azharuddin Syed
Published: August 2022

Purpose

This study aims to empirically examine accounting information system (AIS) success at the organizational level during COVID-19 era.

Design/methodology/approach

Based on the information system success model, this paper developed its model and proposed a total of nine hypotheses. This paper gathered the required data via a questionnaire from Yemeni small and medium enterprises (SMEs) owners and managers. To test the proposed research model paths, SmartPLS software, which is known as partial least squares structural equation modeling, was used.

Findings

The results showed that the quality dimensions (information quality and system quality) positively affected the use of AIS and satisfaction; user satisfaction positively affected the use of AIS. Management support positively affected the AIS users' usage and satisfaction. Finally, the use dimensions (user satisfaction and usage) positively impacted the net benefits in terms of gaining a competitive advantage, productivity enhancement and saving time and cost. In all, this research has succeeded in providing support for DeLone and McLean's IS success model at the organizational level during the COVID-19 era.

Practical implications

AIS is becoming increasingly important for SMEs in low-income countries like Yemen, particularly in the present pandemic conditions (COVID-19 era). By using AIS, users can access the enterprise's data and conduct transactions without being limited by distance. Indeed, AIS proved its ability in enhancing the net benefits at the organizational level in the COVID-19 era in terms of gaining a competitive advantage, productivity enhancement and saving time and cost. However, AIS can only be considered useful to the enterprise if it is effective/successful.

Originality/value

This study is one of the first to have assessed the impact of AIS success at the organizational level in the era of COVID-19 pandemic, the context of Yemeni SMEs.
Understanding technostress and employee well-being in digital work: the roles of work exhaustion and workplace knowledge diversity
Authors: Wang Huatian , Ding Hua , Kong Xiansui
Published: August 2022

Purpose

Technostress is becoming one of the main challenges among employees in the increasingly digital work context. Following the job demands-resources (JD-R) theory, this study aims to understand how technostress (e.g. techno-overload, techno-complexity, techno-insecurity and techno-uncertainty) decreases employees’ work well-being through exhausting one’s emotional and physical resources (i.e. work exhaustion), and to what extent workplace knowledge diversity could buffer this relationship.

Design/methodology/approach

The authors collected three-wave data of 235 employees from three manufacturing companies in China. They conducted a moderated mediation model to test their hypotheses.

Findings

The results showed that work exhaustion mediated the relationship between technostress and employee work well-being and that perceived workplace knowledge diversity buffered this indirect effect.

Originality/value

This study might be one of the first attempts using the JD-R theory together with a three-wave longitudinal survey design to empirically examine the mediating role of work exhaustion and the moderating role of workplace knowledge diversity. The authors contribute to the information and technology management literature by underscoring the importance of being aware of technostress and managing technology-induced work exhaustion. They highlight that a knowledge-diverse work environment is an essential context that can help employees to handle difficult and complex tasks presented by various technologies and alleviate experienced technostress.