bluuebunny/crossref_metadata_2025 huggingface dataset:
Postnatal development of centrifugal inputs to the olfactory bulb
Authors: Kostka Johanna K. , Bitzenhofer Sebastian H.
Published: November 2021

Processing in primary sensory areas is influenced by centrifugal inputs from higher brain areas, providing information about behavioral state, attention, or context. Activity in the olfactory bulb, the first central processing stage of olfactory information, is dynamically modulated by direct projections from a variety of areas in adult mice. Despite the early onset of olfactory sensation compared to other senses, the development of centrifugal inputs to the olfactory bulb remains largely unknown. Using retrograde tracing across development, we show that centrifugal projections to the olfactory bulb are established during the postnatal period in an area-specific manner. While feedback projections from the piriform cortex are already present shortly after birth, they strongly increase in number during postnatal development with an anterior-posterior gradient. Contralateral projections from the anterior olfactory nucleus are present at birth but only appeared postnatally for the nucleus of the lateral olfactory tract. Numbers of olfactory bulb projecting neurons from the lateral entorhinal cortex, ventral hippocampus, and cortical amygdala show a sudden increase at the beginning of the second postnatal week and a delayed development compared to more anterior areas. These anatomical data suggest that limited top-down influence on odor processing in the olfactory bulb may be present at birth, but strongly increases during postnatal development and is only fully established later in life.
Protein Engineering with A Glycosylation Circuit Enables Improved Enzyme Characteristics
Authors: Bozkurt Eray Ulaş , Çağıl İrem Niran , Kehribar Ebru Şahin , Işılak Musa Efe , Şeker Urartu Özgür Şafak
Published: November 2021

Protein glycosylation is one of the most crucial and common post-translational modifications. It plays a fate-determining role and can alter many properties of proteins, making it an interesting for many biotechnology applications. The discovery of bacterial glycosylation mechanisms, opened a new perspective and transfer of C.jejuni N-linked glycosylation into laboratory work-horse E. coli increased research pace in the field exponentially. It has been previously showed that utilizing N-Linked Glycosylation, certain recombinant proteins have been furnished with improved features, such as stability and solubility. In this study, we utilized N-linked Glycosylation to glycosylate alkaline phosphatase (ALP) enzyme in E. coli and investigate the effects of glycosylation on an enzyme. Considering the glycosylation mechanism is highly dependent on the acceptor protein, ALP constructs carrying glycosylation tag at different locations of the gene has been created and glycosylation rates have been calculated. The most glycosylated construct has been selected for comparison with the native enzyme. We investigated the performance of glycosylated ALP in terms of its thermostability, proteolytic stability, tolerance to suboptimal pH and under denaturing conditions. Studies showed that glycosylated ALP performed remarkably better at optimal and harsh conditions Therefore, N-linked Glycosylation mechanism can be employed for enzyme engineering purposes and is a useful tool for industrial applications that require enzymatic activity.
Prey speed up, predators slow down: non-consumptive effects on movement behavior of a ciliate predator-prey pair
Authors: Daugaard Uriah , Furrer Reinhard , Petchey Owen L.
Published: November 2021

Non-consumptive effects (NCEs) of predators on prey, such as induced defensive strategies, are frequently neglected in the analysis of predator-prey interactions. Yet these effects can have demographic impacts as strong as consumption. As a counterpart to NCEs, resource-availability effects (RAEs) can prompt changes in predators as well, e.g., in their foraging behavior. We studied NCEs and RAEs in the ciliate predator-prey pairDidinium nasutumandParamecium caudatum. We examined the dependence of prey/predator swimming speed and body size on predator/prey presence. We also investigated prey spatial grouping behavior and the dependence of predator movement on local prey abundance. We collected individual movement and morphology data through videography of laboratory-based populations. We compared swimming speeds and body sizes based on their distributions. We used linear models to respectively quantify the effects of local prey abundance on predator displacements and of predator presence on prey grouping behavior. In the presence of prey, predator individuals swam more slowly, were bigger and made smaller displacements. Further, their displacements decreased with increasing local prey abundance. In contrast, in the presence of predators, proportionally more prey individuals showed a fast-swimming behavior and there was weak evidence for increased prey grouping. Trait changes entail energy expenditure shifts, which likely affect interspecific interactions and populations, as has been shown for NCEs. Less is known about the link between RAEs and demography, but it seems likely that the observed effects scale up to influence community and ecosystem stability, yet this remains largely unexplored.

Significance Statement

To maximize their fitness, organisms balance investment in foraging and avoiding being eaten. The behaviors of prey and predators are thus expected to depend on the presence and absence of each other and serve either to boost the chances of predation evasion or to increase predation success. Here we provide an example of the co-dependence of behaviors in the predator-prey pairDidinium nasutumandParamecium caudatum. We show that the predator slows down and searches in smaller areas when prey are present, while the prey speeds up and possibly groups more as a response to the presence of predators. Such behavioral changes are likely to have a demographic and community impact that is not accounted for with common measures of predators-prey interactions.
Retinal input influences pace of neurogenesis but not cell-type configuration of the visual forebrain
Authors: Sherman Shachar , Kawakami Koichi , Baier Herwig
Published: November 2021

The brain is assembled during development by both innate and experience-dependent mechanisms1–7, but the relative contribution of these factors is poorly understood. Axons of retinal ganglion cells (RGCs) connect the eye to the brain, forming a bottleneck for the transmission of visual information to central visual areas. RGCs secrete molecules from their axons that control proliferation, differentiation and migration of downstream components7–9. Spontaneously generated waves of retinal activity, but also intense visual stimulation, can entrain responses of RGCs10 and central neurons11–16. Here we asked how the cellular composition of central targets is altered in a vertebrate brain that is depleted of retinal input throughout development. For this, we first established a molecular catalog17 and gene expression atlas18 of neuronal subpopulations in the retinorecipient areas of larval zebrafish. We then searched for changes in lakritz (atoh7-) mutants, in which RGCs do not form19. Although individual forebrain-expressed genes are dysregulated in lakritz mutants, the complete set of 77 putative neuronal cell types in thalamus, pretectum and tectum are present. While neurogenesis and differentiation trajectories are overall unaltered, a greater proportion of cells remain in an uncommitted progenitor stage in the mutant. Optogenetic stimulation of a pretectal area20,21 evokes a visual behavior in blind mutants indistinguishable from wildtype. Our analysis shows that, in this vertebrate visual system, neurons are produced more slowly, but specified and wired up in a proper configuration in the absence of any retinal signals.
Multivalent peptide ligands to probe the chromocenter microenvironment in living cells
Authors: Guidotti Nora , Eördögh Ádám , Mivelaz Maxime , Rivera-Fuentes Pablo , Fierz Beat
Published: November 2021

Chromatin is spatially organized into functional states that are defined by both the presence of specific histone post-translational modifications (PTMs) and a defined set of chromatin-associated ‘reader’ proteins. Different models for the underlying mechanism of such compartmentalization have been proposed, including liquid-liquid phase separation (LLPS) of chromatin-associated proteins to drive spatial organization. Heterochromatin, characterized by lysine 9 methylation on histone H3 (H3K9me3) and the presence of heterochromatin protein 1 (HP1) as a multivalent reader, represents a prime example of a spatially defined chromatin state. Heterochromatin foci exhibit features of protein condensates driven by LLPS; however, the exact nature of the physicochemical environment within heterochromatin in different cell types is not completely understood. Here, we present tools to interrogate the environment of chromatin sub-compartments in the form of modular, cell-permeable, multivalent and fluorescent peptide probes. These probes can be tuned to target specific chromatin states by providing binding sites to reader proteins and can thereby integrate into the PTM-reader interaction network. As a target, here we generate probes specific to HP1, directing them to heterochromatin at chromocenters in mouse fibroblasts. Moreover, we use a polarity-sensing photoactivatable probe that photoconverts to a fluorescent state in phase-separated protein droplets and thereby reports on the local microenvironment. Equipped with this dye, our probes indeed turn fluorescent in murine chromocenters. However, image analysis and single-molecule tracking experiments reveal that the compartments are less dense and more dynamic than HP1 condensates obtained in vitro. Our results thus demonstrate that the local organization of heterochromatin in chromocenters is internally more complex than an HP1 condensate.
Efficient inhibition of cell proliferation and promotion of apoptosis requires continuous treatment with abemaciclib
Authors: Raquel Torres-Guzmán , Patricia Ganado Maria , Cecilia Mur , Carlos Marugán , Carmen Baquero , Yanzhu Yang , Zeng Yi , Huimin Bian , Jian Du , Alfonso de Dios , Oscar Puig , Jose Lallena Maria
Published: November 2021

Abemaciclib is an oral, selective cyclin-dependent kinase 4 & 6 inhibitor (CDK4 & 6i), approved for hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC) as monotherapy for endocrine refractory disease, and with endocrine therapy (ET) for initial treatment and after progression on ET. Abemaciclib has also shown clinical activity in combination with ET in patients with high risk early BC (EBC). Here, we examined the preclinical attributes of abemaciclib and other CDK4 & 6i using biochemical and cell-based assays. In vitro, abemaciclib preferentially inhibited CDK4 kinase activity versus CDK6, resulting in inhibition of cell proliferation in a panel of BC cell lines with higher average potency than palbociclib or ribociclib. Abemaciclib showed activity regardless of HER2 amplification and phosphatidylinositol 3-kinase (PI3KCA) gene mutation status. In human bone marrow progenitor cells, abemaciclib showed lower impact on myeloid maturation than other CDK4 & 6i when tested at unbound concentrations similar to those observed in clinical trials. Continuous abemaciclib treatment provided profound inhibition of cell proliferation, and triggered senescence and apoptosis. These preclinical results support the unique efficacy and safety profile of abemaciclib observed in clinical trials.
Deep embedding and alignment of protein sequences
Authors: Llinares-López Felipe , Berthet Quentin , Blondel Mathieu , Teboul Olivier , Vert Jean-Philippe
Published: November 2021

Protein sequence alignment is a key component of most bioinformatics pipelines to study the structures and functions of proteins. Aligning highly divergent sequences remains, however, a difficult task that current algorithms often fail to perform accurately, leaving many proteins or open reading frames poorly annotated. Here, we leverage recent advances in deep learning for language modelling and differentiable programming to propose DEDAL, a flexible model to align protein sequences and detect homologs. DEDAL is a machine learning-based model that learns to align sequences by observing large datasets of raw protein sequences and of correct alignments. Once trained, we show that DEDAL improves by up to two- or three-fold the alignment correctness over existing methods on remote homologs, and better discriminates remote homologs from evolutionarily unrelated sequences, paving the way to improvements on many downstream tasks relying on sequence alignment in structural and functional genomics.
NucleoMap: a computational tool for identifying nucleosomes in ultra-high resolution contact maps
Authors: Huang Yuanhao , Wang Bingjiang , Liu Jie
Published: November 2021

1

Although poorly positioned nucleosomes are ubiquitous in the prokaryote genome, they are difficult to identify with existing nucleosome identification methods. Recently available enhanced high-throughput chromatin conformation capture techniques such as Micro-C, DNase Hi-C, and Hi-CO characterize nucleosome-level chromatin proximity, probing the positions of mono-nucleosomes and the spacing between nucleosome pairs at the same time, enabling profiling of nucleosomes in poorly positioned regions. Here we develop a novel computational approach, NucleoMap, to identify nucleosome positioning from ultra-high resolution chromatin contact maps. By integrating nucleosome binding preferences, read density, and pairing information, NucleoMap precisely locates nucleosomes in both eukaryotic and prokaryotic genomes and outperforms existing nucleosome identification methods in precision and recall. We rigorously characterize genome-wide association in eukaryotes between the spatial organization of mono-nucleosomes and their corresponding histone modifications, protein binding activities, and higher-order chromatin functions. We also predict two tetra-nucleosome folding structures in human embryonic stem cells using machine learning methods and analysis their distribution at different structural and functional regions. Based on the identified nucleosomes, nucleosome contact maps are constructed, reflecting the inter-nucleosome distances and preserving the original data’s contact distance profile.
Random attention can explain apparent object choice behavior in free-walking blowflies
Authors: Monteagudo José , Egelhaaf Martin , Lindemann Jens Peter
Published: November 2021

Flies are often observed to approach dark objects. To a naïve observer they seem to pay selective attention to one out of several objects although previous research identified a reflex-like fixation behavior integrating responses to all objects as possible underlying mechanism. In a combination of behavioral experiments and computational modelling, we investigate the choice behavior of flies freely walking towards an arrangement of two objects placed at a variable distance from each other. The walking trajectories are oriented towards one of the objects much earlier than predicted by a simple reactive model. We show that object choice can be explained by a continuous control scheme in combination with a mechanism randomly responding to the position of each object according to a stochastic process. Although this may be viewed as a special form of an attention-like mechanism, the model does not require an explicit decision mechanism or a memory for the drawn decision.

Summary Statement

Walking blowflies apparently choose one of two objects to approach. In model simulations, a fixation scheme combined with random attention replicates this behavior without an explicit decision mechanism.
Polo-like kinase 4 homodimerization is not required for catalytic activation, autodestruction, or centriole assembly
Authors: Ryniawec John M. , Buster Daniel W. , Slevin Lauren K. , Boese Cody J. , Amoiroglou Anastasia , Dean Spencer M. , Slep Kevin C. , Rogers Gregory C.
Published: November 2021

Polo-like kinase 4 (Plk4) is the master-regulator of centriole assembly and cell cycle-dependent regulation of its activity maintains proper centrosome number. During most of the cell cycle, Plk4 levels are nearly undetectable due to its ability to autophosphorylate and trigger its own ubiquitin-mediated degradation. However, during mitotic exit, Plk4 forms a single aggregate on the centriole surface to stimulate centriole duplication. Whereas most Polo-like kinase family members are monomeric, Plk4 is unique because it forms homodimers. Notably, Plk4 trans-autophosphorylates a degron near its kinase domain, a critical step in autodestruction. While it is thought that the purpose of homodimerization is to promote trans-autophosphorylation, this has not been tested. Here, we generate separation-of-function Plk4 mutants that fail to dimerize, and we show that homodimerization is required to create a binding site for the Plk4 activator, Asterless. Surprisingly, Plk4 dimer mutants are catalytically active in cells, promote centriole assembly, and can trans-autophosphorylate by a process based its on concentration-dependent aggregation. Our findings implicate a concentration-dependent pathway of Plk4 activation that does not require Asterless binding or homodimerization. Lastly, we propose a model of Plk4 cell cycle regulation that utilizes both activation pathways – Asterless-dependent and aggregation-driven – to restrict centriole assembly to mother centrioles.
Structure and functionality of a multimeric human COQ7:COQ9 complex
Authors: Manicki Mateusz , Aydin Halil , Abriata Luciano A. , Overmyer Katherine A. , Guerra Rachel M. , Coon Joshua J. , Peraro Matteo Dal , Frost Adam , Pagliarini David J.
Published: November 2021

Coenzyme Q (CoQ, ubiquinone) is a redox-active lipid essential for core metabolic pathways and antioxidant defense. CoQ is synthesized upon the mitochondrial inner membrane by an ill-defined ‘complex Q’ metabolon. Here we present a structure and functional analyses of a substrate- and NADH-bound oligomeric complex comprised of two complex Q subunits: the hydroxylase COQ7, which performs the penultimate step in CoQ biosynthesis, and the prenyl lipid-binding protein COQ9. We reveal that COQ7 adopts a modified ferritin-like fold with an extended hydrophobic access channel whose substrate binding capacity is enhanced by COQ9. Using molecular dynamics simulations, we further show that two COQ7:COQ9 heterodimers form a curved tetramer that deforms the membrane, potentially opening a pathway for CoQ intermediates to translocate from within the bilayer to the proteins’ lipid-binding sites. Two such tetramers assemble into a soluble octamer, closed like a capsid, with lipids captured within. Together, these observations indicate that COQ7 and COQ9 cooperate to access hydrophobic precursors and coordinate subsequent synthesis steps toward producing mature CoQ.
The evolution of widespread recombination suppression on the Dwarf Hamster (Phodopus) X chromosome
Authors: Moore Emily C. , Thomas Gregg W. C. , Mortimer Sebastian , Kopania Emily E. K. , Hunnicutt Kelsie E. , Clare-Salzler Zachary J. , Larson Erica L. , Good Jeffrey M.
Published: November 2021

The mammalian X chromosome shows strong conservation among distantly related species, limiting insights into the distinct selective processes that have shaped sex chromosome evolution. We constructed a chromosome-scale de novo genome assembly for the Siberian dwarf hamster (Phodopus sungorus), a species reported to show extensive recombination suppression across an entire arm of the X chromosome. Combining a physical genome assembly based on shotgun and long-range proximity ligation sequencing with a dense genetic map, we detected widespread suppression of female recombination across ∼65% of the Phodopus X chromosome. This region of suppressed recombination likely corresponds to the Xp arm, which has previously been shown to be highly heterochromatic. Using additional sequencing data from two closely-related species (P. campbelli and P. roborovskii), we show that recombination suppression on Xp appears to be independent of major structural rearrangements. The suppressed Xp arm was enriched for several transposable element families and de-enriched for genes primarily expressed in the placenta, but otherwise showed similar gene densities, expression patterns, and rates of molecular evolution when compared to the recombinant Xq arm. Phodopus Xp gene content and order was also broadly conserved relative to the more distantly related rat X chromosome. Collectively, these data suggest that widespread suppression of recombination has likely evolved through the transient induction of facultative heterochromatin on the Phodopus Xp arm without major changes in chromosome structure or genetic content. Thus, dramatic changes in the recombination landscape have so far had relatively subtle influences on overall patterns of X-linked molecular evolution.

Significance Statement

Sex chromosome evolution represents a dynamic process of genomic specialization that is thought to be dependent on evolution of recombination. Here we use genome sequencing and genetic mapping to show that one arm comprising the majority of the X chromosome in a species of dwarf hamster has largely lost the ability to recombine in males and females. Although these dramatic shifts in recombination frequencies might eventually lead to sex chromosome degeneration, loss of recombination on this arm is associated with relatively minor changes in chromosome structure and gene contents in this species. These results underscore the conservation of the X chromosome across mammals, and allow us to test predictions about how genetic recombination influences sex chromosome evolution.
Structures of the Cyanobacterial Phycobilisome
Authors: Sauer Paul V. , Dominguez-Martin Maria Agustina , Kirst Henning , Sutter Markus , Bina David , Greber Basil J. , Nogales Eva , Polívka Tomáš , Kerfeld Cheryl A.
Published: November 2021

The phycobilisome is an elaborate antenna that is responsible for light-harvesting in cyanobacteria and red-algae. This large macromolecular complex captures incident sunlight and transfers the energy via a network of pigment molecules called bilins to the photosynthetic reaction centers. The phycobilisome of the model organism Synechocystis PCC 6803 consists of a core to which six rods are attached but its detailed molecular architecture and regulation in response to environmental conditions is not well understood. Here we present cryo-electron microscopy structures of the 6.2 MDa phycobilisome from Synechocystis PCC 6803 resolved at 2.1 Å (rods) to 2.7 Å (core), revealing three distinct conformations, two previously unknown. We found that two of the rods are mobile and can switch conformation within the complex, revealing a layer of regulation not described previously. In addition, we found a novel linker protein in the structure, that may represent a long-sought subunit that tethers the phycobilisome to the thylakoid membrane. Finally, we show how excitation energy is transferred within the phycobilisome and correlate our structures with known spectroscopic properties. Together, our results provide detailed insights into the biophysical underpinnings of cyanobacterial light harvesting and lay the foundation for bioengineering of future phycobilisome variants and artificial light harvesting systems.
River network rearrangements promote speciation in lowland Amazonian birds
Authors: Musher Lukas J. , Giakoumis Melina , Albert James , Del-Rio Glaucia , Rego Marco , Thom Gregory , Aleixo Alexandre , Ribas Camila C. , Brumfield Robb T. , Smith Brian Tilston , Cracraft Joel
Published: November 2021

Large Amazonian rivers impede dispersal for many species, but lowland river networks frequently rearrange, thereby altering the location and effectiveness of river-barriers through time. These rearrangements may promote biotic diversification by facilitating episodic allopatry and secondary contact among populations. We sequenced genome-wide markers to evaluate histories of divergence and introgression in six Amazonian avian species-complexes. We first tested the assumption that rivers are barriers for these taxa and found that even relatively small rivers facilitate divergence. We then tested whether species diverged with gene flow and recovered reticulate histories for all species, including one potential case of hybrid speciation. Our results support the hypothesis that river dynamics promote speciation and reveal that many rainforest taxa are micro-endemic, unrecognized and thus threatened with imminent extinction. We propose that Amazonian hyper-diversity originates in part from fine-scale barrier displacement processes –including river dynamics– which allow small populations to differentiate and disperse into secondary contact.
High COVID-19 vaccine coverage allows for a re-opening of European universities
Authors: Lasser Jana , Hell Timotheus , Garcia David
Published: November 2021

Returning universities to full on-campus operations while the COVID-19 pandemic is ongoing has been a controversial discussion in many countries. The risk of large outbreaks in dense course settings is contrasted by the benefits of in-person teaching. Transmission risk depends on a range of parameters, such as vaccination coverage, number of contacts and adoption of non-pharmaceutical intervention measures (NPIs). Due to the generalised academic freedom in Europe, many universities are asked to autonomously decide on and implement intervention measures and regulate on-campus operations. In the context of rapidly changing vaccination coverage and parameters of the virus, universities often lack the scientific facts to base these decisions on. To address this problem, we analyse a calibrated, data-driven simulation of transmission dynamics of 10755 students and 974 faculty in a medium-sized university. We use a co-location network reconstructed from student enrolment data and calibrate transmission risk based on outbreak size distributions in other Austrian education institutions. We focus on actionable interventions that are part of the already existing decision-making process of universities to provide guidance for concrete policy decisions. Here we show that with the vaccination coverage of about 80% recently reported for students in Austria, universities can be safely reopened if they either mandate masks or reduce lecture hall occupancy to 50%. Our results indicate that relaxing NPIs within an organisation based on the vaccination coverage of its sub-population can be a way towards limited normalcy, even if nation wide vaccination coverage is not sufficient to prevent large outbreaks yet.
Cbln1 regulates axon growth and guidance in multiple neural regions
Authors: Han Peng , She Yuanchu , Yang Zhuoxuan , Zhuang Mengru , Wang Qingjun , Luo Xiaopeng , Yin Chaoqun , Zhu Junda , Jaffrey Samie R. , Ji Sheng-Jian
Published: November 2021

The accurate construction of neural circuits requires the precise control of axon growth and guidance, which is regulated by multiple growth and guidance cues during early nervous system development. It is generally thought that the growth and guidance cues that control the major steps of axon guidance have been defined. Here, we describe cerebellin-1 (Cbln1) as a novel cue that controls diverse aspects of axon growth and guidance throughout the central nervous system (CNS). Cbln1 has previously been shown to function in late neural development to influence synapse organization. Here we find that Cbln1 has an essential role in early neural development. Cbln1 is expressed on the axons and growth cones of developing commissural neurons and functions in an autocrine manner to promote axon growth. Cbln1 is also expressed in intermediate target tissues and functions as an attractive guidance cue. We find that these functions of Cbln1 are mediated by neurexin-2 (Nrxn2), which functions as the Cbln1 receptor for axon growth and guidance. In addition to the developing spinal cord, we further show that Cbln1 functions in diverse parts of the CNS with major roles in cerebellar parallel fiber growth and retinal ganglion cell axon guidance. Despite the prevailing role of Cbln1 as a synaptic organizer, our study discovers a new and unexpected function for Cbln1 as a general axon growth and guidance cue throughout the nervous system.

Impact statement

Despite the prevailing role of Cbln1 as a synaptic organizer, our study discovers a new and unexpected function for Cbln1 as a general axon growth and guidance cue throughout the nervous system.
Optimizing the geometry of aerodynamic lens injectors for single-particle coherent diffractive imaging of gold nanoparticles
Authors: Worbs Lena , Roth Nils , Lübke Jannik , Estillore Armando D. , Xavier P. Lourdu , Samanta Amit K. , Küpper Jochen
Published: November 2021

Single-particle X-ray diffractive imaging (SPI) of small (bio-)nanoparticles (NPs) requires optimized injectors to collect sufficient diffraction patterns to allow for the reconstruction of the NP structure with high resolution. Typically, aerodynamic lens-stack injectors are used for NP injection. However, current injectors were developed for larger NPs (>100 nm), and their ability to generate high-density NP beams suffers with decreasing NP size. Here, an aerodynamic lens-stack injector with variable geometry and a geometry-optimization procedure are presented. The optimization for 50 nm gold-NP (AuNP) injection using a numerical-simulation infrastructure capable of calculating the carrier-gas flow and the particle trajectories through the injector is also introduced. The simulations were experimentally validated using spherical AuNPs and sucrose NPs. In addition, the optimized injector was compared with the standard-installation `Uppsala injector' for AuNPs. Results for these heavy particles showed a shift in the particle-beam focus position rather than a change in beam size, which results in a lower gas background for the optimized injector. Optimized aerodynamic lens-stack injectors will allow one to increase NP beam density, reduce the gas background, discover the limits of current injectors and contribute to structure determination of small NPs using SPI.
Co(NCS)2(abpt)2 and Ni(NCS)2(abpt)2 [abpt is 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole]: structural characterization of polymorphs A and B
Authors: Mason Helen E. , Howard Judith A. K. , Sparkes Hazel A.
Published: November 2021

The synthesis and structures of bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2
N
2,N
3]bis(thiocyanato-κN)cobalt(II), [Co(NCS)2(C12H10N6)2] or Co(NCS)2(abpt)2, and bis[4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole-κ2
N
2,N
3]bis(thiocyanato-κN)nickel(II), [Ni(NCS)2(C12H10N6)2] or Ni(NCS)2(abpt)2, are reported. In both cases, two polymorphs, A and B, were identified and structurally characterized. For both polymorphs, the structures obtained with the different metals, i.e. CoII or NiII, were found to be isostructural. All of the structures contained an intramolecular N—H...N hydrogen bond, C—H...N interactions and π–π stacking interactions. No structural evidence was observed for a thermal spin crossover for either of the Co(NCS)2(abpt)2 polymorphs between 300 (2) and 120 (2) K.
Crystal structure of 9-aminoacridinium chlorideN,N-dimethylformamide monosolvate
Authors: Fritsky Igor O. , Sirenko Valerii Y. , Shova Sergiu , Kucheriv Olesia I. , Gural'skiy Il'ya A.
Published: November 2021

9-Aminoacridinium chlorideN,N-dimethylformamide monosolvate, C13H11N2+Cl−·C3H7NO, crystallizes in the monoclinic space groupP21/c.The salt was crystallized fromN,N-dimethylformamide. The asymmetric unit consists of two C13H11N2+Cl−formula units. The 9-aminoacridinium (9-AA) molecules are protonated with the proton on the N atom of the central ring. This N atom is connected to anN,N-dimethylformamide molecule by a hydrogen bond. The H atoms of the amino groups create short contacts with two chloride ions. The 9-AA cations in adjacent layers are oriented in an antiparallel manner. The molecules are linkedviaa network of multidirectional π–π interactions between the 9-AA rings, and the whole lattice is additionally stabilized by electrostatic interactions between ions.
Knowledge creation and application of optimal tolerance distribution method for aircraft product assembly
Authors: Miah Md Helal , Zhang Jianhua , Singh Chand Dharmahinder
Published: November 2021

Purpose

This paper aims to illustrate the tolerance optimization method based on the assembly accuracy constrain, precession constrain and the cost of production of the assembly product.

Design/methodology/approach

A tolerance optimization method is an excellent way to perform product assembly performance. The tolerance optimization method is adapted to the process analysis of the hatch and skin of an aircraft. In this paper, the tolerance optimization techniques are applied to the tolerance allocation for step difference analysis (example: step difference between aircraft cabin door and fuselage outer skin). First, a mathematical model is described to understand the relationship between manufacturing cost and tolerance cost. Second, the penalty function method is applied to form a new equation for tolerance optimization. Finally, MATLAB software is used to calculate 170 loops iteration to understand the efficiency of the new equation for tolerance optimization.

Findings

The tolerance optimization method is based on the assembly accuracy constrain, machinery constrain and the cost of production of the assembly product. The main finding of this paper is the lowest assembly and lowest production costs that met the product tolerance specification.

Research limitations/implications

This paper illustrated an efficient method of tolerance allocation for products assembly. After 170 loops iterations, it founds that the results very close to the original required tolerance. But it can easily say that the different number of loops iterations may have a different result. But optimization result must be approximate to the original tolerance requirements.

Practical implications

It is evident from Table 4 that the tolerance of the closed loop is 1.3999 after the tolerance distribution is completed, which is less than and very close to the original tolerance of 1.40; the machining precision constraint of the outer skin of the cabin door and the fuselage is satisfied, and the assembly precision constraint of the closed loop is satisfied.

Originality/value

The research may support further research studies to minimize cost tolerance allocation using tolerance cost optimization techniques, which must meet the given constrain accuracy for assembly products.
Linking sustainability reporting frameworks and sustainable development goals
Authors: Stefanescu Cristina Alexandrina
Published: November 2021

Purpose

This study aims to explore the linkages between sustainable development and sustainability reporting by approaching the UN’s 2030 Agenda in connection with the Integrated Reporting (IR) and Global Reporting Initiative (GRI) frameworks. It aims to outline a theoretical model able to support the achievement of sustainable development goals (SDGs) through appropriate reporting.

Design/methodology/approach

The research methodology follows a qualitative approach, combining content and benchmarking analyses of the official documents in question. It aims to provide a better understanding of the conceptual matches between the “5 Ps” of sustainable development and the two sustainability reporting frameworks (IR and GRI) by breaking them down into components and overlapping their constituents to highlight the connections.

Findings

The results reveal that both sustainability reporting frameworks provide prerequisites to ensure SDGs achievement due to the embedded sustainability issues. As there are more matches between SDGs and the capitals implied in the pursuit of value creation, IR better fits to become part of the sustainable development strategy as a valuable option for reporting on SDGs.

Practical implications

The study addresses academia through a better understanding of the connections between SDGs and sustainability reporting. It might help regulators to improve their latest efforts to enhance transparency and comparability through the enactment of Directive 2014/95, as long as it has not imposed a standardised report yet. It could guide practitioners to face future challenges and support their steps towards standardised reporting practices.

Originality/value

This paper approaches the newsworthy topic of sustainable development, outlining a conceptual model meant to support the SDGs achievement through appropriate standardised reporting. It might also fill the gap of the Directive 2014/95 on non-financial information disclosure as it identifies the most suitable type of reporting to enhance the harmonisation at the European level.
Social media engagement and the determinants of behavioural intentions of university online programme selection: the moderating role of mindfulness
Authors: Konstantoulaki Kleopatra , Rizomyliotis Ioannis , Cao Yifei , Christodoulou Ioannis
Published: November 2021

Purpose

This study aims to explore the effect of social media engagement on the determinants of behavioural intention. Specifically, the authors empirically research the three behavioural intention determinants, namely, attitude, subjective norms and perceived behavioural control (PBC), and confirm their effect on students' intention to enrol on a university online programme.

Design/methodology/approach

A conclusive research analysis is followed, and a moderation analysis is conducted to test the hypotheses of the model. Empirical evidence from 201 students in the UK higher education is used and a structural equation modelling approach is followed.

Findings

The findings suggest a significant effect of social media engagement on attitude, subjective norms and PBC. The latter three are confirmed as determinants of the intention to enrol on a university online programme. Mindfulness is found to positively moderate the effect of the three determinants on behavioural intention.

Originality/value

This study advances knowledge pertaining to the theory of planned behaviour (TPB) by highlighting the effect of social media engagement on the determinants of the intention to enrol on a university online programme. Additionally, the moderating role of mindfulness is also tested with regards to its effect on the relationship between behavioural intentions and its determinants.
Too much of a good thing: the non-linear effect of vertical pay dispersion on vice presidents’ voluntary turnover rate
Authors: Xiong Xiaoguo , Chen Weihong , Zhong Xi
Published: November 2021

Purpose

While the effect of vertical pay dispersion on the voluntary turnover rate of vice presidents (VPs) has received attention, the existing research conclusions are still divided. Therefore, this study aims to explore the relationship between vertical pay dispersion and voluntary turnover rate of VPs in a Chinese context using data from listed firms.

Design/methodology/approach

Integrating tournament theory and social comparison theory, this study examines the non-linear effect of vertical pay dispersion on VPs’ voluntary turnover rates using empirical data from Chinese A-share listed firms from 2007 to 2016.

Findings

The results reveal a U-shaped relationship between vertical pay dispersion and the voluntary turnover rate of VPs. After further incorporating the moderating effect of the board governance structure, the effect is found to be enhanced in firms with more efficient board governance (i.e. smaller board size, higher board turnover and higher proportion of outside directors). Further analysis indicates that the aforementioned conclusions mainly exist in non-state-owned enterprises rather than state-owned enterprises.

Originality/value

The findings deepen the understanding of the costs and benefits associated with vertical pay dispersion, enrich the research findings on pay dispersion and contribute to the integration of previously inconsistent findings.
Systematic review on the identification of safety risks in off-site manufacturing (OSM)
Authors: Vithanage Sadith Chinthaka , Sing Michael , Davis Peter , Pillay Manikam
Published: November 2021

Purpose

Off-site manufacturing (OSM) has emerged as a method of modern construction that provides several benefits including achieving lower costs, a quicker schedule and environmentally friendly solutions. Although numerous researches are available that advocate the adoption of OSM, the devotion towards OSM safety is somewhat limited. However, OSM invariably generates safety risks, including dynamics and uncertainty in safety management. There is a unique call to have an investigation on the identification of OSM safety risks.

Design/methodology/approach

To provide a full picture on the OSM safety, a systematic literature review was adopted based on interpretivist philosophical stance. The literature search was conducted in key electronic databases to identify OSM safety-focused publications. Bibliometric analysis was adopted to identify co-occurrences of keywords and collaboration among authors in OSM safety-related research publications. Content analysis was conducted to provide a taxonomy of OSM safety risks. The identified studies were critically analysed to determine the focus of OSM safety research and provide future research directions.

Findings

The results demonstrated frequently appeared OSM safety aspects while highlighting the limitedness of collaborative research outputs in common authorships. Content analysis subsequently unveiled safety risks in OSM under human, organisational and work environmental factors. A critical analysis of extant literature revealed seven research classifications of OSM safety. Directions were offered to enhance OSM safety by applying principles of targeted safety management concepts, technology-driven safety measures and bespoke training programs.

Originality/value

This study provides a comprehensive review on the identification of safety risks throughout OSM while presenting the avenues useful for the development of OSM safety management strategies.
Why ethnic minority groups’ online-startups are booming in China’s tight cultural ecosystem?
Authors: Li Lifu , Kang Kyeong
Published: November 2021

Purpose

Although most Chinese ethnic minority groups (EMGs) hold conservative thinking to online-startups, the new entrepreneurial model is booming on live streaming platforms. In China’s tight cultural ecosystem, the tight cultural control would lead EMG entrepreneurs to keep conservative thinking and avoid challenging careers. Still, it would be helpful for Chinese Governments to issue systematical entrepreneurial policies and improve online-startup environment for EMGs. To discover the relationships among influencing factors and EMGs’ online-startup motivation, this paper aims to draw on the tight and loose cultural theory and the capability-opportunity-motivation-behaviour (COM-B) behaviour changing theory and establishes the research model based on China’s tight cultural ecosystem.

Design/methodology/approach

Through analysing 617 questionnaires from 37 EMGs based on the partial least squares path modelling and variance-based structural equation modelling method, the study proves that environmental opportunity factors and personal capability factors have positive impacts on EMGs’ online-startup motivation and EMGs’ conservative thinking negatively moderates the relationship between their online-startup motivation and entrepreneurial development behaviour. In addition to testing the hypotheses, the paper also measures the importance-performance map analysis to explore additional findings of influencing factors and provide suitable suggestions for EMG entrepreneurs and related departments.

Findings

Regarding the environmental opportunity unit, both policy support and platform support significantly impact Chinese EMGs’ motivation to promote online-startups. For the personal capability unit, a platform using skills positively influences Chinese EMGs to develop online-startups. Meanwhile, EMG cultural knowledge is also necessary for EMG entrepreneurs because abundant cultural resources can be applied to live content and attract online consumers’ watching interests. Furthermore, influenced by the tight cultural control, Chinese EMGs tend to hold conservative thinking to new careers and it negatively moderates the relationship between Chinese EMGs’ online-startup motivation and their final entrepreneurial behaviours. Finally, Chinese EMGs’ online-startup motivation positively affects them to develop online-startups on live streaming platforms.

Originality/value

This study uses the tight and loose cultural theory to analyse the Chinese entrepreneurial environment and discover influencing factors based on the tight cultural ecosystem. Meanwhile, based on the COM-B behaviour changing theory, this paper divides influencing factors into three different units, including the environmental opportunity unit, the personal capability unit and the Tight cultural control unit. Considering the inter-relationships among these units, the research model is established based on the tight cultural ecosystem to discover Chinese EMGs’ online-startup motivation.
Effects of knowledge management on the management of health and social care: a systematic literature review
Authors: Hujala Tuomas , Laihonen Harri
Published: November 2021

Purpose

The purpose of this study is twofold. First, it suggests that knowledge management (KM), as an academic discipline and managerial practice, provides valuable perspectives and tools to help health and social care management cope with both existing and future challenges. Second, it reviews the existing evidence on the effects of KM on the management of health and social care. Based on the results of the review, an evaluation framework for the effects of KM is proposed.

Design/methodology/approach

The literature review was conducted using the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement to search the Web of Science and SCOPUS databases. The search terms included “knowledge management”, “healthcare” and “effect.” Academic articles published between 2010 and 2020 were included.

Findings

The study identifies six main categories among the effects of KM on the management of health and social care as follows: enhanced understanding of customer needs, improved organizational performance, better targeted decision-making, improved quality of service, behavioral or cultural change and improved risk management.

Originality/value

This study contributes by summarizing the literature on the effects of KM on the management of health and social care and proposing avenues for future research in this area.