bluuebunny/crossref_metadata_2025 huggingface dataset:
Phage-Antibiotic Synergy is Driven by a Unique Combination of Antibacterial Mechanism of Action and Stoichiometry
Authors: Liu Carmen Gu , Green Sabrina I. , Min Lorna , Clark Justin R. , Salazar Keiko C. , Terwilliger Austen L. , Kaplan Heidi B. , Trautner Barbara W. , Ramig Robert F. , Maresso Anthony W.
Published: February 2020

The continued rise in antibiotic resistance is precipitating a medical crisis. Bacteriophage (phage) has been hailed as one possible therapeutic option to augment the efficacy of antibiotics. However, only a handful of studies have addressed the synergistic relationship between phage and antibiotics. Here, we report a comprehensive analysis of phage-antibiotic interaction that evaluates synergism, additivism, and antagonism for all classes of antibiotics across clinically achievable stoichiometries. We combined an optically-based real-time microtiter plate readout with a matrix-like heatmap of treatment potencies to measure phage and antibiotic synergy (PAS), a process we term synography. Phage-antibiotic synography was performed against a pandemic drug-resistant clonal group ofE. coli(ExPEC) with antibiotic levels blanketing the minimum inhibitor concentration (MIC) across seven orders of viral titers. Our results suggest that, under certain conditions, phages provide an adjuvating effect by lowering the MIC for drug-resistant strains. Furthermore, synergistic and antagonistic interactions are highly dependent on the mechanism of bacterial inhibition by the class of antibiotic paired to the phage, and when synergism is observed, it suppresses the emergence of resistant cells. Host conditions that simulate the infection environment, including serum and urine, suppress PAS in a bacterial growth-dependent manner. Lastly, phage burst size seems to be a significant driver of synergism. Collectively, this data suggests lytic phages can resuscitate an ineffective antibiotic for previously resistant bacteria, while also synergize with antibiotics in a class-dependent manner, processes that may be dampened by lower bacterial growth rates found in host environments.

Significance Statement

Bacteriophage (phage) therapy is a promising approach to combat the rise of multi-drug resistant bacteria. Currently, the preferred clinical modality is to pair phage with an antibiotic, a practice thought to improve efficacy. However, antagonism between phage and antibiotics has been reported, the choice of phage and antibiotic is not often empirically determined, and the effect of the host factors on the effectiveness is unknown. Here, we interrogate phage-antibiotic interactions across antibiotics with different mechanisms of action. Our results suggest that phage can lower the working MIC for bacterial strains already resistant to the antibiotic, is dependent on the antibiotic class and stoichiometry of the pairing, and is dramatically influenced by the host microenvironment.
Artificial diets modulate infection rates byNosema ceranaein bumblebees
Authors: Gómez-Moracho Tamara , Durand Tristan , Pasquaretta Cristian , Heeb Philipp , Lihoreau Mathieu
Published: February 2020

Parasites alter the physiology and behaviour of their hosts. In domestic honey bees, the microsporidiaNosema ceranaeinduces an energetic stress and impairs the behaviour of foragers, potentially leading to colony collapse. Whether this emerging parasite similarly affects wild pollinators is little understood because of the low success rates of experimental infection protocols. Here we established a new apporach for infecting bumblebees (Bombus terrestris) with controlled amounts ofN. ceranae, by briefly exposing individual bumblebees to a sucrose solution containing parasite spores, before feeding them with artificial diets. We validated our protocol by testing the effect of two spore dosages and two diets varying in their protein to carbohydrate ratio, on the prevalence of the parasite (proportion of infected bees), the intensity of infection (spore count in the gut), and the survival of bumblebees. Insects fed a low-protein high-carbohydrate diet showed highest parasite prevalence (up to 70%) but lived longest, suggesting that immunity and survival of bumblebees are maximised at different protein to carbohydrate ratios. Spore dosage had no effect on parasite infection rate and host survival. The identification of experimental conditions for successfully infecting bumblebees withN. ceranaein the lab will facilitate investigations of the sub-lethal effects of this parasite on the behaviour and cognition of wild pollinators.
CandiHap: a toolkit for haplotype analysis for sequence of samples and fast identification of candidate causal gene(s) in genome-wide association study
Authors: Li Xukai , Shi Zhiyong , Qie Qianru , Gao Jianhua , Wang Xingchun , Han Yuanhuai
Published: February 2020

Genome-wide association study (GWAS) is widely used to identify genes involved in plants, animals and human complex traits. Generally, the identified SNP is not necessarily the causal variant, but it is rather in linkage disequilibrium (LD). One key challenge for GWAS results interpretation is to rapidly identify causal genes and provide profound evidence on how they affect the trait. Researches want to identify candidate causal variants from the most significant SNPs of GWAS in any species and on their local computer, while to complete these tasks are to be time-consuming, laborious and prone to errors and omission. To our knowledge, so far there is no tool available to solve the challenge for GWAS data very quickly. Based on the standard VCF (variant call format) format, CandiHap is developed to fast preselection candidate causal SNPs and gene(s) from GWAS by integrating LD result, SNP annotation, haplotype analysis and traits statistics of haplotypes. Investigators can specify genes or linkage regions based on GWAS results, linkage disequilibrium (LD), and predicted candidate causal gene(s). It supported Windows, Mac and Linux computers and servers in graphical interface and command line, and applied to any other plant, animal or bacteria species. The source code of CandiHap tool is freely available athttps://github.com/xukaili/CandiHap
Colonization with the commensal fungusCandida albicansperturbs the gut-brain axis through dysregulation of endocannabinoid signaling
Authors: Markey Laura , Hooper Andrew , Melon Laverne C. , Baglot Samantha , Hill Matthew N. , Maguire Jamie , Kumamoto Carol A.
Published: February 2020

Anxiety disorders are the most prevalent mental health disorder worldwide, with a lifetime prevalence of 5-7% of the human population. Although the etiology of anxiety disorders is incompletely understood, one aspect of host health that affects anxiety disorders is the gut-brain axis. We used a mouse model of gastrointestinal (GI) colonization to demonstrate that the commensal fungusCandida albicansaffects host health via the gut-brain axis. In mice, bacterial members of the gut microbiota can influence the host gut-brain axis, affecting anxiety-like behavior and the hypothalamus-pituitary-adrenal (HPA) axis which produces the stress hormone corticosterone (CORT). Here we showed that mice colonized withC. albicansdemonstrated increased anxiety-like behavior and increased basal production of CORT as well as dysregulation of CORT production following acute stress. The HPA axis and anxiety-like behavior are negatively regulated by the endocannabinoid anandamide (AEA).C. albicans-colonizedmice exhibited systemic changes in the endocannabinoidome, within the GI tract and the brain, and showed a negative correlation between brain AEA levels and serum CORT. Further, increasing AEA levels using the well-characterized fatty acid amide hydrolase (FAAH) inhibitor URB597 was sufficient to reverse both neuroendocrine phenotypes inC. albicans-colonizedmice. Thus, a commensal fungus that is a common colonizer of humans had widespread effects on the physiology of its host. To our knowledge, this is the first report of microbial manipulation of the endocannabinoid (eCB) system that resulted in neuroendocrine changes contributing to anxiety-like behavior.
The serine-threonine kinase TAO3 promotes cancer invasion and tumor growth by facilitating trafficking of endosomes containing the invadopodia scaffold TKS5α
Authors: Iizuka Shinji , Quintavalle Manuela , Navarro Jose Ceja , Gribbin Kyle P. , Ardecky Robert J. , Abelman Matthew , Ma Chen-Ting , Sergienko Eduard , Zeng Fu-Yue , Pass Ian , Thomas George , McWeeney Shannon , Hassig Christian A. , Pinkerton Anthony B , Courtneidge Sara A
Published: February 2020

Invadopodia are actin-based proteolytic membrane protrusions required for invasive behavior and tumor growth. We used our high-content screening assay to identify kinases impacting invadopodia formation. Among the top hits we selected TAO3, a STE20-like kinase of the GCK subfamily, for further analysis. TAO3 was over-expressed in many human cancers, and regulated invadopodia formation in melanoma, breast and bladder cancers. Furthermore, TAO3 catalytic activity facilitated melanoma growth in 3-dimensional matrices andin vivo. We developed potent catalytic inhibitors of TAO3 that inhibited invadopodia formation and function, and tumor cell extravasation and growth. Using these inhibitors, we determined that TAO3 activity was required for endosomal trafficking of TKS5α, an obligate invadopodia scaffold protein. A phosphoproteomics screen for TAO3 substrates revealed the dynein subunit protein LIC2 as a relevant substrate. Knockdown of LIC2 or expression of a phosphomimetic form promoted invadopodia formation. Thus, TAO3 is a new therapeutic target with a distinct mechanism of action.

SIGNIFICANCE

Targeting tumor invasive behavior represents an understudied opportunity. We used an unbiased screening approach to identify kinases required for invadopodia formation and function. We validated TAO3, both genetically and with a novel inhibitor, and determined TAO3 function. Our data support clinical development of this class of target.
Seizure onset location shapes dynamics of initiation
Authors: Salami Pariya , Peled Noam , Nadalin Jessica K. , Martinet Louis-Emmanuel , Kramer Mark A. , Lee Jong W. , Cash Sydney S.
Published: February 2020

Objective

Ictal electrographic patterns are widely thought to reflect underlying neural mechanisms of seizures. Here we studied the degree to which seizure patterns are consistent in a given patient, relate to particular brain regions and if two candidate biomarkers (high-frequency oscillations, HFOs; infraslow activity, ISA) and network activity, as assessed with cross-frequency interactions, can discriminate between seizure types.

Methods

We analyzed temporal changes in low and high frequency oscillations recorded during seizures, as well as phase-amplitude coupling (PAC) to monitor the interactions between delta/theta and ripple/fast ripple frequency bands at seizure onset.

Results

Seizures of multiple pattern types were observed in a given patient and brain region. While there was an increase in HFO rate across different electrographic patterns, there are specific relationships between types of HFO activity and onset region. Similarly, changes in PAC dynamics were more closely related to seizure onset region than they were to electrographic patterns while ISA was a poor indicator for seizure onset.

Conclusions

Our findings suggest that the onset region sculpts neurodynamics at seizure initiation and that unique features of the cytoarchitecture and/or connectivity of that region play a significant role in determining seizure mechanism.

Significance

Clinicians should consider more than just overt electrographic patterns when considering seizure mechanisms and regions of onset. Examination of onset pattern in conjunction with the interactions between different oscillatory frequencies in the context of different brain regions might be more informative and lead to more reliable clinical inference as well as novel therapeutic approaches.
Phylogenomic analysis ofClostridiodes difficileribotype 106 strains reveals novel genetic islands and emergent phenotypes
Authors: Roxas Bryan Angelo P. , Roxas Jennifer Lising , Claus-Walker Rachel , Harishankar Anusha , Mansoor Asad , Anwar Farhan , Jillella Shobitha , Williams Alison , Lindsey Jason , Elliott Sean P. , Shehab Kareem W. , Viswanathan V.K. , Vedantam Gayatri
Published: February 2020

Background

Clostridioides difficileRT106 has emerged as a dominant molecular type in the USA in recent years, but the underlying factors contributing to its predominance remain undefined. As part of our ongoingC. difficileinfection (CDI) surveillance in Arizona, we monitored RT106 frequency and characterized the genomic and phenotypic properties of the recovered isolates.

Results

From 2015-2018, RT106 was the second-most prevalent molecular type isolated from CDI patients in our surveillance. A representative RT106 strain displayed robust virulence and 100% lethality in the hamster model of acute CDI. We identified a unique 46 KB genomic island (GI1) in all RT106 strains, including those in public databases. GI1 was not found in its entirety in any otherC. difficileclade, or indeed in any other microbial genome; however, smaller segments were detected in selectEnterococcus faeciumstrains. Molecular clock analyses suggest that GI1 was horizontally acquired and sequentially assembled over time. Consistent with the presence of genes encoding homologs of VanZ and a SrtB-anchored collagen-binding adhesin in GI1, all tested RT106 strains had increased teicoplanin resistance and a majority displayed collagen-dependent biofilm formation. Two additional genomic islands (GI2 and GI3) were also present in a subset of RT106 strains. All three islands have features of mobile genetic elements and encode several putative virulence factors.

Conclusions

Consistent with the known genetic plasticity ofC. difficile, strains belonging to the RT106 clade harbor unique genetic islands. Correspondingly, emergent phenotypic properties may contribute to the relatively rapid shifts of strain distribution in patient populations.
Deficits in olfactory sensitivity in a mouse model of Parkinson’s disease revealed by plethysmography of odor-evoked sniffing
Authors: Johnson Michaela E. , Bergkvist Liza , Mercado Gabriela , Stetzik Lucas , Meyerdirk Lindsay , Brundin Patrik , Wesson Daniel W.
Published: February 2020

Hyposmia is evident in over 90% of Parkinson’s disease (PD) patients. A characteristic of PD is intraneuronal deposits composed in part of α-synuclein fibrils. Based on the analysis of post-mortem PD patients, Braak and colleagues suggested that early in the disease α-synuclein pathology is present in the dorsal motor nucleus of the vagus, as well as the olfactory bulb and the anterior olfactory nucleus, and then later affects other interconnected brain regions. Here, we bilaterally injected α-synuclein preformed fibrils into the olfactory bulb of wild type male and female mice. Six-months after injection, the anterior olfactory nucleus and the piriform cortex displayed a high α-synuclein pathology load. We evaluated olfactory perceptual function by monitoring odor-evoked sniffing behavior in a plethysmograph at one-, three- and six-months after injection of α-synuclein fibrils. At all-time points, females injected with fibrils exhibited reduced odor detection sensitivity, which was detectable with the semi-automated plethysmography apparatus, but not a buried pellet test. In future studies, this sensitive methodology we used to assess olfactory detection deficits could be used to define how α-synuclein pathology affects other aspects of olfactory perception in PD models and to clarify the neuropathological underpinnings of these deficits.

Highlights

- α-synuclein pathology spreads through neuronally-connected areas after bilateral injection of preformed fibrils into the olfactory bulb.

- A plethysmograph and an olfactometer were used for a semi-automated screen of odor-evoked sniffing as an assay for odor detection sensitivity.

- Bilateral olfactory bulb injections of α-synuclein preformed fibrils in female mice led to reduced sensitivity for detecting odors.

- The semi-automated plethysmography apparatus was more sensitive at detecting odor detection deficits than the buried pellet test.
On the effects of climate change on Galápagos green turtleChelonia mydas agassiziineonate mortality in A1B
Authors: Gotts Max
Published: February 2020

Climate change affects every crevice and corner of the ecological world. Already we see seasonal effects on important ecosystems such as the marine habitats of the Galápagos Archipelago. This paper looks at the year 2100 in the IPCC scenario A1B, looking specifically atChelonia mydas agassiziiand seeing whether it will be a “winner” or a “loser” under climate change. We discover that while neonate hatchlings may benefit from a compressed laying period that offers them protection by way of numbers, and speed from the increased ocean temperatures (SST), they lose out many other places. Frigatebird and reef fish predation will increase, hatchling size and fitness may decrease, and a surplus of female hatchlings will be produced, or none at all as nest temperatures rise above the thermal mortality limit.Chelonia mydas agassiziiwill need serious conservation help if we wish to keep it on this earth by the year 2100 even if we opt for the A1B strategy.
Quantification of Adeno-Associated Virus with Safe Nucleic Acid Dyes
Authors: Xu Jian , DeVries Steven H , Zhu Yongling
Published: February 2020

Adeno-associated virus (AAV) is the most commonly used viral vector for both biological and gene therapeutic applications1. Although many methods have been developed to measure quantity attributes of AAV, they are often technically challenging and time consuming. Here we report a method to titer AAV with GelGreen® dye, a safe green fluorescence nucleic acid dye recently engineered by Biotium company (Fremont, CA). This method, hereinafter referred to as GelGreen method, provides a fast (~ 30 minutes) and reliable strategy for AAV titration. To validate GelGreen method, we measured genome titer of an AAV reference material AAV8RSM and compared our titration results with those determined by Reference Material Working Group (ARMWG). We showed that GelGreen results and capsid Elisa results are comparable to each other. We also showed that GelRed® dye, a red fluorescence dye from Biotium, can be used to directly “visualize” AAV genome titer on a conventional gel imager, presenting an especially direct approach to estimate viral quantity. In summary, we described a technique to titer AAV by using new generation of safe DNA dyes. This technique is simple, safe, reliable and cost-efficient. It has potential to be broadly applied for quantifying and normalizing AAV viral vectors.
Evolution of genome structure in theDrosophila simulansspecies complex
Authors: Chakraborty Mahul , Chang Ching-Ho , Khost Danielle E. , Vedanayagam Jeffrey , Adrion Jeffrey R. , Liao Yi , Montooth Kristi L. , Meiklejohn Colin D. , Larracuente Amanda M. , Emerson J.J.
Published: February 2020

The rapid evolution of repetitive DNA sequences, including satellite DNA, tandem duplications, and transposable elements, underlies phenotypic evolution and contributes to hybrid incompatibilities between species. However, repetitive genomic regions are fragmented and misassembled in most contemporary genome assemblies. We generated highly contiguousde novoreference genomes for theDrosophila simulansspecies complex (D. simulans, D. mauritiana, andD. sechellia), which speciated ∼250,000 years ago. Our assemblies are comparable in contiguity and accuracy to the currentD. melanogastergenome, allowing us to directly compare repetitive sequences between these four species. We find that at least 15% of theD. simulanscomplex species genomes fail to align uniquely toD. melanogasterdue to structural divergence—twice the number of single-nucleotide substitutions. We also find rapid turnover of satellite DNA and extensive structural divergence in heterochromatic regions, while the euchromatic gene content is mostly conserved. Despite the overall preservation of gene synteny, euchromatin in each species has been shaped by clade and species-specific inversions, transposable elements, expansions and contractions of satellite and tRNA tandem arrays, and gene duplications. We also find rapid divergence among Y-linked genes, including copy number variation and recent gene duplications from autosomes. Our assemblies provide a valuable resource for studying genome evolution and its consequences for phenotypic evolution in these genetic model species.
Fast, Rate-Independent, Finite Element Implementation of a 3D Constrained Mixture Model of Soft Tissue Growth and Remodeling
Authors: Latorre Marcos , Humphrey Jay D.
Published: February 2020

Constrained mixture models of soft tissue growth and remodeling can simulate many evolving conditions in health as well as in disease and its treatment, but they can be computationally expensive. In this paper, we derive a new fast, robust finite element implementation based on a concept of mechanobiological equilibrium that yields fully resolved solutions and allows computation of quasi-equilibrated evolutions when imposed perturbations are slow relative to the adaptive process. We demonstrate quadratic convergence and verify the model via comparisons with semi-analytical solutions for arterial mechanics. We further examine the enlargement of aortic aneurysms for which we identify new mechanobiological insights into factors that affect the nearby non-aneurysmal segment as it responds to the changing mechanics within the diseased segment. Because this new 3D approach can be implemented within many existing finite element solvers, constrained mixture models of growth and remodeling can now be used more widely.
Brassinosteroids Suppress Ethylene Biosynthesis via Transcription Factor BZR1 in Pear and Apple Fruit
Authors: Ji Yinglin , Qu Yi , Jiang Zhongyu , Su Xin , Yue Pengtao , Li Xinyue , Wang Yanan , Bu Haidong , Yuan Hui , Wang Aide
Published: February 2020

The plant hormone ethylene is important for the ripening of climacteric fruit, such as pear (Pyrus ussuriensis), and the brassinosteroid (BR) class of phytohormones affects ethylene biosynthesis during ripening, although via an unknown molecular mechanism. Here, we observed that exogenous BR treatment suppressed ethylene production during pear fruit ripening, and that the expression of the transcription factorPuBZR1was enhanced by epibrassinolide (EBR) treatment during pear fruit ripening. PuBZR1 was shown to interact with PuACO1, which converts 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, and suppress its activity. We also observed that BR-activated PuBZR1 bound to the promoters ofPuACO1and ofPuACS1a, which encodes ACC synthase, and directly suppressed their transcription. Moreover, PuBZR1 suppressed the expression of transcription factorPuERF2by binding its promoter, and PuERF2 bound to the promoters ofPuACO1andPuACS1a. We concluded that PuBZR1 indirectly suppresses the transcription ofPuACO1andPuACS1athrough its regulation of PuERF2. Ethylene production and the expression profiles of the corresponding apple (Malus domestica) homologs showed similar changes following EBR treatment. Together, these results suggest that BR-activated BZR1 suppresses ACO1 activity and the expression ofACO1andACS1a, thereby reducing ethylene production during pear and apple fruit ripening. This likely represents a conserved mechanism by which exogenous BR suppresses ethylene biosynthesis during climacteric fruit ripening.

One-sentence summary

BR-activated BZR1 suppresses ACO1 activity and expression ofACO1andACS1a, which encode two ethylene biosynthesis enzymes, thereby reducing ethylene production during pear and apple fruit ripening.
Molecular goniometers for single-particle cryo-EM of DNA-binding proteins
Authors: Aksel Tural , Yu Zanlin , Cheng Yifan , Douglas Shawn M.
Published: February 2020

Correct reconstruction of macromolecular structure by cryo-electron microscopy relies on accurate determination of the orientation of single-particle images. For small (<100 kDa) DNA-binding proteins, obtaining particle images with sufficiently asymmetric features to correctly guide alignment is challenging. DNA nanotechnology was conceived as a potential tool for building host nanostructures to prescribe the locations and orientations of docked proteins. We used DNA origami to construct molecular goniometers—instruments to precisely orient objects—to dock a DNA-binding protein on a double-helix stage that has user-programmable tilt and rotation angles. Each protein orientation maps to a distinct barcode pattern specifying particle classification and angle assignment. We used goniometers to obtain a 6.5 Å structure of BurrH, an 82-kDa DNA-binding protein whose helical pseudosymmetry prevents accurate image orientation using classical cryo-EM. Our approach should be adaptable for other DNA-binding proteins, and a wide variety of other small proteins, by fusing DNA binding domains to them.
Structure-guided DNA-DNA attraction mediated by divalent cations
Authors: Srivastava Amit , Timsina Raju , Heo Seung , Dewage Sajeewa Walimuni , Kirmizialtin Serdal , Qiu Xiangyun
Published: February 2020

Probing the role of surface structure in electrostatic interactions, we report the first observation of sequence-dependent dsDNA condensation by divalent alkali cations. Disparate behaviors were found between two repeating sequences with 100% AT content, a poly(A)-poly(T) duplex (AA-TT) and a poly(AT)-poly(TA) duplex (AT-TA). While AT-TA exhibits non-distinguishable behaviors from random-sequence genomic DNA, AA-TT condenses in all divalent alkali ions (Mg2+, Ca2+, Sr2+, and Ba2+). We characterized these interactions experimentally and investigated the underlying principles using all-atom computer simulations. Both experiment and simulation demonstrate that AA-TT condensation is driven by nonspecific ion-DNA interactions, which depend on the structures of ions and DNA surface. Detailed analyses reveal sequence-enhanced major groove binding (SEGB) of point-charged alkali ions as the major difference between AA-TT and AT-TA, which originates from the continuous and close stacking of nucleobase partial charges in AA-TT but not in AT-TA. These SEGB cations elicit attraction via spatial correlations with the phosphate backbone of neighboring helices, reminiscent of the “DNA-zipper” model, which though assumes non-electrostatic cation groove binding a priori. Our study thus presents a distinct molecular mechanism of DNA-DNA interaction in which sequence-directed surface motifs act with abundant divalent alkali cations non-specifically to enact sequence-dependent behaviors. This physical insight allows a renewed understanding of the function of repeating DNA sequences in genome organization and regulation and offers a facile approach for DNA technology to control the assembly process of DNA nanostructures.
Crystal structure and Hirshfeld surface analysis of 4-allyl-2-methoxy-6-nitrophenol
Authors: El Ghallab Yassine , Derfoufi Sanae , Ketatni El Mostafa , Saadi Mohamed , El Ammari Lahcen
Published: February 2020

The asymmetric unit of the title compound, C10H11NO4, which was synthesized via nitration reaction of eugenol (4-allyl-2-methoxyphenol) with a mixture of nitric acid and sulfuric acid, consists of three independent molecules of similar geometry. Each molecule displays an intramolecular hydrogen bond involving the hydroxide and the nitro group forming an S(6) motif. The crystal cohesion is ensured by intermolecular C—H...O hydrogen bonds in addition to π–π stacking interactions between the aromatic rings [centroid–centroid distances = 3.6583 (17)–4.0624 (16) Å]. The Hirshfeld surface analysis and the two-dimensional fingerprint plots show that H...H (39.6%), O...H/H...O (37.7%), C...H/H...C (12.5%) and C...C (4%) are the most important contributors towards the crystal packing.
1,3-Bis(2-oxopropyl)thymine
Authors: Doboszewski Bogdan , Nazarenko Alexander Y. , Soares Fábio da Paixão
Published: February 2020

In the title compound [systematic name: 5-methyl-1,3-bis(2-oxopropyl)pyrimidine-2,4(1H,3H)-dione], C11H14N2O4, the two 2-oxopropyl groups are nearly perpendicular to the planar thymine unit. One methyl group of oxopropyl substituent is disordered. In the crystal, C—H...O interactions help to connect the molecules into (001) layers.
Barrier Lyapunov function and disturbance observer based omnidirectional robust gust response stabilization for multi-control-effectors aircraft
Authors: Liu Jinglong , Wu Zhonghua , Xing Xiaowen , He Qizhi
Published: February 2020

Purpose

The purpose of this paper is to find an omnidirectional robust gust response stabilization (GRS) scheme with anti-disturbance and state-limited features.

Design/methodology/approach

Disturbance observer and barrier Lyapunov techniques, which can, respectively, estimate the lumped disturbances of the dynamic system in real-time and ensure the middle states within some prescribed ranges according to some flight safety indexes.

Findings

In the existing literature, almost all of the GRS controllers are either only for the longitudinal dynamics or only for the latitudinal dynamics. Few studies have considered the gust response alleviation problem with omnidirectional wind disturbance and full aircraft model.

Originality/value

This paper proposes a fresh scheme to deal with a more holistic GRS problem; the disturbance observer based (DOB) barrier Lyapunov backstepping longitudinal controller has been put forward; DOB nonlinear dynamic inversion to handle the multi-input-multi-output lateral dynamics; and to closely connect the two loops of the latitudinal dynamics, a manipulating variable conversion method is proposed.
Evaluation of variable pitot inlet concepts for transonic and supersonic civil aviation
Authors: Kazula Stefan , Höschler Klaus
Published: February 2020

Purpose

This paper aims to describe the selection of the ideal variable inlet concept group by using results of aerodynamic investigations, system safety analyses and integration studies.

Design/methodology/approach

Aerodynamic and functional inlet requirements are explained and variable inlet concept groups are introduced. The concept evaluation by means of a weighted point rating is presented. The respective concept groups are analysed and evaluated regarding economic, functional and safety requirements.

Findings

By means of this evaluation, the concept group that adjusts the inlet geometry by rigid segment repositioning is identified as most suitable concept group.

Originality/value

The early selection of the most suitable concept group enables more detailed subsequent concept investigations, potentially enabling the technology of variable inlets for future commercial aircraft.
Subjective well-being of people with ASD in Japan
Authors: Kojima Michio
Published: February 2020

Purpose

The purpose of this paper is to investigate developmental changes and factors affecting subjective well-being (SWB) of people with autism spectrum disorders (ASDs) in Japan.

Design/methodology/approach

Questionnaires were distributed to participants (n = 87) and interviews(n = 33) were conducted to investigate factors affecting SWB.

Findings

This study suggested that the SWB of people with ASD might be closely correlated with their self-esteem. Moreover, high school and university students have negative feelings such as anxiety and worries that affected their SWB, whereas working adults have positive feelings and thinking that influenced their SWB. Furthermore, hobbies were the source of happiness for people with ASD.

Originality/value

This study suggests the factors affecting SWB of people with ASD.
High quality factor fractal inductor with complementary split-ring array inclusion
Authors: Padavala Akhendra Kumar , Akondi Narayana Kiran , Nistala Bheema Rao
Published: February 2020

Purpose

This paper aims to present an efficient method to improve quality factor of printed fractal inductors based on electromagnetic band-gap (EBG) surface.

Design/methodology/approach

Hilbert fractal inductor is designed and simulated using high-frequency structural simulator. To improve the quality factor, an EBG surface underneath the inductor is incorporated without any degradation in inductance value.

Findings

The proposed inductor and Q factor are measured based on well-known three-dimensional simulator, and the results are compared experimentally.

Practical implications

The proposed method was able to significantly decrease the noise with increase in the speed of radio frequency and sensor-integrated circuit design.

Originality/value

Fractal inductor is designed and simulated with and without EBG surfaces. The measurement of printed circuit board prototypes demonstrates that the inclusion of split-ring array as EBG surface increases the quality factor by 90 per cent over standard fractal inductor of the same dimensions with a small degradation in inductance value and is capable of operating up to 2.4 GHz frequency range.
Reduction of central-line-associated bloodstream infection (CLABSI) in resource limited, nonintensive care unit (ICU) settings
Authors: Poh Kok Wei , Ngan Cheng Huong , Wong Ji Yin , Ng Tiang Koi , Mohd Noor Nadiah
Published: February 2020

Purpose

There was limited study available on successful intervention for central-line-associated bloodstream infection (CLABSI) done at nonintensive care unit (ICU) and resources-limited setting. The objective of this study was to design, implement and evaluate a strategy to reduce CLABSI rate in non-ICU settings at general medical wards of Hospital Tuanku Ja'afar Seremban.

Design/methodology/approach

Preinterventional study was conducted in one-month period of January 2019, followed by intervention period from February to March 2019. Postintervention study was conducted from April to July 2019. The CLABSI rates were compared between pre and postintervention periods. A multifaceted intervention bundle was implemented, which comprised (1) educational program for healthcare workers, (2) weekly audit and feedback and (3) implementation of central line bundle of care.

Findings

There was a significant overall reduction of CLABSI rate between preintervention and postintervention period [incidence rate ratio (IRR) of 0.06 (95 percent CI, 0.01–0.33;P = 0.001)].

Practical implications

CLABSI rates were reduced by a multifaceted intervention bundle, even in non-ICU and resource-limited setting. This includes a preinterventional study to identify the risk factors followed by a local adaption of the recommended care bundles. This study recommends resources-limited hospitals to design a strategy that is suitable for their own local setting to reduce CLABSI.

Originality/value

This study demonstrated the feasibility of a multifaceted intervention bundle that was locally adapted with an evidence-based approach to reduce CLABSI rate in non-ICU and resource-limited setting.
Pension plan funding and market value of the firm: the Portuguese case
Authors: Garcia Maria Teresa Medeiros , Domingos José Amílcar Neves
Published: February 2020

Purpose

The objective of the paper is to test the existence of a direct effect between the funding level of a firm's pension fund and its respective market price in Portugal, from 2010 to 2015, using a selected sample of Portuguese Stock Index (PSI Geral) firms. Although this relationship has been contemplated in the literature, especially in the United States and the United Kingdom, there is no finding concerning Portugal. The study of pension assets and obligations is of particular importance to investors and market makers alike.

Design/methodology/approach

The paper utilizes two distinct methods – a cross-sectional model and a variable-effect event study – to assess the hypothesis that an increase in pension deficit is reflected in the market value of a firm by a decrease of equal magnitude.

Findings

This paper finds that a firm's market value is not reduced by an increase in pension deficit and that pension liabilities are already integrated in corporate debt. These results suggest that shareholders fail to take into account occupational pension plan funding status when valuing a firm in such a way that contrasts with the normal evaluation of debt.

Originality/value

To the best of the authors' knowledge, this is the first attempt to examine this relationship in Portugal.
Comprehensive moderated mediation model of potential appraisal of employees
Authors: Mittal Shashank
Published: February 2020

Purpose

Potential appraisal is the foremost indicator of employee's readiness to take higher responsibilities and used for multiple purposes in promotion, human resource development including training and development needs of employees. This study examines how construal level as psychological difference among employees (holistic–analytic differential in preference of thinking for various action domains among individuals) and meaningfulness of work is related to their readiness for development and responsibility. Combining meaning of work literature and cognitive psychology, the moderated mediation model is formed to examine the psychological process and social boundary conditions in the relationship between construal level and potential appraisal of employees.

Design/methodology/approach

Data were collected from 1,494 working executives and their 297 reporting managers across companies operating in an industrial cluster situated in India. The proposed model considered “experienced meaningfulness” as mediator and contextual factors of psychological empowerment and supervisor feedback as moderators.

Findings

Using multi-variate analysis and after controlling for industry type and experience, supervisor potential appraisal ratings of employees are found to be statistically related to construal level, and this relationship is found to be partially mediated by “experienced meaningfulness” of work. Further, contextual factors are found to be significant as moderators.

Originality/value

By bringing the subjective interpretation of different aspects of meaning of work from work design literature to examine its role in relationship between aspects of cognitive psychology and potential appraisal of employees, this study bridges the gap between cognitive psychology of development, meaning of work literature and HRD literature. Further implications for academic literature and managers are discussed.
Does leader humor style matter and to whom?
Authors: Neves Pedro , Karagonlar Gökhan
Published: February 2020

Purpose

The interest on leader humor styles is recent. By applying a trustworthiness framework, the authors examine (1) how leader humor styles contribute to performance and deviance via trust in the supervisor and (2) who benefits/suffers the most from different leader humor styles.

Design/methodology/approach

The authors tested their hypotheses in a sample of 428 employee–supervisor dyads from 19 organizations operating in the services sector.

Findings

Affiliative and self-enhancing leader humor styles are particularly beneficial for employees with low core-self-evaluations, helping them develop trust in the supervisor and consequently improving their performance. An aggressive leader humor style, via decreased trust in the supervisor, reduces performance, regardless of employees' core self-evaluations. Self-enhancing and self-defeating leader humor styles also present significant relationships with organizational deviance.

Research limitations/implications

Limitations include the cross-sectional design and the limited number of mechanisms examined.

Practical implications

Organizations need to train leaders in the use of humor and develop a culture where beneficial humor styles are endorsed, while detrimental humor styles are not tolerated.

Originality/value

These findings contribute to the literatures on trust and humor, by showing that the use of humor is not as trivial as one could initially think, particularly for those with low core self-evaluations, and by expanding our knowledge of the mechanisms by which different leader humor styles may influence performance and deviance.
What matters in implementing the factory of the future
Authors: Pessot Elena , Zangiacomi Andrea , Battistella Cinzia , Rocchi Valerie , Sala Alessandro , Sacco Marco
Published: February 2020

Purpose

This paper aims to study the extent of the transformation of European manufacturing companies towards the factory of the future (FoF) and related concepts, e.g. Industry 4.0 and digitalisation.

Design/methodology/approach

A qualitative survey design was used to investigate the areas, patterns and elements for implementing FoF. A total of 92 responses from manufacturing firms of Alpine regions were collected and analysed, followed by in-depth interviews with a subset of respondents to identify common challenges, drivers and opportunities for the transformation.

Findings

Manufacturing companies are gaining awareness on their needs and gaps in the FoF path, the implications on business strategy and the rates of innovation and technology adoption. Nevertheless, they still need to shape their organisational structures (e.g. from highly centralised to more collaborative ones) and nurture their managerial capabilities in operations and supply chain management, and customer relationships, only partially based on FoF technologies.

Research limitations/implications

This study aims to contribute to recent literature and practice of FoF (and related concepts) by depicting a picture of the possible areas of intervention, main issues and gaps (especially in terms of skills, supply chain and customer relationships) of manufacturing companies in their digital transformation. The qualitative research design and its scope represent the main limitations.

Originality/value

This paper provides a systemic overview for FoF by encompassing the technological, strategic, managerial and organisational perspectives of digitalisation in manufacturing and integrating the insights from a multi-sectorial and multi-dimensional analysis.
Family SMEs’ survival: the role of owner family and corporate social responsibility
Authors: Ahmad Shabir , Siddiqui Kamran Ahmed , AboAlsamh Hoda Mahmoud
Published: February 2020

Purpose

The purpose of this paper is to examine the impact of owner family involvement in business on sustainable survival of family small-to-medium enterprises (SMEs) and to empirically validate the intervening role of corporate social responsibility (CSR).

Design/methodology/approach

The authors analyze data from 489 owner and nonowner executives of 150 family SMEs using PLS-SEM (Partial Least Square–Structural Equation Modeling).

Findings

The authors found evidence that family involvement in business positively impacts the sustainable survival of family SMEs while corporate social responsibility partially mediates this relationship. Apart from effective family involvement in business, active involvement in social causes enhances a firm's ability to survive longer.

Research limitations/implications

This study was conducted in a geographic context and data were collected from family-managed and controlled firms. Further research is needed to generalize the findings to all types of family firms in the global context. In an Islamic society, family firms need to invest in social causes, human development, and environmental sustainability through zakat, sadaqat, and donations.

Practical implications

The findings imply that family firms require stakeholder-centric competitive strategies and socially responsible behavior along with effective family control, commitment, enrichment, and successful succession since the path to sustainable survival goes through CSR.

Originality/value

Survival is the biggest challenge facing family SMEs forcing them to achieve the ability to sustain longer. Rooted in transaction cost economics (TCE) theory of the family firm and stakeholder theory, this paper validates an integrative model for family SMEs' sustainable survival.
Elevated atmospheric CO2 suppresses jasmonate and silicon‐based defences without affecting herbivores
Authors: Hall Casey R. , Mikhael Meena , Hartley Susan E. , Johnson Scott N.
Published: February 2020

Elevated atmospheric CO2 (eCO2) not only increases plant growth but can also interfere with defence against insect herbivory through the disruption of the jasmonic acid (JA) pathway. Silicon (Si) plays an important role in plant stress tolerance and resistance to herbivory, particularly in grasses, many of which accumulate high amounts of Si. Activation of the JA pathway has been reported to stimulate Si uptake, while Si supplementation can alter both constitutive and induced phytohormone levels. A reduction in JA concentration under eCO2 has the potential to reduce Si uptake in plants.

Using both Si supplemented (Si+) and control (Si−) plants (Brachypodium distachyon) grown under ambient (400 ppm) and elevated (640 ppm) CO2 concentrations, we tested how plant growth, foliar Si concentration and endogenous JA responded to methyl jasmonate (MeJA) application and the subsequent effects on insect herbivore performance (Helicoverpa armigera).

Elevated CO2 reduced Si concentration by 19% and endogenous JA by 70% on average. MeJA significantly increased Si concentration in Si+ plants. Si+ plants had higher baseline JA levels compared to Si− plants under control conditions (i.e. no stress), however, when plants were chemically induced with MeJA, the JA response was on average 84% lower in Si+ plants compared to Si− plants. Plants without MeJA treatment showed the opposite response, that is, Si+ plants had higher baseline JA levels compared to Si− plants. Si significantly reduced herbivore consumption and growth rate. Despite eCO2 significantly reducing both Si and endogenous JA, no effect was seen on herbivores feeding on eCO2 plants.

Collectively our results suggest that Si alters the JA response of plants. We show that JA induces Si uptake, however, Si then reduces the JA response of plants under induced stress conditions. However, predicted increases in CO2 levels within this century may significantly reduce Si‐based mechanical defences against herbivory via a reduction of endogenous JA.

A free Plain Language Summary can be found within the Supporting Information of this article.
The Implications of the Political Situation in the UK for Firms: A Bourdieusian Perspective
Authors: Śliwa Martyna , Kerr Ron , Robinson Sarah
Published: February 2020

The political situation in the UK poses unprecedented challenges for firms as well as management and organization studies (MOS) scholars. In this short paper, we encourage MOS researchers to consider the French sociologist Pierre Bourdieu's conceptual framework, in particular, his key concepts of field, capital, habitus and hysteresis, as a lens to analyse the multifaceted implications for firms of the current political circumstances in the UK. We explain how a Bourdieusian perspective can help researchers challenge taken‐for‐granted assumptions about the interconnections between politics and business in the context of Brexit and can assist in generating valuable insights regarding the situation of firms operating in the UK in the context of the present changes in the environment.