bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutagenesis of the Orco Odorant Receptor Co-receptor Impairs Olfactory Function in the Malaria VectorAnopheles coluzzii
Authors: Sun Huahua , Liu Feng , Ye Zi , Baker Adam , Zwiebel Laurence J.
Published: September 2020

Mosquitoes rely heavily on their olfactory systems for host seeking, selection of oviposition sites, and avoiding predators and other environmental dangers. Of these behaviors, the preferential selection of a human blood-meal host drives the vectorial capacity of anthropophilic femaleAnopheles coluzziimosquitoes. Olfactory receptor neurons (ORNs) are dispersed across several appendages on the head and express an obligate odorant receptor co-receptor (Orco) coupled with a “tuning” odorant receptor (OR) to form heteromeric, odor-gated ion channels in the membrane of these neurons. To examine the mechanistic and functional contributions of Orco/OR complexes to the chemosensory processes ofAn. coluzzii, we utilized CRISPR/Cas9 gene editing to create a line of homozygous, Orco-knockout, mutant mosquitoes. As expected,orco-/-ORNs across both adult and larval stages ofAn. coluzziidisplay significantly lower background activity and lack nearly all odor-evoked responses. In addition, blood-meal-seeking, adult female,orco- /-mutant mosquitoes exhibit severely reduced attraction to human- and non-human-derived odors while gravid females are significantly less responsive to established oviposition attractants. These results reinforce observations in other insects that Orco is crucial in maintaining the activity of ORNs. In that light, it significantly influences a range of olfactory-driven behaviors central to the anthropophilic host preference that is critical to the vectorial capacity ofAn. coluzziias a primary vector for human malaria.
Discovery and prioritization of variants and genes for kidney function in >1.2 million individuals
Authors: Stanzick Kira J , Li Yong , Gorski Mathias , Wuttke Matthias , Pattaro Cristian , Köttgen Anna , Stark Klaus J , Heid Iris M , Winkler Thomas W
Published: September 2020

Chronic kidney disease (CKD) has a complex genetic underpinning. Genome-wide association studies (GWAS) of CKD-defining glomerular filtration rate (GFR) have identified hundreds of loci, but prioritization of variants and genes is challenging. To expand and refine GWAS discovery, we meta-analyzed GWAS data for creatinine-based estimated GFR (eGFRcrea) from the Chronic Kidney Disease Genetics Consortium (CKDGen, n=765,348, trans-ethnic) and UK Biobank (UKB, n=436,581, Europeans). The results (i) extend the number of eGFRcrea loci (424 loci; 201 novel; 8.9% eGFRcrea variance explained by 634 independent signals); (ii) improve fine-mapping resolution (138 99% credible sets with ≤5 variants, 44 single-variant sets); (iii) ascertain likely kidney function relevance for 343 loci (consistent association with alternative biomarkers); and (iv) highlight 34 genes with strong evidence by a systematic Gene PrioritiSation (GPS). We provide a sortable, searchable and customizable GPS tool to navigate through thein silicofunctional evidence and select relevant targets for functional investigations.
Hydrogen-deuterium exchange reveals a dynamic DNA binding map of Replication Protein A
Authors: Ahmad Faiz , Patterson Angela , Deveryshetty Jaigeeth , Mattice Jenna , Pokhrel Nilisha , Bothner Brian , Antony Edwin
Published: September 2020

Replication Protein A (RPA) binds to single-stranded DNA (ssDNA) and interacts with over three dozen enzymes and serves as a recruitment hub to coordinate most DNA metabolic processes including DNA replication, repair, and recombination. RPA binds ssDNA utilizing six oligosaccharide/oligonucleotide binding (OB) domains within a heterotrimeric complex of RPA70, RPA32 and RPA14 subunits. Based on their DNA binding affinities they are classified as high versus low-affinity DNA binding domains (DBDs). However, recent evidence suggests that the DNA-binding dynamics of DBDs better define their roles. Utilizing hydrogen-deuterium exchange mass spectrometry (HDX-MS) we assessed the contacts and dynamics of the individual domains of human RPA to determine the landscape of conformational changes upon binding to ssDNA. As expected, ssDNA interacts with the major DBDs (A, B, C, and D). However, DBD-A and DBD-B are dynamic and do not show robust DNA-dependent protection. DBD-C displays the most extensive changes in HDX, suggesting a major role in stabilizing RPA on ssDNA. DNA-dependent HDX kinetics are also captured for DBD-D and DBD-E. Slower allosteric changes transpire in the protein-protein interaction domains and the linker regions. We propose a dynamics-based DNA binding model for RPA utilizing a dynamic half and a less-dynamic half.
TEA-seq: a trimodal assay for integrated single cell measurement of transcription, epitopes, and chromatin accessibility
Authors: Swanson Elliott , Lord Cara , Reading Julian , Heubeck Alexander T. , Savage Adam K. , Green Richard , Li Xiao-jun , Torgerson Troy R. , Bumol Thomas F. , Graybuck Lucas T. , Skene Peter J.
Published: September 2020

Single-cell measurements of cellular characteristics have been instrumental in understanding the heterogeneous pathways that drive differentiation, cellular responses to extracellular signals, and human disease states. scATAC-seq has been particularly challenging due to the large size of the human genome and processing artefacts resulting from DNA damage that are an inherent source of background signal. Downstream analysis and integration of scATAC-seq with other single-cell assays is complicated by the lack of clear phenotypic information linking chromatin state and cell type. Using the heterogeneous mixture of cells in human peripheral blood as a test case, we developed a novel scATAC-seq workflow that increases the signal-to-noise ratio and allows simultaneous measurement of cell surface markers: Integrated Cellular Indexing of Chromatin Landscape and Epitopes (ICICLE-seq). We extended this approach using a droplet-based multiomics platform to develop a trimodal assay to simultaneously measureTranscriptomic state (scRNA-seq), cell surfaceEpitopes, and chromatinAccessibility (scATAC-seq) from thousands of single cells, which we term TEA-seq. Together, these multimodal single-cell assays provide a novel toolkit to identify type-specific gene regulation and expression grounded in phenotypically defined cell types.
Diagnosing Cognitive Disorders in Older Adults with Temporal Lobe Epilepsy
Authors: Reyes Anny , Kaestner Erik , Edmonds Emily C. , Macari Anna Christina , Wang Zhong Irene , Drane Daniel L. , Punia Vineet , Busch Robyn M. , Hermann Bruce P. , McDonald Carrie R. ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: September 2020

Objective

To characterize the nature and prevalence of cognitive disorders in older adults with temporal lobe epilepsy (TLE) and compare their cognitive profiles to non-epileptic patients with mild cognitive impairment (i.e.,classicMCI; cMCI).

Methods

Seventy-eight older patients with TLE, 77 cMCI, and 69 normal aging controls (NAC), all 55-80 years, completed neuropsychological measures of memory, language, executive function and processing speed. An actuarial neuropsychological method designed to diagnose MCI was applied to individual patients to identify older adults with TLE who met diagnostic criteria for MCI (TLE-MCI). A linear classifier was performed to evaluate how well the diagnostic criteria differentiated patients with TLE-MCI from cMCI. In TLE, the contribution of epilepsy-related and vascular risk factors to cognitive impairment was evaluated using multiple regression.

Results

Forty-three TLE patients (60%) met criteria for TLE-MCI, demonstrating marked deficits in both memory and language. A classification model between TLE-MCI and cMCI correctly classified 81.1% (90.6% specificity, 61.3% sensitivity) of the cohort based on neuropsychological scores. Whereas TLE-MCI showed greater deficits in language relative to cMCI, patients with cMCI showed greater rapid forgetting on memory measures. Both epilepsy-related risk factors and the presence of leukoaraiosis on MRI contributed to impairment profiles in TLE-MCI.

Interpretation

Approximately 60% of older adults with TLE meet diagnostic criteria for a cognitive disorder associated with aging (i.e., MCI). The TLE-MCI phenotype may be secondary to an accumulation of epilepsy and vascular risk factors, signal the onset of a neurodegenerative disease, or represent a combination of both factors.
Impact of exercise training on sarcopenia associated with non-alcoholic fatty liver disease (NAFLD) in humans: A systematic review and meta-analysis
Authors: Gonzalez Andrea , Valero-Breton Mayalen , Huerta-Salgado Camila , Achiardi Oscar , Simon Felipe , Cabello-Verrugio Claudio
Published: September 2020

Objective

To conduct a systematic review and meta-analyses to assess the efficacy of physical exercise on strength, muscle mass and physical function in adult patients with non-alcoholic fatty liver disease (NAFLD).

Design

We conducted a systematic review and meta-analysis of seven studies to investigate the effect of exercise training interventions in muscle strength, muscle mass and physical performance.

Data sources

We identified relevant randomised controlled trials (RCT) in electronic databases (PubMed, CINAHL and Scopus).

Eligibility criteria

We selected seven RCTs from 66 screened studies. The inclusion criteria were peer-reviewed and English writing articles that included adult patients with liver disease of non-alcoholic origin, applied resistance training, endurance training or both, and assayed at least one variable of sarcopenia.

Results

Physical performance criterion improved in the exercise groups (mean differences [MD] 8.26 mL/Kg*min [95% CI 5.27 to 11.24 mL/Kg*min], p < 0.0001) versus the control groups; muscle mass, determined as lean body mass (LBM), showed no evidence of the beneficial effects of exercise versus the control groups (MD 1.01 Kg [95% CI −1.78 to 3.80 Kg], p = 0.48); we did not include muscle strength, as none of the selected studies evaluated it.

Summary/conclusion

Exercise training is a useful intervention strategy to treat sarcopenia in patients with NAFLD; it increases their physical performance in the form of aerobic capacity but does not affect LBM. Future research should include muscle strength assessments and resistance training to evaluate the effects of exercise training on sarcopenia in NAFLD patients.

PROSPERO reference number CRD42020191471
Development and Validation of the Patient History COVID-19 (PH-Covid19) Scoring System: A Multivariable Prediction Model of Death in Mexican Patients with COVID-19
Authors: Mancilla-Galindo J. , Vera-Zertuche J. M. , Navarro-Cruz A. R. , Segura-Badilla O. , Reyes-Velázquez G. , Tepepa-López F. J. , Aguilar-Alonso P. , de J. Vidal-Mayo J. , Kammar-García A.
Published: September 2020

We sought to develop and validate a multivariable prediction model of death in Mexican patients with COVID-19, by using demographic and patient history predictors. We conducted a national retrospective cohort in two different sets of patients from the Mexican COVID-19 Epidemiologic Surveillance Study. To develop the model, we included 264,026 patients tested for SARS-CoV-2 between February 28 and May 30, 2020. To validate the model, 592,160 patients studied between June 1 and July 23, 2020 were included. Patients with a positive RT-PCR for SARS-CoV-2 and complete unduplicated data were eligible. Demographic and patient history variables were analyzed through Multivariable Cox regression models to evaluate predictors to be included in the prognostic scoring system called PH-Covid19. 83,779 patients were included to develop the model; 100,000, to validate the model. Eight predictors (age, sex, diabetes, COPD, immunosuppression, hypertension, obesity, and CKD) were included in the PH-Covid19 scoring system (range of values: −2 to 25 points). The predictive model has a discrimination of death of 0.8 (95%CI:0.796-0.804). The PH-Covid19 scoring system was developed and validated in Mexican patients to aid clinicians to stratify patients with COVID-19 at risk of fatal outcomes, allowing for better and efficient use of resources.
Quantifying mechanical loading and elastic strain energy of the human Achilles tendon during walking and running
Authors: Kharazi Mohamadreza , Bohm Sebastian , Theodorakis Christos , Mersmann Falk , Arampatzis Adamantios
Published: September 2020

The purpose of the current study was to assess Achilles tendon (AT) mechanical loading and strain energy during locomotion using a new in vivo approach for measuring AT length that considers the AT curve-path shape. Eleven participants walked at 1.4 m/s and ran at 2.5 m/s and 3.5 m/s on a treadmill. AT length, defined as the distance between its origin at the gastrocnemius medialis myotendinous junction (MTJ) and the calcaneal insertion, was determined experimentally by integrating kinematics and ultrasound analysis. Small foil markers were placed on the skin covering the AT path from the origin to the insertion, and the MTJ, tracked using ultrasonography, was projected to the reconstructed skin to account for their misalignment. Skin-to-bone displacements were assessed during a passive rotation (5 °/s) of the ankle joint and considered in the calculation of AT length. Force and strain energy of the AT during locomotion were calculated by fitting a quadratic function to the experimentally measured tendon force-length curve obtained from maximum voluntary isometric contractions. Maximum AT strain and force were affected by speed (p<0.05, ranging from 4.0 to 4.9% strain and 1.989 to 2.556 kN), yet insufficient in magnitude to be considered an effective stimulus for tendon adaptation. Further, we found a recoil of elastic strain energy at the beginning of the stance phase of running (70-77 ms after touch down) between 1.7 ±0.6 and 1.9 ±1.1 J, which might be functionally relevant for running efficiency.

Summary statement

A new accurate in vivo approach to assess Achilles tendon strain, force and strain energy during locomotion.
Methionine synthase supports tumor tetrahydrofolate pools
Authors: Wang Joshua Z. , Ghergurovich Jonathan M. , Yang Lifeng , Rabinowitz Joshua D.
Published: September 2020

Mammalian cells require activated folates to generate nucleotides for growth and division. The most abundant circulating folate species is 5-methyl tetrahydrofolate (5-methyl-THF), which is used to synthesize methionine from homocysteine via the cobalamin-dependent enzyme methionine synthase (MTR). Cobalamin deficiency traps folates as 5-methyl-THF. Here, we show using isotope tracing that methionine synthase is only a minor source of methionine in cell culture, tissues, or xenografted tumors. Instead, methionine synthase is required for cells to avoid folate trapping and assimilate 5-methyl-THF into other folate species. Under conditions of physiological extracellular folates, genetic MTR knockout in tumor cells leads to folate trapping, purine synthesis stalling, nucleotide depletion, and impaired growth in cell culture and as xenografts. These defects are rescued by free folate but not one-carbon unit supplementation. Thus, MTR plays a crucial role in liberating tetrahydrofolate for use in one-carbon metabolism.
Kynurenic acid underlies sex-specific immune responses to COVID-19
Authors: Cai Yuping , Kim Daniel J. , Takahashi Takehiro , Broadhurst David I. , Ma Shuangge , Rattray Nicholas J.W. , Casanovas-Massana Arnau , Israelow Benjamin , Klein Jon , Lucas Carolina , Mao Tianyang , Moore Adam J. , Muenker M. Catherine , Oh Jieun , Silva Julio , Wong Patrick ,   Yale IMPACT Research team, Ko Albert I. , Khan Sajid A. , Iwasaki Akiko , Johnson Caroline H.
Published: September 2020

Coronavirus disease-2019 (COVID-19) has poorer clinical outcomes in males compared to females, and immune responses underlie these sex-related differences in disease trajectory. As immune responses are in part regulated by metabolites, we examined whether the serum metabolome has sex-specificity for immune responses in COVID-19. In males with COVID-19, kynurenic acid (KA) and a high KA to kynurenine (K) ratio was positively correlated with age, inflammatory cytokines, and chemokines and was negatively correlated with T cell responses, revealing that KA production is linked to immune responses in males. Males that clinically deteriorated had a higher KA:K ratio than those that stabilized. In females with COVID-19, this ratio positively correlated with T cell responses and did not correlate with age or clinical severity. KA is known to inhibit glutamate release, and we observed that serum glutamate is lower in patients that deteriorate from COVID-19 compared to those that stabilize, and correlates with immune responses. Analysis of Genotype-Tissue Expression (GTEx) data revealed that expression of kynurenine aminotransferase, which regulates KA production, correlates most strongly with cytokine levels and aryl hydrocarbon receptor activation in older males. This study reveals that KA has a sex-specific link to immune responses and clinical outcomes, in COVID-19 infection.
The impact of mobility restriction measures on the reproduction index of Covid-19 in the city of Queretaro, Mexico
Authors: Orozco Oscar San Roman , Orozco Santiago Agraz , Alvarez Isidro A Gutierrez , Radaios Vasiliki
Published: September 2020

An observational study based on official data (CONACYT and Ministry of Health) was carried out in which the effective reproduction index R(e) and the reproduction index R0 are compared with the mobility presented by Google. Additionally, an overview of the development of the pandemic in Querétaro, Mexico. Highlights key events; such as the main government interventions and social factors that could affect society’s behavior.

A positive relationship is observed between Re, R0, and the levels of mobility presented by Google. This indicates that an increase in mobility is associated with the transmission of SARSCoV-2. In February, a significant decrease in mobility is observed, which lasts until approximately May 1st. This period corresponds to an R0 and R(e) between 1.17 and 1.87. After May 1st, there is a sustained increase in mobility levels. And, as of May 16, the effective reproduction index R (e) and the reproduction index R0 begin to increase. This is expected as it reflects the delay between the infection and the diagnosis of COVID-19. The R0 and R (e) increase from 1.45 on May 16 to 3.59 on July 5. According to the baseline of normal mobility levels, an increase from −49.6% on May 1st, to −20.6% on July 5 was observed.

Based on these data, we conclude that the relaxation of restrictive mobility measures should be reconsidered. Despite this, mobility restrictions must not be a unique mitigation strategy for controlling the Reproductive Index. A comprehensive approach is needed, which generates socio-behavioral changes that allow a further reduction in reproductive rates.

Key Messages

There is a positive correlation between the reproductive number (R0) and the effective reproductive index (Re) of SARS-CoV-2 and mobility trends in Querétaro, Mexico.

A clear increase in mobility in the population in Queretaro, Mexico is associated with an increase in the rate of transmission of Covid-19.
Learning a force field from small-molecule crystal lattice predictions enables consistent sub-Angstrom protein-ligand docking
Authors: Park Hahnbeom , Zhou Guangfeng , Baek Minkyung , Baker David , DiMaio Frank
Published: September 2020

Accurate and rapid calculation of protein-small molecule interaction energies is critical for computational drug discovery. Because of the large chemical space spanned by drug-like molecules, classical force fields contain thousands of parameters describing atom-pair distance and torsional preferences; each parameter is typically optimized independently on simple representative molecules. Here we describe a new approach in which small-molecule force field parameters are jointly optimized guided by the rich source of information contained within thousands of available small molecule crystal structures. We optimize parameters by requiring that the experimentally determined molecular lattice arrangements have lower energy than all alternative lattice arrangements. Thousands of independent crystal lattice-prediction simulations were run on each of 1,386 small molecule crystal structures, and energy function parameters of an implicit solvent energy model were optimized so native crystal lattice arrangements had lowest energy. The resulting energy model was implemented in Rosetta, together with a rapid genetic algorithm docking method employing grid based scoring and receptor flexibility. The success rate of bound structure recapitulation in cross-docking on 1,112 complexes was improved by more than 10% over previously published methods, with solutions within <1 Å in over half of the cases. Our results demonstrate that small molecule crystal structures are a rich source of information for systematically improving computational drug discovery.
Characterizing mechanics of membrane tether from relaxation curve obtained by optical tweezers
Authors: Li Xuanling , Song Xiaoyu , Li Yinmei , Li Ming , Wang Haowei
Published: September 2020

Optical tweezers is a powerful tool in the study of membrane tension. Comparing to pulling out an entire membrane tether at one time, the step-like method is more efficient because multiple relaxation curves can be obtained from one membrane tether. However, there is few proper models that describe relaxation curves to characterize mechanical properties of cell membrane. Here we established a model to describe the relaxation curve of HeLa cells based on the relationship between membrane tether diameter and tensions. We obtained effective viscosities and static tensions by fitting relaxation curves to our model. We noticed the delicate structure of relaxation curves contains information of cell skeleton changes and protein diffusion. Our study paved a novel pathway to characterize the dynamics and mechanics of cell membrane.
The translation attenuating arginine-rich sequence in the extended signal peptide of the protein-tyrosine phosphatase PTPRJ/DEP1 is conserved in mammals
Authors: Karagyozov Luchezar , Grozdanov Petar , Böhmer Frank-D.
Published: September 2020

The signal peptides, present at the N-terminus of many proteins, guide the proteins into cell membranes. In some proteins, the signal peptide contains an extended N-terminal region and a recessed hydrophobic signal sequence. Previously, it was demonstrated that the N-terminally extended signal peptide of the humanPTPRJcontains a cluster of arginine residues, which attenuates translation. The analysis of the orthologous sequences revealed that this sequence is highly conserved among mammals. ThePTPRJtranscripts in placentals, marsupials, and monotremes encode a stretch of 10 – 14 arginine residues, positioned 11-12 codons downstream of the initiating AUG. The remarkable conservation of the repeated arginine residues in thePTPRJsignal peptides points to their key role. Further, the presence of an arginine cluster in the extended signal peptides of other proteins (E3 ubiquitin-protein ligase, NOTCH3) is noted and indicates a more general importance of this cis-acting mechanism of translational suppression.
Response of land use change and ecosystem services based on different functional scenarios: Case study of Nanjing
Authors: Wang Ziyi , wang Yu , Zhang Jingxiang , Sun Dongqi , Zhou Zihang
Published: September 2020

Land Use/Land Cover Change (LUCC) is one of the important reasons for the change of ecosystem services (ESs). Due to the uncertainty of future development policies and the complexity of LUCC, assessing the impact of future urban sprawl on ecosystem services remains challenging. We simulated the effect of urban land-use change on ESs on the basis of different functional scenarios, which is of important value to urban land-use planning and ESs protection. In our study, we designed three scenarios: Production function priority scenario (PFP scenario)、 Living function priority scenario (LFP scenario)、 Ecological function priority scenario (EFP Scenario). And we used the GeoSOS-FLUS software to realize visualization. Based on invest model, we evaluated five types of ESs: carbon storage, warter yield, habitat quality, water purification and soil conservation. Research showed that from 2000 to 2015, carbon storage, habitat quality and water production in Nanjing decreased significantly, soil conservation increased slightly, and the performance of the two indicators for water purification was not consistent. From different scenarios, carbon storage and habitat quality were the highest in EFP scenario, water yield was the highest in PFP scenario and soil conservation was the highest in LFP scenario. We analyzed the trade-offs among various ESs, found that the change of land-use types in cities does not fundamentally change the trade-offs among various ESs. We believed that the determination of the main function of LUCC was the first condition to judge the applicability of scenario, and the scenario simulation which integrated the main function of the city could provide more references for the related research.
Microbial activated mineral weathering and cementation as precursors to hardpan formation and heavy metal encapsulation in sulfidic tailings
Authors: Liu Yunjia , Wu Songlin , Southam Gordon , Chan Ting-Shan , Lu Ying-Rui , Paterson David J. , Huang Longbin
Published: September 2020

Extensive mineral weathering and formation of large amounts of Fe-rich secondary mineral gels have been identified as precursors critical to forming massive hardpan caps in the surface layers of sulfidic tailings. However, how to initiate and accelerate these precursor processes remains to be established before developing this hardpan-based novel method to rehabilitate sulfidic tailings landscapes. In a 5-month microcosm experiment, the present study has demonstrated the concept of bio-engineering sulfidic tailings by inoculating Fe/S-oxidizing bacterial consortium to accelerate the weathering of sulfides and other Si-rich minerals for mineral gels formation. Synchrotron-based X-ray absorption fine structure spectroscopy (XAFS) demonstrated that the weathering of pyrite and biotite-like minerals was rapidly accelerated by the presence of Fe/S-oxidizing bacterial consortium. The microbial process and associated mineral transformation led to the formation of critical precursor mineral gels,i.e., jarosite-like minerals, as indicators of the onset of hardpan formation. In the meantime, the labile Zn liberated in the weathering was encapsulated in the jarosite-like minerals as revealed by X-ray fluorescence microscopy (XFM). This concept-proven bio-engineering process is ready to be scaled up in further studies under field conditions to develop an alternative hardpan-based method to cover and rehabilitate sulfidic tailing landscapes.

TOC Art
Ptychography at the Linac Coherent Light Source in a parasitic geometry
Authors: Pound Benjamin A. , Mertes Kevin M. , Carr Adra V. , Seaberg Matthew H. , Hunter Mark S. , Ward William C. , Hunter James F. , Sweeney Christine M. , Sewell Christopher M. , Weisse-Bernstein Nina R. , Baldwin J. Kevin S. , Sandberg Richard L.
Published: September 2020

X-ray free-electron lasers (FELs) are being recognized as a powerful tool in an ever-increasing number of research fields, but are very limited as to the number of experiments that they can support. This work shows that more beamtime could be made available by using `parasitic' geometries, where a secondary experiment uses the X-ray beam that the primary experiment does not utilize. The first successful ptychography experiment, a scanning coherent diffractive imaging technique, in a parasitic geometry at an X-ray FEL is demonstrated. Utilizing the CXI hutch at the Linac Coherent Light Source (LCLS), it is shown that the obtained data are of high quality and that characterizing the beam using ptychography can be much faster than traditional imprinting methods.
Structures of three disubstituted [13]-macrodilactones reveal effects of substitution on macrocycle conformation
Authors: Rutledge Kelli M. , Griesbach Caleb , Mercado Brandon Q. , Peczuh Mark W.
Published: September 2020

The synthesis and crystal structures of three new disubstituted [13]-macrodilactones, namely, trans-4,8-dimethyl-1,10-dioxacyclotridec-5-ene-2,9-dione, C13H20O4, I, cis-4-(4-bromophenyl)-13-methyl-1,10-dioxacyclotridec-5-ene-2,9-dione C18H21BrO4, II, and trans-11-methyl-4-phenyl-1,10-dioxacyclotridec-5-ene-2,9-dione, C18H22O4, III, are reported and their conformations are put in the context of other [13]-macrodilactone structures reported previously. Together, they show that the number, location, and relative disposition of groups attached at the termini of planar units of the [13]-macrodilactones subtly influence their aspect ratios.
Ethyl 1H-indole-2-carboxylate
Authors: Lynch Will E. , Whitlock Christine R. , Padgett Clifford W.
Published: September 2020

Our work in the area of synthesis of tris indole compounds as a potential chelator led to the synthesis and crystallization of ethyl 1H-indole-2-carboxylate, C11H11NO2, an indole that was synthesized by the thionyl chloride reaction of 1H-indole-2-carboxylic acid, followed by dissolution in ethanol. The molecular packing exhibits a herringbone pattern with the zigzag running along the b-axis direction; the compound crystallizes as a hydrogen-bonded dimer resulting from O...H—N hydrogen bonds, between the indole N—H group and the keto oxygen atom, which build centrosymmetric R
2
2(10) ring motifs in the crystal.
Financial constraints and speed of working capital adjustment
Authors: Ahangar Nufazil
Published: September 2020

Purpose

The study examines the existence of target level of working capital and the speed of adjustment toward the target for eight manufacturing sectors of Indian economy. In addition, this study examines the impact of financial constraints on the speed of adjustment.

Design/methodology/approach

This study is based on secondary financial data of 1936 Indian manufacturing companies from eight sectors for a period of 18 years (2000–2018). This study employs two-step GMM techniques to arrive at results.

Findings

Results of the study confirm that firms do have target working capital, but the speed of adjustment from the current level of working capital to the target working capital is slow, and the speed of adjustment varies across sub-sectors. Moreover, we found that firms that are likely to be less constrained adjust their working capital quickly compared to firms facing high financial constraints.

Originality/value

This study contributes to working capital management literature by examining the speed with which the firms move toward their target and also the impact of financial constraints on the speed of adjustment across eight manufacturing sectors of Indian economy. Further, the study examines the impact of financial constraints on the speed of adjustment.
The interactive effects of religiosity and recognition in increasing donation
Authors: Septianto Felix , Tjiptono Fandy , Paramita Widya , Chiew Tung Moi
Published: September 2020

Purpose

The purpose of this paper is to examine a three-way interaction between the two motivational orientations of religiosity (i.e. intrinsic and extrinsic) and recognition (in this study, an explicit expectation that behavior is recognized) on charitable behavior. Further, drawing upon the evolutionary psychology perspective, the status motive is predicted to mediate the predicted effects.

Design/methodology/approach

Three experimental studies were conducted using a 2 (intrinsic religiosity: low/high; measured) × 2 (extrinsic religiosity: low/high; measured) × 2 (recognition: yes/no; manipulated) between-subjects design to examine the predicted effects on likelihood to donate and donation allocations in two Asian countries, namely, Indonesia and Malaysia.

Findings

The results show that recognition increases charitable behavior among consumers with a high level of extrinsic religiosity but low level of intrinsic religiosity (Studies 1a, 1b and 2). Further, a status motive mediates the predicted effects (Study 2).

Research limitations/implications

The present research provides a novel perspective on how marketers can purposively use recognition in charitable advertising to encourage charitable behavior among religious consumers – but only in Asia.

Practical implications

This paper presents the case for how a non-profit organization can develop charitable advertising for disaster relief in Indonesia (Studies 1a and 1b) and Malaysia (Study 2). The findings of this research could potentially be extended to other organizations in Asia or other countries where religiosity places an important role in consumer behavior.

Originality/value

This research shows the interactive effect between extrinsic religiosity, intrinsic religiosity and recognition can increase charitable behavior in Asia.
The allure of starting afresh: the effects of mortality-related sadness on the effectiveness of fresh start appeals
Authors: Septianto Felix , Khan Saira , Seo Yuri , Shi Linsong
Published: September 2020

Purpose

This paper aims to examine how mortality-related sadness, as compared to other emotions such as fear, anger and happiness, can leverage the effectiveness of fresh start appeals.

Design/methodology/approach

Drawing upon the consumption-based affect regulation principle, this paper investigates how sadness associated with mortality can elicit the appraisal of irretrievable loss, which subsequently increases the effectiveness of fresh start appeals. These predictions are tested across three experimental studies.

Findings

Findings demonstrate that mortality-related sadness enhances donation allocations (Study 1), willingness to pay (Study 2) and favorable attitudes (Study 3) toward an advertisement promoted with a fresh start appeal. This effect is mediated by an appraisal of irretrievable loss (Studies 1–3). Moreover, the emotion’s effect only emerges among consumers who believe that their emotional experiences are stable (vs malleable) (Study 3).

Research limitations/implications

This paper investigates the effects of negative (vs positive emotions). It would thus be of interest to explore whether different discrete positive emotions may also enhance favorable evaluations of fresh start appeals.

Practical implications

While fresh start appeals have been widely used by marketers and organizations, the extant literature in this area has yet to identify how marketers can leverage the effectiveness of such appeals. This paper highlights how a specific negative emotion can be beneficial to marketers in leveraging the effectiveness of fresh start appeals.

Originality/value

The findings of this research suggest a novel potential strategy for the regulation of sadness. Specifically, consumers experiencing mortality-related sadness show favorable evaluations of fresh start appeals, indicating they are seeking to dissociate themselves from the past.
Investigating the role of mobile payment quality characteristics in the United Arab Emirates: implications for emerging economies
Authors: Mouakket Samar
Published: September 2020

Purpose

This study contributes to the limited and rather fragmented research on mobile payment (m-payment) within a post-adoption context by identifying individual characteristics (personal innovativeness and m-payment self-efficacy) and m-payment quality characteristics (system quality, information quality and service quality) that can influence expectations about performance and effort of this technology. These two outcome expectations may affect user satisfaction with m-payment, which will in turn influence users' continued intention to use this technology.

Design/methodology/approach

A survey was carried out among university students in the United Arab Emirates who have used the m-payment method. Structural equation modeling technique was used to test and analyze both the measurement model and the structural model.

Findings

Individual characteristics are important in establishing users' expectations of the ease of use and usefulness of m-payment. However, of the quality characteristics, only system quality significantly affected users' expectations of the ease of use and usefulness of m-payment.

Originality/value

The findings of this study provide unique insights into the individual and quality characteristics that will eventually lead to continued intention to use m-payment. This will help businesses to develop appropriate marketing strategies to increase adoption and use of m-payment.
Belt and road initiative (BRI) supply chain risks: propositions and model development
Authors: Ram Jiwat , Zhang Zeyang
Published: September 2020

Purpose

Belt and road initiative (BRI) is a transcontinental endeavor strategically connecting supply chains (SCs) and economic infrastructures to ignite business activities and achieve trade benefits. However, the rising global SC failure costs and risks associated with this initiative (owing to unique geopolitical, economic and mega-connectivity involving over 70 countries) necessitate examining BRI SC risks. Yet, research on the subject remains limited, and the purpose of this paper is to address this gap in knowledge.

Design/methodology/approach

A two-pronged approach was taken. First, a data sample of 554 articles was analyzed and 178 articles found relevant were used to present a systematic, structured framework of risk factors along operational, economic, financial, social and security dimensions. Then informed by the theory of risk management and supplemented by literature evidence, we have built a BRI SC risk model.

Findings

The results presented through the model show that BRI SCs face a combination of risks triggered by operational processes, informational and environmental (PIE) deficiencies. Findings show that lack of risk and liability management, unbalanced risk-sharing partnerships, lack of transparency, inadequate project evaluation, incompatible corporate governance structures and cyber security all pose threats to BRI SCs specifically and SCs in general.

Research limitations/implications

Academically, the results facilitate theory development by identifying and proposing seven risk factors and modeling relationship among them and BRI SC risks outcome. The results also extend application of theory of risk management to SC context.

Practical implications

The findings provide a decision-making tool for managers to assess risk factors in their SCs, thus enabling improved decision making to avoid, mitigate, transfer or accept risks.

Originality/value

Identifies and proposes a set of seven risk factors that drive BRI SC risks. Develops a model of BRI SC risks which help build theory of SC risk management.
Job satisfaction, distributive justice, perceived absence legitimacy and the role of turnover intentions: an exploratory study in Ghana
Authors: Addae Helena M. , Boso Nathaniel
Published: September 2020

Purpose

This paper aims to investigate the relationship between job satisfaction and distributive justice on employee perceptions of absence legitimacy. This paper also examined the moderating effects of turnover intentions on the relevant relationships.

Design/methodology/approach

The authors used convenience sampling to collect data from 298 employees working in private and public sector organizations in the manufacturing and service sectors in Ghana. Drawing on institutional theory, this study investigates the effects of employee perceptions of the legitimacy of absenteeism on their attitudes toward their job and pay. Structural equation modeling was used to test the direct and moderation effects.

Findings

Job satisfaction and perceived distributive justice were found to be significantly related to the absence of legitimacy. Additionally, turnover intentions moderated the relationship between job satisfaction and absence legitimacy; however, unexpectedly, this was associated only marginally with distributive justice.

Research limitations/implications

The main limitation of this study was that it was cross-sectional, but the analysis did not show a common method bias. This study was conducted in a developing country where valid and accurate absence data are non-existent. The hypotheses were supported. When employees felt a sense of inequity and were dissatisfied with their jobs, they were likely to perceive absenteeism as legitimate behavior. These relationships were more pronounced when employees intended to leave their organizations.

Practical implications

From a practical standpoint, as employees are likely to engage in absenteeism as a means to reduce their perceptions of imbalance and because absenteeism is a costly behavior, it would be in the employer’s best interest to mitigate these high costs. It behooves employers to comprehend the factors that lead to the legitimization of absences. Doing so, they would be able to implement attendance management systems and strategies that would delegitimize some of these factors, thus improving attendance and potentially increasing productivity and job satisfaction and reducing turnover intentions.

Originality/value

This study contributes to absenteeism research because, unlike most studies in the area, it examined employee cognitions of the behavior. Such cognitions should provide insights into how employee perceptions of the legitimacy of absences would affect attitudinal variables such as job satisfaction, feelings of equity and turnover intentions. Moreover, even though the study was conducted in Ghana, absence legitimacy can be investigated in different settings at different levels of analysis. This is because it is free from contamination such as, dissimilar absence reporting systems within and across organizations and nations that affect the validity and accuracy of absence data.
Extension of technology continuance theory (TCT) with task technology fit (TTF) in the context of Internet banking user continuance intention
Authors: Rahi Samar , Khan Mubbsher Munawar , Alghizzawi Mahmoud
Published: September 2020

Purpose

The advancement in Internet technology has played a significant role in revolutionizing the Internet banking services. Therefore, little is discussed about factors that motivate technology user to continue the use of Internet banking services. The current study investigates Internet banking user continuance behavior toward the use of Internet banking services with the integration of two-well known information system (IS) theories namely task technology fit (TTF) and technology continuance theory (TCT).

Design/methodology/approach

The research design of this study is based on positivist paradigm and followed quantitative research approach. Data were collected from 360 Internet banking users of commercial banks across Pakistan. The research model was tested with structural equation modeling (SEM).

Findings

The research model had explained 53.9% variance in Internet banking user continuance intention. Next to this, the predictive relevance of the research model was tested with Stone-Geisser's Q² values using blindfolding procedure. Results revealed that the newly developed integrated technology continuance research model has substantial power to predict Internet banking user continuance intention. Moreover, the effect size analysis revealed that factors like satisfaction and user expectation were the most important factors in determining Internet banking user continuance intention.

Practical implications

For practical implications importance performance matrix analysis (IPMA) has used to see the importance and performance of the underpinned factors. Findings indicate that managers and policy makers should focus on user satisfaction, perceived usefulness and expectation confirmation in order to enhance the Internet banking user continuance intention toward the use of Internet banking services. Some of the ways banks can do this is to develop esthetic Internet banking website with charm of novelty, relevant information and smooth flows with less complex redirects.

Originality/value

Unlike prior studies that focus on Internet banking user pre-adoption issues, the current study examines post-adoption issue of Internet banking users and investigates Internet banking user continuance intention. This study is significant as it integrates two-well known theories namely TCT and TTF in Internet banking user continuance intention and augments the IS literature by developing an integrated technology continuance model (TCM).
The effect of sponsorship purpose articulation on fit: moderating role of mission overlap
Authors: Kang Tae-Ahn , Matsuoka Hirotaka
Published: September 2020

Purpose

This study aimed to examine the effects of two sponsorship purpose articulations (commercially oriented vs noncommercially oriented) on attitude toward the sponsor via sponsor–property fit and the moderating effect of the overlapped mission between the sponsor and the property.

Design/methodology/approach

A 2 (purpose articulation type: commercially oriented vs noncommercially oriented) × 2 (mission overlap articulation condition: present vs absent) between-subjects experimental design with a control condition was employed with student sample (n = 171). The moderated mediation model was tested using Hayes' PROCESS macro model 8.

Findings

The commercially oriented purpose articulation did not improve sponsor–property fit as much as the noncommercially oriented purpose articulation, resulting in less favorable attitudes toward the sponsor. When the mission overlap was simultaneously articulated, the less positive effects of the commercially oriented purpose articulation were weaker.

Practical implications

The findings provided incongruent sponsors with insights on mixed articulation strategies with sponsorship purposes and the overlapped mission.

Originality/value

This study extends previous research by presenting the first understanding of the different processes in which two sponsorship purpose articulations developed attitudes toward the sponsor via sponsor–property fit and by investigating the moderating effect of the simultaneously articulated mission overlap on the processes.
Social network analysis of an emerging innovation: direct-to-garment printing technology
Authors: Yu Yanan , Moore Marguerite , Chapman Lisa P.
Published: September 2020

Purpose

The study primarily aims to examine an emerging fashion technology, direct-to-garment (DTG) printing, using data mining-driven social network analysis (SNA). Simultaneously, the study also demonstrates application of a group novel computational technique to capture, analyze and visually depict data for strategic insight into the fashion industry.

Design/methodology/approach

A total of 5,060 tweets related to DTG were captured using Crimson Hexagon. Python and Gephi were applied to convert, calculate and visualize the yearly networks for 2016–2019. Based on graph theory, degree centrality and betweenness centrality indices guide interpretation of the outcome networks.

Findings

The findings reveal insights into DTG printing technology networks through identification of interrelated indicators (i.e. nodes, edges and communities) over time. Deeper interpretation of the dominant indicators and the unique changes within each of the DTG communities were investigated and discussed.

Practical implications

Three SNA models suggest directions including the dominant apparel categories for DTG application, competing alternatives for apparel decorating approaches to DTG and growing market niches for DTG. Interpretation of the yearly networks suggests evolution of this domain over the investigation period.

Originality/value

The social media based, data mining-driven SNA method provides a novel path and a powerful technique for scholars and practitioners to investigate information among complex, abstract or novel topics such as DTG. Context specific findings provide initial insight into the evolving competitive structures driving DTG in the fashion market.