bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrospun polyester-urethane scaffold preserves mechanical properties and exhibits strain stiffening during in situ tissue ingrowth and degradation
Authors: Krynauw Hugo , Omar Rodaina , Koehne Josepha , Limbert Georges , Davies Neil H , Bezuidenhout Deon , Franz Thomas
Published: September 2019

Consistent mechanical performance from implantation through healing and scaffold degradation is highly desired for tissue-regenerative scaffolds, e.g. when used for vascular grafts. The aim of this study was the paired in vivo mechanical assessment of biostable and fast degrading electrospun polyester-urethane scaffolds to isolate the effects of material degradation and tissue formation after implantation. Biostable and degradable polyester-urethane scaffolds with substantial fibre alignment were manufactured by electrospinning. Scaffold samples were implanted paired in subcutaneous position in rats for 7, 14 and 28 days. Morphology, mechanical properties and tissue ingrowth of the scaffolds were assessed before implantation and after retrieval. Tissue ingrowth after 28 days was 83 ± 10% in the biostable scaffold and 77 ± 4% in the degradable scaffold. For the biostable scaffold, the elastic modulus at 12% strain increased significantly between 7 and 14 days and decreased significantly thereafter in fibre but not in cross-fibre direction. The degradable scaffold exhibited a significant increase in the elastic modulus at 12% strain from 7 to 14 days after which it did not decrease but remained at the same magnitude, both in fibre and in cross-fibre direction. Considering that the degradable scaffold loses its material strength predominantly during the first 14 days of hydrolytic degradation (as observed in our previous in vitro study), the consistency of the elastic modulus of the degradable scaffold after 14 days is an indication that the regenerated tissue construct retains it mechanical properties.
Immunization of mice with chimeric antigens displaying selected epitopes confers protection against intestinal colonization and renal damage caused by Shiga toxin-producingEscherichia coli
Authors: Montero David A. , Del Canto Felipe , Salazar Juan C. , Cespedes Sandra , Cádiz Leandro , Arenas-Salinas Mauricio , Reyes José , Oñate Ángel , Vidal Roberto M.
Published: September 2019

Shiga toxin-producingEscherichia coli(STEC) cause diarrhea and dysentery, which may progress to hemolytic uremic syndrome (HUS). Vaccination has been proposed as a preventive approach against STEC infection; however, there is no vaccine for humans and those used in animals reduce but do not eliminate the intestinal colonization of STEC. The OmpT, Cah and Hes proteins are widely distributed among clinical STEC strains and are recognized by serum IgG and IgA in patients with HUS. Here, we develop a vaccine formulation based on two chimeric antigens containing epitopes of OmpT, Cah and Hes proteins against STEC strains. Intramuscular and intranasal immunization of mice with these chimeric antigens elicited systemic and local long-lasting humoral responses. However, the class of antibodies generated was dependent on the adjuvant and the route of administration. Moreover, while intramuscular immunization with the combination of the chimeric antigens conferred protection against colonization by STEC O157:H7 and the intranasal conferred protection against renal damage caused by STEC O91:H21. This pre-clinical study supports the potential use of this formulation based on recombinant chimeric proteins as a preventive strategy against STEC infections.
Cortical anchoring of the microtubule cytoskeleton is essential for neuron polarity and functioning
Authors: He Liu , Kooistra Robbelien , Das Ravi , Oudejans Ellen , van Leen Eric V. , Ziegler Johannes , Portegies Sybren , de Haan Bart , van Regteren Altena Anna S. , Stucchi Riccardo , Altelaar Maarten A. F. , Wieser Stefan , Krieg Michael , Hoogenraad Casper C. , Harterink Martin
Published: September 2019

Neurons are among the most highly polarized cell types. They possess structurally and functionally different processes, axon and dendrites, to mediate information flow through the nervous system. Although it is well known that the microtubule cytoskeleton has a central role in establishing neuronal polarity, how its specific organization is established and maintained is little understood.

Using the in vivo model system Caenorhabditis elegans, we found that the highly conserved UNC-119 protein provides a link between the membrane-associated Ankyrin (UNC-44) and the microtubule-associated CRMP (UNC-33). Together they form a periodic membrane-associated complex that anchors axonal and dendritic microtubule bundles to the cell cortex. This anchoring is critical to maintain microtubule organization by opposing kinesin-1 powered microtubule sliding. Disturbing this molecular complex alters neuronal polarity and causes strong developmental defects of the nervous system leading to severely paralyzed animals.
Neural processing of iterated prisoner’s dilemma outcomes indicates next-round choice and speed to reciprocate cooperation
Authors: Constantino Francisco Cervantes , Garat Santiago , Nicolaisen-Sobesky Eliana , Paz Valentina , Martínez-Montes Eduardo , Kessel Dominique , Cabana Álvaro , Gradin Victoria B
Published: September 2019

Electing whether to cooperate with someone else is well typified in the iterated prisoner’s dilemma (iPD) game, although the neural processes that unfold after its distinct outcomes have been only partly described. Recent theoretical models emphasize the ubiquity of intuitive cooperation, raising questions on the neural timelines involved. We studied the outcome stage of an iPD with electroencephalography (EEG) methods. Results showed that neural signals that are modulated by the iPD outcomes can also be indicative of future choice, in an outcome-dependent manner: (i) after zero-gain ‘sucker’s payoffs’ (unreciprocated cooperation), a participant’s decision thereafter may be indicated by changes to the feedback-related negativity (FRN); (ii) after one-sided non-cooperation (participant gain), by the P3; (iii) after mutual cooperation, by late frontal delta-band modulations. Critically, faster choices to reciprocate cooperation were predicted, on a single-trial basis, by P3 and frontal delta modulations at the immediately preceding trial. Delta band signaling is considered in relation to homeostatic regulation processing in the literature. The findings relate feedback to decisional processes in the iPD, providing a first neural account of the brief timelines implied in heuristic modes of cooperation.
A model of Zebrafish Avatar for co-clinical trials
Authors: Usai Alice , Franco Gregorio Di , Colucci Patrizia , Pollina Luca Emanuele , Vasile Enrico , Funel Niccola , Palmeri Matteo , Dente Luciana , Falcone Alfredo , Morelli Luca , Raffa Vittoria
Published: September 2019

Animal ‘‘Avatars’’ and co-clinical trials represent an emerging concept for implementing schemes of personalized medicine in oncology. In a co-clinical trial, the cancer cells of the patient tumor are xenotransplanted in the animal Avatar for drug efficacy studies and data collected in the animal trial are used to plan the best drug treatment in the patient trial. Recently, zebrafish has been proposed for implementing Avatar models but the lack of a general criterion for chemotherapy dose conversion from humans to fishes represents a limitation for conducting co-clinical trials.

Here, we validate a simple, reliant and cost-effective Avatar model based on the use of zebrafish larvae; by crossing data from safety and efficacy studies, we found a basic formula for the estimation of the dose to be used for running co-clinical trials and we validate it in a clinical study enrolling 24 adult patients with solid cancers (XenoZ, NCT03668418).
Loss of Bacterial Cell Pole Stabilization inCaulobacter crescentusSensitizes to Outer Membrane Stress and Peptidoglycan-Directed Antibiotics
Authors: Vallet Simon-Ulysse , Hansen Lykke Haastrup , Bistrup Freja Cecillie , Chapalay Julien Bortoli , Chambon Marc , Turcatti Gerardo , Viollier Patrick H. , Kirkpatrick Clare L.
Published: September 2019

Rod-shaped bacteria frequently localise proteins to one or both cell poles in order to regulate processes such as chromosome replication or polar organelle development. However, the role of such polar factors in responses to extracellular stimuli has been generally unexplored. We employed chemical-genetic screening to probe the interaction between one such factor fromCaulobacter crescentus, TipN, and extracellular stress and found that TipN is required for normal tolerance of cell envelope-directed antibiotics, including vancomycin that does not normally inhibit growth of Gram-negative bacteria. Forward genetic screening for suppressors of vancomycin sensitivity in the absence of TipN revealed the TonB-dependent receptor ChvT as the mediator of vancomycin tolerance. Loss of ChvT improved resistance to vancomycin and cefixime in the otherwise sensitive ΔtipNstrain. The activity of the two-component system regulating ChvT (ChvIG) was increased in ΔtipNcells relative to wild type under some, but not all, cell wall stress conditions that this strain was sensitised to, in particular cefixime and detergent exposure. Together, these results indicate that the ChvIG two-component system has been co-opted as a sensor of cell wall stress and that TipN can influence cell envelope stability and ChvIG-mediated signaling in addition to its roles in intracellular development.

Author summary

Maintenance of an intact cell envelope is essential for free-living bacteria to survive harsh conditions they may encounter in their environment. In the case of rod-shaped bacteria, the poles of the cell are potential weak points in the cell envelope due to the high curvature of the layers and the need to break and re-form parts of the cell envelope at the division plane in order to form new poles as the cells replicate and divide. We have found that TipN, a factor required for correct division and cell pole development in the rod-shaped bacterium,Caulobacter crescentus, is also needed for maintaining normal levels of resistance to cell wall-targeting antibiotics such as vancomycin and cefixime, which interfere with peptidoglycan synthesis. We also identified an outer membrane receptor, ChvT, that was responsible for allowing vancomycin access to the cells and found that the two-component system that negatively regulates ChvT production was activated by various kinds of cell wall stress. Presence or absence of TipN influenced how active this system was in the presence of cefixime or of the membrane-disrupting detergent sodium deoxycholate. Since TipN is normally located at the poles of the cell and at the division plane just before cells complete division, our results suggest that it is involved in stabilisation of these weak points of the cell envelope as well as its other roles inside the cell.
Spleen Transcriptome Analysis of C57BL/6 Mouse in Response to Hot Water Extract from Spent Mushroom Substrate ofGanoderma lucidumand Cyclophosphamide
Authors: Wang Zehui , Wang Annan , Li Jing , Liao Zhen , Sun Lianyue , Lin Zhanxi , Liu Yanling
Published: September 2019

Previously, we have indicated that Hot Water Extract (HWE) from Spent Mushroom Substrate (SMS) ofGanoderma lucidumenhanced immune function of normal mice, and improved antioxidant activity and enhanced immune function of immunosuppression mice induced by cyclophosphamide (Cy). Here we performed the high throughput RNA sequencing strategy using Illumina HiSeq™ 2000 to characterize the spleen transcriptome from normal (CK1), HWE-treated (CK2), Cy-treated (CY) and both high dose HWE and Cy-treated mice (CH). From the RNA Sequencing, total mapped reads of map to Gene in CK1, CK2, CY and CH was 54 759 942, 54 678 926, 44 728 132 and 54 006 596, respectively. And gene expression was significantly different among CK1 and CK2, CY and CH. Compared with CK1, the gene expression ofUgt1a6bwas down-regulated in CK2 after HWE treated. In addition, compared with CY, multiple tumor suppressor or tumorigenesis genes were down-regulated, such asCdkn1a,Cdkn1b,Mapk10,Vash1, andTncand other genes in CK2 and CH. Taken together, our study highlighted the spleen transcriptome profiles of C57BL/6 mouse in response to HWE from SMS ofG. lucidumand Cy, and indicated that HWE can improve the immune function of the mouse and accelerated the recovery of immunosuppression in Cy-treated mice.
3D Genome Structure Variation Across Cell Types Captured by Integrating Multi-omics
Authors: Xu Yang , Shen Tongye , McCord Rachel Patton
Published: September 2019

Background

3D genome structure contributes to the establishment or maintenance of cell identity in part by organizing genes into spatial active or inactive compartments. Less is known about how compartment switching occurs across different cell types. Rather than analyze individual A/B compartment switches between pairs of cell types, here, we seek to identify coordinated changes in groups of compartment-scale interactions across a spectrum of cell types.

Results

To characterize the impact of genome folding on cell identity, we integrated 35 Hi-C datasets with 125 DNase-seq, 244 RNA-seq, and 893 ChIP-seq datasets. We first find physical associations with the nuclear lamina inform the most dramatic changes in chromosome structure across cell types. By examining variations in chromosome structure, transcription, and chromatin accessibility, we further observe that certain sets of correlated chromosome structure contacts also co-vary in transcription and chromatin accessibility. Analyzing ChIP-seq signals, we find that sets of chromosome contacts that form and break in sync tend to share active or suppressive histone marks. Finally, we observe that similar principles appear to govern chromosome structure fluctuations across single cells as were found across cell types.

Conclusion

Our results suggest that cells adapt their chromosome structures, guided by variable associations with the lamina and histone marks, to allocate up-regulatory or down-regulatory resources to certain regions and achieve transcription and chromatin accessibility variation. Our study shows E-PCA can identify the major variable interaction sets within populations of single cells, across broad categories of normal cell types, and between cancer and non-cancerous cell types.
Structure and mechanism of a Type III CRISPR defence DNA nuclease activated by cyclic oligoadenylate
Authors: McMahon Stephen A , Zhu Wenlong , Graham Shirley , Rambo Robert , White Malcolm F , Gloster Tracey M
Published: September 2019

The CRISPR system provides adaptive immunity against mobile genetic elements in prokaryotes. On binding invading RNA species, Type III CRISPR systems generate cyclic oligoadenylate (cOA) molecules which act as a second messenger, signalling infection and potentiating a powerful immune response by activating a range of downstream effector proteins that can lead to viral clearance, cell dormancy or death. Only one type of effector enzyme has been studied – the Csm6/Csx1 ribonuclease domain, and the mechanism of cOA activation is not understood at a molecular level. Here we describe the structure and mechanism of a novel cOA-activated CRISPR defence DNA endonuclease, Can1 (“CRISPR ancillary nuclease 1”). Can1 has a unique monomeric structure with two CRISPR associated Rossman fold (CARF) CARF domains and two DNA nuclease-like domains. The crystal structure of the enzyme has been captured in the activated state, with a cyclic tetra-adenylate (cA4) molecule bound at the core of the protein. cA4 binding reorganises the structure to license a metal-dependent DNA nuclease activity specific for nicking of supercoiled DNA. DNA nicking by Can1 is predicted to slow down viral replication kinetics by leading to the collapse of DNA replication forks.
A quiescent state following mild sensory arousal inCaenorhabditis elegansis potentiated by stress
Authors: McClanahan Patrick D. , Dubuque Jessica M. , Kontogiorgos-Heintz Daphne , Habermeyer Ben F. , Xu Joyce H. , Ma Anthony M. , Raizen David M. , Fang-Yen Christopher
Published: September 2019

An animal’s behavioral and physiological response to stressors includes changes to its responses to stimuli. How such changes occur is not well understood. Here we describe aCaenorhabditis elegansquiescent behavior, post-response quiescence (PRQ), which is modulated by theC. elegansresponse to cellular stressors. Following an aversive mechanical or blue light stimulus, worms respond first by briefly moving, and then become more quiescent for a period lasting tens of seconds. PRQ occurs at low frequency in unstressed animals, but is more frequent in animals that have experienced cellular stress due to ultraviolet light exposure as well as in animals following overexpression of epidermal growth factor (EGF). PRQ requires the function of the carboxypeptidase EGL-21 and the calcium-activated protein for secretion (CAPS) UNC-31, suggesting it has a neuropeptidergic mechanism. Although PRQ requires the sleep-promoting neurons RIS and ALA, it is not accompanied by decreased arousability, and does not appear to be homeostatically regulated, suggesting that it is not a sleep state. PRQ represents a simple, tractable model for studying how neuromodulatory states like stress alter behavioral responses to stimuli.
Simultaneous and precise generation of Zebra3 and Wsl5 mutations in rice using CRISPR/Cas9-mediated adenine base editors
Authors: Molla Kutubuddin A. , Shih Justin , Yang Yinong
Published: September 2019

The CRISPR/Cas9-mediated base editing technology can efficiently generate point mutations in the genome without introducing double-strand break (DSB) or supplying a DNA donor template for homology-dependent repair (HDR). In this study, adenine base editors (ABEs) were used for rapid generation of precise point mutations in two distinct genes, OsWsl5, and OsZebra3 (Z3), in rice protoplasts and regenerated plants. The precisely engineered point mutations were stably inherited to subsequent generations. These single nucleotide alterations resulted in single amino acid changes and associated wsl5 and z3 phenotypes as evidenced by white stripe leaf and light green/dark green leaf pattern, respectively. Through selfing and segregation, transgene-free, base edited wsl5 and z3 mutants were readily obtained in a short period of time. We noticed a novel mutation (V540A) in Z3 locus could mimic the phenotype of Z3 mutation (S542P). Furthermore, we observed unexpected non-A/G or T/C mutations in the ABE editing window in a few of the edited plants. The ABE vectors and the method from in this study could be used to simultaneously generate point mutations in multiple genes in a single transformation and serve as a useful base editing tool for crop improvement as well as basic studies in plant biology.

Highlights

Adenine base editors were adapted for plant base editing that can generate precise and heritable point mutations in rice genome without indel formation. The base editing approach allows rapid generation of transgene-free rice mutants with expected phenotypic changes.
Genotyping-by-sequencing illuminates high levels of divergence among sympatric forms of coregonines in the Laurentian Great Lakes
Authors: Ackiss Amanda S. , Larson Wesley A. , Stott Wendylee
Published: September 2019

Effective resource management depends on our ability to partition diversity into biologically meaningful units. Recent evolutionary divergence, however, can often lead to ambiguity in morphological and genetic differentiation, complicating the delineation of valid conservation units. Such is the case with the “coregonine problem,” where recent post-glacial radiations of coregonines into lacustrine habitats resulted in the evolution of numerous species flocks, often with ambiguous taxonomy. The application of genomics methods is beginning to shed light on this problem and the evolutionary mechanisms underlying divergence in these ecologically and economically important fishes. Here, we used restriction site-associated DNA (RAD) sequencing to examine genetic diversity and differentiation among sympatric species in theCoregonus artedicomplex in the Apostle Islands of Lake Superior, the largest lake in the Laurentian Great Lakes. Using 29,068 SNPs, we were not only able to clearly distinguish the three most common forms for the first time, but putative hybrids and potentially mis-identified specimens as well. Assignment rates to form with our RAD data were 93-100% with the only mis-assignments arising from putative F1 hybrids, an improvement from 62-77% using microsatellites. Estimates of pairwise differentiation (FST: 0.045-0.056) were large given the detection of hybrids, suggesting that hybridization among forms may not be successful beyond the F1 state. We also used a newly builtC. artedilinkage map to look for islands of adaptive genetic divergence among forms and found widespread differentiation across the genome, a pattern indicative of long-term drift, suggesting that these forms have been reproductively isolated for a substantial amount of time. The results of this study provide valuable information that can be applied to develop well-informed management strategies and stress the importance of re-evaluating conservation units with genomic tools to ensure they accurately reflect species diversity.
Harmonization of large multi-site imaging datasets: Application to 10,232 MRIs for the analysis of imaging patterns of structural brain change throughout the lifespan
Authors: Pomponio Raymond , Erus Guray , Habes Mohamad , Doshi Jimit , Srinivasan Dhivya , Mamourian Elizabeth , Bashyam Vishnu , Fan Yong , Launer Lenore J. , Masters Colin L. , Maruff Paul , Zhuo Chuanjun , Nasrallah Ilya M. , Völzke Henry , Johnson Sterling C. , Fripp Jurgen , Koutsouleris Nikolaos , Satterthwaite Theodore D. , Wolf Daniel H. , Gur Raquel , Gur Ruben , Morris John , Albert Marilyn S. , Grabe Hans J. , Resnick Susan M. , Bryan R. Nick , Wolk David A. , Shinohara Russell T. , Shou Haochang , Davatzikos Christos
Published: September 2019

As medical imaging enters its information era and presents rapidly increasing needs for big data analytics, robust pooling and harmonization of imaging data across diverse cohorts with varying acquisition protocols have become critical. We describe a comprehensive effort that merges and harmonizes a large-scale dataset of 10,232 structural brain MRI scans from participants without known neuropsychiatric disorder from 18 different studies that represent geographic diversity. We use this dataset and multi-atlas-based image processing methods to obtain a hierarchical partition of the brain from larger anatomical regions to individual cortical and deep structures and derive normative age trends of brain structure through the lifespan (3 to 96 years old). Critically, we present and validate a methodology for harmonizing this pooled dataset in the presence of nonlinear age trends. We provide a web-based visualization interface to generate and present the resulting age trends, enabling future studies of brain structure to compare their data with this normative reference of brain development and aging, and to examine deviations from normative ranges, potentially related to disease.
Cytosolic Ca2+modulates Golgi structure through PKC-mediated GRASP55 phosphorylation
Authors: Ireland Stephen C. , Ramnarayanan Saiprasad , Fu Mingzhou , Zhang Xiaoyan , Emebo Dabel , Wang Yanzhuang
Published: September 2019

It has been well documented that the endoplasmic reticulum (ER) responds to cellular stresses through the unfolded protein response (UPR), but it is unknown how the Golgi responds to similar stresses. In this study, we treated HeLa cells with ER stress inducers, thapsigargin (TG), tunicamycin (Tu) and Dithiothreitol (DTT), and found that only TG treatment caused Golgi fragmentation. TG induced Golgi fragmentation at a low dose and short time when UPR was undetectable, demonstrating that Golgi fragmentation occurs independently of ER stress. Further experiments demonstrated that TG induces Golgi fragmentation through elevated intracellular Ca2+and protein kinase Cα (PKCα) activity, which phosphorylates the Golgi stacking protein GRASP55. Significantly, activation of PKCα with other activating or inflammatory agents, including Phorbol 12-myristate 13-acetate (PMA) and histamine, modulates the Golgi structure in a similar fashion. Hence, our study revealed a novel mechanism through which increased cytosolic Ca2+modulates Golgi structure and function.
Quantitative Genomic Dissection of Soybean Yield Components
Authors: Xavier Alencar , Rainey Katy M
Published: September 2019

Soybean is a crop of major economic importance with low rates of genetic gains for grain yield compared to other field crops. A deeper understanding of the genetic architecture of yield components may enable better ways to tackle the breeding challenges. Key yield components include the total number of pods, nodes and the ratio pods per node. We evaluated the SoyNAM population, containing approximately 5600 lines from 40 biparental families that share a common parent, in 6 environments distributed across 3 years. The study indicates that the yield components under evaluation have low heritability, a reasonable amount of epistatic control, and partially oligogenic architecture: 18 quantitative trait loci were identified across the three yield components using multi-approach signal detection. Genetic correlation between yield and yield components was highly variable from family-to-family, ranging from −0.2 to 0.5. The genotype-by-environment correlation of yield components ranged from −0.1 to 0.4 within families. The number of pods can be utilized for indirect selection of yield. The selection of soybean for enhanced yield components can be successfully performed via genomic prediction, but the challenging data collections necessary to recalibrate models over time makes the introgression of QTLs a potentially more feasible breeding strategy. The genomic prediction of yield components was relatively accurate across families, but less accurate predictions were obtained from within-family predictions and predicting families not observed included in the calibration set.
Two precatalysts for application in propargylic CH activation
Authors: Möller Saskia , Drexler Hans-Joachim , Heller Detlef
Published: September 2019

The complexes {bis[(2-diphenylphosphanyl)phenyl] ether-κ2
P,P′}(η4-norbornadiene)rhodium(I) tetrafluoridoborate, [Rh(C7H8)(C36H28OP2)]BF4, and {bis[(2-diphenylphosphanyl)phenyl] ether-κ2
P,P′}[η4-(Z,Z)-cycloocta-1,5-diene]rhodium(I) tetrafluoridoborate dichloromethane monosolvate, [Rh(C8H12)(C36H28OP2)]BF4·CH2Cl2, are applied as precatalysts in redox-neutral atomic-economic propargylic CH activation [Lumbroso et al. (2013). Angew. Chem. Int. Ed.
52, 1890–1932]. In addition, the catalytically inactive pentacoordinated 18-electron complex {bis[(2-diphenylphosphanyl)phenyl] ether-κ2
P,P′}chlorido(η4-norbornadiene)rhodium(I), [RhCl(C7H8)(C36H28OP2)], was synthesized, which can form in the presence of chloride in the reaction system.
How the oxazole fragment influences the conformation of the tetraoxazocane ring in a cyclohexanespiro-3′-(1,2,4,5,7-tetraoxazocane): single-crystal X-ray and theoretical study
Authors: Khalilov Leonard M. , Mescheryakova Ekaterina S. , Bikmukhametov Kamil Sh. , Makhmudiyarova Nataliya N. , Shangaraev Kamil R. , Tulyabaev Arthur R.
Published: September 2019

Single crystals of (2S,5R)-2-isopropyl-5-methyl-7-(5-methylisoxazol-3-yl)cyclohexanespiro-3′-(1,2,4,5,7-tetraoxazocane), C16H26N2O5, have been studiedviaX-ray diffraction. The tetraoxazocane ring adopts a boat–chair conformation in the crystalline state, which is due to intramolecular interactions. Conformational analysis of the tetraoxazocane fragment performed at the B3LYP/6-31G(d,2p) level of theory showed that there are three minima on the potential energy surface, one of which corresponds to the conformation realized in the solid state, but not to a global minimum. Analysis of the geometry and the topological parameters of the electron density at the (3,−1) bond critical points (BCPs), and the charge transfer in the tetraoxazocane ring indicated that there are stereoelectronic effects in the O—C—O and N—C—O fragments. There is a two-cross hyperconjugation in the N—C—O fragment between the lone electron pair of the N atom (lpN) and the antibonding orbital of a C—O bond (σ*C—O) andvice versabetween lpO and σ*C—N. The oxazole substituent has a considerable effect on the geometry and the topological parameters of the electron density at the (3,−1) BCPs of the tetraoxazocane ring. The crystal structure is stabilizedviaintermolecular C—H...N and C—H...O hydrogen bonds, which is unambiguously confirmed with PIXEL calculations, a quantum theory of atoms in molecules (QTAIM) topological analysis of the electron density at the (3,−1) BCPs and a Hirshfeld analysis of the electrostatic potential. The molecules form zigzag chains in the crystal due to intermolecular C—H...N interactions being electrostatic in origin. The molecules are further stacked due to C—H...O hydrogen bonds. The dispersion component in the total stabilization energy of the crystal lattice is 68.09%.
Crystal structure and Hirshfeld surface analysis of N-(tert-butyl)-2-(phenylethynyl)imidazo[1,2-a]pyridin-3-amine
Authors: Tber Zahira , Kansiz Sevgi , El Hafi Mohamed , Loubidi Mohamed , Jouha Jabrane , Dege Necmi , Essassi El Mokhtar , Mague Joel T.
Published: September 2019

The bicyclic imidazo[1,2-a]pyridine core of the title compound, C19H19N3, is relatively planar with an r.m.s. deviation of 0.040 Å. The phenyl ring is inclined to the mean plane of the imidazo[1,2-a]pyridine unit by 18.2 (1)°. In the crystal, molecules are linked by N—H...H hydrogen bonds, forming chains along the c-axis direction. The chains are linked by C—H...π interactions, forming slabs parallel to the ac plane. The Hirshfeld surface analysis and fingerprint plots reveal that the crystal structure is dominated by H...H (54%) and C...H/H...C (35.6%) contacts. The crystal studied was refined as an inversion twin
In situ decarbonylation of N,N-dimethylformamide to form dimethylammonium cations in the hybrid framework compound {[(CH3)2NH2]2[Zn{O3PC6H2(OH)2PO3}]}
n
Authors: Soriano Josemaria S. , Galeas Bryan E. , Garrett Paul , Flores Ryan A. , Pinedo Juan L. , Kohlgruber Tsuyoshi A. , Felton Daniel , Adelani Pius O.
Published: September 2019

The title phosphonate-based organic–inorganic hybrid framework, poly[bis(dimethylammonium) [(μ4-2,5-dihydroxybenzene-1,4-diphosphonato)zinc(II)]], {(C2H8N)2[Zn(C6H4O8P2)]}
n
, was formed unexpectedly when dimethylammonium cations were formed from the in situ decarbonylation of the N,N-dimethylformamide solvent. The framework is built up from ZnO4 tetrahedra and bridging diphosphonate tetra-anions to generate a three-dimensional network comprising [100] channels occupied by the (CH3)2NH2
+ cations. Within the channels, an array of N—H...O hydrogen bonds help to establish the structure. In addition, intramolecular O—H...O hydrogen bonds between the appended –OH groups of the phenyl ring and adjacent PO3
2− groups are observed.
Crystal structures of two 4H-chromene derivatives: 2-amino-3-cyano-4-(3,4-dichlorophenyl)-7-hydroxy-4H-benzo[1,2-b]pyran 1,4-dioxane monosolvate and 2-amino-3-cyano-4-(2,6-dichlorophenyl)-7-hydroxy-4H-benzo[1,2-b]pyran
Authors: Silambarasan S. , Nasser A. Jamal Abdul , Mohandas T.
Published: September 2019

In the title compounds, C16H9Cl2N2O2·C4H8O2 and C16H9Cl2N2O2, the bicyclic 4H-chromene cores are nearly planar with maximum deviations of 0.081 (2) and 0.087 (2) Å. In both structures, the chromene derivative molecules are linked into centrosymmetric dimers by pairs of N—H...O hydrogen bonds, forming R2
2
(16) motifs. These dimers are further linked in the 3,4-dichlorophenyl derivative by N—H...N hydrogen bonds into double layers parallel to (100) and in the 2,6-dichlorophenyl derivative by O—H...N hydrogen bonds into ribbons along the [1\overline{1}0] direction. In the 3,4-dichlorophenyl derivative, the 1,4-dioxane solvent molecules are connected to the chromene molecules via O—H...O hydrogen bonds.
The motives for Japanese foreign direct investment in the Southeastern United States
Authors: Magnier-Watanabe Remy , Hoadley James
Published: September 2019

Purpose

Whereas the USA is still the largest investment destination for Japanese companies, Japan also accounts as the second largest source of investment in the country. The purpose of this paper is to, empirically, examine the detailed motives of Japanese affiliates when investing in the Southeastern USA, adding to previous research at the national level.

Design/methodology/approach

This paper uses a qualitative approach based on the interviews of long-term Japanese investors in the manufacturing and wholesale trade industries in the Southeastern USA and applies text analysis to identify their motives.

Findings

The results show that Japanese firms engage in market- and efficiency-seeking foreign direct investment (FDI), and still apply a classic sequence of gradual and incremental market commitments. Market size and growth rate, reducing transaction or transportation costs, and integration within local value chains are the most important to them, whereas competition, creating an export base, lowering tax and accessing skilled labor are of little concern.

Practical implications

The goal of Japanese FDI in the USA is no longer to bypass tariffs but is still part of a complex industrial network of relations which drives further investment. This result can inform policy makers at the state level about the factors that can drive additional foreign investment, such as the establishment of industrial clusters.

Originality/value

This study offers current insights into the motives of Japanese FDI in two industries.
Corporate voluntary carbon disclosure strategy and carbon performance in the USA
Authors: Datt Ragini Rina , Luo Le , Tang Qingliang
Published: September 2019

Purpose

This study aims to examine whether good carbon performers disclose more carbon information overall than poor performers, and if yes, how firms select different types of carbon information to signal their genuine superior carbon performance.

Design/methodology/approach

The level of disclosure is measured based on content analysis of Carbon Disclosure Project (CDP) reports. The study sample consists of 487 US companies that voluntarily participated in the CDP survey from 2011 to 2012. The authors use thet-test and multiple regression models for analyses.

Findings

The results consistently indicate that firms with better carbon performance disclose a greater amount of overall carbon information, supporting the signalling theory. In addition, in contrast to previous studies that merely consider the overall disclosure level, the authors also investigate disclosure of each major aspect of carbon activities. The results show that good carbon performers disclose more key carbon items, such as goods and services that avoid greenhouse gas (GHG) emissions, external verification and carbon accounting, to signal their true type.

Research limitations/implications

This study has some limitations. The authors rely on CDP reports for analysis and focus on the largest companies in the USA. Caution should be exercised when generalising the results to other countries, smaller firms or voluntary carbon information disclosed in other communications channels.

Practical implications

Because carbon disclosure has already been moving from a voluntary to mandatory requirement in many jurisdictions, the format and content of CDP reports might be considered for a formal standalone GHG statement. Based on the results, the authors believe that there should be industry-specific disclosure guidelines, and more disclosure should be made at the project level.

Originality/value

In the context of climate change, this study provides support for the signalling theory by utilising the relationship between voluntary carbon disclosure and performance. The study also provides empirical evidence on how companies may use different types of carbon information to signal their underlying carbon performance.
Corporate governance, board ethnicity and financial statement fraud: evidence from Malaysia
Authors: Nasir Noorul Azwin Binti Md , Ali Muhammad Jahangir , Ahmed Kamran
Published: September 2019

Purpose

This study aims to examine the relationship between the presence of a Malay director on the board and financial statement fraud in Malaysia. Further, the authors investigate whether financial statement fraud firms improve their governance mechanisms compared to non-fraud firms subsequent to the fraud year.

Design/methodology/approach

The authors use hand-collected data comprising 76 financial statement fraud and 76 non-fraud firms over a period of eight years from 2001 to 2008.

Findings

Using a univariate and logistic regression model, the results demonstrate a significant positive relationship between the proportion of Malay directors on the board and the financial statement fraud. The authors also find that fraud firms significantly increase the proportion of independent directors on their boards, increase the frequency of board and audit committee meetings and reduce duality subsequent to the detection of financial statement fraud compared to the non-fraud firms.

Originality/value

The findings of the study are useful to policy-makers, regulators, firms and investors.
Board gender composition, dividend policy and COD: the implications of CEO duality
Authors: Benjamin Samuel Jebaraj , Biswas Pallab
Published: September 2019

Purpose

This study aims to examine whether CEO duality affects the association between board gender composition, dividend policy and cost of debt (COD).

Design/methodology/approach

The S&P 1500 firms’ data for this study were collected from the Bloomberg professional service terminal for the period 2010-2015.

Findings

The results show that board gender composition positively impacts both a firm’s propensity to pay dividends and the level of payouts. However, this positive association is only present in firms with CEO duality. The authors find no significant association between board gender composition and COD, but when the authors split the sample into firms with and without CEO duality, the authors find a negative association in firms without CEO duality.

Practical implications

The empirical results highlight important issues for policymakers, managers and investors. The study provides positive feedback on corporate governance rejuvenation efforts that seek to engender and advocate the appointments of female directors to corporate boards. Market participants, such as financial analysts and lenders, could recognize the empirical specifics related to the influence of board gender composition on firms’ dividend policy and COD in the context of CEO duality.

Originality/value

This study fills an important gap in the literature on the relationship between board gender composition and its relation with dividend policy and COD.
Bandits and bounties: the intersection of information search and investment decisions
Authors: Meder Anthony A. , Schwartz Steven , Young Richard
Published: September 2019

Purpose

This paper aims to describe two scenarios where the problem of information search interacts with the firm’s investment decisions. Investment decisions cannot be made separately from the need to acquire information.

Design/methodology/approach

The scenarios are illustrated with easy-to-follow numerical examples. Vignettes put the numerical examples in their real-world context.

Findings

In both scenarios, the firm should choose what might myopically appear as the lower net per value (NPV) alternative to efficiently deal with the information search problem.

Originality/value

Long-term investments are an important topic in the study of both accounting and finance, but it is in the study of accounting where information issues related to long term investments come to the fore. The traditional textbook approach on whether to accept long-term investment opportunities is to use the NPV rule. However, as illustrated in this note, in many important situations where information search is crucial to investment choice, the NPV rule will not lead to efficient investment decisions.
A method for fault diagnosis of nonlinear circuits
Authors: Tadeusiewicz Michal , Halgas Stanislaw
Published: September 2019

Purpose

The purpose of this paper is to develop a method for multiple soft fault diagnosis of nonlinear circuits including fault detection, identification of faulty elements and estimation of their values in real circumstances.

Design/methodology/approach

The method for fault diagnosis proposed here uses a measurement test leading to a system of nonlinear equations expressing the measured quantities in terms of the circuit parameters. Nonlinear functions, which appear in these equations are not given in explicit analytical form. The equations are solved using a homotopy concept. A key problem of the solvability of the equations is considered locally while tracing the solution path. Actual faults are selected on the basis of the observation that the probability of faults in fewer number of elements is greater than in a larger number of elements.

Findings

The results indicate that the method is an effective tool for testing nonlinear circuits including bipolar junction transistors and junction field effect transistors.

Originality/value

The homotopy method is generalized and associated with a restart procedure and a numerical algorithm for solving differential equations. Testable sets of elements are found using the singular value decomposition. The procedure for selecting faulty elements, based on the minimal fault number rule, is developed. The method comprises both theoretical and practical aspects of fault diagnosis.
Outsourcing mandated corporate social responsibility in India: risks and performance
Authors: Subramaniam Nava , Kansal Monika , Mihret Dessalegn Getie , Babu Shekar
Published: September 2019

Purpose

This paper aims to assess the risks and challenges of corporate social responsibility (CSR) management in the Indian-mandated CSR ecosystem from a service purchaser–supplier dualistic perspective and the role management control systems (MCS) and social capital play in managing such risks and challenges.

Design/methodology/approach

This study undertook a qualitative approach that involved in-depth interviews of 22 CSR directors, managers or chief executive officers from 13 central public sector enterprises (CPSEs) that had purchased CSR services and nine managers of non-government organisations (NGOs) serving as CSR suppliers. Data analysis was founded on the principal–agent and social capital theoretical perspectives.

Findings

A highly bureaucratic, time-pressured mandated environment poses several goal congruence and adverse selection threats to outsourced CSR project arrangements. A mix of formal and informal control mechanisms is critical for enhancing trust or bonding between service purchasers and service providers and enriching bridging capital or access to resources derived from interpersonal connections between NGOs and communities.

Practical implications

NGOs and CPSEs may benefit from understanding each other’s goals and culture and using appropriate formal and informal MCS for managing CSR expectations and outcomes.

Originality/value

Drawing on a unique mandatory CSR regime, this study offers principal–agent and social capital perspectives on CSR programme delivery, highlighting the importance of various formal and informal MCS in lowering agency costs in outsourced CSR relationships.
An ethnographic study comparing approaches to inter-professional knowledge sharing and learning in discharge planning and care transitions
Authors: Waring Justin , Bishop Simon , Marshall Fiona , Tyler Natasha , Vickers Robert
Published: September 2019

Purpose

The purpose of this paper is to investigate how three communication interventions commonly used during discharge planning and care transitions enable inter-professional knowledge sharing and learning as a foundation for more integrated working. These interventions include information communication systems, dedicated discharge planning roles and group-based planning activities.

Design/methodology/approach

A two-year ethnographic study was carried out across two regional health and care systems in the English National Health Service, focussing on the discharge of stroke and hip fracture patients. Data collection involved in-depth observations and 213 semi-structured interviews.

Findings

Information systems (e.g. e-records) represent a relatively stable conduit for routine and standardised forms of syntactic information exchange that can “bridge” time–space knowledge boundaries. Specialist discharge roles (e.g. discharge coordinators) support personalised and dynamic forms of “semantic” knowledge sharing that can “broker” epistemic and cultural boundaries. Group-based activities (e.g. team meetings) provide a basis for more direct “pragmatic” knowledge translation that can support inter-professional “bonding” at the cultural and organisational level, but where inclusion factors complicate exchange.

Research limitations/implications

The study offers analysis of how professional boundaries complicate discharge planning and care transition, and the potential for different communication interventions to support knowledge sharing and learning.

Originality/value

The paper builds upon existing research on inter-professional collaboration and patient safety by focussing on the problems of communication and coordination in the context of discharge planning and care transitions. It suggests that care systems should look to develop multiple complementary approaches to inter-professional communication that offer opportunities for dynamic knowledge sharing and learning.