bluuebunny/crossref_metadata_2025 huggingface dataset:
Pseudomonas aeruginosaincreases the sensitivity of biofilm-grownStaphylococcus aureusto membrane-targeting antiseptics and antibiotics
Authors: Orazi Giulia , Ruoff Kathryn L. , O’Toole George A.
Published: June 2019

Pseudomonas aeruginosaandStaphylococcus aureusoften cause chronic, recalcitrant infections in large part due to their ability to form biofilms. The biofilm mode of growth enables these organisms to withstand antibacterial insults that would effectively eliminate their planktonic counterparts. We found thatP. aeruginosasupernatant increased the sensitivity ofS. aureusbiofilms to multiple antimicrobial compounds, including fluoroquinolones and membrane-targeting antibacterial agents, including the antiseptic chloroxylenol. Treatment ofS. aureuswith the antiseptic chloroxylenol alone did not decrease biofilm cell viability; however, the combination of chloroxylenol andP. aeruginosasupernatant led to a 4-log reduction inS. aureusbiofilm viability compared to exposure to chloroxylenol alone. We found that theP. aeruginosa-produced small molecule 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) is responsible for the observed heightened sensitivity ofS. aureusto chloroxylenol. Similarly, HQNO increased the susceptibility ofS. aureusbiofilms to other compounds, including both traditional and non-traditional antibiotics, which permeabilize bacterial membranes. Genetic and phenotypic studies support a model whereby HQNO causes an increase inS. aureusmembrane fluidity, thereby improving the efficacy of membrane-targeting antiseptics and antibiotics. Importantly, our data show thatP. aeruginosaexoproducts can enhance the ability of various antimicrobial agents to kill biofilm populations ofS. aureusthat are typically difficult to eradicate, providing a path for the discovery of new biofilm-targeting antimicrobial strategies.

Importance

The thick mucus in the airways of cystic fibrosis (CF) patients predisposes them to frequent, polymicrobial respiratory infections.Pseudomonas aeruginosaandStaphylococcus aureusare frequently co-isolated from the airways of individuals with CF, as well as from diabetic foot ulcers and other wounds. Both organisms form biofilms, which are notoriously difficult to eradicate and promote chronic infection. In this study, we have shownP. aeruginosasecreted factors can increase the efficacy of compounds that alone have little or no bactericidal activity againstS. aureusbiofilms. In particular, we discovered thatP. aeruginosaexoproducts can potentiate the anti-staphylococcal activity of phenol-based antiseptics and other membrane-active drugs, including non-traditional antibiotics. Our findings illustrate that polymicrobial interactions can dramatically increase antibacterial efficacyin vitro, and may guide new approaches to target persistent infections, such as those commonly found in respiratory tract infections and in chronic wounds.
Robust summarization and inference in proteome-wide label-free quantification
Authors: Sticker Adriaan , Goeminne Ludger , Martens Lennart , Clement Lieven
Published: June 2019

Label-Free Quantitative mass spectrometry based workflows for differential expression (DE) analysis of proteins impose important challenges on the data analysis due to peptide-specific effects and context dependent missingness of peptide intensities. Peptide-based workflows, like MSqRob, test for DE directly from peptide intensities and outper-form summarization methods which first aggregate MS1 peptide intensities to protein intensities before DE analysis. However, these methods are computationally expensive, often hard to understand for the non-specialised end-user, and do not provide protein summaries, which are important for visualisation or downstream processing. In this work, we therefore evaluate state-of-the-art summarization strategies using a benchmark spike-in dataset and discuss why and when these fail compared to the state-of-the-art peptide based model, MSqRob. Based on this evaluation, we propose a novel summarization strategy, MSqRob-Sum, which estimates MSqRob’s model parameters in a two-stage procedure circumventing the drawbacks of peptide-based workflows. MSqRobSum maintains MSqRob’s superior performance, while providing useful protein expression summaries for plotting and downstream analysis. Summarising peptide to protein intensities considerably reduces the computational complexity, the memory footprint and the model complexity, and makes it easier to disseminate DE inferred on protein summaries. Moreover, MSqRobSum provides a highly modular analysis framework, which provides researchers with full flexibility to develop data analysis workflows tailored towards their specific applications.
Monosynaptic tracing maps brain-wide afferent oligodendrocyte precursor cell connectivity
Authors: Mount Christopher W , Yalçın Belgin , Cunliffe-Koehler Kennedy , Monje Michelle
Published: June 2019

Neurons form bona fide synapses with oligodendrocyte precursor cells (OPCs), but the circuit context of these neuron to OPC synapses remains incompletely understood. Using monosynaptically-restricted rabies virus tracing of OPC afferents, we identified extensive afferent synaptic inputs to OPCs residing in secondary motor cortex, corpus callosum, and primary somatosensory cortex of adult mice. These inputs primarily arise from functionally-interconnecting cortical areas and thalamic nuclei, demonstrating that OPCs have strikingly comprehensive synaptic access to brain-wide functionally-related projection networks. Quantification of these inputs revealed excitatory and inhibitory components that are consistent in number across brain regions and stable in barrel cortex despite whisker trimming-induced sensory deprivation.
One year prevalence of psychotic disorders among first treatment contact patients at Butabika National Psychiatric Referral Hospital in Uganda
Authors: Mwesiga Emmanuel Kiiza , Nakasujja Noeline , Nakku Juliet , Nanyonga Annet , Gumikiriza Joy Louise , Bangirana Paul , Akena Dickens , Musisi Seggane
Published: June 2019

Introduction

Hospital based studies for psychotic disorders are scarce in low and middle income countries. This may impact on development of intervention programs.

Objective

We aimed to determine the burden of psychotic disorders among first treatment contact patients at the national psychiatric referral hospital in Uganda.

Methods

A retrospective patient chart-file review was carried out in March 2019 for all patients presenting to the hospital for the first time in the previous year. Patients were categorised into those with and without psychotic disorders. We collected sociodemographic data on age, gender, occupation, level of education, ethnicity, religion and home district. We determined the one year prevalence of psychotic disorders among first treatment contact patients. Using logistic regression models, we also determined the association between psychotic disorders and various exposure variables among first treatment contact patients.

Results

In 2018, 63% (95% CI: 60.2 – 65.1) of all first time contact patients had a psychosis related diagnosis. Among the patients with psychotic disorders, the median age was 29 years (IQR 24 – 36). Most of the patients were male (62.8%) and unemployed (63.1%). After adjusting for patients’ residence, psychotic disorders were found to be more prevalent among the female gender [OR 1.58 (CI1.46-1.72)] and those of Pentecostal faith [OR 1.25 (CI 1.10-1.42)].

Conclusion

Among first treatment contact patients in Uganda, there is a large burden of psychotic disorders. The burden was more prevalent among females as well as people of Pentecostal faith who seemed to use their church for faith-based healing. Incidence studies are warranted to determine if this phenomenon is replicated at illness onset.
Transcriptome analysis of Xanthomonas oryzae pv. oryzicola exposed to H2O2 reveals horizontal gene transfer contributes to its oxidative stress response
Authors: Fang Yuan , Wang Haoye , Liu Xia , Rao Yuchun , Dedong Xin , Zhu Bo
Published: June 2019

Xanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of bacterial leaf streak in rice. It is known as one of the most severe seed-born bacterial diseases of rice, molecular role governing its interaction with rice is mostly still unexplored. To successfully invade rice, the survival of the Xoc is mandotarory following generating a specific response to its host’s oxidative stress condition. However, the response network of Xoc is still unknown. To address this question, we performed a time-series RNA-seq analysis on the Xoc response to H2O2. Overall, our RNA sequence analysis of Xoc revealed a significant global gene expression profile when it exposed to H2O2. The response of key genes was also noted that soxR triggers and regulates the Xoc oxidative stress response in the early stage of infection, gene expression kinetics among the time-series samples, namely for TonB-dependent receptors and the suf and pst operons. Moreover, a hypothetical protein (XOC_2868) showed significant differential expression following its mutant endorsed RNA-seq findings by clearly displaying a greater H2O2 sensitivity and decreased pathogenicity than the wild-type. Gene location and phylogeny analysis strongly suggests that this gene may have been horizontally transferred from a Burkholderiaceae ancestor. Our study not only provides a first glance of Xoc’s global response against oxidative stress, but it also reveals the impact of horizontal gene transfer in the evolutionary history of Xoc.
Disentangling group specific QTL allele effects from genetic background epistasis using admixed individuals in GWAS: an application to maize flowering
Authors: Simon Rio , Tristan Mary-Huard , Laurence Moreau , Cyril Bauland , Carine Palaffre , Delphine Madur , Valérie Combes , Alain Charcosset
Published: June 2019

When handling a structured population in association mapping, group-specific allele effects may be observed at quantitative trait loci (QTLs) for several reasons: (i) a different linkage disequilibrium (LD) between SNPs and QTLs across groups, (ii) group-specific genetic mutations in QTL regions, and/or (iii) epistatic interactions between QTLs and other loci that have differentiated allele frequencies between groups. We present here a new genome-wide association (GWAS) approach to identify QTLs exhibiting such group-specific allele effects. We developed genetic materials including admixed progeny from different genetic groups with known genome-wide ancestries (local admixture). A dedicated statistical methodology was developed to analyze pure and admixed individuals jointly, allowing one to disentangle the factors causing the heterogeneity of allele effects across groups. This approach was applied to maize by developing an inbred “Flint-Dent” panel including admixed individuals that was evaluated for flowering time. Several associations were detected revealing a wide range of configurations of allele effects, both at known flowering QTLs (Vgt1, Vgt2 and Vgt3) and new loci. We found several QTLs whose effect depended on the group ancestry of alleles while others interacted with the genetic background. The existence of directional epistasis was highlighted by comparing admixed with pure individuals and was consistent with epistatic interactions identified at the level of QTLs. Our GWAS approach provides useful information on the stability of QTL effects across genetic groups and can be applied to a wide range of species.

Author summary

Identification of genomic regions involved in genetic architecture of traits has become commonplace in quantitative genetics studies. Genetic structure is a common feature in human, animal and plant species and most current methods target genomic regions whose effects on traits are conserved between genetic groups. However, a heterogeneity of allele effects may be observed due to different factors: a group-specific correlation between the alleles of the tagged marker and those of the causal variant, a group-specific mutation at the causal variant or an epistatic interaction between the causal variant and the genetic background. We propose a new method adapted to structured populations including admixed individuals, which aims to identify these genomic regions and to unravel the previous factors. method was applied to a maize inbred diversity panel including lines from the dent and the flint genetic groups, as well as admixed lines, evaluated for flowering time. Several genomic regions were detected with various configurations of allele effects, with evidence of epistatic interactions between some of the loci and the genetic background.
On the use of inhibitors of 4-hydroxyphenylpyruvate dioxygenase as a vector-selective insecticide in the control of mosquitoes
Authors: Ramirez Marlon A. V. , Sterkel Marcos , de Jesus Martins Ademir , Lima José Bento Pereira , Oliveira Pedro L.
Published: June 2019

Blood-sucking insects incorporate many times their body weight of blood in a single meal. As proteins are the major component of vertebrate blood, its digestion in the gut of hematophagous insects generates extremely high concentrations of free amino acids. Previous reports showed that the tyrosine degradation pathway plays an essential role in adapting these animals to blood feeding. Inhibiting 4-hydroxyphenylpyruvate dioxygenase (HPPD), the rate-limiting step of tyrosine degradation, results in the death of insects after a blood meal. Therefore, it was suggested that compounds that block the catabolism of tyrosine could act selectively on blood-feeding insects. Here we have evaluated the toxicity against mosquitoes of three HPPD inhibitors currently used as herbicides and in human health. Among the compounds tested, nitisinone (NTBC) proved to be more potent than mesotrione (MES) and isoxaflutole (IFT) in Aedes aegypti. NTBC was lethal to Ae. aegypti in artificial feeding assays (LD50: 4.36 µM), as well as in topical application (LD50: 0.0033 nmol/mosquito). NTBC was also lethal to Ae. aegypti populations that were resistant to neurotoxic insecticides, and it was lethal to other mosquito species (Anopheles and Culex). Therefore, HPPD inhibitors, particularly NTBC, represent promising new drugs for mosquito control. Since they only affect blood-feeding organisms, they would represent a safer and more environmentally friendly alternative to conventional neurotoxic insecticides.

Author Summary

The control of mosquitoes has been pursued in the last decades by the use of neurotoxic insecticides to prevent the spreading of dengue, zika and malaria, among other diseases. However, the selection and propagation of different mechanisms of resistance hinder the success of these compounds. New methodologies are needed for their control. Hematophagous arthropods, including mosquitoes, ingest quantities of blood that represent many times their body weight in a single meal, releasing huge amounts of amino acids during digestion. Recent studies showed that inhibition of the tyrosine catabolism pathway could be a new selective target for vector control. Thus we tested three different inhibitors of the second enzyme in the tyrosine degradation pathway as tools for mosquito control. Results showed that Nitisinone (NTBC), an inhibitor used in medicine, was the most potent of them. NTBC was lethal to Aedes aegypti when it was administered together with the blood meal and when it was topically applied. It also caused the death of Anopheles aquasalis and Culex quinquefasciatus mosquitoes, as well as field-collected Aedes populations resistant to neurotoxic insecticides, indicating that there is no cross-resistance. We discuss the possible use of NTBC as a new insecticide.
The RNA Binding Protein FMRP Promotes Myelin Sheath Growth
Authors: Doll Caleb A. , Yergert Katie M. , Appel Bruce H.
Published: June 2019

During development, oligodendrocytes in the central nervous system extend a multitude of processes that wrap axons with myelin. The highly polarized oligodendrocytes generate myelin sheaths on many different axons, which are far removed from the cell body. Neurons use RNA binding proteins to transport, stabilize, and locally translate mRNA in distal domains of neurons. Local synthesis of synaptic proteins during neurodevelopment facilitates the rapid structural and functional changes underlying neural plasticity and avoids extensive protein transport. We hypothesize that RNA binding proteins also regulate local mRNA regulation in oligodendrocytes to promote myelin sheath growth. Fragile X mental retardation protein (FMRP), an RNA binding protein that plays essential roles in the growth and maturation of neurons, is also expressed in oligodendrocytes. To determine whether oligodendrocytes require FMRP for myelin sheath development, we examinedfmr1-/-mutant zebrafish and droveFMR1expression specifically in oligodendrocytes. We found oligodendrocytes infmr1-/-mutants developed myelin sheaths of diminished length, a phenotype that can be autonomously rescued in oligodendrocytes withFMR1expression. Myelin basic protein (Mbp), an essential myelin protein, was reduced in myelin tracts offmr1-/-mutants, but loss of FMRP function did not impact the localization ofmbpatranscript in myelin. Finally, expression of FMR1-I304N, a missense allele that abrogates FMRP association with ribosomes, failed to rescuefmr1-/-mutant sheath growth and induced short myelin sheaths in oligodendrocytes of wild-type larvae. Taken together, these data suggest that FMRP promotes sheath growth through local regulation of translation.
Natural variants in C. elegans atg-5 3’UTR uncover divergent effects of autophagy on polyglutamine aggregation in different tissues
Authors: Alexander-Floyd J , Haroon S , Ying M , Entezari AA , Jaeger C , Vermulst M , Gidalevitz T
Published: June 2019

Diseases caused by protein misfolding and aggregation, in addition to cell selectivity, often exhibit variation among individuals in the age of onset, progression, and severity of disease. Genetic variation has been shown to contribute to such clinical variation. We have previously found that protein aggregation-related phenotypes in a model organism, C. elegans, can be modified by destabilizing polymorphisms in the genetic background and by natural genetic variation. Here, we identified a large modifier locus in a Californian wild strain of C. elegans, DR1350, that alters the susceptibility of the head muscle cells to polyglutamine (polyQ) aggregation, and causes an increase in overall aggregation, without changing the basal activity of the muscle proteostasis pathways known to affect polyQ aggregation. We found that the two phenotypes were genetically separable, and identified regulatory variants in a gene encoding a conserved autophagy protein ATG-5 (ATG5 in humans) as being responsible for the overall increase in aggregation. The atg-5 gene conferred a dosage-dependent enhancement of polyQ aggregation, with DR1350-derived atg-5 allele behaving as a hypermorph. Examination of autophagy in animals bearing the modifier locus indicated enhanced response to an autophagy-activating treatment. Because autophagy is known to be required for the clearance of polyQ aggregates, this result was surprising. Thus, we tested whether directly activating autophagy, either pharmacologically or genetically, affected the polyQ aggregation in our model. Strikingly, we found that the effect of autophagy on polyQ aggregation was tissue-dependent, such that activation of autophagy decreased polyQ aggregation in the intestine, but increased it in the muscle cells. Our data show that cryptic genetic variants in genes encoding proteostasis components, although not causing visible phenotypes under normal conditions, can have profound effects on the behavior of aggregation-prone proteins, and suggest that activation of autophagy may have divergent effects on the clearance of such proteins in different cell types.
Shared dynamic functional connectivity across schizophrenia, bipolar disorder and major depressive disorder
Authors: Li Chao , Xu Ke , Dong Mengshi , Wei Yange , Duan Jia , Han Shaoqiang , Feng Ruiqi , Zhang Luheng , Zhao Pengfei , Chen Yifan , Jiang Xiaowei , Wei Shengnan , Yin Zhiyang , Zhang Yifan , Chen Huafu , Tang Yanqing , Wang Fei
Published: June 2019

Dynamic functional connectivity (DFC) analysis can capture time-varying properties of connectivity and may provide further information about transdiagnostic psychopathology across major psychiatric disorders. In this study, we used resting state functional MRI and a sliding-window method to study DFC in 150 schizophrenia (SZ), 100 bipolar disorder(BD), 150 major depressive disorder (MDD), and 210 healthy controls (HC). DFC were clustered into two functional connectivity states. Significant 4-group differences in DFC were found only in state 2. Post hoc analyses showed that transdiagnostic dysconnectivity among there disorders featured decreased connectivity within visual, somatomotor, salience and frontoparietal networks. Our results suggest that decreased connectivity within both lower-order (visual and somatomotor) and higher-order (salience and frontoparietal) networks may serve as transdiagnostic marker of these disorders, and that these dysconnectivity is state-dependent. Targeting these dysconnectivity may improve assessment and treatment for patients that having more than one of these disorders at the same time.
Patch-Clamp Recording of K+ Current from Lacrimal Gland Duct Cells
Authors: Haarsma Loren D. , Ubels John L.
Published: June 2019

Electrophysiologic studies have characterized ion channels in lacrimal gland acinar cells, but due to relative paucity and inaccessibility, such studies on lacrimal gland duct cells are challenging. The duct cells are believed to secrete the high level of K+ that is present in tears. The goal of this project was to develop a method for isolation of viable, single duct cells, demonstrate their utility for patch-clamp recording and characterize the K+ channels expressed by duct cells. Exorbital lacrimal gland slices from Sprague-Dawley rats were incubated with collagenase. Under a microscope, the ducts were microdissected from the glands and then incubated with elastase and collagenase. Dispersed duct cells were plated on a cover slip coated with BD Cell-Tak. Duct cells were distinguished from acinar cells by their smaller size and lack of granularity. Whole-cell K+ currents were recorded from duct cells using the perforated-patch technique and pipettes with resistances of less than 10 MΩ. EGTA and CaCl2 in the pipette solution were adjusted to give 1 uM free Ca++. When held at −80 mV, duct cells showed K+ currents that activated at command voltages near 0 mV and reached amplitudes near 1 nA at +100 mV. Currents reached peak amplitude less than 20 ms after depolarization and did not inactivate. These currents were inactivated by holding the cells at 0 mV. Currents were blocked reversibly by TEA in the presence of Ca2+, but were not blocked by TEA in the absence of Ca2+. Currents were not affected by clotrimazole (10 uM) or Ba2+ (5 mM). A method has been established for isolation and dissociation lacrimal gland duct cells for electrophysiologic studies. These cells express a voltage-activated K+ channel that is dependent on the presence of intracellular Ca2+ and may correspond to the IKCa1 channel expressed on the apical membranes of lacrimal gland ducts.
Microplastic ingestion by a herring Opisthonema sp., in the Pacific coast of Costa Rica
Authors: Bermúdez-Guzmán Luis , Alpízar-Villalobos Crista , Gatgens-García Johan , Jiménez-Huezo Gabriel , Rodríguez-Arias Marco , Molina-Ureña Helena , Villalobos Javier , Paniagua Sergio A. , Vega-Baudrit José R. , Rojas-Jimenez Keilor
Published: June 2019

Despite there is a growing interest in studying the presence and effects of microplastics (MP) in fishes and other aquatic species, knowledge is still limited in tropical areas. In this study, we examined the presence of MP in the gastrointestinal content of 30 filter feeders of thread herring, Opisthonema complex (Clupeiformes: Clupeidae) from the Central Pacific coast of Costa Rica. We detected the presence of MP in 100% of the individuals with an average of 36.7 pieces per fish, of which 79.5% were fibers and 20.5% particles. To our knowledge, this is the first study in Costa Rica that demonstrates the presence of MP in planktivorous fishes. The effects of microplastics ingestion by O. libertate and its transit through aquatic food webs should be studied in greater detail, with greater number of sampling points at different times of the year. However, our work confirms that contamination by microplastics is having direct effects on the marine life of Costa Rica.

Capsule

This is the first multidisciplinary study in Costa Rica demonstrating the presence and nature of microplastics in the digestive tract of planktivorous fish.
All thresholds of maternal hyperglycaemia from the WHO 2013 criteria for gestational diabetes identify women with a higher genetic risk for type 2 diabetes
Authors: Hughes Alice E , Hayes M. Geoffrey , Egan Aoife M , Patel Kashyap A , Scholtens Denise M , Lowe Lynn P , Lowe William L , Dunne Fidelma P , Hattersley Andrew T , Freathy Rachel M
Published: June 2019

Background

Using genetic scores for fasting plasma glucose (FPG GS) and type 2 diabetes (T2D GS), we investigated whether the fasting, 1-hour and 2-hour glucose thresholds from the WHO 2013 criteria for gestational diabetes (GDM) have different implications for genetic susceptibility to raised fasting glucose and type 2 diabetes in women from the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) and Atlantic Diabetes in Pregnancy (DIP) studies.

Methods

Cases were divided into three subgroups: (i) FPG ≥5.1 mmol/L only, n=222; (ii) 1-hour glucose post 75 g oral glucose load ≥10 mmol/L only, n=154 (iii) 2-hour glucose ≥8.5 mmol/L only, n=73); and (iv) both FPG ≥5.1 mmol/L and either of a 1-hour glucose ≥10 mmol/L or 2-hour glucose ≥8.5 mmol/L, n=172. We compared the FPG and T2D GS of these groups with controls (n=3,091) in HAPO and DIP separately.

Results

In HAPO and DIP, the mean FPG GS in women with a FPG ≥5.1 mmol/L, either on its own or with 1-hour glucose ≥10 mmol/L or 2-hour glucose ≥8.5 mmol/L, was higher than controls (all P <0.01). Mean T2D GS in women with a raised FPG alone or with either a raised 1-hour or 2-hour glucose was higher than controls (all P <0.05). GDM defined by 1-hour or 2-hour hyperglycaemia only was also associated with a higher T2D GS than controls (all P <0.05).

Conclusions

The different diagnostic categories that are part of the WHO 2013 criteria for GDM identify women with a genetic predisposition to type 2 diabetes as well as a risk for adverse pregnancy outcomes.
Protein aggregation mediates stoichiometry of protein complexes in aneuploid cells
Authors: Brennan Christopher M. , Vaites Laura Pontano , Wells Jonathan N. , Santaguida Stefano , Paulo Joao A. , Storchova Zuzana , Harper J. Wade , Marsh Joseph A. , Amon Angelika
Published: June 2019

Aneuploidy, a condition characterized by chromosome gains and losses, causes reduced fitness and numerous cellular stresses, including increased protein aggregation. Here, we identify protein complex stoichiometry imbalances as a major cause of protein aggregation in aneuploid cells. Subunits of protein complexes encoded on excess chromosomes aggregate in aneuploid cells, which is suppressed when expression of other subunits is coordinately altered. We further show that excess subunits are either degraded or aggregate and that protein aggregation is nearly as effective as protein degradation at lowering levels of excess proteins. Our study explains why proteotoxic stress is a universal feature of the aneuploid state and reveals protein aggregation as a form of dosage compensation to cope with disproportionate expression of protein complex subunits.
Structural consequences of transforming growth factor beta-1 activation from near-therapeutic X-ray doses
Authors: Stachowski Timothy , Grant Thomas D. , Snell Edward H.
Published: June 2019

Dissociation of transforming growth factor beta-1 (TGFβ-1) from the inhibitory protein latency-associated peptide (LAP) can occur from low doses of X-ray irradiation of the LAP–TGFβ-1 complex, resulting in the activation of TGFβ-1, and can have health-related consequences. Using the tools and knowledge developed in the study of radiation damage in the crystallographic setting, small-angle X-ray scattering (SAXS) and complementary techniques suggest an activation process that is initiated but not driven by the initial X-ray exposure. LAP is revealed to be extended when not bound to TGFβ-1 and has a different structural conformation compared to the bound state. These studies pave the way for the structural understanding of systems impacted at therapeutic X-ray doses and show the potential impact of radiation damage studies beyond their original intent.
The potential benefits of using higher X-ray energies for macromolecular crystallography
Authors: Dickerson Joshua L. , Garman Elspeth F.
Published: June 2019

Using X-ray energies higher than those normally used (5–15 keV) for macromolecular X-ray crystallography (MX) at synchrotron sources can theoretically increase the achievable signal as a function of dose and reduce the rate of radiation damage. In practice, a major stumbling block to the use of higher X-ray energy has been the reduced quantum efficiency of silicon detectors as the X-ray energy increases, but hybrid photon-counting CdTe detectors are optimized for higher X-ray energies, and their performance has been steadily improving. Here the potential advantages of using higher incident beam energy together with a CdTe detector for MX are explored, with a particular focus on the advantages that higher beam energies may have for MX experiments with microbeams or microcrystals. Monte Carlo simulations are presented here which for the first time include the efficiency responses of some available X-ray detectors, as well as the possible escape of photoelectrons from the sample and their entry from surrounding material. The results reveal a `sweet spot' at an incident X-ray energy of 26 keV, and show a greater than factor of two improvement in diffraction efficiency at this energy when using microbeams and microcrystals of 5 µm or less.
Radiation damage in small-molecule crystallography: fact not fiction
Authors: Christensen Jeppe , Horton Peter N. , Bury Charles S. , Dickerson Joshua L. , Taberman Helena , Garman Elspeth F. , Coles Simon J.
Published: June 2019

Traditionally small-molecule crystallographers have not usually observed or recognized significant radiation damage to their samples during diffraction experiments. However, the increased flux densities provided by third-generation synchrotrons have resulted in increasing numbers of observations of this phenomenon. The diversity of types of small-molecule systems means it is not yet possible to propose a general mechanism for their radiation-induced sample decay, however characterization of the effects will permit attempts to understand and mitigate it. Here, systematic experiments are reported on the effects that sample temperature and beam attenuation have on radiation damage progression, allowing qualitative and quantitative assessment of their impact on crystals of a small-molecule test sample. To allow inter-comparison of different measurements, radiation-damage metrics (diffraction-intensity decline, resolution fall-off, scaling B-factor increase) are plotted against the absorbed dose. For ease-of-dose calculations, the software developed for protein crystallography, RADDOSE-3D, has been modified for use in small-molecule crystallography. It is intended that these initial experiments will assist in establishing protocols for small-molecule crystallographers to optimize the diffraction signal from their samples prior to the onset of the deleterious effects of radiation damage.
A model of industrialization and rural income distribution
Authors: Wang Yong
Published: June 2019

Purpose

The purpose of this paper is to explore how the processes of (de)industrialization and rural income distribution interact with each other and their implications for economic growth and welfare.

Design/methodology/approach

This paper takes a dynamic general-equilibrium and theoretical approach.

Findings

The author develops a dynamic general-equilibrium model to analytically characterize how (de) industrialization interacts with rural income distribution, and also explores the implications for aggregate GDP growth, the evolution of rural income distribution as well as welfare. Redistributive policies are shown to sometimes enhance GDP and welfare by boosting the production of the goods with high desirability (or productivity) but constrained by depressed demand due to income inequality, and internalizing the dynamic impact of private production and consumption decisions on future public productivities.

Practical implications

The research suggests that rural income distribution and (de)industrialization are intrinsically related, so policies or institutional distortions on one process would, in general, affect the other. Redistributive policies are shown to sometimes enhance GDP and welfare by enhancing industrialization.

Originality/value

The paper contributes to the literature of industrialization and structural change at large in several aspects. First, a key novel feature of our model is that the Engle’s law is captured by a quasi-linear utility function, which differs from the standard non-homothetic functions in this literature. Second, our paper contributes to the literature of structural change by showing how (de)industrialization works when sectorial productivity changes are endogenous. The paper also sheds light on the determination of rural income distribution and its evolution in the process of structural change and rural-urban migration.
The effects of social capital on farmers’ wellbeing in China’s undeveloped poverty-stricken areas
Authors: Ma Xiaoqiang , Wang Jiaqi , Zhao Ling , Han Jinmian
Published: June 2019

Purpose

The purpose of this paper is to investigate empirically the effects of different dimensions of social capital on the well-being of farmers in China’s undeveloped poverty-stricken areas, and study the equivalent multiple of social capital and income compensation.

Design/methodology/approach

The paper opted for an exploratory study using the open-ended approach of grounded theory, including 1,176 interviews with rural households in poverty-stricken areas in China. The data were complemented by documentary analysis. Then an econometric model of social capital and farmers’ well-being was applied to the data.

Findings

The results show that the number frequently visiting relatives, reciprocity, participation and trust level are significantly positively related to the well-being of the farmers, and the level of participation in social capital requires the most income compensation, while the level of trust comes second.

Originality/value

This paper can serve as a template for developing a useful tool that can be fitted to national or regional data for studying the effects of social capital on the well-being of farmers in poor areas or countries and for calculating the concrete equivalent multiple of social capital and income compensation.
A critical multimodal framework for reading and analyzing pedagogical materials
Authors: Huang Shin-ying
Published: June 2019

Purpose

This paper aims to propose a critical multimodal framework to understanding pedagogical materials that focuses on not only the verbal or the visual components but also the interaction between the two semiotic resources that constructs power relations as a result of intermodal interaction, and it further provides an example of an in-depth analysis of one text using this approach.

Design/methodology/approach

The paper proposes a critical multimodal framework that draws from Serafini (2010) and Royce (1998). Details about how the two works complement to form a critical multimodal framework are discussed, after which the paper analyzes one example from an English-language textbook using the proposed framework to demonstrate its strengths.

Findings

The findings highlight the power relations constructed in texts as a result of the interaction between the verbal and visual components, specifically how the visual mode functions to rationalize the power relations constructed in the verbal mode. These findings also establish the significance for considering the larger context of materials production and reception identified in the ideological perspective to appreciate how texts reflect discourses in diverse locales.

Originality/value

This paper argues that even though critical multimodality has often been discussed conceptually in L1 literacy scholarship, how to put these conceptualizations into practice has not been addressed systematically. The paper also contends that critical perspectives to understanding multimodal texts are also important in L2 English-language teaching. The critical multimodal framework proposed thus serves as a conceptual and methodological framework for multimodal reading and interpretive practices in both L1 and L2 contexts.
The future persona: a futures method to let your scenarios come to life
Authors: Fergnani Alessandro
Published: June 2019

Purpose

The purpose of this paper is to formally introduce the future persona, a futures method to let scenarios come to life. A future persona is a scenario-specific fictional individual living in the future scenario (s)he is meant to depict. The paper provides a formal, systematic and clear step-by-step guide on how to create engaging and effective future personas after a scenario planning exercise.

Design/methodology/approach

After having introduced the future persona method, tracing it back to the customer persona method in user centered design (UCD) and differentiating it from previous uses of futures characters in the futures studies literature and in other domains, an example of the creation process of four future personas based on four scenario archetypes of the futures of work is provided, illustrated with pictures and discussed.

Findings

Future personas, with their narratives and graphical illustrations, are found to be particularly useful to convey scenarios to a target audience.

Practical implications

Futures personas can be used in a scenario planning exercise to increase the clarity of scenarios in the mind of scenario planners and to let scenarios be known inside an organization.

Originality/value

Future personas can substantially enrich scenarios, increasing their liveliness, playfulness and empathy.
Providing a model for Csf according to pool boiling convection heat transfer of water/ferrous oxide nanofluid using sensitivity analysis
Authors: Salimpour Mohammad Reza , Karimi Darvanjooghi Mohammad Hossein , Abdollahi Ali , Karimipour Arash , Goodarzi Marjan
Published: June 2019

Purpose

A boiling surface with different initial roughness and under various nanoparticles volume fractions was studied in present work.

Design/methodology/approach

Develop a correlation and sensitivity analysis.

Findings

The results showed that for small (7.3 nm) and much larger (about 2,000 nm) surface roughness, compared to nanoparticle size of around 25 nm, the heat transfer rate of nanofluid diminishes relative to that of base fluid. The results also demonstrated that the boiling heat transfer rate is reduced by increasing the concentration of nanoparticles. For larger boiling surface roughness (480 nm) and nanoparticles volume fractions of less than 0.1 Vol.%, the value of heat transfer increases with the increase of nanoparticles concentration; and for those of more than 0.1 Vol.%, heat transfer rate decreases by adding more nanoparticles, significantly.

Originality/value

Finally, an equation was presented for estimating the wall superheat and the Csf coefficient in terms of mentioned parameters.
Study on fluid flow and heat transfer in fluid channel filled with KKL model-based nanofluid during natural convection using FVM
Authors: Rao Yongsheng , Shao Zehui , Rahimi Alireza , Kasaeipoor Abbas , Hasani Malekshah Emad
Published: June 2019

Purpose

A comprehensive study on the fluid flow and heat transfer in a nanofluid channel is carried out. The configuration of the channel is as like as quarter channel. The channel is filled with CuO–water nanofluid.

Design/methodology/approach

The Koo–Kleinstreuer–Li model is used to estimate the dynamic viscosity and consider the Brownian motion. On the other hand, the influence of nanoparticles’ shapes on the heat transfer rate is considered in the simulations. The channel is included with the injection pipes which are modeled as active bodies with constant temperature in the 2D simulations.

Findings

The Rayleigh number, nanoparticle concentration and the thermal arrangements of internal pipes are the governing parameters. The hydrothermal aspects of natural convection are investigation using different approaches such as average Nusselt number, total entropy generation, Bejan number, streamlines, temperature fields, local heat transfer irreversibility, local fluid friction irreversibility and heatlines.

Originality/value

The originality of this work is investigation of fluid flow, heat transfer, entropy generation and heatline visualization within a nanofluid-filled channel using a finite volume method.
Modeling heat transfer of nanofluid flow in microchannels with electrokinetic and slippery effects using Buongiorno’s model
Authors: Xu Hang , Huang Huang , Xu Xiao-Hang , Sun Qiang
Published: June 2019

Purpose

This paper aims to study the heat transfer of nanofluid flow driven by the move of channel walls in a microchannel under the effects of the electrical double layer and slippery properties of channel walls. The distributions of velocity, temperature and nanoparticle volumetric concentration are analyzed under different slip-length. Also, the variation rates of flow velocity, temperature, concentration of nanoparticle, the pressure constant, the local volumetric entropy generation rate and the total cross-sectional entropy generation are analyzed.

Design/methodology/approach

A recently developed model is chosen which is robust and reasonable from the point of view of physics, as it does not impose nonphysical boundary conditions, for instance, the zero electrical potential in the middle plane of the channel or the artificial pressure constant. The governing equations of flow motion, energy, electrical double layer and stream potential are derived with slip boundary condition presented. The model is non-dimensionalized and solved by using the homotopy analysis method.

Findings

Slip-length has significant influences on the velocity, temperature and nanoparticle volumetric concentration of the nanofluid. It also has strong effects on the pressure constant. With the increase of the slip-length, the pressure constant of the nanofluid in the horizontal microchannel decreases. Both the local volumetric entropy generation rate and total cross-sectional entropy generation rate are significantly affected by both the slip-length of the lower wall and the thermal diffusion. The local volumetric entropy generation rate at the upper wall is always higher than that around the lower wall. Also, the larger the slip-length is, the lower the total cross-sectional entropy generation rate is when the thermal diffusion is moderate.

Originality/value

The findings in this work on the heat transfer and flow phenomena of the nanofluid in microchannel are expected to make a contribution to guide the design of micro-electro-mechanical systems.
Determinants of the intention to adopt Islamic banking in a non-Islamic developing country
Authors: Bananuka Juma , Kaawaase Twaha Kigongo , Kasera Musa , Nalukenge Irene
Published: June 2019

Purpose

This paper aims to investigate the contribution of attitude, subjective norm and religiosity on the intention to adopt Islamic banking in an emerging economy like Uganda, which is a secular state that is in the early stages of adopting Islamic banking.

Design/methodology/approach

This study uses a cross-sectional and correlational research design. Usable questionnaires were received from 258 managers of their own micro businesses. A hierarchical regression analysis was used to test the hypotheses.

Findings

Results indicate that attitude and religiosity are significant determinants of the intention to adopt Islamic banking, unlike subjective norm whose predictive power is subsumed in attitude. In the absence of attitude, subjective norm is a significant determinant of intention to adopt Islamic banking. Overall, attitude, subjective norm and religiosity explain 44 per cent of the variance in the intention to adopt Islamic banking in Uganda.

Research limitations/implications

This study is cross-sectional, excluding the monitoring of changes in behavior over time. Further, the study used evidence from owner-managed micro businesses in Uganda. It is possible that these results are only applicable to Uganda’s micro businesses.

Originality/value

Islamic banking is an emerging phenomenon on the African continent, especially in Sub-Saharan Africa, where most countries are secular states. As such, there are largely no empirical studies exploring the combined contributions of attitude, subjective norm and religiosity on the intention to adopt Islamic banking in an emerging economy after the national adoption of an enabling legal framework. To the best of the researchers’ knowledge, this is the first study that carries out this task.