bluuebunny/crossref_metadata_2025 huggingface dataset:
2.7 Å cryo-EM structure of vitrified M. musculus H-chain apoferritin from 200 keV “screening microscope”
Authors: Hamdi Farzad , Tüting Christian , Semchonok Dmitry A. , Kyrilis Fotis L. , Meister Annette , Skalidis Ioannis , Schmidt Lisa , Parthier Christoph , Stubbs Milton T. , Kastritis Panagiotis L.
Published: August 2019

Here we present the structure of mouse H-chain apoferritin at 2.7 Å (FSC=0.143) solved by single particle cryogenic electron microscopy (cryo-EM) using a 200 kV device. Data were collected using a compact, two-lens illumination system with a constant power objective lens, without the use of energy filters or aberration correctors. Coulomb potential maps reveal clear densities for main chain carbonyl oxygens, residue side chains (including alternative conformations) and bound solvent molecules. We argue that the advantages offered by (a) the high electronic and mechanical stability of the microscope, (b) the high emission stability and low beam energy spread of the high brightness Field Emission Gun (x-FEG), (c) direct electron detection technology and (d) particle-based Contrast Transfer Function (CTF) refinement have contributed to achieving resolution close to the Rayleigh limit. Overall, we show that basic electron optical settings for automated cryo-electron microscopy imaging, widely thought of as a “screening cryo-microscope”, can be used to determine structures approaching atomic resolution.

Highlights

The 2.7 Å structure of mouse apoferritin was solved using a 200 keV screening cryo-microscope

The apoferritin reconstruction was resolved without an energy filter, aberration correctors, or constant-power condenser lenses

Comparison to available crystallographic and cryo-EM structures from high-end cryo-microscopes demonstrates consistency in resolved water molecules, metals and side chain orientations

Although radiation damage is more prominent at 200 keV compared to 300 keV, this type of instrumentation is more accessible to research laboratories due to its compactness and simplicity
Gametophytes and embryo ontogeny: understanding the reproductive calendar ofCypripedium japonicumThunb. (Cypripedoideae, Orchidaceae)
Authors: Ghimire Balkrishna , Son Sung Won , Kim Jae Hyun , Jeong Mi-Jin
Published: August 2019

Among the flowering plants, the gametophyte development and reproductive biology of orchids is particularly poorly understood.Cypripedium japonicumis a perennial herb, native to East Asia. Due to its limited distribution, the species is included in the Endangered category of the IUCN Red List. Light microscopy and SEM methods were used to study the development of the gametes and embryo. The complete reproductive cycle was developed based on our observations. Anther development begins under the soil and meiosis of pollen cells begins 3 weeks before anthesis, possibly during early April. The megaspore mother cells develop just after pollination in early May and mature in mid–late June. The pattern of embryo sac formation is bisporic and there are six nuclei. Triple fertilization results in the endosperm nucleus. A globular embryo is formed after multiple cell division and 9 weeks after pollination the entire embryo sac is occupied by embryo. Overall comparisons of the features of gametophyte and embryo development inC. japonicumsuggest that previous reports on the embryology ofCypripediumare not sufficient to characterize the entire genus. Based on the available information a reproductive calendar showing the key reproductive events leading to embryo formation has been prepared.

Highlight

Manual pollination, reproductive biology and seed development process inCypripedium japonicumThunb., a lady’s slipper orchid endemic to East Asia
A potential cortical precursor of visual word form recognition in untrained monkeys
Authors: Rajalingham Rishi , Kar Kohitij , Sanghavi Sachi , Dehaene Stanislas , DiCarlo James J.
Published: August 2019

Skilled human readers can readily recognize written letters and letter strings. This domain of visual recognition, known as orthographic processing, is foundational to human reading, but it is unclear how it is supported by neural populations in the human brain. Behavioral research has shown that non-human primates (baboons) can learn to distinguish written English words from pseudo-words (lexical decision), successfully generalize that behavior to novel strings, and exhibit behavioral error patterns that are consistent with humans. Thus, non-human primate models, while not capturing the entirety of human reading abilities, may provide a unique opportunity to investigate the neuronal mechanisms underlying orthographic processing. Here, we investigated the neuronal representation of letters and letter strings in the ventral visual stream of naive macaque monkeys, and asked to what extent these representations could support visual word recognition. We recorded the activity of hundreds of neurons at the top two levels of the ventral visual form processing pathway (V4 and IT) while monkeys passively viewed images of letters, English words, and non-word letter strings. Linear decoders were used to probe whether those neural responses could support a battery of orthographic processing tasks such as invariant letter identification and lexical decision. We found that IT-based decoders achieved baboon-level performance on these tasks, with a pattern of errors highly correlated to the previously reported primate behavior. This capacity to support orthographic processing tasks was also present in the high-layer units of state-of-the-art artificial neural network models of the ventral stream, but not in the low-layer representations of those models. Taken together, these results show that the IT cortex of untrained monkeys contains a reservoir of precursor features from which downstream brain regions could, with some supervised instruction, learn to support the visual recognition of written words. This suggests that the acquisition of reading in humans did not require a full rebuild of visual processing, but rather the recycling of a brain network evolved for other visual functions.
A supervised learning framework for chromatin loop detection in genome-wide contact maps
Authors: Salameh Tarik J. , Wang Xiaotao , Song Fan , Zhang Bo , Wright Sage M. , Khunsriraksakul Chachrit , Yue Feng
Published: August 2019

Accurately predicting chromatin loops from genome-wide interaction matrices such as Hi-C data is critical to deepen our understanding of proper gene regulation events. Current approaches are mainly focused on searching for statistically enriched dots on a genome-wide map. However, given the availability of a wide variety of orthogonal data types such as ChIA-PET, GAM, SPRITE, and high-throughput imaging, a supervised learning approach could facilitate the discovery of a comprehensive set of chromatin interactions. Here we present Peakachu, a Random Forest classification framework that predicts chromatin loops from genome-wide contact maps. Compared with current enrichment-based approaches, Peakachu identified more meaningful short-range interactions. We show that our models perform well in different platforms such as Hi-C, Micro-C, and DNA SPRITE, across different sequencing depths, and across different species. We applied this framework to systematically predict chromatin loops in 56 Hi-C datasets, and the results are available at the 3D Genome Browser (www.3dgenome.org).
Analysis of the effectiveness of sub-sensory electrical noise stimulation during visuomotor adaptations in different visual feedback conditions
Authors: Castronovo Anna Margherita , Giles Doran Ciara , Holden Méabh , Severini Giacomo
Published: August 2019

Sub-sensory electrical noise stimulation has been shown to improve motor performance in tasks that rely principally on proprioceptive feedback. During the generation of movements such as reaching, proprioceptive feedback combines dynamically with visual feedback. It is still unclear whether boosting proprioceptive information in tasks where proprioception mixes with vision can influence motor performance at all, either by improving or worsening it. To better understand this point, we tested the effect of electrical noise stimulation applied superficially to the muscle spindles during four different experiments consisting of isometric reaching tasks under different visual feedback conditions. The first experiment (n=40) consisted of a reach-and-hold task where subjects had to hold a cursor on a target for 30 seconds and had visual feedback removed 10 seconds into the task. Subjects performed 30 repetitions of this task with different stimulation levels, including no stimulation. We observed that trials in which the stimulation was present, displayed smaller movement variability. Moreover, we observed a positive correlation between the level of stimulation and task performance. The other experiments consisted of three versions of an isometric visuomotor adaptation task where subjects were asked to reach to random targets in less than 1.5 seconds (otherwise incurring in negative feedback) while overcoming a 45° clockwise rotation in the mapping between the force exerted and the movement of the cursor. The three experiments differed in the visual feedback presented to the subjects, with one group (n=20) performing the experiment with full visual feedback, one (n=10) with visual feedback restricted only to the beginning of the trajectory and one (n=10) without visual feedback of the trajectory. All subjects performed their experiment twice, with and without stimulation. We did not observe substantial effects of the stimulation when visual feedback was present (either completely or partially). We observed a limited effect of the stimulation in the absence of visual feedback consisting in a significant smaller number of negative-feedback trials in the first block of the adaptation phase. Our results suggest that sub-sensory stimulation can be beneficial when proprioception is the main feedback modality but mostly ineffective in tasks where visual feedback is actively employed.
Structural basis for Rab8a GTPase recruitment of RILPL2 via LRRK2 phosphorylation of switch 2
Authors: Waschbüsch Dieter , Purlyte Elena , Pal Prosenjit , McGrath Emma , Alessi Dario R. , Khan Amir R.
Published: August 2019

Rab8a GTPase is associated with the dynamic regulation of membrane protrusions in polarized cells. Rab8a is one of several Rab-family GTPases that are substrates of leucine-rich repeat kinase 2 (LRRK2), a serine/threonine kinase that is linked to inherited Parkinson’s disease. Rab8a is phosphorylated at T72 (pT72) in its switch 2 helix and the post-translational modification facilitates phospho-Rab8a (pRab8a) interactions with RILPL2, which subsequently regulates ciliogenesis. Here we report the crystal structure of pRab8a in complex with the phospho-Rab binding domain of RILPL2. The complex is a heterotetramer with RILPL2 forming a central α-helical dimer that bridges two pRab8a molecules. The N-termini of the α-helices cross over to form an X-shaped cap (X-cap) that enables electrostatic interactions between Arg residues from RILPL2 and the phosphate moiety from pT72. RILPL2 residues in the X-cap that are critical for pRab8a binding are conserved in the RILP family of effector proteins. We find that JIP3 and JIP4 also interact specifically with LRRK2-phosphorylated Rab10, suggesting a general mode of recognition for phosphorylated Rab GTPases by phospho-specific effectors.
Salient images: Evidence for a component process architecture for visual imagination
Authors: Murphy Charlotte , Ping Ho Nerissa Siu , Bernhardt Boris , Macrae C. Neil , Sormaz Mladen , Vatansever Deniz , Jefferies Elizabeth , Smallwood Jonathan
Published: August 2019

The ability to visualise different people and places in imagination is a core element of human cognition. Contemporary neuroimaging research highlights regions of primary visual cortex as important in instantiating images in the mind’s eye. Here we combine task-based functional magnetic resonance imaging with measures of intrinsic brain organisation to show the ventral attention, or salience, network, also plays an important role in visual imagination. In a task-based study we replicated prior observations of regions of medial occipital cortex, including Brodmann Area 17, showing greater neural activity during imagination than when perceiving similar stimuli. In addition, we found regions of the ventral attention network, and in particular right dorsolateral prefrontal cortex (BA 9/46), were activated by the same acts of imagination. In a subsequent resting-state study, we demonstrated medial occipital cortex regions form a functional network with regions of the ventral attention network that were also active during imagination. Furthermore, this pattern was maximised in an overlapping region of right dorsolateral prefrontal cortex for individuals whose self-reported imagery had stronger negative affect. Together these data suggest visual imagination relies on functional interactions between regions of primary visual cortex with the ventral attention system, and in particular, with a region of right dorsolateral prefrontal cortex.
Use of short-term high energy dietary for estimating transcriptional profiling of liver tissues in sheep
Authors: Yang Shaohua , Guo Yunxia , He Chengshi , Liu Yueqin , Zhang Yingjie
Published: August 2019

This study aimed to evaluate if short-term high energy dietary has any stimulatory effects on liver function and metabolic status in sheep. The experiment was carried out using 30 Dorset×Han crossbred ewes (age, 9 ± 0.6 months; weight, 36.58 ± 2.56kg) allocated into two treatments, the control group (DE 11.72 MJ/d; DP 79.71 g/d) and the high energy group (DE18.75 MJ/d; DP 108.44 g/d), respectively. Experiment lasted 20 days, including 10 d for adaption. Blood samples of these ewes were collected to detect the concentrations of glucose, insulin, leptin, and cholesterol, respectively. Then, animals were sacrificed and optimal liver samples subjected to explore the genome-wide transcriptome analysis. Results showed that the weight gain was significantly increased in the high energy group, compared with those in the control group (p< 0.01). The concentrations of glucose, insulin, leptin, and cholesterol were also influenced by short-term nutritional supplementation at different levels. Subsequently, 622 differentially expressed genes were identified by pairwise comparison. Of these, 271 genes were down regulated while 351 genes were up regulated. qRT-PCR analysis of 10 randomly selected genes were consistent with the sequencing results. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed 12 DEGs (includingPDK4, ABCA9, ALDH6A1, SLC45A3, G0S2, PPARGC1, GHRHR, GHR, DGKI, SOCS2, LPIN1andCSKMT) were significantly enriched in cellular carbohydrate catabolic and metabolic process, phosphorelay sensor and phosphotransferase kinase activity, generation of precursor metabolites and energy, lipid metabolic and transport process, positive regulation of cellular metabolic process, acyl-CoA desaturase activity and monosaccharide metabolic process. Additionally, we concluded an interaction network related to energy metabolism, which might be contributed to elucidate the precise molecular mechanisms of related genes associated with energy metabolism in the liver tissues of sheep.
Proteomic profiling ofMycobacterium tuberculosisculture filtrate identifies novel O-glycosylated proteins
Authors: Tucci Paula , Portela Madelón , Chetto Carlos Rivas , González-Sapienza Gualberto , Marín Mónica
Published: August 2019

Despite being the subject of intensive research, tuberculosis, caused byMycobacterium tuberculosis, remains at present the leading cause of death from an infectious agent. Secreted and cell wall proteins interact with the host and play important roles in pathogenicity. These proteins have been explored as candidate diagnostic markers, potential drug targets or vaccine antigens, and special attention has been given to the role of their post-translational modifications. With the purpose of contributing to the proteomic characterization of this important pathogen including an O-glycosylation profile analysis, we performed a shotgun analysis of culture filtrate proteins ofM. tuberculosisbased on a liquid nano-HPLC tandem mass spectrometry and a label-free spectral counting normalization approach for protein quantification. We identified 1314M. tuberculosisproteins in culture filtrate and found that the most abundant proteins belong to the extracellular region or cell wall compartment, and that the functional categories with higher protein abundance factor were virulence, detoxification and adaptation, and cell wall and cell processes. In culture filtrate, 140 proteins were predicted to contain one of the three types of bacterial N-terminal signal peptides. Besides, various proteins belonging to the ESX secretion systems, and to the PE and PPE families, secreted by the type VII secretion system using nonclassical secretion signals, were also identified. O-glycosylation was identified as a frequent modification, being present in 108 proteins, principally lipoproteins and secreted immunogenic antigens. We could identify a group of proteins consistently detected in previous studies, most of which were highly abundant proteins. Interestingly, we also provide proteomic evidence for 62 novel O-glycosylated proteins, aiding to the glycoproteomic characterization of relevant antigenic membrane and exported proteins.
Acute characterization of tissue and functional deficits in a clinically translatable pig model of ischemic stroke
Authors: Kaiser Erin E. , Waters Elizabeth S. , Fagan Madison M. , Scheulin Kelly M. , Platt Simon R. , Jeon Julie H. , Fang Xi , Kinder Holly A. , Shin Soo K. , Duberstein Kylee J. , Park Hea J. , West Franklin D.
Published: August 2019

The acute stroke phase is a critical time frame used to evaluate stroke severity, therapeutic options, and prognosis while also serving as a major target for the development of diagnostics. To better understand stroke pathophysiology and to enhance the development of treatments, our group developed a translational pig ischemic stroke model. In this study, the evolution of acute ischemic stroke tissue damage, immune response, and functional deficits were further characterized in the pig model. Stroke was induced by middle cerebral artery occlusion in Landrace pigs. At 24 hours post-stroke, magnetic resonance imaging revealed a decrease in ipsilateral diffusivity and an increase in hemispheric swelling and intracranial hemorrhage resulting in notable midline shift. Stroke negatively impacted white matter integrity leading to decreased fractional anisotropy. Similar to acute clinical patients, stroked pigs showed a reduction in circulating lymphocytes and a surge in neutrophils and band cells. Functional responses corresponded with structural changes with reduced exploration in open field testing and impairments in spatiotemporal gait parameters. This novel, acute ischemia characterization provides important insights into tissue and functional level changes in a pig model that can be used to identify treatment targets and future testing of therapeutics and diagnostics.
Successes of artemisinin elicitation in low-artemisinin producing Artemisia annua cell cultures constrained by repression of biosynthetic genes
Authors: Yee Melissa Kam Yit , Ping Winnie Yap Soo
Published: August 2019

The sesquiterpene phytolactone derived from Artemisia annua, artemisinin is associated with a variety of novel biological properties, such as immunoregulatory and anticancer effects, and therapeutic applications, apart from its main function as an antimalarial drug. Emerging from the fact that artemisinin production in planta occurs in trace amounts and its compartmentalized synthesis, the irregular agricultural supply often results in market fluctuations and reductions in artemisinin inventory. Further improvement in artemisinin production calls for approaches that act in a supplementary manner, filling the agricultural production gap. Here we investigated the elicitation efficiency of ultraviolet B (UV-B) and dimethyl sulfoxide (DMSO) independently on a low-artemisinin producing (LAP) chemotype of the species A. annua. The exposure of cell suspension cultures to short-term UV-B radiation and DMSO treatment did not result in significant changes in artemisinin yield. The lack of stimulation has been associated with: (i) the general lack of cytodifferentiation of cell cultures; (ii) negative feedback regulation of artemisinin biosynthesis; and (iii) artemisinin sequestration by cellular detoxification. Further molecular analysis revealed the repression of key genes ADS, DBR2 and ALDH1 which affected artemisinin synthesis. This study provides insights into the complexity of stress-induced responses of A. annua cell suspension cultures in relation to metabolic processes (transportation, accumulation and degradation of secondary products) which are important for artemisinin formation.
Cep97 Is Required For Centriole Structural Integrity And Cilia Formation In Drosophila
Authors: Dobbelaere Jeroen , Schmidt-Cernohorska Marketa , Huranova Martina , Slade Dea , Dammermann Alexander
Published: August 2019

Centrioles are highly elaborate microtubule-based structures responsible for the formation of centrosomes and cilia. Despite considerable variation across species and tissues, within any given tissue their size is essentially constant [1, 2]. While the diameter of the centriole cylinder is set by the dimensions of the inner scaffolding structure of the cartwheel [3], how centriole length is set so precisely and stably maintained over many cell divisions is not well understood. Cep97 and CP110 are conserved proteins that localize to the distal end of centrioles and have been reported to limit centriole elongation in vertebrates [4, 5]. Here, we examine Cep97 function in Drosophila melanogaster. We show that Cep97 is essential for formation of full-length centrioles in multiple tissues of the fly. We further identify the microtubule deacetylase Sirt2 as a Cep97 proximity interactor. Deletion of Sirt2 likewise affects centriole size. Interestingly, so does deletion of the acetylase Atat1, indicating that loss of stabilizing acetyl marks impairs centriole integrity. Cep97 and CP110 were originally identified as inhibitors of cilia formation in vertebrate cultured cells [6] and loss of CP110 is a widely used marker of basal body maturation. In contrast, in Drosophila Cep97 is only transiently removed from basal bodies and loss of Cep97 strongly impairs ciliogenesis. Collectively, our results support a model whereby Cep97 functions as part of a protective cap that acts together with the microtubule acetylation machinery to maintain centriole stability, essential for proper function in cilium biogenesis.
Extent of N-terminus exposure by altered long-range interactions of monomeric alpha-synuclein determines its aggregation propensity
Authors: Stephens Amberley D. , Zacharopoulou Maria , Moons Rani , Fusco Giuliana , Seetaloo Neeleema , Chiki Anass , Hooper Philippa J. , Mela Ioanna , Lashuel Hilal A. , Phillips Jonathan J , Simone Alfonso De , Sobott Frank , Schierle Gabriele S. Kaminski
Published: August 2019

As an intrinsically disordered protein, monomeric alpha synuclein (aSyn) constantly reconfigures and probes the conformational space. Long-range interactions across the protein maintain its solubility and mediate this dynamic flexibility, but also provide residual structure. Certain conformations lead to aggregation prone and non-aggregation prone intermediates, but identifying these within the dynamic ensemble of monomeric conformations is difficult. Herein, we used the biologically relevant calcium ion to investigate the conformation of monomeric aSyn in relation to its aggregation propensity. By using calcium to perturb the conformational ensemble, we observe differences in structure and intra-molecular dynamics between two aSyn C-terminal variants, D121A and pS129, and the aSyn familial disease mutants, A30P, E46K, H50Q, G51D, A53T and A53E, compared to wild-type (WT) aSyn. We observe that the more exposed the N-terminus and the beginning of the NAC region are, the more aggregation prone monomeric aSyn conformations become. N-terminus exposure occurs upon release of C-terminus interactions when calcium binds, but the level of exposure is specific to the aSyn mutation present. There was no correlation between single charge alterations, calcium affinity, or the number of ions bound on aSyn’s aggregation propensity, indicating that sequence or post-translation modification (PTM)-specific conformational differences between the N- and C-termini and the specific local environment mediate aggregation propensity instead. Understanding aggregation prone conformations of monomeric aSyn and the environmental conditions they form under will allow us to design new therapeutics targeted to the monomeric protein, to stabilise aSyn in non-aggregation prone conformations, by either preserving long-range interactions between the N- and C-termini or by protecting the N-terminus from exposure.
Therapeutically actionable PAK4 is amplified, overexpressed and involved in bladder cancer progression
Authors: Chandrashekar Darshan S. , Chakravarthi Balabhadrapatruni V. S. K. , Robinson Alyncia D. , Anderson Joshua C. , Agarwal Sumit , Hodigere Balasubramanya Sai Akshaya , Eich Marie-Lisa , Bajpai Akhilesh Kumar , Davuluri Sravanthi , Guru Maya S. , Guru Arjun S. , Naik Gurudatta , Della Manna Deborah L. , Acharya Kshitish K. , Carskadon Shannon , Manne Upender , Crossman David K. , Ferguson James E. , Grizzle William E. , Palanisamy Nallasivam , Willey Christopher D. , Crowley Michael R. , Netto George J , Yang Eddy S. , Varambally Sooryanarayana , Sonpavde Guru
Published: August 2019

Muscle-invasive bladder carcinomas (MIBCs) are aggressive genitourinary malignancies. Disease incidence and survival rates vary based on aggressiveness and treatment options. Metastatic urothelial carcinoma of the bladder is generally incurable by current chemotherapy and leads to early mortality. For a minority (∼20%) of patients, T-cell checkpoint inhibitors provide durable benefits following prior platinum therapy. Recent studies have identified molecular subtypes of MIBCs with different sensitivities to frontline therapy, suggesting heterogeneity in these tumors and pointing to the importance of molecular characterization of MIBCs to provide effective treatment. We have performed multi-omic profiling of the kinome to identify therapeutic targets that are overexpressed in a subset of BLCAs. Our analyses revealed amplification and overexpression of P21 (RAC1) activated kinase 4 (PAK4) in a subset of BLCAs. For these tumors, multiplex kinase assay profiling identified corresponding PAK4 target substrates. By performing experiments using cultured bladder cancer cells, we confirmed the role of PAK4 in BLCA cell proliferation and invasion. Furthermore, our studies showed that a PAK4 inhibitor was effective in curtailing growth of BLCA cells. Transcriptomic analyses identified elevated expression of another kinase, Protein Tyrosine Kinase 6 (PTK6), upon treatment with a PAK4 inhibitor. Similarly, RNA interference of PAK4 led to elevated expression of PTK6. Treatment with a combination of kinase inhibitors (vandetanib and dasatinib) showed enhanced sensitivity compared to either drug alone. Thus, PAK4 may be therapeutically actionable for a subset of MIBC patients with amplified and/or overexpressed PAK4 in their tumors. Our results also indicate that combined inhibition of PAK4 and PTK6 may overcome resistance to PAK4. These observations warrant clinical investigations with selected BLCA patients.
Targeted stimulation of human orbitofrontal networks disrupts outcome-guided behavior
Authors: Howard James D. , Reynolds Rachel , Smith Devyn E. , Voss Joel L. , Schoenbaum Geoffrey , Kahnt Thorsten
Published: August 2019

Outcome-guided behavior requires knowledge about the current value of expected outcomes. Such behavior can be isolated in the reinforcer devaluation task, which assesses the ability to infer the current value of rewards after devaluation. Animal lesion studies demonstrate that orbitofrontal cortex (OFC) is necessary for normal behavior in this task, but a causal role for human OFC in outcome-guided behavior has not been established. Here we used sham-controlled non-invasive continuous theta-burst stimulation (cTBS) to temporarily disrupt human OFC network activity prior to devaluation of food odor rewards in a between-subjects design. Subjects in the sham group appropriately avoided Pavlovian cues associated with devalued food odors. However, subjects in the stimulation group persistently chose those cues, even though devaluation of food odors themselves was unaffected by cTBS. This behavioral impairment was mirrored in changes in resting-stated functional magnetic resonance imaging (rs-fMRI) activity, such that subjects in the stimulation group exhibited reduced global OFC network connectivity after cTBS, and the magnitude of this reduction was correlated with choices after devaluation. These findings demonstrate the feasibility of indirectly targeting the human OFC with non-invasive cTBS, and indicate that OFC is specifically required for inferring the value of expected outcomes.
Electrochemical corrosion behavior of HVOF sprayed WC–12Co coating on H13 hot work mould steel
Authors: Weicheng Kong , Hui Shen , Jiaxu Gao , Jie Wu , Yuling Lu
Published: August 2019

Purpose

This study aims to investigate the electrochemical corrosion performance of high velocity oxygen fuel (HVOF) sprayed WC–12Co coating in 3.5 Wt.% NaCl solution, which provided a guiding significance on the corrosion resistance of H13 hot work mould steel.

Design/methodology/approach

A WC–12Co coating was fabricated on H13 hot work mould steel using a HVOF, and the electrochemical corrosion behaviors of WC–12Co coating and substrate in 3.5 Wt.% NaCl solution was measured using open circuit potential (OCP), potentiodynamic polarization curve (PPC) and electrochemical impedance spectroscopy (EIS) tests.

Findings

The OCP and PPC of WC–12Co coating positively shift than those of substrate, its corrosion tendency and corrosion rate decrease to enhance its corrosion resistance. The curvature radius of capacitance curve on the WC–12Co coating is larger than that on the substrate, and the impedance and polarization resistance of WC–12Co coating increase faster than those of substrate, which reduces the corrosion process.

Originality/value

The electrochemical corrosion behaviors of WC–12Co coating and substrate in 3.5 Wt.% NaCl solution is first measured using OCP, PPC and EIS tests, which improve the electrochemical corrosion resistance of H13 hot work mould steel.
Antecedents of continuous change in educational organizations
Authors: Kondakci Yasar , Zayim Kurtay Merve , Caliskan Omer
Published: August 2019

Purpose

Drawing on and theorizing continuous change, the purpose of this paper is to investigate the antecedents of continuous change behavior in schools. Relying on conceptual discussions about organizational change (OC), three sets of variables including context (workload, participatory management, trust), process (knowledge sharing, social interaction) and outcome (job satisfaction) were identified as antecedents of continuous change.

Design/methodology/approach

To test the predictive value of the antecedents for continuous change, a correlational study was design and structural equation modeling was used to test the direct and indirect relationships among study variables. The data were collected from a sample of 648 primary and secondary public school teachers.

Findings

The results showed that context, outcome, and process factors function through direct and indirect paths to contribute to the prediction of continuous change behavior. Moreover, knowledge sharing either directly or indirectly played a central role in the prediction of continuous change behavior.

Research limitations/implications

These results suggested that a widened knowledge base provides the basis for ongoing experimentation with, alteration, and modification of work categories in schools. Providing such factors in schools seems to facilitate the ongoing improvement of work practices in schools, even in the absence of a planned change intervention.

Originality/value

This study is one of the first empirical studies tested the predictive value of antecedents of continuous change in school organizational context, where OC is the norm and change failures are very common.
Internationalization market and higher education field: institutional perspectives
Authors: Alsharari Nizar Mohammad
Published: August 2019

Purpose

The purpose of this paper is to explore the internationalization market of higher education (HE) globally and HE field. It examines the internationalization status of HE in Jordan as influenced by institutional perspectives as an example from developing countries.

Design/methodology/approach

This paper adopts a quantitative research design that includes a statistical and SWOT analysis of HE in Jordan. Data were collected from different courses: documents and archival records, websites analysis, surveys, interviews with professors and administrators, and an SWOT analysis as well as TOWS matrix. The latter has been constructed as a picture of internationalized education in the Jordan that can be used as a basis for decision making and strategies for higher education institutions (HEIs).

Findings

The study findings reveal that it is important for Jordan to endorse itself as an “education hub” in the Middle East and to educate its community to the level of skills required by globalization. The challenges of internationalizing HE are revealed by the SWOT analysis and TOWS matrix that highlight a wide range of opportunities and strengths that encourages the Jordan HE system to accelerate internationalization. The opportunities include overall improvement in the quality of education, the diffusion of technology and creating a globally competent workforce. The internationalization status in Jordan HE is still in its embryonic stage. The HE should take serious steps toward the internationalization including admission of international students, foreign postgraduate students, international accreditation, global ranking, online education and smart education. These steps will help the universities leaders to improve their universities position internationally and financially.

Research limitations/implications

The findings reveal implications for HE policy and strategy in the development of internationalized HE in the Jordan. The study shows how SWOT analysis and TOWS matrix can provide a solid platform against which particular case studies can be measured in terms of opportunities for and challenges of development. It also provides institutional perspectives with practical implications, focusing on some of the critical issues in this developing field for HE policy and strategy alike. A major threat to the Jordan progress in developing its HE sector identified in this study is external accreditation being seen as a signal of high quality, when more realistic standards are perhaps more relevant to the local population.

Originality/value

The paper is one of the very few studies in the area of the internationalization of HE in the Jordan that can contribute to the sustainability of the international dimension of HEIs. The opportunities and threats recognized in this paper can inform strategy for more balanced development of the Jordan’s internationalized HE, and for raising the quality of education overall.
Housing satisfaction in a traditional neighborhood of Izmit, Turkey
Authors: Erdogan Nevnihal , Kisa Ovali Pınar , Kayapinar Özgur
Published: August 2019

Purpose

The purpose of this paper was to investigate housing satisfaction in a traditional neighborhood of Izmit, Turkey. According to this purpose, it was investigated whether the perceived living conditions (PLC) were mediating the effect on participants’ general housing satisfaction caused by satisfaction with the perceived quality of facilities (FQP), satisfaction with performance of local authorities (LA), satisfaction with social relations (SR) and satisfaction with physical surrounding (PS) in the Topçular neighborhood of Izmit District in Kocaeli, Turkey.

Design/methodology/approach

According to the hypotheses developed within the framework of the theoretical model, by using structural equation modeling (SEM), first, the direct relations between the variables were tested (PLC → overall housing satisfaction (OHS); PS, SR, LA → PLC; FQP → LA), then the indirect relationships between the variables were analyzed with the mediated role of OHS (PS, SR, LA → OHS → PLC).

Findings

The results show that all factors affected the OHS through the PLC. In conclusion, as the living conditions of the individual living in the neighborhood improve, the conditions take an active role in the relationship between the OHS and the satisfaction with the other relevant factors in the neighborhood, namely, PS, SR and performance of LA. In this relationship, it is seen that the satisfaction with PS has a negative effect, while the satisfaction with SR and satisfaction with the performance of LA have positive effects.

Research limitations/implications

The study was applied only to Turkey’s Izmit Province. Research may also be applied to other cities apart from those in Turkey. A small sample was also used in the study. Reaching a wider sampling for SEM can lead to different results.

Practical implications

Planners and designers should consider satisfaction – including various factors involved in planning, designing and refurbishing the neighborhoods – as the most important design data.

Social implications

The results of this study show that living conditions had an active role in the relationship between OHS and certain factors in the neighborhood: satisfaction with PS, SR and performance of LA. This study offers a framework to LA such as policymakers and urban planners to develop relevant and effective strategies and to improve dissatisfactory conditions in new and peripheral areas.

Originality/value

The originality of the paper is based on revealing the factors affecting the housing satisfaction of people living in the province of Izmit. This study offers a framework to LA such as policymakers and urban planners to develop relevant and effective strategies and to improve dissatisfactory conditions in new and peripheral areas.
Communication disorders among Syrian refugee children in Beqaa, Lebanon
Authors: Salam Alia , McIntire Russell K. , Pilling Lucille B.
Published: August 2019

Purpose

The purpose of this paper is to identify the severity of certain communication disorders (CD) in a sample of Syrian refugee children. There are a limited number of studies about CD among refugee children.

Design/methodology/approach

Over a period of 22 months, 161 cases of CD – not caused by motor or structural disorders – were seen at a Mental Health Clinic in Beqaa, Lebanon. The authors calculated descriptive statistics (frequencies and percentages) and bivariate statistics to identify relationships between CD, demographics and school enrollment among cases.

Findings

Ages ranged between 3 and 16 years with a mean of 6.91. Male to female ratio was 1.6:1. The most prevalent category of CD was speech, followed by expressive language, then receptive language. Parents reported behavioral or emotional problems in 38 percent of the cases; emotional problems, mainly anxiety, were much more common than behavioral problems. Enrollment in school was associated with a lower number of impairments and less severe speech and language impairments.

Originality/value

The results highlight the importance of early detection and intervention among Syrian refugee children. Schools can alleviate some psychological issues that compound CD by enhancing resilient behaviors and providing social support. They can also implement measures for detection and intervention.
Intersectionality in the narratives of black women in computing through the education and workforce pipeline
Authors: Yamaguchi Ryoko , Burge Jamika D.
Published: August 2019

Purpose

The purpose of this study is to investigate the narratives of 93 Black women in computing in the USA to identify salient themes that are at the intersection of race and gender in the field of computer science.

Design/methodology/approach

The study uses a multi-method approach with a survey to describe the sample and a series of focus groups for in-depth analysis of themes. The qualitative methodology uses a grounded theory and consensual qualitative research approach with a research team that includes computer scientists and social scientists to collect and analyze data. Given the highly technical field of computer science and the intersectional experiences of the participants, this approach was optimal to capture and code data through the lens of Black women in computing.

Findings

The authors found four main themes that represented specific needs for Black women in the computing community. The first is the importance of linking Black women in computing (i.e. their recruitment, retention and career growth) to the bottom line of organizational and personal accountability. The second is effective cultural and educational supports for Black women in computing across pathways, starting in middle school. The third is to provide leadership development as a part of their educational and workplace experience. The fourth is a collection of empirical research and scholarship about and for Black women as a part of the computing literature.

Originality/value

Black women comprise one of the most underrepresented subgroups in the area of computer science in the USA. There is very little research about Black women in computing. To promote broadened participation in computing, there is a critical need to understand the narratives of successful Black women in the space.
Multiple components of plant diversity loss determine herbivore phylogenetic diversity in a subtropical forest experiment
Authors: Wang Ming‐Qiang , Li Yi , Chesters Douglas , Anttonen Perttu , Bruelheide Helge , Chen Jing‐Ting , Durka Walter , Guo Peng‐Fei , Härdtle Werner , Ma Keping , Michalski Stefan G. , Schmid Bernhard , von Oheimb Goddert , Wu Chun‐Sheng , Zhang Nai‐Li , Zhou Qing‐Song , Schuldt Andreas , Zhu Chao‐Dong
Published: August 2019

Plant diversity loss can alter higher trophic‐level communities via non‐random species interactions, which in turn may cascade to affect key ecosystem functions. These non‐random linkages might be best captured by patterns of phylogenetic diversity, which take into account co‐evolutionary dependencies. However, lack of adequate phylogenetic data of higher trophic levels hampers our mechanistic understanding of biodiversity relationships in species‐rich ecosystems.

We used DNA barcoding to generate data on the phylogenetic diversity of lepidopteran caterpillars in a large‐scale forest biodiversity experiment in subtropical China. We analysed how different metrics of lepidopteran phylogenetic diversity (Faith's PD, MPD, MNTD) and taxonomic diversity were influenced by multiple components of tree diversity (taxonomic, functional, phylogenetic).

Our data from six sampling periods represent 7,204 mitochondrial cytochrome c oxidase subunit I (COI) sequences of lepidopteran larvae, clustered into 461 molecular operational taxonomic units. Lepidopteran abundance, the effective number of species (irrespective of the focus on rare or common species) and Faith's PD and MPD (reflecting basal evolutionary splits), but not MNTD (reflecting recent evolutionary splits), significantly increased with experimentally manipulated tree species richness. Lepidopteran MNTD decreased with increasing tree MNTD. Path analyses showed that tree phylogenetic and functional diversity explained part, but not all of the effects of tree species richness on lepidopteran diversity. Importantly, tree diversity effects on lepidopteran diversity were to a large extent indirect, operating via changes in lepidopteran abundance.

Synthesis. Our study shows that evolutionary dependencies determine the response of herbivore communities to changes in host plant diversity. Incorporating a wider range of diversity metrics both at the level of producers and consumers can thus help to develop a more comprehensive understanding of the functional consequences of biodiversity change across trophic levels. Moreover, the dependence of trophic linkages on herbivore abundances underlines the need to address the consequences of current declines in insect abundances for ecosystem structure and functioning.
Mitochondrial‐encoded endonucleases drive recombination of protein‐coding genes in yeast
Authors: Wu Baojun , Hao Weilong
Published: August 2019

Mitochondrial recombination in yeast is well recognized, yet the underlying genetic mechanisms are not well understood. Recent progress has suggested that mobile introns in mitochondrial genomes (mitogenomes) can facilitate the recombination of their corresponding intron‐containing genes through a mechanism known as intron homing. As many mitochondrial genes lack introns, there is a critical need to determine the extent of recombination and underlying mechanism of intron‐lacking genes. This study leverages yeast mitogenomes to address these questions. In Saccharomyces cerevisiae, the 3′‐end sequences of at least three intron‐lacking mitochondrial genes exhibit elevated nucleotide diversity and recombination hotspots. Each of these 3′‐end sequences is immediately adjacent to or even fused as overlapping genes with a stand‐alone endonuclease. Our findings suggest that SAEs are responsible for recombination and elevated diversity of adjacent intron‐lacking genes. SAEs were also evident to drive recombination of intron‐lacking genes in Lachancea kluyveri, a yeast species that diverged from S. cerevisiae more than 100 million years ago. These results suggest SAEs as a common driver in recombination of intron‐lacking genes during mitogenome evolution. We postulate that the linkage between intron‐lacking gene and its adjacent endonuclease gene is the result of co‐evolution.
Incomplete Clearinghouse Mandates
Authors: Baker Colleen M.
Published: August 2019

In the 2007–08 financial crisis, over‐the‐counter (OTC) derivatives triggered the collapse of colossal financial institutions. In response, global policy makers instituted clearinghouse mandates. As a result, all standardized OTC derivatives must now use clearinghouses, and global financial market stability now depends upon these institutions. Yet certain underlying legal and regulatory structures threaten to undermine clearinghouse stability, particularly were a significant clearinghouse to become distressed. This article argues that the clearinghouse mandates are incomplete in that they fail to reform these problematic arrangements.

As with electric utilities, the lights at the financial market infrastructures known as clearinghouses must always be on. Yet the legal frameworks for handling a distressed clearinghouse, the problem of clearinghouse recovery, and resolution, remain uncertain. This article advances debate on this issue. It argues that recovery, a private market restructuring process, can be conceptualized as a bargaining game dependent upon time‐critical cooperation between a clearinghouse and members. This article uses transaction cost economics to demonstrate, however, that certain underlying legal and regulatory structures could work at cross‐purposes to this necessary cooperation, and actually increase its cost. Based upon this analysis, it proposes reforms designed to ensure that parties’ incentives promote efficient recovery. In the absence of efficient recovery frameworks, the path of a distressed, significant clearinghouse is likely to resemble that of the government‐backed mortgage lenders whose fate more than ten years after their entry into conservatorship remains uncertain. This article aims to help avoid a repeat of this history.