bluuebunny/crossref_metadata_2025 huggingface dataset:
What the Networks Tell us about Serial and Parallel Processing
Authors: Tremblay Antoine , Asp Elissa , Johnson Anne , Migdal Malgorzata Zarzycka , Bardouille Tim , Newman Aaron J.
Published: June 2016

A large literature documenting facilitative effects for high frequency complex words and phrases has led to proposals that high frequency phrases may be stored in memory rather than constructed on-line from their component parts (similarly to high frequency complex words). To investigate this, we explored language processing during a novel picture description task. Using the magneto-encephalographam (MEG) technique and generalised additive mixed-effects modelling, we characterised the effects of the frequency of use of single words as well as two-, three-, and four-word sequences (N-grams) on brain activity during the pre-production stage of unconstrained overt picture description. We expected amplitude responses to be modulated by N-gram frequency such that if N-grams were stored we would see a corresponding reduction or flattening in amplitudes as frequency increased. We found that while amplitude responses to increasing N-gram frequencies corresponded with our expectations about facilitation, the effect appeared at low frequency ranges and for single words only in the phonological network. We additionally found that high frequency N-grams elicited activity increases in some networks, which may be signs of competition or combination depending on the network. Moreover, this effect was not reliable for single word frequencies. These amplitude responses do not clearly support storage for high frequency multi-word sequences. To probe these unexpected results, we turned our attention to network topographies and the timing. We found that, with the exception of an initial ‘sentence’ network, all the networks aggregated peaks from more than one domain (e.g. semantics and phonology). Moreover, although activity moved serially from anterior ventral networks to dorsal posterior networks during processing, as expected in combinatorial accounts, sentence processing and semantic networks ran largely in parallel. Thus, network topographies and timing may account for (some) facilitative effects associated with frequency. We review literature relevant to the network topographies and timing and briefly discuss our results in relation to current processing and theoretical models.
An assessment of residual stress mitigation strategies for laser clad deposits
Authors: Martinez Hurtado A. , Francis J. A. , Stevens N. P. C.
Published: June 2016

Laser cladding can be used for reclamation or for improving the corrosion resistance of engineering components. However, the process introduces substantial levels of residual stress, which can exacerbate corrosion. In this study, the effectiveness of different residual stress mitigation strategies was investigated. Laser clad overlays were produced by melting an austenitic stainless steel powder onto either an austenitic stainless steel or a mild steel substrate. Residual stresses were measured, using the hole-drilling technique, in the as-clad condition as well as after either laser shock peening (LSP) or post-weld heat treatment (PWHT). Samples were then subjected to corrosion testing. In all cases, LSP delayed the onset of corrosion cracks. However, PWHT was only effective when the substrate and overlay materials matched.

This paper is part of a Themed Issue on Measurement, modelling and mitigation of residual stress.
Endogenous nitric oxide mediates He-Ne laser-induced adaptive responses in salt stressed-tall fescue leaves
Authors: Li Yongfeng , Gao Limei , Han Rong
Published: June 2016

The aim of this study was to investigate the role of endogenous nitric oxide in protective effects of He–Ne laser on salt stressed-tall fescue leaves. Salt stress resulted in significant increases of membrane injury, reactive oxygen species (ROS) production, polyamine accumulation, and activities of SOD, POD, and APX, while pronounced decreases of antioxidant contents, CAT activity and intracellular Ca2+ concentration in seedlings leaves. He–Ne laser illumination caused a distinct alleviation of cellular injury that was reflected by the lower MDA amounts, polyamine accumulation and ROS levels at the stress period. In contrast, the laser treatment displayed a higher Ca2+ concentration, antioxidant amounts, NO release, antioxidant enzyme, and NOS activities. These responses could be blocked due to the inhibition of NO biosynthesis by PTIO (NO scavenger) or LNNA (NOS inhibitor). The presented results demonstrated that endogenous NO might be involved in the progress of He–Ne laser-induced plant antioxidant system activation and ROS degradation in order to enhance adaptive responses of tall fescue to prolonged saline conditions.
Inhibitory effects of caffeine on gustatory plasticity in the nematode Caenorhabditis elegans
Authors: Urushihata Takuya , Takuwa Hiroyuki , Higuchi Yukako , Sakata Kazumi , Wakabayashi Tokumitsu , Nishino Asuka , Matsuura Tetsuya
Published: June 2016

The effects of caffeine on salt chemotaxis learning were investigated using the nematode Caenorhabditis elegans. To estimate the degree of salt chemotaxis learning, nematodes were placed in a mixed solution of NaCl and caffeine, and then the chemotaxis index of NaCl was obtained from the nematodes placed on agar medium after pre-exposure to caffeine concentrations of 0.01, 0.1, 0.3, and 1.0%. Locomotor activity and preference behavior for caffeine were also estimated under these caffeine conditions. Nematodes pre-exposed to 0.3% caffeine showed inhibition of salt chemotaxis learning. Additional experiments indicated that nematodes showed a preference response to the middle concentration of caffeine (0.1%), with preference behavior declining in the 0.3% caffeine condition. Stable locomotor activity was observed under 0.01–0.3% caffeine conditions. These results suggest that salt chemotaxis learning with 0.3% caffeine is useful for investigating the effects of caffeine on learning in nematodes.
Potential involvement of drought-induced Ran GTPase CLRan1 in root growth enhancement in a xerophyte wild watermelon
Authors: Akashi Kinya , Yoshimura Kazuya , Kajikawa Masataka , Hanada Kouhei , Kosaka Rina , Kato Atsushi , Katoh Akira , Nanasato Yoshihiko , Tsujimoto Hisashi , Yokota Akiho
Published: June 2016

Enhanced root growth is known as the survival strategy of plants under drought. Previous proteome analysis in drought-resistant wild watermelon has shown that Ran GTPase, an essential regulator of cell division and proliferation, was induced in the roots under drought. In this study, two cDNAs were isolated from wild watermelon, CLRan1 and CLRan2, which showed a high degree of structural similarity with those of other plant Ran GTPases. Quantitative RT-PCR and promoter-GUS assays suggested that CLRan1 was expressed mainly in the root apex and lateral root primordia, whereas CLRan2 was more broadly expressed in other part of the roots. Immunoblotting analysis confirmed that the abundance of CLRan proteins was elevated in the root apex region under drought stress. Transgenic Arabidopsis overexpressing CLRan1 showed enhanced primary root growth, and the growth was maintained under osmotic stress, indicating that CLRan1 functions as a positive factor for maintaining root growth under stress conditions.
Perverse curves and mirror symmetry
Authors: Ruddat Helge
Published: June 2016

This work establishes a subtle connection between mirror symmetry for Calabi-Yau threefolds and that of curves of higher genus. The linking structure is what we call a perverse curve. We show how to obtain such from Calabi-Yau threefolds in the Batyrev mirror construction and prove that their Hodge diamonds are related by the mirror duality.
R.JIVE for exploration of multi-source molecular data
Authors: O’Connell Michael J. , Lock Eric F.
Published: June 2016

Summary: The integrative analysis of multiple high-throughput data sources that are available for a common sample set is an increasingly common goal in biomedical research. Joint and individual variation explained (JIVE) is a tool for exploratory dimension reduction that decomposes a multi-source dataset into three terms: a low-rank approximation capturing joint variation across sources, low-rank approximations for structured variation individual to each source and residual noise. JIVE has been used to explore multi-source data for a variety of application areas but its accessibility was previously limited. We introduce R.JIVE, an intuitive R package to perform JIVE and visualize the results. We discuss several improvements and extensions of the JIVE methodology that are included. We illustrate the package with an application to multi-source breast tumor data from The Cancer Genome Atlas.

Availability and Implementation: R.JIVE is available via the Comprehensive R Archive Network (CRAN) under the GPLv3 license: https://cran.r-project.org/web/packages/r.jive/.

Contact:  elock@umn.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Signal apparition for simultaneous source wavefield separation
Authors: Robertsson Johan O.A. , Amundsen Lasse , Pedersen Åsmund Sjøen
Published: June 2016

A new method for discrete sampling of signals is presented with specific applications to the reconstruction of recorded interfering wavefields from two or more sources excited simultaneously at discrete positions along lines. By utilizing a periodic sequence of source signatures along one of the source lines, the corresponding wavefield becomes separately visible in a part of the spectral domain where it can be isolated, processed and subtracted from the interfering wavefields. As a result, interfering wavefields from multiple sources recorded at a single location can be fully separated from each other. The concept is referred to as signal apparition which we suggest refers to ‘the act of becoming visible’. It may find applications in a wide range of disciplines relying on wave experimentation, such as acoustic, seismic and electromagnetic imaging of the Earth's interior for instance to significantly enhance resolution of subsurface images.
Triglyceride/HDL ratio and its impact on the risk of diabetes mellitus development during ART
Authors: Squillace Nicola , Lorenzini Patrizia , Lapadula Giuseppe , Bandera Alessandra , Cozzi-Lepri Alessandro , Rusconi Stefano , Puoti Massimo , Castagna Antonella , Antinori Andrea , Gori Andrea , d'Arminio Monforte Antonella
Published: June 2016

Objectives

Our primary aim was to study diabetes mellitus (DM) arising during combination ART (cART) and to attempt to identify associations between these cases and triglycerides (TRG) and the TRG to HDL-cholesterol (TRG/HDL) ratio. Our secondary aim was to analyse the association between DM development and hepatic fibrosis.

Methods

This was a retrospective cohort study. Patients from the Icona Foundation study initiating first-line cART between 1997 and 2013 were selected and observed until new-onset DM or most recent clinical follow-up. The predictive value of TRG and TRG/HDL ratio levels on DM was evaluated using multivariable Poisson regression models.

Results

Three-thousand, five-hundred and forty-six patients (males, 73.7%; median age, 38 years; median BMI, 23.1 kg/m2; and hepatitis C virus antibody positive, 22.1%) were included. Of these, 80 developed DM over 13 911 person-years of follow-up (PYFU), corresponding to 5.7 cases per 1000 PYFU (95% CI = 4.6–7.1). At multivariable analysis, latest TRG/HDL ratio, when high, was associated with significant increases in DM risk [relative risk (RR) = 1.63; 95% CI = 1.32–2.01 per 10 points higher], while current TRG, in contrast, was associated with new-onset DM only at crude analysis. Advanced liver fibrosis (defined as fibrosis-4 index >3.25) was also shown to be an independent risk factor for DM (RR = 2.91; 95% CI = 1.10–7.72).

Conclusions

High TRG/HDL ratio predicted risk of new-onset DM, independently of other traditional risk factors. Furthermore, our findings suggest that advanced hepatic fibrosis, estimated using the fibrosis-4 score, could provide an additional predictor for DM.
Which veterans enroll in a VA health information exchange program?
Authors: Dixon Brian E , Ofner Susan , Perkins Susan M , Myers Laura J , Rosenman Marc B , Zillich Alan J , French Dustin D , Weiner Michael , Haggstrom David A.
Published: June 2016

Objective: To characterize patients who voluntarily enrolled in an electronic health information exchange (HIE) program designed to share data between Veterans Health Administration (VHA) and non-VHA institutions.

Materials and Methods: Patients who agreed to participate in the HIE program were compared to those who did not. Patient characteristics associated with HIE enrollment were examined using a multivariable logistic regression model. Variables selected for inclusion were guided by a health care utilization model adapted to explain HIE enrollment. Data about patients’ sociodemographics (age, gender), comorbidity (Charlson index score), utilization (primary and specialty care visits), and access (distance to VHA medical center, insurance, VHA benefits) were obtained from VHA and HIE electronic health records.

Results: Among 57 072 patients, 6627 (12%) enrolled in the HIE program during its first year. The likelihood of HIE enrollment increased among patients ages 50–64, of female gender, with higher comorbidity, and with increasing utilization. Living in a rural area and being unmarried were associated with decreased likelihood of enrollment.

Discussion and Conclusion: Enrollment in HIE is complex, with several factors involved in a patient’s decision to enroll. To broaden HIE participation, populations less likely to enroll should be targeted with tailored recruitment and educational strategies. Moreover, inclusion of special populations, such as patients with higher comorbidity or high utilizers, may help refine the definition of success with respect to HIE implementation.
Computer use, language, and literacy in safety net clinic communication
Authors: Ratanawongsa Neda , Barton Jennifer L , Lyles Courtney R , Wu Michael , Yelin Edward H , Martinez Diana , Schillinger Dean
Published: June 2016

Objective: Patients with limited health literacy (LHL) and limited English proficiency (LEP) experience suboptimal communication and health outcomes. Electronic health record implementation in safety net clinics may affect communication with LHL and LEP patients.

We investigated the associations between safety net clinician computer use and patient-provider communication for patients with LEP and LHL.

Materials and Methods: We video-recorded encounters at 5 academically affiliated US public hospital clinics between English- and Spanish-speaking patients with chronic conditions and their primary and specialty care clinicians. We analyzed changes in communication behaviors (coded with the Roter Interaction Analysis System) with each additional point on a clinician computer use score, controlling for clinician type and visit length and stratified by English proficiency and health literacy status.

Results: Greater clinician computer use was associated with more biomedical statements (+12.4, P = .03) and less positive affect (−0.6, P < .01) from LEP/LHL patients. In visits with patients with adequate English proficiency/health literacy, greater clinician computer use was associated with less positive patient affect (−0.9, P < .01), fewer clinician psychosocial statements (−3.5, P < .05), greater clinician verbal dominance (+0.09, P < .01), and lower ratings on quality of care and communication.

Conclusion: Higher clinician computer use was associated with more biomedical focus with LEP/LHL patients, and clinician verbal dominance and lower ratings with patients with adequate English proficiency and health literacy.

Discussion: Implementation research should explore interventions to enhance relationship-centered communication for diverse patient populations in the computer era.
An electronic documentation system improves the quality of admission notes: a randomized trial
Authors: Jamieson Trevor , Ailon Jonathan , Chien Vince , Mourad Ophyr
Published: June 2016

Objective: There are concerns that structured electronic documentation systems can limit expressivity and encourage long and unreadable notes. We assessed the impact of an electronic clinical documentation system on the quality of admission notes for patients admitted to a general medical unit.

Methods: This was a prospective randomized crossover study comparing handwritten paper notes to electronic notes on different patients by the same author, generated using a semistructured electronic admission documentation system over a 2-month period in 2014. The setting was a 4-team, 80-bed general internal medicine clinical teaching unit at a large urban academic hospital. The quality of clinical documentation was assessed using the QNOTE instrument (best possible score = 100), and word counts were assessed for free-text sections of notes.

Results: Twenty-one electronic-paper note pairs (42 notes) written by 21 authors were randomly drawn from a pool of 303 eligible notes. Overall note quality was significantly higher in electronic vs paper notes (mean 90 vs 69, P < .0001). The quality of free-text subsections (History of Present Illness and Impression and Plan) was significantly higher in the electronic vs paper notes (mean 93 vs 78, P < .0001; and 89 vs 77, P = .001, respectively). The History of Present Illness subsection was significantly longer in electronic vs paper notes (mean 172.4 vs 92.4 words, P = .0001).

Conclusions: An electronic admission documentation system improved both the quality of free-text content and the overall quality of admission notes. Authors wrote more in the free-text sections of electronic documents as compared to paper versions.
Alert override as a habitual behavior – a new perspective on a persistent problem
Authors: Baysari Melissa T , Tariq Amina , Day Richard O , Westbrook Johanna I
Published: June 2016

Quantifying alert override has been the focus of much research in health informatics, with override rate traditionally viewed as a surrogate inverse indicator for alert effectiveness. However, relying on alert override to assess computerized alerts assumes that alerts are being read and determined to be irrelevant by users. Our research suggests that this is unlikely to be the case when users are experiencing alert overload. We propose that over time, alert override becomes habitual. The override response is activated by environmental cues and repeated automatically, with limited conscious intention. In this paper we outline this new perspective on understanding alert override. We present evidence consistent with the notion of alert override as a habitual behavior and discuss implications of this novel perspective for future research on alert override, a common and persistent problem accompanying decision support system implementation.
Vision in our three-dimensional world
Authors: Parker Andrew J.
Published: June 2016

Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
Stereoscopic depth constancy
Authors: Guan Phillip , Banks Martin S.
Published: June 2016

Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
Effects of cortical damage on binocular depth perception
Authors: Bridge Holly
Published: June 2016

Stereoscopic depth perception requires considerable neural computation, including the initial correspondence of the two retinal images, comparison across the local regions of the visual field and integration with other cues to depth. The most common cause for loss of stereoscopic vision is amblyopia, in which one eye has failed to form an adequate input to the visual cortex, usually due to strabismus (deviating eye) or anisometropia. However, the significant cortical processing required to produce the percept of depth means that, even when the retinal input is intact from both eyes, brain damage or dysfunction can interfere with stereoscopic vision. In this review, I examine the evidence for impairment of binocular vision and depth perception that can result from insults to the brain, including both discrete damage, temporal lobectomy and more systemic diseases such as posterior cortical atrophy.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
The neural basis of depth perception from motion parallax
Authors: Kim HyunGoo R. , Angelaki Dora E. , DeAngelis Gregory C.
Published: June 2016

In addition to depth cues afforded by binocular vision, the brain processes relative motion signals to perceive depth. When an observer translates relative to their visual environment, the relative motion of objects at different distances (motion parallax) provides a powerful cue to three-dimensional scene structure. Although perception of depth based on motion parallax has been studied extensively in humans, relatively little is known regarding the neural basis of this visual capability. We review recent advances in elucidating the neural mechanisms for representing depth-sign (near versus far) from motion parallax. We examine a potential neural substrate in the middle temporal visual area for depth perception based on motion parallax, and we explore the nature of the signals that provide critical inputs for disambiguating depth-sign.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
Neural architectures for stereo vision
Authors: Parker Andrew J. , Smith Jackson E. T. , Krug Kristine
Published: June 2016

Stereoscopic vision delivers a sense of depth based on binocular information but additionally acts as a mechanism for achieving correspondence between patterns arriving at the left and right eyes. We analyse quantitatively the cortical architecture for stereoscopic vision in two areas of macaque visual cortex. For primary visual cortex V1, the result is consistent with a module that is isotropic in cortical space with a diameter of at least 3 mm in surface extent. This implies that the module for stereo is larger than the repeat distance between ocular dominance columns in V1. By contrast, in the extrastriate cortical area V5/MT, which has a specialized architecture for stereo depth, the module for representation of stereo is about 1 mm in surface extent, so the representation of stereo in V5/MT is more compressed than V1 in terms of neural wiring of the neocortex. The surface extent estimated for stereo in V5/MT is consistent with measurements of its specialized domains for binocular disparity. Within V1, we suggest that long-range horizontal, anatomical connections form functional modules that serve both binocular and monocular pattern recognition: this common function may explain the distortion and disruption of monocular pattern vision observed in amblyopia.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
Small or far away? Size and distance perception in the praying mantis
Authors: Nityananda Vivek , Bissianna Geoffrey , Tarawneh Ghaith , Read Jenny
Published: June 2016

Stereo or ‘3D’ vision is an important but costly process seen in several evolutionarily distinct lineages including primates, birds and insects. Many selective advantages could have led to the evolution of stereo vision, including range finding, camouflage breaking and estimation of object size. In this paper, we investigate the possibility that stereo vision enables praying mantises to estimate the size of prey by using a combination of disparity cues and angular size cues. We used a recently developed insect 3D cinema paradigm to present mantises with virtual prey having differing disparity and angular size cues. We predicted that if they were able to use these cues to gauge the absolute size of objects, we should see evidence for size constancy where they would strike preferentially at prey of a particular physical size, across a range of simulated distances. We found that mantises struck most often when disparity cues implied a prey distance of 2.5 cm; increasing the implied distance caused a significant reduction in the number of strikes. We, however, found no evidence for size constancy. There was a significant interaction effect of the simulated distance and angular size on the number of strikes made by the mantis but this was not in the direction predicted by size constancy. This indicates that mantises do not use their stereo vision to estimate object size. We conclude that other selective advantages, not size constancy, have driven the evolution of stereo vision in the praying mantis.

This article is part of the themed issue ‘Vision in our three-dimensional world’.
Lepbase: the Lepidopteran genome database
Authors: Challi Richard J , Kumar Sujai , Dasmahapatra Kanchon K , Jiggins Chris D , Blaxter Mark
Published: June 2016

As the generation and use of genomic datasets is becoming increasingly common in all areas of biology, the need for resources to collate, analyse and present data from independent (Tier 1) species-level genome projects into well supported clade-oriented (Tier 2) databases and provide a mechanism for these data to be propagated to pan-taxonomic (Tier 3) databases is becoming more pressing. Lepbase is a Tier 2 genomic resource for the Lepidoptera, supporting a research community using genomic approaches to understand evolution, speciation, olfaction, behaviour and pesticide resistance in a wide range of target species. Lepbase offers a core set of tools to make genomic data widely accessible including an Ensembl genome browser, text and sequence homology searches and bulk downloads of consistently presented and formatted datasets. As a part of the taxonomic community that we serve, we are working directly with Lepidoptera researchers to prioritise analyses and add tools that will be of most value to current research questions.
The Developmental Basis of Stomatal Density and Flux
Authors: Sack Lawren , Buckley Thomas N.
Published: June 2016

Equations for stomatal density and maximum theoretical stomatal conductance as functions of stomatal initiation rate, epidermal cell size, and stomatal size enable scaling from development to flux.
Diminished electron density in the Vaska-type rhodium(I) complextrans-[Rh(NCBH3)(CO)(PPh3)2]
Authors: Galding M. R. , Virovets A. V. , Kazakov I. V. , Scheer M. , Smirnov S. N. , Timoshkin A. Y.
Published: June 2016

Vaska-type complexes,i.e. trans-[RhX(CO)(PPh3)2] (Xis a halogen or pseudohalogen), undergo a range of reactions and exhibit considerable catalytic activity. The electron density on the RhIatom in these complexes plays an important role in their reactivity. Many cyanotrihydridoborate (BH3CN−) complexes of Group 6–8 transition metals have been synthesized and structurally characterized, an exception being the rhodium(I) complex. Carbonyl(cyanotrihydridoborato-κN)bis(triphenylphosphine-κP)rhodium(I), [Rh(NCBH3)(CO)(C18H15P)2], was prepared by the metathesis reaction of sodium cyanotrihydridoborate withtrans-[RhCl(CO)(PPh3)2], and was characterized by single-crystal X-ray diffraction analysis and IR,1H,13C and11B NMR spectroscopy. The X-ray diffraction data indicate that the cyanotrihydridoborate ligand coordinates to the RhIatom through the N atom in atransposition with respect to the carbonyl ligand; this was also confirmed by the IR and NMR data. The carbonyl stretching frequency ν(CO) and the carbonyl carbon1JC–Rhand1JC–Pcoupling constants of the Cipsoatoms of the triphenylphosphine groups reflect the diminished electron density on the central RhIatom compared to the parenttrans-[RhCl(CO)(PPh3)2] complex.
A study of the planarity of the pyrrolone fragment in 2-isopropyl-2,3-dihydro-1H-isoindol-1-one
Authors: Donkeng Dazie Joel , Liška Alan , Ludvík Jiří , Fábry Jan , Dušek Michal
Published: June 2016

Orthophthalaldehyde (o-phthalaldehyde, OPA) is an aromatic dialdehyde bearing two electron-withdrawing carbonyl groups. The reactions of OPA with primary amines are broadly applied for the synthesis of important heterocyclic compounds with biological relevance. A number of such reactions have been investigated recently and several structures of condensation products have been reported, however, the complex reaction mechanism is still not fully understood and comprises concurrent as well as consecutive reactions. The reaction products depend on the primary amine which reacts with OPA, the reaction environment (solvent) and the proportion of the reactants. The title molecule, C11H13NO, the product of the reaction of OPA with isopropylamine, contains a five-membered pyrrole C4N ring with a carbonyl substituent, which forms part of the isoindolinone unit. Though this pyrrole ring contains one C atom in thesp3-hybridized state, it is fairly planar. The title molecule has been compared with similar structures retrieved from the Cambridge Structural Database in order to study this phenomenon. The planarity of this fragment has been explained by the presence of partially delocalized C—C, C—N and C—O bonds, and by an inner angle in the planar pentagonal ring (∼108°), which is close to the ideal tetrahedral value for thesp3-hybridized state of the constituent C atom. Due to this propitious angle, this C atom can be present in states intermediate betweensp3- andsp2-hybridized in different structures, while still maintaining the planarity of the ring. There are only weak intermolecular C—H...O hydrogen bonds and C—H...π-electron ring interactions in the structure. In particular, it is the pyrrole ring which is involved in these interactions.
Influence of anions, pH and coating on the localized corrosion behavior of AZ31 magnesium alloy in physiological environments
Authors: Hu Qian , Liu Jing , Huang Feng
Published: June 2016

Purpose

The purpose of this paper was to clarify the influence of H2PO4-, HCO3-, pH increase and phosphate coating on corrosion rate and localized corrosion tendency of AZ31 magnesium alloy.

Design/methodology/approach

The corrosion behavior of AZ31 magnesium alloy in physiological environments was investigated by hydrogen evolution collection measurements, electrochemical techniques and by use of a three-dimensional digital microscope.

Findings

H2PO4- and HCO3- have corrosion inhibition effects on AZ31 magnesium alloy in normal saline solutions. After immersing for 54 h, the surface undulations decrease from 100 to about 60 μm and 45 μm. The average corrosion rate decreased with increasing pH value. The localized corrosion tendency, however, increased significantly. CaHPO4·2H2O [dicalcium phosphate dehydrate (DCPD)] coating could decrease the initial icorr of AZ31 substrate in Hank’s solution. With partial dissolution of the coating, localized corrosion was readily evident on the AZ31 substrate surface, and a large corrosion pit with depth of over 350 μm appeared. The combined effect of the presence of inhibited ions, the increase in pH during corrosion process and the DCPD coating caused the decrease in the average corrosion rate while enhancing the localized corrosion tendency, resulting in the observed localized attack.

Originality/value

The paper provides an essential insight into the localized corrosion mechanism of AZ31 magnesium alloy in physiological environments.
Experimental study of inhibitor containing sulfur for mild steel in hydrochloric acid
Authors: Ding Yao , Luo Zhengtang , Liu Dong
Published: June 2016

Purpose

The purpose of this paper is to use Dextrofosfomysin levophenethylamine salt to prepare HEHSPN-(Na)2 (HSPN), a new corrosion inhibitor containing sulfur.

Design/methodology/approach

The inhibition efficiency for Q235 steel in hydrochloric acid has been evaluated by weight-loss test, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Surface studies were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).

Findings

The results show that inhibition efficiency of HSPN increases with an increase in concentration. Adsorption conforms to Flory–Huggins uniform temperature equation, which is multi-molecular layer adsorption and belongs to physical adsorption.

Originality/value

This paper is intended to be added to the family of papers that deal with green corrosion inhibitors which are highly efficient and can be used in the area of corrosion prevention and control.
Experimental study on the corrosion testing of a buried metal pipeline by transient electromagnetic method
Authors: Hu Bo , Yu Runqiao , Liu Jian
Published: June 2016

Purpose

This paper aims to clarify the transient electromagnetic method used for the nondestructive testing of the corrosion of an in-service buried metal pipeline in trenchless state.

Design/methodology/approach

The paper designed corrosion models indoor and infield for testing. A method for calculating the residual wall thickness of metal pipelines was also proposed. The calculation method was verified by the test results. In the test, the receiving probe was improved by the addition of a Mn-Zn ferrite core. The amplitudes of the test results obviously increased, and the calculation accuracy was improved.

Findings

The paper states that the transient electromagnetic method can detect the uniform corrosion distribution of a certain section of a pipeline. A multi-channel profile of the induced electromotive force and the calculated values of the residual wall thickness can be used to confirm the position and degree of corrosion defects, respectively.

Research limitations/implications

The transient electromagnetic method is more effective for large-area corrosion than for localized corrosion (pitting).

Practical implications

The paper includes implications for the development of nondestructive testing method of the corrosion of an in-service buried metal pipeline.

Originality/value

This paper proved the feasibility and reliability of using transient electromagnetic method to test the corrosion of a buried metal pipeline based on experimental study.
The role of drug as corrosion inhibitor for mild steel surface characterization by SEM, AFM, and FTIR
Authors: Khan Md. Zaved Hossain , Aziz Md. Abdul , Hasan Md. Rafiul , Al-Mamun Md. Rashid
Published: June 2016

Purpose

The purpose of this study is to understand the inhibitor behavior of specific drug against mild steel corrosion and their adsorption mechanism on the surface.

Design/methodology/approach

Corrosion rates are influenced by the formation of inhibitor aggregates at the mild steel surface. Detail surface characterizations of mild steel have been studied before and after adsorption of drugs in 1N HCl solution. Scanning electron microscopy, atomic force microscopy and Fourier transform infrared spectroscopy were used to examine the effect of drug adsorption on steel surface.

Findings

Scanning electron microscopy analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors. Atomic force microscopy visualization confirmed the formation of protective layer on steel surface, resulting in the decrease in surface roughness with corrosion rates. The nature of metal surface has been analyzed by Fourier transform infrared spectroscopy.

Originality/value

The findings of this study will help us to understand the interaction of specific drugs with mild steel surface and their potential inhibition mechanism.
Antecedents of voluntary corporate governance disclosure: a post-2007/08 financial crisis evidence from the influential UK Combined Code
Authors: Elmagrhi Mohamed H. , Ntim Collins G. , Wang Yan
Published: June 2016

Purpose

The purpose of this study is to investigate the level of compliance with, and disclosure of, good corporate governance (CG) practices among UK publicly listed firms and consequently ascertain whether board characteristics and ownership structure variables can explain observable differences in the extent of voluntary CG compliance and disclosure practices.

Design/methodology/approach

This study uses one of the largest data sets to-date on compliance and disclosure of CG practices from 2008 to 2013 containing 120 CG provisions drawn from the 2010 UK Combined Code relating to 100 UK listed firms to conduct multiple regression analyses of the determinants of voluntary CG disclosures. A number of additional estimations, including two stage least squares, fixed-effects and lagged structures, are conducted to address the potential endogeneity issue and test the robustness of the findings.

Findings

The results suggest that there is a substantial variation in the levels of compliance with, and disclosure of, good CG practices among the sampled UK firms. The authors also find that firms with larger board size, more independent outside directors and greater director diversity tend to disclose more CG information voluntarily, whereas the level of voluntary CG compliance and disclosure is insignificantly related to the existence of a separate CG committee and institutional ownership. Additionally, the results indicate that block ownership and managerial ownership negatively affect voluntary CG compliance and disclosure practices. The findings are fairly robust across a number of econometric models that sufficiently address various endogeneity problems and alternative CG indices. Overall, the findings are generally consistent with the predictions of neo-institutional theory.

Originality/value

This study extends, as well as contributes to, the extant CG literature by offering new evidence on compliance with, and disclosure of, good CG recommendations contained in the 2010 UK Combined Code following the 2007/2008 global financial crisis. This study also advances the existing literature by offering new insights from a neo-institutional theoretical perspective of the impact of board and ownership mechanisms on voluntary CG compliance and disclosure practices.
Board of directors and financial transparency and disclosure. Evidence from Italy
Authors: Torchia Mariateresa , Calabrò Andrea
Published: June 2016

Purpose

The purpose of this paper is to examine the link between board of directors’ composition (independent directors’ ratio, board size, CEO-duality) and financial transparency and disclosure (T&D).

Design/methodology/approach

The paper analyzes board composition and financial T&D of Italian listed companies using multiple linear regression analysis.

Findings

The results of this paper show a significant link between board composition and the level of financial T&D. In particular, the authors found a positive and significant relationship between the independent directors’ ratio and the level of financial T&D and a negative relationship between board size and the level of financial T&D.

Research limitations/implications

While this paper focuses on a sample of 100 Italian listed companies, the authors acknowledge the importance of extending the results to other national context and to other type of firms (e.g. non-listed firms or SMEs). Moreover, while this paper concerns the amount of information disclosed by firms, it does not look at the quality or accuracy of disclosure.

Practical implications

This paper reveals the importance of evaluating the effectiveness of corporate governance mechanisms (such as board composition) in enhancing the level of financial T&D. Indeed, the authors provide some indications to firms to improve their internal governance mechanisms (e.g. the importance of high proportion of independent directors and of small- and medium-sized boards of directors).

Originality/value

This paper provides interesting insights to firms which are under pressure to improve the level of information to stakeholders. Moreover, has the level of information that is not legally required vary among companies and countries, the authors shed light on a context characterized by high level of ownership concentration, where firms can experience different types of conflict of interests.
Sustainability certification schemes: evaluating their effectiveness and adaptability
Authors: Mori Junior Renzo , Franks Daniel M. , Ali Saleem H.
Published: June 2016

Purpose

New sustainability certification schemes (SCS) with different scope, governance structure and operating practice are fast emerging. This rapid growth and divergence in metrics has resulted in questions about the effectiveness of such schemes. Although this practice has been growing fast, to date, there are no reviews comprehensively synthesising the literature regarding SCS’ main flaws, challenges and improvement opportunities. This paper aims to identify what are the key components affecting effectiveness of SCS, highlighting their benefits, flaws and improvement opportunities.

Design/methodology/approach

An integrated literature review was conducted to identify and assess recent studies related to the benefits, flaws, effectiveness and improvement opportunities of SCS worldwide.

Findings

Key components affecting the effectiveness of SCS were identified (sustainability awareness; market access; management systems and productivity; social, environmental and economic impacts; monitoring outcomes; competition, overlapping and interoperability; stakeholder participation; and accountability and transparency). The authors argue that SCS to succeed have to be effective; provide accountability about their goals and achievements; and manage stakeholders’ expectations. Civil Society’s awareness of the scientific underpinnings of sustainability issues also contributes to the existence and improvement of such schemes.

Research limitations/implications

The limitations of this study are associated with the secondary material that was publicly available for our literature review.

Originality/value

This paper fulfils an identified need to explore the key components affecting effectiveness of SCS, their benefits, flaws and improvement opportunities. Such a synthesis also identifies the key areas where interoperability between SCS should be pursued by corporations and governments.
A framework for board capital
Authors: Pérez-Calero Leticia , Villegas Ma del Mar , Barroso Carmen
Published: June 2016

Purpose

The purpose of this paper is to examine in greater depth the concept of “board capital”, which the authors consider to be a bundle of three types of capital, and believe to be a clear antecedent of the board’s ability to perform its roles, which have positive consequences for the firm’s performance.

Design/methodology/approach

Through 83 firms listed on The Madrid Stock Exchange during the period 2005-2010, the authors test empirically the relationships between different dimensions of board capital and firm performance, and specially how internal social capital moderates the relationships between board human capital and external social capital with firm performance.

Findings

The results show that certain characteristics of human capital (average board tenure) and external social capital (directors’ interlocks) are positively related to the firm performance. The empirical findings also indicate that the internal social capital, measured by board density, is positively related to the firm performance and moderates these above relationships, increasing the potential of the resources contributed by the board members and influencing to a large extent on a firm’s performance.

Practical implications

The results of the investigation will help both executives and scholar in two ways. First, they will assist firms when they have to select board members, as they can now understand how the resources that board members bring with them can affect the firm performance. To be more effective, boards need to have members that have experience as firm’s directors, external connections to other boards and many internal ties among them. Second, in this context, internal social capital is especially relevant, so the firms should look for possible ways of encouraging internal ties between directors. In this paper, the authors have opted for study the participation of directors in committees.

Originality/value

The authors propose that these three types of capital (human, external and internal social capital) need to be synergistically combined to create a group of directors with access to a complete set of skills, knowledge and connections, but which can still work as a compact social group when making decisions.
Human mesenchymal stem cells attenuate pulmonary hypertension induced by prenatal lipopolysaccharide treatment in rats
Authors: Chou Hsiu‐Chu , Lin Willie , Chen Chung‐Ming
Published: June 2016

Intra‐amniotic injection of lipopolysaccharide (LPS) induces pulmonary hypertension in newborn rats. This study was designed to test whether human mesenchymal stem cells (MSCs) reduce pulmonary hypertension and alleviate cardiac hypertrophy in prenatal LPS‐treated rats. Pregnant Sprague‐Dawley rats were injected intraperitoneally with LPS (0.5 mg/kg per day) or untreated on gestational days 20 and 21. Human MSCs (3×105 cells and 1×106 cells) in 0.03 mL of normal saline (NS) were transplanted intratracheally on postnatal day 5. Four study groups were considered: normal, LPS+NS, LPS+MSCs (3×105 cells), and LPS+MSCs (1×106 cells). On postnatal day 14, lung and heart tissues were collected for measuring the arterial medial wall thickness (MWT) and β‐myosin heavy chain (β‐MHC) level as markers of pulmonary hypertension and cardiac hypertrophy, respectively. The LPS+NS group exhibited a significantly higher right ventricle (RV)/[left ventricle (LV)+ interventricular septum (IVS)] thickness ratio and MWT, a greater cardiomyocyte width, a greater number of cardiomyocyte nuclei per squared millimeter, and higher β‐MHC expression than those observed in the normal group. Human MSC transplantation (3×105 cells and 1×106 cells) in LPS‐treated rats reduced MWT and the RV/(LV+IVS) thickness ratio to normal levels. This improvement in right ventricular hypertrophy was accompanied by a decrease in toll‐like receptor 4 (TLR4), nuclear factor‐κB, and tumor necrosis factor‐α expression in the heart. Intratracheal human MSCs transplantation can attenuate pulmonary hypertension and right ventricular hypertrophy in prenatal LPS‐treated rats; this attenuation may be associated with suppression of TLR4 expression via paracrine pathways.