bluuebunny/crossref_metadata_2025 huggingface dataset:
Dense neuronal reconstruction through X-ray holographic nano-tomography
Authors: Pacureanu Alexandra , Maniates-Selvin Jasper , Kuan Aaron T. , Thomas Logan A. , Chen Chiao-Lin , Cloetens Peter , Lee Wei-Chung Allen
Published: May 2019

Elucidating the structure of neuronal networks provides a foundation for understanding how the nervous system processes information to generate behavior. Despite technological breakthroughs in visible light and electron microscopy, imaging dense nanometer-scale neuronal structures over millimeter-scale tissue volumes remains a challenge. Here, we demonstrate that X-ray holographic nano-tomography is capable of imaging large tissue volumes with sufficient resolution to disentangle dense neuronal circuitry in Drosophila melanogaster and mammalian central and peripheral nervous tissue. Furthermore, we show that automatic segmentation using convolutional neural networks enables rapid extraction of neuronal morphologies from these volumetric datasets. The technique we present allows rapid data collection and analysis of multiple specimens, and can be used correlatively with light microscopy and electron microscopy on the same samples. Thus, X-ray holographic nano-tomography provides a new avenue for discoveries in neuroscience and life sciences in general.
Haptic metameric textures
Authors: Kuroki Scinob , Sawayama Masataka , Nishida Shin’ya
Published: May 2019

Humans sense spatial patterns through their eyes and hands. Past studies have revealed differences (as well as similarities) between vison and touch in texture processing (e.g., eye is good at detecting texture boundaries, while hand can discriminate subtle texture differences), but the underlying computational differences remains poorly understood. Here we transcribed various textures as surface relief patterns by 3D-printing, and analyzed the tactile discrimination performance regarding the sensitivity to image statistics. The results suggest that touch is sensitive to texture differences in lower-order statistics (e.g., statistics of local amplitude spectrum), while may not to those in the higher-order statistics (e.g., joint statistics of local orientations). In agreement with this, we found that pairs of synthesized textures differing only in higher-order statistics were nearly indiscriminable (metameric) by touch, while easily discriminable by vision. Our findings show that touch and vision sense spatial information using different and complementary computational strategies.
Endocardial differentiation in zebrafish occurs during early somitogenesis and is dependent on BMP andetv2signalling
Authors: Capon Samuel J , Smith Kelly A
Published: May 2019

Abstract

The endocardium and adjacent vascular endothelial network share a number of molecular markers however there are distinct physiological functions of these tissues. What distinguishes these lineages on a molecular level remains an important, unanswered question in cardiovascular biology. We have identified theGt(SAGFF27C); Tg(4xUAS:egfp)line as a marker of early endocardial development and used this line to examine endocardial differentiation. Our results show that the endocardium emerges from the anterior lateral plate mesoderm at the 8-somite stage (13 hpf). Analysis in a number of loss-of-function models showed that whilstnkx2.5,hand2andtal1loss-of-function have no effect on the endocardial progenitor domain, bothetv2loss-of-function and inhibition of BMP signalling reduce the endocardial domain. Furthermore, manipulating BMP signalling altersetv2expression. Together, these results describe the onset of endocardial molecular identity and suggest a signalling cascade whereby BMP signalling acts upstream ofetv2to direct differentiation of endocardial progenitors.
DiADeM: differential analysis via dependency modelling of chromatin interactions with robust generalized linear models
Authors: Zaborowski Rafał , Wilczyński Bartek
Published: May 2019

High throughput Chromosome Conformation Capture experiments have become the standard technique to assess the structure and dynamics of chromosomes in living cells. As any other sufficiently advanced biochemical technique, Hi-C datasets are complex and contain multiple documented biases, with the main ones being the non-uniform read coverage and the decay of contact coverage with genomic distance. Both of these effects have been studied and there are published methods that are able to normalize different Hi-C data to mitigate these biases to some extent. It is crucial that this is done properly, or otherwise the results of any comparative analysis of two or more Hi-C experiments are bound to be biased. In this paper we study both mentioned biases present in the Hi-C data and show that normalization techniques aimed at alleviating the coverage bias are at the same time exacerbating the problems with contact decay bias. We also postulate that it is possible to use generalized linear models to directly compare non-normalized data an that it is giving better results in identification of differential contacts between Hi-C matrices than using the normalized data.
The development of cooperative channels explains the maturation of hair cell’s mechanotransduction
Authors: Gianoli Francesco , Risler Thomas , Kozlov Andrei S.
Published: May 2019

Hearing relies on the conversion of mechanical stimuli into electrical signals. In vertebrates, this process of mechano-electrical transduction (MET) is performed by specialized receptors of the inner ear, the hair cells. Each hair cell is crowned by a hair bundle, a cluster of microvilli that pivot in response to sound vibrations, causing the opening and closing of mechanosensitive ion channels. Mechanical forces are projected onto the channels by molecular springs called tip links. Each tip link is thought to connect to a small number of MET channels that gate cooperatively and operate as a single transduction unit. Pushing the hair bundle in the excitatory direction opens the channels, after which they rapidly reclose in a process called fast adaptation. It has been experimentally observed that the hair cell’s biophysical properties mature gradually during postnatal development: the maximal transduction current increases, sensitivity sharpens, transduction occurs at smaller hair-bundle displacements, and adaptation becomes faster. Similar observations have been reported during tip-link regeneration after acoustic damage. Moreover, when measured at intermediate developmental stages, the kinetics of fast adaptation varies in a given cell depending on the magnitude of the imposed displacement. The mechanisms underlying these seemingly disparate observations have so far remained elusive. Here, we show that these phenomena can all be explained by the progressive addition of MET channels of constant properties, which populate the hair bundle first as isolated entities, then progressively as clusters of more sensitive, cooperative MET channels. As the proposed mechanism relies on the difference in biophysical properties between isolated and clustered channels, this work highlights the importance of cooperative interactions between mechanosensitive ion channels for hearing.

SIGNIFICANCE

Hair cells are the sensory receptors of the inner ear that convert mechanical stimuli into electrical signals transmitted to the brain. Sensitivity to mechanical stimuli and the kinetics of mechanotransduction currents change during hair-cell development. The same trend, albeit on a shorter timescale, is also observed during hair-cell recovery from acoustic trauma. Furthermore, the current kinetics in a given hair cell depends on the stimulus magnitude, and the degree of that dependence varies with development. These phenomena have so far remained unexplained. Here, we show that they can all be reproduced using a single unifying mechanism: the progressive formation of channel pairs, in which individual channels interact through the lipid bilayer and gate cooperatively.
Neurogenin regulates effectors of migratory neuron cell behaviors in Ciona
Authors: Gibboney Susanne , Kim Kwantae , Razy-Krajka Florian , Wang Wei , Stolfi Alberto
Published: May 2019

The bipolar tail neurons (BTNs) of Ciona develop according to a highly dynamic, yet highly stereotyped developmental program and thus could serve as an accessible model system for neuronal delamination, migration, and polarized axon outgrowth. Here we used FACS/RNAseq to profile the transcriptional output of Neurogenin in the BTNs, searching for candidate effectors of BTN cell behaviors. We identified several candidate genes that might play conserved roles in similar cell behaviors in other animals, including mammals. Among the more interesting candidates were several microtubule-binding proteins and TGFβ pathway antagonists. A small Gαi subunit was also found to be upregulated in migrating BTNs, and interfering with its function through expression of a dominant negative inhibited delamination and a complete epithelial-to-mesenchymal transition. We propose models for the regulation of BTN behaviors by the identified candidate effectors, establishing a foundation for testing effector gene functions that might be conserved in chordate neurodevelopment.
Phosphorylation by CK2 increases the SUMO-dependent activity of Cytomegalovirus transactivator IE2
Authors: Tripathi Vasvi , Chatterjee Kiran Sankar , Das Ranabir
Published: May 2019

Viral factors manipulate the host post-translational modification (PTM) machinery for replication. Distinctly, phosphorylation and SUMOylation can regulate the activity of human cytomegalovirus (HCMV) protein IE2. However, the molecular mechanism of this process is unknown. Taking a structural, biochemical and cellular approach, we uncover a cross-talk of phosphorylation and SUMOylation exploited by IE2. A scan for the SUMO Interacting Motifs (SIMs) revealed two SIMs in IE2. A real-time SUMOylation assay indicated that the N-terminal SIM (IE2-SIM1) enhanced IE2 SUMOylation up to 4-fold. Kinetic analysis and structural studies proved that IE2 is a SUMO cis-E3 ligase. Two putative CK2 sites adjacent to IE2-SIM1 are phosphorylated in-vitro and in cellular conditions. Phosphorylation drastically increased the IE2/SUMO affinity, IE2-SUMOylation and cis-E3 activity of IE2. Additional salt-bridges between the phosphoserines and SUMO account for the higher IE2/SUMO affinity. Phosphorylation also enhances the SUMO-dependent transactivation activity and auto-repression activity of IE2. Together, our findings highlight a novel mechanism where SUMOylation and phosphorylation of the viral cis-E3 ligase and transactivator protein IE2, works in tandem to enable transcriptional regulation of viral genes.

Author summary

The host protein SUMO is a crucial regulator of cellular processes. Conjugation of other proteins to SUMO by a process called SUMOylation, can change the protein’s function or localization and regulate downstream cellular events. The SUMO pathway is exploited by viruses to transcribe viral genes and replicate the viral genome. IE2 is an essential gene of human Cytomegalovirus (HCMV), which acts as a transactivator and helps to transcribe other viral proteins required for viral genome replication and viral assembly. SUMOylation of IE2 is necessary for its function. Here, we have uncovered that IE2 functions as a cis-SUMO-E3 ligase, where a SUMO-Interacting Motif (SIM) in IE2 enhances its SUMOylation. Interestingly, phosphorylation of the SIM in IE2 augments its cis-E3 activity to further increase SUMOylation. Moreover, SIM phosphorylation also enhances the interaction between IE2 and SUMOylated binding partners. Thus, we uncover an exciting process, where phosphorylation enhances both covalent and non-covalent interaction of a protein (IE2) and SUMO. We also observe that the cross-talk of phosphorylation and SUMOylation has significant effects on the transactivation function of IE2. Overall, we discover how a viral protein IE2 exploits crosstalk between SUMOylation and Phosphorylation to enhance its activity and in turn, ensure efficient viral replication.
The effect of alien species on plant-pollinator network structure across a gradient of plant species invasion
Authors: Parra-Tabla Víctor , Angulo-Pérez Diego , Albor Cristopher , Campos-Navarrete María José , Tun-Garrido Juan , Sosenski Paula , Alonso Conchita , Ashman Tia-Lynn , Arceo-Gómez Gerardo
Published: May 2019

The interactions between pairs of native and alien plants via shared use of pollinators have been widely studied. Studies of invasive species effects at the community level on the other hand are still scarce. Few community level studies, however, have considered how differences in the intensity of invasion, and degree of floral trait similarity between native and invasive species, can mediated effects on native plant-pollinator communities. Here, we evaluated the effect of alien species on overall plant-pollinator network structure, and species-level network parameters, across nine coastal communities distributed along 205 km at Yucatán, México that vary in alien species richness and flower abundance. We further assessed the effect of alien plant species on plant-pollinator network structure and robustness via computational simulation of native and invasive plant extinction scenarios. We did not find significant differences between native and alien species in functional floral phenotypes, the visitation rate and species composition of the pollinator community. Variation in the proportion of alien plant species and flower abundance across sites did not affect plant-pollinator networks structure. Species-level network parameters (i.e., normalized degree and nestedness contribution) did not differ between native and alien species. Furthermore, our simulation analyses revealed that alien species are functionally equivalent to native species and contribute equally to network structure and robustness. Overall, our results suggest that alien species are well integrated into native coastal plant-pollinator networks which may be facilitated by high levels of floral trait similarity and pollinator use overlap. As a result, alien species may play a similar role than that of natives in the structure and stability of native plant and pollinator communities in the studied coastal sand dune ecosystem.
Safety assessment of a novel C-type natriuretic peptide derivative and the mechanism of bone- and cartilage-specific toxicity
Authors: Yotsumoto Takafumi , Morozumi Naomi , Nakamura Ryuichi , Jindo Toshimasa , Furuya Mayumi , Abe Yasuyuki , Nishimura Tomonari , Maeda Hiroaki , Ogasawara Hiroyuki , Minamitake Yoshiharu , Kangawa Kenji
Published: May 2019

ASB20123, a C-type natriuretic peptide/ghrelin chimeric peptide, was designed as a novel peptide and demonstrated full agonistic activity for natriuretic-peptide receptor B and a significantly longer half-life in plasma compared with the native peptide. We researched the toxicological profile of ASB20123, the correlation between the morphological change of the epiphyseal plate and bone and cartilage toxicity, and biomarkers to detect the toxicity. ASB20123 was systemically administered to male and female rats at daily dose levels of 0.5, 1.5, and 5.0 mg/kg/day for 4 weeks. In this study, toxicity was observed as changes related to bone and cartilage tissues, and no other toxicological changes were observed in all animals. Next, ASB20123 was administered to 12-month-old rats with a little epiphyseal plate. The toxic changes related to bone and cartilage tissues were not observed in any animal with a closed epiphyseal plate, indicating that the toxic changes were triggered by the growth-accelerating effect on the bone and cartilage. Furthermore, we searched for the biomarker related to the bone and cartilage toxicity using rats treated with ASB20123 at doses of 0.005, 0.05, 0.5, and 5.0 mg/kg/day for 4 weeks. A close correlation between necrosis/fibrosis in the epiphysis and metaphysis and thickness of the epiphyseal plate in the femur was confirmed in this study. A decrease in the bone mineral density (BMD) of the femur also was associated with the appearance of bone toxicity. These results indicated that the toxicity of ASB20123 was limited to bone- and cartilage-specific changes, and these changes were triggered by an excessive growth accelerating effect. Furthermore, our data suggested that the thickness of the epiphyseal plate and BMD could be reliable biomarkers to predict bone toxicity.
The subtle balance of insulin and thyroxine on survival and development of primordial follicles culturedin vitroenclosed in ovarian tissue
Authors: Paes Victor M. , Lima Laritza F. , Ferreira Anna-Clara A. , Lobo Carlos H. , Alves Benner G. , Rodrigues Ana-Paula R. , Oliveira Ariclecio C. , Figueiredo Jose R. , Feugang Jean M.
Published: May 2019

Thyroid hormones have presented a positive hormonal interaction on follicular development of secondary follicles and oocytes from antral follicles; however, the effect of thyroid hormones on primordial follicles is unclear. Here we investigated thein vitroeffects of combined insulin and thyroxine on caprine primordial follicle survival and development. Ovarian tissues were cultured for 1 or 7 days using 10 ng/ml (low) or 10 µg/ml (high) insulin in the absence or presence of thyroxine at 0.5, 1 or 2 µg/ml. Thereafter, follicular survival and development, gene expression related to apoptosis (Bcl2/Bax), insulin and thyroid receptors, and estradiol and reactive oxygen species production were evaluated. In low-insulin conditions, supplementation with 2 µg/ml thyroxine maintained follicular survival similar to non-cultured control, while 0.5 µg/ml thyroxine enhanced the survival (P<0.05) in comparison to thyroxine-free treatment. Only treatments containing low-insulin and thyroxine at 0.5 or 2 µg/ml increased (P<0.05) reactive oxygen species production from day 1 to day 7. Contrarily to high-insulin containing medium, the presence of thyroxine in low-insulin medium yielded higher stromal cell density (P<0.05). There were higher (P<0.05) estradiol production andBcl2/Baxratio in low-insulin versus high-insulin treatments on day 1 and 7, respectively. High levels of both insulin and thyroxine showed better follicular development (P<0.05), yielding great follicle and oocyte diameter. Finally, the high-insulin level led to insulin and thyroid receptors expression reduction as compared to non-cultured control. In conclusion, the combination of low concentrations of insulin and thyroxine better maintained follicle survival, while high levels ensured better follicular development.
Accounting and professional work in established NPM settings
Authors: Sjögren Ebba , Fernler Karin
Published: May 2019

Purpose

The paper problematizes previous research on accountingisation, where the role of accounting in determining the scope of professional work is understood in relation to a professional/economic dichotomy and a model of episodic change. The purpose of this paper is to investigate everyday professional work in established new public management (NPM) settings, and proposes a new conceptual framework to analyze the role of accounting therein. The aim is to enable future investigations into how, when and where a situated “bottom line” emerges, by conceptualizing professional work as a process of calculation.

Design/methodology/approach

Qualitative data from case studies of two tertiary level geriatric organizations using observations of 33 employees and four interviews. Data related to patient discharge, and the management of the discharge processes, were analyzed.

Findings

Few visible trade-offs between distinctly professional or economic considerations were observed. Rather, the qualification of patients’ status and evaluation of their dischargeability centered on debates over treatment time. Time therefore operated as a situated “bottom line,” to which various other concerns were emergently linked in a process of calculation. Professional practitioners seldom explicitly evoke accounting concepts and technologies, but these were implicated in the ongoing translation of each patient into something temporarily stable, calculable and thus actionable for the professionals involved in their care. The study’s findings have implications for the conceptual understanding of professional work in established NPM settings.

Research limitations/implications

Case study research is context-specific and the role of accounting in professional work will vary due to the professional groups and accounting technologies involved.

Practical implications

The study’s findings have implications for how to influence professional behavior through interventions in the existing landscape of accounting technologies. The possibility to change behavior through the introduction or removal of individual accounting technologies is questioned.

Originality/value

To date, research on the role of accounting in determining the scope of professional work has assumed a professional/economic dichotomy and studied episodic change linked to accounting-oriented reforms. This paper analyses the role of accounting as an on-going process with emergent boundaries between professional and economic considerations.
Determinants of adoption of International Financial Reporting Standards in Ugandan micro finance institutions
Authors: Bananuka Juma , Tumwebaze Zainabu , Musimenta Doreen , Nuwagaba Patience
Published: May 2019

Purpose

The purpose of this paper is to report on the results of a study carried out to establish the contribution of board of directors’ effectiveness, intellectual capital (IC) and managerial attitude to the adoption of International Financial Reporting Standards (IFRSs) in microfinance institutions (MFIs).

Design/methodology/approach

This study is cross-sectional and correlational. Data were collected through a questionnaire survey of 67 MFIs that are members of the Association of Microfinance Institutions of Uganda. The data were analyzed using statistical package for social sciences.

Findings

Both board of director’s effectiveness and IC positively and significantly contribute to the adoption of IFRSs. Managerial attitude is positively and significantly associated with the adoption of IFRSs, but its explanatory power is subsumed in IC.

Originality/value

To the authors’ knowledge, this is the first study to investigate the contribution of board of director’s effectiveness, IC and managerial attitude to the adoption of IFRSs in MFIs using evidence from a developing African country like Uganda.
Development and validation of an organisational commitment instrument for generation Y employees in small and medium-sized enterprises in Thailand
Authors: Na-nan Khahan , Saribut Salitta
Published: May 2019

Purpose

Organisational commitment (OC) has become a hot behavioural topic among researchers, scholars and consulting firms. However, OC instruments have rarely been studied and developed by academics in small and medium-sized Thai enterprises (SMEs). The purpose of this paper is to develop an instrument to measure the OC of Generation Y employees in Thai SMEs.

Design/methodology/approach

A measurement scale for OC was established in three stages. First, 16 questions were developed as a questionnaire based on the concepts and theories of OC, and a survey was conducted for 360 Generation Y employees working in various SMEs. Second, the questions were validated using exploratory factor analysis and, finally, confirmatory factor analysis and convergent validity were tested.

Findings

The OC instrument presented excellent reliability at 0.865. Three factors of the 16 questions as normative commitment, affective commitment and continuance commitment were extracted. These all passed the general rule of thumb for minimum acceptability of a measurement system.

Originality/value

This OC instrument has concrete psychometric measurements and can be applied by researchers, scholars, practitioners and organisations in other settings, especially in the Thai context. Importantly, factor analysis results suggested that the OC questionnaire was suitable for utilisation and application as is, or with minimal modifications, to various business fields and/or settings.
An investigation of stimuli-current thresholds on the non-steady contact condition
Authors: Chen Huiling , Shuai Liguo , Zhu Weihang , Miao Mei
Published: May 2019

Purpose

This paper aims to investigate the perception threshold (PT) of electrotactile stimulation under non-steady contact condition (NSCC) which is rarely considered in previous reports mainly because of the difficulty with experimental control. Three factors of NSCC are involved, including the current alternating frequency, the tapping interval of stimulation and the stimulating area of skin. The study is aimed at providing the basic PT data for design and application of wearable and portable electrotactile device.

Design/methodology/approach

The up-down method was selected to assess PT, and 72 experimental scenarios were constructed. During the study, we developed an experimental platform with the function of data record and programmable current stimulation. With psychophysical experiment, more than 10,000 data were collected. Furthermore, statics analysis and ANOVA test were opted for exploring the main factor influencing PT.

Findings

NSCC has different PTs on each body location, and PT has a positive correlation with frequency. In general, PT in NSCC is significantly lower than that in SCC. In some cases, it can be lower by more than 60 per cent. In addition, women have a lower PT than men across all age groups, and the younger is generally more sensitive than the older in electro-sensation.

Research limitations/implications

Limited factors of NSCC were considered in this study. Contact time and break interval should be investigated in the future work.

Practical implications

The paper includes implications for the development of smart electrotactile device.

Originality/value

This paper fulfills a challenge in assessing the PT under NSCC.
Matching serious games with museum’s educational roles: smart education in practice
Authors: Wang Meng , Nunes Miguel Baptista
Published: May 2019

Purpose

This study aims to present a meta-analysis of the use of serious educational games in museums. The analysis is based on a critical literature review that maps educational roles of museums against serious educational games used in support of those roles. The meta-analysis focuses on the specific context of informal learning in museums.

Design/methodology/approach

The research design presented in this study is based on a meta-analysis research design that consists of a critical literature review, a multi-matrix representation of findings of the literature review and a conceptual visualization of the multidisciplinary area of the usage of serious games in support of educational roles in museums.

Findings

Clear and detailed categorizations of educational roles and serious games types for informal learning are presented. These are followed by matching these educational roles with published reports of the use of serious games within museums. The study concludes with observations and a conceptual map of the design of serious games for museums.

Originality/value

This study presents the first meta-analysis of research in this emergent multidisciplinary field. It will help serious game designers, museum educators and educational practitioners to make decisions regarding the choice of game type, customization and content design to support informal learning in the specific context of museum educational activities.
Communicating environmental sustainability initiatives virtually
Authors: Hopkins Erin
Published: May 2019

Purpose

The purpose of this paper is to uncover the extent to which firms in the apartment property management industry in the USA are promoting green property management services via communication on their websites.

Design/methodology/approach

A content analysis is the main research method for this study. Once all qualifying terms listed on the company website were recorded based on LEED credit and category, the data were synthesized to create a sustainability continuum organizing the firms based on the extent to which they communicate sustainability initiatives on their respective websites.

Findings

The results demonstrate that the majority of the largest 50 apartment management firms in the USA are not communicating any sustainability initiatives on their website. In all, 52 percent of companies have no acknowledgment of sustainability initiatives on their website; 16 percent of companies provide some cursory reference to sustainability initiatives; 16 percent offer some detail on their website; 6 percent contain in-depth detail plus metrics. The remaining 10 percent of firms are providing comprehensive sustainability reporting on their websites.

Practical implications

Property management companies have an immense opportunity to capitalize on showcasing their green building features via company websites. Not only does incorporating environmental sustainability practices support a climate mitigation strategy, marketing these practices can foster consumer satisfaction and a willingness to pay more. With the awareness that opportunity abounds both to mitigate negative environmental externalities and complement financial goals of apartment property management companies, this research sheds light for property management companies and related parties of missed opportunities in the environmental sustainability space.

Originality/value

The analysis presented in this paper is one of the first to the author’s knowledge to explore the degree which property management companies are promoting green real estate management services through website communication.
Medical tourism: tourists’ perceived services and satisfaction lessons from Malaysian hospitals
Authors: Rahman Muhammad Khalilur
Published: May 2019

Purpose

The medical tourism industry has become one of the most profitable industries around the world wherein most of the countries exploit every effort to attract medical tourists to take advantage of its medical care benefits. The purpose of this study is to explore the determinants of medical tourists’ perceived services and their satisfaction for medical care in hospitals.

Design/methodology/approach

The quantitative method was conducted to examine the three groups of foreign travellers such as medical tourists, expats and normative medial tourists’ perceived medical services quality and satisfaction. Data from a survey of 266 respondents were analyzed using the structural equation modelling technique.

Findings

The findings of this study provide evidence that hospital accessibility and interpersonal behaviour are the most critical constructs that influence medical tourists’ attributes. Additionally, medical costs and health-care technicality have a significant relationship with the perceived services of medical tourists. The study also demonstrated that medical tourists’ satisfaction highly attributed to their perceived services towards the quality of medical care they received and experienced in the hospitals.

Practical implications

The results have important implications for managerial considerations at hospitals. Hospital accessibility is a crucial dimension to be measured at hospitals when measuring service quality. Service providers need to be mindful that all aspects of medical services are essential and need to be delivered satisfactorily to ensure customer satisfaction. Patients’ perceived services and their satisfaction is a crucial bridge in determining the likelihood of future return among patients to the hospitals.

Originality/value

This study has managed to convincingly secure findings to provide useful information and understanding of the hospital accessibility and interpersonal manner of health-care professionals at hospitals in Malaysia. Particularly, when any hospital offers quality services, they must consider the reasonable medical expenses that can be affordable by the average people and update their medical equipment that are necessary for technical and diagnostic purposes. By ensuring these, they can attract the medical tourists.
Parametric optimization-based design of PI controllers: application to a DC servomechanism
Authors: Tabatabaei Mohammad
Published: May 2019

Purpose

This paper aims to propose an analytical method for designing parametric optimization-based proportional integral (PI) controllers.

Design/methodology/approach

In this method, a performance index containing the weighted summation of the integral square of the error and its derivative is minimized. This performance index is analytically calculated in terms of the controller parameters by solving a Lyapunov equation. Then partial derivatives of the performance index with respect to controller parameters are calculated. Equating these partial derivatives to zero gives explicit relations for the PI controller parameters.

Findings

The experimental tests on a DC servomotor system are given to demonstrate the efficiency of the proposed method.

Originality/value

This paper proposes an analytical parametric optimization approach for designing PI controllers for the first time. The application of the proposed method in a laboratory experiment is examined.
Experimental investigation and optimization of a low-temperature thermoelectric module with different operating conditions
Authors: Patil Dipak Sudam , Arakerimath Rachayya R. , Walke Pramod V.
Published: May 2019

Purpose

This paper aims to present an experimental investigation and optimization of a low-temperature thermoelectric module to examine the influence of the main operating conditions.

Design/methodology/approach

In this work, a comparison was made by varying the various operating parameters such as heat source temperature, the flow rate of the cold fluid and the external load resistance. A Taguchi method was applied to optimize the parameters of the system. Three factors, including the external load resistance, mass flow rate of water (at the heat sink side) and heater temperature (at the heat source side) along with different levels were taken into account. Analysis of variance was used to determine the significance and percentage contribution of each parameter.

Findings

The experimental results show that the maximum power output 8.22W and the maximum conversion efficiency 1.11 per cent were obtained at the heater temperature of 240°C, the cold fluid mass flow rate of 0.017 kg/s, module temperature difference of 45°C and the load resistance of 5 O. It was observed that the optimum parameter levels for maximum power output determined as 5 O external load resistance, 0.17 kg/s mass flow rate of water and 240°C heater temperature (A1B3C3). It reflects that these parameters influence on the optimum conditions. The heater temperature is the most significant parameter on the power output of the thermoelectric module.

Originality/value

It is clear from the confirmation test that experimental values and the predicted values are in good agreement.
Effect of average beam power on microstructure and mechanical properties of Nd: YAG laser welding of 304L and st37 steel
Authors: Kumar Pramod , Sinha Amar Nath
Published: May 2019

Purpose

The present research work aims to study the effect of average beam power (laser process parameters) on the overlapping factor, depth of penetration (DOP), weld bead width, fusion zone and heat affected zone (HAZ) in laser welding of 304L and st37 steel. Back side and top surface morphology of the welded joints have also been studied for varying average beam power.

Design/methodology/approach

Laser welding of austenitic stainless steel (304L) and carbon steel (st37) was carried out using Nd:YAG laser integrated with ABB IRB 1410 robot in pulse mode. The selection of laser process parameters was based on the specification of available laser welding machine. Dissimilar laser welding of 304L and st37 carbon steel for full depth of penetration have been performed, with varying average beam power (225-510W) and constant welding speed (5mm/s) and pulse width (5ms).

Findings

Recrystallized coarse grains were observed adjacent to the fusion zone and nucleated grains were seen away from the fusion zone towards carbon steel. Overlapping factor and HAZ width st37 side increases with increase in average beam power whereas top weld bead width increases first, attains maximum value and then subsequently decreases. Bottom weld bead width increases with increase in average beam power. The mechanical properties namely microhardness and tensile strength of the welded joints have been investigated with varying average beam power.

Originality/value

In the recent development of the automobile, power generation and petrochemical industries the application of dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) are gaining importance. Very limited work have been reported in pulsed Nd:YAG dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) for investigating the effect of laser process parameters on weld bead geometry, microstructural characterization and mechanical properties of the welded joint.
Frequent chloroplast capture among Isodon (Lamiaceae) species in Japan revealed by phylogenies based on variation in chloroplast and nuclear DNA
Authors: Ogishima Miho , Horie Sachikio , Kimura Takuma , Yamashiro Tadashi , Dohzono Ikumi , Kawaguchi Lina , Nagano Atsushi J. , Maki Masayuki
Published: May 2019

A recent phylogenetic study based only on chloroplast DNA (cpDNA) variation revealed that populations of an Isodon species are frequently embedded paraphyletically among other Isodon species. This phylogenetic discrepancy between species taxonomy and molecular phylogeny was considered to have resulted from chloroplast DNA captures and/or incomplete lineage sorting. To elucidate which of these factors was mainly responsible for the observed phylogenetic pattern, we performed phylogenetic analyses of multiple populations of Isodon species in Japan using cpDNA variation, three single‐copy nuclear genes, and double‐digest restriction‐site‐associated DNA sequencing (ddRAD‐seq). Although a species often shared chlorotypes with other species, our phylogenetical analyses based on variation in the three single‐copy nuclear genes and the ddRAD‐seq data showed that most populations belonging to the same species were monophyletic at the species level, suggesting that chloroplast capture may have frequently occurred between Isodon species. Some populations of an intraspecific taxon were embedded paraphyletically within the species, regardless of the large amount of phylogenetic information in nuclear DNA; this incongruity may have resulted from incomplete lineage sorting.
The use of buttermilk as a raw material for cheese production
Authors: Skryplonek Katarzyna , Dmytrów Izabela , Mituniewicz‐Małek Anna
Published: May 2019

Buttermilk is dairy by‐product of butter production. The study aimed to analyse the quality properties of commercial buttermilk and its usefulness as a raw material for Quark cheese production. Within the study, 6 kinds of buttermilk were tested and used for cheese production. Evaluation of cheese quality included physico‐chemical, rheological and sensory analyses. Buttermilk properties were varied and corresponded with the diversification of cheese characteristics. Production yield was 17.2–22.7%, water content 68.1–75.8% and pH 4.09–4.43. The texture was diversified; however, all samples had good sensory quality. The research has shown that buttermilk is a good raw material for cheese production.
The Maastrichtian‐Danian in the SW Zagros Fold‐Thrust Belt (S. Iran): An Integration of Planktonic Foraminiferal Biostratigraphy and Gamma‐Ray Spectrometry
Authors: MOGHADDASI Abdolreza , VAZIRI‐MOGHADDAM Hossein , SEYRAFIAN Ali
Published: May 2019

In this study, the Maastrichtian‐Danian boundary was measured and sampled in two stratigraphic sections, the north and south flanks of the Dehnow anticline in Coastal Fars, Southern Iran. This boundary was also investigated in the drilled exploratory well‐1 in the same region. The lithology of the Maastrichtian‐Danian deposits consists of glauconitic, phosphatic argillaceous limestones and marlstones. 30 genera and 77 species of planktonic foraminifera have been determined. The recognized biozones are theGansserina gansseriInterval Zone, and theContusotruncana contusaInterval Zone, which indicates latest Campanian to middle Maastrichtian age for the upper part of the Gurpi Formation. In addition, theEoglobigerina edita(P1) Partial Range Zone,Praemurica uncinata(P2) Lowest Occurrence Zone,Morozovella angulata(P3) Lowest Occurrence Zone andGlobanomalina psudomenardii(P4) Taxon Range Zone represent a Danian to Thanetian age for the lower part of the Pabdeh Formation. From the absence of theAbathomphalus mayaroensisInterval Zone,Pseudoguembelina hariaensisInterval Zone,Pseudotextularia elegansInterval Zone,Plummerita hantkeninoidesInterval Zone,Guembelitria cretacea(P0) Partial Range Zone andParvularugoglobigerina eugubina(Pα) Total Range Zone, it can be deduced that there is a paraconformity across the Maastrichtian–Danian boundary in the studied area, this hiatus encompassing the late Maastrichtian and the earliest Danian. Danian deposits from the study area contain reworked glauconitized macrofossils, planktonic and benthic foraminifera of the Cretaceous. The obtained surface gamma‐ray spectrometry logs resemble the exploratory well‐1 gamma‐ray wireline log.
Hydrogeochemical Characteristics and Groundwater Inrush Source Identification for a Multi‐aquifer System in a Coal Mine
Authors: ZHANG Haitao , XU Guangquan , CHEN Xiaoqing , WEI Jian , YU Shitao , YANG Tingting
Published: May 2019

Correct identification of water inrush sources is particularly important to prevent and control mine water disasters. Hydrochemical analysis, Fisher discriminant analysis, and geothermal verification analysis were used to identify and verify the water sources of the multi‐aquifer groundwater system in Gubei coal mine, Anhui Province, North China. Results show that hydrochemical water types of the Cenozoic top aquifer included HCO3–Na+K–Ca, HCO3–Na+K–Mg and HCO3–Na+K, and this aquifer was easily distinguishable from other aquifers because of its low concentration of Na++K+ and Cl–. The Cenozoic middle and bottom aquifers, the Permian fissure aquifer, and the Taiyuan and Ordovician limestone aquifers were mainly characterized by the Cl–Na+K and SO4–Cl‐Na+K or HCO3–Cl–Na+K water types, and their hydrogeochemistries were similar. Therefore, water sources could not be identified via hydrochemical analysis. Fisher model was established based on the hydrogeochemical characteristics, and its discrimination rate was 89.19%. Fisher discrimination results were improved by combining them with the geothermal analysis results, and this combination increased the identification rate to 97.3 % and reasonably explained the reasons behind two water samples misjudgments. The methods described herein are also applicable to other mines with similar geological and hydrogeological conditions in North China.
Cyclic Characteristics of the Physical Properties of Key Strata in CBM Systems Controlled by Sequence Stratigraphy—An Example from the Gujiao Block
Authors: WANG Gang , QIN Yong , XIE Yiwei , WANG Ziwei , WANG Boyang , WANG Qi , ZHANG Xiaoyang
Published: May 2019

Multiple coal seams and interbedded rock assemblages formed in vertical progression due to the influence of multiple stages of sea level transgressions. Based on mercury injection experiment, low temperature liquid nitrogen experiment, porosity and permeability experiment and breakthrough pressure experiment, the vertical variation characteristics of coal‐bearing strata in Gujiao block are explained in detail. The results of the mercury injection and low temperature liquid nitrogen experiments show that the pore structure characteristics fluctuate with increasing depth in the strata, with fewer micropores followed by transition pores. The BET specific surface area and average pore diameter of the Shanxi Formation are generally larger than those of the Taiyuan Formation. Due to the continuous cyclic sequence stratigraphy changes, the porosity, permeability, breakthrough pressure and breakthrough time of the samples show a certain cyclicity. Within the same sequence, the porosity is larger, and the permeability is smaller near the maximum flooding surface. Although the permeability of the sandstone samples is higher, the porosity is lower, and the breakthrough pressure and breakthrough times are greater. The strata in the study area formed in an oxidized environment that was affected by freshwater, and the pore structure of different lithologies is quite different. After the formation of sandstone, the intergranular pores generally underwent filling with secondary quartz, clay minerals and organic matter, resulting in low porosity and permeability.
The Sensitive Properties of Hydrate Reservoirs Based on Seismic Stereoscopic Detection Technology
Authors: LIU Xueqin , XING Lei , QIN Zhiliang , LIU Huaishan
Published: May 2019

Higher‐precision determinations of hydrate reservoirs, hydrate saturation levels and storage estimations are important for guaranteeing the ability to continuously research, develop and utilize natural gas hydrate resources in China. With seismic stereoscopic detection technology, which fully combines the advantages of different seismic detection models, hydrate formation layers can be observed with multiangle, wide‐azimuth, wide‐band data with a high precision. This technique provides more reliable data for analyzing the distribution characteristics of gas hydrate reservoirs, establishing velocity models, and studying the hydrate‐sensitive properties of petrophysical parameters; these data are of great significance for the exploration and development of natural gas hydrate resources. Based on a velocity model obtained from the analysis of horizontal streamer velocity data in the hydrate‐bearing area of the Shenhu Sea, this paper uses three VCs (longitudinal spacing of 25 m) and four OBSs (transverse spacing of 200 m) to jointly detect seismic datasets consisting of wave points based on an inversion of traveltime imaging sections. Accordingly, by comparing the differences between the seismic phases in the original data and the forward‐modeled seismic phases, multiangle coverage constraint corrections are applied to the initial velocity model, and the initial model is further optimized, thereby improving the imaging quality of the streamer data. Petrophysical elastic parameters are the physical parameters that are most directly and closely related to rock formations and reservoir physical properties. Based on the optimized velocity model, the rock elastic hydrate‐sensitive parameters of the hydrate reservoirs in the study area are inverted, and the sensitivities of the petrophysical parameters to natural gas hydrates are investigated. According to an analysis of the inversion results obtained from these sensitive parameters, λρ, Vp and λμ are simultaneously controlled by the bulk modulus and shear modulus, while Vs and μρ are controlled only by the shear modulus, and the latter two parameters are less sensitive to hydrate‐bearing layers. The bulk modulus is speculated to be more sensitive than the shear modulus to hydrates. In other words, estimating the specific gravity of the shear modulus among the combined parameters can affect the results from the combined elastic parameters regarding hydrate reservoirs.
Inconsistent Signals, Earnings Announcements, and Market Uncertainty
Authors: He Wen , Jackson Andrew B. , Liang Kevin
Published: May 2019

We test the proposition in Johnstone (2016) that new information may lead to higher, rather than lower, uncertainty about firms’ future payoffs. Based on the Bayesian rule, we hypothesize earnings news that is inconsistent with investors’ prior belief will lead to higher market uncertainty. Using earnings signals in the past few quarters to proxy for investors’ prior belief, we find supporting evidence that, relative to consistent earnings news, inconsistent news results in an increase in market uncertainty measured by implied volatility. Inconsistent earnings news has a larger effect on market uncertainty when prior beliefs are stronger and when the news is negative. Overall, our evidence highlights the importance of prior belief and inconsistent signals in understanding the effect of earnings news on market uncertainty.