bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing cross-national invariance of the three-component model of organizational commitment
Authors: Nandan Shefali , Halkias Daphne , Thurman Paul W. , Komodromos Marcos , Alserhan Baker Ahmad , Adendorff Chris , Yahaya Alhaj Norashfah Hanim Yaakop , De Massis Alfredo , Galanaki Eleanna , Juma Norma , Kwesiga Eileen , Nkamnebe Anayo D. , Seaman Claire
Published: October 2019

Purpose

The purpose of this paper is to examine affective commitment, normative commitment, and continuance commitment in a cross-national context to identify if the effect of country-specific cultural orientation on organizational commitment of faculty in higher education functions invariably in different countries.

Design/methodology/approach

The work expands on Meyer and Allen’s (1991) three-component model of organizational commitment. It includes relevant literature review on ten countries and the results of a survey of university faculty members, assessing their institutions’ human resources practices and their effect on organizational commitment. Basic descriptive statistics were performed on nominal and interval data, means, medians, and standard deviations were computed, and tests of mean equivalence, including ANOVA tests, were performed. In certain instances, Pearson and Spearman correlations were computed to ascertain correlation, andχ2tests for randomized response were used, while Cronbach’sαtest helped to establish survey instrument validity.

Findings

Though certain differences may exist between different countries and cultures with respect to the three-component model of organizational commitment, there is strong evidence of the existence of invariance and, thus, generalizability of the model across cultures.

Research limitations/implications

Cultural studies have focused on differences in organizational commitment at national levels. Further attempts to identify the universality of factors leading to organizational commitment should account for culture in the study of employee-related globalization issues in higher education institutes. Knowledge of cultural impact is also useful from a managerial perspective, and for the design of relevant strategies.

Practical implications

National context plays a major role in shaping the nature of educational institutions. This study brings out the need for a deeper understanding of invariance in organizational commitment (inter-alia, through the three-component model).

Originality/value

This study contributes to a better understanding of the relationship between organizational commitment and its various antecedents, including human resources management practices, for faculty in higher education institutes.
Structural fire performance of wood-steel-wood bolted connections with and without perpendicular-to-wood grain reinforcement
Authors: Petrycki Adam Roman , Salem Osama (Sam)
Published: October 2019

Purpose

In fire condition, the time to failure of a timber connection is mainly reliant on the wood charring rate, the strength of the residual wood section, and the limiting temperature of the steel connectors involved in the connection. The purpose of this study is to experimentally investigate the effects of loaded bolt end distance, number of bolt rows, and the existence of perpendicular-to-wood grain reinforcement on the structural fire behavior of semi-rigid glued-laminated timber (glulam) beam-to-column connections that used steel bolts and concealed steel plate connectors.

Design/methodology/approach

In total, 16 beam-to-column connections, which were fabricated in wood-steel-wood bolted connection configurations, in eight large-scale sub-frame test assemblies were exposed to elevated temperatures that followed CAN/ULC-S101 standard time-temperature curve, while being subjected to monotonic loading. The beam-to-column connections of four of the eight test assemblies were reinforced perpendicular to the wood grain using self-tapping screws (STS). Fire tests were terminated upon achieving the failure criterion, which predominantly was dependent on the connection’s maximum allowed rotation.

Findings

Experimental results revealed that increasing the number of bolt rows from two to three, each of two bolts, increased the connection’s time to failure by a greater time increment than that achieved by increasing the bolt end distance from four- to five-times the bolt diameter. Also, the use of STS reinforcement increased the connection’s time to failure by greater time increments than those achieved by increasing the number of bolt rows or the bolt end distance.

Originality/value

The invaluable experimental data obtained from this study can be effectively used to provide insight and better understanding on how mass-timber glulam bolted connections can behave in fire condition. This can also help in further improving the existing design guidelines for mass-timber structures. Currently, beam-to-column wood connections are designed mainly as axially loaded connections with no guidelines available for determining the fire resistance of timber connections exerting any degree of moment-resisting capability.
Antioxidant properties and sensory attributes of blends prepared from standardized milk and soy milk
Authors: Pratap Devendra , Halder Kumaresh , Singh Rakhi , Ojha Ankur , S. Thangalakshmi , Rani Savita
Published: October 2019

Purpose

Although milk is considered a vital source of nutrition for the livelihood, as the beginning of civilization, its antioxidant potential is required to be improved. This paper aims to increase antioxidant activities in milk and soy milk (Glycine maxL.) has been found as a good compatible source. Hence, the present work was planned to investigate the impact of blending of different proportions of soy milk with standardized milk (i.e. 50 per cent soy milk with 50 per cent standardized milk, 60 per cent soy milk with 40 per cent standardized milk, 70 per cent soy milk with 30 per cent standardized milk and 100 per cent standardized milk as control sample) on antioxidant properties and sensory attributes of the blends.

Design/methodology/approach

Antioxidant properties of the blends were determined in terms of 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power and total phenol content. Sensory evaluation was carried out using a nine-point hedonic scale based on four selected quality attributes (i.e. smell, taste, color and appearance and mouthfeel) and ranked for their quality traits by fuzzy modeling.

Findings

A blend containing 70 per cent soy milk with 30 per cent standardized milk showed the highest antioxidant activities as compared to control milk sample (p < 0.05). Blend of 50 per cent soy milk with 50 per cent standardized milk was found most acceptable on the basis of sensory analysis and its antioxidant activities were also appreciable as compared to control milk sample (p < 0.05). Smell, taste, color and appearance and mouthfeel influenced the acceptability of formulated milk samples in decreasing order of significance (p < 0.05).

Originality/value

The present attempt has been made to formulate liquid milk by mixing standardized milk and soy milk, in which enhancement in the antioxidant activities of standardized milk and masking of off-flavor of soy milk is done. It is not done before and it may improve the nutritional and commercial value of the milk. Further, fuzzy modeling used for choosing appropriate blend in terms of sensory scores is also found as a novel approach.
Preparation of Hexamethyldisilazanomethacryloxyphenyl ketone (HDMK) and its copolymerization in the presence of acrylates
Authors: Naghash Hamid Javaherian , Amiri Ali
Published: October 2019

Purpose

This paper aims to improve some properties of poly (methyl methacrylate) by copolymerization with butyl acrylate (BA) monomer along with the incorporation of the stable and economical synthesized silicone-containing monomer hexamethyldisilazanomethacryloxyphenyl ketone (HDMK) into the copolymer matrix.

Design/methodology/approach

For this target solution copolymerization of methyl methacrylate (MMA), BA and HDMK were carried out using a 250 mL four-necked round-bottom flask. Before solution polymerization start-up, the reaction vessel was first charged with 34.8 mL toluene and heated to 170 Â°C with stirring and reflux cooling. A monomer mixture of 25.86 g (260 mmol) MMA, 26.40 g (200 mmol) BA, 3.00 g (8.60 mmol) HDMK and 0.45 g (2.00 mmol) dibenzoyl peroxide was added continuously from the dropping funnel over a period of 4 h.

Findings

The HDMK was successfully synthesized and the water resistance of acrylic resins was improved because of the existence of HDMK.

Research limitations/implications

The materials that were used in this research paper had a reasonably low cost. Also, the procedures for synthesis of monomers and polymers were extremely easy because there was no need for high pressure or temperature and no dangerous solvents were used.

Practical implications

The acrylic resin that contained HDMK was used to synthesis a white architectural paint for exterior coating. Examining the paint characteristics has shown acceptable washing and abrasion resistance, good brushing, excellent storage stability and great surface coating.

Originality/value

HDMK was synthesized for the first time.
Endovascular treatment of a hepatic artery pseudoaneurysm using a novel pericardium covered stent
Authors: Larner Brett , Maingard Julian , Ren Yifan , Kok Hong Kuan , Chandra Ronil V , Lee Michael J , Schelleman Anthony , Brooks Duncan Mark , Asadi Hamed
Published: October 2019

Visceral and renal artery aneurysms (VRAAs) and pseudoaneurysms are rare. Their increasing incidence is largely thought to be due to advances in medical imaging. Twenty percent of VRAAs occur in hepatic arteries, with approximately fifty percent of these represented by pseudoaneurysms, which are prone to spontaneous rupture. Many treatments for VRAAs exist, with the endovascular approach being favoured. Treatment aims to preserve visceral perfusion and exclude the aneurysm; however, complex aneurysms may require parent artery or end‐organ sacrifice. Covered stents allow rapid aneurysm exclusion while preserving parent artery patency, a favourable outcome when parent artery or end‐organ sacrifice is undesirable. The AneuGraft pericardium covered stent (PCS) combines the benefits of a low‐profile covered stent with those of a low immunogenic material. We describe the endovascular treatment of a patient with a hepatic artery pseudoaneurysm, where parent artery sacrifice was considered unacceptable. The AneuGraft PCS was used to provide immediate and complete exclusion, with dual antiplatelet therapy for 1 week, followed by single antiplatelet use. The procedure was a technical success, with preservation of the hepatic arteries and complete exclusion of the pseudoaneurysm. There were no complications immediately following the procedure or on post‐procedural follow‐up. The pseudoaneurysm remained excluded at 6‐week CT angiogram (CTA) follow‐up. This case describes a safe and effective method for completely excluding a complex pseudoaneurysm, utilising the AneuGraft PCS, allowing for the potential management of a wider range of aneurysms with unfavourable morphology.
Modelling misclassification in multi‐species acoustic data when estimating occupancy and relative activity
Authors: Wright Wilson J. , Irvine Kathryn M. , Almberg Emily S. , Litt Andrea R.
Published: October 2019

Surveying wildlife communities provides data for informing conservation and management decisions that affect multiple species. Autonomous recording units (ARUs) can efficiently gather community data for a variety of taxa, but generally require software algorithms to classify each recorded call to a species. Species classification errors are possible during this process and result in both false‐negative and false‐positive detections. Available approaches for analysing ARU data do not model the species classification probabilities, meaning erroneous detections are attributed to an omnibus source instead of the presence of another species. Additionally, counts of call recordings for each species are often summarized to binary detection data for analyses. Expanding statistical models to capture these nuances of ARU data would allow for improved inferences about occupancy and relative activity.

Motivated by bat acoustic surveys, we developed a model to analyse counts of call recordings from multiple species simultaneously while accounting for species classification errors. Our model expands on previously developed false‐positive occupancy models to better describe acoustic data. We used simulations to compare our model to other false‐positive occupancy models for an example scenario with ARU data from two species. We also analyse acoustic data for eight bat species in Montana using our model.

In simulations, single‐species models resulted in biased estimates of occupancy and relative activity because they failed to associate false positives with the presence of the second species. Models analysing binary observations ignored available information on relative activity and led to less precise estimates. Applying our model to bat acoustic data from Montana allowed for species‐specific estimates of occupancy and relative activity. This analysis illustrates the flexibility in our model framework while also highlighting the assumptions and data requirements for implementation. Specifically, additional information on the species classification probabilities is needed and we discuss considerations for reliably estimating these parameters.

Directly modelling the species classification probabilities allows for improved ecological inferences for both occupancy and relative activity using community ARU data. Our statistical framework helps address the challenges posed by acoustic data, allowing ecologists to better utilize this technology to monitor wildlife communities.
Longitudinal associations between family identification, loneliness, depression, and sleep quality
Authors: Wakefield Juliet R. H. , Bowe Mhairi , Kellezi Blerina , Butcher Andrew , Groeger John A.
Published: October 2019

Objectives

The prevalence of depression and loneliness is increasing in Western nations, and both have been shown to cause poor sleep quality, with evidence suggesting that loneliness also predicts depression. The Social Cure perspective can shed light on these relationships and thus informs the present study. Specifically, it was hypothesized that the extent of participants’ identification with a significant social group, their family, would positively predict sleep quality and that this relationship would be mediated by loneliness and depression.

Design

A two‐lave longitudinal online survey was used.

Methods

Participants completed an online survey at T1 (N = 387) and 1 year later at T2 (N = 122) assessing the extent to which they identified with their family. Their loneliness, depressive symptomology, and sleep quality/insomnia severity were also measured.

Results

Consistent with predictions, cross‐sectional and longitudinal serial mediation models indicated that family identification was a negative predictor of loneliness, which in turn was a positive predictor of depression, which predicted poor sleep quality/insomnia.

Conclusions

This is the first Social Cure study to explore the mediated relationship between social identification and sleep quality. As well as advancing the Social Cure perspective, these results have implications for how health professionals understand, prevent, and treat sleep problems.

Statement of contribution

What is already known on this subject?

The prevalence of depression and loneliness is increasing in Western nations, and both have been shown to cause poor sleep quality.

Weak social networks have been shown to predict restless sleep over time, and that depressed mood mediates this relationship.

What does this study add?

Family identification negatively predicted poor sleep quality cross‐sectionally.

Depression and loneliness positively predicted poor sleep quality over time.

Depression and loneliness mediated the family identification–sleep quality relationship over time.
Patterns and variation in the mammal parasite–glucocorticoid relationship
Authors: Defolie Charlotte , Merkling Thomas , Fichtel Claudia
Published: October 2019

Parasites are ubiquitous and can strongly affect their hosts through mechanisms such as behavioural changes, increased energetic costs and/or immunomodulation. When parasites are detrimental to their hosts, they should act as physiological stressors and elicit the release of glucocorticoids. Alternatively, previously elevated glucocorticoid levels could facilitate parasite infection due to neuroimmunomodulation. However, results are equivocal, with studies showing either positive, negative or no relationship between parasite infection and glucocorticoid levels. Since factors such as parasite type, infection severity or host age and sex can influence the parasite–glucocorticoid relationship, we review the main mechanisms driving this relationship. We then perform a phylogenetic meta‐analysis of 110 records from 65 studies in mammalian hosts from experimental and observational studies to quantify the general direction of this relationship and to identify ecological and methodological drivers of the observed variability. Our review produced equivocal results concerning the direction of the relationship, but there was stronger support for a positive relationship, although causality remained unclear. Mechanisms such as host manipulation for parasite survival, host response to infection, cumulative effects of multiple stressors, and neuro‐immunomodulatory effects of glucocorticoids could explain the positive relationship. Our meta‐analysis results revealed an overall positive relationship between glucocorticoids and parasitism among both experimental and observational studies. Because all experimental studies included were parasite manipulations, we conclude that parasites caused in general an increase in glucocorticoid levels. To obtain a better understanding of the directionality of this link, experimental manipulation of glucocorticoid levels is now required to assess the causal effects of high glucocorticoid levels on parasite infection. Neither parasite type, the method used to assess parasite infection nor phylogeny influenced the relationship, and there was no evidence for publication bias. Future studies should attempt to be as comprehensive as possible, including moderators potentially influencing the parasite–glucocorticoid relationship. We particularly emphasise the importance of testing hosts of a broad age range, concomitantly measuring sex hormone levels or at least reproductive status, and for observational studies, also considering food availability, host body condition and social stressors to obtain a better understanding of the parasite–glucocorticoid relationship.
Frugivory and seed dispersal by chelonians: a review and synthesis
Authors: Falcón Wilfredo , Moll Don , Hansen Dennis M.
Published: October 2019

In recent years, it has become clear that frugivory and seed dispersal (FSD) by turtles and tortoises is much more common than previously thought. We here review published and unpublished records of chelonian FSD, and assess the role of chelonians as seed dispersers, from individual species to the community level. We first discuss the distribution of chelonian FSD and the characteristics of the fruit and/or seed species eaten and dispersed by chelonians. We then use the seed dispersal efficiency framework to explore the quantitative and qualitative components of seed dispersal by tortoises and turtles, embarking on a journey from when the fruits and/or seeds are consumed, to when and where they are deposited, and assess how efficient chelonians are as seed dispersers. We finally discuss chelonian FSD in the context of communities and of chelonians as megafauna. A substantial proportion of the world's aquatic and terrestrial turtles and a major part of testudinid tortoises (71 species in 12 families) include fruits and/or seeds in their diet; fruits of at least 588 plant species in 121 families are ingested and/or dispersed by chelonians. For some chelonians, overall or in certain seasons, fruit may even form the largest part of their diet. Contrary to seed dispersal by lizards, the other major reptilian frugivores, chelonian FSD is not an island phenomenon in terms of geographic distribution. Nevertheless, on islands tortoises are often among the largest native terrestrial vertebrates – or were until humans arrived. We synthesise our knowledge of chelonian FSD, and discuss the relevance of our findings for conservation and restoration, especially in relation to rewilding with large and giant tortoises.
Love Them and Hate Them: The Developmental Appropriateness of Ambivalence in the Adolescent Sibling Relationship
Authors: Campione‐Barr Nicole , Killoren Sarah E.
Published: October 2019

The quality of sibling relationships has important implications for each sibling’s development, and not always in the expected ways, because both conflict and intimacy are associated with both positive and negative developmental outcomes. Additionally, these relationship qualities do not occur in isolation since sibling relationships are known as the quintessential love–hate relationship. The ambivalence (i.e., coexistence of positive and negative feelings) siblings experience toward one another during childhood and adolescence and the prevalence of this feeling make the sibling relationship unique. Ambivalence in the sibling relationship during adolescence is developmentally appropriate and may benefit individuals throughout life. In this article, we argue that adolescence is the tipping point in the sibling relationship that sets the stage for how healthy and engaged, or distant and uninvolved, relationships with siblings become in adulthood.
Safety and efficacy of endoscopic ultrasound‐guided gallbladder drainage combined with endoscopic retrograde cholangiopancreatography in the same session
Authors: Torres Yuste Raul , Garcia‐Alonso Francisco Javier , Sanchez‐Ocana Ramón , Cimavilla Roman Marta , Peñas Herrero Irene , Carbajo Ana Yaiza , De Benito Sanz Marina , Mora Cuadrado Natalia , De la Serna Higuera Carlos , Perez‐Miranda Manuel
Published: October 2019

Background and Aim

Endoscopic ultrasound‐guided gallbladder drainage (EUS‐GBD) is an emerging option for acute cholecystitis in non‐surgical candidates. Combining endoscopic retrograde cholangiopancreatography (ERCP) for common bile duct stones with EUS‐GBD in a single session might become a non‐surgical management strategy to comprehensively treat gallstone disease in selected patients.

Methods

Single‐center retrospective cohort study comparing outcomes between EUS‐GBD alone (group A) and single‐session ERCP combined with EUS‐GBD (group B). Consecutive patients who underwent EUS‐GBD with a lumen‐apposing metal stent (LAMS) between June 2011 and August 2018 were analyzed. Exclusion criteria were subjects included in randomized clinical trials, patients who had had ERCP within 5 days of EUS‐GBD, patients in whom ERCP or EUS‐GBD was carried out for salvage of one or the other procedure, and patients who underwent concurrent EUS‐guided biliary drainage.

Results

One hundred and nine consecutive patients underwent EUS‐GBD with LAMS during the study period. Seventy‐one patients satisfied the inclusion criteria and 34 patients were in group A and 37 in group B. Baseline characteristics were similar in both groups. There were no significant differences in technical (97.1% vs 97.3%; P = 0.19) and clinical success rates (88.2% vs 94.6%; P = 0.42) of EUS‐GBD in group A versus group B. Rate of adverse events was similar in both groups, five (14.7%) in group A versus five (13.5%) in group B.

Conclusions

Single‐session EUS‐GBD combined with ERCP has comparable rates of technical and clinical success to EUS‐GBD alone. A combined EUS‐GBD and ERCP procedure does not appear to increase adverse events and makes possible comprehensive treatment of gallstone disease by purely endoscopic means.
Improvements of right ventricular function and hemodynamics after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension
Authors: Kanar Batur Gonenc , Mutlu Bülent , Atas Halil , Akaslan Dursun , Yıldızeli Bedrettin
Published: October 2019

Purpose

Right ventricular (RV) function is an important factor in the prognosis of chronic thromboembolic pulmonary hypertension (CTEPH) in patients. In our study, we aimed to evaluate the timing and magnitude of regional RV function before and after balloon pulmonary angioplasty (BPA) using speckle tracking echocardiography (STE) and their relation to clinical and hemodynamic parameters in patients with CTEPH.

Material and Method

We enrolled 20 CTEPH patients and 19 healthy subjects in our study. Enrolled patients underwent echocardiography, right heart catheterization (RHC), and 6‐minute walk distance (6MWD) test at baseline and after the BPA.

Results

In hemodynamic RHC measurements and clinical evaluations, mean pulmonary artery pressure (median: 53.5 mm Hg vs 37.0 mm Hg, P = .001) and pulmonary vascular resistance (median: 12 Wood units [WU] vs 7 WU, P = .001) and pro‐brain natriuretic peptide level decreased and 6MWD increased after BPA sessions. There was no statistically significant difference between before and after the BPA sessions in conventional echocardiographic measurements. In STE analysis, the electromechanical delay (EMD) between RV free wall (RVF) and LV lateral wall (LVL) (median: 65 ms vs 47.5 ms, P = .01) and RV peak systolic strain dispersion index (52 ms vs 29 ms, P = .001) were higher in patients with CTEPH than healthy controls before the BPA. Both these parameters decreased significantly after BPA.

Conclusion

Chronic thromboembolic pulmonary hypertension was associated with RV electromechanical delay and dispersion based on the STE analysis. Balloon pulmonary angioplasty might have an important impact on the improvement of both RV function and hemodynamics.
Family Communication Patterns and the Mediating Effects of Support and Resilience on Students' Concerns About College
Authors: Dorrance Hall Elizabeth , Scharp Kristina M. , Sanders Matthew , Beaty Loretta
Published: October 2019

Objective

To identify first‐year undergraduate students' concerns about college and examine how family support and resilience influence the relationships between family communication patterns and adjustment to college.

Background

Nearly half of undergraduate college students in the United States do not graduate within 6 years. Low graduation rates come at high costs to students and universities. A deeper understanding of the family factors that contribute to adjustment concerns may provide retention‐focused intervention opportunities.

Method

Survey data collected from precollege students (N = 2,252) were used to test a moderated mediation model in which family communication patterns are associated with adjustment concerns through resilience and family support.

Results

Conversation orientation was related to higher family support, whereas conformity was related to lower resilience and family support. Interaction results indicate that the effects of conversation orientation on some adjustment concerns depended on conformity ratings. Resilience mediated the relationship between the orientations and adjustment concerns.

Conclusion

Conversation and conformity orientation play a role in perceptions of family support, student resilience, and an array of concerns held by students as they enter college.

Implications

Parents may play an important role in helping their child adjust to college through the family communication environments they create and reinforce from childhood and through the support they provide during the transition to college.
Efficacy and safety of prolonged daily hemodialysis in critically ill children weighing less than 10 kg
Authors: Ali Uma S. , Arya Manish Kumar
Published: October 2019

Introduction

Extracorporeal renal replacement therapy may be needed in those infants in whom peritoneal dialysis is not feasible or is ineffective. Prolonged daily hemodialysis (PDHD) remains the only available extracorporeal dialytic modality in children weighing less than 10 kg, in setups where continuous renal replacement therapy is unavailable and sustained low‐efficiency dialysis is not feasible due to lack of dedicated HD machines capable of delivering very low dialysate flows. The use of PDHD in critically ill children weighing less than 10 kg has not received much attention.

Methods

Retrospective analysis of the efficacy and safety of PDHD in critically ill children weighing less than 10 kg.

Findings

Four critically ill children received a total of 49 sessions of PDHD for acute kidney injury (AKI) associated with sepsis and multiorgan dysfunction syndrome (MODS). PDHD was delivered for a duration of 6 to 8 hours daily with low ultrafiltration rates, low blood flow rates but with dialysate rates that were four times the blood flow rates, due to limitations of minimal dialysate flow rate on standard machines. The mean duration of the sessions was 6.59 ± 1.61 hours. Mean hourly ultrafiltrate (UF) rate during the sessions was 9.28 ± 2.57/kg/hour with mean patient fluid removal rate of 5.4 ± 2.56 mL/kg/hour. Predialysis serum creatinine decreased to 30% of the starting value by the fourth hemodialysis (HD) session. Thirty‐three (67.4%) sessions were heparin free. Intradialytic hypotension occurred in 10 (20.4%) sessions. Premature termination of the session occurred in six (12.4%), due to hypotension in two and filter clotting in four. Hypokalemia was seen in 12 (24.4%) and hypophosphatemia in 6 (12.24%). All four patients survived. On follow‐up, three are dialysis free and one is on maintenance hemodialysis.

Conclusion

PDHD is effective and safe in critically ill small children.
Characterisation of isocitrate dehydrogenase 1/isocitrate dehydrogenase 2 gene mutation and the d‐2‐hydroxyglutarate oncometabolite level in dedifferentiated chondrosarcoma
Authors: Mohammad Nissreen , Wong Derek , Lum Amy , Lin Jonah , Ho Julie , Lee Cheng‐Han , Yip Stephen
Published: October 2019

Aims

Dedifferentiated chondrosarcoma (DDCHS) is an aggressive type of chondrosarcoma that results from high‐grade transformation of a low‐grade chondrosarcoma. Mutations in the isocitrate dehydrogenase (IDH) 1 gene and the IDH2 gene that lead to increased d‐2‐hydroxyglutarate (2HG) oncometabolite production, promoting tumorigenesis, have been recently described in low‐grade cartilaginous neoplasms. The aims of this study were to examine the prevalence of IDH mutations in a single‐institution cohort of DDCHS cases and correlate 2HG levels with mutation status.

Methods and results

We examined a series of 21 primary DDCHS cases by using Sanger sequencing and quantitative polymerase chain reaction genotyping to look for IDH1/IDH2 mutations, and evaluated the 2HG levels in formalin‐fixed paraffin‐embedded tumour and matched normal tissue samples by using a fluorometric assay. Seventy‐six per cent of DDCHS cases (16/21) harboured a heterozygous IDH1 or IDH2 mutation. Six of 14 IDH‐mutated DDCHS cases showed elevated 2HG levels in tumour tissue relative to matched normal tissue. There were no consistent histological or disease‐specific survival differences between IDH‐mutated tumours and wild‐type tumours.

Conclusions

Our study confirms the frequent presence of a variety of IDH1 and IDH2 mutation variants, indicating that a sequencing‐based approach is required for DDCHS if IDH is to be used as a diagnostic marker. Similarly to other IDH‐mutated tumour types, IDH‐mutated DDCHS cases show elevated 2HG levels, indicating that the oncometabolite activity of 2HG may contribute to DDCHS oncogenesis and progression.
SOCIAL INSURANCE AND OCCUPATIONAL MOBILITY
Authors: Cubas German , Silos Pedro
Published: October 2019

This article studies how insurance from progressive taxation improves the matching of workers to occupations. We propose an equilibrium dynamic assignment model to illustrate how social insurance encourages mobility. Workers experiment to find their best occupational fit in a process filled with uncertainty. Risk aversion and limited earnings insurance induce workers to remain in unfitting occupations. We estimate the model using microdata from the United States and Germany. Higher earnings uncertainty explains the U.S. higher mobility rate. When workers in the United States enjoy Germany's higher progressivity, mobility rises. Output and welfare gains are large.
Dispersion behavior of HfC‐based nanopowders in ethanol
Authors: Feng Lun , Zhao Lin , Lee Sea‐Hoon
Published: October 2019

The dispersion behavior of two different types of ultrafine HfC‐based powders in ethanol was investigated using polyethyleneimine (PEI) as a dispersant. The first type was synthesized by carbothermal reduction using a modified spark plasma sintering technique (d50: 125 nm). For the 10 wt% HfC suspensions, the highest zeta potential value (67.7 mV), the least sediment after sedimentation test for one day, and finest particle sizes were obtained when the concentration of PEI was 2.0 wt%. The concentrated HfC slurries with a solid loading of 40 vol% were achieved using 1.0 wt% PEI. The second type was mixing the HfC powder with HfSi2‐C additives using a high‐energy ball milling. The concentrated HfC slurry containing 20 wt% of HfSi2‐C sintering additives was prepared up to 50 vol% solid loading using 0.50 wt% PEI. This is the first report for producing highly concentrated HfC‐based nano slurries, which were highly suitable for the wet process of ultrahigh‐temperature ceramic matrix composites (UTHCMCs).
The five dimensions of B cell tolerance
Authors: Platt Jeffrey L. , Garcia de Mattos Barbosa Mayara , Cascalho Marilia
Published: October 2019

B cell tolerance has been generally understood to be an acquired property of the immune system that governs antibody specificity in ways that avoid auto‐toxicity. As useful as this understanding has proved, it fails to fully explain the existence of auto‐reactive specificities in healthy individuals and contribution these may have to health. Mechanisms underlying B cell tolerance are considered to select a clonal repertoire that generates a collection of antibodies that do not bind self, ie tolerance operates more or less in three dimensions that largely spare autologous cells and antigens. Yet, most B lymphocytes in humans and probably in other vertebrates are auto‐reactive and absence of these auto‐reactive B cells is associated with disease. We suggest that auto‐reactivity can be embodied by extending the concept of tolerance by two further dimensions, one of time and circumstance and one that allows healthy cells to actively resist injury. In this novel concept, macromolecular recognition by the B cell receptor leading to deletion, anergy, receptor editing or B cell activation is extended by taking account of the time of development of normal immune responses (4th dimension) and the accommodation (or tolerance) of normal cells to bound antibody, activation of complement, and interaction with inflammatory cells (fifth dimension). We discuss how these dimensions contribute to understanding B cell biology in health or disease.
Speaking up about patient safety in psychiatric hospitals – a cross‐sectional survey study among healthcare staff
Authors: Schwappach David L. B. , Niederhauser Andrea
Published: October 2019

Speaking up is an important communication strategy to prevent patient harm. The aim of this study was to examine speak up‐related behaviour and climate for the first time in psychiatric hospitals. A cross‐sectional survey was conducted among healthcare workers (HCWs) in six psychiatric hospitals with nine sites in Switzerland. Measures assessed speak up‐related behaviour with 11 items organized in three scales (the frequency of perceived safety concerns, the frequency of withholding voice, and the frequency of speaking up). Speak up‐related climate was assessed by 11 items organized in 3 subscales (psychological safety for speaking up, encouraging environment for speaking up, and resignation). Statistical analyses included descriptive statistics, reliability, correlations and multiple regression analysis, confirmatory factor analysis, and analysis of variance for comparing mean scores between professional groups. A total of 817 questionnaires were completed (response rate: 23%). In different items, 45%–65% of HCWs reported perceived safety concerns at least once during the past four weeks. Withholding voice was reported by 13–25% of HCWs, and speaking up was reported by 53%–72% of HCWs. Systematic differences in scores were found between professional groups (nurses, doctors, psychologists) and hierarchical groups (lower vs higher status). The vignette showed that hierarchical level and perceived risk of harm for the patient were significant predictors for the self‐reported likelihood to speak up. Situations triggering safety concerns occur frequently in psychiatric hospitals. Speaking up and voicing concerns should be further promoted as an important safety measure.
Molecular and morphological evidence reveals hybridisation between two endemic cyprinid fishes
Authors: Ramoejane Mpho , Gouws Gavin , Swartz Ernst R. , Sidlauskas Brian L. , Weyl Olaf L. F.
Published: October 2019

The geographic occurrence of moggel Labeo umbratus × mud fish Labeo capensis hybrids and the threat of hybridisation to the genetic integrity of L. umbratus were investigated. Genetic evidence from mtDNA cytb and nDNA s7 intron sequence data indicated probable interspecific hybridisation in two impoundments, Hardap Dam (Orange River Basin, Namibia) and Darlington Dam (Sundays River Basin, Eastern Cape, South Africa). Some putative hybrids were morphologically identifiable on account of their meristic and morphometric intermediacy to the parent species. Human activities appear to drive the observed hybridisation, either through dam construction and direct stocking of L. umbratus or via translocation of Labeo capensis and the previously isolated Orange River lineage of L. umbratus into the southern‐flowing systems by inter‐basin water transfers. It is recommended that further translocation of fish from these areas should be avoided.
Is there a need for postoperative antibiotics after third molar surgery? A 5‐year retrospective study
Authors: Menon Rohit K. , Kar Yan Li , Gopinath Divya , Botelho Michael G.
Published: October 2019

Aim

Randomized controlled trials might be reporting a higher postoperative infection rate for third molar surgery compared to other study designs due to unclear criteria for the classification of “infections”. The aim of the present retrospective study was to assess the infection rate after third molar surgery with and without postoperative antibiotic prescription.

Methods

Case records of patients who underwent third molar extractions at the Prince Philip Dental Hospital in Hong Kong between 3 July 2012 and 22 June 2017 were evaluated retrospectively. Data extraction was performed for indications, clinical and radiographic findings, antibiotic treatment, postoperative complications, and treatment for postoperative infection. The odds ratio (OR) for postoperative infection was estimated.

Results

In total, 1615 extracted over 5 years from 992 patient records were included in the final analysis. Antibiotics were prescribed postoperatively for 44% of the extractions. The overall infection rate was 2.05%. There was no significant difference in infection rates between the groups which underwent extractions with or without antibiotics (OR = .68; P = .289). We found a significantly higher risk for infections with increasing age (P = .002).

Conclusion

Infection rates after third molar extraction is minimal in the current setting, with no significant benefit from postoperative antibiotic prescription.
Role of kisspeptin neurons as a GnRH surge generator: Comparative aspects in rodents and non‐rodent mammals
Authors: Matsuda Fuko , Ohkura Satoshi , Magata Fumie , Munetomo Arisa , Chen Jing , Sato Marimo , Inoue Naoko , Uenoyama Yoshihisa , Tsukamura Hiroko
Published: October 2019

Ovulation is an essential phenomenon for reproduction in mammalian females along with follicular growth. It is well established that gonadal function is controlled by the neuroendocrine system called the hypothalamus‐pituitary‐gonadal (HPG) axis. Gonadotropin‐releasing hormone (GnRH) neurons, localized in the hypothalamus, had been considered to be the head in governing the HPG axis for a long time until the discovery of kisspeptin. In females, induction of ovulation and folliculogenesis has been linked to a surge mode and pulse mode of GnRH releases, respectively. The mechanisms of how the two modes of GnRH are differently regulated had long remained elusive. The discovery of kisspeptin neurons, distributed in two hypothalamic nuclei, such as the arcuate nucleus in the caudal hypothalamus and preoptic area or the anteroventral periventricular nucleus in the rostral hypothalamic regions, and analyses of the detailed functions of kisspeptin neurons have led marked progress on the understanding of different mechanisms regulating GnRH surges (ovulation) and GnRH pulses (folliculogenesis). The present review will focus on the role of kisspeptin neurons as the GnRH surge generator, including the sexual differentiation of the surge generation system and factors that regulate the surge generator. Comparative aspects between mammalian species are especially focused on.
Comparison of the efficacy of the immediate‐release and osmotic push–pull system formulations of nifedipine for tocolysis
Authors: Inan Cihan , Sayin Cenk , Dolgun Nihal , Uzun Isil , Erzincan Selen G. , Sutcu Havva , Varol Fusun
Published: October 2019

Aim

To compare the immediate‐release (IR) and osmotic push–pull system formulations of nifedipine used for tocolysis in prolonging pregnancy, neonatal outcomes and maternal–fetal adverse effects.

Methods

We evaluated 140 pregnant women who received the IR (n = 72) and osmotic push–pull system (n = 68) formulations of nifedipine for tocolysis due to threatened preterm labor between 240/7 and 336/7 weeks of gestation. Groups were compared in terms of efficacy of tocolysis in prolonging pregnancy for more than 48 h, 7 days and up to 37 weeks of gestation, total number of days gained for prolonging pregnancy, delivery weeks, maternal–fetal adverse effects and neonatal outcomes including ventilation support, need for intubation or surfactant, intraventricular hemorrhage, respiratory distress syndrome, necrotizing enterocolitis, admission to neonatal intensive care unit, neonatal death, Apgar scores at the 1st and 5th minutes.

Results

There was no significant difference between the two groups in prolonging pregnancy for more than 48 h or 7 days, total number of days gained after tocolysis initiation, delivery weeks, the number of births at 340/7–366/7 weeks or after 37 weeks of gestation (P > 0.05). Maternal–fetal adverse effects and neonatal outcomes were similar in both groups (P > 0.05).

Conclusion

The efficacy of IR and osmotic push–pull system formulations of nifedipine have similar effects in terms of tocolysis and neonatal outcomes, adverse effects. Osmotic push–pull system formulation of nifedipine may be an alternative medication in tocolytic therapy due to its ease of use and the absence of loading dose necessity.
An Integrated Relational Framework of Depressed Mood and Anhedonia During Pregnancy
Authors: Brock Rebecca L. , Franz Molly R. , Ramsdell Erin L.
Published: October 2019

Objective

The aim of the present study was to test a unified framework that integrates several theories into a cohesive model to explain the interplay between neuroticism and intimate relationship quality as risk factors for prenatal depression.

Background

There is a notable spike in risk for depression during pregnancy, and the processes unfolding in the interparental relationship during this important time in the family life cycle might serve to mitigate or enhance this risk. Yet there is a need for theory‐driven research integrating multiple conceptual frameworks to explicate the role of intimate relationship quality in depression.

Method

In a sample of 154 pregnant, cohabiting couples, multiple domains of intimate relationship quality were assessed using a semistructured clinical interview. An ecologically valid assessment of core depressive features was implemented, such that daily reports of depressed mood and anhedonia captured the pervasiveness of those symptoms for 2 weeks.

Results

The hypothesized, integrated model was supported for the following two dimensions of intimate relationship quality: conflict management for women and partner support for men. Neuroticism predicted depressive symptoms indirectly through poorer relationship quality and interacted with poorer relationship quality to influence depressive symptoms. In addition, poor sexual quality predicted paternal depressive symptoms, and this effect intensified at higher levels of neuroticism; however, neuroticism did not predict sexual quality.

Conclusions

This integrated approach to studying risk for depression has implications for future research and clinical practice, particularly for clinicians working with pregnant couples when one or both partners are experiencing symptoms of depression.
Imaging Functional Recovery Following Ischemic Stroke: Clinical and Preclinical fMRI Studies
Authors: Crofts Andrew , Kelly Michael E. , Gibson Claire L.
Published: October 2019

Disability and effectiveness of physical therapy are highly variable following ischemic stroke due to different brain regions being affected. Functional magnetic resonance imaging (fMRI) studies of patients in the months and years following stroke have given some insight into how the brain recovers lost functions. Initially, new pathways are recruited to compensate for the lost region, showing as a brighter blood oxygen‐level‐dependent (BOLD) signal over a larger area during a task than in healthy controls. Subsequently, activity is reduced to baseline levels as pathways become more efficient, mimicking the process of learning typically seen during development. Preclinical models of ischemic stroke aim to enhance understanding of the biology underlying recovery following stroke. However, the pattern of recruitment and focusing seen in humans has not been observed in preclinical fMRI studies that are highly variable methodologically. Resting‐state fMRI studies show more consistency; however, there are still confounding factors to address. Anesthesia and method of stroke induction are the two main sources of variability in preclinical studies; improvements here can reduce variability and increase the intensity and reproducibility of the BOLD response detected by fMRI. Differences in task or stimulus and differences in analysis method also present a source of variability. This review compares clinical and preclinical fMRI studies of recovery following stroke and focuses on how refinement of preclinical models and MRI methods may obtain more representative fMRI data in relation to human studies.