bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of fire exposed composite girders under dominant flexural and shear loading
Authors: Naser Mohannad , Kodur Venkatesh 
Published: July 2017

PurposeThis paper aims to present results from numerical studies on the response of fire exposed composite girders subjected to dominant flexural and shear loading. A finite element-based numerical model was developed to trace the thermal and structural response of composite girders subjected to simultaneous structural loading and fire exposure. This model accounts for various critical parameters including material and geometrical nonlinearities, property degradation at elevated temperatures, shear effects, composite interaction between concrete slab and steel girder, as well as temperature-induced local buckling. To generate test data for validation of the model, three composite girders, each comprising of hot-rolled (standard) steel girder underneath a concrete slab, were tested under simultaneous fire and gravity loading.Design/methodology/approachThe validated model was then applied to investigate the effect of initial geometric imperfections, load level, thickness of slab and stiffness of shear stud on fire response of composite girders.FindingsResults from experimental and numerical analysis indicate that the composite girder subjected to flexural loading experience failure through flexural yielding mode, while the girders under shear loading fail through in shear web buckling mode. Further, results from parametric studies clearly infer that shear limit state can govern the response of fire exposed composite girders under certain loading configuration and fire scenario.Originality/valueThis paper presents results from numerical studies on the response of fire exposed composite girders subjected to dominant flexural and shear loading.
Fire resistance of extruded hollow-core slabs
Authors: Hertz Kristian , Giuliani Luisa , Sørensen Lars Schiøtt 
Published: July 2017

Purpose
Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of load-bearing capacity of hollow-core slabs when exposed to fire.

Design/methodology/approach
Furthermore, it compares theoretical calculation and assessment according to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs.

Findings
Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found.

Originality value
For the first time, the mechanisms responsible for loss of load-bearing capacity are identified, and test results and calculation approach are for the first time applied in accordance with each other for assessment of fire resistance of the structure.
Thermal behaviour of unstressed and stressed high strength concrete containing polypropylene fibers at elevated temperature
Authors: Cree Duncan , Pliya Prosper , Green Mark F. , Noumowé Albert 
Published: July 2017

Purpose
The purpose of this paper is to evaluate high strength concrete (HSC) containing polypropylene fibers (PP-fibers) at high temperature under a compressive load.

Design/methodology/approach
The use of PP fibers in HSC is known to reduce and at times eliminate the risk of spalling. HSC containing 0, 1 and 2 kg/m3 of PP-fibers were subjected to various temperatures from 20°C to 150°C, 300°C and 450°C and evaluated in a “hot condition”. One group of specimens was in a non-stressed condition during heating (unstressed hot), while a second group was subjected to an initial preload of 40 per cent of the room temperature compressive strength during the heating (stressed hot).

Findings
Results showed that stressed concrete containing PP-fibers had lower thermal gradients (the temperature difference between the surface and center temperatures as a function of radial distance) and a decrease in relative porosity. However, the compressive strength of stressed specimens was improved with or without fibers as compared to that of the unstressed HSC. The increased stress levels due to concrete expansion at elevated temperature were also reported. The PP-fibers did not have a significant effect on the compressive strength of stressed concrete as compared to the unstressed state.

Originality/value
This paper reports the compressive strength of PP-fibers in HSC at elevated temperature with and without a pre-load.
Mechanical properties of low-strength concrete at exposure to elevated temperatures
Authors: Rafi Muhammad Masood , Aziz Tariq , Lodi Sarosh Hashmat 
Published: July 2017

PurposeThis paper aims to present the results of testing of low-strength concrete specimens exposed to elevated temperatures. These data are limited in the existing literature and do not exist in Pakistan.Design/methodology/approachAn experimental testing programme has been employed. Cylindrical specimens of 100 × 200 mm were used in the testing programme. These were heated at temperatures which were varied from 100°C to 900°C in increment of 100°C. Similar specimens were tested at ambient temperature as control specimens. The compressive and tensile properties of heat treated specimens were determined.FindingsThe colour of concrete started to change at 300°C and hairline cracks appeared at 400°C. Explosive spalling was observed in few specimens in the temperature range of 400°C-650°C which could be attributed to the pore pressure generated by steam. Significant loss of concrete compressive strength occurred on heating temperatures larger than 600°C, and the residual compressive strength was found to be 15 per cent at 900°C. Residual tensile strength of concrete became less than 10 per cent at 900°C. The loss of concrete stiffness reached 85 per cent at 600°C. Residual Poisson’s ratio of concrete increased at high temperatures and became nearly six times larger at 900°C as compared to that at ambient temperature.Research limitations/implicationsThe parameters of the study included heating temperature and effects of temperature on strength and stiffness properties of the concrete specimens.Practical implicationsBuilding fire incidents have increased in Pakistan. As a large number of reinforced concrete (RC) buildings exist in the country, the data related to elevated temperature properties of concrete are required. These data are not available in Pakistan presently. The study aims at providing this information for the design engineers to enable them to assess and increase fire resistance of RC structural members.Originality/valueThe presented study is unique in its nature in that there is no published contribution to date, to the best of authors’ knowledge, which has been carried out to assess the temperature-dependent mechanical properties of concrete in Pakistan.
Exploring the antecedents of ambidexterity: a taxonomic approach
Authors: Asif Muhammad 
Published: July 2017

PurposeAmbidexterity is the ability of an organization to balance exploitation and exploration. Ambidextrous organizations perform better in managing productivity-innovation dilemma. Although the literature on ambidexterity has expanded, much less attention has been paid to the antecedents of ambidexterity. The purpose of this paper is to explore the antecedents of ambidexterity and develop a multi-level taxonomy of the antecedents.Design/methodology/approachBased on an extensive review of the literature, the paper develops criteria for categorizing the antecedents and then develops a taxonomy of the antecedents.FindingsTwo taxonomy frameworks have been developed: one is based on infrastructural elements, including organizational structures, processes, and context, while the other is based on different organizational levels (i.e. organizational, group, and individual) at which different antecedents exist. Most of the antecedents of ambidexterity reported in the literature fall in the category of “processes” – both individual/social and technical/procedural.Practical implicationsThe paper provides an enhanced understanding of the antecedents of ambidexterity, how they relate to each other, and how they can be grouped together. The framework can help managers to apply the antecedents at various organizational levels, resulting in a more structured approach to ambidexterity.Originality/valueThe key contribution of the paper is in providing a multi-level understanding of the antecedents of ambidexterity. To the best of the author’s knowledge, such a taxonomy of the antecedents of ambidexterity has not been provided in previous publications.
Mutual funds in Greece: case study of domestic equity mutual funds during a financial crisis
Authors: Koutsokostas Drosos , Papathanasiou Spyros 
Published: July 2017

Purpose
The purpose of this paper is to examine the performance of Greek equity mutual funds for the period 2012-2016, analyzing further the selectivity and market timing ability, and short-term performance persistence for the period 2015-2016.

Design/methodology/approach
Utilizing a survivorship-bias-controlled sample of 25 funds and daily data, the authors use single-index (Jensen, 1968) and multi-factor (Carhart, 1997) models to evaluate risk-adjusted returns using the General Index of Athens Stock Exchange as a benchmark. The Treynor-Mazuy (1966) and Henriksson-Merton (1981) models are used to assess the stock selection and market timing abilities of fund managers. In order to investigate short-term performance persistence, the authors implement a variety of parametric (Bollen and Busse, 2005) and nonparametric tests (Malkiel, 1995; Brown and Goetzmann, 1995; Kahn and Rudd, 1995).

Findings
Results show that the funds underperformed the General Index, mainly due to the managers’ market timing inability. Furthermore, weak evidence for short-term performance persistence has been documented.

Research limitations/implications
Checking for performance persistence, it was impossible to rank funds and form deciles according to their estimated abnormal returns, as in Bollen and Busse (2005), due to the small number of mutual funds operating in Greece.

Originality/value
Empirical studies regarding the performance of Greek equity mutual funds are still limited. Therefore, this paper intends to fill this gap by providing further evidence of performance evaluation.
Rethinking educational tourism: proposing a new model and future directions
Authors: McGladdery Christine A. , Lubbe Berendien A. 
Published: July 2017

PurposeEducational tourism is under-researched in the literature. The purpose of this paper is to argue that this stems from a lack of consensus regarding the nature and scope of educational tourism as a theoretical concept and market segment.Design/methodology/approachThrough a review of research over the last decade and a half, the paper aims at providing a concise overview of the key perspectives and concepts in educational tourism whilst highlighting the potential for future directions of the sector.FindingsRitchie’s (2003) segmentation model of educational tourism is usually considered the international standard for writing on the subject. However, it excludes certain sectors of tourism that may be considered educational. In response to this, a new conceptual model is presented. Further research is needed to understand the schools’ educational tourism market. When international educational tourism is considered, the majority of empirical research and academic debate has originated in the closely related field of international education. Educational tourism has the potential for hybridisation with other segments of tourism and non-tourism sectors and to contribute towards global peace.Originality/valueThis paper offers an alternative process-driven and outcomes-based conceptual model of educational tourism. It identifies directions for future research in schools’ and international educational tourism and proposes a typology to aid hybridisation of the phenomenon with other sectors. Finally, it discusses the potential of educational tourism to foster peace through the integration of global learning into touristic practice.
Evolutionary changes of Hox genes and relevant regulatory factors provide novel insights into mammalian morphological modifications
Authors: LI Kui , SUN Xiaohui , CHEN Meixiu , SUN Yingying , TIAN Ran , WANG Zhengfei , XU Shixia , YANG Guang 
Published: July 2017

AbstractThe diversity of body plans of mammals accelerates the innovation of lifestyles and the extensive adaptation to different habitats, including terrestrial, aerial and aquatic habitats. However, the genetic basis of those phenotypic modifications, which have occurred during mammalian evolution, remains poorly explored. In the present study, we synthetically surveyed the evolutionary pattern of Hox clusters that played a powerful role in the morphogenesis along the head–tail axis of animal embryos and the main regulatory factors (Mll, Bmi1 and E2f6) that control the expression of Hox genes. A deflected density of repetitive elements and lineage‐specific radical mutations of Mll have been determined in marine mammals with morphological changes, suggesting that evolutionary changes may alter Hox gene expression in these lineages, leading to the morphological modification of these lineages. Although no positive selection was detected at certain ancestor nodes of lineages, the increased ω values of Hox genes implied the relaxation of functional constraints of these genes during the mammalian evolutionary process. More importantly, 49 positively‐selected sites were identified in mammalian lineages with phenotypic modifications, indicating adaptive evolution acting on Hox genes and regulatory factors. In addition, 3 parallel amino acid substitutions in some Hox genes were examined in marine mammals, which might be responsible for their streamlined body.
Inter‐group associations in Mongolian gerbils: Quantitative evidence from social network analysis
Authors: DENG Ke , LIU Wei , WANG Dehua 
Published: July 2017

AbstractAnimals often interact non‐randomly with conspecifics, and association preferences can differ across life‐history stages to maximize individuals' fitness. Mongolian gerbils (Meriones unguiculatus) are a social rodent that live in highly seasonal habitats and display seasonal fluctuations in population density, growth rate and the size of overlapped home ranges. Nevertheless, whether gerbils modify their social relationships at different life‐history stages remains unknown. Here, we used social network analysis to examine whether social associations differ between the sexes and between life‐history stages in a wild population of Mongolian gerbils. We quantified social attributes at both group level (assortativity) and individual level (social differentiation and degree, closeness and betweenness centrality); these attributes reflect individuals' social preferences and their potential influence on others in the network. We found that both male and female gerbils established fewer inter‐group social connections during the food‐hoarding season than during the breeding season, revealing constraints on sociality. Similarly, during the food‐hoarding season, degree centrality and social differentiation increased significantly whereas closeness and betweenness centrality decreased significantly. Together, these results suggest that gerbils have relatively more partners and preferred associations and decreased influence over others in the network during the food‐hoarding season. In addition, we found no significant difference in any of the social attribute between males and females, but there was a significant interaction effect between sex and season on degree, closeness and betweenness centrality. Our results demonstrate that Mongolian gerbils adjust their association strategies to adapt to the changes of life history. Such adjustments may balance the costs/benefits associated with survival and reproduction.
Emergency appendicectomy in Australia: findings from a multicentre, prospective study
Authors: Arthur Thomas , Gartrell Richard , Manoharan Bavahuna , Parker David ,   QUEST Collaboration
Published: July 2017

AbstractBackgroundEmergency appendicectomy is the most common emergency surgical procedure performed in Australia. Despite this frequency, there is a relative paucity of contemporary, broad‐based, local data that examine how emergency appendicectomies are currently performed and what are the outcomes from these operations.MethodsA multicentre, prospective, observational study was performed. Patients were recruited by local investigators for a period of 2 months with 30‐day follow‐up. Patients were eligible for study inclusion if they underwent an emergency appendicectomy for suspected acute appendicitis. The primary outcome of the study was the negative appendicectomy rate (NAR), with secondary outcomes including 30‐day complication rates, method of operation and conversion rates.ResultsA total of 1189 patients were recruited across 27 centres. The NAR across all centres was 19.0%. 98.2% of appendicectomies were performed with a laparoscopic‐first approach. The rate of conversion from laparoscopy to open operation was 2.4%. 9.4% of patients were recorded as having one or more of the following complications: readmission (6.6%), surgical site infection (1.9%), intra‐abdominal abscess (2.7%) or further intervention (1.5%). Patients who had an open operation had higher rates of readmission and surgical site infection.ConclusionThe NAR found in this study is within the traditional measures of acceptance; however, this rate is high when measured against modern international benchmarks.
Prognostic value of positron emission tomography/computed tomography for adjuvant chemotherapy of colon cancer
Authors: Baik HyungJoo , Lee Seok Mo , Seo Sang Hyuk , An Min Sung , Kim Kwang Hee , Bae Ki Beom , Oh Min Kyung , Hong Kwan Hee 
Published: July 2017

BackgroundTo assess the prognostic value of preoperative 18F‐fluorodeoxyglucose positron emission tomography/computed tomography in patients with high‐risk stage II or stage III colon cancer who underwent FOLFOX chemotherapy.MethodsThe study included 166 patients with high‐risk stage II or stage III colon cancer who received FOLFOX4 chemotherapy. Retrospective patient data were analysed including pathological stage, histology, disease‐free survival (DFS) and the maximum standardized uptake value (SUVmax) of the primary tumour on 18F‐fluorodeoxyglucose positron emission tomography/computed tomography. The primary end point was DFS.ResultsThere were recurrences in 29 of the 166 patients (17.4%). Measuring the area under the receiver operating characteristic curve, the cut‐off value of SUVmax with maximum sensitivity and specificity was 10.95. Using the Kaplan–Meier method, the DFS of the patients categorized by SUVmax tended to differ (P = 0.055). In univariate analyses, the risk factors for DFS were age over 70 years, higher N stage and neural invasion. SUVmax ≤ 10.95 showed a tendency, but was not significant (P = 0.0604). In multivariate analyses, the risk factors for DFS were age over 70 and neural invasion.ConclusionsThe results of this study suggest that high fluorodeoxyglucose uptake of the primary mass in high‐risk stage II and stage III colon cancer does not significantly correlate with DFS.
Promoting Positive Youth Development Through School‐Based Social and Emotional Learning Interventions: A Meta‐Analysis of Follow‐Up Effects
Authors: Taylor Rebecca D. , Oberle Eva , Durlak Joseph A. , Weissberg Roger P. 
Published: July 2017

This meta‐analysis reviewed 82 school‐based, universal social and emotional learning (SEL) interventions involving 97,406 kindergarten to high school students (Mage = 11.09 years; mean percent low socioeconomic status = 41.1; mean percent students of color = 45.9). Thirty‐eight interventions took place outside the United States. Follow‐up outcomes (collected 6 months to 18 years postintervention) demonstrate SEL's enhancement of positive youth development. Participants fared significantly better than controls in social‐emotional skills, attitudes, and indicators of well‐being. Benefits were similar regardless of students’ race, socioeconomic background, or school location. Postintervention social‐emotional skill development was the strongest predictor of well‐being at follow‐up. Infrequently assessed but notable outcomes (e.g., graduation and safe sexual behaviors) illustrate SEL's improvement of critical aspects of students’ developmental trajectories.
Prediction of outcome after curative surgery for colorectal cancer: preoperative haemoglobin, C‐reactive protein and albumin
Authors: Egenvall M. , Mörner M. , Martling A. , Gunnarsson U. 
Published: July 2017

AbstractAimThe aim was to evaluate a scoring system using the values of preoperative haemoglobin, C‐reactive protein (CRP) and albumin to predict colorectal cancer recurrence and survival.MethodData on all curative resections for Stages I–III colorectal cancer performed at a tertiary referral hospital in 2007–2010 were recorded in the Swedish Colorectal Cancer Registry and were matched to local databases for laboratory results and blood transfusion. Patients who died within 30 days or during primary hospital admission were excluded. Preoperative haemoglobin, CRP and albumin levels were recorded for 417 patients. A score (0–3) was derived on the presence of anaemia (Hb < 120 g/l for women and < 130 g/l for men), raised CRP (> 10 mg/ml) and low albumin (< 35 g/dl). The risks for recurrence and impaired overall survival were assessed using Cox regression analyses.ResultsImpaired overall survival was found when one, two or three of the criteria anaemia, elevated CRP and low albumin were present prior to surgery [hazard ratio (HR) 3.61, 95% CI 1.66–7.85; HR 3.91, 95% CI 1.75–8.74; HR 4.85, 95% CI 2.15–10.93, respectively]. The risk for recurrence, however, was not related to the presence of these criteria.ConclusionOverall survival after curative surgery for Stages I–III colorectal cancer is impaired when anaemia, elevated CRP or low albumin exist prior to surgery.