bluuebunny/crossref_metadata_2025_split huggingface dataset:
Augmented Case-Only Designs for Randomized Clinical Trials with Failure Time Endpoints
Authors: Dai James Y. , Zhang Xinyi Cindy , Wang Ching-Yun , Kooperberg Charles 
Published: September 2015

SummaryUnder suitable assumptions and by exploiting the independence between inherited genetic susceptibility and treatment assignment, the case-only design yields efficient estimates for subgroup treatment effects and gene-treatment interaction in a Cox model. However it cannot provide estimates of the genetic main effect and baseline hazards, that are necessary to compute the absolute disease risk. For two-arm, placebo-controlled trials with rare failure time endpoints, we consider augmenting the case-only design with random samples of controls from both arms, as in the classical case-cohort sampling scheme, or with a random sample of controls from the active treatment arm only. The latter design is motivated by vaccine trials for cost-effective use of resources and specimens so that host genetics and vaccine-induced immune responses can be studied simultaneously in a bigger set of participants. We show that these designs can identify all parameters in a Cox model and that the efficient case-only estimator can be incorporated in a two-step plug-in procedure. Results in simulations and a data example suggest that incorporating case-only estimators in the classical case-cohort design improves the precision of all estimated parameters; sampling controls only in the active treatment arm attains a similar level of efficiency.
Learning outside of classroom: Exploring the active part of an informal online English learning community in China
Authors: Sun Yanyan , Franklin Teresa , Gao Fei 
Published: September 2015

AbstractThis study explored how the GRE Analytical Writing Section Discussion Forum, an informal online language learning community in China, functioned to support its members to improve their English writing proficiency. The Community of Inquiry (CoI) model was used as the theoretical framework to explore the existence of teaching presence, cognitive presence and social presence in the GRE Analytical Writing Section Discussion Forum. The transcript analysis of postings in the GRE Analytical Writing Section Discussion Forum was used to find the existence of teaching, cognitive presence and social presence, and an adapted CoI survey was sent to members to measure their perceived teaching, cognitive and social presences. The results showed strong evidences of teaching presence, cognitive presence and social presence, and high levels of perceived teaching, cognitive and social presences in the GRE Analytical Writing Section Discussion Forum. The well‐designed technological environment, distributed teaching presence shared by moderators and members, and extensive evidences of social presence in the discussion forum worked together to support learning in the GRE Analytical Writing Section Discussion Forum.
The effectiveness of three serious games measuring generic learning features
Authors: Bakhuys Roozeboom Maartje , Visschedijk Gillian , Oprins Esther 
Published: September 2015

AbstractAlthough serious games are more and more used for learning goals, high‐quality empirical studies to prove the effectiveness of serious games are relatively scarce. In this paper, three empirical studies are presented that investigate the effectiveness of serious games as opposed to traditional classroom instruction on learning features as well as learning outcomes. All three studies used a similar longitudinal case‐control study design and measured the same set of learning features (control, challenge, feedback, engagement and social interaction). Learning outcomes were measured by self‐report and knowledge tests. Results of the three studies show that students that played the serious games scored higher on features associated with high‐quality learning. Furthermore, the studies show that serious gaming is more effective on self‐reported learning outcomes than traditional classroom instruction. Effects of serious gaming on the knowledge tests were not found. The studies serve as a first step to the development of a generic evaluation framework for serious gaming.
Effectiveness of collaborative learning with 3D virtual worlds
Authors: Cho Young Hoan , Lim Kenneth Y. T. 
Published: September 2015

AbstractVirtual worlds have affordances to enhance collaborative learning in authentic contexts. Despite the potential of collaborative learning with a virtual world, few studies investigated whether it is more effective in student achievements than teacher‐directed instruction. This study investigated the effectiveness of collaborative problem solving and collaborative observation using virtual worlds. Secondary school students (n = 101) participated in the study as part of their coursework in three geography classes. This study found that collaborative problem solving and observation were more effective in facilitating and maintaining intrinsic motivation than teacher‐directed instruction. Students in the collaborative observation condition outperformed those in the other conditions when it came to knowledge gains. Lastly, collaborative problem solving and observation were more beneficial for group performance than teacher‐directed instruction. These results were discussed in regard to the impacts of interactive learning and the cognitive load of using virtual worlds.
The role of emotion dysregulation in insomnia: Longitudinal findings from a large community sample
Authors: Jansson‐Fröjmark Markus , Norell‐Clarke Annika , Linton Steven J. 
Published: September 2015

ObjectivesThe purpose of this longitudinal investigation was to examine the association between emotion regulation and future insomnia (incidence and persistence).DesignA longitudinal study in the general population.MethodsA survey was sent out to 5,000 individuals in the community. To those who returned the baseline questionnaire (n = 2,333), two follow‐up surveys, 6 and 18 months later, were sent out and then completed by 1,887 and 1,795 individuals, respectively. The survey contained information about demographic factors, insomnia symptomatology, the Difficulties in Emotion Regulation Scale, anxiety, and depression.ResultsThe findings suggested that emotion regulation at baseline was not associated with the incidence or persistence of insomnia. Overall, the effect sizes were very small to medium. When examining changes in emotion regulation over time, a different pattern emerged. Partial support was established for the notion that decreases in emotion regulation were related to incident and persistent insomnia, as a decrease in emotion regulation was associated with a higher likelihood of future insomnia. Yet, the effect sizes were very small to small.ConclusionThis study does partly point towards a longitudinal association between emotion dysregulation and insomnia. This might have implications for the conceptualization and management of insomnia as well as for future research.
Statement of contribution

What is already known on this subject?

Previous research has indicated that emotion dysregulation might be enhanced in patients with insomnia.

A number of limitations have however hindered progress in understanding how emotion dysregulation is related to insomnia, such as limited research on the topic and relying solely on cross‐sectional data.

What does this study add?

The current investigation showed that emotion dysregulation is a risk factor for the development of incident and persistent insomnia.

This study also shows that increased emotion dysregulation over time heightens the risk of incident and persistent insomnia.
Are synesthetes exceptional beyond their synesthetic associations? A systematic comparison of creativity, personality, cognition, and mental imagery in synesthetes and controls
Authors: Chun Charlotte A. , Hupé Jean‐Michel 
Published: September 2015

Synesthesia has historically been linked with enhanced creativity, but this had never been demonstrated in a systematically recruited sample. The current study offers a broad examination of creativity, personality, cognition, and mental imagery in a small sample of systematically recruited synesthetes and controls (n = 65). Synesthetes scored higher on some measures of creativity, personality traits of absorption and openness, and cognitive abilities of verbal comprehension and mental imagery. The differences were smaller than those reported in the literature, indicating that previous studies may have overestimated group differences, perhaps due to biased recruitment procedures. Nonetheless, most of our results replicated literature findings, yielding two possibilities: (1) our study was influenced by similar biases, or (2) differences between synesthetes and controls, though modest, are robust across recruitment methods. The covariance among our measures warrants interpretation of these differences as a pattern of associations with synesthesia, leaving open the possibility that this pattern could be explained by differences on a single measured trait, or even a hidden, untested trait. More generally, this study highlights the difficulty of comparing groups of people in psychology, not to mention neuropsychology and neuroimaging studies. The requirements discussed here – systematic recruitment procedures, large battery of tests, and large cohorts – are best fulfilled through collaborative efforts and cumulative science.
Stable 18O and 13C isotope records of Viviparus diluvianus (Kunth, 1865) shells from Holsteinian (MIS 11) lakes of eastern Poland as palaeoenvironmental and palaeoclimatic proxies
Authors: Szymanek Marcin , Bińka Krzysztof , Nitychoruk Jerzy 
Published: September 2015

The oxygen and carbon stable isotope composition of Viviparus diluvianus shells was determined in the palaeolakes of the Holsteinian interglacial (MIS 11) in eastern Poland: the Ortel Królewski, Hrud, Ossówka, Roskosz and Szymanowo lakes. The occurrence of V. diluvianus covers the Taxus zone, the so‐called intra‐interglacial cooling period (Pinus‐Larix zone), the climatic optimum (Carpinus‐Abies zone) and the post‐optimal period with an undefined pollen zone. The isotope record of V. diluvianus shells allowed palaeoclimate and palaeoenvironmental reconstructions. δ18O and δ13C vary from −8.7‰ in the post‐optimal period to −4.8‰ in the optimal period, and from −10.6‰ at the beginning of the Taxus zone to −4.2‰ at the climatic optimum, respectively. A positive correlation of the isotope curves indicates closed‐water bodies, and only at Roskosz was some occasional overflow inferred. Higher oxygen isotopes correspond to an increase in temperature and/or enhanced evaporation, which is well marked in the Carpinus‐Abies zone, whereas samples enriched in 13C are correlated with periods demonstrating a lower water level and higher productivity in the lakes. Episodes of lake shallowing and dense aquatic vegetation occurred in the Pinus‐Larix zone and during the climatic optimum. The isotope ratios for the climatic optimum significantly exceed those of the other periods, thus pointing to warmer conditions. An estimation of relative changes of average summer temperatures using the δ18O/temperature gradient yielded variation of 1–2 °C within the lakes. Absolute temperature reconstructions indicate the effects of specific local conditions. Hence, V. diluvianus shells offer a reliable proxy in qualitative studies of interglacial lake records.
International migration and trade agreements: The new role of PTAs
Authors: Orefice Gianluca 
Published: September 2015

AbstractThis paper provides an empirical analysis of the relationship between preferential trade agreements (PTAs) and bilateral migration flows. Building on the empirical literature on the determinants of migration flows, I estimate a modified gravity model to assess the role of PTAs and their content on bilateral migration flows. Using a sample of 29 OECD destination countries over the period 1998–2008, I show a strong positive effect of PTAs on bilateral migration flows. I find that the content of PTAs also matters: when visa‐and‐asylum and labour market related provisions are included in PTAs, this further stimulates bilateral migration flows. Different estimation strategies, including instrumental variables, are employed to address the potential endogeneity bias problems related to PTAs and their content.
Foster carers' experiences of a paired reading literacy intervention with looked‐after children
Authors: Forsman Hilma 
Published: September 2015

AbstractPrevious studies have shown that paired reading, a structured literacy intervention, is a promising method for improving looked‐after children's literacy skills. The aim of this study was to explore variations in foster carers' experiences of conducting the intervention. Interviews were carried out with 15 Swedish foster carers with varying experiences in programme compliance and of practicing the method. Findings suggest that the intervention process starts with getting carers involved, which seems to be dependent on a positive carer attitude. Integrating the reading training in the everyday life is another important aspect, which evolves around motivating the child and prioritizing the reading sessions. Furthermore, the results emphasize the need of having a flexible approach when delivering the intervention. The results suggest that it is possible to engage foster carers in literacy training for looked‐after children and that paired reading can provide a model for competent reading and also result in improved child/carer relations. However, participants need support, and in some cases adjustments in the day‐to‐day delivery of the intervention are required.
British Rhinological Society 14th Annual Meeting The Central Convention Centre, Manchester. 15th May 2015
Authors: Hayes S. , Pender S. , Salib R. , Harries P. 
Published: September 2015

ObjectivesChronic rhinosinusitis (CRS) is a common condition with 20% of patients developing nasal polyps (NP). Bacterial biofilms have been implicated as mediators of the inflammatory reaction in CRS; however, little data pertains to bacterial profiles in NP. Therefore, we conducted a preliminary study characterising bacterial profiles in NP.MethodsA prospective study was conducted in nine patients with CRS with nasal polyps (CRSwNP) undergoing endoscopic sinus surgery and five control patients undergoing trans−sphenoidal pituitary surgery. Non−polypoidal sinonasal mucosa and NPs were collected from each CRSwNP patient, and sinonasal mucosa, from controls. The bacterial profiles were assessed using fluorescence in situ hybridisation, confocal laser scanning microscopy (CLSM) and immunohistochemistry.ResultsCLSM demonstrated surface−related bacterial biofilms on all samples of non−polypoidal sinonasal mucosa, but not on the epithelial surface of NP. However, subepithelial and intracellular bacteria were observed within host cells in all NP samples. No biofilms or intracellular bacteria were observed in control samples. Intracellular bacteria were identified as S. aureus. Immunohistochemical colocalisation identified mast cells (MC) as the S. aureus−harbouring host cells.ConclusionThe observation of intracellular S. aureus is a novel finding and may have relevance to the pathogenesis of NP. Furthermore, S. aureus internalisation within MC potentially allows the establishment of a niche of viable intracellular bacterial reservoirs protected from extracellular antimicrobial compounds and with the ability to constantly seed bacteria thus sustaining the inflammatory reaction and leading to chronicity.
Dermatopathologic manifestations of intravenous drug use
Authors: Tse Julie Y. , Adisa Morayo , Goldberg Lynne J. , Nazarian Rosalynn M. 
Published: September 2015

BackgroundThe rate of intravenous drug use (IVDU) has been increasing nationally; however, cutaneous manifestations of IVDU have infrequently been investigated. We report a series of the clinicopathological correlation of IVDU in the skin.MethodsA search of surgical pathology files between the years 2000 and 2014 was performed for cutaneous specimens from patients with a reported history of IVDU for which the histopathological findings could not be attributed to another etiology. Ten cases for which slides were available were included in the study.ResultsPatients had an average age of 39.7 years and had active or recent history of IVDU. Clinical impressions included ulcer, granulomatous dermatitis, vasculitis, pyoderma gangrenosum and hyperpigmentation at injection sites. Histopathology revealed leukocytoclastic vasculitis (n = 2), dermal pigment deposition (n = 3), non‐specific ulceration/scarring (n = 4) and necrobiosis lipoidica‐like dermatitis (n = 1). No infectious etiology or polarizable foreign material was identified in any case.ConclusionsCutaneous manifestations of IVDU should be considered in the differential as an etiology for dermatopathologic findings in high‐risk patients. We report histopathological findings beyond the scope of those most commonly associated with IVDU. We aim to raise awareness of the cutaneous manifestations of IVDU to improve clinicopathological correlation and patient management in light of the ongoing epidemic.
Novel 3D‐printing technique for caps to enable tailored therapeutic endoscopy
Authors: Ko Weon Jin , Song Ga Won , Hong Sung Pyo , Kwon Chang‐il , Hahm Ki Baik , Cho Joo Young 
Published: September 2015

Background and AimTo evaluate the feasibility of a tailored endoscopic cap created using 3D‐printing technology that is customized according to esophagogastric lesions of each patient.MethodsTailored endoscopic caps, which were designed and fabricated with a 3D printer, were inserted in 35 patients. The types of cap were side‐hole cap made for cap‐assisted endoscopic mucosal resection (EMRC), oblique‐head cap designed for endoscopic submucosal dissection (ESD), wide‐head cap used for Trucut biopsy (TCB), and narrow‐tip cap to facilitate peroral endoscopic myotomy (POEM).ResultsEMRC in the esophagus and gastroesophageal junction was carried out using a side‐hole cap in seven patients. Median total procedure time for successful removal of lesions was 14 min (range 8–50 min). Gastric ESD was carried out using with an oblique‐head cap in 16 patients, for which the median total procedure time was 53 min. TCB in the esophagus was done using a wide‐head cap in eight patients. While carrying out POEM for tunneling, a narrow‐tip cap was used in four patients with achalasia.ConclusionBased on the current proof‐of‐concept study, we anticipate that creating a tailored endoscopic cap is feasible for therapeutic endoscopy.
The Challenges of Research Informed Consent in Socio‐Economically Vulnerable Populations: A Viewpoint From the Democratic Republic of Congo
Authors: Kalabuanga Marion , Ravinetto Raffaella , Maketa Vivi , Muhindo Mavoko Hypolite , Fungula Blaise , Inocêncio da Luz Raquel , Van Geertruyden Jean‐Pierre , Lutumba Pascal 
Published: September 2015

AbstractIn medical research, the ethical principle of respect for persons is operationalized into the process of informed consent. The consent tools should be contextualized and adapted to the different socio‐cultural environment, especially when research crosses the traditional boundaries and reaches poor communities. We look at the challenges experienced in the malaria Quinact trial, conducted in the Democratic Republic of Congo, and describe some lessons learned, related to the definition of acceptable representative, the role of independent witness and the impact of socio‐economic vulnerability.To ensure children's protection, consent is required by the parents or, in their absence, by a legally mandated representative. In our setting, children's responsibility is often entrusted permanently or temporarily to relatives or friends without a tribunal mandate. Hence, a notion of ‘culturally acceptable representative’ under supervision of the local Ethics Committee may be more suitable.To ensure protection of illiterate subjects, an independent witness is required to confirm that the consent was freely given. However, in low‐literacy contexts, potential witnesses often don't have any previous relationship with patient and there may be power‐unbalance in their relationship, rather than genuine dialogue.In poor communities, trial participation may be seen as an opportunity to secure access to healthcare. Poverty may also lead to ‘competition’ to access the research‐related benefits, with a risk of disturbance at societal or household level.Adjusting consent procedures to sociocultural and socioeconomic realities is essential for fulfilling the underlying ethical principles. This requires a collaborative dialogue between researchers, regulators and ethics committees.
Effects of microclimate on soil bacterial communities across two contrasting timberline ecotones in southeast Tibet
Authors: Yuan Y. L. , Si G. C. , Wang J. , Han C. H. , Zhang G. X. 
Published: September 2015

SummaryThe Sergyemla Mountains have unique timberline patterns. Abies georgei var. smithii (Viguie & Gaussen) and Juniperus saltuaria (Rehder & E. H. Wilson) dominate the north‐facing and south‐facing slopes of a U‐shaped valley, respectively. Although these two timberlines represent the world's highest natural tree lines, little is known about the structure of their soil bacterial communities and the factors that control them. To characterize and compare the soil bacterial communities of two timberline ecotones with different spatial orientations, we investigated their structures by terminal restriction fragment length polymorphism analysis and sequencing methods. We found that the structures of the soil bacterial communities differed significantly between the two opposite slopes, and the difference between the bacterial communities correlated primarily with soil carbon:nitrogen ratios. This probably relates to differences in the microclimate (mean soil temperature) between the two aspects in the world's highest timberline ecotones. In addition, the structures of soil bacterial communities also differed significantly with soil depth, and total nitrogen content had the greatest effect on the bacterial communities. In this region, soil temperature rather than mean annual precipitation has a major effect on the structures of soil bacterial communities. Microclimate differences (mainly differences in soil temperature) between the two opposite slopes might indicate that an amplitude increase of 2°C in soil temperature could change the structures of soil bacterial communities by changing the status of soil carbon and nitrogen in these timberline ecotones.