bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Pairwise Likelihood Augmented Cox Estimator for Left-truncated Data
Authors: Wu Fan , Kim Sehee , Qin Jing , Saran Rajiv , Li Yi 
Published: August 2017

SummarySurvival data collected from a prevalent cohort are subject to left truncation and the analysis is challenging. Conditional approaches for left-truncated data could be inefficient as they ignore the information in the marginal likelihood of the truncation times. Length-biased sampling methods may improve the estimation efficiency but only when the underlying truncation time is uniform; otherwise, they may generate biased estimates. We propose a semiparametric method for left-truncated data under the Cox model with no parametric distributional assumption about the truncation times. Our approach is to make inference based on the conditional likelihood augmented with a pairwise likelihood, which eliminates the truncation distribution, yet retains the information about the regression coefficients and the baseline hazard function in the marginal likelihood. An iterative algorithm is provided to solve for the regression coefficients and the baseline hazard function simultaneously. By empirical process and U-process theories, it has been shown that the proposed estimator is consistent and asymptotically normal with a closed-form consistent variance estimator. Simulation studies show substantial efficiency gain of our estimator in both the regression coefficients and the cumulative baseline hazard function over the conditional approach estimator. When the uniform truncation assumption holds, our estimator enjoys smaller biases and efficiency comparable to that of the full maximum likelihood estimator. An application to the analysis of a chronic kidney disease cohort study illustrates the utility of the method.
Understanding tamoxifen adherence in women with breast cancer: A qualitative study
Authors: Moon Zoe , Moss‐Morris Rona , Hunter Myra S. , Hughes Lyndsay D. 
Published: August 2017

ObjectiveNon‐adherence to tamoxifen is common in breast cancer survivors and is associated with poor clinical outcomes. This study aimed to understand womens' experiences of taking tamoxifen and to identify factors which may be associated with non‐adherence.DesignA qualitative study using semi‐structured interviews.MethodsThirty‐two breast cancer survivors who had been prescribed tamoxifen took part in interviews conducted face to face or over the telephone. They were transcribed verbatim and analysed using inductive thematic analysis with elements of grounded theory.ResultsA key theme identified in the data was weighing up costs and benefits of treatment, which resulted in women falling into three groups; tamoxifen is keeping me alive, tamoxifen is not worth the reduced risk of recurrence, or conflicting beliefs about the harms and benefits of treatment. Additional themes were living with risk of recurrence and information & support.ConclusionsWomen who believed that the necessity of tamoxifen outweighed its costs were more likely to be adherent, whereas women who thought that the benefits did not outweigh the side effects were more likely to have discontinued. A third more ambivalent group believed strongly in the importance of treatment, but were struggling with side effects and were often non‐adherent. Patients sometimes felt unsupported and discussed a need for more comprehensive information. To increase adherence, future research needs to explore ways to increase beliefs around tamoxifen necessity and how to help women cope with side effects.
Statement of contribution

What is already known on this subject?

Non‐adherence to tamoxifen is associated with increased risk of recurrence and mortality.

Up to 50% of patients are non‐adherent to tamoxifen by the fifth year of treatment

Few consistent predictors of tamoxifen non‐adherence have been identified.

What does this study add?

Many women report not knowing how to manage their side effects.

Non‐adherence is related to how women weigh up their side effects against their medication beliefs.

Interventions aiming to increase necessity beliefs and improve symptom management may be effective.
Tumor endothelial cells with high aldehyde dehydrogenase activity show drug resistance
Authors: Hida Kyoko , Maishi Nako , Akiyama Kosuke , Ohmura‐Kakutani Hitomi , Torii Chisaho , Ohga Noritaka , Osawa Takahiro , Kikuchi Hiroshi , Morimoto Hirofumi , Morimoto Masahiro , Shindoh Masanobu , Shinohara Nobuo , Hida Yasuhiro 
Published: August 2017

Tumor blood vessels play an important role in tumor progression and metastasis. We previously reported that tumor endothelial cells (TEC) exhibit several altered phenotypes compared with normal endothelial cells (NEC). For example, TEC have chromosomal abnormalities and are resistant to several anticancer drugs. Furthermore, TEC contain stem cell‐like populations with high aldehyde dehydrogenase (ALDH) activity (ALDHhigh TEC). ALDHhigh TEC have proangiogenic properties compared with ALDHlow TEC. However, the association between ALDHhigh TEC and drug resistance remains unclear. In the present study, we found that ALDH mRNA expression and activity were higher in both human and mouse TEC than in NEC. Human NEC:human microvascular endothelial cells (HMVEC) were treated with tumor‐conditioned medium (tumor CM). The ALDHhigh population increased along with upregulation of stem‐related genes such as multidrug resistance 1, CD90, ALP, and Oct‐4. Tumor CM also induced sphere‐forming ability in HMVEC. Platelet‐derived growth factor (PDGF)‐A in tumor CM was shown to induce ALDH expression in HMVEC. Finally, ALDHhigh TEC were resistant to fluorouracil (5‐FU) in vitro and in vivo. ALDHhigh TEC showed a higher grade of aneuploidy compared with that in ALDHlow TEC. These results suggested that tumor‐secreting factor increases ALDHhigh TEC populations that are resistant to 5‐FU. Therefore, ALDHhigh TEC in tumor blood vessels might be an important target to overcome or prevent drug resistance.
Clear Self, Better Relationships: Adolescents’ Self‐Concept Clarity and Relationship Quality With Parents and Peers Across 5 Years
Authors: Becht Andrik I. , Nelemans Stefanie A. , van Dijk Marloes P. A. , Branje Susan J. T. , Van Lier Pol A. C. , Denissen Jaap J. A. , Meeus Wim H. J. 
Published: August 2017

This study examined reciprocal associations between adolescents’ self‐concept clarity (SCC) and their relationship quality with parents and best friends in a five‐wave longitudinal study from age 13 to 18 years. In all, 497 adolescents (57% boys) reported on their SCC and all informants (i.e., adolescents, both parents, and adolescents’ best friends) reported on support and negative interaction. Within‐person cross‐lagged analyses provided systematic evidence for both parent effects and child effects, with the direction of effects being strongly dependent on the relational context. For example, higher maternal support predicted higher adolescent SCC, supporting a parent effects perspective, whereas higher SCC predicted lower paternal negative interaction, supporting a child effects perspective. Peer effects on adolescent SCC were not consistently found across adolescent and best friend reports.
Shark Bites and Shark Conservation: An Analysis of Human Attitudes Following Shark Bite Incidents in Two Locations in Australia
Authors: Pepin‐Neff Christopher , Wynter Thomas 
Published: August 2017

AbstractThis article reports on the first comparative surveys in two separate locations to measure public attitudes toward sharks following shark bite incidents. This study focuses directly on the communities affected by the shark bites, both in Australia—the town of Ballina in the State of New South Wales (N = 500) and the city of Perth in Western Australia (N = 600)—and reports on their attitudes and policy preferences relating to sharks immediately after serious shark bite incidents in 2015 and 2016. In both communities we find that a large majority of respondents prefer nonlethal policies; most respondents believe shark bite incidents to be accidental rather than intentional; while fear of sharks correlates with support for lethal policies, this association is powerfully mediated by perceptions of intentionality. These findings have implications for international wildlife management, particularly regarding predator species in need of conservation. Conservation is based on the public acceptability of a species and if intentionality can mediate fear effects and promote policies that protect the species this is a step forward for conservation management globally.
Relationship of cardiac troponin to systolic global longitudinal strain in hypertrophic cardiomyopathy
Authors: Agarwal Anushree , Yousefzai Rayan , Shetabi Kambiz , Samad Fatima , Aggarwal Saurabh , Cho Chi , Bush Michelle , Jan M. Fuad , Khandheria Bijoy K. , Paterick Timothy E. , Tajik A. Jamil 
Published: August 2017

BackgroundA high proportion of stable hypertrophic cardiomyopathy (HCM) patients have elevated serum cardiac troponin I (cTnI), but its clinical and echocardiographic determinants are unknown. Our objective was to determine the prevalence and clinical predictors of positive troponin (cTnI+) in a well‐defined population of HCM patients using a highly sensitive assay.MethodsWe retrospectively interrogated medical records of 167 stable HCM patients from 1/2011 to 3/2014. cTnI >0.04 ng/mL was considered positive.ResultsThirty‐four percent were troponin‐positive (median cTnI was 0.1 [0.07, 0.2] ng/dL). cTnI as a continuous variable correlated positively with maximal left ventricular wall thickness (LVT), maximal interventricular septal thickness, and global longitudinal strain (GLS) (P<.001). Unadjusted OR (95% CI) for positive troponin was 0.5 (0.3–0.9, P=.05) for obstructive HCM, 3.2 (1.7–5.9, P<.0001) for increased LVT, 0.3 (0.2–0.6, P<.0001) for −5% increase in GLS, 0.2 (0.04–0.9, P=.04) for moderate‐to‐severe mitral regurgitation, and 1.9 (0.9–3.9, P=.06) for implantable cardioverter defibrillator history. After adjusting for these variables, only maximum LVT (OR 2.5 [95% CI: 1.1–5.7, P=.02]) and GLS (OR 0.3 [95% CI: 0.2–0.6, P=.001]) were independent predictors. The percentage of patients with a positive cTnI increased from 19% to 24% and 57% across tertiles of LVT (P=.003) and decreased from 54% to 33% and 14% across tertiles of GLS (P<.0001).ConclusionIn this cohort of HCM patients, the association of reduced GLS and positive troponin was independent of LVT. Further studies are warranted to evaluate whether their combination adds prognostic value in identifying high‐risk patients to define effective and early intervention strategies.
Sex, life history and morphology drive individual variation in flight performance of an insect parasitoid
Authors: FISCHBEIN DEBORAH , VILLACIDE JOSÉ M. , DE LA VEGA GERARDO , CORLEY JUAN C. 
Published: August 2017

1. The movement of organisms can be driven by multiple factors and has implications for fitness and the spatial distribution of populations. Insects spend a large proportion of their adult lives foraging by flying for resources; however, their capability and motivation to move can vary across individuals.2. The aims of this study were to examine interindividual and sex differences in flight performance and flight characteristics, using a flight mill bioassay, in Megarhyssa nortoni (Hymenoptera; Ichneumonidae), a parasitoid of the invasive woodwasp Sirex noctilio (Hymenoptera: Siricidae), one of the most important pests of pine afforestation worldwide. We also assessed the influence of morphological traits in combination with sex on flight and explored the cost of flight on longevity and mass loss.3. The results show a difference between sexes in flight characteristics and performance. Females show greater total distance flown than males, and have a better capacity to undergo sustained flight. Sexual size dimorphism was also found and it was noted that size positively affects distances travelled. Females have a longer life span than males, yet no differences were noted in longevity within sex between individuals that did not fly and those that flew. Age did not influence flight performance of females or impacted on post‐flight longevity. Females lost less body mass than males even after flying longer distances.4. These results suggest that sex‐specific behaviours probably govern flight abilities together with (and not only because of) morphological traits. The paper discusses sex‐specific life‐history strategies in parasitoids and their implications for biocontrol programmes.
Metabolic compensation constrains the temperature dependence of gross primary production
Authors: Padfield Daniel , Lowe Chris , Buckling Angus , Ffrench‐Constant Richard ,   Student Research Team, Jennings Simon , Shelley Felicity , Ólafsson Jón S. , Yvon‐Durocher Gabriel 
Published: August 2017

AbstractGross primary production (GPP) is the largest flux in the carbon cycle, yet its response to global warming is highly uncertain. The temperature dependence of GPP is directly linked to photosynthetic physiology, but the response of GPP to warming over longer timescales could also be shaped by ecological and evolutionary processes that drive variation in community structure and functional trait distributions. Here, we show that selection on photosynthetic traits within and across taxa dampens the effects of temperature on GPP across a catchment of geothermally heated streams. Autotrophs from cold streams had higher photosynthetic rates and after accounting for differences in biomass among sites, biomass‐specific GPP was independent of temperature in spite of a 20 °C thermal gradient. Our results suggest that temperature compensation of photosynthetic rates constrains the long‐term temperature dependence of GPP, and highlights the importance of considering physiological, ecological and evolutionary mechanisms when predicting how ecosystem‐level processes respond to warming.
Extraction of 22 equine cheek teeth with displaced sagittal fractures using polymethylmethacrylate stabilisation (2011–2016)
Authors: Pearce D. J. , Brown J. A. 
Published: August 2017

SummaryDisplaced sagittal cheek tooth fractures are a cause of oral pain, quidding and apical infection. Intraoral extraction is the preferred technique to remove affected teeth, but can be difficult due to displaced and friable fracture fragments. Stabilising fracture fragments via filling of the fracture space with polymethymethacrylate (PMMA) prior to removal may be a useful method to facilitate intraoral extraction. Case details were examined retrospectively. A total of 22 cheek teeth required extraction in 20 horses because of displaced sagittal fractures. Clinical diagnoses were made using oral examination, oral endoscopy, skull radiography and computed tomography. All procedures were performed in standing, sedated horses in stocks. Fracture spaces were cleaned and packed with PMMA and teeth removed using a routine intraoral extraction technique. Digital photographs of extracted teeth were taken and tooth measurements calibrated using digital image software. Intraoperative difficulties, as well as post‐operative complications were recorded. A total of 21 maxillary and one mandibular cheek teeth were extracted. All maxillary teeth had advanced infundibular caries. Intraoral extraction was successful in 16 cases; six were unsuccessful and required repulsion due to tooth fragmentation or abnormal dental anatomy. In 11 cases, maxillary or conchofrontal sinus trephination was performed to either treat sinusitis, repulse the tooth, or both. Two horses developed short‐term complications following local anaesthesia of the maxillary nerve. The mean ratio of fracture depth to tooth length was 0.59 and mean ratio of fracture width to tooth width 0.53. The limitations of the study are its small sample size, retrospective nature and lack of control group to compare extraction success in PMMA and non‐PMMA groups. It was concluded that using PMMA to stabilise displaced sagittal fractures in equine cheek teeth is a simple, effective method of facilitating intraoral extraction and may reduce the need for more invasive procedures.
Strontium‐90 plesiotherapy in the horse
Authors: Hollis A. R. 
Published: August 2017

SummaryStrontium‐90 plesiotherapy is a form of very superficial radiotherapy that is most commonly used as part of the management of ocular and periocular squamous cell carcinomas in the horse. Although it can be an extremely effective treatment, with the ability to deliver very high doses of radiation to the tumour without affecting the surrounding tissues, the penetration is only a few millimetres, which limits its use in equine medicine to very specific situations. In addition, the availability of strontium‐90 plesiotherapy is limited to specialist institutions due to the health and safety and security concerns of accessing a high activity sealed source.
Effect of electroslag remelting on the VHCF response of an AISI H13 steel
Authors: Tridello A. , Paolino D.S. , Chiandussi G. , Rossetto M. 
Published: August 2017

AbstractExperimental results have shown that high‐strength steels can fail in the Very‐High‐Cycle Fatigue (VHCF) regime with cracks originating from internal defects. Material cleanliness thus plays a major role in the VHCF response of high‐strength steels and refinement processes (eg, electroslag remelting [ESR] and vacuum arc remelting) could significantly enhance their performance.The present paper aims at investigating the effect of the ESR process on the VHCF behavior of an AISI H13 steel by carrying out fully reversed ultrasonic tension‐compression tests on hourglass specimens manufactured with and without the ESR process. Size effect is also taken into account in the paper: the effectiveness in the prediction of the VHCF response of specimens with large risk‐volumes from experimental data on specimens with small risk‐volumes is discussed and experimentally validated.
Lipidomics of the sea sponge Amphimedon queenslandica and implication for biomarker geochemistry
Authors: Gold D. A. , O'Reilly S. S. , Watson J. , Degnan B. M. , Degnan S. M. , Krömer J. O. , Summons R. E. 
Published: August 2017

AbstractDemosponges are a rich natural source of unusual lipids, some of which are of interest as geochemical biomarkers. Although demosponges are animals, they often host dense communities of microbial symbionts, and it is therefore unclear which lipids can be synthesized by the animal de novo, and which require input from the microbial community. To address this uncertainty, we analyzed the lipids of Amphimdeon queenslandica, the only demosponge with a published genome. We correlated the genetic and lipid repertoires of A. queenslandica to identify which biomarkers could potentially be synthesized and/or modified by the sponge. The fatty acid profile of A. queenslandica is dominated by an unusual Δ5,9 fatty acid (cis‐5,9‐hexacosadienoic acid)—similar to what has been found in other members of the Amphimdeon genus—while the sterol profile is dominated by C27‐C29 derivatives of cholesterol. Based on our analysis of the A. queenslandica genome, we predict that this sponge can synthesize sterols de novo, but it lacks critical genes necessary to synthesize basic saturated and unsaturated fatty acids. However, it does appear to have the genes necessary to modify simpler products into a more complex “algal‐like” assemblage of unsaturated fatty acids. Ultimately, our results provide additional support for the poriferan affinity of 24‐isopropylcholestanes in Neoproterozoic‐age rocks (the “sponge biomarker” hypothesis) and suggest that some algal proxies in the geochemical record could also have animal contributions.
Leap frog in slow motion: Divergent responses of tree species and life stages to climatic warming in Great Basin subalpine forests
Authors: Smithers Brian V. , North Malcolm P. , Millar Constance I. , Latimer Andrew M. 
Published: August 2017

AbstractIn response to climate warming, subalpine treelines are expected to move up in elevation since treelines are generally controlled by growing season temperature. Where treeline is advancing, dispersal differences and early life stage environmental tolerances are likely to affect how species expand their ranges. Species with an establishment advantage will colonize newly available habitat first, potentially excluding species that have slower establishment rates. Using a network of plots across five mountain ranges, we described patterns of upslope elevational range shift for the two dominant Great Basin subalpine species, limber pine and Great Basin bristlecone pine. We found that the Great Basin treeline for these species is expanding upslope with a mean vertical elevation shift of 19.1 m since 1950, which is lower than what we might expect based on temperature increases alone. The largest advances were on limber pine‐dominated granitic soils, on west aspects, and at lower latitudes. Bristlecone pine juveniles establishing above treeline share some environmental associations with bristlecone adults. Limber pine above‐treeline juveniles, in contrast, are prevalent across environmental conditions and share few environmental associations with limber pine adults. Strikingly, limber pine is establishing above treeline throughout the region without regard to site characteristic such as soil type, slope, aspect, or soil texture. Although limber pine is often rare at treeline where it coexists with bristlecone pine, limber pine juveniles dominate above treeline even on calcareous soils that are core bristlecone pine habitat. Limber pine is successfully “leap‐frogging” over bristlecone pine, probably because of its strong dispersal advantage and broader tolerances for establishment. This early‐stage dominance indicates the potential for the species composition of treeline to change in response to climate change. More broadly, it shows how species differences in dispersal and establishment may result in future communities with very different specific composition.
Sourcing from Africa: A Systematic Review and a Research Agenda
Authors: Kauppi Katri , Salmi Asta , You Weimu 
Published: August 2017

AbstractThe African continent is rapidly growing its global economic impact and becoming a more attractive sourcing context. However, very little is known about current purchasing practices, successes and challenges on this continent. The authors investigate the specific features that characterize supply management in Africa by conducting a systematic review of the literature on sourcing in and from Africa. Their aim is to help scholars direct their future research efforts. The authors take a thematic approach in their analysis of 57 articles, and identify key findings, research challenges and opportunities. They focus on four areas previously identified as distinguishing the sourcing context in Africa: African culture and ethics; the role of African countries and suppliers in global value chains; an increasing emphasis on sustainability; and the gradual development of professional procurement practices. It is found that research in the area of supply management in the African context is still scattered, with an evident need for more theoretically rich and methodologically rigorous inquiry. The authors propose a structured, theoretically grounded research agenda for each of the themes identified, and make general observations on potential future directions.