bluuebunny/crossref_metadata_2025_split huggingface dataset:
A cost‐effective analysis of fibrin sealants versus no sealant following open right hemihepatectomy for colorectal liver metastases
Authors: Pandanaboyana Sanjay , Bell Richard , Shah Nehal , Lodge J. Peter A. , Hidalgo Ernest , Toogood Giles J. , Prasad K. Raj 
Published: December 2014

AbstractBackgroundThere is paucity of data regarding the cost‐effectiveness of fibrin sealants during liver surgery. This study aimed to assess the cost‐effectiveness of fibrin sealants following right hemihepatectomy for colorectal liver metastases.MethodA prospectively maintained database between 2004 and 2013 was reviewed to identify patients who underwent a right hemihepatectomy with and without fibrin sealant application. Perioperative and post‐operative outcomes were analysed to assess its cost‐effectiveness.ResultsOne hundred and sixty‐three right hemihepatectomies were performed, of which 79 were in the fibrin sealant treatment group and 84 were in the no sealant group. No difference was seen between fibrin sealant and no sealant with regard to bile leak (P = 0.366), intra‐abdominal collections (P = 0.200) and overall post‐operative complications (P = 0.480). Operating costs were significantly cheaper in the no sealant group (P = 0.010). There was no difference seen in median post‐operative stay between fibrin sealant versus no treatment (8 versus 9 days, P = 0.327), median total bed cost (£3900 versus £4300, P = 0.400), mean transfusion cost per patient (P = 0.201) and overall cost (£6706.15 versus £6555.80, P = 0.792).ConclusionFibrin sealant application to cut surface during liver surgery confers no cost benefit and their routine use may not be recommended.
Trainee underperformance: a guide to achieving resolution
Authors: Rashid Prem , Grills Richard , Kuan Melvyn , Klein Deborah 
Published: December 2014

AbstractBackgroundUnderperformance and the disharmony it can cause are not commonly faced by trainees. However, when it occurs, a process to recognize and manage the issues compassionately must be put in place.MethodA literature review was undertaken to outline processes and themes in addressing and resolving these types of issues. A PubMed search using ‘surgical underperformance’ and ‘remedial teaching’ was used as a broad template to find papers that illustrated key concepts. One thousand four hundred and fifteen papers were identified. In papers where the titles were in line with the stated topic, 294 abstracts were reviewed. Key papers were used to develop themes. Additional cross‐referenced papers were also included where relevant.ResultsThere can be a variety of reasons for trainee underperformance. The root cause is not always clear. Disharmony can result in a surgical unit during this time. The involved trainee as well as the members of the clinical unit may experience a variety of stressors. A systematic process of management can be used to evaluate the situation and bring some resolution to difficulties in working relationships.ConclusionEarly constructive intervention improves outcomes. There should be a process to systematically and compassionately resolve underlying issues. This paper outlines the disharmony that can result from trainee underperformance and offers guidance for resolution to those involved.
Sleep in cluster headache − beyond a temporal rapid eye movement relationship?
Authors: Barloese M. C. J. , Jennum P. J. , Lund N. T. , Jensen R. H. 
Published: December 2014

Background and purposeCluster headache (CH) is a primary headache disorder characterized by severe attacks of unilateral pain following a chronobiological pattern. There is a close connection with sleep as most attacks occur during sleep. Hypothalamic involvement and a particular association with rapid eye movement (REM) sleep have been suggested. Sleep in a large, well‐characterized population of CH patients was investigated.MethodsPolysomnography (PSG) was performed on two nights in 40 CH patients during active bout and one night in 25 age, sex and body mass index matched controls in hospital. Macrostructure and other features of sleep were analyzed and related to phenotype. Clinical headache characterization was obtained by semi‐structured interview.ResultsNinety‐nine nights of PSG were analyzed. Findings included a reduced percentage of REM sleep (17.3% vs. 23.0%, P = 0.0037), longer REM latency (2.0 vs. 1.2 h, P = 0.0012) and fewer arousals (7.34 vs. 14.1, P = 0.003) in CH patients. There was no difference in prevalence of sleep apnea between patients (38%) and matched controls (32%, P = 0.64) although the apnea index in patients was numerically higher (mean apnea−hypopnea index 10.75 vs. 4.93). No temporal association between nocturnal attacks (n = 45) and particular sleep stages was observed.ConclusionsTo date, this is the largest study of sleep in CH. It is demonstrated that REM sleep is affected which is in line with our current understanding of CH and hypothalamic involvement in the regulation of this sleep stage. Further, fewer arousals were found in CH patients but no association between apnea events or specific sleep stages. The findings support a central role of the hypothalamus and arousal systems in CH.
Clinical treatment and prognosis of equine odontoclastic tooth resorption and hypercementosis
Authors: Lorello O. , Foster D. L. , Levine D. G. , Boyle A. , Engiles J. , Orsini J. A. 
Published: December 2014

SummaryReasons for performing studyEquine odontoclastic tooth resorption and hypercementosis is an infrequent and underdiagnosed form of severe dental disease in horses that can affect quality of life. The study was performed to compare the clinical, radiographic, histological and prognostic findings specific to equine odontoclastic tooth resorption and hypercementosis in horses. Removal of affected teeth is currently the best treatment.ObjectivesThe goals are to report salient clinical and histological features of the disease and its management in a case series describing an under‐reported syndrome in horses and the long‐term prognosis.Study designRetrospective case series.MethodsMedical records from New Bolton Center, University of Pennsylvania from January 2000 to December 2012 were reviewed from horses that had a diagnosis of ‘cementoma’ or ‘hypercementosis’ and any associated dental‐related diagnosis affecting the teeth and oral cavity. Radiographic, surgical and histological reports were collated and the clinical cases compared and tabulated to provide a better description of the equine disease.ResultsA total of 18 cases were identified, 17 of which were geldings and one of which was a nonbreeding stallion; no mares had the disease. The mean age at diagnosis was 24 years, with a range of 17–29 years. There was no breed predilection, and varied clinical signs relating to the mouth were found. Some teeth involved had only radiographic changes of disease and not gross clinical evidence. The mandibular incisors were generally affected earlier than the maxillary incisors, but the disease is progressive, and eventually, all of the incisors and sometimes the canines are involved. No premolars or molars were affected in this case series.ConclusionsBased on this case series, all teeth, and particularly the incisors, should be examined for signs of gingivitis and hypercementosis and subsequently radiographed for an early diagnosis and management. When compared with our hospital population, older geldings were more likely to be affected with cementoma formation and its accompanying resorptive process. Removal of clinically and radiographically affected teeth carries a good prognosis for improved quality of life.
Extensive metazoan reefs from the Ediacaran Nama Group, Namibia: the rise of benthic suspension feeding
Authors: Wood R. , Curtis A. 
Published: December 2014

AbstractWe describe new, ecologically complex reef types from the Ediacaran Nama Group, Namibia, dated at ~548 million years ago (Ma), where the earliest known skeletal metazoans,Cloudina riemkeaeandNamacalathus, formed extensive reefs up to 20 m in height and width.C. riemkeaeformed densely aggregating assemblages associated with microbialite and thrombolite, each from 30 to 100 mm high, which successively colonised former generations to create stacked laminar or columnar reef frameworks.C. riemkeaeindividuals show budding, multiple, radiating attachment sites and cementation between individuals. IsolatedNamacalathuseither intergrew withC. riemkeaeor formed dense, monospecific aggregations succeedingC. riemkeaeframeworks, providing a potential example of environmentally mediated ecological succession.CloudinaandNamacalathusalso grow cryptically, either as pendent aggregations from laminar crypt ceilings in microbial framework reefs or as clusters associated with thrombolite attached to neptunian dyke walls. These reefs are notable for their size, exceeding that of the succeeding Lower Cambrian archaeocyath–microbial communities. The repeated colonisation shown byC. riemkeaeof former assemblages implies philopatric larval aggregation to colonise limited favourable substrates. As such, not only were skeletal metazoans more important contributors to reef building in the Ediacaran, but there were also more variable reef types with more complex ecologies, than previously thought. Such an abundance of inferred suspension feeders with biomineralised skeletons indicates the efficient exploitation of new resources, more active carbon removal with a strengthened energy flow between planktic and benthic realms, and the rise of biological control over benthic carbonate production. These mark the prelude to the Cambrian Explosion and the modernisation of the global carbon cycle.
Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake
Authors: Sweet Shannan K. , Griffin Kevin L. , Steltzer Heidi , Gough Laura , Boelman Natalie T. 
Published: December 2014

AbstractSatellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub‐dominated and evergreen/graminoid‐dominated community‐level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant‐community‐specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra‐specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10‐day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake.
The abiotic and biotic factors limiting establishment of predatory fishes at their expanding northern range boundaries in Ontario, Canada
Authors: Alofs Karen M. , Jackson Donald A. 
Published: December 2014

AbstractThere is a poor understanding of the importance of biotic interactions in determining species distributions with climate change. Theory from invasion biology suggests that the success of species introductions outside of their historical ranges may be either positively (biotic acceptance) or negatively (biotic resistance) related to native biodiversity. Using data on fish community composition from two survey periods separated by approximately 28 years during which climate was warming, we examined the factors influencing the establishment of three predatory centrarchids: Smallmouth Bass (Micropterus dolomieu), Largemouth Bass (M. salmoides), and Rock Bass (Ambloplites rupestris) in lakes at their expanding northern range boundaries in Ontario. Variance partitioning demonstrated that, at a regional scale, abiotic factors play a stronger role in determining the establishment of these species than biotic factors. Pairing lakes within watersheds where each species had established with lakes sharing similar abiotic conditions where the species had not established revealed both positive and negative relationships between the establishment of centrarchids and the historical presence of other predatory species. The establishment of these species near their northern range boundaries is primarily determined by abiotic factors at a regional scale; however, biotic factors become important at the lake‐to‐lake scale. Studies of exotic species invasions have previously highlighted how spatial scale mediates the importance of abiotic vs. biotic factors on species establishment. Our study demonstrates how concepts from invasion biology can inform our understanding of the factors controlling species distributions with changing climate.
Indirect cytocompatibility of a low‐concentration hydrogen peroxide bleaching gel to odontoblast‐like cells
Authors: Soares D. G. , Marcomini N. , Basso F. G. , Pansani T. N. , Hebling J. , de Souza Costa C. A. 
Published: December 2014

AbstractAimTo assess the initial cytotoxicity and the late phenotype marker expression of odontoblast‐like cells (MDPC‐23) subjected to less aggressive in‐office bleaching therapies.MethodologyA 17.5% hydrogen peroxide (H2O2) gel was applied for 45, 15 or 5 min to enamel/dentine discs adapted to trans‐wells positioned over cultured MDPC‐23 cells. No treatment was performed on the negative control. Immediately after bleaching, the cell viability, gene expression of inflammatory mediators and quantification of H2O2 diffusion were evaluated. The ALP activity, DSPP and DMP‐1 gene expression and mineralized nodule deposition (MND) were assessed at 7, 14 or 21 days post‐bleaching and analysed statistically with Mann–Whitney U‐tests (α = 5%).ResultsH2O2 diffusion, proportional to treatment time, was observed in all bleached groups. Reductions of approximately 31%, 21% and 13% in cell viability were observed for the 45‐, 15‐ and 5‐min groups, respectively. This reduction was significant (P < 0.05) for the 45‐ and 15‐min groups, which also presented significant (P < 0.05) over‐expression of inflammatory mediators. The 45‐min group was associated with significant (P < 0.05) reductions in DMP‐1/DSPP expression at all periods, relative to control. The ALP activity and MND were reduced only in initial periods. The 15‐min group had less intense reduction of all markers, with no difference to control at 21 days.ConclusionsThe 17.5% H2O2 applied to tooth specimens for 5 min caused no alteration in the odontoblast‐like cells. When this gel was applied for 45 or 15 min, a slight cytotoxicity, associated with alterations in phenotypic markers, was observed. However, cells were able to recover their functions up to 21 days post‐bleaching.
Statistical Analysis Plan for the ‘Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke’ (TARDIS) Trial
Authors: Bath Philip M. W. , Robson Katie , Woodhouse Lisa J. , Sprigg Nikola , Dineen Robert , Pocock Stuart 
Published: December 2014

Rationale Antiplatelet agents such as aspirin, clopidogrel and dipyridamole are effective in reducing the risk of recurrence after a stroke. Importantly, the risk of recurrence is highest immediately after the index event while antiplatelets cause bleeding. Aims and/or hypothesis The ‘Triple Antiplatelets for Reducing Dependency after Ischaemic Stroke’ (TARDIS) trial is testing whether short-term intensive antiplatelet therapy is safe and effective in reducing the early risk of recurrence as compared with standard guideline-based therapy. Design TARDIS is an international multicenter prospective randomized open-label blinded-end-point trial, with funding from the UK Health Technology Assessment program. Patients with acute ischemic stroke or transient ischemic attack are randomized within 48 h to intensive/triple antiplatelet therapy or guideline antiplatelets taken for one-month. Patients or relatives give written informed (proxy) consent and all sites have research ethics approval. Analyses will be done by intention-to-treat. Study Outcome The primary outcome is shift in stroke recurrent events and their severity, assessed using the modified Rankin Scale, at three-months. Discussion This paper and attachment describe the trial's statistical analysis plan, as developed from the protocol during recruitment and prior to unblinding of data. The statistical analysis plan contains design and methods for analyses, and unpopulated tables and figures for the primary and baseline publications. The data from the trial will provide the first large-scale randomized evidence for the use of intensive anti-platelet therapy for preventing recurrence after acute stroke and transient ischemic attack.
Capital Deployment Roundtable: A Discussion of Corporate Investment and Payout Policy
Authors: Clancy Paul , Mauboussin Michael , Briscoe John , Ostfeld Scott , Hilal Paul , Milano Greg , McCormack John , Chew Don 
Published: December 2014

U.S. companies are now reportedly earning record‐high operating returns on capital while at the same time continuing to set new records both for corporate cash holdings and distributions to investors in the form of dividends and stock repurchases. But are most of these companies really maximizing value? And what role, if any, do these large distributions play in creating value? These are the two main questions that are addressed by a small group that includes two senior corporate executives and two representatives of well‐known activist investors.A number of panelists suggest that many companies, in misguided efforts to maximize returns on capital, have been using hurdle rates that are too high and so sacrificing value‐adding investment opportunities. As evidence for this claim, they cite evidence that, in recent years, the companies that have achieved the highest stock market returns appear to have made conscious decisions to reduce their returns on capital to pursue higher growth.Another increasingly common charge against U.S. companies is their tendency to pay out excessive capital to investors, especially in the form of stock repurchases at prices that turn out to be too high. But this last practice, however widespread, may not be as troubling as it has been made out to be. Although it involves a wealth transfer from existing to selling shareholders, overall investor value is lost only if such buybacks lead to corporate underinvestment. But, as a number of panelists (including the activist investors) point out, such payouts of capital have generally functioned as a demonstration of corporate managers' commitment to investing and operating with the optimal, or value‐maximizing, level of capital—neither too much nor too little.
Bridging the Gap between Interest Rates and Investments
Authors: Zenner Marc , Junek Evan , Chivukula Ram 
Published: December 2014

The links between interest rates, cost of capital, hurdle rates, and capital allocation have been remarkably weak during the last few years. For instance, whereas the current yield on the World Government Bond Index is a paltry 1.2%, survey evidence suggests that the median reported investment hurdle rate of S&P 100 companies is as high as 18%.In this report, members of J.P Morgan's corporate finance advisory group explain why the cost of capital for most companies is unlikely to increase materially even if interest rates rise as projected. This suggests that companies have room to lower their hurdle rates. Moreover, as the authors argue, a reduction in hurdle rates is likely to be beneficial since excessively high hurdle rates can have the effect of reducing value by sacrificing profitable growth opportunities and increasing the firm's risk profile. The report concludes with a framework for corporate hurdle rates and capital allocation strategies designed to help companies make better investment decisions.
Selection on outlier loci and their association with adaptive phenotypes inLittorina saxatiliscontact zones
Authors: Hollander J. , Galindo J. , Butlin R. K. 
Published: December 2014

AbstractA fundamental issue in speciation research is to evaluate phenotypic variation and the genomics driving the evolution of reproductive isolation between sister taxa. Above all, hybrid zones are excellent study systems for researchers to examine the association of genetic differentiation, phenotypic variation and the strength of selection. We investigated two contact zones in the marine gastropodLittorina saxatilisand utilized landmark‐based geometric morphometric analysis together with amplified fragment length polymorphism (AFLP) markers to assess phenotypic and genomic divergence between ecotypes under divergent selection. From genetic markers, we calculated the cline width, linkage disequilibrium and the average effective selection on a locus. Additionally, we conducted an association analysis linking the outlier loci and phenotypic variation between ecotypes and show that a proportion of outlier loci are associated with key adaptive phenotypic traits.
Lotus hosts delimit the mutualism–parasitism continuum of Bradyrhizobium
Authors: Regus J. U. , Gano K. A. , Hollowell A. C. , Sofish V. , Sachs J. L. 
Published: December 2014

AbstractSymbioses are modelled as evolutionarily and ecologically variable with fitness outcomes for hosts shifting on a continuum from mutualism to parasitism. In a classic example, rhizobia fix atmospheric nitrogen for legume hosts in exchange for photosynthetic carbon. Rhizobial infection often enhances legume growth, but hosts also incur interaction costs because of root tissues and or metabolites needed to support symbionts in planta. Rhizobia exhibit genetic variation in symbiotic effectiveness, and ecological changes in light or mineral nitrogen availability can also alter the benefits of rhizobial infection for hosts. The net effects of symbiosis thus can range from mutualistic to parasitic in a context‐dependent manner. We tested the extent of the mutualism–parasitism continuum in the legume–rhizobium symbiosis and the degree to which host investment can shape its limits. We infected Lotus strigosus with sympatric Bradyrhizobium genotypes that vary in symbiotic effectiveness. Inoculations occurred under different mineral nitrogen and light regimes spanning ecologically relevant ranges. Net growth benefits of Bradyrhizobium infection varied for Lotus and were reduced or eliminated dependent on Bradyrhizobium genotype, mineral nitrogen and light availability. But we did not detect parasitism. Lotus proportionally reduced investment in Bradyrhizobium as net benefit from infection decreased. Lotus control occurred primarily after infection, via fine‐scale modulation of nodule growth, as opposed to control over initial nodulation. Our results show how divestment of symbiosis by Lotus can prevent shifts to parasitism.