bluuebunny/crossref_metadata_2025_split huggingface dataset:
A permissive chromatin structure is adopted prior to site-specific DNA demethylation of developmentally expressed genes involved in macronuclear differentiation
Authors: Bulic Aneta , Postberg Jan , Fischer Andreas , Jönsson Franziska , Reuter Günter , Lipps Hans J 
Published: March 2013

Abstract

Background
DNA methylation and demethylation are important epigenetic regulatory mechanisms in eukaryotic cells and, so far, only partially understood. We exploit the minimalistic biological ciliate system to understand the crosstalk between DNA modification and chromatin structure. In the macronucleus of these cells, the DNA is fragmented into individual short DNA molecules, each representing a functional expression and replication unit. Therefore, long range epigenomic interaction can be excluded in this system.

Results
In the stichotrichous ciliate Stylonychia lemnae, cytosine methylation occurs in a small subset of macronuclear nanochromosomes expressed only during sexual reproduction. Methylation pattern shows similarity to that observed in fungi and Drosophila. Cytosine methylation correlates with gene activity and chromatin structure. Upon gene activation, cytosines become demethylated and a redistribution of histone post-translational modifications (PTMs) takes place. Evidence is presented that the formation of a permissive chromatin structure in the vicinity of the 5meCs precedes cytosine methylation and is probably a necessary prerequisite for their demethylation. Shortly after demethylation of cytosines occurs, the parental macronucleus degenerates, a new macronucleus is formed from a micronuclear derivative and the specific methylation pattern is transmitted from the germline micronucleus to the new macronucleus.

Conclusions
We show that very few, or even only one, discrete methylated cytosines are required to assign regulatory functions at a specific locus. Furthermore, evidence is provided that a permissive chromatin structure is probably a necessary prerequisite for the demethylation of specific cytosines. Our results allow us to propose a mechanistic model for the biological function of cytosine methylation in the ciliate cell and its regulation during the cell cycle.
Reliability of ultrasound imaging in the assessment of the dorsal Lisfranc ligament
Authors: Rettedal David D , Graves Nathan C , Marshall Joshua J , Frush Katherine , Vardaxis Vassilios 
Published: March 2013

AbstractBackgroundThe Lisfranc ligament plays an integral role in providing stability to the midfoot. Variable clinical presentations and radiographic findings make injuries to the Lisfranc ligament notoriously difficult to diagnose. Currently, radiographic evaluation is the mainstay in imaging such injuries; however, ultrasound has been suggested as a viable alternative. The objective of this study was to evaluate the intra‐rater and inter‐rater reliability in the measurement of the length of the dorsal Lisfranc ligament using ultrasound imaging in healthy, asymptomatic subjects.MethodsThe dorsal Lisfranc ligaments of fifty asymptomatic subjects (n = 100 feet) were imaged using a Siemens SONOLINE Antares Ultrasound Imaging System© under low, medium, and high stress loads at 0° and 15° abducted foot positions. The lengths of the ligaments were measured, and Interclass correlation coefficients were used to calculate within‐session intra‐rater reliability (n = 100 feet) as well as between‐session intra‐rater reliability (n = 40 feet) and between‐session inter‐rater reliability (n = 40 feet).ResultsThe within‐session intra‐rater reliability results for dorsal Lisfranc ligament length had an average ICC of 0.889 (min 0.873 max 0.913). The average ICC for between‐session intra‐rater reliability was 0.747 (min 0.607 max 0.811). The average ICC for between‐session inter‐rater reliability was 0.685 (min 0.638 max 0.776).ConclusionsThe measurement of the dorsal Lisfranc ligament length using ultrasound imaging shows substantial to almost perfect reliability when evaluating asymptomatic subjects. This imaging modality methodology shows promise and lays the foundation for further work in technique development towards the diagnostic identification of pathology within the Lisfranc ligament complex.
Physiological predictors of survival during high-frequency oscillatory ventilation inadults with acute respiratory distress syndrome
Authors: Camporota Luigi , Sherry Tony , Smith John , Lei Katie , McLuckie Angela , Beale Richard 
Published: March 2013

Abstract
Introduction
Data that provide clinical criteria for the identification of patients likely torespond to high-frequency oscillatory ventilation (HFOV) are scarce. Our aim wasto describe physiological predictors of survival during HFOV in adults with severeacute respiratory distress syndrome (ARDS) admitted to a respiratory failurecenter in the United Kingdom.

Methods
Electronic records of 102 adults treated with HFOV were reviewed retrospectively.We used logistic regression and receiving-operator characteristics curve to testassociations with oxygenation and mortality.

Results
Patients had severe ARDS with a mean (SD) Murray's score of 2.98 (0.7). Partialpressure of oxygen in arterial blood to fraction of inspired oxygen(PaO2/FiO2) ratio and oxygenation index improved only insurvivors. The earliest time point at which the two groups differed was at threehours after commencing HFOV. An improvement of >38% inPaO2/FiO2 occurring at any time within the first 72hours, was the best predictor of survival at 30 days (area under the curve (AUC)of 0.83, sensitivity 93%, specificity 78% and a positive likelihood ratio (LR) of4.3). These patients also had a 3.5 fold greater reduction in partial pressure ofcarbon dioxide in arterial blood (PaCO2). Multivariate analysis showedthat HFOV was more effective in younger patients, when instituted early, and inpatients with milder respiratory acidosis.

Conclusions
HFOV is effective in improving oxygenation in adults with ARDS, particularly wheninstituted early. Changes in PaO2/FiO2 during the firstthree hours of HFOV can identify those patients more likely to survive.
Beyond the bundle - journey of a tertiary care medical intensive care unit to zerocentral line-associated bloodstream infections
Authors: Exline Matthew C , Ali Naeem A , Zikri Nancy , Mangino Julie E , Torrence Kelly , Vermillion Brenda , St Clair Jamie , Lustberg Mark E , Pancholi Preeti , Sopirala Madhuri M 
Published: March 2013

Abstract
Introduction
We set a goal to reduce the incidence rate of catheter-related bloodstreaminfections to rate of <1 per 1,000 central line days in a two-year period.

Methods
This is an observational cohort study with historical controls in a 25-bedintensive care unit at a tertiary academic hospital. All patients admitted to theunit from January 2008 to December 2011 (31,931 patient days) were included. Amultidisciplinary team consisting of hospital epidemiologist/infectious diseasesphysician, infection preventionist, unit physician and nursing leadership wasconvened. Interventions included: central line insertion checklist, demonstrationof competencies for line maintenance and access, daily line necessity checklist,and quality rounds by nursing leadership, heightened staff accountability,follow-up surveillance by epidemiology with timely unit feedback and case reviews,and identification of noncompliance with evidence-based guidelines. Molecularepidemiologic investigation of a cluster of vancomycin-resistant Enterococcusfaecium (VRE) was undertaken resulting in staff education forproper acquisition of blood cultures, environmental decontamination and dailychlorhexidine gluconate (CHG) bathing for patients.

Results
Center for Disease Control/National Health Safety Network (CDC/NHSN) definitionwas used to measure central line-associated bloodstream infection (CLA-BSI) ratesduring the following time periods: baseline (January 2008 to December 2009),intervention year (IY) 1 (January to December 2010), and IY 2 (January to December2011). Infection rates were as follows: baseline: 2.65 infections per 1,000catheter days; IY1: 1.97 per 1,000 catheter days; the incidence rate ratio (IRR)was 0.74 (95% CI = 0.37 to 1.65, P = 0.398); residual seven CLA-BSIsduring IY1 were VRE faecium blood cultures positive from central linealone in the setting of findings explicable by noninfectious conditions. Followingstaff education, environmental decontamination and CHG bathing (IY2): 0.53 per1,000 catheter days; the IRR was 0.20 (95% CI = 0.06 to 0.65, P = 0.008)with 80% reduction compared to the baseline. Over the two-year interventionperiod, the overall rate decreased by 53% to 1.24 per 1,000 catheter-days (IRR of0.47 (95% CI = 0.25 to 0.88, P = 0.019) with zero CLA-BSI for a total of15 months.

Conclusions
Residual CLA-BSIs, despite strict adherence to central line bundle, may be relatedto blood culture contamination categorized as CLA-BSIs per CDC/NHSN definition.Efforts to reduce residual CLA-BSIs require a strategic multidisciplinary teamapproach focused on epidemiologic investigations of practitioner- or unit-specificetiologies.
Asset-Pricing Implications of Dividend Volatility
Authors: Li Yan , Yang Liyan 
Published: March 2013

This paper establishes dividend volatility as a fundamental risk metric that prices assets. We theoretically incorporate dividend volatility clustering into a model in which narrow-framing investors are loss averse over fluctuations in the value of their investments. Our model shows that dividend volatility positively predicts future asset returns, with the predictive power increasing with the forecasting horizon; our model also sheds light on a variety of other asset-pricing phenomena. We further provide supporting empirical evidence that dividend volatility is indeed priced in the data. More specifically, aggregate dividend volatility predicts and is predicted by aggregate price-to-dividend ratios; aggregate dividend volatility predicts future aggregate market returns; and dividend volatility of portfolios sorted by size, book-to-market ratios, and past returns predicts future portfolio-level returns, respectively. This paper was accepted by Wei Xiong, finance.
Thoracic surgical management of colorectal lung metastases: a questionnaire survey of members of the Society for Cardiothoracic Surgery in great Britain and Ireland
Authors: Jegatheeswaran S , Satyadas T , Sheen AJ , Treasure T , Siriwardena AK 
Published: March 2013

Introduction Distant metastases to liver and lung are not uncommon in colorectal cancer. Resection of metastases is accepted widely as the standard of care. However, there is no firm evidence base for this. This questionnaire survey was carried out to assess the current practice preferences of cardiothoracic surgeons in Great Britain and Ireland. Methods An online questionnaire survey was emailed to cardiothoracic surgeons in Great Britain and Ireland. The survey was live for 12 weeks. Responses were collated with SurveyMonkey®. Results Overall, there were 75 respondents. The majority (83%) indicated thoracic surgery as a specialist interest. Almost all (99%) used thoracic computed tomography (CT) for staging; 70% added liver CT and 51% added pelvic CT. Fluorodeoxyglucose positron emission tomography was used by 86%. The most frequent indication for pulmonary resection (97%) was solitary lung metastasis without extrathoracic disease. Video assisted thoracoscopic surgery (VATS) was used by 85%. In addition, thoracotomy was used by 96%. A third (33%) used radiofrequency ablation. Synchronous liver and lung resection was contraindicated for 83% of respondents. Over three-quarters (77%) thought that scientific equipoise exists presently for lung resection for colorectal lung metastases but only 21% supported a moratorium on this type of surgery until further evidence becomes available. Conclusions The results confirm that the majority of respondents use conventional cross-sectional imaging and either VATS or formal thoracotomy for resection. The results emphasise the continuing need for formal randomised trials to provide evidence of any survival benefit from pulmonary metastasectomy for colorectal lung metastases.
CONFERENCE REPORT
Authors: Tomaselli Keyan G. 
Published: March 2013

BEYOND ENCODING/DECODING: ZOMBIES, WITCHCRAFT AND STAMMERING NORMATIVE THEORY
BEYOND NORMATIVE APPROACHES: EVERYDAY MEDIA CULTURE IN AFRICA, UNIVERSITY OF THE WITWATERSRAND, THE UNIVERSITY OF MICHIGAN AND THE UNIVERSITY OF WESTMINSTER, JOHANNESBURG, SOUTH AFRICA, 27–29 FEBRUARY
2012
Plattformstrategien für altes und neues Wissen
Authors: Sternitzke Nicolai 
Published: March 2013

Zusammenfassung
Digitale Informationsdienstleistungen und elektronische Publikationsangebote sind in den letzten Jahren zum elementaren Bestandteil der wissenschaftlichen Literaturversorgung in der internationalen Bibliothekslandschaft geworden. Durch den technologischen Wandel und die daraus resultierenden Nutzeranforderungen verfolgen auch Archive und museale Einrichtungen zunehmend den Anspruch, ihre einzigartigen Sammlungsbestände und forschungsrelevantes Schrifttum im Sinne des Open Access digital zu veröffentlichen und damit einen zeit- und ortsunabhängigen Online-Zugriff auf die Materialien zu gewährleisten. Dabei spielen Nutzerorientierung, Funktionalität und Effizienz der Digitalisierungs- und Erschließungsprozesse eine ebenso tragende Rolle wie konservatorische Überlegungen zum Schutz und zur Langzeitsicherung des kulturellen Erbes. Die von der Wienbibliothek im Rathaus veranstaltete Fachkonferenz zur Digitalisierung bot zu diesem Themenspektrum facettenreiche Fachvorträge und Projektberichte aus der Anwenderperspektive verschiedener Informationseinrichtungen Österreichs, der Schweiz und Deutschlands, die im Folgenden zusammenfassend dargestellt werden.
Intragenomic Conflict Between the Two Major Knob Repeats of Maize
Authors: Kanizay Lisa B , Albert Patrice S , Birchler James A , Dawe R Kelly 
Published: March 2013

AbstractExamples of meiotic drive, the non-Mendelian segregation of a specific genomic region, have been identified in several eukaryotic species. Maize contains the abnormal chromosome 10 (Ab10) drive system that transforms typically inert heterochromatic knobs into centromere-like domains (neocentromeres) that move rapidly poleward along the spindle during meiosis. Knobs can be made of two different tandem repeat sequences (TR-1 and 180-bp repeat), and both repeats have become widespread in Zea species. Here we describe detailed studies of a large knob on chromosome 10 called K10L2. We show that the knob is composed entirely of the TR-1 repeat and is linked to a strong activator of TR-1 neocentromere activity. K10L2 shows weak meiotic drive when paired with N10 but significantly reduces the meiotic drive exhibited by Ab10 (types I or II) in Ab10/K10L2 heterozygotes. These and other data confirm that (1) there are two separate and independent neocentromere activities in maize, (2) that both the TR-1 and knob 180 repeats exhibit meiotic drive (in the presence of other drive genes), and (3) that the two repeats can operate in competition with each other. Our results support the general concept that tandem repeat arrays can engage in arms-race-like struggles and proliferate as an outcome.
Identifying Loci Under Selection Against Gene Flow in Isolation-with-Migration Models
Authors: Sousa Vitor C , Carneiro Miguel , Ferrand Nuno , Hey Jody 
Published: March 2013

AbstractWhen divergence occurs in the presence of gene flow, there can arise an interesting dynamic in which selection against gene flow, at sites associated with population-specific adaptations or genetic incompatibilities, can cause net gene flow to vary across the genome. Loci linked to sites under selection may experience reduced gene flow and may experience genetic bottlenecks by the action of nearby selective sweeps. Data from histories such as these may be poorly fitted by conventional neutral model approaches to demographic inference, which treat all loci as equally subject to forces of genetic drift and gene flow. To allow for demographic inference in the face of such histories, as well as the identification of loci affected by selection, we developed an isolation-with-migration model that explicitly provides for variation among genomic regions in migration rates and/or rates of genetic drift. The method allows for loci to fall into any of multiple groups, each characterized by a different set of parameters, thus relaxing the assumption that all loci share the same demography. By grouping loci, the method can be applied to data with multiple loci and still have tractable dimensionality and statistical power. We studied the performance of the method using simulated data, and we applied the method to study the divergence of two subspecies of European rabbits (Oryctolagus cuniculus).
Effects of Genetic Drift and Gene Flow on the Selective Maintenance of Genetic Variation
Authors: Star Bastiaan , Spencer Hamish G 
Published: March 2013

Abstract
Explanations for the genetic variation ubiquitous in natural populations are often classified by the population–genetic processes they emphasize: natural selection or mutation and genetic drift. Here we investigate models that incorporate all three processes in a spatially structured population, using what we call a construction approach, simulating finite populations under selection that are bombarded with a steady stream of novel mutations. As expected, the amount of genetic variation compared to previous models that ignored the stochastic effects of drift was reduced, especially for smaller populations and when spatial structure was most profound. By contrast, however, for higher levels of gene flow and larger population sizes, the amount of genetic variation found after many generations was greater than that in simulations without drift. This increased amount of genetic variation is due to the introduction of slightly deleterious alleles by genetic drift and this process is more efficient when migration load is higher. The incorporation of genetic drift also selects for fitness sets that exhibit allele-frequency equilibria with larger domains of attraction: they are “more stable.” Moreover, the finiteness of populations strongly influences levels of local adaptation, selection strength, and the proportion of allele-frequency vectors that can be distinguished from the neutral expectation.
Improved Switching Response of VO2 Devices Deposited on Silicon Nitride Membranes
Authors: Wang Yan , Muth John F. 
Published: March 2013

ABSTRACTVO2films were deposited on sapphire, ITO glass and 200 nm thick silicon nitride membranes by Pulsed Laser Deposition (PLD). The electrical and optical properties have been investigated. Joule heating devices fabricated on silicon nitride membranes switches from semiconductor phase to metal phase by applying a constant voltage across two metal contacts. Compared to the devices fabricated on the normal substrates, such as sapphire, silicon or glasses, the switching speed of the devices on membrane is an order of magnitude faster. Decreasing the area and thickness of VO2 on top of thinner membranes allows kHz bandwidth to be achieved.
Magnetic Interactions Study in ZnO Doped with Fe Ions Produced by Thermal Diffusion Processes
Authors: Baca R. , Galván M. , Méndez J. V. , Andraca J. A. , Peña R. 
Published: March 2013

ABSTRACTRecently, the oxides have received attention and great interest due to their magnetic ordering above of the room temperature by doping a very low amount of transition metal ions, which are very promising for applications such as biosensing, hyperthermia, doped magnetic semiconductors with lower energy losses and rapid response at alternating-magnetic fields. In this work the magnetic interactions on Fe doped ZnO thin-films was studied. Raman spectroscopy allowed the monitoring of iron ions diffusion and demonstrated that symmetry modes are crucial for understanding of the magnetic ordering. X-ray diffraction (XRD) was used to determine the oxidation state of the iron ions and stress into ZnO lattice. MFM confirmed that magnetic moments and magnetic forces on scanned surface depend on magnetic-domain structure formation.
The Use of High Durability Alumino-Borosilicate Glass for the Encapsulation of High Temperature Reactor (HTR) Fuel
Authors: Heath Paul G. , Stennett Martin C. , McGann Owen J. , Hand Russell J. , Hyatt Neil C. 
Published: March 2013

ABSTRACTThe development of suitable waste forms for waste produced by generation IV reactors is of critical concern for future operations. To date no accepted disposal route for Tri-Structural Isotropic (TRISO) High Temperature Reactor (HTR) fuel exists. Alumino-borosilicate glass has been studied for its ability to encapsulate TRISO particle fuels. This glass was selected for its high aqueous durability. Encapsulation was achieved by cold pressing and sintering of glass powders mixed with HTR fuel. Sintering profiles capable of eliminating interconnected porosity in the composites were developed. The chemical compatibility and wetting of the glass matrix with the fuel were analysed along with the aqueous durability of the sintered glass matrix. Composites sintered under a controlled atmosphere produced unfractured monoliths with minimal chemical interaction between the glass and the TRISO particles. The Product Consistency Test (PCT) durability assessment indicated the sintered alumino-borosilicate glass was approximately an order of magnitude more durable than an equivalent R7T7 borosilicate glass. These results suggest sintered alumino-borosilicate glass-TRISO particle composites may provide a potential disposal route for spent TRISO particle fuel.
Compressive Fracture Behavior of Bi-added Ni50Mn28Ga22 Ferromagnetic Shape Memory Alloys
Authors: Tanimura Hirotaka , Tahara Masaki , Inamura Tomonari , Hosoda Hideki 
Published: March 2013

ABSTRACTIn order to develop NiMnGa/polymer composite materials, a production of single-crystal-like NiMnGa particles is important and should be developed for better quality. Although mechanical pulverization is a promising method by utilizing intrinsic intergranular brittleness of NiMnGa polycrystalline ingots, the amount of lattice defects introduced during mechanical crushing needs to be minimized. This must be achieved by enhancement of intergranular brittleness of NiMnGa particles. In this study, the effect of Bi addition on the compressive fracture behavior of polycrystalline Ni50Mn28Ga22 was investigated where Bi was expected to be segregated to the grain boundaries in NiMnGa, similar to Bi segregation to the grain boundaries in Ni. It was found that only intergranular fracture was observed in Ni50Mn28Ga22 polycrystals with 0.3 at.% Bi addition, although a mixture of intergranular and transgranular fracture was observed in Bi-free Ni50Mn28Ga22 polycrystal. Microalloying of Bi into NiMnGa enhances intergranular embrittlement. A number of spherical particles of Bi were confirmed on the fractured surface of Bi-doped NiMnGa polycrystals. The formation of Bi particles is a proof of the grain boundary segregation of Bi in NiMnGa.
Expanded Thermochromic Color Changes in VO2 Thin Film Devices Using Structured Plasmonic Metal Layers
Authors: Wang Yan , Muth John F. 
Published: March 2013

ABSTRACTWe investigate metallic thin films on VO2 and show that the magnitude of the reflected color change in that visible portion of the spectrum as VO2 undergoes the insulating to metallic phase transition can be controlled by changing the type of metal, the thickness of the metal and by patterning the metal at the nano scale. We consider the role of surface plasmas in the metal film and show that in the near infrared, the magnitude of the reflectivity increase for metal coated VO2 films, but decrease for uncoated VO2 thin films. This is explained in the context of Fresnel equations and considering the large change in the imaginary part of the dielectric constant as the VO2 changes state from the insulating to metallic phase.