bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Ventricular Tachycardia Scar Substrate by Intracardiac Echocardiography
Authors: HUSSEIN AYMAN , JIMENEZ ALEJANDRO , AHMAD GHADA , MESUBI OLUROTIMI , KLEIN THOMAS , GURM GAGANDEEP , BECK HIROKO , SHAMS OMAR , SEE VINCENT , SALIARIS ANASTASIOS , SHOROFSKY STEPHEN , DICKFELD TIMM 
Published: October 2013

BackgroundIntracardiac echocardiography (ICE) is increasingly used to guide complex ablation procedures. This study aimed to assess the scar substrate of ventricular tachycardia (VT) by ICE in patients undergoing VT ablation.MethodsIn 22 patients undergoing VT ablation (10 ischemic, 12 nonischemic), the Biosense CARTOSOUND module (Biosense Webster, Diamond Bar, CA, USA) was used for three‐dimensional reconstruction of the ventricles. The characteristics and appearance with ICE imaging of voltage‐defined scar zones (bipolar voltage <0.5 mV), border zones (0.5–1.5 mV), and normal myocardium (>1.5 mV) on electroanatomic maps were evaluated. The standard image analysis software Image J (National Institutes of Health, Bethesda, MD, USA) was used to analyze signal intensity (mean pixel signal intensity unit [SIU]) and heterogeneity (standard deviation of signal intensity in analyzed area) on ICE images.ResultsA total of 83 myocardial areas were analyzed from two‐dimensional ICE images (15 scars, 31 border zones, and 37 normal). Voltage‐defined scar zones had increased signal intensities compared to border zones (149 SIU vs 104 SIU, P < 0.0001) and normal myocardium (88 SIU, P < 0.0001). Border zones were more likely to have heterogeneous densities compared to normal myocardium (standard deviation of signal intensity 20 SIU vs 12 SIU, P < 0.0001). In receiver‐operator characteristic analyses, signal intensity ≥137 SIU differentiated scar from nonscar zones (area under curve 0.91, P < 0.0001). Software‐based color enhancement of areas with signal intensity ≥137 SIU allowed identification of the VT substrate in all 15 patients with voltage‐defined scar zones.ConclusionsICE provides important information about the VT anatomical substrate and may have potential to identify areas of scarred myocardium.
The Role of Prophylaxis Topical Antibiotics in Cardiac Device Implantation
Authors: KHALIGHI KOROUSH , AUNG THEIN TUN , ELMI FARHAD 
Published: October 2013

BackgroundCombined systemic and topical antibiotic prophylaxes are used in cardiac electronic implantable device (CEID) procedures, but very few studies have assessed prophylactic use of topical antibiotics after CEID implantation.ObjectiveTo evaluate the efficacy of topical antibiotic prophylaxis in the prevention of surgical site infection after CEID implantation procedures.MethodsThis was a prospective randomized, placebo‐controlled, single‐center, single‐operator study. All patients (n = 1,008) received standard systemic antibiotic prophylaxis. Patients were randomized into four groups and received various topical prophylaxes after procedure. All patients were followed for at least 12 months. Surgical site inflammation and infection were graded based on degree of inflammation, discharge, wound culture, and blood culture.ResultFifty‐eight patients developed surgical site inflammation and infection. Fourteen patients had culture‐positive wound infections. Among them, 13 patients had superficial wound infections with Staphylococcus species. Only one had pocket infection with Pseudomonas bacteremia. The surgical site infection rate was higher in those with longer procedural time, associated with 2.3 times more likelihood of infection (P = 0.01). Patients with an associated malignancy were associated with 3.6 times more likelihood of infection (P < 0.01).ConclusionsCareful skin preparation prior to incision is important, whereas the use of topical antibiotics after closure has not shown significant benefit. Patients with malignancy and longer procedural times are more likely to develop infection. There is a trend for less infection with cephalic approach. Systemic antibiotics with staphylococcal coverage are needed as most of the wound culture positive infections are caused by Staphylococcus species.
The Fate of Nontargeted Endocardial Leads during the Extraction of One or More Targeted Leads in Pediatrics and Congenital Heart Disease
Authors: McCANTA ANTHONY C. , TANEL RONN E. , GRALLA JANE , RUNCIMAN DAVID MARTIN , COLLINS KATHRYN K. 
Published: October 2013

IntroductionExtraction of targeted endocardial leads can lead to inadvertent damage or dislodgement of nontargeted leads, though the frequency of this has not been reported in pediatrics and congenital heart disease (CHD).MethodsThis is a retrospective review of lead extraction procedures from 2002 to 2010 from two pediatric and CHD centers evaluating unplanned interventions on nontargeted leads during the extraction of one or more targeted leads.ResultsNontargeted leads were present in the 22 lead extraction procedures performed on 20 patients with median age 15 years (interquartile range, 11.5–18.5 years): 11 (55%) with structurally normal hearts and nine (45%) with CHD. Twenty of 23 targeted leads (86%) were extracted with complete success. Of the 22 nontargeted leads, including 17 atrial leads and five ventricular leads, seven (32%) required further intervention including: five extracted due to damage, dislodgement, or change in device location; one abandoned due to damage; and one dislodged requiring a second procedure for repositioning. The remaining 15 nontargeted leads (68%) were unharmed. Nontargeted leads requiring further intervention had a shorter lead duration in situ (median 2 years, interquartile range 0.5–3.5 years) than unharmed nontargeted leads (median 6.6 years, interquartile range 4.1–9.1 years; P = 0.01). Age at extraction, CHD, implantable cardioverter defibrillator leads, atrial lead position, or primary extraction modality did not predict further intervention for nontargeted leads. Major complications occurred in one procedure (4.5%) with no deaths.ConclusionsIn pediatrics and CHD, nontargeted leads are frequently damaged or dislodged during the extraction of targeted leads. The risk of lead damage or dislodgement has implications for procedural planning and counseling for patients and families of pediatric and CHD patients requiring lead extraction.
Oldest known avian footprints from Australia: Eumeralla Formation (Albian), Dinosaur Cove, Victoria
Authors: Martin Anthony J. , Vickers‐Rich Patricia , Rich Thomas H. , Hall Michael 
Published: October 2013

AbstractTwo thin‐toed tridactyl tracks in a fluvial sandstone bed of the Eumeralla Formation (Albian) at Dinosaur Cove (Victoria, Australia) were likely made by avian trackmakers, making these the oldest known fossil bird tracks in Australia and the only Early Cretaceous ones from Gondwana. These tracks, which co‐occur on the same surface with a slightly larger nonavian theropod track, are distinguishable by their anisodactyl form, hallux impressions and wide digit II–IV divarication angles. A lengthy hallux impression and other deformational structures associated with one track indicate foot movement consistent with an abrupt stop, suggesting its tracemaker landed after either flight or a hop. The single nonavian theropod track is similar to other tracks described from the Eumeralla Formation at another locality. The avian footprints are larger than most Early Cretaceous avian tracks recorded worldwide, indicating sizeable enantiornithine or ornithurine species in formerly polar environments of Australia. The avian tracks further supplement scant body fossil evidence of Early Cretaceous birds in southern Australia, which includes a furcula from the Wonthaggi Formation. Because of this discovery, Dinosaur Cove, previously known for its vertebrate body fossils, is added to a growing list of Early Cretaceous vertebrate tracksites in southern Australia.
A wide range of cultivated legume species act as alternative hosts for the pea aschochyta blight fungus, Didymella pinodes
Authors: Le May C. , Guibert M. , Baranger A. , Tivoli B. 
Published: October 2013

Ascochyta blight, caused by the polyphagous fungus Didymella pinodes, is one of the most economically damaging diseases of pea. Susceptibility/resistance of several legume species to several D. pinodes isolates from pea was assessed under controlled environmental conditions to test the hypothesis that D. pinodes was host‐specific. Forty‐three cultivars of five legume species (pea, common vetch, clover, alfalfa and faba bean) typically grown in temperate climates were screened with four pea‐infecting isolates from France, and one pea‐infecting isolate from Australia. Seven days after inoculation, disease incidence and necrosis were measured on foliar organs to estimate aggressiveness of the isolates. Cultivars of each legume species displayed differential resistance/susceptibility to each isolate as indicated by significant cultivar × isolate interactions in anova. Faba bean, common vetch, alfalfa and clover cultivars were consistently less susceptible than pea cultivars regardless of the inoculated isolate. The behaviour of D. pinodes isolates also indicated various patterns of disease development according to the legume species and the cultivars. Genetic distance between the five legume species was not correlated with overall differences in susceptibility, indicating that D. pinodes is not specialized to pea and shows a wide host range among legume species. Disease risk assessment in the pea crop should therefore consider the vicinity of cultivated and wild legume species that may serve as alternative hosts for D. pinodes.
Uncertainty Quantification in the Ensemble Kalman Filter
Authors: Sætrom Jon , Omre Henning 
Published: October 2013

ABSTRACTThe ensemble Kalman filter (EnKF) provides an approximate, sequential Monte Carlo solution to the recursive data assimilation algorithm for hidden Markov chains. The challenging conditioning step is approximated by a linear updating, and the updating weights, termed Kalman weights, are inferred from the ensemble members. The EnKF scheme is known to provide unstable predictions and to underestimate the prediction intervals, and even sometimes to diverge. The underlying cause for these shortcomings is poorly understood. We find that the ensemble members couple in the conditioning procedure and that the coupling increase multiplicatively in the recursive conditioning steps. Under reasonable Gauss‐independence assumptions, exact expressions for this correlation are developed. Moreover, expressions for the precision of the predictions and the downward bias in the empirical variance introduced in one conditioning step are found. These results are confirmed by a Gauss‐linear simulation study. Furthermore, we quantitatively evaluate an alternative, improved EnKF scheme on the basis of transformations of ensemble members under the same Gauss‐independent assumptions. The scheme is compared with the frequently used ensemble inflation scheme.
Social Movements and Tactical Choice
Authors: Larson Jeff A. 
Published: October 2013

AbstractFor much of the past 40 years, the study of social movement tactics has viewed organizers' choices as driven by a desire to maximize efficacy and efficiency within a context of scarce resources and structural constraints. As sociologists increasingly turned toward culture, a new orientation emerged to view tactical choice as a process of gathering, interpreting, and evaluating information within dynamic, uncertain, and often‐contradictory contexts. The importance of the cultural turn has been amply demonstrated in studies of such things as identities, emotions, and collective action frames, but the full implications of its insights continue to be discovered. Four insights in particular warrant greater attention: many core concepts in the study of social movements have an interpretive, subjective, and contingent nature; tactics are a means of communication; social structures are imbued with culture, and culture is thoroughly structured; and social movements sometimes behave irrationally, and what appears to be irrational behavior often is in fact rational. I briefly discuss three areas of scholarship – collective identities, diffusion, and institutional fields – that demonstrate innovative ways that sociologists continue to combine and incorporate these insights and point the way toward a more sophisticated understanding of social movements and tactical choice.
Community Media Studies: An Overview
Authors: Howley Kevin 
Published: October 2013

AbstractThis essay provides an overview of the field of community media studies. Like the study of “alternative media,” “citizens' media,” “independent,” and “radical” media – to mention but a few of the terms applied to participatory communication projects – academic inquiry into the structures, forms, and practices of community media has surged in recent years. While scholars often use these labels interchangeably, this essay focuses on academic and practitioner perspectives that explicitly and purposefully employ the term “community media.” The overview identifies and briefly considers three prominent conceptual frameworks – media democratization, civil society, and the symbolic construction of community – which shape and inform this vibrant field of study. This overview concludes with some thoughts on the limits and possibilities of community media theory, and practice, in the new millennium.
Intolerance Toward Immigrants in Switzerland: Diminished Threat Through Social Contacts?
Authors: Freitag Markus , Rapp Carolin 
Published: October 2013

AbstractIntolerance toward immigrants has recently reached noticeable highs in Switzerland. Referring to the conflict theory, the perception of a specific group as a threat tends to lead to intolerance toward that group. The expectation of a negative relationship between threat and tolerance is nevertheless not assumed to be universally valid for all members of society. In particular, the contact theory assumes that intercultural encounters should promote positive attitudes toward culturally different individuals and groups. Using a new and unique data set, our Heckman selection models reveal that Swiss who view rising immigration to mean a loss of economic privileges and an erosion of Swiss cultural values are less tolerant toward immigrants. Moreover, our results indicate that contact with immigrants may moderate this effect. However, not all group settings are able to reduce the perceived threats in a similar way, and not all sorts of social contact are able to foster tolerance toward immigrants.
Evaluation of two chlorhexidine – alcohol‐based skin disinfectants in blood donation setting
Authors: So B. K. L. , Chu C. C. Y. , Ho P. L. , Chow K. H. , Leung J. N. S. , Lee I. Y. M. , Lin C. K. , Lee C. K. 
Published: October 2013

BackgroundSource reduction is important in minimizing bacterial‐contaminated risk of blood products, but previous evaluation of chlorhexidine (CHX) was confounded by inability of Tween and lecithin to neutralize CHX. The study aims to address this limitation and also evaluates the effectiveness of two CHX–alcohol‐based skin disinfectants in blood donation setting.MethodsA two‐stage observational study was conducted. A single step 2% chlorhexidine gluconate/70% isopropyl alcohol brush (CHX/IPA‐1) was first compared with current skin disinfection procedure consisting of sequential application of 10% povidone‐iodine and 70% isopropyl alcohol (PI/IPA). Standard plates with conventional neutralizers (0·3% Tween‐80, 0·1% lecithin) were used to enumerate residual bacterial counts. Then, CHX/IPA‐1 was compared with another applicator CHX/IPA‐2 with identical disinfectant contents using in‐house plates with neutralizers (3% Tween‐80, 0·3% lecithin, 0·1% histidine, 0·5% sodium thiosulphate, 3% saponin, 1% ether sulphate) having enhanced ability to neutralize CHX.ResultsAll three products were found to reduce plate counts by > 2 log10 after disinfection. The CHX/IPA‐1 group gave fewer residual bacterial growth on standard plates than PI/IPA group (5·9% vs. 61·7%, P < 0·001). With the use of in‐house plates, residual bacterial growth was of no difference in both CHX/IPA‐1 and CHX/IPA‐2 groups (42·5% vs. 49·4%, P = 0·26).ConclusionGood efficacy was observed with one‐stage application of CHX/IPA in predonation skin disinfection and it could replace PI/IPA. However, the efficacy of CHX/IPA could be grossly overestimated in testing with standard plates because of insufficient neutralization.
Physiological roles of glucocorticoids during early embryonic development of the zebrafish (Danio rerio)
Authors: Wilson K. S. , Matrone G. , Livingstone D. E. W. , Al‐Dujaili E. A. S. , Mullins J. J. , Tucker C. S. , Hadoke P. W. F. , Kenyon C. J. , Denvir M. A. 
Published: October 2013

Key pointsGlucocorticoids are known to be present in the developing zebrafish embryo but little is known about their physiological role at this early stage.The zebrafish embryo demonstrates a functional glucocorticoid system from around 48 h post fertilisation.This system and the stress response is amenable to pharmacological and genetic manipulation in a manner predicted by mammalian physiology.Glucocorticoids play a key developmental role in hatching, swimming and stress response.The zebrafish embryo is a relevant model for the study of glucocorticoid physiology.Abstract While glucocorticoids (GCs) are known to be present in the zebrafish embryo, little is known about their physiological roles at this stage. We hypothesised that GCs play key roles in stress response, hatching and swim activity during early development. To test this, whole embryo cortisol (WEC) and corticosteroid‐related genes were measured in embryos from 6 to 120 h post fertilisation (hpf) by enzyme linked immunosorbent assay (ELISA) and quantitative real‐time polymerase chain reaction (qRT‐PCR). Stress response was assessed by change in WEC following stirring, hypoxia or brief electrical impulses applied to the bathing water. The impact of pharmacological and molecular GC manipulation on the stress response, spontaneous hatching and swim activity at different stages of development was also assessed. WEC levels demonstrated a biphasic pattern during development with a decrease from 0 to 36 hpf followed by a progressive increase towards 120 hpf. This was accompanied by a significant and sustained increase in the expression of genes encodingcyp11b1(GC biosynthesis),hsd11b2(GC metabolism) andgr(GC receptor) from 48 to 120 hpf. Metyrapone (Met), an inhibitor of 11β‐hydroxylase (encoded bycyp11b1), andcyp11b1morpholino (Mo) knockdown significantly reduced basal and stress‐induced WEC levels at 72 and 120 hpf but not at 24 hpf. Spontaneous hatching and swim activity were significantly affected by manipulation of GC action from approximately 48 hpf onwards. We have identified a number of key roles of GCs in zebrafish embryos contributing to adaptive physiological responses under adverse conditions. The ability to alter GC action in the zebrafish embryo also highlights its potential value for GC research.
Novel magnetomechanical MR compatible vibrational device for producing kinesthetic illusion during fMRI
Authors: Carr Sarah J. , Borreggine Kristin , Heilman Jeremiah , Griswold Mark , Walter Benjamin L. 
Published: October 2013

Purpose:Functional MRI (fMRI) can provide insights into the functioning of the sensorimotor system, which is of particular interest in studying people with movement disorders or chronic pain conditions. This creates a demand for manipulanda that can fit and operate within the environment of a MRI scanner. Here, the authors present a magnetomechanical device that delivers a vibrotactile sensation to the skin with a force of approximately 9 N.Methods:MRI compatibility of the device was tested in a 3 T scanner using a phantom to simulate the head. Preliminary investigation into the effectiveness of the device at producing cortical and subcortical activity was also conducted with a group of seven healthy subjects. The vibration was applied to the right extensor carpi ulnaris tendon to induce a kinesthetic illusion of flexion and extension of the wrist.Results:The MRI compatibility tests showed the device did not produce image artifacts and the generated electromagnetic field did not disrupt the static magnetic field of the scanner or its operation. The subject group results showed activity in the contralateral putamen, premotor cortex, and dorsal lateral prefrontal cortex. Ipsilaterally, there was increased activity in the superior and inferior parietal lobules. Areas that activated bilaterally included the thalamus, anterior cingulate, secondary somatosensory areas (S2), temporal lobes, and visual association areas.Conclusions:This device offers an effective tool with precise control over the vibratory stimulus, delivering higher forces than some other types of devices (e.g., piezoelectric actuators). It can be useful for investigating sensory systems and sensorimotor integration.
Algorithmic scatter correction in dual‐energy digital mammography
Authors: Chen Xi , Nishikawa Robert M. , Chan Suk‐tak , Lau Beverly A. , Zhang Lei , Mou Xuanqin 
Published: October 2013

Purpose:Small calcifications are often the earliest and the main indicator of breast cancer. Dual‐energy digital mammography (DEDM) has been considered as a promising technique to improve the detectability of calcifications since it can be used to suppress the contrast between adipose and glandular tissues of the breast. X‐ray scatter leads to erroneous calculations of the DEDM image. Although the pinhole‐array interpolation method can estimate scattered radiations, it requires extra exposures to measure the scatter and apply the correction. The purpose of this work is to design an algorithmic method for scatter correction in DEDM without extra exposures.Methods:In this paper, a scatter correction method for DEDM was developed based on the knowledge that scattered radiation has small spatial variation and that the majority of pixels in a mammogram are noncalcification pixels. The scatter fraction was estimated in the DEDM calculation and the measured scatter fraction was used to remove scatter from the image. The scatter correction method was implemented on a commercial full‐field digital mammography system with breast tissue equivalent phantom and calcification phantom. The authors also implemented the pinhole‐array interpolation scatter correction method on the system. Phantom results for both methods are presented and discussed. The authors compared the background DE calcification signals and the contrast‐to‐noise ratio (CNR) of calcifications in the three DE calcification images: image without scatter correction, image with scatter correction using pinhole‐array interpolation method, and image with scatter correction using the authorsˈ algorithmic method.Results:The authorsˈ results show that the resultant background DE calcification signal can be reduced. The root‐mean‐square of background DE calcification signal of 1962μm with scatter‐uncorrected data was reduced to 194 μm after scatter correction using the authorsˈ algorithmic method. The range of background DE calcification signals using scatter‐uncorrected data was reduced by 58% with scatter‐corrected data by algorithmic method. With the scatter‐correction algorithm and denoising, the minimum visible calcification size can be reduced from 380 to 280 μm.Conclusions:When applying the proposed algorithmic scatter correction to images, the resultant background DE calcification signals can be reduced and the CNR of calcifications can be improved. This method has similar or even better performance than pinhole‐array interpolation method in scatter correction for DEDM; moreover, this method is convenient and requires no extra exposure to the patient. Although the proposed scatter correction method is effective, it is validated by a 5‐cm‐thick phantom with calcifications and homogeneous background. The method should be tested on structured backgrounds to more accurately gauge effectiveness.