544 research outputs found
Surrogate model for gravitational wave signals from non-spinning, comparable- to large-mass-ratio black hole binaries built on black hole perturbation theory waveforms calibrated to numerical relativity
We present a reduced-order surrogate model of gravitational waveforms from non-spinning binary black hole systems with comparable to large mass-ratio configurations. This surrogate model, \texttt{BHPTNRSur1dq1e4}, is trained on waveform data generated by point-particle black hole perturbation theory (ppBHPT) with mass ratios varying from 2.5 to 10,000. \texttt{BHPTNRSur1dq1e4} extends an earlier waveform model, \texttt{EMRISur1dq1e4}, by using an updated transition-to-plunge model, covering longer durations up to 30,500 (where is the mass of the primary black hole), includes several more spherical harmonic modes up to , and calibrates subdominant modes to numerical relativity (NR) data. In the comparable mass-ratio regime, including mass ratios as low as , the gravitational waveforms generated through ppBHPT agree surprisingly well with those from NR after this simple calibration step. We also compare our model to recent SXS and RIT NR simulations at mass ratios ranging from to , and find the dominant quadrupolar modes agree to better than . We expect our model to be useful to study intermediate-mass-ratio binary systems in current and future gravitational-wave detectors
Integrated Management Strategies for Phytophthora sojae Combining Host Resistance and Seed Treatments
Phytophthora sojae has re-emerged as a serious soybean pathogen in the past decade. This may be due in part to changes in resistance levels in current cultivars, adoption of P. sojae populations to deployed Rps genes, and highly favorable environments in the past decade. This multilocation study evaluated the effect of seed treatments on the incidence and severity of Phytophthora root and stem rot on soybeans with different combinations of Rps genes and levels of partial resistance. The efficacy of the seed treatments was highly variable across locations. Seed treatments (metalaxyl and mefenoxam) provided protection and increased yields across cultivars in locations where rain or irrigation occurred shortly after planting (Ohio, South Dakota, and Ontario). However, there were no significant differences in stand or yield consistently across cultivars in Iowa, Nebraska, Wisconsin, or Ohio, where heavy precipitation did not occur until later growth stages. The environment, levels of inoculum, and pathogen complex may have played a role in the different responses to the seed treatments and to the different combinations of Rps genes and levels of partial resistance to P. sojae in the cultivars. Fields that are poorly drained and have P. sojae populations with complex pathotypes may benefit the most from seed treatments. Individual fields where producers may see the greatest benefit to utilizing these integrated management strategies will need to be identified
Role of hemoclips in the management of acute bleeding from a gastric stromal tumor: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Though gastrointestinal stromal tumors (GISTs) frequently present with gastrointestinal bleeding, the guidelines for the management and control of bleeding are unclear especially in patients who are not appropriate for surgical resection.</p> <p>Case presentation</p> <p>We report a case of gastric GIST in an elderly patient who presented with bleeding. Homeostasis was achieved initially with the endoscopic placement of a hemoclip followed by treatment with the tyrosine kinase inhibitor, imatinib.</p> <p>Conclusion</p> <p>The management of bleeding GISTs in the elderly pose a challenging task to the gastroenterologist and treatment strategies should be tailored to the expertise of the endoscopist, surgeon and other supportive staff.</p
Prehospital 12-Lead Electrocardiogram within 60 Minutes Differentiates Proximal versus Nonproximal Left Anterior Descending Artery Myocardial Infarction
<p>Introduction: Acute anterior myocardial infarctions caused by proximal left anterior descending (LAD) artery occlusions are associated with a higher morbidity and mortality. Early identification of high-risk patients via the 12-lead electrocardiogram (ECG) could assist physicians and emergency response teams in providing early and aggressive care for patients with anterior ST-elevation myocardial infarctions (STEMI). Approximately 25% of US hospitals have primary percutaneous coronary intervention (PCI) capability for the treatment of acute myocardial infarctions. Given the paucity of</p> <p>hospitals capable of PCI, early identification of more severe myocardial infarction may prompt</p> <p>emergency medical service routing of these patients to PCI-capable hospitals. We sought to determine if the 12 lead ECG is capable of predicting proximal LAD artery occlusions.</p> <p>Methods: In a retrospective, post-hoc analysis of the Pre-Hospital Administration of Thrombolytic Therapy with Urgent Culprit Artery Revascularization pilot trial, we compared the ECG findings of</p> <p>proximal and nonproximal LAD occlusions for patients who had undergone an ECG within 180 minutes of symptom onset.</p> <p>Results: In this study, 72 patients had anterior STEMIs, with ECGs performed within 180 minutes of symptom onset. In patients who had undergone ECGs within 60 minutes (n¼35), the mean sum of ST elevation (STE) in leads V1 through V6 plus ST depression (STD) in leads II, III, and aVF was 19.2 mm for proximal LAD occlusions and 11.7 mm for nonproximal LAD occlusions (P¼0.007). A sum STE in V1 through V6 plus STD in II, III, and aVF of at least 17.5 mm had a sensitivity of 52.3%, specificity of 92.9%, positive predictive value of 91.7%, and negative predictive value of 56.5% for proximal LAD occlusions. When the ECG was performed more than 60 minutes after symptom onset (n¼37), there was no significant difference in ST-segment deviation between the 2 groups.</p> <p>Conclusion: The sum STE (V1-V6) and STD (II, III, aVF) on a 12-lead ECG can be used to predict proximal LAD occlusions if performed within the first hour of symptom onset. This should be considered a high-risk finding and may prompt prehospital direction of such patients to PCI-capable hospitals. [West J Emerg Med. 2011;12(4):408–413.]</p
De flora en vegetatie van lijnvormige beplantingen in Nederland
Climate change effects on freshwater biogeochemistry and riverine loads of biogenic elements to the Baltic Sea are not straight forward and are difficult to distinguish from other human drivers such as atmospheric deposition, forest and wetland management , eutrophication and hydrological alterations. Eutrophication is by far the most well-known factor affecting the biogeochemistry of the receiving waters in the various sub-basins of the Baltic Sea. However, the present literature review reveals that climate change is a compounding factor for all major drivers of freshwater biogeochemistry discussed here, although evidence is still often based on short-term and/or small-scale studies
Simulating magnetized neutron stars with discontinuous Galerkin methods
Discontinuous Galerkin methods are popular because they can achieve high order where the solution is smooth, because they can capture shocks while needing only nearest-neighbor communication, and because they are relatively easy to formulate on complex meshes. We perform a detailed comparison of various limiting strategies presented in the literature applied to the equations of general relativistic magnetohydrodynamics. We compare the standard minmod/ limiter, the hierarchical limiter of Krivodonova, the simple WENO limiter, the HWENO limiter, and a discontinuous Galerkin-finite-difference hybrid method. The ultimate goal is to understand what limiting strategies are able to robustly simulate magnetized TOV stars without any fine-tuning of parameters. Among the limiters explored here, the only limiting strategy we can endorse is a discontinuous Galerkin-finite-difference hybrid method
Recommended from our members
U-Pb zircon geochronology and depositional age models for the Upper Triassic Chinle Formation (Petrified Forest National Park, Arizona, USA): implications for Late Triassic paleoecological and paleoenvironmental change
The Upper Triassic Chinle Formation is a critical non-marine archive of low-paleolatitude biotic and environmental change in southwestern North America. The well-studied and highly fossiliferous Chinle strata at Petrified Forest National Park (PFNP), Arizona, preserve a biotic turnover event recorded by vertebrate and palynomorph fossils, which has been alternatively hypothesized to coincide with tectonically driven climate change or with the Manicouagan impact event at ca. 215.5 Ma. Previous outcrop-based geochronologic age constraints are difficult to put in an accurate stratigraphic framework because lateral facies changes and discontinuous outcrops allow for multiple interpretations. A major goal of the Colorado Plateau Coring Project (CPCP) was to retrieve a continuous record in unambiguous superposition designed to remedy this situation. We sampled the 520-m-long core 1A of the CPCP to develop an accurate age model in unquestionable superposition by combining U-Pb zircon ages and magnetostratigraphy. From 13 horizons of volcanic detritus-rich siltstone and sandstone, we screened up to ∼300 zircon crystals per sample using laser ablation−inductively coupled plasma−mass spectrometry and subsequently analyzed up to 19 crystals of the youngest age population using the chemical abrasion−isotope dilution−thermal ionization mass (CA-ID-TIMS) spectrometry method. These data provide new maximum depositional ages for the top of the Moenkopi Formation (ca. 241 Ma), the lower Blue Mesa Member (ca. 222 Ma), and the lower (ca. 218 to 217 Ma) and upper (ca. 213.5 Ma) Sonsela Member. The maximum depositional ages obtained for the upper Chinle Formation fall well within previously proposed age constraints, whereas the maximum depositional ages for the lower Chinle Formation are relatively younger than previously proposed ages from outcrop; however, core to outcrop stratigraphic correlations remain uncertain. By correlating our new ages with the magnetostratigraphy of the core, two feasible age model solutions can be proposed. Model 1 assumes that the youngest, coherent U-Pb age clusters of each sample are representative of the maximum depositional ages and are close to (227 Ma) in age, and hence the biotic turnover event cannot be correlated to the Carnian−Norian boundary but is rather a mid-Norian event. Our age models demonstrate the powers, but also the challenges, of integrating detrital CA-ID-TIMS ages with magnetostratigraphic data to properly interpret complex sedimentary sequences
Culinary communication practices:The role of retail spaces in producing field-specific cultural capital
Purpose: This chapter explores the practices underpinning the production of field-specific cultural capital at festivals, understood here as retail spaces that gather a plethora of distinct market actors. Methodology/Approach: This research presents evidence from an ethnographic study employing an interpretative paradigm and multiple data collection processes. The empirical research has been undertaken in the context of food festivals associated with the foodie taste regime. Findings: Three categories of practices that play a role in the production of field-specific cultural capital, namely representational, exchange, and experiential practices, are presented. Practical Implications: Our chapter provides recommendations for food festival organizers and participants who need to improve their practices when facing challenges such as increasing international competition and costs or declining sponsorship. Research Limitations/Implications: This chapter contributes to the growing body of field-level market analysis by showing how practices enabled by complex retail spaces contribute to the production of field-specific cultural capital. However, this chapter is limited by its focus on food festivals. Originality/Value of the Paper: This chapter theorizes how practices enable the acceleration and diversification of field-specific capital exchange, as well as its integration with other forms of capital
Mapping the absence : A theological critique of posthumanist influences in marketing and consumer research
In this study, we critically examine the ongoing adoption of various posthumanist influences into the fields of marketing and consumer research from a theological perspective. By conducting a theological-historical assessment, we propose that it is not posthuman notions of human/technology relations, nor their broader context in the emerging non-representational paradigms, that mark radically new disruptions in the continuing restructuring of the disciplines of marketing and consumer research. Instead, we argue that what is taking place is an implicit adherence to a contemporary form of age-old Christian dogma. As a radical conjecture, we thus propose that an identification of certain similarities between Christian dogma and the grounds for various posthumanist frameworks suggest that posthuman thought may well herald the global dissemination of a far more elusive, authoritarian, and hegemonic system than that which posthumanists typically claim to have abandoned. Consequently, we elaborate on implications to developments in marketing thought.Peer reviewe
A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring
Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss (3,69). Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops (13,36,51,80)
- …