739 research outputs found
Bioterrorism and U.S. domestic preparedness: Bureaucratic fragmentation and American vulnerability
This article takes a closer look at the United Statesâ domestic preparedness program. Beginning in the mid-1990s, the domestic preparedness program has served as the United Statesâ disaster response and management option in the case of a biological or chemical weapons attack. In its early years, the program focused solely on chemical weapons, but eventually expanded to cover the threat of biological weapons as well. The program, however, is fragmented, leaving authority in the hands of over a dozen different agencies. This leaves the authorities, capabilities, and resources needed to effectively implement the program divided across multiple bureaucracies. In addition, the program is essentially made up of a series of legislative initiatives, causing it to be desperately uncoordinated. Given this organizational fragmentation, we ask: does the domestic preparedness program really prepare the United States for a biological weapons attack
Hallmarks of Furman\u27s 2011 retirees: Commitment, foresight and integrity
At the close of the 2010-11 academic year, Furman said farewell to five faculty members who worked at the university for a combined 173 years. As a tribute to the retirees, all of whom have been awarded emeritus status, Furman magazine asked departmental colleagues (and, in two cases, former students) to comment on their careers and contributions
Multi-transmission-line-beam interactive system
We construct here a Lagrangian field formulation for a system consisting of
an electron beam interacting with a slow-wave structure modeled by a possibly
non-uniform multiple transmission line (MTL). In the case of a single line we
recover the linear model of a traveling wave tube (TWT) due to J.R. Pierce.
Since a properly chosen MTL can approximate a real waveguide structure with any
desired accuracy, the proposed model can be used in particular for design
optimization. Furthermore, the Lagrangian formulation provides for: (i) a clear
identification of the mathematical source of amplification, (ii) exact
expressions for the conserved energy and its flux distributions obtained from
the Noether theorem. In the case of uniform MTLs we carry out an exhaustive
analysis of eigenmodes and find sharp conditions on the parameters of the
system to provide for amplifying regimes
Multi-scale modeling study of the source contributions to near-surface ozone and sulfur oxides levels over California during the ARCTAS-CARB period
Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire emissions to SC O3 levels. California biogenic and fire emissions contribute 3â4 ppb to near-surface O3 over SC, with larger contributions to other regions in CA. During a long-range transport event from Asia starting from 22 June, high SOx levels (up to ~0.7 ppb of SO2 and ~1.3 ppb of SO4) is observed above ~6 km, but they did not affect CA surface air quality. The elevated SOx observed at 1â4 km is estimated to enhance surface SOx over SC by ~0.25 ppb (upper limit) on ~24 June. The near-surface SOx levels over SC during the flight week are attributed mostly to local emissions. Two anthropogenic SOx emission inventories (EIs) from the California Air Resources Board (CARB) and the US Environmental Protection Agency (EPA) are compared and applied in 60 km and 12 km chemical transport simulations, and the results are compared withobservations. The CARB EI shows improvements over the National Emission Inventory (NEI) by EPA, but generally underestimates surface SC SOx by about a factor of two. Adjoint sensitivity analysis indicated that SO2 levels at 00:00 UTC (17:00 local time) at six SC surface sites were influenced by previous day maritime emissions over the ocean, the terrestrial emissions over nearby urban areas, and by transported SO2 from the north through both terrestrial and maritime areas. Overall maritime emissions contribute 10â70% of SO2 and 20â60% fine SO4 on-shore and over the most terrestrial areas, with contributions decreasing with in-land distance from the coast. Maritime emissions also modify the photochemical environment, shifting O3 production over coastal SC to more VOC-limited conditions. These suggest an important role for shipping emission controls in reducing fine particle and O3concentrations in SC
952-30 Left Ventricular Ejection Performance Improves Late After Aortic Valve Replacement in Patients with Aortic Stenosis and Reduced Ejection Fraction
To assess the time course and magnitude of change in left ventricular (LV) wall stress and ejection performance indices, 24 patients undergoing aortic valve replacement (AVR) for aortic stenosis were prospectively evaluated. Each patient underwent resting radionuclide angiography (RNA), echocardiography, and cardiac catheterization (high fidelity pressure) before AVR, then RNA and echocardiogram at one week and six months after AVR. Patients were stratified by preoperative ejection fraction (EF) into reduced EF (<50%) and normal EF (â„50%) groups.Pre-operatively, peak positive dp/dt was lower in the reduced EF group (1300 vs 1700mmHg/sec, p=0.035), and wall stress was elevated similarly in both groups (p=NS).Temporal Relationships of EF and Wall StressPre-op1 Week6 MosNormal EF (n=14)Mean Ejection Fraction (%)666468Mean Wall Stress (dyne/cm2Ă103)623444Reduced EF (n=10)Mean Ejection Fraction (%)383757Mean Wall Stress (dyne/cm2Ă103)785261Wall stress was reduced at one week post-operatively (p<0.005) in both groups. Ejection fraction remained depressed in the reduced EF group. By six months, however, EF had dramatically improved in the reduced EF group (p=0.002).ConclusionIn patients with LV dysfunction, EF remains low one week after AVR despite rectification of afterload mismatch. At six months, however, ejection performance improves. Therefore, when measured by ejection phase indices, the surgical benefit from AVR is not evident until late post-operatively
Preliminary study of the variations on the spatio-temporal distribution of a potentially exploitable species (Patagonotothen spp.) in the southwest Atlantic, using GIS techniques
The genus Patagonotothen is the most common Nototheniid on the Patagonian Shelf and slope and is part of the by-catch species in the bottom trawl fisheries. This paper presents preliminary results from the EC CRAFT project âPromoting higher added value to a finfish species rejected to seaâ, aiming to develop the research and the technology necessary to promote higher added value to fishing activity by taking profit from a finfish species (Rockcod, Patagonotothen spp.)
not known to consumers and currently discarded by the EU fishing fleet operating in the South West Atlantic in order to supply the EU seafood industry with a good quality raw material for human food manufacturing. Historical fishery data series (26 168 commercial hauls of which 12 745 were positive), including effort, catches and discards, as well as biological and environmental information, from 1988 onwards was used to describe and quantify patterns and spatio-temporal changes in the rockcod fishery. These data was collected by scientific observers on board commercial vessels.GIS analysis was carried out in order to study the seasonal geographical changes in the distribution of abundance, SST and densities calculated from CPUE. Fishery and environmental data as well as SST data derived from the NOAA Advanced Very
High Resolution Radiometer (AVHRR), were analysed in order to find monthly variations in
spatial and depth distribution of Patagonotothen spp. Preliminary results demonstrated that, within areas of occurrence, there are significant correlations between fish abundance (CPUE), the oceanographic conditions of the area (SST gradients) and depth in certain months
A prognostic model integrating PET-derived metrics and image texture analyses with clinical risk factors from GOYA
Image texture analysis (radiomics) uses radiographic images to quantify characteristics that may identify tumour heterogeneity and associated patient outcomes. Using fluoroâdeoxyâglucose positron emission tomography/computed tomography (FDGâPET/CT)âderived data, including quantitative metrics, image texture analysis and other clinical risk factors, we aimed to develop a prognostic model that predicts survival in patients with previously untreated diffuse large Bâcell lymphoma (DLBCL) from GOYA (NCT01287741). Image texture features and clinical risk factors were combined into a random forest model and compared with the international prognostic index (IPI) for DLBCL based on progressionâfree survival (PFS) and overall survival (OS) predictions. Baseline FDGâPET scans were available for 1263 patients, 832 patients of these were cellâofâorigin (COO)âevaluable. Patients were stratified by IPI or radiomics features plus clinical risk factors into lowâ, intermediateâ and highârisk groups. The random forest model with COO subgroups identified a clearer highârisk population (45% 2âyear PFS [95% confidence interval (CI) 40%â52%]; 65% 2âyear OS [95% CI 59%â71%]) than the IPI (58% 2âyear PFS [95% CI 50%â67%]; 69% 2âyear OS [95% CI 62%â77%]). This study confirms that standard clinical risk factors can be combined with PETâderived image texture features to provide an improved prognostic model predicting survival in untreated DLBCL
A Workflows Roadmap for the Geosciences
The EarthCube Workflows Community Group was formed in March 2012 as part of the NSF EarthCube initiative in response to initial discussions in EarthCube that occurred during 2011. Workflows are used to manage complex computations that have many steps or use large data. Workflow systems assist scientists to select models appropriate for their data, configure them with appropriate parameters, and execute them efficiently. The EarthCube community saw great value in workflow technologies for the future of geosciences. The goal of the EarthCube Workflows Community Group was to begin to elicit requirements for workflows in geosciences, ascertain the state of the art and current practices, identify current gaps in both the use of and capabilities of current workflow systems in the earth sciences through use case studies, and identify grand challenges for the next decade along with the possible paths to addressing those challenges. The group was asked to produce a roadmap for workflows in geosciences. Three other Community Groups were formed (Data, Semantics and Ontologies, and Governance), and each was asked to create a roadmap in their area.
The group held a series of virtual and face-to-face workshops to solicit participation from the geosciences community and other relevant researchers. The EarthCube Workflows Community Group set up a public web site where all their activities were made open for participation from the community and all documents were posted for public access and editing (https://sites.google.com/site/earthcubeworkflow/). Presentations and discussions were recorded and posted on the site. A key result of the work of the EarthCube Workflows Community Group activities in Spring and Summer 2012 was the creation of a workflows roadmap for the geosciences. An initial roadmap document for the EarthCube community that was first released in June 2012 and presented to the EarthCube community. A revised roadmap was delivered to the community in August 2012. The roadmap serves as a living document created as a group effort with provisions and a process to update and extend it over time.This document represents the final roadmap of the NSF EarthCube Community Group for workflows in the geosciences. Community feedback is always welcome, as the roadmap will be revised and extended while EarthCube activities continue.This work was supported through National Science Foundation under grant # EAR-1238216 as part of the NSF EarthCube initiative. EarthCube is an innovative and longterm cross-directorate initiative of the US National Science Foundation
Low recurrence rate of a two-layered closure repair for primary and recurrent midline incisional hernia without mesh
Background: Incisional hernia is a serious complication after abdominal surgery and occurs in 11-23% of laparotomies. Repair can be done, for instance, with a direct suture technique, but recurrence rates are high. Recent literature advises the use of mesh repair. In contrast to this development, we studied the use of a direct suture repair in a separate layer technique. The objective of this retrospective observational study is to assess the outcomes (recurrences and complications) of a two-layered open closure repair for primary and recurrent midline incisional hernia without the use of mesh. Methods: In an observational retrospective cohort study, we analysed the hospital and outpatient records of 77 consecutive patients who underwent surgery for a primary or recurrent incisional hernia between 1st May 2002 and 8th November 2006. The repair consisted of separate continuous suturing of the anterior and posterior fascia, including the rectus muscle, after extensive intra-abdominal adhesiolysis. Results: Forty-one men (53.2%) and 36 women (46.8%) underwent surgery. Sixty-three operations (81.8%) were primary repairs and 14 (18.2%) were repairs for a recurrent incisional hernia. Of the 66 patients, on physical examination, three had a recurrence (4.5%) after an average follow-up of 2.6 years. The 30-day postoperative mortality was 1.1%. Wound infection was seen in five patients (6.5%). Conclusions: A two-layered suture repair for primary and recurrent incisional hernia repair without mesh with extensive adhesiolysis was associated with a recurrence rate comparable to mesh repair and had an acceptable complication rate
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