857 resultados para Continuous improvements
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INTRODUCTION: Electroencephalography (EEG) has a central role in the outcome prognostication in subjects with anoxic/hypoxic encephalopathy following a cardiac arrest (CA). Continuous EEG monitoring (cEEG) has been consistently developed and studied; however, its yield as compared to repeated standard EEG (sEEG) is unknown. METHODS: We studied a prospective cohort of comatose adults treated with therapeutic hypothermia (TH) after a CA. cEEG data regarding background activity and epileptiform components were compared to two 20 minute sEEG extracted from the cEEG recording (one during TH, and one in early normothermia). RESULTS: In this cohort, 34 recordings were studied. During TH, the agreement between cEEG and sEEG was 97.1% (95% CI: 84.6 - 99.9%) for background discontinuity and reactivity evaluation, while it was 94.1% (95% CI 80.3 - 99.2%) regarding epileptiform activity. In early normothermia, we did not find any discrepancies. Thus, concordance was very good during TH (kappa 0.83), and optimal during normothermia (kappa=1). The median delay between CA and the first EEG reactivity testing was 18 hours (range: 4.75 - 25) for patients with perfect agreement and 10 hours (range: 5.75 - 10.5) for the three patients in whom there were discordant findings (P=0.02, Wilcoxon). CONCLUSION: Standard intermittent EEG has comparable performance than continuous EEG both for variables important for outcome prognostication (EEG reactivity) and identification of epileptiform transients in this relatively small sample of comatose survivors of CA. This finding has an important practical implication, especially for centers where EEG resources are limited.
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This work presents an alternative to generate continuous phase shift of sinusoidal signals based on the use of super harmonic injection locked oscillators (ILO). The proposed circuit is a second harmonic ILO with varactor diodes as tuning elements. In the locking state, by changing the varactor bias, a phase shift instead of a frequency shift is observed at the oscillator output. By combining two of these circuits, relative phases up to 90 could be achieved. Two prototypes of the circuit have been implemented and tested, a hybrid version working in the range of 200-300 MHz and a multichip module (MCM) version covering the 900¿1000 MHz band.
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INTRODUCTION: Continuous EEG (cEEG) is increasingly used to monitor brain function in neuro-ICU patients. However, its value in patients with coma after cardiac arrest (CA), particularly in the setting of therapeutic hypothermia (TH), is only beginning to be elucidated. The aim of this study was to examine whether cEEG performed during TH may predict outcome. METHODS: From April 2009 to April 2010, we prospectively studied 34 consecutive comatose patients treated with TH after CA who were monitored with cEEG, initiated during hypothermia and maintained after rewarming. EEG background reactivity to painful stimulation was tested. We analyzed the association between cEEG findings and neurologic outcome, assessed at 2 months with the Glasgow-Pittsburgh Cerebral Performance Categories (CPC). RESULTS: Continuous EEG recording was started 12 ± 6 hours after CA and lasted 30 ± 11 hours. Nonreactive cEEG background (12 of 15 (75%) among nonsurvivors versus none of 19 (0) survivors; P < 0.001) and prolonged discontinuous "burst-suppression" activity (11 of 15 (73%) versus none of 19; P < 0.001) were significantly associated with mortality. EEG seizures with absent background reactivity also differed significantly (seven of 15 (47%) versus none of 12 (0); P = 0.001). In patients with nonreactive background or seizures/epileptiform discharges on cEEG, no improvement was seen after TH. Nonreactive cEEG background during TH had a positive predictive value of 100% (95% confidence interval (CI), 74 to 100%) and a false-positive rate of 0 (95% CI, 0 to 18%) for mortality. All survivors had cEEG background reactivity, and the majority of them (14 (74%) of 19) had a favorable outcome (CPC 1 or 2). CONCLUSIONS: Continuous EEG monitoring showing a nonreactive or discontinuous background during TH is strongly associated with unfavorable outcome in patients with coma after CA. These data warrant larger studies to confirm the value of continuous EEG monitoring in predicting prognosis after CA and TH.
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Recent reports have indicated that 23.5 percent of the nation's highway bridges are structurally deficient and 17.7 percent are functionally obsolete. A significant number of these bridges are on the Iowa county road system. The objective of the investigation described in this report was to identify, review and evaluate replacement bridges currently being used by various counties in Iowa and surrounding states. Iowa county engineers, county engineers in neighboring states as well as private manufacturers of bridge components, and regional precad prestressed concrete manufacturers were contacted to determine the most common replacement bridge types being used. Depending upon the findings of the review, possible improvements and/or new replacement bridge systems were to be proposed. A questionnaire was developed and sent to county engineers in Iowa and several counties in surrounding states. The results of the questionnaire showed that the most common replacement bridges in Iowa are the continuous concrete slab and prestressed concrete bridges. The primary reason these types are used is because of the availability of standard designs and because of their ease of maintenance. Counties seldom construct these types of bridges using their own labor forces, but instead contract the work. However, county forces are used to construct steel stringer, precast reinforced concrete and timber bridges. In general, 69 percent of the counties indicate an ability and willingness to use their own forces to design and construct relatively short span bridges (i.e., 40 A or less) provided the construction procedures are relatively simple. Several unique replacement bridge types used in Iowa that are constructed by county forces are documented and presented in this report. Sufficient details are provided to allow county engineers to determine if some of these bridges could be used to resolve some of their own replacement bridge problems. Where possible, cost information has also been provided. Each of these bridge types were evaluated for various criteria (e.g., cost effectiveness, conformance to AASI-ITO standards, range of sizes, etc.) by a panel of four Iowa county engineers; a summary of this critique is included. After evaluating the questionnaire responses from the counties and evaluating the various bridge replacement concepts currently in use, one new bridge replacement concept and one modification of a current Iowa county bridge replacement concept were developed. Both of these concepts would utilize county labor forces.
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BACKGROUND: Intimal hyperplasia (IH) is a vascular remodeling process which often leads to failure of arterial bypass or hemodialysis access. Experimental and clinical work have provided insight in IH development; however, further studies under precise controlled conditions are required to improve therapeutic strategies to inhibit IH development. Ex vivo perfusion of human vessel segments under standardized hemodynamic conditions may provide an adequate experimental approach for this purpose. Therefore, chronically perfused venous segments were studied and compared to traditional static culture procedures with regard to functional and histomorphologic characteristics as well as gene expression. MATERIALS AND METHODS: Static vein culture allowing high tissue viability was performed as previously described. Ex vivo vein support system (EVVSS) was performed using a vein support system consisting of an incubator with a perfusion chamber and a pump. EVVSS allows vessel perfusion under continuous flow while maintaining controlled hemodynamic conditions. Each human saphenous vein was divided in two parts, one cultured in a Pyrex dish and the other part perfused in EVVSS for 14days. Testing of vasomotion, histomorphometry, expression of CD 31, Factor VIII, MIB 1, alpha-actin, and PAI-l were determined before and after 14days of either experimental conditions. RESULTS: Human venous segments cultured under traditional or perfused conditions exhibited similar IH after 14 days as shown by histomorphometry. Smooth-muscle cell (SMC) was preserved after chronic perfusion. Although integrity of both endothelial and smooth-muscle cells appears to be maintained in both culture conditions as confirmed by CD31, factor VIII, and alpha-actin expression, a few smooth-muscle cells in the media stained positive for factor VIII. Cell-proliferation marker MIB-1 was also detected in the two settings and PAI-1 mRNA expression and activity increased significantly after 14 days of culture and perfusion. CONCLUSION: This study demonstrates the feasibility to chronically perfuse human vessels under sterile conditions with preservation of cellular integrity and vascular contractility. To gain insights into the mechanisms leading to IH, it will now be possible to study vascular remodeling not only under static conditions but also in hemodynamic environment mimicking as closely as possible the flow conditions encountered in reconstructive vascular surgery.
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An equation for mean first-passage times of non-Markovian processes driven by colored noise is derived through an appropriate backward integro-differential equation. The equation is solved in a Bourret-like approximation. In a weak-noise bistable situation, non-Markovian effects are taken into account by an effective diffusion coefficient. In this situation, our results compare satisfactorily with other approaches and experimental data.
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The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Don’t Let a Contractor “Put the Fix in” on YOUR Home Repairs & Improvements!
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We apply the formalism of the continuous-time random walk to the study of financial data. The entire distribution of prices can be obtained once two auxiliary densities are known. These are the probability densities for the pausing time between successive jumps and the corresponding probability density for the magnitude of a jump. We have applied the formalism to data on the U.S. dollardeutsche mark future exchange, finding good agreement between theory and the observed data.
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We investigate the phase transition in a strongly disordered short-range three-spin interaction model characterized by the absence of time-reversal symmetry in the Hamiltonian. In the mean-field limit the model is well described by the Adam-Gibbs-DiMarzio scenario for the glass transition; however, in the short-range case this picture turns out to be modified. The model presents a finite temperature continuous phase transition characterized by a divergent spin-glass susceptibility and a negative specific-heat exponent. We expect the nature of the transition in this three-spin model to be the same as the transition in the Edwards-Anderson model in a magnetic field, with the advantage that the strong crossover effects present in the latter case are absent.
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The usual development of the continuous-time random walk (CTRW) assumes that jumps and time intervals are a two-dimensional set of independent and identically distributed random variables. In this paper, we address the theoretical setting of nonindependent CTRWs where consecutive jumps and/or time intervals are correlated. An exact solution to the problem is obtained for the special but relevant case in which the correlation solely depends on the signs of consecutive jumps. Even in this simple case, some interesting features arise, such as transitions from unimodal to bimodal distributions due to correlation. We also develop the necessary analytical techniques and approximations to handle more general situations that can appear in practice.
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FHWA and the Iowa Department of Transportation are proposing geometric and capacity improvements to the Interstate 29 and Interstate 80 mainline in Segment 3 and the I-80/I-29 East System interchange, the South Expressway interchange, the U.S. Highway 275 interchange, and the Madison Avenue interchange to to safely and efficiently of transportation in the City of Council Bluffs, the Iowa DOT is also proposing to eliminate several railroad alignments and to develop new, consolidated tracks in Segment 3.
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The Iowa Department of Transportation (Iowa DOT), Nebraska Department of Roads (NDOR), and the Federal Highway Administration (FHWA) are proposing to improve the interstate system around Council Bluffs with improvements extending across the Missouri River on I-80 to east of the I-480 interchange in Omaha, Nebraska, see Figure 1-1. The study considers long-term, broad-based transportation improvements along I-80, I-29, and I-480, including approximately 18 mainline miles of interstate and 14 interchanges (3 system1, 11 service), that would add capacity and correct functional issues along the mainline and interchanges and upgrade the I-80 Missouri River Crossing. These improvements, once implemented, would bring the segments of I-80 and I-29 up to current engineering standards and modernize the roadway to accommodate future traffic needs. In 2001, Iowa DOT and FHWA initiated the Council Bluffs Interstate System (CBIS) Improvements Project. The agencies concluded that the environmental study process would be conducted in two stages; that is, a tiered approach would be applied. The project is being conducted pursuant to the National Environmental Policy Act (NEPA) regulations issued by the Council on Environmental Quality (CEQ), 40 Code of Federal Regulations (CFR) Part 1502.20, and FHWA 23 CFR Part 771.111, that permit tiering for large, complex NEPA studies. Tier 1 is an examination of the overall interstate system improvement needs, including a clear explanation of the area’s transportation needs, a study of alternatives to satisfy them, and broad consideration of potential environmental and social impacts. The Tier 1 evaluation is at a sufficient level of engineering and environmental detail to assist decision makers in selecting a preferred transportation strategy. Tier 1 includes preparation of a draft and final Environmental Impact Statement (EIS) that would disclose the potential environmental and social effects (evaluated at a planning level that considers a variety of conceptual designs) of the proposed improvements. The final EIS will conclude with a Record of Decision (ROD) that states the preferred plan for improvements to be implemented. Essentially, the Tier 1 document will establish the planning framework for the needed improvements. Because the scope of the overall system improvements is large, the interstate improvements would be implemented as a series of individual projects that fit into the overall planning framework. The Tier 1 Area of Potential Impact, which is discussed in detail in Section 4 is an alternative that considers a combination of the most reasonable concepts that have been developed, buffered by approximately 100 or more feet to ensure that any Tier 2 design modifications would remain inside the outer boundary.
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The Federal Highway Administration (FHWA) approves the selection of the Reconstruction of All or Part of the Interstate (Construction Alternative) as the Preferred Alternative to provide improvements to the interstate system in the Omaha/Council Bluffs metropolitan area, extending across the Missouri River on Interstate 80 to east of the Interstate 480 interchange in Omaha, Nebraska. The study considered long-term, broad-based transportation improvements along Interstate I-29 (I-29), I-80, and I-480, including approximately 18 mainline miles of interstate and 14 interchanges (3 system, 11 service), that would add capacity and correct functional issues along the mainline and interchanges and upgrade the I-80 Missouri River Crossing. FHWA also approves the decisions to provide full access between West Broadway and I-29, design the I-80/I-29 overlap section as a dual-divided freeway, and locating the new I-80 Missouri River Bridge north of the existing bridge. Improvements to the interstate system, once implemented, would bring the segments of I-80 and I-29 (see Figure 1) up to current engineering standards and accommodate future traffic needs. This Record of Decision (ROD) concludes Tier 1 of the Council Bluffs Interstate System (CBIS) Improvements Project. Tier 1 included an examination of the area’s transportation needs, a study of alternatives to satisfy them, and broad consideration of potential environmental and social impacts. The Tier 1 evaluation consisted of a sufficient level of engineering and environmental detail to assist decision makers in selecting a preferred transportation strategy. During Tier 1 a Draft EIS (FHWA-IA- EIS-04-01D) was developed which was approved by FHWA, Iowa DOT, and Nebraska Department of Roads (NDOR) in November 2004 with comments accepted through March 15, 2005. The Draft EIS summarized the alternatives that were considered to address the transportation needs around Council Bluffs; identified reconstruction of all or part of the interstate, the “Construction Alternative,” as the Preferred Alternative; identified three system-level decisions that needed to be made at the Tier 1 level; and invited comment on the issues. The Final EIS (FHWA-IA- EIS-04-01F) further documented the Construction Alternative as the Preferred Alternative and identified the recommended decisions for the three system level decisions that needed to be made in Tier 1. This ROD defines the Selected Alternative determined in the Tier 1 studies.
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The continuous-time random walk (CTRW) formalism can be adapted to encompass stochastic processes with memory. In this paper we will show how the random combination of two different unbiased CTRWs can give rise to a process with clear drift, if one of them is a CTRW with memory. If one identifies the other one as noise, the effect can be thought of as a kind of stochastic resonance. The ultimate origin of this phenomenon is the same as that of the Parrondo paradox in game theory.