194 research outputs found

    Effect of Size Distribution in Estimating b[ext], b[scat], and b[abs] from Atmospheric Pollutant Measurements

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    Coefficients of extinction, scattering, and absorption are calculated using an arbritratry size distribution and physical and chemical aerosol data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) and the Eastern Fine Particulate Visibility Network (EFPVN)data systems. Calculated results are compared with the measured values using linear regression analysis and correlation coefficient. The results from both data sets indicate that fairly accurate (±50%)estimates of the coefficients are possible when the size distribution is in the range of mean diameter 0.2-0.4 with geometric standard deviation 1.2-1.5Master of Science in Environmental Engineerin

    A new integrable generalization of the Korteweg - de Vries equation

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    A new integrable sixth-order nonlinear wave equation is discovered by means of the Painleve analysis, which is equivalent to the Korteweg - de Vries equation with a source. A Lax representation and a Backlund self-transformation are found of the new equation, and its travelling wave solutions and generalized symmetries are studied.Comment: 13 pages, 2 figure

    Concordancia entre el decir y el hacer

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    La autora hace un inteligente planteamiento de la crisis social como repercusión del desplazamiento a la nueva economía mundial. Abre el panorama de los escenarios posibles, sin descuidar el aspecto laboral, tan poco atendido en los tiempos actuales

    Effect of Wiring and Cabling Topologies on the Performance of Distributed MIMO OFDM VLC Systems

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    Since most indoor spaces have multiple luminaires for illumination, for visible light communication (VLC) systems, multiple-input multiple-output (MIMO) communication emerges as a natural solution to improve the data rates and/or the link reliability. The existing works on MIMO VLC systems, however, overlook the characteristics of the lighting infrastructure and the luminaire design, which might have implications for the VLC system design. A luminaire typically consists of multiple LED chips. The wiring topology refers to how the LED chips are connected within the luminaire. The cabling topology, on the other hand, refers to how the luminaires are connected to the communication access point (AP). Based on the type and length of cabling and wiring, significant delays can be introduced, which should be taken into account in channel modeling. In this paper, we adopt the non-sequential ray tracing to model the distributed MIMO VLC channels for various practical wiring and cabling topologies. Based on the developed channel models, we provide a comparative performance analysis of repetition coding (RC), spatial multiplexing (SMUX), and spatial modulation (SMOD) MIMO modes. Our results quantify the effect of wiring/cabling delays and provide insights into the optimized design of lighting infrastructure and luminaires for the support of VLC as an add-on service...

    Anti-EBNA1 IgG titre is not associated with fatigue in multiple sclerosis patients

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    Introduction. Fatigue is the most frequent symptom in multiple sclerosis (MS), although it is still poorly understood due to its complexity and subjective nature. There is an urgent need to identify reliable biomarkers to improve disease prognosis and therapeutic strategies. Epstein-Barr virus (EBV) is the major environmental risk factor associated with MS aetiology, and trials with EBV-targeted T cell therapies have reduced fatigue severity in MS patients. Aim of the study. We investigated whether the serum amount of immunoglobulin (Ig)G-specific for EBV antigens could be a suitable prognostic marker for the assessment of MS-related fatigue. Material and methods. A total of 194 MS patients were enrolled. We quantified EBV nuclear antigen 1 (EBNA1) and EBV viral capsid antigen (VCA) immunoglobulin (Ig) G levels and B cell-activating factor of the tumour necrosis factor family (BAFF) concentration in the serum of patients with relapsing-remitting MS (RRMS) and chronic progressive MS (CPMS), and we analysed their correlation with aspects of fatigue and other clinical disease parameters. Results. A complete EBV seropositivity could be detected in our cohort. After adjusting for confounding variables and covariates, neither EBNA1 nor VCA antibody titres were associated with levels of fatigue, sleepiness, depression, or with any of the clinical values such as expanded disability status scale, lesion count, annual relapse rate, or disease duration. However, patients with RRMS had significantly higher EBNA1 IgG titre than those with CPMS, whereas this was not the case under therapies targeting CD20+ cells. BAFF levels in serum were inversely proportional to anti-EBNA1 IgG. Conclusions and clinical implications. Our results show that EBNA1 IgG titre is not associated with the presence or level of fatigue. Whether the increased EBNA1 titre in RRMS plays a direct role in disease progression, or is only a consequence of excessive B cell activation, remains to be answered in future studies

    Protective efficiacy of taurine against pulmonary edema progression: experimental study

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    Re-expansion pulmonary edema (RPE) is an acute, rare and potentially lethal complication [1,2]. Its beginning is sudden and dramatic. The mechanism is not yet fully understood [1]. Some authors suggest that it may occur after rapid re-inflation of a collapsed lung [1]. It was reported by other authors that it may relate to surfactant depletion or may result from hypoxic capillary damage, leading to increased capillary permeability [1,3]. In RPE, unilateral lung injury is initiated by cytotoxic oxygen metabolites and temporally associated with an influx of polymorphonuclear neutrophils [1]. These toxic oxygen products are the results of re-oxygenation of a collapsed lung. Treatment of re-expansion pulmonary edema is basically preventive [4]

    Protective efficiacy of taurine against pulmonary edema progression: experimental study

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    Re-expansion pulmonary edema (RPE) is an acute, rare and potentially lethal complication [1,2]. Its beginning is sudden and dramatic. The mechanism is not yet fully understood [1]. Some authors suggest that it may occur after rapid re-inflation of a collapsed lung [1]. It was reported by other authors that it may relate to surfactant depletion or may result from hypoxic capillary damage, leading to increased capillary permeability [1,3]. In RPE, unilateral lung injury is initiated by cytotoxic oxygen metabolites and temporally associated with an influx of polymorphonuclear neutrophils [1]. These toxic oxygen products are the results of re-oxygenation of a collapsed lung. Treatment of re-expansion pulmonary edema is basically preventive [4]

    Factors affecting the outcome of surgically treated non-iatrogenic traumatic cervical esophageal perforation: 28 years experience at a single center

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    <p>Abstract</p> <p>Background</p> <p>We reviewed our experience with non-iatrogenic traumatic cervical esophageal perforations, paying particular attention to factors affecting the outcome of such cases.</p> <p>Methods</p> <p>In total, 30 patients treated surgically between 1980 and 2008 for non-iatrogenic traumatic cervical esophageal perforation in our clinic were reviewed.</p> <p>Results</p> <p>There were 25 male and 5 female patients with a median age of 27.5 years. The type of injury was external trauma in 21 (70%) patients and endoluminal injury in the remaining 9 (30%) patients. The mechanism of injury was gunshot in 16 patients, stabbing in 4, falling in 1 (extraluminal injury), and foreign body in 9 (endoluminal injuries). The overall mortality rate was 16.6% (5/30). The mortality rate for extraluminal injuries was 19%, and for endoluminal injuries was 11.1%. Mortality in patients treated within 24 h of sustaining injury was substantially less than in those for whom diagnosis and treatment were delayed (12.5 and 21.4%, respectively). The mortality rate was 33.3% (3/9) for patients with tracheal injuries and 9.5% (2/21) for those without tracheal injuries.</p> <p>Conclusions</p> <p>A treatment delay greater than 24 h, the presence of tracheal injury, or extraluminal perforation significantly affected the outcome of surgically treated non iatrogenic traumatic cervical esophageal perforation.</p
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