bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Convective Initiation and Storm Evolution on 12 June 2002 during IHOP_2002. Part I: Control Simulation and Sensitivity Experiments
Authors: Liu Haixia , Xue Ming 
Published: July 2008

Abstract
The 12–13 June 2002 convective initiation case from the International H2O Project (IHOP_2002) field experiment over the central Great Plains of the United States is simulated numerically with the Advanced Regional Prediction System (ARPS) at 3-km horizontal resolution. The case involves a developing mesoscale cyclone, a dryline extending from a low center southwestward with a cold front closely behind, which intercepts the midsection of the dryline, and an outflow boundary stretching eastward from the low center resulting from earlier mesoscale convection. Convective initiation occurred in the afternoon at several locations along and near the dryline or near the outflow boundary, but was not captured by the most intensive deployment of observation instruments during the field experiment, which focused instead on the dryline–outflow boundary intersection point.
Standard and special surface and upper-air observations collected during the field experiment are assimilated into the ARPS at hourly intervals in a 6-h preforecast period in the control experiment. This experiment captured the initiation of four groups of convective cells rather well, with timing errors ranging between 10 and 100 min and location errors ranging between 5 and 60 km. The general processes of convective initiation are discussed. Interestingly, a secondary initiation of cells due to the collision between the main outflow boundary and the gust fronts developing out of model-predicted convection earlier is also captured accurately about 7 h into the prediction. The organization of cells into a squall line after 7 h is reproduced less well.
A set of sensitivity experiments is performed in which the impact of assimilating nonstandard data gathered by IHOP_2002, and the length and interval of the data assimilation are examined. Overall, the control experiment that assimilated the most data produced the best forecast although some of the other experiments did better in some aspects, including the timing and location of the initiation of some of the cell groups. Possible reasons for the latter results are suggested. The lateral boundary locations are also found to have significant impacts on the initiation and subsequent evolution of convection, by affecting the interior flow response and/or feeding in more accurate observation information through the boundary, as available gridded analyses from a mesoscale operational model were used as the boundary condition. Another experiment examines the impact of the vertical correlation scale in the analysis scheme on the cold pool analysis and the subsequent forecast. A companion paper will analyze in more detail the process and mechanism of convective initiation, based on the results of a nested 1-km forecast.
Potential Vorticity Regression and Its Relationship to Dynamical Piecewise Inversion
Authors: Gombos Daniel , Hansen James A. 
Published: July 2008

Abstract
Hakim and Torn (HT) presented a statistical piecewise potential vorticity (PV) regression technique that uses flow-dependent analysis covariances from an ensemble square root filter to statistically infer the relationship between the PV and state fields. This paper illustrates that the PV perturbation effectively regressed by HT’s regression is the projection of the PV perturbation onto the ensemble PV anomalies that define the regression operator. It is shown that the piecewise PV inversion of this effective PV perturbation via the technique presented in Davis and Emanuel yields nearly identical heights to those from an HT regression performed in the subspace of the leading PV singular vectors.
Third-Order Finite-Difference Schemes on Icosahedral-Type Grids on the Sphere
Authors: Steppeler J. , Rípodas P. , Jonkheid B. , Thomas S. 
Published: July 2008

Abstract
A practical method is proposed to achieve high-order finite-difference schemes on grids that are quasi-homogeneous on the sphere. A family of grids is used that are characterized by the parameter NP, which can take on values of 3, 4, and 5, etc. The parameter NP is the number of grid patches meeting at the Poles. For NP = 3 the cube sphere grid is obtained and for NP = 5 the icosahedron is obtained. While the grid construction method is valid for all values of NP, the tests performed in this paper concern only the case NP = 5 (i.e., the icosahedron). For each of the rhomboidal patches, the grid is created by connecting points on opposing sides of the rhomboid by great circles. This offers the possibility to obtain derivatives for a line of grid points along a great circle in the classical way. Therefore, it becomes possible to use well-known spatial discretizations from limited-area models. Local models can be transferred to the sphere with rather limited effort. The method was tested using the fourth-order Runge–Kutta integration method and fourth-order spatial differencing. At patch limits, boundary values are obtained using third-order serendipity interpolation, giving the scheme an overall space–time accuracy of 3. The serendipity interpolation is quite efficient. Third-order interpolation in two dimensions is achieved by a set of linear interpolations and a number of function evaluations. All coefficients can be precomputed. The third-order convergence is demonstrated by numerical experiments using Williamson’s test cases 2 and 6.
Use of the Information Content in Satellite Measurements for an Efficient Interface to Data Assimilation
Authors: Migliorini Stefano , Piccolo Chiara , Rodgers Clive D. 
Published: July 2008

Abstract
Satellite observations are the most assimilated data type by operational meteorological centers. Spaceborne instruments can make measurements all over the globe and provide observations for assimilation even where the coverage of other data is poor. It is therefore most important that such observations, which are only indirectly related to the state of the atmosphere, are assimilated as optimally as possible. In this study, a detailed characterization of both retrievals and observed radiances for assimilation is provided, along with an error analysis. A method for assimilating remote sounding data while preserving its information content is presented. The main features of the technique are as follows: (i) the retrieval–forecast error cross covariance is removed even when the retrieval is severely constrained by a priori information, (ii) the radiative transfer calculations for radiance assimilation are done offline, and (iii) the number of assimilated quantities per observation is reduced to the number of effective degrees of freedom in the observation.
Cloud-Resolving Modeling of Deep Convection during KWAJEX. Part I: Comparison to TRMM Satellite and Ground-Based Radar Observations
Authors: Li Yaping , Zipser Edward J. , Krueger Steven K. , Zulauf Mike A. 
Published: July 2008

Abstract
A global TRMM database of tropical cloud system precipitation features (PFs), which provides useful observational constraints on cloud system properties, is used to evaluate the bulk microphysics schemes in a cloud-resolving model (CRM). The simulation of the Mesoscale Convective System (MCS) of 11–12 August 1999 during the Kwajalein Experiment (KWAJEX) is executed using the 3D University of Utah CRM, which employs a one-moment bulk, three-ice category microphysical parameterization. The simulated precipitation features are compared with climatological “norms” for Kwajalein locations from the TRMM PF database to evaluate the precipitation microphysics of the cloud model simulation. The model-simulated reflectivities are also compared with vertical profiles of radar reflectivity obtained from a ground-based precipitation radar.
Comparison of simulation results with the TRMM observation statistics indicates that the model tends to underestimate microwave brightness temperatures at ice-scattering frequencies and overestimate radar reflectivities, especially for those associated with larger ice particles. The differences between the statistics of KWAJEX simulation and available ground-based precipitation radar observations are relatively small at the levels below 5 km. Above 6 km, the differences increase with height and reach a maximum near 9 km. The simulated radar reflectivities are statistically 5–13 dBZ higher than those from radar observations at levels between 7 and 10.5 km, where graupel is the dominant simulated ice species. The largest graupel mixing ratios, as high as 8 g kg−1, are the most likely reason for the unrealistically high simulated radar reflectivity. Comparison of model-simulated graupel mixing ratio with available microphysics data from the Citation aircraft indicates that the model overestimates graupel content at the level the Citation flew (about 6.4 km).
Using Teleconnections to Predict Wildfires in Mississippi
Authors: Dixon P. Grady , Goodrich Gregory B. , Cooke William H. 
Published: July 2008

Abstract
Previous wildfire research in the United States has been focused primarily on the western states. Much of this research has discovered relationships between wildfire variability and atmospheric teleconnections. Thus far, few published projects have addressed the effects of various teleconnections on wildfire in the southeastern United States. Index values for the El Niño–Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Pacific decadal oscillation (PDO), and Pacific–North American (PNA) pattern are all tested for relationships with fire variables in the state of Mississippi. Each of the indices displays significant correlations with wildfire occurrence and/or size in Mississippi. The findings of this research suggest that it might be feasible to create predictive fire-risk models for the southeastern United States based on the combination of these teleconnection indices.
Study of the Value of Corrected Ejection Fraction in the Evaluation of Left Ventricular Function in Patients with Mitral or Aortic Regurgitation
Authors: Abd-El-Aziz Tarek A. , Frere Abd-El-Fattah H. , Khalil Tarek S. , Mansour Kamal S. , Abd-El-Hamid Akram F. , Abd-El-Barry Khalid H. 
Published: July 2008

Evaluation of left ventricular function in the presence of valvular regurgitation is still a clinical problem because ejection phase indices including ejection fraction are heavily dependent on preload and afterload and cannot be regarded as reliable indices of contrac tility in diseases associated with altered loading conditions. The authors attempted to evaluate the usefulness of the new index-corrected ejection fraction in the evaluation of left ventricular (LV) function in patients with chronic mitral (MR) or aortic regurgitation (AR). The study included 21 patients with chronic severe MR (11 patients) and AR (10 patients) with a mean age of 18 years. All patients underwent valve replacement or repair. Echo Doppler study was performed preoperatively and postoperatively and included measurement of the following LV parameters: end-diastolic dimension (EDD), end-diastolic volume (EDV), end-systolic dimension (ESD), end-systolic volume (ESV), ejection fraction (EF), systolic blood pressure/end-systolic dimension (SBP/ESD); also mitral and aortic stroke volume were calculated cross-sectional area (CSA) x time velocity integral TVI. Corrected ejection fraction (EFc) was derived from the following equation: ( continued on next page) The mean preoperative EFc did not change significantly after surgical correction of mitral or aortic regurgitation. Preoperative EFc did not show significant difference compared with postoperative EF in the two groups. Preoperative EFc correlated significantly with other preoperative and postoperative indices of LV function. Postoperative EFc showed very close correlation with other postoperative parameters. Thus, using the new index-corrected ejection fraction in the assessment of LV function in patients with mitral or aortic regurgitation has several advantages: Noninvasive, inde pendent of loading changes, helpful in predicting the immediate postoperative clinical course, and a reliable index for evaluation of LV systolic function preoperatively and postoperatively.
Pressure and Microcirculatory Effects of Treatment with Lercanidipine in Hypertensive Patients and in Vascular Patients with Hypertension
Authors: Incandela L. , Ledda A. , De Sanctis M.T. , Steigerwalt R. , Pellegrini L. , Bucci M. , Belcaro G. , Ciccarelli R. , Cesarone M.R. 
Published: July 2008

The aim of this study was to evaluate the macrocirculatory and microcirculatory effects of treatment with lercanidipine, a new antihypertensive agent acting both on blood pressure and microcirculation in patients with moderate essential hypertension and without vascular disease and in patient with hypertension and vascular disease. In hypertensive subjects target-organ damage associated with high blood pressure may now be objectively documented by noninvasive tests. These alterations constitute a model to evaluate not only the pressure effects of antihypertensive treatment but also the normalization of the peripheral microcirculatory network. With color duplex scanning, flow velocity in the central retinal artery and retinal flow velocity can be measured and with use of laser-Doppler-flowmetry, it is also possible to evaluate microcirculation alterations in hypertensive subjects. These evaluation methods are completely noninvasive and may be used to assess the microcirculatory effects of antihypertensive drugs.
Neutralization of Prostaglandin E1 Intravenous Solution Reduces Infusion Phlebitis
Authors: Hatori Nobuo , Shimizu Masafumi , Yoshizu Hiroshi , Segawa Daisuke , Kimura Tamizou , Iizuka Yasuhiro , Tanaka Susumu , Fujita Masanori 
Published: July 2008

Previous studies have shown moderate or severe phlebitis at the site of venipuncture in some patients who receiving prostaglandin E1 (PGE1) infusion therapy. Such phlebitis is sometimes severe enough to necessitate the cessation of PGE1 therapy. This study investigated how to continue PGE1 infusion therapy for 3 weeks with tolerable phlebitis. Although a 60 μg dose of PGE1 is usually dissolved in 500 mL of fluid to avoid phlebitis, we used 200 mL to prevent volume overload. This PGE1 solution was neutralized to pH 7.4 with 4 mL of 7% sodium bicarbonate. We examined the frequency and severity of phlebitis among patients who received a 2-h PGE1 infusion twice daily. Eighteen patients who were hospitalized for peripheral vascular disease between June 1998 and May 1999 were studied. All of them were men and their mean age was 63.3 ±8.9 years (range: 47-78 years). Fourteen patients had arteriosclerosis obliterans and four had Buerger's disease. When the severity of phlebitis was determined according to Dinley's criteria, two patients (11%) had grade 0, four patients (22%) had grade 1, eleven patients (61%) had grade 2, and one patient (6%) had grade 3 phlebitis. Usually, PGE1 infusion therapy is stopped when phlebitis reaches grade 4 or more, but there were no such cases in this study. We also found that aging was significantly correlated with a decrease in the severity of phlebitis (Spearman's rank correlation test: r = -0.545, p = 0.0193).
Primary Pulmonary Hypertension in HIV Patients: A Systematic Review
Authors: Pellicelli Adriano M. , Barbaro Giuseppe , Palmieri Fabrizio , Girardi Enrico , D'Ambrosio Cecilia , Rianda Alessia , Barbarini Giorgio , Frigiotti Daniela , Borgia Maria Clotilde , Petrosillo Nicola 
Published: July 2008

The relationship between grade of pulmonary hypertension and factors associated with human immunodeficiency virus among patients with HIV infection is poorly documented. This report documents the most extensive attempt made thus far to determine whether a relationship exists between degree of pulmonary hypertension and the following conditions: HIV risk factor, degree of immunosuppression, presence or absence of AIDS, and presence or absence of liver cirrhosis. A retrospective study involving a search of the published literature on primary pulmonary hypertension among HIV cases from 1987 to 1998, using the Medline and Aidsline databases was conducted. Patients for whom secondary causes of pulmonary hypertension could be excluded were selected, and the following information for each was recorded: age, gender, risk factors for HIV infection, HIV disease stage according to the Centers for Disease Control, previous oppor tunistic and neoplastic diseases, CD4+ cell count (cells/L), presence or absence of liver cirrhosis, pulmonary systolic artery pressure level, and lung pathology specimens. Information about the patient's survival time was also recorded. Seventy-six patients were judged to have primary pulmonary hypertension and were included in the study. While no correlation was found between pulmonary systolic artery pressure level and CD4+ cell counts, a statistically significant difference was found between HIV-positive patients with and without AIDS as determined by the Centers for Disease Control criteria with regard to the degree of pulmonary hypertension, expressed as pulmonary systolic artery pressure level (85.4 ± 17 mm Hg vs 71.8 ± 15 mm Hg, p < 0.013). Although a higher PAPS was present in HIV cirrhotic patients, a statistically significant difference was not found between degree of pulmonary hyper tension and evidence of hepatic cirrhosis (85 ±21 mm Hg vs 73.1 ± 15 mm Hg, p < 0.062). Patients with AIDS and primary pulmonary hypertension present a higher degree of pulmonary hypertension than non-AIDS patients. Pulmonary hypertension associated with HIV seems to be related to a cytokine-related stimulation and proliferation of endothelium. High levels of cytokines present in AIDS patients can favor pulmonary hypertension, but the role of a host response to HIV—determined by one or more HLA subtypes—is suspected to enhance high cytokine production levels.
Percutaneous Balloon Pericardiotomy for Patients with Malignant Pericardial Effusion Including Three Malignant Pleural Mesotheliomas
Authors: Övünc Kenan , Aytemir Kudret , Özer Necla , Atalar Enver , Aksöyek Serdar , Nazh Nasih , Gürsel Güner , Kes Sirri 
Published: July 2008

Ten patients were enrolled in this study to evaluate the therapeutic value of percutaneous balloon pericardiotomy in patients with symptomatic pericardial effusion secondary to malignant diseases. Four patients had breast cancer; 2 had lung cancer; 1 had non-Hodgkin's lymphoma; and 3 had malignant pleural mesothelioma, which is commonly seen in Central Anatolian region of Turkey. All patients underwent percutaneous balloon pericardiotomy with monofoil balloons (Mansfield, NuMed). No complication was seen during these procedures. In 3 patients, the balloon could not be expanded completely and was entered from a more lateral position by a second puncture. There was no recurrence of pericardial effusion in 6 of 7 patients without mesothelioma. After percutaneous balloon pericardiotomy, surgical subxiphoid windowing was performed due to drainage greater than 100 mL/day in a patient with lung cancer and in 1 patient with mesothelioma. In the other 2 patients with mesothelioma, recur rence of pericardial effusion was seen and then subxiphoid surgical windowing was performed due to development of cardiac tamponade in 1 of them. All the patients died 68.6 ±36 days later due to the primary malignancies. The survival time of patients with mesothelioma was shorter than that of the others (p < 0.05). These results suggest that percutaneous balloon pericardiotomy may be used in the treatment of patients with malignant pericardial effusion as an alternative to surgical pericar dial window creation. But in patients with malignant pleural mesothelioma, the success rate of this procedure was lower than that of the others.
Association of Left Ventricular Hypertrophy and Aortic Dilation in Patients with Acute Thoracic Aortic Dissection
Authors: Iarussi Diana , Caruso Aurelio , Galderisi Maurizio , Covino Franco Enrico , Dialetto Giovanni , Bossone Eduardo , de Divitiis Oreste , Cotrufo Maurizio 
Published: July 2008

This study was designed to evaluate the impact of left ventricular mass on aortic diameters in patients who presented with acute thoracic aortic dissection where aortic dilation is common. Retrospective review of transthoracic and transesophageal echocardiograms was conducted for 63 patients treated for acute thoracic aortic dissection and for 16 normal subjects who were comparable for gender prevalence, age, heart rate, and blood pressure. The diameter of the aortic root was measured by transthoracic echocardiography. Diameters of the ascending aorta, and of the aorta at locations of 25, 30, and 35 cm from the dental arch were measured by transesophageal echocardiography. The findings indicated that all aortic diameters were significantly larger in patients with aortic dissection. Patients with aortic dissection also presented with greater left ventricular mass indices (p < 0.00001) than normal subjects. Fractional shortening and left atrial diameter measurements obtained in patients with aortic dissection were similar to those obtained in the control group. Overall, the left ventricular mass index exhibited univariate relationships with aortic root diameter (r= 0.27, p<0.02) and aortic diameters at 25 cm (r=0.51, p < 0.00001), 30 cm (r= 0.58, p < 0.00001), and 35 cm (r= 0.55, p < 0.00001) distal to the arch but not with the diameter of the ascending aorta. After adjusting for gender, body mass index, history of hyper tension and aortic dissection extent (Stanford types) by separate multivariate models, the authors found that the left ventricular mass index was independently associated with aortic diameters at 25 cm (β = 0.32, p < 0.001), 30 cm (β = 0.38, p < 0.0001), and 35 cm (β = 0.34, p < 0.0005) distal to the arch. They conclude that left ventricular mass is independently asso ciated with aortic arch and descending aorta diameters in patients with acute thoracic aortic dissection. Left ventricular hypertrophy may be considered a risk factor for aortic enlarge ment and subsequent dissection.