bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the Impact of Simulated COSMIC GPS Radio Occultation Data on Weather Analysis over the Antarctic: A Case Study
Authors: Cucurull L. , Kuo Y-H. , Barker D. , Rizvi S. R. H. 
Published: November 2006

Abstract
The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission was launched in April 2006. As part of its mission, COSMIC will provide approximately 2500–3000 global positioning system (GPS) radio occultation (RO) soundings per day distributed uniformly around the globe. In this study, a series of sensitivity experiments are conducted to assess the potential impact of COSMIC GPS RO data on the regional weather analysis over the Antarctic. Soundings of refractivity are assimilated into the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model using its three-dimensional variational data assimilation system. First, the sensitivity of the analysis to the background error statistics and balance constraints is analyzed. Then the effects of the data distribution and the observational error of the simulated refractivity observations are examined. In this study, the simulated soundings are based on a realistic set of orbit parameters of the COSMIC constellation. Analysis of the assimilation results indicates the significant potential impact of COSMIC data on regional analyses over the Antarctic. In the one case studied here, the root-mean-square differences between the background and observed values are reduced by 12% in the horizontal wind component, 17% in the temperature variable, 8% in the specific humidity, and 22% in the pressure field when COSMIC GPS RO data are assimilated into the system by using a 6-h assimilation time window. These preliminary results suggest that COSMIC GPS RO data can have a significant impact on operational numerical weather analysis in the Antarctic.
A Singular Vector Perspective of 4DVAR: The Spatial Structure and Evolution of Baroclinic Weather Systems
Authors: Johnson Christine , Hoskins Brian J. , Nichols Nancy K. , Ballard Susan P. 
Published: November 2006

Abstract
The extent to which the four-dimensional variational data assimilation (4DVAR) is able to use information about the time evolution of the atmosphere to infer the vertical spatial structure of baroclinic weather systems is investigated. The singular value decomposition (SVD) of the 4DVAR observability matrix is introduced as a novel technique to examine the spatial structure of analysis increments. Specific results are illustrated using 4DVAR analyses and SVD within an idealized 2D Eady model setting. Three different aspects are investigated. The first aspect considers correcting errors that result in normal-mode growth or decay. The results show that 4DVAR performs well at correcting growing errors but not decaying errors. Although it is possible for 4DVAR to correct decaying errors, the assimilation of observations can be detrimental to a forecast because 4DVAR is likely to add growing errors instead of correcting decaying errors. The second aspect shows that the singular values of the observability matrix are a useful tool to identify the optimal spatial and temporal locations for the observations. The results show that the ability to extract the time-evolution information can be maximized by placing the observations far apart in time. The third aspect considers correcting errors that result in nonmodal rapid growth. 4DVAR is able to use the model dynamics to infer some of the vertical structure. However, the specification of the case-dependent background error variances plays a crucial role.
Effects of Vertical Wind Shear and Storm Motion on Tropical Cyclone Rainfall Asymmetries Deduced from TRMM
Authors: Chen Shuyi S. , Knaff John A. , Marks Frank D. 
Published: November 2006

Abstract
Vertical wind shear and storm motion are two of the most important factors contributing to rainfall asymmetries in tropical cyclones (TCs). Global TC rainfall structure, in terms of azimuthal distribution and asymmetries relative to storm motion, has been previously described using the Tropical Rainfall Measuring Mission Microwave Imager rainfall estimates. The mean TC rainfall distribution and the wavenumber-1 asymmetry vary with storm intensity and geographical location among the six oceanic basins. This study uses a similar approach to investigate the relationship between the structure of TC rainfall and the environmental flow by computing the rainfall asymmetry relative to the vertical wind shear. The environmental vertical wind shear is defined as the difference between the mean wind vectors of the 200- and 850-hPa levels over an outer region extending from the radius of 200–800 km around the storm center. The wavenumber-1 maximum rainfall asymmetry is downshear left (right) in the Northern (Southern) Hemisphere. The rainfall asymmetry decreases (increases) with storm intensity (shear strength). The rainfall asymmetry maximum is predominantly downshear left for shear values &gt; 7.5 m s−1. Large asymmetries are usually observed away from the TC centers. As TC intensity increases, the asymmetry maximum shifts upwind to the left. The analysis is further extended to examine the storm motion and the vertical wind shear and their collective effects on TC rainfall asymmetries. It is found that the vertical wind shear is a dominant factor for the rainfall asymmetry when shear is &gt;5 m s−1. The storm motion–relative rainfall asymmetry in the outer rainband region is comparable to that of shear relative when the shear is &lt;5 m s−1, suggesting that TC translation speed becomes an important factor in the low shear environment. The overall TC rainfall asymmetry depends on the juxtaposition and relative magnitude of the storm motion and environmental shear vectors in all oceanic basins.
Will Perturbing Soil Moisture Improve Warm-Season Ensemble Forecasts? A Proof of Concept
Authors: Sutton Christian , Hamill Thomas M. , Warner Thomas T. 
Published: November 2006

Abstract
Current generation short-range ensemble forecast members tend to be unduly similar to each other, especially for components such as surface temperature and precipitation. One possible cause of this is a lack of perturbations to the land surface state. In this experiment, a two-member ensemble of the Advanced Research Weather Research and Forecasting (WRF) model (ARW) was run from two different soil moisture analyses. One-day forecasts were conducted for six warm-season cases over the central United States with moderate soil moistures, both with explicit convection at 5-km grid spacing and with parameterized convection at 20-km grid spacing. Since changing the convective parameterization has previously been demonstrated to cause significant differences between ensemble forecast members, 20-km simulations were also conducted that were initialized with the same soil moisture but that used two different convective parameterizations as a reference. At 5 km, the forecast differences due to changing the soil moisture were comparable to the differences in 20-km simulations with the same soil moisture but with a different convective parameterization. The differences of 20-km simulations from different soil moistures were occasionally large but typically smaller than the differences from changing the convective parameterization. Thus, perturbing the state of the land surface for this version of WRF/ARW was judged to be likely to increase the spread of warm-season operational short-range ensemble forecasts of precipitation and surface temperature when soil moistures are moderate in value, especially if the ensemble is comprised of high-resolution members with explicit convection.
Computation of the Streamfunction and Velocity Potential for Limited and Irregular Domains
Authors: Li Zhijin , Chao Yi , McWilliams James C. 
Published: November 2006

Abstract
An algorithm is proposed for the computation of streamfunction and velocity potential from given horizontal velocity vectors based on solving a minimization problem. To guarantee the uniqueness of the solution and computational reliability of the algorithm, a Tikhonov regularization is applied. The solution implies that the obtained streamfunction and velocity potential have minimal magnitude, while the given velocity vectors can be accurately reconstructed from the computed streamfunction and velocity potential. Because the formulation of the minimization problem allows for circumventing the explicit specification of separate boundary conditions on the streamfunction and velocity potential, the algorithm is easily applicable to irregular domains. By using an advanced minimization algorithm with the use of adjoint techniques, the method is computationally efficient and suitable for problems with large dimensions. An example is presented for coastal oceans to illustrate the practical application of the algorithm.
Formation and Maintenance Mechanisms of the Stable Layer over the Po Valley during MAP IOP-8
Authors: Hoggarth Allison M. , Reeves Heather Dawn , Lin Yuh-Lang 
Published: November 2006

Abstract
During intensive observation period 8 (IOP-8) of the Mesoscale Alpine Program, a strong stable layer formed over Italy’s Po Valley and the northern Ligurian Sea. This stable layer has been shown in previous research to be important for the formation of convection over the Ligurian Sea and the lack thereof over the Po Valley and southern slopes of the Alps. The purpose of this study is to investigate the mechanisms that acted to form and maintain the stable layer during IOP-8. This aim is accomplished through inspection of observed data as well as numerical simulations and sensitivity experiments. Observations and reanalysis data show that starting on 17 October 1999, a relatively cool, stable air mass was advected around the eastern side of the Alps into the lower atmosphere of the Po Valley. Both observational data and model output show this air mass as being blocked as it encountered the western Alps, thus resulting in an accumulation of cool, stable air at low levels in the Po Valley during the ensuing 60 h. When southerly flow approached northern Italy beginning on 20 October 1999, both the western Alps and the northern Alps appeared to help retain the low-level, cool, stable air over the Po Valley. A trajectory and sounding analysis shows that warmer, less stable air originating from over the southern Mediterranean Sea was advected atop the low-lying stable layer within the Po Valley. It is hypothesized that this differential advection, as well as blocking by the western and northern flanks of the Alps, were responsible for the longevity of the stable layer. A series of numerical simulations and sensitivity experiments were performed to test the above hypotheses. These tests support the hypotheses. Other mechanisms were also considered, including blocking of solar radiation by clouds, friction, and evaporative cooling. These simulations revealed that all three processes were critical for the longevity of the stable layer and point to the importance of accurate model representation of subgrid-scale processes.
Analysis of Hurricane Catarina (2004)
Authors: McTaggart-Cowan Ron , Bosart Lance F. , Davis Christopher A. , Atallah Eyad H. , Gyakum John R. , Emanuel Kerry A. 
Published: November 2006

Abstract
The development of Hurricane Catarina over the western South Atlantic Ocean in March 2004 marks the first time that the existence of a hurricane has been confirmed by analysis and satellite imagery in the South Atlantic basin. The storm undergoes a complex life cycle, beginning as an extratropical precursor that moves east-southeastward off the Brazilian coast and toward the midlatitudes. Its eastward progress is halted and the system is steered back westward toward the Brazilian coast as it encounters a strengthening dipole-blocking structure east of the South American continent. Entering the large region of weak vertical shear that characterizes this blocking pattern, Catarina begins a tropical transition process over anomalously cool 25°C ocean waters above which an elevated potential intensity is supported by the cold upper-level air associated with the trough component of the block. As the convective outflow from the developing tropical system reinforces the ridge component of the dipole block, the storm is accelerated westward toward the Santa Catarina province of Brazil and makes landfall there as a nominal category-1 hurricane, causing extensive damage with its heavy rains and strong winds.
The complex evolution of the system is analyzed using a suite of diagnostic tools, and a conceptual model of the tropical transition and steering processes in the presence of a dipole block is developed. Once the essential properties of the upper-level flow are established, an analog study is undertaken to investigate lower-atmospheric responses to similar blocking regimes. Persistent dipole-blocking structures are found to be rare east of South America; however, the evolution of systems occurring during these periods is shown to be complex and to exhibit various subtropical development modes.
Ultrasound of the Paediatric Scrotum: A Pictorial Review
Authors: Kurian Raghey , de Bruyn Rose 
Published: November 2006

Scrotal pathologies in young boys have a wide differential diagnosis. Clinical presentation can vary widely and eliciting a 'patient history' can be challenging. Moreover, due to the small size of the testis and epididymis, clinical examination in most cases is difficult. Therefore, imaging of the scrotum plays a major role in the management of these disorders. Of all the imaging modalities used for evaluating scrotal disorders in children, sonography is the first and foremost. It provides excellent information regarding anatomy and blood flow, is readily accessible and can be performed relatively rapidly. Use of sedatives and intravenous access are unnecessary. A wide variety of scrotal pathologies in children are presented in this pictorial review. For ease of evaluation, we have classified the paediatric scrotal disorders based on their clinical presentations as acute painful scrotum and scrotal masses.
The effect of deoxygenation on whole-cell conductance of red blood cells from healthy individuals and patients with sickle cell disease
Authors: Browning Joseph A. , Staines Henry M. , Robinson Hannah C. , Powell Trevor , Ellory J. Clive , Gibson John S. 
Published: November 2006

Abstract
Red blood cells from patients with sickle cell disease (SCD) exhibit increased electrogenic cation permeability, particularly following deoxygenation and hemoglobin (Hb) polymerisation. This cation permeability, termed Psickle, contributes to cellular dehydration and sickling, and its inhibition remains a major goal for SCD treatment. Nevertheless, its characteristics remain poorly defined, its molecular identity is unknown, and effective inhibitors have not been established. Here, patch-clamp methodology was used to record whole-cell currents in single red blood cells from healthy individuals and patients with SCD. Oxygenated normal red blood cells had a low membrane conductance, unaffected by deoxygenation. Oxygenated HbS cells had significantly increased conductance and, on deoxygenation, showed a further rise in membrane conductance. The deoxygenation-induced pathway was variable in magnitude. It had equal permeability to Na+ and K+, but was less permeable to NMDG+ and Cl−. Conductance to Ca2+ was also of a similar magnitude to that of monovalent cations. It was inhibited by DIDS (100 μM), Zn2+ (100 μM), and by Gd3+ (IC50 of approximately 2 μM). It therefore shares some properties with Psickle. These findings represent the first electrical recordings of single HbS cells and will facilitate progress in understanding altered red blood cell cation transport characteristics of SCD.
HGF inhibits BMP-induced osteoblastogenesis: possible implications for the bone disease of multiple myeloma
Authors: Standal Therese , Abildgaard Niels , Fagerli Unn-Merete , Stordal Berit , Hjertner Øyvind , Borset Magne , Sundan Anders 
Published: December 2006

AbstractThe bone disease in multiple myeloma is caused by an uncoupling of bone formation from bone resorption. A key difference between patients with and patients without osteolytic lesion is that the latter have fewer and less active osteoblasts. Hepatocyte growth factor (HGF) is often produced by myeloma cells and is found at high concentrations in the bone marrow of patients with multiple myeloma. Here we show that HGF inhibited bone morphogenetic protein (BMP)–induced in vitro osteoblastogenesis. Thus, HGF inhibited BMP-induced expression of alkaline phosphatase in human mesenchymal stem cells (hMSCs) and the murine myoid cell line C2C12, as well as mineralization by hMSCs. Furthermore, the expression of the osteoblast-specific transcription factors Runx2 and Osterix was reduced by HGF treatment. HGF promoted proliferation of hMSCs, and the BMP-induced halt in proliferation was overridden by HGF, keeping the cells in a proliferative, undifferentiating state. BMP-induced nuclear translocation of receptor-activated Smads was inhibited by HGF, providing a possible explanation of how HGF inhibits BMP signaling. The in vitro data were supported by the observation of a negative correlation between HGF and a marker of osteoblast activity, bone-specific alkaline phosphatase (rho = −0.45, P = .008), in sera from 34 patients with myeloma. These observations suggest that HGF inhibits bone formation in multiple myeloma.
CD10−MUM1+ follicular lymphoma lacks BCL2 gene translocation and shows characteristic biologic and clinical features
Authors: Karube Kennosuke , Guo Ying , Suzumiya Junji , Sugita Yasuo , Nomura Yuko , Yamamoto Kohei , Shimizu Kei , Yoshida Shirou , Komatani Hideki , Takeshita Morishige , Kikuchi Masahiro , Nakamura Naoya , Takasu Osamu , Arakawa Fumiko , Tagawa Hiroyuki , Seto Masao , Ohshima Koichi 
Published: December 2006

AbstractCD10 and MUM1 are representative B cell differentiation markers. Follicular lymphoma (FL) is usually positive for CD10 and negative for MUM1. In this study, however, we compared 22 FLs with peculiar phenotype CD10−MUM1+ with 119 typical CD10+MUM1− FLs. All CD10−MUM1+ FL patients exhibited follicular structure with follicular dendritic meshwork, and a high rate of somatic hypermutation and ongoing mutation, similar to typical FL. However, CD10−MUM1+ FLs were encountered frequently in the elderly compared with CD10+MUM1− typical FLs (67.0 versus 58.7 years, P < .01), showed high grade (grade 3A or 3B) morphology (91% versus 17%, P < .001), diffuse proliferation (59% vs 19%, P < .001), and lacked BCL2/IGH translocation (5% versus 92.5%, P < .001), which is the most characteristic aberration in FL, and 88% showed BCL6 gene abnormalities (translocation or amplification). Our results indicate that CD10−MUM1+ FL is different from typical FL with respect to biologic and clinical features.
Transbronchial and transoesophageal (ultrasound-guided) needle aspirations for the analysis of mediastinal lesions
Authors: Herth F. J. F. , Rabe K. F. , Gasparini S. , Annema J. T. 
Published: November 2006

A tissue diagnosis of mediastinal nodes is frequently needed for accurate lung cancer staging as well as the assessment of mediastinal masses. Transbronchial needle aspiration (TBNA) is a safe procedure that is performed during routine bronchoscopy. Provided mediastinal metastases are confirmed, TBNA has a high impact on patient management. Unfortunately, TBNA remains underused in current daily practice, mainly due to the lack of real-time needle visualisation. The introduction of echo-endoscopes has overcome this problem.Endobronchial ultrasound-guided TBNA (EBUS-TBNA) allows real-time controlled tissue sampling of paratracheal, subcarinal and hilar lymph nodes. Mediastinal lymph nodes located adjacent to the oesophagus can be assessed by transoesophageal ultrasound-guided fine needle aspiration (EUS-FNA). Owing to the complementary reach of EBUS-TBNA and EUS-FNA in assessing different regions of the mediastinum, recent studies suggest that complete and accurate mediastinal staging can be achieved by the combination of both procedures.It is expected that implementation of minimally invasive endoscopic methods of endobronchial ultrasound-guided transbronchial needle aspiration and transoesophageal ultrasound-guided fine needle aspiration will reduce the need for surgical staging of lung cancer significantly.
Severe airflow obstruction and eosinophilic lung disease after Stevens–Johnson syndrome
Authors: Shah A. P. , Xu H. , Sime P. J. , Trawick D. R. 
Published: November 2006

Respiratory involvement is a frequent complication of Stevens–Johnson syndrome (SJS). However, there are very few convincing reports of persistent pulmonary sequelae, as demonstrated by spirometry, radiology and pathology.The current study presents a case of a 13-yr-old female with T-cell acute lymphocytic leukaemia who developed persistent, severe, obstructive lung disease following an episode of SJS.A lung biopsy demonstrated bronchiolar submucosal fibrosis consistent with constrictive bronchiolitis, as well as eosinophilic micro-abscesses, which, to the current authors’ knowledge, has not been previously described.The present study illustrates specific histopathological features that highlight a possible association between Stevens–Johnson syndrome, constrictive bronchiolitis and eosinophilic micro-abscesses. The eosinophils may be associated with permanent mucosal damage, as seen in the present case, by releasing mediators that have a pro-fibrogenetic role. However, further investigation is warranted.
Genotype-corrected reference values for serum angiotensin-converting enzyme
Authors: Biller H. , Zissel G. , Ruprecht B. , Nauck M. , Busse Grawitz A. , Müller-Quernheim J. 
Published: November 2006

The deletion (D)/insertion (I) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene has the greatest impact on serum ACE level in Caucasians of any factor yet discovered. The aim of the present study was to establish new ACE genotype-corrected normal ranges for serum ACE level in a population of central European origin.After a medical examination, 159 healthy Caucasians volunteered to donate blood for the study. ACE genotypes were assessed by PCR and serum ACE levels were determined using two different kinetic tests.The distribution of the D/I polymorphism of the ACE gene was in accordance with the Hardy–Weinberg equilibrium. Serum ACE levels and ACE genotypes correlated significantly, with the highest serum ACE levels in subjects with ACE genotype D/D, and the lowest serum ACE levels in subjects with genotype I/I (mean±sd,assay 1: D/D 59.3±15.1 U·L-1, D/I 45.5±15.2 U·L-1, I/I 34.8±13.7 U·L-1; assay 2: D/D 43.7±14.1 U·L-1, D/I 33.7±12.1 U·L-1, I/I 25.4±9.5 U·L-1). Although they gave different absolute values of serum ACE levels, the results of the two test kits correlated significantly.In conclusion, the present authors recommend the use of new, genotype-specific reference values for serum angiotensin-converting enzyme levels, especially to improve the sensitivity and specificity of tests for angiotensin-converting enzyme in the follow-up of sarcoidosis.