bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polarimetric Signatures in Supercell Thunderstorms
Authors: Kumjian Matthew R. , Ryzhkov Alexander V. 
Published: July 2008

Abstract
Data from polarimetric radars offer remarkable insight into the microphysics of convective storms. Numerous tornadic and nontornadic supercell thunderstorms have been observed by the research polarimetric Weather Surveillance Radar-1988 Doppler (WSR-88D) in Norman, Oklahoma (KOUN); additional storm data come from the Enterprise Electronics Corporation “Sidpol” C-band polarimetric radar in Enterprise, Alabama, as well as the King City C-band polarimetric radar in Ontario, Canada. A number of distinctive polarimetric signatures are repeatedly found in each of these storms. The forward-flank downdraft (FFD) is characterized by a signature of hail observed as near-zero ZDR and high ZHH. In addition, a shallow region of very high ZDR is found consistently on the southern edge of the FFD, called the ZDR “arc.” The ZDR and KDP columns and midlevel “rings” of enhanced ZDR and depressed ρHV are usually observed in the vicinity of the main rotating updraft and in the rear-flank downdraft (RFD). Tornado touchdown is associated with a well-pronounced polarimetric debris signature. Similar polarimetric features in supercell thunderstorms have been reported in other studies. The data considered here are taken from both S- and C-band radars from different geographic locations and during different seasons. The consistent presence of these features may be indicative of fundamental processes intrinsic to supercell storms. Hypotheses on the origins, as well as microphysical and dynamical interpretations of these signatures, are presented. Implications about storm morphology for operational applications are suggested.
Regional Climate Change in Tropical and Northern Africa due to Greenhouse Forcing and Land Use Changes
Authors: Paeth Heiko , Born Kai , Girmes Robin , Podzun Ralf , Jacob Daniela 
Published: July 2008

AbstractHuman activity is supposed to affect the earth’s climate mainly via two processes: the emission of greenhouse gases and aerosols and the alteration of land cover. While the former process is well established in state-of-the-art climate model simulations, less attention has been paid to the latter. However, the low latitudes appear to be particularly sensitive to land use changes, especially in tropical Africa where frequent drought episodes were observed during recent decades. Here several ensembles of long-term transient climate change experiments are presented with a regional climate model to estimate the future pathway of African climate under fairly realistic forcing conditions. Therefore, the simulations are forced with increasing greenhouse gas concentrations as well as land use changes until 2050. Three different scenarios are prescribed in order to assess the range of options inferred from global political, social, and economical development. The authors find a prominent surface heating and a weakening of the hydrological cycle over most of tropical Africa, resulting in enhanced heat stress and extended dry spells. In contrast, the large-scale atmospheric circulation in upper levels is less affected, pointing to a primarily local effect of land degradation on near-surface climate. In the model study, it turns out that land use changes are primarily responsible for the simulated climate response. In general, simulated climate changes are not concealed by internal variability. Thus, the effect of land use changes has to be accounted for when developing more realistic scenarios for future African climate.
Coupling between Sea Surface Temperature and Low-Level Winds in Mesoscale Numerical Models
Authors: Song Qingtao , Chelton Dudley B. , Esbensen Steven K. , Thum Nicolai , O’Neill Larry W. 
Published: July 2008

Abstract
This study evaluates the impacts of sea surface temperature (SST) specification and grid resolution on numerical simulations of air–sea coupling near oceanic fronts through analyses of surface winds from the European Centre for Medium-Range Weather Forecasts (ECMWF) model. The 9 May 2001 change of the boundary condition from the Reynolds SST analyses to the NOAA Real-Time Global (RTG) SST in the ECMWF model resulted in an abrupt increase in mesoscale variance of the model surface winds over the ocean. In contrast, the 21 November 2000 change of the grid resolution resulted in an abrupt increase in mesoscale variability of surface winds over mountainous regions on land but had no significant effect on winds over the ocean.
To further investigate model sensitivity to the SST boundary condition and grid resolution, a series of simulations were made with the Weather Research and Forecasting (WRF) model over a domain encompassing the Agulhas return current (ARC: also called “retroflection”) region in the south Indian Ocean. Results from three WRF simulations with SST measured by the Advanced Microwave Scanning Radiometer on the Earth Observing System Aqua satellite (AMSR-E) and the Reynolds and RTG SST analyses indicate the vital importance of the resolution of the SST boundary condition for accurate simulation of the air–sea coupling between SST and surface wind speed. WRF simulations with grid spacings of 40 and 25 km show that the latter increased energy only on scales shorter than 250 km. In contrast, improved resolution of SST significantly increased the mesoscale variability for scales up to 1000 km.
Further sensitivity studies with the WRF model conclude that the weak coupling of surface wind speeds from the ECMWF model to SST is likely attributable primarily to the weak response of vertical turbulent mixing to SST-induced stability in the parameterization of boundary layer turbulence, with an overestimation of vertical diffusion by about 60% on average in stable conditions and an underestimation by about 40% in unstable conditions.
The Influence of Lateral Advection on the Residual Estuarine Circulation: A Numerical Modeling Study of the Hudson River Estuary
Authors: Scully Malcolm E. , Geyer W. Rockwell , Lerczak James A. 
Published: July 2008

Abstract
In most estuarine systems it is assumed that the dominant along-channel momentum balance is between the integrated pressure gradient and bed stress. Scaling the amplitude of the estuarine circulation based on this balance has been shown to have predictive skill. However, a number of authors recently highlighted important nonlinear processes that contribute to the subtidal dynamics at leading order. In this study, a previously validated numerical model of the Hudson River estuary is used to examine the forces driving the residual estuarine circulation and to test the predictive skill of two linear scaling relationships. Results demonstrate that the nonlinear advective acceleration terms contribute to the subtidal along-channel momentum balance at leading order. The contribution of these nonlinear terms is driven largely by secondary lateral flows. Under a range of forcing conditions in the model runs, the advective acceleration terms nearly always act in concert with the baroclinic pressure gradient, reinforcing the residual circulation. Despite the strong contribution of the nonlinear advective terms to the subtidal dynamical balance, a linear scaling accurately predicts the strength of the observed residual circulation in the model. However, this result is largely fortuitous, as this scaling does not account for two processes that are fundamental to the estuarine circulation. The skill of this scaling results because of the compensatory relationship between the contribution of the advective acceleration terms and the suppression of turbulence due to density stratification. Both of these processes, neither of which is accounted for in the linear scaling, increase the residual estuarine circulation but have an opposite dependence on tidal amplitude and, consequently, strength of stratification.
Wintertime Supercell Thunderstorms in a Subtropical Environment: A Diagnostic Study
Authors: Wang Chung-Chieh , Chen George Tai-Jen , Yang Shan-Chien , Chou Hung-Chi 
Published: July 2008

AbstractThe present study documents the environment, initiation, and evolution of three isolated supercell storms on 19 December 2002, as the first case near Taiwan reported in the literature, mainly using radar data and manual and gridded analyses. In a subtropical environment, the supercells occurred behind a winter cold front that provided a large west-southwesterly vertical wind shear of 6.4 × 10−3 s−1 at 0–3 km. This combined with weak-to-moderate instability (CAPE = 887 J kg−1) above the shallow surface cold air to yield a favorable environment for supercells. An approaching upper-level jet (ULJ) at 200 hPa also provided strong shear through deep layers farther aloft. Prior to storm initiation, significant daytime solar heating occurred over the mountain slopes along the coast of southeastern China, leading to development of local circulation and onshore/upslope winds, resulting in convergence and uplifting. Three storms were initiated about 80 km inland around 1400 LST near the peaks of local terrain with a northeast–southwest alignment. After formation, the three storms evolved into isolated supercells and each experienced multiple splits. The right-moving storms were usually stronger than left-moving ones and traveled eastward rapidly at about 18 m s−1 across the Taiwan Strait. The storms reached their maximum strength over the strait where low-level shear intensified during the day due to cold air surge. The northern storm also registered a peak reflectivity of 72 dBZ, the strongest ever recorded by any radar in Taiwan. Eventually, the three supercell storms made landfall over Taiwan, producing swaths of rain, hail, and property damages. Before they diminished after midnight, each of the three storms had lasted for about 10 h and propagated for over 550 km.
The impact of disabilities on quality of life in people with multiple sclerosis
Authors: Wynia K , Middel B , van Dijk JP , De Keyser JHA , Reijneveld SA 
Published: July 2008

Objective People with Multiple Sclerosis (MS) experience lower levels of quality of life (QOL) than people from the general population. We examined the relative impact of MS-related disabilities on QOL. Method Data were obtained from a sample of 530 patients who completed the Multiple Sclerosis Impact Profile (MSIP), a disability measure based on the International Classification of Functioning,Disabilities and Health (ICF) and two generic health-related QOL measures, the Medical Outcome study Short Form Questionnaire (SF-36) and the World Health Organization Quality Of Life-BREF (WHOQOL-BREF). The impact of disabilities on QOL was estimated using hierarchical multiple regression analyses after controlling for the clinical course of MS. Results Disabilities contributed to a unique and substantial extent to QOL variance. “Impairments in mental functions” was the most important QOL predictor. “Fatigue” showed the highest prevalence and severity scores, while the impact on QOL was limited. The estimated impact on QOL appeared to be dependent on the applied QOL measure: the WHOQOL-BREF was sensitive to disabilities related to all four ICF components, while the SF-36 was only sensitive to disabilities belonging to the 'body functions' and ‘activities’ components. Conclusion Treatment programmes should target impairments in cognitive functioning, emotional functioning and sleep. Interventions are best evaluated using the WHOQOL-BREF.
Smoking worsens the prognosis in multiple sclerosis
Authors: Sundström P , Nyström L 
Published: July 2008

Objective To estimate the effect of smoking on the risk for progression in multiple sclerosis (MS). Methods Self-reported data were used on smoking habits in 122 incident cases with disability assessments made after a median of 6 years disease duration. Results Ever smokers were more likely to have progressive disease compared with never smokers ( P < 0.01). This was most pronounced in ever smokers with early smoking debut (≤15 years of age) for whom progressive disease was significantly more likely and occurred at an earlier age, compared with those with later smoking debut ( P < 0.01 for both) or never smokers ( P < 0.01 for both). Earlysmoking start also predisposed to a progressive disease from onset when compared with never smokers ( P = 0.012). A multivariate Cox regression analysis of sex, age at disease onset (above vs. under median) and smoking (ever vs. never) status showed that cases with late disease onset had three times higher risk and ever smokers had twice as high a risk for progression. Conclusion Past smoking is associated with a worsened prognosis in MS. The negative effect from smoking is most obvious in ever smokers with early smoking debut, which also affects MS phenotype significantly.
The impact of sexual dysfunction on the quality of life measured by MSQoL-54 in patients with multiple sclerosis
Authors: Tepavcevic DK , Kostic J , Basuroski ID , Stojsavljevic N , Pekmezovic T , Drulovic J 
Published: July 2008

Objective Sexual dysfunction (SD) is a common but often overlooked symptom in multiple sclerosis (MS). The aim of this study was to estimate the frequency, type, and intensity of SD in our patients with MS and to investigate its influence on all the domains of quality of life. Methods The study population comprised a cohort of 109 patients with MS (McDonald's criteria, 2001). SD was quantified by a Szasz sexual functioning scale. Health-related quality of life was measured by a disease-specific instrument MSQoL-54 (Serbian version). Results The presence of at least one symptom of SD was found in about 84% of the men and in 85% of the women. The main complaints in women were reduced libido, difficulties in achieving orgasm, and decreased vaginal lubrication; in men, the main complaints were reduced libido, incomplete erections, and premature ejaculation. In women, statistically significant negative correlations between the presence and level of SD and quality of life domains were reached for all subscales ( P < 0.01), except for the Pain subscale ( P = 0.112). In men, negative correlations were also observed for all domains, but they were statistically significant for physical health, physical role limitations, social function, health distress, sexual function, and sexual function satisfaction ( P < 0.01). We found that the presence of all the analyzed types of sexual problems statistically significantly lowered scores on the sexual function and the sexual function satisfaction subscales in both men and women ( P < 0.01). The most prominent impact on both domains was observed for the total loss of erection in men and for anorgasmia in women. Conclusions Our results reveal that frequent occurrence of SD in MS patients prominently affects all aspects of their quality of life.
Neuropsychological dysfunction, depression, physical disability, and coping processes in families with a parent affected by multiple sclerosis
Authors: Ehrensperger MM , Grether A , Romer G , Berres M , Monsch AU , Kappos L , Steck B 
Published: July 2008

Background Families with a parent suffering from multiple sclerosis (MS) must cope with the unpredictable course of the disease. Most studies analyzing factors that influence coping abilities in families with a member affected with MS used questionnaires to assess this ability. Methods On the contrary, the present study used a semi-structured psychiatric interview and used the resulting information to calculate a general measure of coping ability (coping index [CI]). We administered this interview to 44 MS patients, their partners and offspring and conducted a neuropsychological and physical evaluation of the patients to determine the impact of physical disability, cognitive dysfunction, and depression on the process of coping by the patient, the healthy partner, and children. Results The CI of patients was best predicted by measures of their depressive symptoms, divided attention, and estimated verbal intelligence. None of the patient variables predicted the CI of healthy partners or their offspring. We found an association between the CI of the healthy partner and the children. Conclusions These findings suggest that MS patients’ emotional and neuropsychological functions are associated with their ability to cope with the disease. These should be carefully assessed at the beginning of treatment so that those factors known to negatively influence patient coping are targeted in the treatment plan if necessary. Comprehensive care of a patient with MS should include support of coping abilities of the family members.
Smoking is a risk factor for early conversion to clinically definite multiple sclerosis
Authors: Di Pauli F , Reindl M , Ehling R , Schautzer F , Gneiss C , Lutterotti A , O’Reilly EJ , Munger KL , Deisenhammer F , Ascherio A , Berger T 
Published: July 2008

Background Cigarette smoking increases the risk for development of multiple sclerosis and modifies the clinical course of the disease. In this study, we determined whether smoking is a risk factor for early conversion to clinically definite multiple sclerosis after a clinically isolated syndrome. Methods We included 129 patients with a clinically isolated syndrome, disseminated white-matter lesions on brain magnetic resonance imaging, and positive oligoclonal bands in the cerebrospinal fluid. The patients’ smoking status was obtained at the time of the clinically isolated syndrome. Results During a follow-up time of 36 months, 75% of smokers but only 51% of non-smokers developed clinically definite multiple sclerosis, and smokers had a significantly shorter time interval to their first relapse. The hazard ratio for progression to clinically definite multiple sclerosis was 1.8 (95% confidence interval, 1.2–2.8) for smokers compared with non-smokers ( P = 0.008). Conclusions Smoking is associated with an increased risk for early conversion to clinically definite multiple sclerosis after a clinically isolated syndrome, and our results suggest that smoking is an independent but modifiable risk factor for disease progression of multiple sclerosis. Therefore, it should be considered in the counseling of patients with a clinically isolated syndrome.
From structure topology to chemical composition. VI. Titanium silicates: the
crystal structure and crystal chemistry of bornemanite, a group III Ti-disilicate
mineral
Authors: Cámara F. , Sokolova E. 
Published: July 2008

Abstract
The crystal structure of bornemanite, ideally
Na6☐BaTi2Nb(Si2O7)2(PO4)O2(OH)F,
a = 5.4587(3), b = 7.1421(5), c = 24.528(2) Å, α = 96.790(1), β = 96.927(1), γ =
90.326(1)°, V = 942.4(2) Å3, space
group (P1̄), Z = 2, Dcalc. = 3.342 g
cm–3, from the Lovozero alkaline massif, Kola Peninsula,
Russia, has been solved and refined to R1 = 6.36% on the
basis of 4414 unique reflections (Fo >4sF). Electron microprobe analysis
yielded the empirical formula
(Na6.07Mn2+0.23Ca0.06☐0.64)Σ7.00
(Ba0.73K0.13Sr0.06☐0.08)Σ1.00(Ti2.05Nb0.80Zr0.02Ta5+0.01Fe3+0.03Al0.02Mn2+0.06Mg0.01)Σ3.00(Si2O7)2(P0.97O4)O2
[F1.27(OH)0.74]Σ2.01.
The crystal structure of bornemanite is a combination of a TS (titanium silicate)
block and an I (intermediate) block. The TS block consists
of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage
and stereochemistry typical for Group III (Ti = 3 a.p.f.u.) of Ti-disilicate
minerals: two H sheets connect to the O sheet such that two
(Si2O7) groups link to the trans
edges of a Ti octahedron of the O sheet. The O sheet cations give
Na3Ti (4 a.p.f.u.). The TS block has two different H
sheets, H1 and H2, where
(Si2O7) groups link to
[5]Ti and [6]Nb polyhedra, and there
are two peripheral sites which are occupied by Ba and Na, respectively. There are
two I blocks: the
I1 block is a layer of Ba atoms;
the I2 block consists of Na polyhedra
and (PO4) tetrahedra.
Incorporation of REE into leucophanite: a compositional and structural
study
Authors: Friis H. , Balić-Žunić T. , Williams C. T. , R. Garcia-Sanchez  
Published: July 2008

Abstract
The crystal structures of nine, and the chemical compositions of ten, natural
samples of leucophanite, ideally
NaCaBeSi2O6F, were investigated. The
analysed samples display a large compositional variation with trace-element
abundances >50,000 ppm, primarily due to rare earth elements
(REE). Fromthese data, we propose a substitution
scheme for the incorporation of REE for Ca, with
additional Na substituting for Ca and the generation of vacancies to ensure charge
balance. Compositional zonation was observed in some samples; this zonation
correlates with variations in cathodoluminescence. The crystal structure of the
nine analysed samples could all be refined in space group
P212121. We
found no evidence for a reduction of symmetry with increased trace-element
concentration. Various twin combinations were observed and these seem related to
crystallization conditions rather than structural or chemical factors.
Host immune gene polymorphisms in combination with clinical and demographic factors predict late survival in diffuse large B-cell lymphoma patients in the pre-rituximab era
Authors: Habermann Thomas M. , Wang Sophia S. , Maurer Matthew J. , Morton Lindsay M. , Lynch Charles F. , Ansell Stephen M. , Hartge Patricia , Severson Richard K. , Rothman Nathaniel , Davis Scott , Geyer Susan M. , Cozen Wendy , Chanock Stephen J. , Cerhan James R. 
Published: July 2008

AbstractTo evaluate the hypothesis that host germ line variation in immune genes is associated with overall survival in diffuse large B-cell lymphoma (DLBCL), we genotyped 73 single nucleotide polymorphisms (SNPs) from 44 candidate genes in 365 DLBCL patients diagnosed from 1998 to 2000. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of SNPs with survival after adjusting for clinical factors. During follow-up, 96 (26%) patients died, and the median follow-up was 57 months for surviving patients. The observed survival of this cohort was consistent with population-based estimates conditioned on surviving 12 months. An IL10 haplotype (global P = .03) and SNPs in IL8RB (rs1126580; HRAG/GG = 2.11; CI, 1.28-3.50), IL1A (rs1800587; HRCT/TT = 1.90; CI, 1.26-2.87), TNF (rs1800629; HRAG/GG = 1.44; CI, 0.95-2.18), and IL4R (rs2107356; HRCC/CT = 1.97; CI, 1.01-3.83) were the strongest predictors of overall survival. A risk score that combined the latter 4 SNPs with clinical factors was strongly associated with survival in a Cox model (P = 6.0 × 10−11). Kaplan-Meier 5-year survival estimates for low, intermediate-low, intermediate-high, and high-risk patients were 94%, 79%, 60%, and 48%, respectively. These data support a role for germ line variation in immune genes, particularly genes associated with a proinflammatory state, as predictors of late survival in DLBCL.