bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Taiwan Central Weather Bureau Regional Spectral Model for Seasonal Prediction: Multiparallel Implementation and Preliminary Results
Authors: Henry Juang Hann-Ming , Shiao Chih-Hui , Cheng Ming-Dean 
Published: July 2003

Abstract
A regional spectral model (RSM) is developed at the Taiwan Central Weather Bureau (CWB). It is based on the same model structure, dynamics, and physics of the CWB global spectral model (GSM) and the perturbation concept of the National Centers for Environmental Prediction (NCEP) RSM for lateral boundary treatment. The advantages of this new regional model include minimization of possible inconsistency between GSM and RSM through lateral boundary influence and reduction of resources used to manage and maintain the model.
One-dimensional decomposition is utilized to slice the model into subdomains to run on a massive parallel-processor machine. The Message-Passing Interface (MPI) is adopted to communicate among each subdomain. The computational dependency, such as the summation in spectral transformation, is a restriction for the decomposition, so that the reproducibility using different numbers of processors is achieved. The performance in terms of wall-clock time follows the theoretical curve of parallelization. It can reach 95% parallelization by “homemade” PC Linux cluster, and 90% by CWB Fujitsu VPP5000.
One case is selected to perform 2-month integration in a simulation mode and a forecast mode. The results indicate a reasonable monsoon frontal evolution as compared with analysis, and it has similar or less root-mean-square error (rmse) as compared to that of CWB GSM. The same run with NCEP RSM nested into CWB GSM shows a larger rmse than CWB RSM; it demonstrates the advantage of having the same model structure, dynamics, and physics between CWB GSM and CWB RSM.
A Three-Dimensional, Adaptive, Godunov-Type Model for Global Atmospheric Flows
Authors: Hubbard M. E. , Nikiforakis N. 
Published: July 2003

Abstract
In this paper a Godunov-type methodology is applied to three-dimensional global atmospheric modeling. Numerical issues are addressed regarding the formulation of the tracer advection problem, the application of dimensional splitting, and the implementation of a Godunov-type scheme, based on the WAF approach, on spherical geometries. Particular attention is paid to addressing the problems that arise because of the convergence of the grid lines toward the Poles. A three-dimensional model is then built on the sphere that is based on a uniform longitude–latitude–height grid. This provides the framework within which an adaptive mesh refinement (AMR) algorithm is applied, to enhance the efficiency and accuracy with which results are obtained. These methods are not commonly used in the area of atmospheric modeling, but AMR in particular is commonly used with great success in other areas of computational fluid dynamics. The model is initially validated using a series of idealized case studies that have exact solutions, but is then developed into an offline model of tracer advection, forced by data from meteorological analyses, suitable to study the evolution of trace chemical species in the atmosphere.
Use and Impact of Automated Aircraft Data in a Global 4DVAR Data Assimilation System
Authors: Cardinali Carla , Isaksen Lars , Andersson Erik 
Published: July 2003

Abstract
The use of automated aircraft data [Aircraft Meteorological Data Relay (AMDAR) and Aircraft Communication Addressing and Reporting System (ACARS)] has recently been extended in ECMWF's operational 4DVAR data assimilation system. Herein, a modified data selection procedure is reported on that allows the use of more aircraft profiling data during the aircraft's ascending and descending phase, and more of the most frequent reports at cruise level. It is shown that the accuracy of analyzed jet streams is improved through these changes, as verified against independent (non–real time) aircraft data that had not been used in the experiments. The modifications are shown to have a clear positive impact on the short- and medium-range forecast performance. The revised aircraft usage was implemented operationally in January 2002.
The impact in 4DVAR of profiles from American and European automated aircraft in ascending and descending phase has been tested in a data denial impact study, for January and July 2001. This particular impact study was run partly on the request of the WMO/Commission for Basic Systems (CBS) Expert Team on data requirements and the redesign of the global observing system. Their interest is in testing whether a modern data assimilation system (such as 4DVAR) obtains substantial benefit from the aircraft profiles, which sample very irregularly in space and time, given that America and Europe are relatively well covered by radiosondes and wind profilers. The results show a substantial positive impact of the profiling aircraft data on analysis and forecast accuracy. The short-range forecast performance is improved over North America, the North Atlantic, and Europe. In the medium range a clear positive impact is found in the North Atlantic, the European, and Arctic areas in the winter period, and beyond day 6 in the summer period. These results are statistically significant and support the ongoing WMO initiative for further expansion of the AMDAR/ACARS coverage. The results also illustrate the effectiveness of 4DVAR with respect to observations that are irregularly distributed in space and time.
Local and Regional Discriminators of Mesoscale Convective Vortex Development in Arizona
Authors: Brommer David M. , Balling Robert C. , Cerveny Randall S. 
Published: July 2003

Abstract
In approximately half of Arizona's summer season (June–September) mesoscale convective systems evolve into mesoscale convective vortices (MCVs). Analysis of satellite imagery identified MCVs in Arizona over the period 1991–2000, and local and regional rawinsonde data discriminated conditions conducive for MCV development. These results indicate that MCVs are more likely to form from convective systems when the local and regional environments are characterized by relative stability in the 850–700-hPa layer and moderate wind shear in the 500–200-hPa layer. These characteristics are similar to results reported for MCV development in the central United States.
Real-Time Multimodel Superensemble Forecasts of Atlantic Tropical Systems of 1999
Authors: Eric Williford C. , Krishnamurti T. N. , Torres Ricardo Correa , Cocke Steven , Christidis Zaphiris , Vijaya Kumar T. S. 
Published: July 2003

Abstract
In this paper, Atlantic hurricane forecasts for the year 1999 are addressed. The methodology for these forecasts is called the multimodel superensemble. This statistical method makes use of the real-time forecasts provided by a number of operational and research models to construct the superensemble forecasts. This method divides the forecast time line into two phases: a training phase and a forecast combining phase. The training phase includes an inventory of past applicable hurricane forecasts, each by the multimodels. The model biases of position and intensity errors of past forecasts are summarized via a simple linear multiple regression of these forecasts against the best-observed estimates of position and intensity. These statistics are next passed on to future forecasts of the multimodels in order to forecast the hurricanes of 1999. This method was first tested for the hurricanes of 1998 with considerable success, with some of those results summarized here. Those statistics were refined for the 1999 Atlantic hurricane season. Overall, the main result of the seasonal summary is that the position and intensity errors for the multimodel superensemble are generally less than those of all of the participating models during 1–5-day real-time forecasts. Some of the major storms of the 1999 season, such as Dennis, Floyd, Irene, and Lenny, were extremely well handled by this superensemble approach. The message of this study is that the proposed approach may be a viable way to construct improved real-time forecasts of hurricane positions and intensity.
A Numerical Study of Early Summer Regional Climate and Weather over LSA-East. Part I: Model Implementation and Verification
Authors: Zhang Da-Lin , Zheng Wei-Zhong , Xue Yong-Kang 
Published: July 2003

Abstract
The Pennsylvania State University–NCAR Mesoscale Model (MM5) and a simplified simple biosphere (SSiB) scheme are modified and then coupled to study various regional climate and weather problems. These modifications include correcting the moisture and cloud hydrometeor fields to ensure the mass conservation; incorporating the effects of dissipative heating to ensure total energy conservation; decoupling soil and vegetation types in specifying various surface parameters; and eliminating the shortwave radiation reaching the surface at points where deep convection occurs.
A 30-day integration of June 1998 over the Midwest states was used to examine the model's capability in capturing the observed wet regional climate and the passage of several mesoscale weather events. It is found that the coupled model reproduces the distribution and magnitude of monthly accumulated precipitation, the time series of area-integrated precipitation, surface pressures, and diurnal changes in surface temperatures, low-level winds and precipitation, as well as the evolution of precipitation systems across the central United States. In particular, the model reproduces well many daily weather events, including the distribution and intensity of low-level temperature and pressure perturbations and precipitation, even up to a month. The results suggest that the daily temperature, clouds, and precipitation events from the weekly to monthly scales, as well as their associated regional climate phenomena, could be reasonably simulated if the surface, boundary layer, radiation, and convective processes are realistically parameterized, and the large-scale forcing could be reasonably provided by general circulation models.
The Influence of the Downstream State on Extratropical Transition: Hurricane Earl (1998) Case Study
Authors: McTaggart-Cowan R. , Gyakum J. R. , Yau M. K. 
Published: July 2003

Abstract
The multitude of tropical–extratropical interactions that occur during an extratropical transition (ET) complicate the prediction and diagnosis of these extreme events. This study focuses on the analysis of a double ET and reintensification event that took place between 5 and 7 September 1998. Ex-Hurricanes Earl and Danielle reintensified rapidly over the western and eastern North Atlantic, respectively. A set of simulations designed to test the sensitivity of Earl's ET to features in the downstream state was run using a set of idealizations for a numerical model's initial and boundary conditions downstream of ex-Hurricane Earl. Dynamic tropopause analyses and the “PV thinking” paradigm applied under the Eady model highlight important developmental and structural differences between the tests.
In fact, two distinct solution modes are diagnosed both in the control and in the sensitivity tests. Earl's ET proceeds according to a “baroclinic mode” of redevelopment, whereas Danielle displays distinct “tropical mode” ET signatures throughout the period of investigation. The presence of a strong zonal jet immediately downstream of the transitioning cyclone is found to be sufficient to induce a baroclinic mode of redevelopment characterized by cyclonic potential vorticity rollup and strong near-surface frontogenesis. Under the influence of an upstream jet in isolation, the reintensification takes on distinctly tropical characteristics as the enhanced northward intrusion of warm, moist air ahead of the system creates a local environment favorable for a tropical mode of redevelopment. A description of the dynamics associated with these two distinct redevelopment modes may aid in the understanding and prediction of these events.
Inhibition of acute lymphoblastic and myeloid leukemias by a novel kinase inhibitor
Authors: Grunberger Thomas , Demin Peter , Rounova Olga , Sharfe Nigel , Cimpean Lorand , Dadi Harjit , Freywald Andrew , Estrov Zeev , Roifman Chaim M. 
Published: July 2003

Abstract
In recent years, synthetic tyrosine kinase inhibitors have made a rapid transition from basic research to therapeutic application. These compounds represent a major clinical advance in the approach to cancer in their relative specificity of action and decreased toxicity. We report here the effects of a novel tyrosine kinase inhibitor CR4 that interferes with growth-promoting pathways to markedly inhibit the growth and survival of both Philadelphia-positive and -negative acute lymphoblastic leukemia (ALL) as well as acute myeloid leukemia (AML). While efficiently ablating leukemic cell growth, normal cell growth and differentiation remain unaffected by CR4. CR4 demonstrates an ability to inhibit the function of multiple growth-critical kinases and yet exhibits a low level of cytotoxicity. These findings suggest that CR4 may prove to be highly effective as a therapeutic agent. (Blood. 2003;102:4153-4158)
Dose finding with retroviral vectors: correlation of retroviral vector copy numbers in single cells with gene transfer efficiency in a cell population
Authors: Kustikova Olga S. , Wahlers Anke , Kühlcke Klaus , Stähle Birgit , Zander Axel R. , Baum Christopher , Fehse Boris 
Published: July 2003

Abstract
Retroviral vectors are commonly used in clinical gene therapy, but recent observations of insertional oncogene activation in preclinical and clinical settings have forced a discussion of their safety. Here we investigated the relationship between retroviral transduction efficiency in mass cultures and the actual number of integrated vector copies in single cells using K562 leukemia and primary CD34+ cells. We found an exponential increase of integration numbers correlated to gene transfer rates and a linear increase of expression levels with insertion frequency. On average we detected one vector insertion per transduced cell for a gene transfer of less than 30%, 3 for 60%, and approximately 9 for 90% (in K562). Clonal analysis revealed strikingly increased variations of both transgene copy numbers (more than 20-fold in primary cells) and expression levels associated with higher transduction. Therefore, limiting retroviral gene transfer to approximately 30% may be suggested to avoid generating clones containing multiple insertions.
A role for Syk-kinase in the control of the binding cycle of the β2 integrins (CD11/CD18) in human polymorphonuclear neutrophils
Authors: Willeke Thomas , Schymeinsky Jürgen , Prange Peggy , Zahler Stefan , Walzog Barbara 
Published: July 2003

Abstract
A fine control of β2 integrin (CD11/CD18)-mediated firm adhesion of human neutrophils to the endothelial cell monolayer is required to allow ordered emigration. To elucidate the molecular mechanisms that control this process, intracellular protein tyrosine signaling subsequent to β2 integrin-mediated ligand binding was studied by immunoprecipitation and Western blotting techniques. The 72-kDa Syk-kinase, which was tyrosine-phosphorylated upon adhesion, was found to coprecipitate with CD18, the β-subunit of the β2 integrins. Moreover, inhibition of Syk-kinase by piceatannol enhanced adhesion and spreading but diminished N-formyl-Met-Leu-Phe-induced chemotactic migration. The enhancement of adhesiveness was associated with integrin clustering, which results in increased integrin avidity. In contrast, piceatannol had no effect on the surface expression or on the affinity of β2 integrins. Altogether, this suggests that Syk-kinase controls alternation of β2 integrin-mediated ligand binding with integrin detachment.
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and TNF-α promote the NF-κB-dependent maturation of normal and leukemic myeloid cells
Authors: Secchiero Paola , Milani Daniela , Gonelli Arianna , Melloni Elisabetta , Campioni Diana , Gibellini Davide , Capitani Silvano , Zauli Giorgio 
Published: July 2003

Abstract
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and TNF-α induced monocytic maturation of primary normal CD34-derived myeloid precursors and of the M2/M3-type acute myeloid leukemia HL-60 cell line, associated to increased nuclear factor (NF)-κB activity and nuclear translocation of p75, p65, and p50 NF-κB family members. Consistently, both cytokines also induced the degradation of the NF-κB inhibitors, IκBα and IκBɛ, and up-regulated the surface expression of TRAIL-R3, a known NF-κB target. However, NF-κB activation and IκB degradation occurred with different time-courses, since TNF-α was more potent, rapid, and transient than TRAIL. Of the two TRAIL receptors constitutively expressed by HL-60 (TRAIL-R1 and TRAIL-R2), only the former was involved in IκB degradation, as demonstrated by using agonistic anti-TRAIL receptor antibodies. Moreover, NF-κB nuclear translocation induced by TRAIL but not by TNF-α was abrogated by z-IETD-fmk, a caspase-8-specific inhibitor. The key role of NF-κB in mediating the biological effects of TNF-α and TRAIL was demonstrated by the ability of unrelated pharmacological inhibitors of the NF-κB pathway (parthenolide and MG-132) to abrogate TNF-α- and TRAIL-induced monocytic maturation. These findings demonstrate that NF-κB is essential for monocytic maturation and is activated via distinct pathways, involving or not involving caspases, by the related cytokines TRAIL and TNF-α.
Inhibition of myeloid cell differentiation in cancer: the role of reactive oxygen species
Authors: Kusmartsev Sergei , Gabrilovich Dmitry I 
Published: July 2003

Abstract
It is well established that tumor growth is associated with accumulation of immature myeloid cells (ImC). They play an important role in tumor-associated immune suppression. ImC accumulate not only in tumor-bearing hosts but also in immunized, tumor-free hosts or hosts infected with bacterial pathogens. The kinetics of ImC in these mice is different. If in tumor-bearing mice, the number of ImC continues to increase with tumor progression in tumor-free mice after an initial spike, it decreases to the control level. Here, we have investigated the mechanisms of ImC accumulation in tumor-bearing hosts by comparing differentiation of ImC obtained from tumor-free and tumor-bearing mice. In the presence of appropriate growth factors, ImC isolated from tumor-free mice quickly differentiated in vitro into mature dendritic cells (DC), macrophages, and granulocytes. In contrast, differentiation of ImC from tumor-bearing mice was significantly delayed. Similar results were obtained in vivo after adoptive transfer of ImC into naïve, congeneic mice. ImC transferred into tumor-bearing recipients failed to differentiate into DC or macrophages. ImC from tumor-bearing mice had significantly higher levels of reactive oxygen species (ROS) than ImC obtained from tumor-free mice. Hydrogen peroxide (H2O2) but not superoxide radical anions was found to be the major part of this increased ROS production. In vitro experiments demonstrated that scavenging of H2O2 with catalase induced differentiation of ImC from tumor-bearing mice into macrophages. Thus, this is a first demonstration that tumors may prevent differentiation of antigen-presenting cells by increasing the level of endogenous H2O2 in immature myeloid cells.
Dramatic increase of telomerase activity during dendritic cell differentiation and maturation
Authors: Ping Lin , Asai Azusa , Okada Aki , Isobe Kenichi , Nakajima Hideo 
Published: July 2003

Abstract
Telomerase, the reverse transcriptase that maintains telomere DNA, is usually undetectable in most adult tissues but is positive in embryonic tissues and in cancers. In addition, freshly islolated or in vitro-activated lymphocytes were shown to express high levels of telomerase activity, although its expression in myeloid cells including dendritic cells (DCs) is largely unknown. Here, we investigated telomerase activity during the differentiation and maturation process of DCs. In vitro culture of bone marrow (BM) cells with granulocyte macrophage-colony stimulating factor and interleukin-4 induced a dramatic increase of telomerase activity accompanied with their differentiation into DCs. Furthermore, stimulation with microbial components such as lipopolysaccharide (LPS), which triggers maturation of DCs, augmented the activity. In vivo responses of telomerase activity were also observed in splenic DCs by injection of LPS intraperitoneally. It is interesting that in old mice, telomerase activity of splenic DCs was significantly higher than young mice but rather decreased after LPS stimulation. By measuring expression of cell-surface activation markers, splenic DCs of old mice responded poorly to LPS stimulation. Such poor responses to LPS were also observed in BM-derived DCs. These different features of DCs between young and old mice may contribute to a pathogenesis to microbial infections.
TLR2 and TLR4 serve distinct roles in the host immune response against Mycobacterium bovis BCG
Authors: Heldwein Kurt A , Liang Michael D , Andresen Tonje K , Thomas Karen E , Marty Aileen M , Cuesta Natalia , Vogel Stefanie N , Fenton Matthew J 
Published: July 2003

Abstract
Toll-like receptor (TLR) proteins mediate cellular activation by microbes and microbial products. To delineate the role of TLR proteins in the development of host immune responses against mycobacteria, wild-type and TLR-deficient mice were infected with nonpathogenic Mycobacterium bovis bacillus Calmette-Guerin (BCG). Two weeks after intraperitoneal challenge with BCG, few bacilli were present in the lungs of wild-type and TLR4−/− mice, whereas bacterial loads were tenfold higher in the lungs of infected TLR2−/− mice. BCG challenge in vitro strongly induced proinflammatory cytokine secretion by macrophages from wild-type and TLR4−/− mice but not by TLR2−/− macrophages. In contrast, intracellular uptake, intracellular bacterial growth, and suppression of intracellular bacterial growth in vitro by interferon-γ (IFN-γ) were similar in macrophages from all three mouse strains, suggesting that BCG growth in the lungs of TLR2−/− mice was a consequence of defective adaptive immunity. Antigenic stimulation of splenocytes from infected wild-type and TLR4−/− mice induced T cell proliferation in vitro, whereas T cells from TLR2−/− mice failed to proliferate. Unexpectedly, activated CD4+ T cells from both TLR-deficient mouse strains secreted little IFN-γ in vitro compared with control T cells. A role for TLR4 in the control of bacterial growth and IFN-γ production in vivo was observed only when mice were infected with higher numbers of BCG. Thus, TLR2 and TLR4 appear to regulate distinct aspects of the host immune response against BCG.
Retinal transplantation: progress and problems in clinical application
Authors: Lund R D , Ono S J , Keegan D J , Lawrence J M 
Published: July 2003

Abstract
There is currently no real treatment for blinding disorders that stem from the degeneration of cells in the retina and affect at least 50 million individuals worldwide. The excitement that accompanied the first studies showing the potential of retinal cell transplantation to alleviate the progress of blindness in such diseases as retinitis pigmentosa and age-related macular degeneration has lost some of its momentum, as attempts to apply research to the clinic have failed so far to provide effective treatments. What these studies have shown, however, is not that the approach is flawed but rather that the steps that need to be taken to achieve a viable, clinical treatment are many. This review summarizes the course of retinal transplant studies and points to obstacles that still need to be overcome to improve graft survival and efficacy and to develop a protocol that is effective in a clinical setting. Emphasis is given particularly to the consequences of introducing transplants to sites that have been considered immunologically privileged and to the role of the major histocompatibility complex classes I and II molecules in graft survival and rejection.