bluuebunny/crossref_metadata_2025_split huggingface dataset:
HLA-A2 Supertype-Restricted Cell-Mediated Immunity by Peripheral Blood Mononuclear Cells Derived from Malian Children with Severe or UncomplicatedPlasmodium falciparumMalaria and Healthy Controls
Authors: Lyke Kirsten E. , Burges Robin B. , Cissoko Yacouba , Sangare Lansana , Kone Abdoulaye , Dao Modibo , Diarra Issa , Fernández-Viňa Marcelo A. , Plowe Christopher V. , Doumbo Ogobara K. , Sztein Marcelo B. 
Published: August 2005

ABSTRACTUnderstanding HLA-restricted adaptive host immunity to defined epitopes of malarial antigens may be required for the development of successful malaria vaccines. Fourteen epitopes of preerythrocytic malarial antigens known to mediate cytotoxic T-lymphocyte responses against target cells expressing HLA-A2-restricted epitopes were synthesized and pooled based on antigen: thrombospondin-related anonymous protein (TRAP), circumsporozoite protein (CSP), and export protein 1 (Exp-1) peptides. HLA-A2 supertype (*0201, *0202, *0205, *6802) peripheral blood mononuclear cells collected from 774 Malian children, aged 3 months to 14 years, with severePlasmodium falciparummalaria matched to uncomplicated malaria or healthy controls were stimulated with the HLA-A2-restricted peptide pools. Significant gamma interferon production, determined by enzyme-linked immunospot assay to at least one of the three peptide pools, was observed in 24/58 (41%) of the severe malaria cases, 24/57 (42%) of the uncomplicated malaria cases, and 34/51 (67%) of the healthy controls. Significant lymphoproliferation to these peptides was observed in 12/44 (27%) of the severe malaria cases, 13/55 (24%) of the uncomplicated malaria cases, and 18/50 (36%) of the healthy controls. Responses to individual peptide pools were limited. These studies confirm the presence of adaptive cell-mediated immunity to preerythrocytic malaria antigens in volunteers from Mali and demonstrate that suballeles of the HLA-A2 supertype can effectively present antigenic epitopes. However, whether these immune responses to TRAP, CSP, and Exp-1 malarial proteins play a substantial role in protection remains a matter of controversy.
Placental Malaria Induces Variant-Specific Antibodies of the Cytophilic Subtypes Immunoglobulin G1 (IgG1) and IgG3 That Correlate with Adhesion Inhibitory Activity
Authors: Elliott Salenna R. , Brennan Amy K. , Beeson James G. , Tadesse Eyob , Molyneux Malcolm E. , Brown Graham V. , Rogerson Stephen J. 
Published: August 2005

ABSTRACT

Antibodies targeting variant antigens on the surfaces of chondroitin sulfate A (CSA)-binding malaria-infected erythrocytes have been linked to protection against the complications of malaria in pregnancy. We examined the isotype/subtype profiles of antibodies that bound to variant surface antigens expressed by CSA-adherent
Plasmodium falciparum
in pregnant Malawian women with and without histologically defined placental malaria. Women in their first pregnancy with placental malaria produced significantly greater amounts of immunoglobulin G1 (IgG1) and IgG3 reactive with surface antigens of malaria-infected erythrocytes than uninfected women of the same gravidity. IgG1 and IgG3 levels in infected and control women in later pregnancies were similar to those in infected women in their first pregnancy. Levels of IgG2 and IgG4 were similarly low in infected and uninfected women of all gravidities. IgM that bound to the surface of CSA-adherent
P. falciparum
occurred in all groups of women and malaria-naïve controls. There was a significant correlation between IgG1 and IgG3 levels, indicating that women usually produced both subtypes. Levels of IgG1 and IgG3 correlated with the ability of serum or plasma to inhibit parasite adhesion to CSA. Taken together, these data suggest that IgG1 and IgG3 dominate the IgG response to placental-type variant surface antigens. They may function by blocking parasite adhesion to placental CSA, but given their cytophilic nature, they might also opsonize malaria-infected erythrocytes for interaction with Fc receptors on phagocytic cells.
Transforming Growth Factor β1 Production by CD4+CD25+Regulatory T Cells in Peripheral Blood Mononuclear Cells from Healthy Subjects Stimulated withLeishmania guyanensis
Authors: Kariminia A. , Bourreau E. , Pascalis H. , Couppié P. , Sainte-Marie D. , Tacchini-Cottier F. , Launois P. 
Published: August 2005

ABSTRACTTransforming growth factor β (TGF-β) has been shown to be a central immunomodulator used by leishmaniae to escape effective mechanisms of protection in human and murine infections with these parasites. However, all the information is derived from studies of established infection, while little is known about TGF-β production in response toLeishmaniastimulation in healthy subjects. In this study, TGF-β1 production was demonstrated in peripheral blood mononuclear cells from healthy subjects never exposed to leishmaniae in response to liveLeishmania guyanensis, and the TGF-β1-producing cells were described as a distinct subpopulation of CD4+CD25+regulatory T cells. The suppressive properties of CD4+CD25+T cells were demonstrated in vitro by their inhibition of production of interleukin 2 (IL-2) and IL-10 by CD4+CD25−T cells in the presence of either anti-CD3 orL. guyanensis. Although neutralization of TGF-β1 did not reverse the suppressive activity of CD4+CD25+T cells activated by anti-CD3, it reversed the suppressive activity of CD4+CD25+T cells activated byL. guyanensis. Altogether our data demonstrated that TGF-β1 is involved in the suppressive activity ofL. guyanensis-stimulated CD4+CD25+T cells from healthy controls.
Quantitative Assessment of Protection in Experimental Syphilis
Authors: Champion Cheryl I. , Blanco David R. , Lovett Michael A. 
Published: August 2005

ABSTRACTProtection in experimental rabbit syphilis has been previously assessed by lesion development following intradermal challenge withTreponema pallidum. We have recently reported that passive immunization using monoclonal antibody M131 conveys partial protection as evidenced by significant lesion delays following intradermal challenge (D. R. Blanco et al., Infect. Immun.73:3083-3095, 2005). To determine whether such delays in time to lesion appearance corresponded to decreases in the numbers of spirochetes, we used real-time PCR to quantitateT. pallidumgenomic DNA copy numbers in lesion biopsies taken throughout the course of lesion development. Three groups of animals were given one prechallenge passive immunization with immune rabbit serum (IRS), M131, or control monoclonal antibody (CMAb) and then challenged with treponemal admixtures of IRS or monoclonal antibody in normal rabbit serum (NRS). As compared to the CMAb NRS controls, delays in the mean time to lesion appearance of 5.8 days for IRS and 8.8 days for M131 were observed. At the earliest time point (10 days postchallenge), real-time PCR showed a meanT. pallidumDNA copy number per μg of rabbit DNA in the CMAb NRS group of 7.65 × 103copies, while noT. pallidumDNA could be detected in the M131 group. At approximately the mean time to lesion appearance in the IRS and M131 groups (17 and 20 days, respectively), the numbers ofT. pallidumDNA copies were still 5- and 30-fold less, respectively, than those in the control group at these times. By 30 days postchallenge, theT. pallidumDNA copy numbers were similar in all three groups. These findings indicate that the delays in appearance of syphilitic lesions conferred by IRS and M131 corresponded to a marked decrease in treponemal numbers during the course of lesion development.
Extensive Antigenic Polymorphism within the Repeat Sequence of thePlasmodium falciparumMerozoite Surface Protein 1 Block 2 Is Incorporated in a Minimal Polyvalent Immunogen
Authors: Tetteh Kevin K. A. , Cavanagh David R. , Corran Patrick , Musonda Rosemary , McBride Jana S. , Conway David J. 
Published: August 2005

ABSTRACTPolymorphism in pathogen antigens presents a complex challenge for vaccine design. A prime example is the N-terminal block 2 region of thePlasmodium falciparummerozoite surface protein 1 (MSP1), to which allele-specific antibodies have been associated with protection from malaria. In a Zambian population studied here, 49 of 91 alleles sampled were of the K1-like type (the most common of three block 2 types in all African populations), and most of these had unique sequences due to variation in tri- and hexapeptide repetitive motifs. There were significant negative correlations between allelic sequence lengths of different regions of the repeats, so the complete repeat sequence had less length variation than its component parts, suggesting a constraint on overall length. Diverse epitopes recognized by three murine monoclonal antibodies and 24 individual human sera were then mapped by using a comprehensive panel of synthetic peptides, revealing epitopes in all regions of the repeats. To incorporate these different epitopes in a single molecule, a composite sequence of minimal overall length (78 amino acids) was then designed and expressed as a recombinant antigen. More human immune sera reacted with this “K1-like Super Repeat” antigen than with proteins consisting of single natural allelic sequences, and immunization of mice elicited antibodies that recognized a range of five cultured parasite lines with diverse K1-like MSP1 block 2 repeat sequences. Thus, complex allelic polymorphism was deconstructed and a minimal composite polyvalent antigen was engineered, delivering a designed candidate sequence for inclusion in a malaria vaccine.
Synergy in Polymicrobial Infections in a Mouse Model of Type 2 Diabetes
Authors: Mastropaolo Matthew D. , Evans Nicholas P. , Byrnes Meghan K. , Stevens Ann M. , Robertson John L. , Melville Stephen B. 
Published: August 2005

ABSTRACTHuman diabetics frequently suffer delayed wound healing, increased susceptibility to localized and systemic infections, and limb amputations as a consequence of the disease. Lower-limb infections in diabetic patients are most often polymicrobial, involving mixtures of aerobic, facultative anaerobic, and anaerobic bacteria. The purpose of this study is to determine if these organisms contribute to synergy in polymicrobial infections by using diabetic mice as an in vivo model. The model was the obese diabetic mouse strain BKS.Cg-m+/+Leprdb/J, a model of human type 2 diabetes. Young (5- to 6-week-old) prediabetic mice and aged (23- to 24-week-old) diabetic mice were compared. The mice were injected subcutaneously with mixed cultures containingEscherichia coli,Bacteroides fragilis, andClostridium perfringens. Progression of the infection (usually abscess formation) was monitored by examining mice for bacterial populations and numbers of white blood cells at 1, 8, and 22 days postinfection. Synergy in the mixed infections was defined as a statistically significant increase in the number of bacteria at the site of injection when coinfected with a second bacterium, compared to when the bacterium was inoculated alone.E. coliprovided strong synergy toB. fragilisbut not toC. perfringens. C. perfringensandB. fragilisprovided moderate synergy to each other but only in young mice.B. fragiliswas anergistic (antagonistic) toE. coliin coinfections in young mice at 22 days postinfection. When age-matched nondiabetic mice (C57BLKS/J) were used as controls, the diabetic mice exhibited 5 to 35 times the number of CFU as did the nondiabetic mice, indicating that diabetes was a significant factor in the severity of the polymicrobial infections.
Stability-Dependent Exchange Coefficients for Air–Sea Fluxes*
Authors: Kara A. Birol , Hurlburt Harley E. , Wallcraft Alan J. 
Published: August 2005

Abstract
This study introduces exchange coefficients for wind stress (CD), latent heat flux (CL), and sensible heat flux (CS) over the global ocean. They are obtained from the state-of-the-art Coupled Ocean–Atmosphere Response Experiment (COARE) bulk algorithm (version 3.0). Using the exchange coefficients from this bulk scheme, CD, CL, and CS are then expressed as simple polynomial functions of air–sea temperature difference (Ta − Ts)—where air temperature (Ta) is at 10 m, wind speed (Va) is at 10 m, and relative humidity (RH) is at the air–sea interface—to parameterize stability. The advantage of using polynomial-based exchange coefficients is that they do not require any iterations for stability. In addition, they agree with results from the COARE algorithm but at ≈5 times lower computation cost, an advantage that is particularly needed for ocean general circulation models (OGCMs) and climate models running at high horizontal resolution and short time steps. The effects of any water vapor flux in calculating the exchange coefficients are taken into account in the polynomial functions, a feature that is especially important at low wind speeds (e.g., Va &lt; 5 m s−1) because air–sea mixing ratio difference can have a major effect on the stability, particularly in tropical regions. Analyses of exchange coefficients demonstrate the fact that water vapor can have substantial impact on air–sea exchange coefficients at low wind speeds. An example application of the exchange coefficients from the polynomial approach is the recalculation of climatological mean wind stress magnitude from 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data in the North Pacific Ocean over 1979–2002. Using ECMWF 10-m winds and the authors’ methodology provides accurate surface stresses while largely eliminating the orographically induced Gibb’s waves found in the original ERA-40 surface wind stresses. These can have a large amplitude near mountainous regions and can extend far into the ocean interior. This study introduces exchange coefficients of air–sea fluxes, which are applicable to the wide range of conditions occurring over the global ocean, including the air–sea stability differences across the Gulf Stream and Kuroshio, regions which have been the subject of many climate model studies. This versatility results because CD, CL, and CS are determined for Va values of 1 to 40 m s−1, (Ta − Ts), intervals of −8° to 7°C, and RH values of 0% to 100%. Exchange coefficients presented here are called the Naval Research Laboratory (NRL) Air–Sea Exchange Coefficients (NASEC) and they are suitable for a wide range of air–sea interaction studies and model applications.
Monitoring the Reflectivity Calibration of a Scanning Radar Using a Profiling Radar and a Disdrometer
Authors: Williams Christopher R. , Gage Kenneth S. , Clark Wallace , Kucera Paul 
Published: August 2005

Abstract
This paper describes a method of absolutely calibrating and routinely monitoring the reflectivity calibration from a scanning weather radar using a vertically profiling radar that has been absolutely calibrated using a collocated surface disdrometer. The three instruments have different temporal and spatial resolutions, and the concept of upscaling is used to relate the small resolution volume disdrometer observations with the large resolution volume scanning radar observations. This study uses observations collected from a surface disdrometer, two profiling radars, and the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) scanning weather radar during the Texas–Florida Underflight-phase B (TEFLUN-B) ground validation field campaign held in central Florida during August and September 1998.
The statistics from the 2062 matched profiling and scanning radar observations during this 2-month period indicate that the WSR-88D radar had a reflectivity 0.7 dBZ higher than the disdrometer-calibrated profiler, the standard deviation was 2.4 dBZ, and the 95% confidence interval was 0.1 dBZ. This study implies that although there is large variability between individual matched observations, the precision of a series of observations is good, allowing meaningful comparisons useful for calibration and monitoring.
Damaging Surface Wind Mechanisms within the 10 June 2003 Saint Louis Bow Echo during BAMEX
Authors: Atkins Nolan T. , Bouchard Christopher S. , Przybylinski Ron W. , Trapp Robert J. , Schmocker Gary 
Published: August 2005

Abstract
Detailed radar and damage survey analyses of a severe bow echo event that occurred on 10 June 2003 during the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment are presented. A bow echo formed just east of Saint Louis, Missouri, and produced a continuous straight-line wind damage swath approximately 8 km in width and 50 km in length along with five F0–F1 tornadoes. Careful superposition of the damage survey analysis and Weather Surveillance Radar-1988 Doppler (WSR-88D) data from Saint Charles, Missouri (KLSX), showed that the primary straight-line wind damage swath was not collocated with the bow echo apex as has been suggested in previous studies. Rather, the primary damage swath was found north of the bow apex, collocated with a low-level vortex that formed on the leading edge of the bow echo. Much of the primary damage swath appeared to have been created by the low-level vortex. Moreover, most of the surface straight-line wind damage was generated during the early stages of bow echo morphology prior to when the radar-detected bow echo attributes were best defined.
Detailed analysis of the KLSX radar data revealed the genesis of 11 low-level meso-γ-scale vortices within the convective system. Superposition of the damage survey data showed that five of the vortices were tornadic. Careful analysis of the radar data suggests that it may be possible to distinguish between the tornadic and nontornadic vortices. Consistently, the tornadic vortices were longer-lived and stronger at low levels [0–3 km above ground level (AGL)] and rapidly deepened and intensified just prior to tornadogenesis. Similar evolution was not observed with the nontornadic vortices. All of the tornadic vortices formed coincident with or after the genesis time of the rear-inflow jet. These results suggest that the rear-inflow jet may be important for creating tornadic vortices within bow echoes. The detection and warning implications of these results are discussed.
Evaluation of Heavy Precipitation Forecasts Using Composite-Based Methods: A Distributions-Oriented Approach
Authors: Nachamkin Jason E. , Chen Sue , Schmidt Jerome 
Published: August 2005

Abstract
Numerical forecasts of heavy warm-season precipitation events are verified using simple composite collection techniques. Various sampling methods and statistical measures are employed to evaluate the general characteristics of the precipitation forecasts. High natural variability is investigated in terms of its effects on the relevance of the resultant statistics. Natural variability decreases the ability of a verification scheme to discriminate between systematic and random error. The effects of natural variability can be mitigated by compositing multiple events with similar properties. However, considerable sample variance is inevitable because of the extreme diversity of mesoscale precipitation structures.
The results indicate that forecasts of heavy precipitation were often correct in that heavy precipitation was observed relatively close to the predicted area. However, many heavy events were missed due in part to the poor prediction of convection. Targeted composites of the missed events indicate that a large percentage of the poor forecasts were dominated by convectively parameterized precipitation. Further results indicate that a systematic northward bias in the predicted precipitation maxima is related to the deficits in the prediction of subsynoptically forced convection.
The Santa Cruz Eddy. Part II: Mechanisms of Formation
Authors: Archer Cristina L. , Jacobson Mark Z. 
Published: August 2005

Abstract
The formation mechanism of the Santa Cruz eddy (SCE) is investigated using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5). Simulations of 25–26 August 2000 showed that two eddy instances formed on that night, a finding supported by observations. The two eddies had similar behavior: they both formed in the sheltered Santa Cruz, California, area and then moved southeastward, to finally dissipate after 7–11 h. However, the first eddy had greater vorticity, wind speed, horizontal and vertical extents, and lifetime than the second eddy. Numerical simulations showed that the SCEs are formed by the interaction of the main northwesterly flow with the topographic barrier represented by the Santa Cruz Mountains to the north of Monterey Bay. Additional numerical experiments were undertaken with no diurnal heating cycle, no (molecular or eddy) viscosity, and no horizontal thermal gradients at ground level. In all cases, vertical vorticity was still created by the tilting of horizontal vorticity generated by the solenoidal term in the vorticity equation. This baroclinic process appeared to be the fundamental formation mechanism for both SCEs, but more favorable conditions in the late afternoon (including a south-to-north pressure gradient, flow turning due to the sea breeze, and an expansion fan) coincided to intensify the first eddy.
Applicability of Large-Scale Convection and Condensation Parameterization to Meso-γ-Scale HIRLAM: A Case Study of a Convective Event
Authors: Niemelä Sami , Fortelius Carl 
Published: August 2005

Abstract
This paper presents a case study of a single cold air outbreak event with widespread convective precipitation over southern Finland on 25 May 2001. The purpose of the study is to investigate the applicability of the convection and condensation scheme of the High-Resolution Limited Area Model (HIRLAM) on meso-γ-scales. The study concentrates on the issue of grid-size-dependent convection parameterization. An explicit approach without the convection scheme is also examined. At the same time, the performance of an experimental nonhydrostatic version of HIRLAM is evaluated. Model simulations are conducted with three different horizontal grid spacings: 11, 5.6, and 2.8 km. Model results are compared to observed radar reflectivity data utilizing a radar simulation model, which calculates radar reflectivities from three-dimensional model output.
The best results are obtained using nonhydrostatic dynamics and a grid-size-dependent convection scheme with a 5.6-km grid interval. However, even the best configuration still overestimates the area of strong reflectivity (intense precipitation). All the other combinations produce even stronger reflectivity. The grid-size-dependent convection parameterization is evidently beneficial at smaller grid spacings than 5.6 km. The nonhydrostatic model clearly outperforms its hydrostatic counterpart at the 5.6- and 2.8-km grid spacings, whereas with an 11-km grid interval, both models perform equally well.
Analysis of Discrete Shallow-Water Models on Geodesic Delaunay Grids with C-Type Staggering
Authors: Bonaventura Luca , Ringler Todd 
Published: August 2005

AbstractThe properties of C-grid staggered spatial discretizations of the shallow-water equations on regular Delaunay triangulations on the sphere are analyzed. Mass-conserving schemes that also conserve either energy or potential enstrophy are derived, and their features are analogous to those of the C-grid staggered schemes on quadrilateral grids. Results of numerical tests carried out with explicit and semi-implicit time discretizations show that the potential-enstrophy-conserving scheme is able to reproduce correctly the main features of large-scale atmospheric motion and that power spectra for energy and potential enstrophy obtained in long model integrations display a qualitative behavior similar to that predicted by the decaying turbulence theory for the continuous system.