bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamical and Synoptic Characteristics of Heavy Rainfall Episodes in Southern Brazil
Authors: Teixeira Mateusda Silva , Satyamurty Prakki 
Published: February 2007

Abstract
The dynamical and synoptic characteristics that distinguish heavy rainfall episodes from nonheavy rainfall episodes in southern Brazil are discussed. A heavy rainfall episode is defined here as one in which the 50 mm day−1 isohyet encloses an area of not less than 10 000 km2 in the domain of southern Brazil. One hundred and seventy such events are identified in the 11-yr period of 1991–2001. The mean flow patterns in the period of 1–3 days preceding the episodes show some striking synoptic-scale features that may be considered forerunners of these episodes: (i) a deepening midtropospheric trough in the eastern South Pacific approaches the continent 3 days before, (ii) a surface low pressure center forms in northern Argentina 1 day before, (iii) a northerly low-level jet develops over Paraguay 2 days before, and (iv) a strong moisture flux convergence over southern Brazil becomes prominent 1 day before the episode. A parameter called rainfall quantity, defined as the product of the area enclosed by the 50 mm day−1 isohyet and the average rainfall intensity, is correlated with fields of atmospheric variables such as 500-hPa geopotential and 850-hPa meridional winds. Significant lag correlations show that the anomalies of some atmospheric variables could be viewed as precursors of heavy rainfall in southern Brazil that can be explored for use in improving the forecasts.
Effect of Convective Entrainment/Detrainment on the Simulation of the Tropical Precipitation Diurnal Cycle*
Authors: Wang Yuqing , Zhou Li , Hamilton Kevin 
Published: February 2007

Abstract
A regional atmospheric model (RegCM) developed at the International Pacific Research Center (IPRC) is used to investigate the effect of assumed fractional convective entrainment/detrainment rates in the Tiedtke mass flux convective parameterization scheme on the simulated diurnal cycle of precipitation over the Maritime Continent region. Results are compared with observations based on 7 yr of the Tropical Rainfall Measuring Mission (TRMM) satellite measurements. In a control experiment with the default fractional convective entrainment/detrainment rates, the model produces results typical of most other current regional and global atmospheric models, namely a diurnal cycle with precipitation rates over land that peak too early in the day and with an unrealistically large diurnal range. Two sensitivity experiments were conducted in which the fractional entrainment/detrainment rates were increased in the deep and shallow convection parameterizations, respectively. Both of these modifications slightly delay the time of the rainfall-rate peak during the day and reduce the diurnal amplitude of precipitation, thus improving the simulation of precipitation diurnal cycle to some degree, but better results are obtained when the assumed entrainment/detrainment rates for shallow convection are increased to the value consistent with the published results from a large eddy simulation (LES) study. It is shown that increasing the entrainment/detrainment rates would prolong the development and reduce the strength of deep convection, thus delaying the mature phase and reducing the amplitude of the convective precipitation diurnal cycle over the land. In addition to the improvement in the simulation of the precipitation diurnal cycle, convective entrainment/detrainment rates also affect the simulation of temporal variability of daily mean precipitation and the partitioning of stratiform and convective rainfall in the model. The simulation of the observed offshore migration of the diurnal signal is realistic in some regions but is poor in some other regions. This discrepancy seems not to be related to the convective lateral entrainment/detrainment rate but could be due to the insufficient model resolution used in this study that is too coarse to resolve the complex land–sea contrast.
Sensitivities of a Flash Flood Event over Catalonia: A Numerical Analysis
Authors: Martín A. , Romero R. , De Luque A. , Alonso S. , Rigo T. , Llasat M. C. 
Published: February 2007

AbstractOn 9 and 10 June 2000, the northeastern part of the Iberian Peninsula was affected by heavy rains that produced severe floods over densely populated areas. The zones most affected were the provinces of Tarragona and Barcelona, located in the region of Catalonia. Five people were killed, 500 were evacuated, and the property losses were estimated to exceed 65 million euros. The episode was characterized by the entrance of an Atlantic low-level cold front and an upper-level trough that contributed to the generation of a mesoscale cyclone in the Mediterranean Sea east of mainland Spain. The circulation associated with this mesoscale cyclone advected warm and moist air toward Catalonia from the Mediterranean Sea. The convergence zone between the easterly flow and the Atlantic front, as well as the complex orography of the region, are shown to be involved in the triggering and organization of the convective systems. Radar shows the development of two long-lived mesoscale convective systems that merged and remained quasi-stationary nearby the city of Barcelona for nearly 2 h.The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) short-range numerical simulations of the episode succeed reasonably well in capturing the accumulated rainfall patterns and important mesoscale aspects of the event. The role of the orography and latent heat release in generating and sustaining the quasi-stationary precipitating systems is assessed through numerical sensitivity analysis. A piecewise potential vorticity inversion technique, assisted by sensitivity fields derived from an adjoint model, provides a test bed to investigate the predictability of the damaging rains given uncertainties in the initial fields. The adjoint results highlight the importance of the details associated with the upper-level precursor trough. Therefore, the effects of small perturbations to the trough intensity and location are also investigated. Interestingly, despite the orography’s active role in the generation of the Mediterranean mesoscale cyclone and, hence, on the location of the precipitation maxima, the predictability of the spatial and temporal distribution and amounts of precipitation is shorter than might be expected. This reduced predictability of the rainfall field is attributed to the high sensitivity of the location and depth of the mesoscale cyclone identified in the Mediterranean Sea east of Catalonia to perturbations; that is, to the location and intensity of the precursor upper-level trough, compatible with realistic analysis errors.
Non-Gaussianity and Asymmetry of the Winter Monthly Precipitation Estimation from the NAO
Authors: Pires Carlos A. , Perdigão Rui A. P. 
Published: February 2007

Abstract
The present work assesses non-Gaussianity and asymmetry within the statistical response of the monthly winter (December–February) precipitation to the North Atlantic Oscillation (NAO) over the North Atlantic–European region (NAE). To evaluate asymmetry, data are split through the median of the NAO index and side correlations are computed for each regime [negative and positive phases of the NAO (NAO− and NAO+, respectively)]. The following statistically significant differences between these correlations are found: (a) near the central North Atlantic, around 40°N, 20°W, and southeast of Iceland, with much stronger correlations in the wet-favorable regime: NAO− in the first location and NAO+ in the second location; (b) around 42°N, 48°W in the west North Atlantic; and (c) south of Greenland and in the west Mediterranean near 36°N, where, in both cases, the correlation is only relevant for the dry-favorable NAO+ regime. Based on the above decomposition, a map of a statistical test of asymmetry, applicable for every bivariate distribution, is shown.
To evaluate redundancy and non-Gaussianity, the mutual information (MI) is computed from information theory. Its positive contributions resulting from the linear correlation, a purely Gaussian term, and non-Gaussianity, which vanishes in pure Gaussian cases, are studied. The MI is estimated through two methods: 1) the truncated Edgeworth expansion of the bivariate probability density function in terms of Hermite polynomials and cumulants, and 2) the maximum entropy method. This method is quite general, while the first one is only applicable for small deviations from Gaussianity. The map of non-Gaussian MI over the NAE domain reveals some coherent regions, where the nonlinear component of the response of monthly winter precipitation to the NAO is more important. The MI is evaluated both for the original pair of variables and for that pair after being subjected to Gaussian anamorphosis in order to prevent the influence of marginal outliers and keep the applicability of the Edgeworth method.
C-KIT, by interacting with the membrane-bound ligand, recruits endothelial progenitor cells to inflamed endothelium
Authors: Dentelli Patrizia , Rosso Arturo , Balsamo Antonina , Colmenares Benedetto Sofia , Zeoli Annarita , Pegoraro Marco , Camussi Giovanni , Pegoraro Luigi , Brizzi Maria Felice 
Published: February 2007

AbstractWe investigated the role of c-Kit and the membrane-bound ligand (mbKitL) in endothelial progenitor cell (EPC) recruitment by microvascular endothelial cells (ECs). We demonstrated that inflammatory activation induced the expression of the mbKitL on ECs both in vitro and in vivo, and that recruitment of EPCs depended on c-Kit/mbKitL interaction. Depletion of endogenous c-Kit or inhibition of c-Kit enzymatic activity by imatinib mesylate prevented adhesion of EPCs to activated ECs both in vitro and in vivo, indicating that a functional c-Kit on EPCs is essential. We also demonstrate that Akt was the downstream molecule regulating cell adhesion. A potential role of the c-Kit/mbKitL interaction in pathological settings is sustained by the expression of the mbKitL on ECs lining intraplaque neovessels. Thus, our results provide new insights into the mechanisms underlying EPC recruitment and the bases for novel strategies to hinder pathological angiogenesis.
Blood and lymphatic endothelial cell-specific differentiation programs are stringently controlled by the tissue environment
Authors: Amatschek Stefan , Kriehuber Ernst , Bauer Wolfgang , Reininger Barbel , Meraner Paul , Wolpl Alois , Schweifer Norbert , Haslinger Christian , Stingl Georg , Maurer Dieter 
Published: February 2007

AbstractThe discovery of marker proteins of human blood (BECs) and lymphatic endothelial cells (LECs) has allowed researchers to isolate these cells. So far, efforts to unravel their transcriptional and functional programs made use of cultured cells only. Hence, it is unknown to which extent previously identified LEC- and BEC-specific programs are representative of the in vivo situation. Here, we define the human BEC- and LEC-specific in vivo transcriptomes by comparative genomewide expression profiling of freshly isolated cutaneous EC subsets and of non-EC skin cells (fibroblasts, mast cells, dendritic cells, epithelial cells). Interestingly, the expression of most of the newly identified EC subset-discriminating genes depends strictly on the in vivo tissue environment as revealed by comparative analyses of freshly isolated and cultured EC subsets. The identified environment-dependent, EC subset-restricted gene expression regulates lineage fidelity, fluid exchange, and MHC class II–dependent antigen presentation. As an example for a BEC-restricted in vivo function, we show that non-activated BECs in situ, but not in vitro, assemble and display MHC class II protein complexes loaded with self-peptides. Thus, our data demonstrate the key importance of using precisely defined native ECs for the global identification of in vivo relevant cell functions.
Abnormal activation and cytokine spectra in lymph nodes of people chronically infected with HIV-1
Authors: Biancotto Angélique , Grivel Jean-Charles , Iglehart Sarah J. , Vanpouille Christophe , Lisco Andrea , Sieg Scott F. , Debernardo Robert , Garate Kristen , Rodriguez Benigno , Margolis Leonid B. , Lederman Michael M. 
Published: February 2007

AbstractThere is growing recognition that HIV-1 infection leads to an activation of the immune system that includes perturbations of cytokine expression, redistribution of lymphocyte subpopulations, cell dysfunction, and cell death. Here, we explored the relationships between HIV-1 infection and immune activation in chronically HIV-1–infected human lymph nodes. In addition to CD4 T-cell depletion, we found increased effector T-cell frequencies associated with profound up-regulation of an activation marker CD38 in naive, central memory, and effector CD4+ and CD8+ T cells. Likewise, Fas death receptor (CD95) was more frequently detectable on T cells from HIV-1 nodes. Dendritic cell (DC) depletion was dramatic, with plasmacytoid DCs (PDCs) 40-fold and myeloid DCs (MDCs) 20-fold less frequent in HIV+ nodes than in control nodes. Cytokine dysregulation was evident, with IL-2 and IL-15 as much as 2 or 3 logs greater in infected nodes than in control nodes. Thus, activated effector cells are inappropriately attracted and/or retained in lymphoid tissue in chronic HIV-1 infection. High-level cytokine expression in turn activates and retains more cells at these sites, leading to lymphadenopathy and massive bystander activation that characterizes HIV-1 infection. Strategies targeting these activation pathways may lead to new therapies.
Upregulation of pirin expression by chronic cigarette smoking is associated with bronchial epithelial cell apoptosis
Authors: Gelbman Brian D , Heguy Adriana , O'Connor Timothy P , Zabner Joseph , Crystal Ronald G 
Published: February 2007

Abstract

Background
Cigarette smoke disrupts the protective barrier established by the airway epithelium through direct damage to the epithelial cells, leading to cell death. Since the morphology of the airway epithelium of smokers does not typically demonstrate necrosis, the most likely mechanism for epithelial cell death in response to cigarette smoke is apoptosis. We hypothesized that cigarette smoke directly up-regulates expression of apoptotic genes, which could play a role in airway epithelial apoptosis.

Methods
Microarray analysis of airway epithelium obtained by bronchoscopy on matched cohorts of 13 phenotypically normal smokers and 9 non-smokers was used to identify specific genes modulated by smoking that were associated with apoptosis. Among the up-regulated apoptotic genes was pirin (3.1-fold, p < 0.002), an iron-binding nuclear protein and transcription cofactor. In vitro studies using human bronchial cells exposed to cigarette smoke extract (CSE) and an adenovirus vector encoding the pirin cDNA (AdPirin) were performed to test the direct effect of cigarette smoke on pirin expression and the effect of pirin expression on apoptosis.

Results
Quantitative TaqMan RT-PCR confirmed a 2-fold increase in pirin expression in the airway epithelium of smokers compared to non-smokers (p < 0.02). CSE applied to primary human bronchial epithelial cell cultures demonstrated that pirin mRNA levels increase in a time-and concentration-dependent manner (p < 0.03, all conditions compared to controls).
Overexpression of pirin, using the vector AdPirin, in human bronchial epithelial cells was associated with an increase in the number of apoptotic cells assessed by both TUNEL assay (5-fold, p < 0.01) and ELISA for cytoplasmic nucleosomes (19.3-fold, p < 0.01) compared to control adenovirus vector.

Conclusion
These observations suggest that up-regulation of pirin may represent one mechanism by which cigarette smoke induces apoptosis in the airway epithelium, an observation that has implications for the pathogenesis of cigarette smoke-induced diseases.
Phylogenetic analyses of complete mitochondrial genome sequences suggest a basal divergence of the enigmatic rodent Anomalurus
Authors: Horner David S , Lefkimmiatis Konstantinos , Reyes Aurelio , Gissi Carmela , Saccone Cecilia , Pesole Graziano 
Published: February 2007

Abstract

Background
Phylogenetic relationships between Lagomorpha, Rodentia and Primates and their allies (Euarchontoglires) have long been debated. While it is now generally agreed that Rodentia constitutes a monophyletic sister-group of Lagomorpha and that this clade (Glires) is sister to Primates and Dermoptera, higher-level relationships within Rodentia remain contentious.

Results
We have sequenced and performed extensive evolutionary analyses on the mitochondrial genome of the scaly-tailed flying squirrel Anomalurus sp., an enigmatic rodent whose phylogenetic affinities have been obscure and extensively debated. Our phylogenetic analyses of the coding regions of available complete mitochondrial genome sequences from Euarchontoglires suggest that Anomalurus is a sister taxon to the Hystricognathi, and that this clade represents the most basal divergence among sampled Rodentia. Bayesian dating methods incorporating a relaxed molecular clock provide divergence-time estimates which are consistently in agreement with the fossil record and which indicate a rapid radiation within Glires around 60 million years ago.

Conclusion
Taken together, the data presented provide a working hypothesis as to the phylogenetic placement of Anomalurus, underline the utility of mitochondrial sequences in the resolution of even relatively deep divergences and go some way to explaining the difficulty of conclusively resolving higher-level relationships within Glires with available data and methodologies.
Modulation of eosinophil activation in vitro by a nicotinic receptor agonist
Authors: Blanchet Marie-Renée , Langlois Anick , Israël-Assayag Evelyne , Beaulieu Marie-Josée , Ferland Claudine , Laviolette Michel , Cormier Yvon 
Published: February 2007

AbstractNicotinic receptor agonists decreased the infiltration of eosinophils into the lung and airways in a mouse model of asthma. To better understand the mechanisms implicated in this anti-inflammatory phenomenon, the expression of nicotinic acetylcholine receptors (nAChRs) and the effect of dimethylphenylpiperazinium (DMPP), a nonselective nAChR agonist, on human blood eosinophils were studied. The expression of α-3, -4, and -7 nAChR subunits on human blood eosinophils was measured by cell ELISA and immunocytochemistry. mRNA expression for all three subunits was evaluated by quantitative RT-PCR. The effect of DMPP on leukotriene C4 (LTC4) and matrix metalloproteinase-9 (MMP-9) production, eosinophil migration, and intracellular calcium mobilization was measured. The results show that the α-3, -4, and -7 nAChR subunits and mRNAs are expressed by blood eosinophils. In vitro treatment of these cells with various concentrations of DMPP reduced platelet-activating factor (PAF)-induced LTC4 production significantly. DMPP (160 μM) decreased eotaxin, and 5-oxo-6,8,11,14-eicosatetranoic acid induced eosinophil migration through Matrigel by 40.9% and 55.5%, respectively. This effect was reversed by the nAChR antagonist mecamylamine. In addition, DMPP reduced MMP-9 release and the inositol 1,4,5-triphosphate-dependent intracellular calcium increase provoked by PAF. Taken together, these results indicate that functional nAChRs are expressed on eosinophils and that nAChR agonists down-regulate eosinophil function in vitro. These anti-inflammatory effects could be of interest in the treatment of allergic asthma.
Hydrogen sulfide induces the synthesis of proinflammatory cytokines in human monocyte cell line U937 via the ERK-NF-κB pathway
Authors: Zhi Liang , Ang Abel Damien , Zhang Huili , Moore Philip K , Bhatia Madhav 
Published: February 2007

AbstractHydrogen sulfide (H2S) is now considered an endogenous, gaseous mediator, which has been demonstrated to be involved in many inflammatory states. However, the mechanism of its proinflammatory function remains unknown. In the present study, we used IFN-γ-primed human monocyticcell line U937 to investigate the effects of H2S in vitro on monocytes. We found that treatment with the H2S donor, sodium hydrosulfide, led to significant increases in the mRNA expression and protein production of TNF-α, IL-1β, and IL-6 in U937 cells. H2S-triggered monocyte activation was confirmed further by the up-regulation of CD11b expression on the cell surface. We also observed that H2S could induce a rapid degradation of IκBα and subsequent activation of NF-κB p65, and this effect was attenuated by Bay 11-7082, a specific inhibitor of NF-κB. Furthermore, pretreatment of cells with Bay 11-7082 substantially inhibited the secretion of TNF-α, IL-1β, and IL-6 induced by H2S. We also found that H2S stimulated the phosphorylation and activation of ERK1/2, but not of p38 MAPK and JNK, and pretreatment with PD98059, a selective MEK1 antagonist, could inhibit H2S-induced NF-κB activation markedly. Together, our findings suggest for the first time that H2S stimulates the activation of human monocytes with the generation of proinflammatory cytokines, and this response is, at least partially, through the ERK-NF-κB signaling pathway.
Dexrazoxane-Associated Risk for Acute Myeloid Leukemia/Myelodysplastic Syndrome and Other Secondary Malignancies in Pediatric Hodgkin's Disease
Authors: Tebbi Cameron K. , London Wendy B. , Friedman Debra , Villaluna Doojduen , De Alarcon Pedro A. , Constine Louis S. , Mendenhall Nancy Price , Sposto Richard , Chauvenet Allen , Schwartz Cindy L. 
Published: February 2007

Purpose Pediatric Oncology Group (POG) studies 9426 and 9425 evaluated dexrazoxane (DRZ) as a cardiopulmonary protectant during treatment for Hodgkin's disease (HD). We evaluated incidence and risk factors of acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and second malignant neoplasms (SMNs). Patients and Methods Treatment for low- and high-risk HD with doxorubicin, bleomycin, vincristine, and etoposide (ABVE) or dose-intensified ABVE with prednisone and cyclophosphamide (ABVE-PC), respectively, was followed by low-dose radiation. The number of chemotherapy cycles was determined by rapidity of the initial response. Patients were assigned randomly to receive DRZ (n = 239) or no DRZ (n = 239) concomitantly with chemotherapy to evaluate its potential to decrease adverse cardiopulmonary outcomes. Results Ten patients developed SMN. Six of eight patients developed AML/MDS, and both solid tumors (osteosarcoma and papillary thyroid carcinoma) occurred in recipients of DRZ. Eight patients with SMN were first events. With median 58 months' follow-up, 4-year cumulative incidence rate (CIR) for AML/MDS was 2.55% ± 1.0% with DRZ versus 0.85% ± 0.6% in the non-DRZ group (P = .160). For any SMN, the CIR for DRZ was 3.43% ± 1.2% versus CIR for non-DRZ of 0.85% ± 0.6% (P = .060). Among patients receiving DRZ, the standardized incidence rate (SIR) for AML/MDS was 613.6 compared with 202.4 for those not receiving DRZ (P = .0990). The SIR for all SMN was 41.86 with DRZ versus 10.08 without DRZ (P = .0231). Conclusion DRZ is a topoisomerase II inhibitor with a mechanism distinct from etoposide and doxorubicin. Adding DRZ to ABVE and ABVE-PC may have increased the incidence of SMN and AML/MDS.