TY  - JOUR
A1  - Hierro, Rodrigo
A1  - Burgos Fonseca, Y.
A1  - Ramezani Ziarani, Maryam
A1  - Llamedo, P.
A1  - Schmidt, Torsten
A1  - de la Torre, Alejandro
A1  - Alexander, P.
T1  - On the behavior of rainfall maxima at the eastern Andes
JF  - Atmospheric Research
N2  - In this study, we detect high percentile rainfall events in the eastern central Andes, based on Tropical Rainfall Measuring Mission (TRMM) with a spatial resolution of 0.25 × 0.25°, a temporal resolution of 3 h, and for the duration from 2001 to 2018. We identify three areas with high mean accumulated rainfall and analyze their atmospheric behaviour and rainfall characteristics with specific focus on extreme events. Extreme events are defined by events above the 95th percentile of their daily mean accumulated rainfall. Austral summer (DJF) is the period of the year presenting the most frequent extreme events over these three regions. Daily statistics show that the spatial maxima, as well as their associated extreme events, are produced during the night. For the considered period, ERA-Interim reanalysis data, provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) with 0.75° x0.75° spatial and 6-hourly temporal resolutions, were used for the analysis of the meso- and synoptic-scale atmospheric patterns. Night- and day-time differences indicate a nocturnal overload of northerly and northeasterly low-level humidity flows arriving from tropical South America. Under these conditions, cooling descending air from the mountains may find unstable air at the surface, giving place to the development of strong local convection. Another possible mechanism is presented here: a forced ascent of the low-level flow due to the mountains, disrupting the atmospheric stratification and generating vertical displacement of air trajectories. A Principal Component Analysis (PCA) in T-mode is applied to day- and night-time data during the maximum and extreme events. The results show strong correlation areas over each subregion under study during night-time, whereas during day-time no defined patterns are found. This confirms the observed nocturnal behavior of rainfall within these three hotspots.
KW  - South-America
KW  - rainy-season
KW  - part I
KW  - precipitation
KW  - TRMM
KW  - climate
KW  - summer
KW  - circulation
KW  - monsoon
KW  - systems
Y1  - 2019
U6  - https://doi.org/10.1016/j.atmosres.2019.104792
SN  - 0169-8095
VL  - 234
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Sic, Heiko
A1  - Kraus, Helene
A1  - Madl, Josef
A1  - Flittner, Karl-Andreas
A1  - von Muenchow, Audrey Lilly
A1  - Pieper, Kathrin
A1  - Rizzi, Marta
A1  - Kienzler, Anne-Kathrin
A1  - Ayata, Korcan
A1  - Rauer, Sebastian
A1  - Kleuser, Burkhard
A1  - Salzer, Ulrich
A1  - Burger, Meike
A1  - Zirlik, Katja
A1  - Lougaris, Vassilios
A1  - Plebani, Alessandro
A1  - Roemer, Winfried
A1  - Loeffler, Christoph
A1  - Scaramuzza, Samantha
A1  - Villa, Anna
A1  - Noguchi, Emiko
A1  - Grimbacher, Bodo
A1  - Eibel, Hermann
T1  - Sphingosine-1-phosphate receptors control B-cell migration through signaling components associated with primary immunodeficiencies, chronic lymphocytic leukemia, and multiple sclerosis
JF  - The journal of allergy and clinical immunology
N2  - Background: Five different G protein-coupled sphingosine-1-phosphate (S1P) receptors (S1P1-S1P5) regulate a variety of physiologic and pathophysiologic processes, including lymphocyte circulation, multiple sclerosis (MS), and cancer. Although B-lymphocyte circulation plays an important role in these processes and is essential for normal immune responses, little is known about S1P receptors in human B cells.
 Objective: To explore their function and signaling, we studied B-cell lines and primary B cells from control subjects, patients with leukemia, patients with S1P receptor inhibitor-treated MS, and patients with primary immunodeficiencies.
 Methods: S1P receptor expression was analyzed by using multicolor immunofluorescence microscopy and quantitative PCR. Transwell assays were used to study cell migration. S1P receptor internalization was visualized by means of time-lapse imaging with fluorescent S1P receptor fusion proteins expressed by using lentiviral gene transfer. B-lymphocyte subsets were characterized by means of flow cytometry and immunofluorescence microscopy.
 Results: Showing that different B-cell populations express different combinations of S1P receptors, we found that S1P1 promotes migration, whereas S1P4 modulates and S1P2 inhibits S1P1 signals. Expression of CD69 in activated B lymphocytes and B cells from patients with chronic lymphocytic leukemia inhibited S1P-induced migration. Studying B-cell lines, normal B lymphocytes, and B cells from patients with primary immunodeficiencies, we identified Bruton tyrosine kinase, beta-arrestin 2, LPS-responsive beige-like anchor protein, dedicator of cytokinesis 8, and Wiskott-Aldrich syndrome protein as critical signaling components downstream of S1P1.
 Conclusion: Thus S1P receptor signaling regulates human B-cell circulation and might be a factor contributing to the pathology of MS, chronic lymphocytic leukemia, and primary immunodeficiencies.
KW  - Sphingosine-1-phosphate
KW  - B cells
KW  - migration
KW  - autoimmunity
KW  - circulation
KW  - fingolimod
KW  - FTY720
KW  - primary immunodeficiencies
Y1  - 2014
U6  - https://doi.org/10.1016/j.jaci.2014.01.037
SN  - 0091-6749
SN  - 1097-6825
VL  - 134
IS  - 2
SP  - 420
EP  - +
PB  - Elsevier
CY  - New York
ER  -