206 research outputs found
SMOS-NEXT: A New Concept for Soil Moisture Retrieval from Passive Interferometric Observations
This book is a collection of 19 articles which reflect the courses given at the CollĂšge de France/Summer school âReconstruction d'images â Applications astrophysiquesâ held in Nice and FrĂ©jus, France, from June 18 to 22, 2012. The articles presented in this volume address emerging concepts and methods that are useful in the complex process of improving our knowledge of the celestial objects, including Earth
Global-scale comparison of passive (SMOS) and active (ASCAT) satellite based microwave soil moisture retrievals with soil moisture simulations (MERRA-Land)
AbstractGlobal surface soil moisture (SSM) datasets are being produced based on active and passive microwave satellite observations and simulations from land surface models (LSM). This study investigates the consistency of two global satellite-based SSM datasets based on microwave remote sensing observations from the passive Soil Moisture and Ocean Salinity (SMOS; SMOSL3 version 2.5) and the active Advanced Scatterometer (ASCAT; version TU-Wien-WARP 5.5) with respect to LSM SSM from the MERRA-Land data product. The relationship between the global-scale SSM products was studied during the 2010â2012 period using (1) a time series statistics (considering both original SSM data and anomalies), (2) a spaceâtime analysis using Hovmöller diagrams, and (3) a triple collocation error model. The SMOSL3 and ASCAT retrievals are consistent with the temporal dynamics of modeled SSM (correlation R>0.70 for original SSM) in the transition zones between wet and dry climates, including the Sahel, the Indian subcontinent, the Great Plains of North America, eastern Australia, and south-eastern Brazil. Over relatively dense vegetation covers, a better consistency with MERRA-Land was obtained with ASCAT than with SMOSL3. However, it was found that ASCAT retrievals exhibit negative correlation versus MERRA-Land in some arid regions (e.g., the Sahara and the Arabian Peninsula). In terms of anomalies, SMOSL3 better captures the short term SSM variability of the reference dataset (MERRA-Land) than ASCAT over regions with limited radio frequency interference (RFI) effects (e.g., North America, South America, and Australia). The seasonal and latitudinal variations of SSM are relatively similar for the three products, although the MERRA-Land SSM values are generally higher and their seasonal amplitude is much lower than for SMOSL3 and ASCAT. Both SMOSL3 and ASCAT have relatively comparable triple collocation errors with similar spatial error patterns: (i) lowest errors in arid regions (e.g., Sahara and Arabian Peninsula), due to the very low natural variability of soil moisture in these areas, and Central America, and (ii) highest errors over most of the vegetated regions (e.g., northern Australia, India, central Asia, and South America). However, the ASCAT SSM product is prone to larger random errors in some regions (e.g., north-western Africa, Iran, and southern South Africa). Vegetation density was found to be a key factor to interpret the consistency with MERRA-Land between the two remotely sensed products (SMOSL3 and ASCAT) which provides complementary information on SSM. This study shows that both SMOS and ASCAT have thus a potential for data fusion into long-term data records
Remote Sensing Studies of Urban Canopies: 3D Radiative Transfer Modeling
Need for better understanding and more accurate estimation of radiative fluxes in urban environments, specifically urban surface albedo and exitance, motivates development of new remote sensing and threeâdimensional (3D) radiative transfer (RT) modeling methods. The discrete anisotropic radiative transfer (DART) model, one of the most comprehensive physically based 3D models simulating Earth/atmosphere radiation interactions, was used in combination with satellite data (e.g., Landsatâ8 observations) to better parameterize the radiative budget components of cities, such as Basel in Switzerland. After presenting DART and its recent RT modeling functions, we present a methodological concept for estimating urban fluxes using any satellite image data
Leptonic Decays of Heavy Quarks on the Lattice
The status of lattice calculations of heavy-light decay constants and of the
parameter is reviewed. After describing the lattice approach to heavy
quark systems, the main results are discussed, with special emphasis on the
systematic errors in present lattice calculations. A detailed analysis of the
continuum limit for decay constants is performed. The implications of lattice
results on studies of CP violation in the Standard Model are discussed.Comment: Invited review to be published in Int. J. Mod. Phys. A, 63 pages,
LaTeX, ijmpa1.sty (included), 8 postscript figure
Hypocone Reduction and Carabelliâs Traits in Contemporary Jordanians and the Association between Carabelliâs Trait and the Dimensions of the Maxillary First Permanent Molar
The objective of this study is to determine the prevalence of expression and bilateralism of two dental morphological
traits in contemporary Jordanians: The hypocone reduction trait on the maxillary second permanent molar and Carabelliâs
trait on maxillary permanent first and second molars. Furthermore, inter-trait correlation and the relationship
of Carabelliâs traits with upper first molar dimensions were investigated. Three hundred subjects of school children at
their 10th grade and of an average age of 15.5±0.4 years were involved. Alginate impressions for the maxillary arch were
taken, dental casts were reproduced. The selected accurate casts were of 132 male- and 155 female-students. The frequencies
of hypocone reduction trait on the maxillary second molar and Carabelliâs trait on the maxillary molars were examined.
Buccolingual and mesiodistal diameters of the maxillary first molar were measured and recorded. Paired Sample t
test and Nonparametric Correlation analysis were used for data analysis. Hypocone reduction trait on the maxillary second
molar was found in 29.8 % of the examined students. Positive forms of Carabelliâs trait on first and second molars
were observed in 65.0 % and 3.8 %, respectively. Nonparametric correlation analysis revealed positive association between
Carabelliâs trait on first molar and hypocone reduction trait on the maxillary second molar. The presence of Carabelliâs
trait on first molar was strongly associated with the increase of buccolingual, but not the mesiodistal, diameter.
Bilateralism was found highly significant in the tested traits and both genders (p<0.001). This finding might be a sign
of relatively low environmental stresses in the living Jordanian population and/or great ability of its individuals to
buffer the adverse effects of such stresses
Agronomic performance of annual self-reseeding legumes and their self-establishment potential in the Apulia region of Italy
Abstract The agronomic performance, biological nitrogen fixation (BNF
Typhoid ulcer causing life-threatening bleeding from Dieulafoy's lesion of the ileum in a seven-year-old child: a case report
<p>Abstract</p> <p>Introduction</p> <p>We describe a case of rare complication of typhoid fever in a seven-year-old child and review the literature with regard to other rare causes of bleeding per rectum. Dieulafoy's lesion is an uncommon but important cause of recurrent gastrointestinal bleeding. Dieulafoy's lesion located extragastrically is rare. We report a case of typhoid ulcer with Dieulafoy's lesion of the ileum causing severe life-threatening bleeding and discuss the management of this extremely uncommon entity.</p> <p>Case presentation</p> <p>As a complication of typhoid fever, a seven-year-old Kurdish girl from Northern Iraq developed massive fresh bleeding per rectum. During colonoscopy and laparotomy, she was discovered to have multiple bleeding ulcers within the Dieulafoy's lesion in the terminal ileum and ileocecal region.</p> <p>Conclusion</p> <p>Although there is no practical way of predicting the occurrence of such rare complications, we emphasize in this case report the wide array of pathologies that can result from typhoid fever.</p
Mesiodistal root angulation of permanent teeth in children with mixed dentition and normal occlusion
A New Model for Raf Kinase Inhibitory Protein Induced Chemotherapeutic Resistance
Therapeutic resistance remains the most challenging aspect of treating cancer. Raf kinase inhibitory protein (RKIP) emerged as a molecule capable of sensitizing cancerous cells to radio- and chemotherapy. Moreover, this small evolutionary conserved molecule, endows significant resistance to cancer therapy when its expression is reduced or lost. RKIP has been shown to inhibit the Raf-MEK-ERK, NFÎșB, GRK and activate the GSK3ÎČ signaling pathways. Inhibition of Raf-MEK-ERK and NFÎșB remains the most prominent pathways implicated in the sensitization of cells to therapeutic drugs. Our purpose was to identify a possible link between RKIP-KEAP 1-NRF2 and drug resistance. To that end, RKIP-KEAP 1 association was tested in human colorectal cancer tissues using immunohistochemistry. RKIP miRNA silencing and its inducible overexpression were employed in HEK-293 immortalized cells, HT29 and HCT116 colon cancer cell lines to further investigate our aim. We show that RKIP enhanced Kelch-like ECH-associated protein1 (KEAP 1) stability in colorectal cancer tissues and HT29 CRC cell line. RKIP silencing in immortalized HEK-293 cells (termed HEK-499) correlated significantly with KEAP 1 protein degradation and subsequent NRF2 addiction in these cells. Moreover, RKIP depletion in HEK-499, compared to control cells, bestowed resistance to supra physiological levels of H2O2 and Cisplatin possibly by upregulating NF-E2-related nuclear factor 2 (NRF2) responsive genes. Similarly, we observed a direct correlation between the extent of apoptosis, after treatment with Adriamycin, and the expression levels of RKIP/KEAP 1 in HT29 but not in HCT116 CRC cells. Our data illuminate, for the first time, the NRF2-KEAP 1 pathway as a possible target for personalized therapeutic intervention in RKIP depleted cancers
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