5,838 research outputs found
Historic thermal calibration of landsat 5 TM through an improved physics based approach
This investigation is motivated by the current need for a detailed post launch calibration of the Thematic Mapper (TM) thermal band (Band 6), aboard NASA’s Landsat 5 spacecraft. The historical calibration spans the period from 1984 to 2007. It is through fusion of environmental data sources (i.e. buoy observations, surface observations, and radiosonde observations) that a vicarious calibration approach will be implemented to construct the complete calibration record of the Landsat 5 TM thermal band. The vicarious calibration process takes advantage of the long standing National Data Buoy Center (NDBC) moored buoy fleet to acquire historic ground truth measurements needed over the lifetime of Landsat 5. These measurements are propagated to the sensor through the use of physics based models to establish a predicted at sensor radiance. Through comparison of the predicted at sensor radiance and the actual sensor observed radiance, a calibration metric is established. Results indicate the Landsat 5 TM thermal band, originally planned for a 3 year mission, has fluctuated only slightly ( 1 K) over the 24+ years in orbit. The calibration curve developed in this study is consistent with previous results from campaigns preformed in 1985 and post 1999. The data indicated that the sensor exhibited a clear gain issue (i.e. over estimates low radiance targets and under estimates high radiance targets) found to be approximately consistent over time. Additionally, an event occurring either prior to or during 1999, caused a discernible fluctuation in sensor performance (i.e. dominant cold bias) for all data post 1999. It is the recommendation of this vicarious calibration I II campaign that a linear (Dual: slope & intercept) correction be applied to the Landsat 5 data archive. As a result of the correction, the Landsat 5 TM Band 6 is radiometrically calibrated to within ±0.488 K, in reference to a 300 K blackbody. This result was verified through an extensive error propagation analysis, which found the proposed methodology to have an expected error of 0.454 K. The proposed methodology was also verified by a comparison study to the traditional approach (i.e. non buoy derived ground truth) using the closely monitored and trusted Landsat 7 data calibrated using the traditional approach. The comparison found the two methods were not statistically different, which offered the confidence that this methodology could be applied successfully over the domain of this study. This comparison not only validates the calibration record of Landsat 5, but also demonstrates the utility of the method in future efforts. This work has demonstrated that a successful historical vicarious calibration campaign can be conducted using exclusively free and easily accessible data. It has been established that the proposed methodology can be implemented to achieve a high level of radiometric integrity, which includes both historic and future efforts, in the calibration of remote thermal infrared systems
Squeezed Fermions at Relativistic Heavy Ion Colliders
Large back-to-back correlations of observable fermion -- anti-fermion pairs
are predicted to appear, if the mass of the fermions is modified in a
thermalized medium. The back-to-back correlations of protons and anti-protons
are experimentally observable in ultra-relativistic heavy ion collisions,
similarly to the Andreev reflection of electrons off the boundary of a
superconductor. While quantum statistics suppresses the probability of
observing pairs of fermions with nearby momenta, the fermionic back-to-back
correlations are positive and of similar strength to bosonic back-to-back
correlations.Comment: LaTeX, ReVTeX 12 pages, uses epsf.sty, 2 eps figures, improved
presentatio
Back-to-Back Correlations for Finite Expanding Fireballs
Back-to-Back Correlations of particle-antiparticle pairs are related to the
in-medium mass-modification and squeezing of the quanta involved. They are
predicted to appear when hot and dense hadronic matter is formed in high energy
nucleus-nucleus collisions. The survival and magnitude of the Back-to-Back
Correlations of boson-antiboson pairs generated by in-medium mass modifications
are studied here in the case of a thermalized, finite-sized, spherically
symmetric expanding medium. We show that the BBC signal indeed survives the
finite-time emission, as well as the expansion and flow effects, with
sufficient intensity to be observed at RHIC.Comment: 24 pages, 4 figure
A First Step for the Molecular Characterization of Neurological Involvement of Behçet Syndrome: an Italian Pivotal Study
Behçet syndrome (BS) is a vasculitis characterized by several clinical manifestations including the rare neurological involvement (neuro-BS, NBS). The aim of our pivotal study was to investigate the mutational status of several inflammation-related genes in a cohort of Italian patients with and without the neurological involvement (20 NBS vs 40 no-NBS patients). The preliminary in silico single nucleotide polymorphism (SNP) selection and primer design were performed by NCBI Primer-Blast tool. Genomic DNA was isolated and amplified using PCR. PCR amplicons were sequenced and bioinformatically analysed. Twelve tagSNPs were selected and genotyped: ERAP1 rs30187, rs17482078, and rs27044; IL10 rs1800872 and rs1518111, IL12A rs17810546, IL23R rs17375018, IL23R-IL12RB2 rs924080, STAT4 rs7572482, CCR1 rs7616215, KLRC4 rs2617170, and UBAC2 rs3825427. ERAP1 and IL23R SNPs showed statistically significant higher frequencies in NBS group than no-NBS. ERAP1 rs30187 AA was more common in no-NBS patients (20.0% NBS vs 47.5% no-NBS; p < 0.05), while rs17482078 GA frequency was higher in NBS patients (55.0% NBS vs 22.5% no-NBS; p < 0.05, OR: 4.21). IL23R rs17375018 GG was more frequent in NBS group (65.0% NBS vs 40.0% no-NBS; p < 0.05), according to a previous finding. No other statistically significant differences were found. In conclusion, ERAP1 and IL23R SNPs were found associated with neurological involvement of BS. Additional and larger analyses were required to verify our preliminary findings
Determination of Ganciclovir in Plasma of Newborns with Congenital CMV Infection
Infections caused by human cytomegalovirus are important causes of fetal and neonatal morbidity and mortality. Ganciclovir ([(9-(1,3-dihydroxy-2- propoxymethyl) guanine, GCV) is a synthetic acyclic nucleoside which has shown activity against Cytomegalovirus. GCV treatment has been associated with serious toxic hematological effects such
as neutropenia and leukopenia, thus drug monitoring is needed, especially in the case of
newborns. The aim of the work is to develop and validate an HPLC method for the quantification of GCV in plasm
In search of a universal and objective method to assess facial aging: The new face objective photo-numerical assessment scale
Most patients who undergo cosmetic rejuvenation treatment hope to appear younger and healthier. Although a number of scales have been put forward to assess facial aging, to date none has focused on predicting patients’ age. The purpose of our study was to validate a more complete version of the face - Objective assessment scale previously developed by the authors. Since patients with a photo-damaged skin can look older than others we created a new sub-scale: the facial photo-aging scale, in order to provide a more comprehensive method for the overall assessment of facial aging. The Rasch model was used as part of the validation process. We assigned a score to each patient based on the scales we have developed. The correlation between a patient's actual age and the obtained scores was analyzed; we also analyzed the inter-rater reliability and test-retest reliability. All the scales exceeded criteria for acceptability, reliability and validity. The facial aging scale we have developed may prove to be a valuable tool to assess patients before and after facial rejuvenation treatment or surgery, as well as for clinical research in the field of facial skin regeneration
Triple SILAC identified progestin-independent and dependent PRA and PRB interacting partners in breast cancer
Progesterone receptor (PR) isoforms, PRA and PRB, act in a progesterone-independent and dependent manner to differentially modulate the biology of breast cancer cells. Here we show that the differences in PRA and PRB structure facilitate the binding of common and distinct protein interacting partners affecting the downstream signaling events of each PR-isoform. Tet-inducible HA-tagged PRA or HA-tagged PRB constructs were expressed in T47DC42 (PR/ER negative) breast cancer cells. Affinity purification coupled with stable isotope labeling of amino acids in cell culture (SILAC) mass spectrometry technique was performed to comprehensively study PRA and PRB interacting partners in both unliganded and liganded conditions. To validate our findings, we applied both forward and reverse SILAC conditions to effectively minimize experimental errors. These datasets will be useful in investigating PRA- and PRB-specific molecular mechanisms and as a database for subsequent experiments to identify novel PRA and PRB interacting proteins that differentially mediated different biological functions in breast cancer
Proposal of a Noninvasive Method to Reduce Injection-Related Bruising in Aesthetic Medicine: Transillumination
Background: Hyaluronic acid (HA) injections involve a risk of vascular complications. Transillumination (TL) is a noninvasive technique that appears to allow preliminary detection of superficial vascular structures of the face to avoid intravascular HA injection. The purpose of our study was to test the efficacy of TL in terms of its sensitivity to locate vessels in the areas undergoing treatment and to reduce post-injection vascular complications. Material and Methods: We conducted a prospective study enrolling 72 patients who consulted for HA injections to treat facial wrinkles. We used TL on one side of the face to obtain a vascular mapping of the face. The area undergoing testing was randomized for the TL technique. The primary study endpoint was sensitivity for identifying subcutaneous veins and the differences in complication rates between the side of the face where TL was used to guide the injection and the side of the face where no vascular exploration method was used. Results: TL sensitivity for locating the superficial temporal vein was 100%, 91% for the supratrochlear, supraorbital and infraorbital veins, and 95% for the dorsal nasal veins (p < 0.01). The complication rate was higher on the side of the face where no vascular exploration method was used (22.2% vs 2.7%; p = 0.010046). Conclusions: Our preliminary findings validate our hypothesis concerning the advantage of using TL to identify superficial veins before performing injections. This method is simple and affordable, and the learning curve is small. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266
- …