The Global Precipitation Measurement (GPM) Mission: Overview and U.S. Status

The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. Building upon the success of the U.S.-Japan Tropical Rainfall Measuring Mission (TRMM), the National Aeronautics and Space Administration (NASA) of the United States and the Japan Aerospace and Exploration Agency (JAXA) will deploy in 2013 a GPM "Core" satellite carrying a KulKa-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Imager (GMI) to establish a new reference standard for precipitation measurements from space. The combined active/passive sensor measurements will also be used to provide common database for precipitation retrievals from constellation sensors. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer- 2 (AMSR-2) on the GCOM-Wl satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha-Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites, and (8) a microwave imager under planning for the Defense Weather Satellite System (DWSS)

Effect of Dupilumab on Sleep Apnea Severity in Patients With Chronic Rhinosinusitis

Patients with chronic rhinosinusitis (CRS) report improved sleep quality after dupilumab, an anti IL4/13 therapy. Concurrent CRS and obstructive sleep apnea (OSA) cases are not rare, and CRS seemingly raises nasal resistance. Thus, we hypothesized that improved sleep quality by dupilumab therapy in CRS patients might be due to lowered nasal resistance and subsequent improvement of unrecognized comorbid OSA. Patients with concurrent CRS and OSA were recruited. Nasal resistance was measured invasively with transnasal pressure and flow data collected during normal respiration in the supine position. Results from the first five participants did not support our hypothesis. Subjective and objective measures for CRS and nasal resistance values were improved with dupilumab therapy in CRS patients with nasal polyps. However, apnea severity and sleep-related subjective parameters did not change. In the patients with CRS without nasal polyps, no significant changes in either CRS or OSA-related measures were observed

Multiethnic Meta-Analysis Identifies RAI1 as a Possible Obstructive Sleep Apnea-related Quantitative Trait Locus in Men.

Obstructive sleep apnea (OSA) is a common heritable disorder displaying marked sexual dimorphism in disease prevalence and progression. Previous genetic association studies have identified a few genetic loci associated with OSA and related quantitative traits, but they have only focused on single ethnic groups, and a large proportion of the heritability remains unexplained. The apnea-hypopnea index (AHI) is a commonly used quantitative measure characterizing OSA severity. Because OSA differs by sex, and the pathophysiology of obstructive events differ in rapid eye movement (REM) and non-REM (NREM) sleep, we hypothesized that additional genetic association signals would be identified by analyzing the NREM/REM-specific AHI and by conducting sex-specific analyses in multiethnic samples. We performed genome-wide association tests for up to 19,733 participants of African, Asian, European, and Hispanic/Latino American ancestry in 7 studies. We identified rs12936587 on chromosome 17 as a possible quantitative trait locus for NREM AHI in men (N = 6,737; P = 1.7 × 10 <sup>-8</sup> ) but not in women (P = 0.77). The association with NREM AHI was replicated in a physiological research study (N = 67; P = 0.047). This locus overlapping the RAI1 gene and encompassing genes PEMT1, SREBF1, and RASD1 was previously reported to be associated with coronary artery disease, lipid metabolism, and implicated in Potocki-Lupski syndrome and Smith-Magenis syndrome, which are characterized by abnormal sleep phenotypes. We also identified gene-by-sex interactions in suggestive association regions, suggesting that genetic variants for AHI appear to vary by sex, consistent with the clinical observations of strong sexual dimorphism

The Global Precipitation Measurement (GPM) Mission: Overview and Status

The Global Precipitation Measurement (GPM) Mission is an international satellite mission to unify and advance global precipitation measurements from a constellation of dedicated and operational microwave sensors. The GPM concept centers on the deployment of a Core SpacecraR in a non-Sun-synchronous orbit at 65 deg. inclination carrying a dual-frequency precipitation radar (DPR) and a multi-frequency passive microwave radiometer (GMI) with high-frequency capabilities to serve as a precipitation physics observatory and calibration standard for the constellation radiometers. The baseline GPM constellation is envisioned to comprise conical-scanning microwave imagers (e.g., GMI, SSMIS, AMSR, MIS, MADRAS, GPM-Brazil) augmented with cross-track microwave temperaturethumidity sounders (e.g., MHS, ATMS) over land. In addition to the Core Satellite, the GPM Mission will contribute a second GMI to be flown in a low-inclination (approximately 40 deg.) non-Sun-synchronous orbit to improve near-realtime monitoring of hurricanes. GPM is a science mission with integrated applications goals aimed at (1) advancing the knowledge of the global watertenergy cycle variability and freshwater availability and (2) improving weather, climate, and hydrological prediction capabilities through more accurate and frequent measurements of global precipitation. The GPM Mission is currently a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), with opportunities for additional partners in satellite constellation and ground validation activities. Within the framework of the inter-governmental Group ob Earth Observations (GEO) and Global Earth Observation System of Systems (GEOSS), GPM has been identified as a cornerstone for the Precipitation Constellation (PC) being developed under the auspices of Committee of Earth Observation Satellites (CEOS). The GPM Core Observatory is scheduled for launch in 2013, followed by the launch of the GPM Low-Inclination Observatory in 2014. An overview of the GPM mission status, instrument capabilities, ground validation plans, and anticipated scientific and societal benefits will be presented

Desipramine improves upper airway collapsibility and reduces OSA severity in patients with minimal muscle compensation

We recently demonstrated that desipramine reduces the sleep-related loss of upper airway dilator muscle activity and reduces pharyngeal collapsibility in healthy humans without obstructive sleep apnoea (OSA). The aim of the present physiological study was to determine the effects of desipramine on upper airway collapsibility and apnoea-hypopnea index (AHI) in OSA patients. A placebo-controlled, double-blind, randomised crossover trial in 14 OSA patients was performed. Participants received treatment or placebo in randomised order before sleep. Pharyngeal collapsibility (critical collapsing pressure of the upper airway (Pcrit)) and ventilation under both passive (V′0,passive) and active (V′0,active) upper airway muscle conditions were evaluated with continuous positive airway pressure (CPAP) manipulation. AHI was quantified off CPAP. Desipramine reduced active Pcrit (median (interquartile range) -5.2 (4.3) cmH2O on desipramine versus -1.9 (2.7) cmH2O on placebo; p=0.049) but not passive Pcrit (-2.2 (3.4) versus -0.7 (2.1) cmH2O; p=0.135). A greater reduction in AHI occurred in those with minimal muscle compensation (defined as V′0,active-V′0, passive) on placebo (r=0.71, p=0.009). The reduction in AHI was driven by the improvement in muscle compensation (r=0.72, p=0.009). In OSA patients, noradrenergic stimulation with desipramine improves pharyngeal collapsibility and may be an effective treatment in patients with minimal upper airway muscle compensation