RFI Statistical Distribution and Missed Detection in Aquarius Radiometer Measurements

Aquarius is an microwave active/passive sensor whose main goal is to globally estimate sea surface salinity from space. Two instruments, a radar scatterometer and a radiometer, operate at L-band observing the same surface footprint almost simultaneously. The sensitivity to sea surface salinity (SSS) is given by the radiometer, while the scatterometer measurements provide a correction for sea surface roughness. Although the primary objective is the measurement of SSS, the instrument combination operates continuously, acquiring data over land and sea ice as well. Radio Frequency Interference (RFI) can occur in both the radiometer and the scatterometer bands of operation, and for this reason detection and mitigation of RFI was included in the data processing of both active and passive instruments. This paper will focus on the RFI processing for the Aquarius radiometer only and provide an update on the efforts to reduce the amount of missed RFI detection

Aquarius Active-Passive RFI Environment at L-Band

Active/Passive instrument combinations (i.e., radiometer and radar) are being developed at L-band for remote sensing of sea surface salinity and soil moisture. Aquarius is already in orbit and SMAP is planned for launch in the Fall of 2014. Aquarius has provided for the first time a simultaneous look at the Radio Frequency Interference (RFI) environment from space for both active and passive instruments. The RFI environment for the radiometer observations is now reasonably well known and examples from Aquarius are presented in this manuscript that show that RFI is an important consideration for the scatterometer as well. In particular, extensive areas of the USA, Europe and Asia exhibit strong RFI in both the radiometer band at 1.41 GHz and in the band at 1.26 GHz employed by the Aquarius scatterometer. Furthermore, in areas such as the USA, where RFI at 1.4 GHz is relatively well controlled, RFI in the scatterometer band maybe the limiting consideration for the operation of combination active/passive instruments

Localization of L-Band RFI Sources from SMAP Data

RFI (Radio-Frequency Interference) in the 1400-1427 MHz band degrades the quality of measurements made by satellite missions such as SMAP (Soil Moisture Active/Passive), Aquarius and SMOS (Soil Moisture and Ocean Salinity). A technique is presented here to estimate the location on the ground of RFI sources using SMAP measurements. The results of this technique have been validated against data derived by other means

L-Band RFI in Japan

In recent years, three instruments have been launched into orbit with the aim of producing global maps of sea surface salinity and soil moisture using the 1400-1427 MHz band: SMOS, Aquarius and SMAP. Although this frequency band is allocated to passive measurements only, RFI (Radio-Frequency Interference) is present in the data of all three missions. On a global scale, the three sensors have observed approximately the same distribution of RFI. Japan is an important exception that has implications for the design of RFI detection algorithms. RFI in Japan is caused by a large number of emitters belonging to the same system (TV receivers) and for this reason some traditional RFI detection strategies detect little to no RFI over Japan. The study of this case has led to an improvement of the approach to detect RFI in Aquarius data

Molecular phylogeny of two lineages of Leuciscinae cyprinids (Telestes and Scardinius) from the peri-Mediterranean area based on cytochrome b data.

We examined phylogenetic relationships in two lineages of Leuciscinae cyprinid fishes based on the sequence data of the complete mitochondrial DNA region coding for the cytochrome b gene (1140 bp). Telestes includes obligate riverine, moderately cold wateradapted species whereas Scardinius comprises warm-adapted species living in lowland lakes and still waters of rivers and streams. We also analysed selected representatives of Leuciscus and Phoxinellus because the taxonomic status of some species belonging to these genera is dubious and they could be placed in the genus Telestes. The study includes 18 species, 43 populations, and 111 individuals from 9 of the 14 peri-Mediterranean ichthyogeographic districts. Clades recovered from the phylogenetic analyses do not support previous taxonomic assumptions based on morphology. Telestes, Leuciscus, and Phoxinellus do not form monophyletic assemblages; phylogenetic analyses suggest that L. polylepis, L. turskyi, P. croaticus, and P. metohiensis should be included in Telestes. Similarly, populations of Scardinius erythrophthalmus do not cluster together and the endangered S. scardafa, endemic to central Italy and surviving in a single locality, is nested within them. The radiations of Telestes and Scardinius occurred in different time periods. A major diversification of Telestes is consistent with a sea dispersal during the freshwater Messinian ‘‘Lago Mare’’ phase of the Mediterranean Sea. Cladogenetic events within Scardinius are likely related to the extension and confluence of river drainages in lowlands following multiple lowering of the sea level during the Quaternary glaciations

Aquarius Overview and Up Date

Aquarius is an L-band instrument designed to map the surface salinity field of the global oceans. It consists of three L-band (1.41 GHz) radiometers and an L-band (1.26 GHz) scatterometer. The radiometers are the primary instruments for measuring salinity and the scatterometer provides a correction for surface roughness. Aquarius was launched in June 2011 and has been mapping the surface salinity field since it was turned on in August. In addition, Aquarius is now producing maps of radio frequency interference (RFI), Faraday rotation and soil moisture

Recent Advances in SMAP RFI Processing

The measurements made by the Soil Moisture Active/Passive (SMAP) mission are affected by the presence of Radio Frequency Interference (RFI) in the protected 1400-1427 MHz band. In SMAP data processing, the main protection against RFI is a sophisticated RFI detection algorithm which flags sub-samples in time and frequency that are contaminated by RFI and removes them before estimating the brightness temperature. This contribution presents two additional approaches that have been developed to address the RFI concern in SMAP. The first consists in locating sources of RFI; once located, it becomes possible to report RFI sources to spectrum management authorities, which can lead to less RFI being experienced by SMAP in the future. The second is a new RFI detection method that is based on detecting outliers in the spatial distribution of measured antenna temperatures

Aquarius Radiometer Status

Aquarius was launched on June 10, 2011 as part of the Aquarius/SAC-D observatory and the instrument has been operating continuously since being turned on in August of the same year. The initial map of sea surface salinity was released one month later (September) and the quality of the retrieval has continuously improved since then. The Aquarius radiometers include several special features such as measurement of the third Stokes parameter, fast sampling, and careful thermal control, and a combined passive/active instrument. Aquarius is working well and in addition to helping measure salinity, the radiometer special features are generating new results

Risk of hospitalization for heart failure in patients with type 2 diabetes newly treated with DPP-4 inhibitors or other oral glucose-lowering medications: A retrospective registry study on 127,555 patients from the Nationwide OsMed Health-DB Database

Aims Oral glucose-lowering medications are associated with excess risk of heart failure (HF). Given the absence of comparative data among drug classes, we performed a retrospective study in 32 Health Services of 16 Italian regions accounting for a population of 18 million individuals, to assess the association between HF risk and use of sulphonylureas, DPP-4i, and glitazones. Methods and results We extracted data on patients with type 2 diabetes who initiated treatment with DPP-4i, thiazolidinediones, or sulphonylureas alone or in combination with metformin during an accrual time of 2 years. The endpoint was hospitalization for HF (HHF) occurring after the first 6 months of therapy, and the observation was extended for up to 4 years. A total of 127 555 patients were included, of whom 14.3% were on DPP-4i, 72.5% on sulphonylurea, 13.2% on thiazolidinediones, with average 70.7% being on metformin as combination therapy. Patients in the three groups differed significantly for baseline characteristics: age, sex, Charlson index, concurrent medications, and previous cardiovascular events. During an average 2.6-year follow-up, after adjusting for measured confounders, use of DPP-4i was associated with a reduced risk of HHF compared with sulphonylureas [hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.62-0.97; P = 0.026]. After propensity matching, the analysis was restricted to 39 465 patients, and the use of DPP-4i was still associated with a lower risk of HHF (HR 0.70; 95% CI 0.52-0.94; P = 0.018). Conclusion In a very large observational study, the use of DPP-4i was associated with a reduced risk of HHF when compared with sulphonylureas

Metabolic disorders across hepatocellular carcinoma in Italy

BACKGROUND: Metabolic disorders are well-known risk factors for HCC. Conversely, their impact on the natural history of HCC is not established. This study aimed at evaluating the impact of metabolic disorders on clinical features, treatment and survival of HCC patients regardless of its aetiology. METHODS: We analysed the ITA.LI.CA database regarding 839 HCC patients prospectively collected. The following metabolic features were analysed: BMI, diabetes, arterial hypertension, hypercholesterolaemia and hypertriglyceridaemia. According to these features, patients were divided into 3 groups: 0-1, 2 and 3-5 metabolic features. RESULTS: As compared with patients with 0-1 metabolic features, patients with 3-5 features showed lower percentage of HCC diagnosis on surveillance (P = .021), larger tumours (P = .038), better liver function (higher percentage of Child-Pugh class A [P = .007] and MELD < 10 [P = .003]), higher percentage of metastasis (P = .024) and lower percentage of portal vein thrombosis (P = .010). The BCLC stage and treatment options were similar among the 3 groups, with the exception of a less frequent access to loco-regional therapies for BCLC stage B patients with 3-5 features (P = .012). Overall survival and survival according to BCLC stage and/or treatment did not significantly differ among the 3 groups. Only using a probabilistic sensitivity analysis, diabetic patients showed a lower survival (P = .046). MELD score, HCC morphology, nodule size, BCLC stage, portal vein thrombosis and metastasis were independent predictors of lead-time adjusted survival. CONCLUSIONS: Our "real world" study suggests that metabolic disorders shape the clinical presentation of HCC but do not seem to play a major role in setting patient survival.Background: Metabolic disorders are well-known risk factors for HCC. Conversely, their impact on the natural history of HCC is not established. This study aimed at evaluating the impact of metabolic disorders on clinical features, treatment and survival of HCC patients regardless of its aetiology. Methods: We analysed the ITA.LI.CA database regarding 839 HCC patients prospectively collected. The following metabolic features were analysed: BMI, diabetes, arterial hypertension, hypercholesterolaemia and hypertriglyceridaemia. According to these features, patients were divided into 3 groups: 0-1, 2 and 3-5 metabolic features. Results: As compared with patients with 0-1 metabolic features, patients with 3-5 features showed lower percentage of HCC diagnosis on surveillance (P =.021), larger tumours (P =.038), better liver function (higher percentage of Child-Pugh class A [P =.007] and MELD < 10 [P =.003]), higher percentage of metastasis (P =.024) and lower percentage of portal vein thrombosis (P =.010). The BCLC stage and treatment options were similar among the 3 groups, with the exception of a less frequent access to loco-regional therapies for BCLC stage B patients with 3-5 features (P =.012). Overall survival and survival according to BCLC stage and/or treatment did not significantly differ among the 3 groups. Only using a probabilistic sensitivity analysis, diabetic patients showed a lower survival (P =.046). MELD score, HCC morphology, nodule size, BCLC stage, portal vein thrombosis and metastasis were independent predictors of lead-time adjusted survival. Conclusions: Our \u201creal world\u201d study suggests that metabolic disorders shape the clinical presentation of HCC but do not seem to play a major role in setting patient survival