Millimeter and sub-millimeter wave radiometers for atmospheric remote sensing from CubeSat platforms

2018 Fall.Includes bibliographical references.To view the abstract, please see the full text of the document

Microwave Radiometer Calibration Using Deep Learning With Reduced Reference Information and 2-D Spectral Features

The accuracy of geophysical retrievals from radiometers relies on calibration quality, encompassing both absolute radiometric accuracy and spectral consistency. Radiometers have employed various calibration techniques, including external targets, vicarious sources, and internal calibrators like noise diodes or matched reference loads. Calibration techniques face challenges like frequency dependence, instrumental effects, environmental influences, drift, aging, and radio frequency interference. Recent hardware advancements enable radiometers to collect raw samples containing both temporal and spectral information. Leveraging advanced modeling techniques like deep learning (DL) enables detecting subtle correlations, non-linear dependencies, and higher-order interactions within the data extracting valuable information that may have been challenging with conventional methods. This study utilizes NASA's Soil Moisture Active Passive (SMAP) satellite's level 1A and level 1B data products to develop a DL-based radiometer calibrator to estimate antenna temperature. Spectrograms of second raw moments equivalent to power carrying the 2-D spectral features serve as primary input in a supervised convolutional neural network-based architecture. DL-based calibrator has demonstrated high correlation and low root mean square error when incorporating spectral information from both reference and noise diodes and when not considering this information. Findings suggest that the ancillary features such as internal thermistor temperature and loss elements exhibit sufficient accuracy in estimating antenna temperature to compensate for variations in receiver noise temperature and short-term gain fluctuations in the absence of the reference load and noise diode power. The proposed calibration technique with reduced reference information might enable radiometers for a higher number of antenna scene observations within a footprint

Adverse Effect of Noise on Voice Perturbation Estimates: A Comparison of Three Voice Analysis Programs

WOS: 000291330700022Objective: The aim of this study is to investigate the influence of noise on voice perturbation outputs obtained by three different voice analysis programs, and to show the software more immune to noise. Material and Methods: For this purpose, 10 natural and 10 semi-synthetic voice samples were recorded. They were mixed with environmental noise and white noise. The unmixed and mixed signals were analyzed by Dr. Speech, MDVP and Praat. Three frequency perturbation outputs (jitter percent, relative average perturbation and pitch perturbation quotient) and two amplitude perturbation outputs (shimmer percent and amplitude perturbation quotient) were obtained. The unmixed and mixed signals were compared. Correlations were calculated between natural unmixed and natural mixed ones. Results: The frequency perturbation outputs obtained by Dr. Speech and Praat seemed to be less affected by noise. However, the amplitude perturbation values measured by three systems were severely affected by noise, but Praat's performance found mildly better than the others'. Correlation analyses for 10 items (five parameters x two noise situations) revealed that there were perfect correlations (r= 1.000) regarding six items for Praat, three items for Dr. Speech and one item for MDVP. Conclusion: As a conclusion, it was decided that Praat was the most immune one to noise among three analysis systems, followed by Dr. Speech and MDVP, respectively

Reliability and validity of the Turkish version of the Vocal Fatigue Index

Sirin, Seher/0000-0002-2982-9379WOS:000613005100034PubMed: 32421276Background/aim: The aim of this study is to evaluate the reliability and validity of the Turkish version of the Vocal Fatigue Index (VFI). Materials and methods: The study was conducted with 535 participants including 285 patients with voice disorders and 250 healthy controls. Internal consistency and test-retest reliability were calculated for the reliability analysis. 'I he mean VFI factor scores of both groups were compared. The strength and direction of the relation between VFI and Voice-Related Quality of Life (V-RQOL) measure was evaluated for the validity analysis. Results: The Cronbach's alpha coefficient of VFI factor scores was found to be 0.920 for tiredness and avoidance of voice use, 0.879 for physical discomfort with voice use, and 0.882 for improvement of symptoms with voice rest. The test-retest reliability revealed 0.877 for the tiredness and avoidance of voice use, 0.913 for the physical discomfort with voice use, and 0.820 for the improvement of symptoms with voice rest. When compared with healthy individuals, VFI factor scores were statistically significant higher in patients with voice disorders. The V-RQOL scores decreased significantly as the VFI scores increased. Conclusion: The Turkish version of the VFI is a good reliable and valid instrument for evaluating vocal fatigue symptoms in the Turkish-speaking community

Weathered Fly Ash Does Not Affect Soil and Biosolid Carbon Mineralization

Fly ash and biosolid wastes can be mixed and applied to soil as a means of disposal. A significant decline in soil respiration following waste application indicates restricted activities of functional microbial populations. Weathering decreases salinity and neutralizes alkalinity in fly ash, but there is little information on the effects of unweathered fly ash and biosolid mixtures on soil carbon (C) mineralization. The objective of this study was to determine the effects of a weathered fly ash–limestone scrubber residue (LSR) mixed with an aerobically digested biosolid on soil respiration in a laboratory incubation study. Biosolids significantly increased carbon dioxide (CO2) production (p \u3c 0.05), but up to 6.75% (w/w) fly ash did not. Mean total C mineralization was 770 mg CO2‐C kg−1 soil in the control and 3,810 mg CO2‐C kg−1 soil in the 6.75% (w/w) biosolid treatment. Fly ash with neutral pH and low salinity appears unlikely to affect soil and biosolid C mineralization

Doxycycline down-regulates matrix metalloproteinase expression and inhibits NF-κB signaling in LPS-induced PC3 cells

Introduction. Matrix metalloproteinase enzymes (MMPs) play important role in inflammation, malignant cell proliferation, invasion and angiogenesis by mediating extracellular matrix degradation. Doxycycline, a synthetic tetracycline, behaves as a MMP inhibitor at a subantimicrobial dose and inhibits tumor cell proliferation, invasion and angiogenesis. The aberrant activity of nuclear factor kappa B (NF-κB) causes activation of MMPs and thereby proliferation and invasion of cancer cells. The aim of this study was to investigate the effects of doxycycline on the expression of MMPs in lipopolysaccharide (LPS)-induced PC3 human prostate cancer cells and the possible role of NF-κB signaling. Material and methods. PC3 cells were incubated with LPS (0.5 μg/mL) for 24 h in the presence or absence of doxycycline (5 μg/mL). The effects of LPS and doxycycline on the expressions of MMP-2, MMP-8, MMP-9, MMP-10, NF-κB/p65, IκB-α, p-IκB-α, IKK-β were examined by Western blotting and immunohistochemistry in PC3 cells. Furthermore, relative proteinase activities of MMP-2 and MMP-9 were determined by gelatin zymography. Results. LPS increased expression and activity of MMP-9 and expression of MMP-8, MMP-10, NF-κB /p65, p-IκB-α, IKK-β and doxycycline down-regulated its effects with the exception of MMP-10 expression. The expression of MMP-2 and IκB-α was affected by neither LPS nor doxycycline. Conclusions. Our findings indicate that doxycycline inhibits the expression of various MMPs and NF-κB signaling may play a role in the regulation of MMPs expression in LPS-induced PC3 human prostate cancer cells

Evaluation of Vestibulo-Ocular Reflex (VOR) in Tinnitus Patients with Normal Hearing

WOS:000620339200003PubMed: 33605215OBJECTIVES: This study aimed to evaluate the correlation between tinnitus parameters (duration, severity, reaction, handicap levels) and vestibule-ocular reflex (VOR) gain values in patients with tinnitus with normal hearing without vertigo or any other complaints and to compare the VOR gains with a healthy group. MATERIALS and METHODS:The study group consisted of 30 individuals aged between 18 and 65 years who suffered from tinnitus but not from hearing loss and vertigo. The control group also consisted of 30 individuals who were categorized as healthy adults. The tinnitus handicap inventory, tinnitus reaction questionnaire, and tinnitus handicap questionnaire were applied to each individual in the tinnitus group, and the video head impulse test (VHIT) was conducted in 2 groups. RESULTS: Statistically, a significant difference was found between the 2 groups in terms of VOR gain values in horizontal and vertical semicircular canal planes (p0.05). CONCLUSION: Considering the lower VOR gain values of the study group than the control group, these patients may need to be followed up for vestibular dysfunction associated with tinnitus, which can be a symptom of peripheral vestibular disorder. Moreover, this study will contribute to t he literature because we determined a high-frequency component of VOR by VHIT, which was used to evaluate the relationship between tinnitus parameters and peripheral vestibular function