18 research outputs found
First-Principle Dynamic Electro-Thermal Numerical Model of a Scanning Radiometer for Earth Radiation Budget Applications
Low Earth Observing instruments that are used to monitor the incoming solar and outgoing long wave radiation have been a crucial part of studying the Earths radiation budget for the past three decades. These instruments go through several robust design phases followed by vigorous ground calibration campaigns to set their baseline characterization spectrally, spatially, temporally and radiometrically. The knowledge from building and calibrating these instruments has aided in technology advancements and the need for developing more accurate instruments has increased. In order to understand the on-ground instrument performance, NASA Langley Research Center has partnered with the Thermal Radiation Group of Virginia Tech to develop a first-principle, dynamic, electrothermal, numerical model of a scanning radiometer that can be used to enhance the interpretation of an Earth radiation budget-like instrument on orbit. This paper will summarize the current efforts of developing this high-fidelity end-to-end model and also highlight how it can be applied to an Earth radiation budget instrument
Comparison of post-dural puncture headache incidence among patients undergoing spinal anaesthesia for elective caesarean section by using quincke 25-G and 29-G spinal needles
Background: Multiple complications including hypotension, nausea, vomiting, urinary retention, transient neurological symptoms and headache have been associated with spinal anaesthesia. Importantly, post dural puncture headache (PDPH) varies with the type and size of spinal needle employed for inducing anaesthesia. Here, we aimed to compare the frequency of PDPH in patients underwent spinal anaesthesia for elective caesarean section using 25-gauge (G) and 29-G Quincke spinal needle.Methods: We designed a randomized control trial at Obstetrics and Gynecology Operation Theatres, Jinnah Hospital, Lahore. A total of 152 patients having age 30.28±8.21 years were enrolled in the study and divided into two groups each comprising of 76 patients. In group 1, spinal anaesthesia was performed using 25-G Quincke spinal needle while in group 2 spinal anaesthesia was administered employing 29-G Quincke spinal needle. A standard dose of 10.5-12.0 mg (1.4-1.6 ml) of 0.75% bupivacaine is infiltrated in subarachnoid space at lumber region L3-L4 or L4-L5 following aseptic measures. The patients were evaluated for PDPH during the follow up period.Results: The previous history of PDPH was observed in 20.39% patients. The comparative study showed that the PDPH was observed in 12 (15.7%) patients in group 1 while the group 2 revealed PDPH in only 2 (2.6%) patients.Conclusions: Thus 29-G spinal needle can be regarded as a better option to reduce PDPH in patients subjected to spinal anaesthesia for elective cesarean in contrast to the use of 25-G Quincke spinal needle
Linking lidar multiple scattering profiles to snow depth and snow density: an analytical radiative transfer analysis and the implications for remote sensing of snow
Lidar multiple scattering measurements provide the probability distribution of the distance laser light travels inside snow. Based on an analytic two-stream radiative transfer solution, the present study demonstrates why/how these lidar measurements can be used to derive snow depth and snow density. In particular, for a laser wavelength with little snow absorption, an analytical radiative transfer solution is leveraged to prove that the physical snow depth is half of the average distance photons travel inside snow and that the relationship linking lidar measurements and the extinction coefficient of the snow is valid. Theoretical formulas that link lidar measurements to the extinction coefficient and the effective grain size of snow are provided. Snow density can also be derived from the multi-wavelength lidar measurements of the snow extinction coefficient and snow effective grain size. Alternatively, lidars can provide the most direct snow density measurements and the effective discrimination between snow and trees by adding vibrational Raman scattering channels
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Production of a Multi-decadal Earth Radiation Budget Climate Data Record: Balancing Accuracy, Precision, and Data Availability to Meet the Needs of the Community
NASA’s Earth Radiation Budget Science Team, ERB-ST, (Previously known as the CERES Science Team) is a multi-disciplinary team led out of NASA’s Langley Research Center which has the responsibility for governance of the nation’s multi-decadal Earth Radiation Budget Climate Data Record, ERB CDR. The Science Data Processing System which produces the ERB-CDR is highly complex, producing Level one through Level 4 products. The system ingests data from 19 different instruments on 11 different spacecraft (6 GEO and 5 LEO) as well as other ancillary information, producing 25 different products with consistent TOA, Surface, and atmospheric radiative fluxes, cloud and aerosol properties on multiple spatial and temporal scales. Spatial scales vary from instantaneous/pixel (25 km), 1-deg grid, zonal, regional and global means while temporal scales vary across instantaneous, hourly, 3 hourly to monthly scales. Accuracy and precision values vary across the various spatial and temporal scales, with the long-term goal of measuring decadal trends of better than 0.3 W/m^2 per decade. Instrument calibration and precision, as measured through the post-launch protocols, is one of many considerations that drive the decision to reprocess, others include, but are not limited to validation and instantiation of new algorithms across all levels of products, outside teams reprocessing the products we ingest, the launch of new instrumentation to replace operational weather imagers on Geo satellites, updates to processing hardware, and of course resource availability. These all need to be managed/considered in order to provide the global community products of sufficient accuracy and precision on a time-scale which allows continued advancement and discovery of key scientific questions such that policy makers may make informed decisions.
This presentation will highlight the process the Earth Radiation Budget Science Team currently utilizes to guide reprocessing decisions, identifying lessons learned and best practices
Russia-Ukraine war and systemic risk: Who is taking the heat?
The Russia–Ukraine conflict has increased systemic vulnerabilities of the global financial system. We develop a database of news events and investigate the systemic risk implications of the conflict on Russia, Ukraine, France, Germany, Italy, the UK, the USA, and China. Results show that systemic instability costs of the conflict go beyond Russia and Ukraine. Sanctions cause systemic risk spillovers to European countries and the USA. Study findings caution against the accumulation of systemic risk as sanctions may adversely affect the rest of the world aside from the main target - Russia
Numerical Focusing of a Wide-Field-Angle Earth Radiation Budget Imager Using an Artificial Neural Network
Narrow field-of-view scanning thermistor bolometer radiometers have traditionally been used to monitor the earth’s radiant energy budget from low earth orbit (LEO). Such instruments use a combination of cross-path scanning and along-path spacecraft motion to obtain a patchwork of punctual observations which are ultimately assembled into a mosaic. Monitoring has also been achieved using non-scanning instruments operating in a push-broom mode in LOE and imagers operating in geostationary orbit. The current contribution considers a fourth possibility, that of an imager operating in LEO. The system under consideration consists of a Ritchey-Chrétien telescope illuminating a plane two-dimensional microbolometer array. At large field angles, the focal length of the candidate instrument is field-angle dependent, resulting in a blurred image in the readout plane. Presented is a full-field focusing algorithm based on an artificial neural network (ANN). Absorbed power distributions on the microbolometer array produced by discretized scenes are obtained using a high-fidelity Monte Carlo ray-trace (MCRT) model of the imager. The resulting readout array/scene pairs are then used to train an ANN. We demonstrate that a properly trained ANN can be used to convert the readout power distribution into an accurate image of the corresponding discretized scene. This opens the possibility of using an ANN based on a high-fidelity imager model for numerical focusing of an actual imager
Numerical Focusing of a Wide Field-of-View Instrument for Monitoring the Planetary Energy Budget
Wide field-of-view optical instruments based on Ritchey-Crétien telescopes have been proposed to replace narrow field-of-view scanning instruments for Earth radiation budget monitoring applications. A disadvantage of such instruments is that they are subject to significant focal plane distortion. A novel numerical focusing scheme is proposed and demonstrated using a Monte Carlo ray-trace-based simulation of the performance of a candidate instrument. Results are presented which indicate that image recovery error can be significantly reduced using the proposed algorithm
Botany, nutritional value, phytochemical composition and biological activities of quinoa
Quinoa is a climate-resilient food grain crop that has gained significant importance in the last few years due to its nutritional composition, phytochemical properties and associated health benefits. Quinoa grain is enriched in amino acids, fiber, minerals, phenolics, saponins, phytosterols and vitamins. Quinoa possesses different human-health promoting biological substances and nutraceutical molecules. This review synthesizes and summarizes recent findings regarding the nutrition and phytochemical properties of quinoa grains and discusses the associated biological mechanisms. Quinoa grains and grain-based supplements are useful in treating different biological disorders of the human body. Quinoa is being promoted as an exceptionally healthy food and a gluten-free super grain. Quinoa could be used as a biomedicine due to the presence of functional compounds that may help to prevent various chronic diseases. Future research needs to explore the nutraceutical and pharmaceutical aspects of quinoa that might help to control different chronic diseases and to promote human health.King Saud University | Ref. RG-1440-05