27 research outputs found
Global production and free access to Landsat-scale Evapotranspiration with EEFlux and eeMETRIC
EEFlux (Earth Engine Evapotranspiration Flux) is a version of the METRIC (mapping evapotranspiration at high resolution with internal calibration) application that operates on the Google Earth Engine (EE). EEFlux has a web-based interface and provides free public access to transform Landsat images into 30 m spatial evapotranspiration (ET) data for terrestrial land areas around the globe. EE holds the entire Landsat archive to power EEFlux along with NLDAS/CFSV2 gridded weather data for estimating reference ET. EEFlux is a part of the upcoming OpenET platform (https://openetdata.org/ ) that has leveraged nonprofit funding to provide ET information to all of the lower 48 states for free, as a means to foster water exchange between agriculture, cities and environment (Melton et al., 2020). The METRIC version in OpenET is named eeMETRIC, and includes cloud detection and time integration of ET snapshots into monthly ET estimates. EEFlux and eeMETRIC employ METRIC’s “mountain” algorithms for estimating aerodynamics and solar radiation in complex terrain. Calibration is automated and ET images are computed for download in seconds using EE’s large computational capacity
Sensitivity of evapotranspiration retrievals from the METRIC processing algorithm to improved radiometric resolution of Landsat 8 thermal data and to calibration bias in Landsat 7 and 8 surface temperature
We made an assessment on the use of 12-bit resolution of Landsat 8 (L8) on evapotranspiration (ET) retrievals via the METRIC process as compared to using 8-bit resolution imagery of previous Landsat missions. METRIC (Mapping Evapotranspiration at high Resolution using Internalized Calibration) is an ET retrieval system commonly used in water and water rights management where the surface energy balance process is coupled with an extreme- end point calibration process to remove most impacts of systematic bias in remotely sensed inputs. We degraded L8 thermal images by grouping sequential digital numbers to reduce the apparent numerical resolution and then recomputed ET using METRIC and compared to nondegraded ET products. The use of 8-bit thermal data did not substantially impair the accuracy of ET retrievals derived from METRIC, as compared to the use of 12-bit thermal data. The largest error introduced into ET was \u3c1%. We also compared ET retrieved from images processed during the L8 and Landsat 7 (L7) March 2013 underfly to assess differences in ET caused by differences in signal to noise ratio (SNR) and scaling of the two systems.
We evaluated the impact of bias in land surface temperature (LST) retrievals on ET determination using the CIMEC calibration approach (Calibration using Inverse Modeling using Extreme Member Calibration) employed in METRIC by introducing globally systematic biases into LST retrievals from L7 and L8 and comparing to ET from non-biased retrievals. The impacts of the introduction of both additive and multiplicative biases into surface temperature on ET were small for the three regions of the US studied, and for both L7 and L8 satellite systems. An independent study showed that METRIC-produced ET compared to within 3% of measured ET for the California site. The study assessed the impact of the February 2014 recalibration of L8 thermal data that caused a 3 K downward shift in LST estimation and changed reflectance values by about 0.7%. We found that the use of the recalibrated LST and shortwave data sets in METRIC did not change the accuracy of ET retrievals due to the automatic compensation for systematic biases employed by METRIC
EVALUATION OF REGIONAL CLIMATE MODELS WITH REMOTELY SENSED EVAPOTRANSPIRATION DATA
Water is one of the most precious resources on Earth. Managing water resources is a complex discipline that requires accurate data, which in turn means that the management of water resources is limited by the availability and quality of these datasets. Evapotranspiration (ET) is one of these key datasets, but is also one that is lacking in large-scale spatial distribution with traditional methods such as weighing lysimeters or Bowen ratio. This is a quantity that needs to be evaluated in regional and global climate models since it is a substantial component of the land surface-atmosphere interaction. In order to overcome the limitations imposed by point wise calculation of ET, a new dataset based on a surface energy balance model Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) constrained by Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery have been developed. A Fully Automated Python implementation of METRIC model, as well as a script which generates 15-day Reference ET Fraction (ETrF) composites were needed and developed to cover the Contiguous United States (CONUS) due to the high computational time for manual processing of METRIC. In this study, the new ET dataset will be used to evaluate how well the Weather Research and Forecasting Model, coupled with Community Land Model\u27s (WRF-CLM) as well as Noah-MP and Bucket Land Surface Model, evaluate ET. CLM, Noah-MP and Bucket are the models used to understand the processes between land and atmosphere and also climate change, and contain crucial but poorly known parameterizations for ET.
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Evaluation of Clinical and Radiological Results of Humeral Diaphyseal Fractures with Treated Sarmiento Brace
WOS: 000515092400005PubMed: 32226678Aim in our study, we aimed to evaluate the duration and rate of the union of adult humerus diaphysis fractures treated with a functional brace. Methods Forty-six adult patients admitted to our hospital with humeral diaphyseal fracture between January 2010 and April 2014 and treated with a functional brace were evaluated retrospectively. the demographic data, fracture type, level of fracture, and presence of bone union of the patients were evaluated from clinic records. the Disabilities of the Arm, Shoulder and Hand (Quick-DASH) questionnaire score of the patients was registered for patients and analyzed, and its correlation with parameters such as patient age and fracture bone union time was evaluated. Results It was observed that of the patients with the mean age of 45.5 years, six (13.6%) had non-union and five had delayed bone union (10.86%). Three (6.5%) patients had radial nerve injury, and all recovered without sequelae. Out of the patients with the bone union, 12 (30%) had an angulation above give degrees, and 3 (7.5%) had radiological shortness. the mean Quick-DASH score was 6.7, and there was no statistically significant correlation with parameters such as fracture type, level, angulation, radiological shortness and radial nerve involvement (p>0.05). Conclusions A functional brace is a good treatment choice with low complication rates and has satisfactory bone union rates in humerus diaphyseal fractures
A Rare Complication of Cochlear Implantation After Magnetic Resonance Imaging: Reversion of the Magnet.
Cochlear implants are mechanical devices used for patients with severe sensory-neural hearing loss, which has an inner magnet. It is proven that 1.5 Tesla magnetic resonance imaging (MRI) scanners are safe to use in patients with cochlear implant. In our patient, the authors aim to introduce a rare complication caused after a 1.5 Tesla MRI scanning and the management of this situation; the reversion of the magnet of the implant without displacement and significance of surgery in management
Atypical Metastasis to the Head and Neck Region: An Analysis of 11 Patients
Objective: We present 11 patients with distant metastases to the head and neck from an infraclavicularly located primary tumor and discuss the management strategies including the clinical presentation, treatment modalities, and prognosis
Effect of anticholinergic burden on the development of dementia in older adults with subjective cognitive decline
OBJECTIVE: Data on the effect of anticholinergic cognitive burden (ACB) in older adults with subjective cognitive decline (SCD) are limited. We aimed to study whether ACB increases the future risk of dementia in older adults with SCD. METHODS: The retrospective cohort analysis was carried out on 1496 older adults. Out of those, 109 older patients with SCD followed up over 36 months were studied. They were divided into two groups according to cognitive status at last visit: group I included the subjects with SCD who did not progress to dementia and group II included those who progressed to dementia. The drugs with anticholinergic effects that were received by subjects three months or more were identified from records. The drugs were categorized as having absent (ACB = 0), possible (ACB = 1), and definite (ACB = 2) anticholinergic properties based on an ACB scale. ACB was calculated for each subject by adding the score of each drug and classified as no or low ACB (ACB ≤ 2) and high ACB (ACB ≥ 3). RESULTS: The mean age of all subjects was 72.5 ± 6.3 years and 66.1% of the sample was female. The median follow-up time for all subjects was 75 months (range, 36–185). Fifteen (13.8%) of 109 participants with baseline SCD developed dementia. High ACB was present in 12 subjects (12.8%) in group I and 7 subjects (46.7%) in group II (p = .001). The 75–84 and 85+ age groups (hazard ratio (HR) = 3.595; CI: 1.117–11.574; p = .032 and HR = 12.203; CI: 2.889–51.537; p = .001, respectively), hypertension (HR = 7.835; CI: 1.020–60.189; p = .048), and high ACB (HR = 4.312; CI: 1.563–11.899; p = .005) were found to be possible risk factors for dementia among subjects with SCD in the univariate model. In the final multivariate Cox regression model, subjects with high ACB had a 4.2-fold the risk of the development of dementia. Metoprolol (28.6%), trazodone (21.4%), and trospium (12.9%) were leading used drugs with anticholinergic properties. Among subjects with a total ACB score ≥ 3, the majority were on trospium (29.0%), followed by metoprolol (16.2%), paroxetine (16.2%), and trazodone (16.2%). CONCLUSION: We found that high ACB increases 4.2-fold the risk of the development of dementia in older adults with SCD in long-term follow up. The results of our study are promising, however, the effect of ACB on cognitive status among subjects with SCD is still lacking. To clarify the association between ACB and the risk of dementia, large and longer prospective studies are needed in this population