757 research outputs found
Human visual performance during deployment of ALSEP in a lunar visual environment
The purpose of this investigation is to analyze the light reflected from the lunar surface, the light reflected from ALSEP, the contrast between the luminance of ALSEP and the lunar surface, the absence of scattered light, the capabilities of the astronaut, and effect on human visual performance when operating in this lunar visual environment.prepared by W. L. McIntire
Impact of Blackbody Warm-Up Cool-Down Cycle on the Calibration of Aqua MODIS and S-NPP VIIRS Thermal Emissive Bands
This paper evaluates the calibration quality during the blackbody (BB) warm-up cool-down cycle for thermal emissive bands onboard Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and Suomi National Polar-orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS). This evaluation utilizes data from Aqua MODIS Collection 6 Level-1B products and VIIRS Sensor Data Records in 6-min granule format provided by the NASA Land Science Investigator-led Processing System. Nearly simultaneous hyperspectral measurements from the Aqua Atmospheric Infrared Sounder (AIRS) and the S-NPP Cross-track Infrared Sounder (CrIS) are used as references for MODIS and VIIRS, respectively. Each AIRS footprint of 13.5 km is co-located with multiple MODIS pixels while each CrIS field of view of 14 km is co-located with multiple VIIRS pixels. The corresponding AIRS-simulated MODIS and CrIS-simulated VIIRS radiances are derived by convolutions based on sensor-dependent relative spectral response functions. In this paper, the analysis mainly focuses on the bands that are used in sea surface temperature products. The results show that there is virtually no impact for MODIS bands 22 and 23 and bands 31 and 32 for a BB temperature below 290 K; however, when the BB temperature increases above 290 K, the impact is up to 0.3 K for bands 22 and 23 and 0.05 K for bands 31 and 32, respectively. For VIIRS, BB temperature-dependent drifts are observed in M15 and M16, which can reach 0.15 and 0.1 K, respectively, over the operational BB temperature range and the VIIRS brightness temperature range
JPSS-2 VIIRS Polarization Sensitivity Performance Comparison with Heritage VIIRS Sensors
The Joint Polar Satellite System 2 (JPSS-2) is the follow-on for the Suomi-National Polar-orbiting Partnership (S-NPP) and Joint Polar Satellite System 1 (JPSS-1) missions. These spacecrafts provide critical weather and global climate products to the user community. A primary sensor on both JPSS and S-NPP is the Visible-Infrared Imaging Radiometer Suite (VIIRS) with Earth observations covering the Reflective Solar Band (RSB), Thermal Emissive Band (TEB) and Day Night Band (DNB) spectral regions. The VIIRS Sensor Data Records (SDRs) contain the calibrated Earth observations that are used in Environmental Data Record (EDR) products such as Ocean Color/Chlorophyll (OCC) and Sea Surface Temperature (SST). This SDR calibration is performed using unpolarized sources such as the Solar Diffuser (SD) for the RSBs and an On-Board Calibrator BlackBody (OBCBB) for the TEBs. Therefore, polarized Earth scenes will have radiometric bias errors within the SDRs based on how sensitive VIIRS is to polarized illumination and is corrected in some EDR algorithms. This paper will discuss the JPSS-2 VIIRS polarization characterization methodology, polarization sensitivity results and compare its performance to its predecessors S-NPP and JPSS-1 VIIRS. Optical modifications to the JPSS-2 VIIRS sensor to address heritage polarization sensitivity issues will be discussed
Using an Augmented Reality App for Flight Training
As the global demand for aviation pilots continues to drastically increase, flight schools are experiencing a large influx of ab-initio flight students. Such flight training programs are seeking innovative, cutting-edge technologies to support these students and expedite their flight training. The ARAir app, a custom app developed by our team, was designed for ab-initio pilots training at the Embry-Riddle Prescott campus. The initial implementation in Spring 2021 included phonetic alphabet practice and strategic radiotelephony that allows students to practice in a self-paced environment with immediate corrective feedback at various levels of complexity. Students can compete against themselves to improve phonetic alphabet knowledge, create initial radio transmissions, read back ATC instructions, and manipulate an aircraft to the correct intended location at the KPRC airport. Based on the survey and interview feedback collected after the initial implementation, additional support for checklist memorization using the Augmented Reality (AR) feature was added to the ARAir app. This presentation will report students’ learning experience with the improved ARAir in the second implementation in Spring 2022
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The role of small mammals as dispersers of mycorrhizal fungal spores within variously managed forests and clearcuts
Small-mammal community composition, microhabitat selection, and
dispersal of mycorrhizal fungal spores were studied in southwestern
Oregon. Sampled habitats exhibited structural variation resulting
from silvicultural practices.
In 1981, the effect of clearcut treatment on these phenomena was
evaluated. In 1982, the effect of forest structure was studied.
Discriminant function analysis (DFA) and principal component
analysis (PCA) were used to distinguish and characterize clearcut,
edge, and forest habitats of study sites. Microhabitat preferences
of small-mammal species were examined using DFA. For each habitat
in every site, species diversities and related community parameters
were calculated. Relationships among habitat structure,
microhabitat preferences, and community composition parameters were
examined using partial correlation analysis. Distances moved by
small mammals between the clearcuts and forests were determined for
common species. Spore abundances in fecal pellets were calculated
for small-mammal species that moved among the three habitats.
In 1981, 1273 individuals of 11 species were captured. Deer
mice (Peromyscus maniculatus) and chipmunks (Tamias spp.) comprised
81.6 percent of all trapped animals. As degree of forest structure
increased, the relative abundances of deer mice decreased and those
of chipmunks and red-backed voles increased. Thus, small-mammal
community composition changed with increasing habitat complexity.
Only deer mice and chipmunks moved among all habitats, and no
consistent effect of clearcut treatment was observed on movements of
either species. Chipmunks excreted more kinds and greater
quantities of fungal spores than deer mice.
In 1982, 1287 individuals of seven small-mammal species were
captured; golden-mantled ground squirrels (Spermophilus lateralis),
deer mice, and yellow pine chipmunks (Tamias amoenus) were the most
numerous. Relative abundances of small-mammal species varied with
overall habitat complexity. As degree of forest structure
increased, the relative proportions of forest specialists influenced
small-mammal community composition.
Ground squirrels, deer mice, and chipmunks moved among the three
habitats. Differences in movements between habitats among these
species reflected habitat affinities. Abundance of spores in feces
was highest for Siskiyou chipmunks (Tamias siskiyou) followed by
ground squirrels, deer mice, and yellow pine chipmunks. For all
small-mammal species combined, the greatest spore abundance was
recorded for samples from the least disturbed forest.
Small-mammal and fungal communities respond to habitat
alteration. Principal small-mammal mycophagists and fungi occur in
greater numbers in minimally disturbed forests and untreated
clearcuts. To maximize inocula availability in disturbed sites,
adjacent forests and the understory in clearcuts should be left
undisturbed
The Effects Of Caffeine On Athletic Performance
Athletes who use caffeine before exercising or competition may be upgrading themselves more than they realize. Caffeine is classified as a stimulant and is the most commonly used drug in the world. Caffeine has the same affects that amphetamines and cocaine have, just to a lesser degree. Caffeine crosses the membranes of all the body’s tissues. It can exert effects on the central nervous system and the peripheral tissues that result in physiological effects. Studies have shown that caffeine improves performance in a variety of different activities. This stimulant has been shown to be a powerful ergogenic aid that is beneficial in athletic training and performance. Caffeine has been found to increase speed and power, improve the length of training, and assist the athlete in resisting fatigue. Caffeine has been found to stimulate the brain, which contributes to clearer thinking and ability to concentrate more intensely on the task at hand. Studies have shown that up to 25% of athlete’s ages 11-18 years old have used caffeine in an effort to increase their athletic performances. Because of caffeine’s effect on the body and its ability to increase an athlete’s performance, Olympic Committees have debated on whether caffeine should be tested before the Olympic Games
Prelaunch and On-Orbit Electronic Calibration for Earth Observing Instruments
"The Electronic Calibration (Ecal) tests are performed during various stages of instrument development to examinethe linearity of the instrument electronics. During this process, charges with stepwise increments are injected inthe analog electronics circuitry to generate a ramp signal that can be used to characterize any nonlinearities in theelectronics. The prelaunch characterization of MODIS (on the Terra and Aqua platforms) and VIIRS (on SNPP,JPSS-1 and JPSS-2) involved a regular evaluation of the electronics linearity using the Ecal tests. On orbit,the Ecal tests have been regularly performed over the mission for both the MODIS instruments to derive theelectronics gain and linearity. Unlike MODIS, the Ecal tests on the VIIRS instruments are performed on an as-needed basis. To date, no Ecal tests were performed for S-NPP VIIRS on orbit. The VIIRS instrument on JPSS-1(now NOAA 20) was launched on November 18, 2017. An Ecal test was performed to support the instrumentsinitial post-launch performance assessment. Shortly after the first on-orbit emissive band calibration, degradationin the instrument gain was observed for the LWIR bands (M15, M16 and I5). As a part of the investigationrelated to this anomaly, a second Ecal test was performed and results were compared with the prelaunch results.In this paper, we discuss the prelaunch Ecal tests and representative results from MODIS and VIIRS prelaunchcharacterization. Also, discussed are the on-orbit results from the two MODIS instruments as well as from therecently launched VIIRS instrument.
Analysis of JPSS J1 VIIRS Polarization Sensitivity Using the NIST T-SIRCUS
The polarization sensitivity of the Joint Polar Satellite System (JPSS) J1 Visible Infrared Imaging Radiometer Suite (VIIRS) measured pre-launch using a broadband source was observed to be larger than expected for many reflective bands. Ray trace modeling predicted that the observed polarization sensitivity was the result of larger diattenuation at the edges of the focal plane filter spectral bandpass. Additional ground measurements were performed using a monochromatic source (the NIST T-SIRCUS) to input linearly polarized light at a number of wavelengths across the bandpass of two VIIRS spectral bands and two scan angles. This work describes the data processing, analysis, and results derived from the T-SIRCUS measurements, comparing them with broadband measurements. Results have shown that the observed degree of linear polarization, when weighted by the sensor's spectral response function, is generally larger on the edges and smaller in the center of the spectral bandpass, as predicted. However, phase angle changes in the center of the bandpass differ between model and measurement. Integration of the monochromatic polarization sensitivity over wavelength produced results consistent with the broadband source measurements, for all cases considered
Association Between Lack of Access to a Neighborhood Park and High Blood Pressure in the Philadelphia Metropolitan Area
INTRODUCTION: Studies have shown a lower risk of high blood pressure (HBP) among people who live near parks; however, little information exists on how feeling safe and comfortable visiting the park affects blood pressure. We identified associations between neighborhood park access, comfort visiting a park, and HBP to understand how these factors may contribute to disparities in HBP prevalence.
METHODS: The 2018 Southeastern Pennsylvania Household Health Survey of 3,600 residents in the Philadelphia metropolitan area asked if respondents had ever been told they had HBP and whether they had a neighborhood park or outdoor space that they were comfortable visiting during the day. To assess the association between park access and HBP, we built multilevel logistic models to account for variation in HBP by zip code. We examined the effect modification of perceptions of park access (having a neighborhood park, not having a neighborhood park, or having a neighborhood park but not comfortable visiting it) and HBP by race, education, and poverty status.
RESULTS: Both not having a neighborhood park and having a park but not feeling comfortable visiting it were associated with higher unadjusted odds of HBP, 70% and 90%, respectively, compared with having a neighborhood park. Adjusted odds ratios for the lack-of-park responses remained significant (no neighborhood park, adjusted odds ratio [aOR] = 1.4; 95% CI, 1.1-1.7; neighborhood park but not comfortable visiting, aOR = 1.4; 95% CI, 1.03-2.0). A significant gradient was observed for Black respondents compared with White respondents with odds of HBP increasing by perceptions of park access (aOR = 1.95 for people with a park; aOR = 2.69 for those with no park; aOR = 3.5 for people with a park that they are not comfortable visiting).
CONCLUSION: Even accounting for other risk factors for HBP, not having a neighborhood park or not feeling comfortable visiting one may influence individual HBP. Neighborhood factors that deter park access may contribute to racial disparities in HBP
An evidence-based definition of anemia for singleton, uncomplicated pregnancies
BACKGROUND: The definition for anemia in pregnancy is outdated, derived from Scandinavian studies in the 1970\u27s to 1980\u27s. To identity women at risk of blood transfusion, a common cause of Severe Maternal Morbidity, a standard definition of anemia in pregnancy in a modern, healthy United States cohort is needed.
OBJECTIVE: To define anemia in pregnancy in a United States population including a large county vs. private hospital population using uncomplicated patients.
MATERIALS AND METHODS: Inclusion criteria were healthy women with the first prenatal visit before 20 weeks. Exclusion criteria included preterm birth, preeclampsia, hypertension, diabetes, short interval pregnancy (\u3c18 months), multiple gestation, abruption, and fetal demise. All women had iron fortification (Ferrous sulfate 325 mg daily) recommended. The presentation to care and pre-delivery hematocrits were obtained, and the percentiles determined. A total of 2000 patients were included, 1000 from the public county hospital and 1000 from the private hospital. Each cohort had 250 patients in each 2011, 2013, 2015, and 2018. The cohorts were compared for differences in the fifth percentile for each antepartum epoch. Student\u27s t-test and chi-squared statistical tests were used for analysis, p-value of ≤0.05 was considered significant.
RESULTS: In the public and private populations, 777 and 785 women presented in the first trimester while 223 and 215 presented in the second. The women at the private hospital were more likely to be older, Caucasian race, nulliparous, and present earlier to care. The fifth percentile was compared between the women in the private and public hospitals and were clinically indistinguishable. When combining the cohorts, the fifth percentile for hemoglobin/hematocrit was 11 g/dL/32.8% in the first trimester, 10.3 g/dL/30.6% in the second trimester, and 10.0 g/dL/30.2% pre-delivery.
CONCLUSIONS: Fifth percentile determinations were made from a combined cohort of normal, uncomplicated pregnancies to define anemia in pregnancy. Comparison of two different cohorts confirms that the same definition for anemia is appropriate regardless of demographics or patient mix
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