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

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.

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

Risk Factors Associated with False Positive HIV Test Results in a Low-Risk Urban Obstetric Population

Objective. To examine risk factors for false positive HIV enzyme immunoassay (EIA) testing at delivery. Study Design. A review of pregnant women who delivered at Parkland Hospital between 2005 and 2008 was performed. Patients routinely received serum HIV EIA testing at delivery, with positive results confirmed through immunofluorescent testing. Demographics, HIV, hepatitis B surface antigen (HBsAg), and rapid plasma reagin (RPR) results were obtained. Statistical analyses included Pearson's chi-square and Student's t-test. Results. Of 47,794 patients, 47,391 (99%) tested negative, 145 (0.3%) falsely positive, 172 (0.4%) positive, and 86 (0.2%) equivocal or missing HIV results. The positive predictive value of EIA was 54.3%. Patients with false positive results were more likely nulliparous (43% versus 31%, P < 0.001) and younger (23.9 ± 5.7 versus 26.2 ± 5.9 years, P < 0.001). HIV positive patients were older than false positive patients and more likely positive for HBsAg and RPR. Conclusion. False positive HIV testing at delivery using EIA is associated with young maternal age and nulliparity in this population

Glucosyltransferase phase variation in Streptococcus gordonii modifies adhesion to saliva-coated hydroxyapatite surfaces in a sucrose-independent manner

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72317/1/j.1399-302X.1992.tb00521.x.pd