The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NACs) are on the NASA Lunar Reconnaissance Orbiter (LRO). The WAC is a 7-color push-frame camera (100 ...and 400 m/pixel visible and UV, respectively), while the two NACs are monochrome narrow-angle linescan imagers (0.5 m/pixel). The primary mission of LRO is to obtain measurements of the Moon that will enable future lunar human exploration. The overarching goals of the LROC investigation include landing site identification and certification, mapping of permanently polar shadowed and sunlit regions, meter-scale mapping of polar regions, global multispectral imaging, a global morphology base map, characterization of regolith properties, and determination of current impact hazards.
The Mars 2020
Perseverance
rover is equipped with a next-generation engineering camera imaging system that represents an upgrade over previous Mars rover missions. These upgrades will improve the ...operational capabilities of the rover with an emphasis on drive planning, robotic arm operation, instrument operations, sample caching activities, and documentation of key events during entry, descent, and landing (EDL). There are a total of 16 cameras in the
Perseverance
engineering imaging system, including 9 cameras for surface operations and 7 cameras for EDL documentation. There are 3 types of cameras designed for surface operations: Navigation cameras (Navcams, quantity 2), Hazard Avoidance Cameras (Hazcams, quantity 6), and Cachecam (quantity 1). The Navcams will acquire color stereo images of the surface with a
96
∘
×
73
∘
field of view at 0.33 mrad/pixel. The Hazcams will acquire color stereo images of the surface with a
136
∘
×
102
∘
at 0.46 mrad/pixel. The Cachecam, a new camera type, will acquire images of Martian material inside the sample tubes during caching operations at a spatial scale of 12.5 microns/pixel. There are 5 types of EDL documentation cameras: The Parachute Uplook Cameras (PUCs, quantity 3), the Descent stage Downlook Camera (DDC, quantity 1), the Rover Uplook Camera (RUC, quantity 1), the Rover Descent Camera (RDC, quantity 1), and the Lander Vision System (LVS) Camera (LCAM, quantity 1). The PUCs are mounted on the parachute support structure and will acquire video of the parachute deployment event as part of a system to characterize parachute performance. The DDC is attached to the descent stage and pointed downward, it will characterize vehicle dynamics by capturing video of the rover as it descends from the skycrane. The rover-mounted RUC, attached to the rover and looking upward, will capture similar video of the skycrane from the vantage point of the rover and will also acquire video of the descent stage flyaway event. The RDC, attached to the rover and looking downward, will document plume dynamics by imaging the Martian surface before, during, and after rover touchdown. The LCAM, mounted to the bottom of the rover chassis and pointed downward, will acquire
90
∘
×
90
∘
FOV images during the parachute descent phase of EDL as input to an onboard map localization by the Lander Vision System (LVS). The rover also carries a microphone, mounted externally on the rover chassis, to capture acoustic signatures during and after EDL. The
Perseverance
rover launched from Earth on July 30th, 2020, and touchdown on Mars is scheduled for February 18th, 2021.
The Terminal Tracking Camera system (TTCam) on the NASA
Lucy
Trojan asteroid Discovery mission consists of a pair of block redundant cameras and their associated electronics that are mounted on the ...spacecraft’s Instrument Pointing Platform and co-boresighted with the rest of the mission’s science payload instruments. The primary function of the TTCams is as a navigation system designed to provide an autonomous onboard late pre-encounter update of the location of each asteroid flyby target relative to the spacecraft. However, once the terminal tracking function is complete, the TTCam system will also provide 11.0°×8.2° field of view broadband (425-675 nm) images during the close approach phase of each asteroid flyby that will be used for scientific analyses like shape modeling and assessment of each target’s geology and topography. This paper provides an overview of the TTCam cameras and electronics, the science-focused requirements that the system is designed to meet, pointers to pre-flight calibration and in-flight calibration details for the cameras, as well as a high-level summary of the kinds of science that these images will enable for the mission.
Mastcam-Z is a multispectral, stereoscopic imaging investigation on the Mars 2020 mission’s
Perseverance
rover. Mastcam-Z consists of a pair of focusable, 4:1 zoomable cameras that provide broadband ...red/green/blue and narrowband 400-1000 nm color imaging with fields of view from 25.6° × 19.2° (26 mm focal length at 283 μrad/pixel) to 6.2° × 4.6° (110 mm focal length at 67.4 μrad/pixel). The cameras can resolve (≥ 5 pixels) ∼0.7 mm features at 2 m and ∼3.3 cm features at 100 m distance. Mastcam-Z shares significant heritage with the Mastcam instruments on the Mars Science Laboratory
Curiosity
rover. Each Mastcam-Z camera consists of zoom, focus, and filter wheel mechanisms and a 1648 × 1214 pixel charge-coupled device detector and electronics. The two Mastcam-Z cameras are mounted with a 24.4 cm stereo baseline and 2.3° total toe-in on a camera plate ∼2 m above the surface on the rover’s Remote Sensing Mast, which provides azimuth and elevation actuation. A separate digital electronics assembly inside the rover provides power, data processing and storage, and the interface to the rover computer. Primary and secondary Mastcam-Z calibration targets mounted on the rover top deck enable tactical reflectance calibration. Mastcam-Z multispectral, stereo, and panoramic images will be used to provide detailed morphology, topography, and geologic context along the rover’s traverse; constrain mineralogic, photometric, and physical properties of surface materials; monitor and characterize atmospheric and astronomical phenomena; and document the rover’s sample extraction and caching locations. Mastcam-Z images will also provide key engineering information to support sample selection and other rover driving and tool/instrument operations decisions.
NASA’s OSIRIS-REx asteroid sample return mission spacecraft includes the Touch And Go Camera System (TAGCAMS) three camera-head instrument. The purpose of TAGCAMS is to provide imagery during the ...mission to facilitate navigation to the target asteroid, confirm acquisition of the asteroid sample, and document asteroid sample stowage. The cameras were designed and constructed by Malin Space Science Systems (MSSS) based on requirements developed by Lockheed Martin and NASA. All three of the cameras are mounted to the spacecraft nadir deck and provide images in the visible part of the spectrum, 400–700 nm. Two of the TAGCAMS cameras, NavCam 1 and NavCam 2, serve as fully redundant navigation cameras to support optical navigation and natural feature tracking. Their boresights are aligned in the nadir direction with small angular offsets for operational convenience. The third TAGCAMS camera, StowCam, provides imagery to assist with and confirm proper stowage of the asteroid sample. Its boresight is pointed at the OSIRIS-REx sample return capsule located on the spacecraft deck. All three cameras have at their heart a
2592
×
1944
pixel
complementary metal oxide semiconductor (CMOS) detector array that provides up to 12-bit pixel depth. All cameras also share the same lens design and a camera field of view of roughly
44
∘
×
32
∘
with a pixel scale of 0.28 mrad/pixel. The StowCam lens is focused to image features on the spacecraft deck, while both NavCam lens focus positions are optimized for imaging at infinity. A brief description of the TAGCAMS instrument and how it is used to support critical OSIRIS-REx operations is provided.
IMPORTANCE From January 1, 2003, through December 31, 2010, drug overdose deaths in Tennessee increased from 422 to 1059 per year. More of these deaths involved prescription opioids than heroin and ...cocaine combined. OBJECTIVE To assess the contribution of certain opioid-prescribing patterns to the risk of overdose death. DESIGN, SETTING, AND PARTICIPANTS We performed a matched case-control study that analyzed opioid prescription data from the Tennessee Controlled Substances Monitoring Program (TNCSMP) from January 1, 2007, through December 31, 2011, to identify risk factors associated with opioid-related overdose deaths from January 1, 2009, through December 31, 2010. Case patients were ascertained from death certificate data. Age- and sex-matched controls were randomly selected from among live patients in the TNCSMP. MAIN OUTCOMES AND MEASURES We defined a high-risk number of prescribers or pharmacies as 4 or more per year and high-risk dosage as a daily mean of more than 100 morphine milligram equivalents (MMEs) per year. The main outcome was opioid-related overdose death. RESULTS From January 1, 2007, through December 31, 2011, one-third of the population of Tennessee filled an opioid prescription each year, and opioid prescription rates increased from 108.3 to 142.5 per 100 population per year. Among all patients in Tennessee prescribed opioids during 2011, 7.6% used more than 4 prescribers, 2.5% used more than 4 pharmacies, and 2.8% had a mean daily dosage greater than 100 MMEs. Increased risk of opioid-related overdose death was associated with 4 or more prescribers (adjusted odds ratio aOR, 6.5; 95% CI, 5.1-8.5), 4 or more pharmacies (aOR, 6.0; 95% CI, 4.4-8.3), and more than 100 MMEs (aOR, 11.2; 95% CI, 8.3-15.1). Persons with 1 or more risk factor accounted for 55% of all overdose deaths. CONCLUSIONS AND RELEVANCE High-risk use of prescription opioids is frequent and increasing in Tennessee and is associated with increased overdose mortality. Use of prescription drug–monitoring program data to direct risk-reduction measures to the types of patients overrepresented among overdose deaths might reduce mortality associated with opioid abuse.
In most human populations, the ability to digest lactose contained in milk usually disappears in childhood, but in European-derived populations, lactase activity frequently persists into adulthood ...(Scrimshaw and Murray
1988). It has been suggested (Cavalli-Sforza
1973; Hollox et al.
2001; Enattah et al.
2002; Poulter et al.
2003) that a selective advantage based on additional nutrition from dairy explains these genetically determined population differences (Simoons
1970; Kretchmer
1971; Scrimshaw and Murray
1988; Enattah et al.
2002), but formal population-genetics–based evidence of selection has not yet been provided. To assess the population-genetics evidence for selection, we typed 101 single-nucleotide polymorphisms covering 3.2 Mb around the lactase gene. In northern European–derived populations, two alleles that are tightly associated with lactase persistence (Enattah et al.
2002) uniquely mark a common (∼77%) haplotype that extends largely undisrupted for >1 Mb. We provide two new lines of genetic evidence that this long, common haplotype arose rapidly due to recent selection: (1) by use of the traditional
F
ST measure and a novel test based on
p
excess, we demonstrate large frequency differences among populations for the persistence-associated markers and for flanking markers throughout the haplotype, and (2) we show that the haplotype is unusually long, given its high frequency—a hallmark of recent selection. We estimate that strong selection occurred within the past 5,000–10,000 years, consistent with an advantage to lactase persistence in the setting of dairy farming; the signals of selection we observe are among the strongest yet seen for any gene in the genome.
It is generally assumed that the internal stress distribution in foods under high pressure processing (HPP) is uniform, which may not be true for solid foods with hard inclusions, like meats with ...bones or for particulate foods. Our objective was to simulate the internal stress distribution during HPP of a model heterogeneous solid food made with a gel and a wood inclusion and determine how mechanical properties affect the internal stress distribution. It was determined that hydrostatic pressure decreased and shear stress was generated at the interface between the soft solid and the hard inclusion. The differences in pressure and shear stresses increased as the shear modulus of the soft solid increased. Our studies suggest that a better understanding of the mechanical properties that affect the development of the internal stress field is needed, since they could affect the achieved microbial inactivation levels at different locations in HPP solid foods.
Display omitted
•Stress gradients can develop inside a solid food with hard inclusions during HPP.•This contradicting the current assumption that pressure is uniform.•The gradients are dependent on the mechanical properties of the material.•Stress non-uniformity could lead to non-uniformity in microbial inactivation.
A multimetric benthic index of biotic integrity (B-IBI) was developed using data from five Chesapeake Bay sampling programs conducted between 1972 and 1991. Attributes of the index were selected by ...comparing the response of 17 candidate measures of benthic condition (metrics) between a set of minimally affected reference sites and at all other sites for which data were available. This procedure was conducted independently for each of seven habitats defined by salinity and substrate. Fifteen of the 17 candidate metrics differed significantly between reference sites and other sites for at least one habitat. No metric differed significantly in all seven habitats; however, four metrics, species diversity, abundance, biomass, and percent of abundance as pollution-indicative taxa, differed in six habitats. The index was calculated by scoring each selected metric as 5, 3, or 1 depending on whether its value at a site approximated, deviated slightly from, or deviated greatly from conditions at the best reference sites. Validation based on independent data collected between 1992 and 1994 indicated that the index correctly distinguished stressed sites from reference sites 93% of the time, with the highest validation rates occurring in high salinity habitats.
PDF
