The impact and recovery of asteroid 2018 LA.

The June 2, 2018, impact of asteroid 2018 LA over Botswana is only the second asteroid detected in space prior to impacting over land. Here, we report on the successful recovery of meteorites. Additional astrometric data refine the approach orbit and define the spin period and shape of the asteroid. Video observations of the fireball constrain the asteroid's position in its orbit and were used to triangulate the location of the fireball's main flare over the Central Kalahari Game Reserve. 23 meteorites were recovered. A consortium study of eight of these classifies Motopi Pan as a HED polymict breccia derived from howardite, cumulate and basaltic eucrite, and diogenite lithologies. Before impact, 2018 LA was a solid rock of ~156 cm diameter with high bulk density ~2.85 g/cm3, a relatively low albedo pv ~ 0.25, no significant opposition effect on the asteroid brightness, and an impact kinetic energy of ~0.2 kt. The orbit of 2018 LA is consistent with an origin at Vesta (or its Vestoids) and delivery into an Earth-impacting orbit via the v6 resonance. The impact that ejected 2018 LA in an orbit towards Earth occurred 22.8 ± 3.8 Ma ago. Zircons record a concordant U-Pb age of 4563 ± 11 Ma and a consistent 207Pb/206Pb age of 4563 ± 6 Ma. A much younger Pb-Pb phosphate resetting age of 4234 ± 41 Ma was found. From this impact chronology, we discuss what is the possible source crater of Motopi Pan and the age of Vesta's Veneneia impact basin.

Retrospective analyses of heartworm (Dirofilaria immitis) disease and ectoparasite preventive medication compliance in veterinary practices in the USA.

BACKGROUND: Compliance failure with administration of heartworm (HW) disease preventives has been reported as the main contributor to HW disease incidence in medicalized dogs. This study aimed to evaluate purchase compliance with different canine HW preventive products in the USA. METHODS: Anonymized transaction data from clinics throughout the USA served as the basis for two retrospective analyses. We first examined the monthly equivalent doses of HW preventive purchases from clinics that had implemented extended-release moxidectin injectables ProHeart® 6 (PH6) and/or ProHeart® 12 (PH12) compared to clinics that prescribed monthly HW preventatives (MHWP) only. In the second analysis, the purchase compliance in practices that dispensed only flea and tick (FT) and HW products separately but did not dispense combination products (dual-therapy practices) was compared to the purchase compliance with the combination product Simparica Trio® (sarolaner, moxidectin, and pyrantel chewable tablets), purchased in clinics having implemented combination therapy in their formulary (combination-therapy practices). In both analyses, the numbers of monthly doses dispensed annually per dog were calculated. RESULTS: Transaction data from 3,539,990 dogs in 4615 practices were included in the first analysis. In dogs administered PH12 or PH6, the numbers of monthly equivalent doses were 12 and 8.1, respectively. In both clinic types, the average annual number of MHWP doses totaled 7.3. In the second analysis, a total of 919 practices were identified as combination-therapy practices and 434 as dual-therapy-only practices. A total of 246,654 dogs (160,854 dogs in dual-therapy practices and 85,800 dogs in combination-therapy practices) were included in the calculation of the average annual number of monthly doses, which totaled 6.8 (HW preventive products) and 4.4 (FT products) in dual-therapy practices compared to 7.2 months for both FT and HW preventives with Simparica Trio® across both practice types. CONCLUSIONS: The injectable HW preventive PH12 is the only product that provides 12 months of heartworm disease prevention in a single veterinarian-administered injection. When choosing a monthly preventive, the combination therapy was associated with a greater purchase compliance compared with FT and HW products being dispensed separately.

The compliance and revenue benefits of ProHeart Vs monthly heartworm disease preventives in the US.

The aim of the current study was to understand how the canine heartworm disease preventive ProHeart® 12 (extended-release injectable moxidectin, PH 12), impacts heartworm preventive purchase compliance and veterinary practice revenue over time compared to monthly heartworm disease preventives. This was a preliminary observational purchase compliance and revenue study based on a retrospective review of transaction data from 4,615 general practices across the United States. The review period was from September 2018 to August 2020. Anonymous transaction records of over 13 million canine patients were analyzed. Of these, only 3.5 million (25.7%) patients purchased any heartworm preventive, as has been presented in other studies. Practices that implemented PH 12 demonstrated the most growth in canine heartworm prevention revenue, patients, and patient compliance levels during the 12-month observation period, compared to previous year. These practices saw year over year growth in percent patients receiving heartworm protection, as well as 10% and 15% growth in the proportion of preventive patients compliant for more than 6 months and 12 months respectively. In contrast, practices that did not bring on PH 12 and only dispensed monthly heartworm preventives saw a decline in the proportion of canine preventive patients that were compliant for more than 6 months. Similarly, PH 12 practices experienced 15% growth in preventive revenue, and practices that did not bring on PH 12 only experienced 3.9% growth in preventive revenue. PH 12 was single-handedly responsible for all growth in patients compliant for more than 6 months in this study. Growth in protection of canine patients with PH 12 proves a helpful tool where mitigation strategies have thus far failed to curb increasing canine heartworm disease prevalence in the US.

On laboratory simulation and the effect of small temperature oscillations about the freezing point and ice formation on the evaporation rate of water on Mars.

We report measurements of the evaporation rate of water under Mars-like conditions (CO2 atmosphere at 7 mbar and approximately 0 degrees C) in which small temperature oscillations about the freezing point repeatedly formed and removed a thin layer of ice. We found that the average evaporation at 2.7 +/- 0.5 degrees C without an ice layer (corrected for the difference in gravity on Earth and on Mars) was 1.24 +/- 0.12 mm/h, while at -2.1 +/- 0.3 degrees C with an ice layer the average evaporation rate was 0.84 +/- 0.08 mm/h. These values are in good agreement with those calculated for the evaporation of liquid water and ice when it is assumed that evaporation only depends on diffusion and buoyancy. Our findings suggest that such differences in evaporation rates are entirely due to the temperature difference and that the ice layer has little effect on evaporation rate. We infer that the formation of thin layers of ice on pools of water on Mars does not significantly increase the stability of water on the surface of Mars.

Ocular motor signatures of cognitive dysfunction in multiple sclerosis.

The anatomical and functional overlap between ocular motor command circuitry and the higher-order networks that form the scaffolding for cognition makes for a compelling hypothesis that measures of ocular motility could provide a means to sensitively interrogate cognitive dysfunction in people with multiple sclerosis (MS). Such an approach may ultimately provide objective and reproducible measures of cognitive dysfunction that offer an innovative capability to refine diagnosis, improve prognostication, and more accurately codify disease burden. A further dividend may be the validation and application of biomarkers that can be used in studies aimed at identifying and monitoring preventative, protective and even restorative properties of novel neurotherapeutics in MS. This Review discusses the utility of ocular motor measures in patients with MS to characterize disruption to wide-ranging networks that support cognitive function.

Chelyabinsk airburst, damage assessment, meteorite recovery, and characterization.

The asteroid impact near the Russian city of Chelyabinsk on 15 February 2013 was the largest airburst on Earth since the 1908 Tunguska event, causing a natural disaster in an area with a population exceeding one million. Because it occurred in an era with modern consumer electronics, field sensors, and laboratory techniques, unprecedented measurements were made of the impact event and the meteoroid that caused it. Here, we document the account of what happened, as understood now, using comprehensive data obtained from astronomy, planetary science, geophysics, meteorology, meteoritics, and cosmochemistry and from social science surveys. A good understanding of the Chelyabinsk incident provides an opportunity to calibrate the event, with implications for the study of near-Earth objects and developing hazard mitigation strategies for planetary protection.

Radar-enabled recovery of the Sutter's Mill meteorite, a carbonaceous chondrite regolith breccia.

Doppler weather radar imaging enabled the rapid recovery of the Sutter's Mill meteorite after a rare 4-kiloton of TNT-equivalent asteroid impact over the foothills of the Sierra Nevada in northern California. The recovered meteorites survived a record high-speed entry of 28.6 kilometers per second from an orbit close to that of Jupiter-family comets (Tisserand's parameter = 2.8 ± 0.3). Sutter's Mill is a regolith breccia composed of CM (Mighei)-type carbonaceous chondrite and highly reduced xenolithic materials. It exhibits considerable diversity of mineralogy, petrography, and isotope and organic chemistry, resulting from a complex formation history of the parent body surface. That diversity is quickly masked by alteration once in the terrestrial environment but will need to be considered when samples returned by missions to C-class asteroids are interpreted.