10 research outputs found
The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids
The Sariçiçek howardite meteorite shower consisting of 343 documented stones
occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic
isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during
~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid
was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS
dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages
for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and
the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic
and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic
studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic
observations and analysis of organic material indicate a small portion of carbonaceous chondrite
material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on
soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW,
fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the
first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data
indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of
asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of
meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family
asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4
m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia
impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of
Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was
formed ~22 Ma ago
CHEMICAL CONTENT OF THE DIDIM AND KEMER METEORITES.
82nd Annual Meeting of the Meteoritical-Society (MetSoc) -- JUL 07-12, 2019 -- Sapporo, JAPAN -- Meteorit Soc[Abstract Not Available]WOS:00047211360034
Determination of changes in heavy metal accumulation depending on plant species, plant organism, and traffic density in some landscape plants
The level of pollution has reached the dimensions that threaten human health, with the rapid urbanization and the increase of energy consumption especially in developing countries. Every year in the world, millions of people lose their lives because of air pollution. Heavy metals have a separate precaution in pollutants, especially in terms of human health, because they can remain intact in nature for long periods of time, they tend to bioaccumulate and some are toxic or carcinogenic even at low concentrations. Therefore, monitoring of heavy metal pollution and determination of risky areas is very important. Biomonitors are the most commonly used methods for monitoring heavy metal pollution. However, determining which plants and organelles are more suitable for monitoring the metal is essential in order to ensure that the monitoring is reliable. In this study, it was aimed to determine the variations of the concentration of Ni, Pb, and Cd elements depending on the traffic density in leaves, seeds, and branches of Ailanthus altissima, Biota orientalis, Platanus orientalis, and Pyracantha coccinea which are grown in areas with heavy, low dense, and non-traffic areas. As a result of the study, it was determined that concentrations of Ni, Pb, and Cd increased depending on traffic density. According to the results obtained, it was determined that seeds and branches of Biota orientalis were the most suitable species and organelles to determine Ni pollution. The leaves of Ailanthus altissima are very suitable for monitoring the pollution of Pb and Cd. © 2018, Springer Nature B.V
Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly
For more than 100 years, the fruit fly Drosophila melanogaster has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula Drosophilae , that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type–related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the Drosophila community and serves as a reference to study genetic perturbations and disease models at single-cell resolution