CD56 is a pathogen recognition receptor on human natural killer cells

Aspergillus (A.) fumigatus is an opportunistic fungal mold inducing invasive aspergillosis (IA) in immunocompromised patients. Although antifungal activity of human natural killer (NK) cells was shown in previous studies, the underlying cellular mechanisms and pathogen recognition receptors (PRRs) are still unknown. Using flow cytometry we were able to show that the fluorescence positivity of the surface receptor CD56 significantly decreased upon fungal contact. To visualize the interaction site of NK cells and A. fumigatus we used SEM, CLSM and dSTORM techniques, which clearly demonstrated that NK cells directly interact with A. fumigatus via CD56 and that CD56 is re-organized and accumulated at this interaction site time-dependently. The inhibition of the cytoskeleton showed that the receptor re-organization was an active process dependent on actin re-arrangements. Furthermore, we could show that CD56 plays a role in the fungus mediated NK cell activation, since blocking of CD56 surface receptor reduced fungal mediated NK cell activation and reduced cytokine secretion. These results confirmed the direct interaction of NK cells and A. fumigatus, leading to the conclusion that CD56 is a pathogen recognition receptor. These findings give new insights into the functional role of CD56 in the pathogen recognition during the innate immune response

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

A.C.L. Railway Station, Orlando, Fla. The City Beautiful.

Color postcard of A.C.L. Railway Station, Orlando, Fla. depicting genre scene of people waiting to board a train.https://stars.library.ucf.edu/cfm-images/6031/thumbnail.jp

A.C.L. Railway Station, Orlando, Fla. The City Beautiful.

Color postcard of A.C.L. Railway Station, Orlando, Fla. depicting genre scene of people waiting to board a train.https://stars.library.ucf.edu/cfm-images/6032/thumbnail.jp

Cypress Methuselah.

Color tone photographic postcard of the Cypress Methuselah in Longwood, Fla. Text on back of postcard: The big Cypress tree is located near Longwood, Fla. midway between Orlando and Sanford. It is said to be the largest tree east of California. It is 47 feet in circumfrance at its base, and is 127 feet in height. It is also supposed to be the oldest tree in the U.S.A. The estimated age being between 2,000 and 3,000 years.https://stars.library.ucf.edu/cfm-images/2886/thumbnail.jp

Cypress Methuselah.

Color tone photographic postcard of the Cypress Methuselah in Longwood, Fla. Text on back of postcard: The big Cypress tree is located near Longwood, Fla. midway between Orlando and Sanford. It is said to be the largest tree east of California. It is 47 feet in circumfrance at its base, and is 127 feet in height. It is also supposed to be the oldest tree in the U.S.A. The estimated age being between 2,000 and 3,000 years.https://stars.library.ucf.edu/cfm-images/2887/thumbnail.jp