Bidirectional outflows as evidence of magnetic reconnection leading to a solar microflare

Magnetic reconnection is a rapid energy release process that is believed to be responsible for flares on the Sun and stars. Nevertheless, such flare-related reconnection is mostly detected to occur in the corona, while there have been few studies concerning the reconnection in the chromosphere or photosphere. Here we present both spectroscopic and imaging observations of magnetic reconnection in the chromosphere leading to a microflare. During the flare peak time, chromospheric line profiles show significant blueshifted/redshifted components on the two sides of the flaring site, corresponding to upflows and downflows with velocities of $\pm$(70--80) km s$^{-1}$, comparable with the local Alfv\'{e}n speed as expected by the reconnection in the chromosphere. The three-dimensional nonlinear force-free field configuration further discloses twisted field lines (a flux rope) at a low altitude, cospatial with the dark threads in He I 10830 \r{A} images. The instability of the flux rope may initiate the flare-related reconnection. These observations provide clear evidence of magnetic reconnection in the chromosphere and show the similar mechanisms of a microflare to those of major flares.Comment: 16 pages, 5 figures, accepted for publication in ApJ

Morphea-like localized involutional lipoatrophy—a case report associated with family history

AbstractLocalized involutional lipoatrophy is a rare, sporadic disease with female tendency and characterized by focal loss of adipose tissue. We report two sisters, aged 8 years and 6 years, who developed asymptomatic depressive areas on the upper left arm and upper right arm, respectively. Cutaneous sonography showed slight thickening of the dermis and remarkably decreased thickness of the cutaneous fat tissue. Histopathology of a biopsy specimen from the elder sister revealed an increase in homogenized collagen bundles and entrapment of eccrine glands high in the dermis, as well as small to medium-sized lipocytes with a scarcity of inflammatory cells

Immunization with a single extracellular enveloped virus protein produced in bacteria provides partial protection from a lethal orthopoxvirus infection in a natural host

AbstractSubunit vaccines that use the vaccinia virus extracellular envelope protein A33R alone or combined with other structural proteins are excellent candidates for a new smallpox vaccine. Since a new smallpox vaccine would be used in humans, who are the natural hosts for the Orthopoxvirus variola, the agent of smallpox, it would be important to determine whether a prospective smallpox vaccine can protect from a lethal Orthopoxvirus infection in a natural host. We addressed this question using the mouse-specific Orthopoxvirus ectromelia virus. We demonstrate that immunization with recombinant ectromelia virus envelope protein EVM135 or its ortholog vaccinia virus A33R produced in E. coli protects susceptible mice from a lethal ectromelia virus infection. This is the first report that a subunit vaccine can provide protection to a lethal Orthopoxvirus infection in its natural host

Subnanometer-resolution structures of the grass carp reovirus core and virion.

Grass carp reovirus (GCRV) is a member of the Aquareovirus genus of the family Reoviridae, a large family of double-stranded RNA (dsRNA) viruses infecting plants, insects, fishes and mammals. We report the first subnanometer-resolution three-dimensional structures of both GCRV core and virion by cryoelectron microscopy. These structures have allowed the delineation of interactions among the over 1000 molecules in this enormous macromolecular machine and a detailed comparison with other dsRNA viruses at the secondary-structure level. The GCRV core structure shows that the inner proteins have strong structural similarities with those of orthoreoviruses even at the level of secondary-structure elements, indicating that the structures involved in viral dsRNA interaction and transcription are highly conserved. In contrast, the level of similarity in structures decreases in the proteins situated in the outer layers of the virion. The proteins involved in host recognition and attachment exhibit the least similarities to other members of Reoviridae. Furthermore, in GCRV, the RNA-translocating turrets are in an open state and lack a counterpart for the sigma1 protein situated on top of the close turrets observed in mammalian orthoreovirus. Interestingly, the distribution and the organization of GCRV core proteins resemble those of the cytoplasmic polyhedrosis virus, a cypovirus and the structurally simplest member of the Reoviridae family. Our results suggest that GCRV occupies a unique structure niche between the simpler cypoviruses and the considerably more complex mammalian orthoreovirus, thus providing an important model for understanding the structural and functional conservation and diversity of this enormous family of dsRNA viruses