Period Increase and Amplitude Distribution of Kink Oscillation of Coronal Loop

Coronal loops exist ubiquitously in the solar atmosphere. These loops puzzle astronomers over half a century. Solar magneto-seismology (SMS) provides a unique way to constrain the physical parameters of coronal loops. Here, we study the evolution of oscillations of a coronal loop observed by the Atmospheric Imaging Assembly (AIA). We measure geometric and physical parameters of the loop oscillations. In particular, we find that the mean period of the oscillations increased from 1048 to 1264 s during three oscillatory cycles. We employ the differential emission measure method and apply the tools of SMS. The evolution of densities inside and outside the loop is analyzed. We found that an increase of density inside the loop and decrease of the magnetic field strength along the loop are the main reasons for the increase in the period during the oscillations. Besides, we also found that the amplitude profile of the loop is different from a profile would it be a homogeneous loop. It is proposed that the distribution of magnetic strength along the loop rather than density stratification is responsible for this deviation. The variation in period and distribution of amplitude provide, in terms of SMS, a new and unprecedented insight into coronal loop diagnostics

High Levels of IgA Antibodies to Helicobacter Pylori among Omani Women during Pregnancy and after Delivery

Background: Helicobacter pylori (H. pylori), is a common infection in pregnant women accompanied by variations in the levels of the IgM, IgA and IgG antibody isotypes. The variations of anti-H. pylori antibodies during and after pregnancy, and the extent of protection they provide to the mother and the fetus are not completely understood. Objectives: To investigate the changes of the anti-H. pylori IgM, IgA and IgG levels in healthy Omani pregnant women during pregnancy and 3 months after delivery. Methods: Serum samples obtained from 70 Omani healthy pregnant women, with no history of autoimmune diseases, were tested for anti-H. pylori IgM, IgA and IgG in the first trimester of pregnancy and 3 months after delivery. In parallel and as a control group, sera obtained from a group of 70 healthy non-pregnant Omani women were tested. The levels of anti-H. pylori IgM, IgA and IgG were measured using standard Enzyme Linked Immunosorbent Assays (ELISAs). Results: Anti-H. pylori IgA levels were found to be significantly higher during pregnancy (p=0.046) and after delivery (p=0.02) when compared to the control group. Moreover, a significant increase in the levels of anti-H. pylori IgM, IgA and IgG was detected after delivery (p=0.002) when compared to the levels during pregnancy. Conclusion: Pregnancy is associated with an increase in the levels of anti-H. pylori IgA antibodies. In addition, anti-H. pylori IgM, IgG and IgA antibody levels increase after delivery