Magnetic Field Amplification Associated with the Richtmyer-Meshkov Instability

The amplification of a magnetic field due to the Richtmyer-Meshkov instability (RMI) is investigated by two-dimensional MHD simulations. Single-mode analysis is adopted to reveal definite relation between the nonlinear evolution of RMI and the field enhancement. It is found that an ambient magnetic field is stretched by fluid motions associated with the RMI, and the strength is amplified significantly by more than two orders of magnitude. The saturation level of the field is determined by a balance between the amplified magnetic pressure and the thermal pressure after shock passage. This effective amplification can be achieved in a wide range of the conditions for the RMI such as the Mach number of an incident shock and the density ratio at a contact discontinuity. The results suggest that the RMI could be a robust mechanism of the amplification of interstellar magnetic fields and cause the origin of localized strong fields observed at the shock of supernova remnants.Comment: 16 pages, 9 figures, accepted for publication in Ap

Comparison of RMI 3 and RMI 4 in pre-operative evaluation of ovarian masses

Background: To differentiate ovarian mass as benign or malignant could change clinical approach. Finding a screening and diagnostic method for ovarian cancer is challenging due to high mortality and insidious symptoms. Risk malignancy index (RMI) has the advantage of rapid and exact triage of patients with ovarian mass.Methods: Prospective study carried for 2 years at NRI Medical College and General Hospital, Chinakakani, Mangalagiri, Andhra Pradesh, India. 79 patients with ovarian mass were investigated and risk malignancy index (RMI-3 and RMI-4) calculated. Final confirmation was done based on histopathological report. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for RMI 3 and RMI 4 taking histopathology as control and comparison was done.Results: (n=79); 50 (63.29%) cases were benign and 29 (36.70%) were malignant based on histopathology. RMI 4 is more sensitive (68.96%) than RMI 3 (62.06%), but RMI 3 is more specific (94%) than RMI 4 (92%).The positive predictive value of RMI-3 and RMI-4 were 85.71%  and 83.33% respectively. The negative predictive value for RMI-4 and RMI-3 were 83.63% and 81.03% respectively.Conclusions: With increasing age, chance of malignancy increases. RMI 4 was more sensitive than RMI-3, however less specific than RMI 3 in differentiating benign and malignant tumors. The positive predictive value is slightly more for RMI 3, than RMI 4. Negative predictive value is slightly more for RMI 4, than RMI 3.

Study of the turbulent mixing zone induced by the Richtmyer-Meshkov instability using Laser Doppler Velocimetry and Schlieren visualizations

An experimental study of the compressible mixing generated by the Richtmyer-Meshkov instability (RMI) is carried out in a vertical shock tube by means of two-components Laser Doppler Velocimetry (2C-LDV) measurements and Time-resolved Schlieren visualizations. An attempt is made to quantify the RMI-induced air/sulphurhexafluoride (SF6) mixing by measuring turbulence levels inside the mixing zone at a given stage of its development and by extracting the growth rate of the mixing zone from the Schlieren images

Comparison of risk of malignancy indices in the preoperative evaluation of adnexal masses

Background: An adnexal mass patient is a common cause of hospital admission. The differentiation between malignant and benign cases is an important step in the management of such patients. The risk of malignancy index (RMI) is a simple scoring system depend on ultrasound data, menopausal status and serum concentrations of CA-125 tumor marker and has a great value in differentiation between benign and malignant adnexal masses. 4 different types of risk of malignancy index are created. The objective of the study was to compare the diagnostic performance of the four malignancy risk indices in differentiating benign and malignant ovarian tumors.Methods: This prospective study was performed on 60 patients with an adnexal mass confirmed on vaginal ultrasound.Results: There was statistical significance difference between the 4 types of RMI in benign and malignant groups. RMI 1, RMI 2, and RMI 3 had nearly the same area under the ROC curve; however, at the cut-off of>58.41, RMI 3 was more sensitive and less specific than RMI 1 or RMI 2. The RMI 2 was the most specific in predicting malignancy in terms of area under the curve; however, there was no statistically significant difference in performance of RMI 2 and 4 in malignant group.Conclusions: RMI 1, RMI 2, and RMI 3 had nearly the same area under the ROC curve; however, at the cut-off of >58.41, RMI 3 was more sensitive and less specific than RMI 1 or RMI 2, on the other hand the most specific was RMI 2 more than the other 3 RMIs

The French ?Earned Income Supplement? (RSA) and back-to-work incentives

RMI, API, unemployment, means-tested benefits, back-to-work incentives.

Unhealthy Eating Habits in the Marshall Islands Result from Deteriorating Reef Systems

Small Island nations such as the Marshall Islands (RMI) have limited resources. In order to provide food to its population of about 60,000, the Marshallese have had to replace traditional food with foreign imports. A result of this is the prevalence of obesity and non-communicable diseases (NCDs). The most common NCD is diabetes. Diabetic patients are encouraged to follow strict diets that include mostly traditional, local food such as fish; however, because of environmental factors, fish populations are threatened. The objective of this study was to understand the relationship between healthy reefs, healthy fish populations and the health of communities as a result of high fish consumption and the consumption of imported canned goods. Our methods included consumption surveys from a 2010 report (Marshall Islands Marine Resources Authority – Coastal Fisheries Division), interviews acquired from 10 households per village, information on health and population (RMI Census & RMI Annual Health Report), and data collection from bio sampling done on outer island reef fish. Our preliminary results indicate that families who consume more fish are less likely to have a diabetic member. In conclusion, individuals who consume fish as their main source of protein are overall healthier and less susceptible to diseases like diabetes