Chorus source region localization in the Earth's outer magnetosphere using THEMIS measurements

Discrete ELF/VLF chorus emissions, the most intense electromagnetic plasma waves observed in the Earth's radiation belts and outer magnetosphere, are thought to propagate roughly along magnetic field lines from a localized source region near the magnetic equator towards the magnetic poles. THEMIS project Electric Field Instrument (EFI) and Search Coil Magnetometer (SCM) measurements were used to determine the spatial scale of the chorus source localization region on the day side of the Earth's outer magnetosphere. We present simultaneous observations of the same chorus elements registered onboard several THEMIS spacecraft in 2007 when all the spacecraft were in the same orbit. Discrete chorus elements were observed at 0.15–0.25 of the local electron gyrofrequency, which is typical for the outer magnetosphere. We evaluated the Poynting flux and wave vector distribution and obtained chorus wave packet quasi-parallel propagation to the local magnetic field. Amplitude and phase correlation data analysis allowed us to estimate the characteristic spatial correlation scale transverse to the local magnetic field to be in the 2800–3200 km range

What works best for ensuring treatment adherence. Lessons from a social support program for people treated for tuberculosis in Ukraine

Background Worldwide, TB is one of the top 10 causes of death and the leading cause from a single infectious agent. Ukraine is one of 30 countries with the highest burden of multidrug-resistant tuberculosis. Global literature shows that social support (SS) is important in improving TB treatment adherence, reducing lost to follow up rates and improving treatment outcomes. There are several models of SS available, and the literature provides little information on what aspects of SS are most important to TB patients in improving their adherence. Methods We used qualitative data collected through in-depth interviews (IDI) with 21 TB patients and 15 SS providers and coordinators in Ukraine in August-September 2016 to understand how the SS program promoted treatment adherence among patients. We examined the aspects of outpatient TB treatment that made adherence particularly difficult for patients in at-risk groups and aspects of the SS programs that worked best for addressing those barriers. Interviews were transcribed and analysis was performed to derive emergent themes. Results Main barriers included side effects from medicine, the amount of time required daily for transportation and waiting in lines at the health facility, transportation expenses, risks of being identified when visiting a TB facility and lack of motivation to seek treatment. Features of the SS program most valued by patients were convenience of not having to visit facility and support provided by nurses. These two features directly addressed most of the barriers identified. The commitment and qualities of the nurses that provided the SS was an important element of the program. Conclusions This qualitative study suggests that the SS program in Ukraine was successful in reducing treatment default among patients at high risk of default because it directly addressed most of the major barriers they faced to treatment adherence

Chorus wave-normal statistics in the Earth's radiation belts from ray tracing technique

Discrete ELF/VLF (Extremely Low Frequency/Very Low Frequency) chorus emissions are one of the most intense electromagnetic plasma waves observed in radiation belts and in the outer terrestrial magnetosphere. These waves play a crucial role in the dynamics of radiation belts, and are responsible for the loss and the acceleration of energetic electrons. The objective of our study is to reconstruct the realistic distribution of chorus wave-normals in radiation belts for all magnetic latitudes. To achieve this aim, the data from the electric and magnetic field measurements onboard Cluster satellite are used to determine the wave-vector distribution of the chorus signal around the equator region. Then the propagation of such a wave packet is modeled using three-dimensional ray tracing technique, which employs K. Rönnmark's WHAMP to solve hot plasma dispersion relation along the wave packet trajectory. The observed chorus wave distributions close to waves source are first fitted to form the initial conditions which then propagate numerically through the inner magnetosphere in the frame of the WKB approximation. Ray tracing technique allows one to reconstruct wave packet properties (electric and magnetic fields, width of the wave packet in k-space, etc.) along the propagation path. The calculations show the spatial spreading of the signal energy due to propagation in the inhomogeneous and anisotropic magnetized plasma. Comparison of wave-normal distribution obtained from ray tracing technique with Cluster observations up to 40° latitude demonstrates the reliability of our approach and applied numerical schemes

Динаміка мікрофлори пародонтальних кишень у хворих на остеоартроз при прогресуванні генералізованого пародонтиту

The article presents data on the qualitative and quantitative composition of the microflora of periodontal pockets of patients who suffered from initial-I, II, II-III degrees severity of generalized periodontitis with concomitant osteoartrhitis.У статті представлено дані про якісний та кількісний склад мікрофлори пародонтальних кишень хворих на генералізований пародонтит початкового–І, ІІ, ІІ–ІІІ ступенів тяжкості з супутім остеоартрозом

Spin canting and lattice symmetry in La2_2CuO4_4

While the dominant magnetic interaction in La$_2$CuO$_4$ is superexchange between nearest-neighbor Cu moments, the pinning of the spin direction depends on weak anisotropic effects associated with spin-orbit coupling. The symmetry of the octahedral tilt pattern allows an out-of-plane canting of the Cu spins, which is compensated by an opposite canting in nearest-neighbor layers. A strong magnetic field applied perpendicular to the planes can alter the spin canting pattern to induce a weak ferromagnetic phase. In light of recent evidence that the lattice symmetry is lower than originally assumed, we take a new look at the nature of the field-induced spin-rotation transition. Comparing low-temperature neutron diffraction intensities for several magnetic Bragg peaks measured in fields of 0 and 14 T, we find that a better fit is provided by a model in which spins in neighboring layers counter-rotate in plane, resulting in a noncollinear configuration. This model allows a consistent relationship between lattice symmetry and spin orientation at all Cu sites.Comment: 7 pages, 4 figure

Magnetic excitations in coupled Haldane spin chains near the quantum critical point

Two quasi-1-dimensional S=1 quantum antiferromagnetic materials, PbNi2V2O8 and SrNi2V2O8, are studied by inelastic neutron scattering on powder samples. While magnetic interactions in the two systems are found to be very similar, subtle differences in inter-chain interaction strengths and magnetic anisotropy are detected. The latter are shown to be responsible for qualitatively different ground state properties: magnetic long-range order in SrNi2V2O8 and disordered ``spin liquid'' Haldane-gap state in PbNi2V2O8.Comment: 15 figures, Figs. 5,9, and 10 in color. Some figures in JPEG format. Complete PostScript and PDF available from http://papillon.phy.bnl.gov/publicat.ht