Ionic charge distributions of energetic particles from solar flares

The effects which solar flare X-rays have on the charge states of solar cosmic rays is determined quantitatively. Rather than to characterize the charge distribution by temperature alone, it is proposed that the X-ray flux at the acceleration site also is used. The effects of flare X-rays are modeled mathematically

A search for outflows from X-ray bright points in coronal holes

Properties of X-ray bright points using two of the instruments on Solar Maximum Mission were investigated. The mass outflows from magnetic regions were modeled using a two dimensional MHD code. It was concluded that mass can be detected from X-ray bright points provided that the magnetic topology is favorable

MHD‐driven kinetic dissipation in the solar wind and corona

Mechanisms for the deposition of heat in the lower coronal plasma are discussed, emphasizing recent attempts to reconcile the fluid and kinetic perspectives. Structures at magnetohydrodynamic (MHD) scales may drive a nonlinear cascade, preferentially exciting high perpendicular wavenumber fluctuations. Relevant dissipative kinetic processes must be identified that can absorb the associated energy flux. The relationship between the MHD cascade and direct cyclotron absorption, including cyclotron sweep, is discussed. We conclude that for coronal and solar wind parameters the perpendicular cascade cannot be neglected and may be more rapid than cyclotron sweep. Solar wind observational evidence suggests the relevance of the ion inertial scale, which is associated with current sheet thickness during reconnection. We conclude that a significant fraction of dissipation in the corona and solar wind likely proceeds through a perpendicular cascade and small-scale reconnection, coupled to kinetic processes that act at oblique wavevectors

HUMAN SPINAL CORD IMPEDANCE: ITS APPLICATION IN NEUROSURGICAL STEREOTAXIC CORDOTOMY

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72600/1/j.1749-6632.1970.tb17740.x.pd

Are Child's Class C Patients With Acute Variceal Bleeding Worth Treating?

In the ten year period January 1980 to December 1989, 102 patients with Child’s Class C liver disease (Pugh's Modification) were admitted with acute variceal bleeding to one surgical unit with a policy of early sclerotherapy. There were 56 males and 46 females; the average age was 55 years (range 28–77). Fifty-three suffered from alcoholic cirrhosis. Four died before definitive treatment could be carried out, three from liver failure and one from uncontrolled bleeding. Of the remaining 98 patients, eight had urgent oesophageal transection with three deaths from hepatorenal failure; 90 had sclerotherapy with 19 hospital deaths, nine from recurrent bleeding, eight from liver failure often coupled with renal failure and two from respiratory complications. Of the 76 who survived to leave hospital, 52 received chronic injection sclerotherapy, 10 had elective oesophageal transection and 14 did not have further elective intervention for various reasons. Surviving patients have been followed up at a special Liver Clinic with minimum follow up of one year. Although no patient has yet survived ten years, the one, five and eight year survivals of 50%, 21% and 13% suggest that salvage of thdse patients is worthwhile

Mapping warm molecular hydrogen with Spitzer's Infrared Array Camera (IRAC)

Photometric maps, obtained with Spitzer's Infrared Array Camera (IRAC), can provide a valuable probe of warm molecular hydrogen within the interstellar medium. IRAC maps of the supernova remnant IC443, extracted from the Spitzer archive, are strikingly similar to spectral line maps of the H2 pure rotational transitions that we obtained with the Infrared Spectrograph (IRS) instrument on Spitzer. IRS spectroscopy indicates that IRAC Bands 3 and 4 are indeed dominated by the H2 v=0-0 S(5) and S(7) transitions, respectively. Modeling of the H2 excitation suggests that Bands 1 and 2 are dominated by H2 v=1-0 O(5) and v=0-0 S(9). Large maps of the H2 emission in IC433, obtained with IRAC, show band ratios that are inconsistent with the presence of gas at a single temperature. The relative strengths of IRAC Bands 2, 3, and 4 are consistent with pure H2 emission from shocked material with a power-law distribution of gas temperatures. CO vibrational emissions do not contribute significantly to the observed Band 2 intensity. Assuming that the column density of H2 at temperatures T to T+dT is proportional to T raised to the power -b for temperatures up to 4000 K, we obtained a typical estimate of 4.5 for b. The power-law index, b, shows variations over the range 3 to 6 within the set of different sight-lines probed by the maps, with the majority of sight-lines showing b in the range 4 to 5. The observed power-law index is consistent with the predictions of simple models for paraboloidal bow shocks.Comment: 27 pages, including 11 figures. Accepted for publication in Ap

Socioeconomic inequalities in early adulthood disrupt the immune transcriptomic landscape via upstream regulators

Disparities in socio-economic status (SES) predict many immune system-related diseases, and previous research documents relationships between SES and the immune cell transcriptome. Drawing on a bioinformatically-informed network approach, we situate these findings in a broader molecular framework by examining the upstream regulators of SES-associated transcriptional alterations. Data come from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a nationally representative sample of 4543 adults in the United States. Results reveal a network—of differentially expressed genes, transcription factors, and protein neighbors of transcription factors—that shows widespread SES-related dysregulation of the immune system. Mediational models suggest that body mass index (BMI) plays a key role in accounting for many of these associations. Overall, the results reveal the central role of upstream regulators in socioeconomic differences in the molecular basis of immunity, which propagate to increase risk of chronic health conditions in later-life

Coronal heating distribution due to low-frequency wave-driven turbulence

The heating of the lower solar corona is examined using numerical simulations and theoretical models of magnetohydrodynamic turbulence in open magnetic regions. A turbulent energy cascade to small length scales perpendicular to the mean magnetic field can be sustained by driving with low-frequency Alfven waves reflected from mean density and magnetic field gradients. This mechanism deposits energy efficiently in the lower corona, and we show that the spatial distribution of the heating is determined by the mean density through the Alfven speed profile. This provides a robust heating mechanism that can explain observed high coronal temperatures and accounts for the significant heating (per unit volume) distribution below two solar radius needed in models of the origin of the solar wind. The obtained heating per unit mass on the other hand is much more extended indicating that the heating on a per particle basis persists throughout all the lower coronal region considered here.Comment: 19 pages, 5 figures. Accepted for publication in Ap