Glyco-biomarkers: Potential determinants of cellular physiology and pathology

Once dismissed as just the icing on the cake, sugar molecules are emerging as vital components in life’s intricate machinery. Our understanding of their function within the context of the proteins and lipids to which they are attached has matured rapidly, and with it the far reaching clinical implications are becoming understood. Recent advances in high-throughput glycomic techniques, glyco biomarker profiling, glyco-bioinformatics and development of increasingly sophisticated glyco-arrays, combined with our increased understanding of the molecular details of glycosylation have facilitated the linkage between aberrant glycosylation and human diseases, and highlighted the possibility of using glyco-biomarkers as potential determinants of disease and its progression. The focus of this review is to give an insight into the biological significance of these glycomodifications, highlight some specific examples of glyco-biomarkers in relation to autoimmunity and in particular rheumatoid arthritis, and to explore the exciting possibility of exploiting these for diagnostic and prognostic strategies

The interaction of the solar wind with the interstellar medium

The expected characteristics of the solar wind, extrapolated from the vicinity of the earth are described. Several models are examined for the interaction of the solar wind with the interstellar plasma and magnetic field. Various aspects of the penetration of neutral interstellar gas into the solar wind are considered. The dynamic effects of the neutral gas on the solar wind are described. Problems associated with the interaction of cosmic rays with the solar wind are discussed

Large scale solar modulation of 500 MeV/N galactic cosmic rays seen from 1-30 AU

Using measurements of cosmic rays obtained by Cerenkov counters on Pioneer 10 and Pioneer 11 and neutron monitor data from Earth, the spatial and temperal development of cosmic ray modulation during the last solar maximum were observed. The large-scale features of modulation and recovery are similar at these three sites and thus appear rotationally symmetric near the ecliptic plane. Outward propagating features characterize the radial dependence. The decline of the old cosmic ray cycle is marked by steplike decreases that propagate outward at nearly the solar wind velocity. During the start of the new cosmic ray cycle, recovery occurs first in the inner heliosphere and, after a lag comparable with that of the declining phase, appears later farther out. However, the direction of diffusive propagation is still inward, because the gradient remains positive. Forbush decreases are common at all three sites, and are evidently of great importance in understanding modulation. The largest decrease occurred during a short series of events in the summer of 1982 and had half the amplitude of the eleven year cycle

A standard for a graph representation for functional programs

The data structures used in the authors' functional language graph reduction implementations are described, together with a standard notation for representing the graphs in a textual format. The graphs employed are compatible with FLIC and with the functional languages in use at Birmingham and Warwick. The textual format is designed to be transmittable easily across networks

Time and energy dependence of the cosmic ray gradient in the outer heliosphere

Pioneers 10 and 11, now 35 and 18 AU from the Sun, continue to extend our knowledge of the spatial dependence of cosmic ray intensities in the heliosphere. Radial gradients measured from these spacecraft by UCSD detectors which have integral energy responses above thresholds of 80 and 500 MeV/nucleon are reported. An average gradient of 2%/AU typifies the data set as a whole, but there are time and energy dependences that deviate from this value. With operating lifetimes of 13 and 12 years, respectively, for the two spacecraft, the time dependence was followed for over a solar cycle. The higher energy channel shows less modulation on all time scales. At the start of the present cycle, the gradient is lower than the average value during the last solar cycle

LM rendezvous procedures - F mission, AS-505/CSM-106/LM-4 Final report

Rendezvous procedures for LM-4 and CSM for use in crew training and flight plannin

Direct Simulations of Particle Acceleration in Fluctuating Electromagnetic Field across a Shock

We simulate the acceleration processes of collisionless particles in a shock structure with magnetohydrodynamical (MHD) fluctuations. The electromagnetic field is represented as a sum of MHD shock solution (\Mag_0, \Ele_0) and torsional Alfven modes spectra (\delta \Mag, \delta \Ele ). We represent fluctuation modes in logarithmic wavenumber space. Since the electromagnetic fields are represented analytically, our simulations can easily cover as large as eight orders of magnitude in resonant frequency, and do not suffer from spatial limitations of box size or grid spacing. We deterministically calculate the particle trajectories under the Lorenz force for time interval of up to ten years, with a time step of $\sim 0.5 \sec$. This is sufficient to resolve Larmor frequencies without a stochastic treatment. Simulations show that the efficiency of the first order Fermi acceleration can be parametrized by the fluctuation amplitude $\eta \equiv ^{\frac 1 2} {B_0}^{-1}$ . Convergence of the numerical results is shown by increasing the number of wave modes in Fourier space while fixing $\eta$. Efficiency of the first order Fermi acceleration has a maximum at $\eta \simeq 10^1$. The acceleration rate depends on the angle between the shock normal and \Mag_0, and is highest when the angle is zero. Our method will provide a convenient tool for comparing collisionless turbulence theories with, for example, observations of bipolar structure of super nova remnants (SNRs) and shell-like synchrotron-radiating structure.Comment: 11 pages, 4 figures, accepted for publication in The Astrophysical Journal letter

Radial gradients and anisotropies of cosmic rays in the interplanetary medium

Radial gradients and anisotropies of cosmic rays in interplanetary mediu

Modern theory of Fermi acceleration: a new challenge to plasma physics

One of the main features of astrophysical shocks is their ability to accelerate particles to extremely high energies. The leading acceleration mechanism, the diffusive shock acceleration is reviewed. It is demonstrated that its efficiency critically depends on the injection of thermal plasma into acceleration which takes place at the subshock of the collisionless shock structure that, in turn, can be significantly smoothed by energetic particles. Furthermore, their inhomogeneous distribution provides free energy for MHD turbulence regulating the subshock strength and injection rate. Moreover, the MHD turbulence confines particles to the shock front controlling their maximum energy and bootstrapping acceleration. Therefore, the study of the MHD turbulence in a compressive plasma flow near a shock is a key to understanding of the entire process. The calculation of the injection rate became part of the collisionless shock theory. It is argued that the further progress in diffusive shock acceleration theory is impossible without a significant advance in these two areas of plasma physics.Comment: 12 pages, 4 figures, invited talk at APS/ICPP, Quebec 2000, to appear in Phys. of Plasma

Development of a Force-Based Ream Vector Measurement System For Glenoid Reaming Simulation

Glenoid reaming is a technically challenging step during total shoulder arthroplasty surgery that may be improved through frequent practice and exposure to simulation training. At our institution, a vibration haptic glenoid reaming simulator is being developed that simulates the vibrations felt during glenoid reaming. This thesis presents the development of a force-based reamer vector measurement system that allows the simulator to measure the user’s net applied force and reamer angle of approach. This capability allows for the simulation of eccentric reaming maneuvers commonly used to adjust the glenoid orientation. The system error was characterized and evaluated using a robot to operate a surgical reaming tool. Finally, a study was performed that assessed the ability of surgeons to correct glenoid retroversion while using the haptic vibration simulator. Overall, the surgeons were able to correct glenoid orientation within 1 degree of the target orientation, according to the simulator’s reaming vector measurement system