Method for separating biological cells

A method for separating biological cells by suspending a mixed cell population in a two-phase polymer system is described. The polymer system consists of droplet phases with different surface potentials for which the cell populations exhibit different affinities. The system is subjected to an electrostatic field of sufficient intensity to cause migration of the droplets with an attendant separation of cells

Standard arc welders provide high amperage direct current source

Standard arc welders or power supplies are hooked up in parallel or series connections to obtain an adequate supply of current or voltage for various purposes. This method provides maximum flexibility in a wide range of voltages and currents

SPAR project: Counter current distribution of biologicals

Preliminary ground based experiments strongly support the validity of a proposed space experiment in the separation of biological cells by counter current distribution (CCD). It was shown that a low level applied selective field can accelerate the separation of the phases by a very large factor. An electric field therefore should be very effective in space in lieu of gravity for the phase separation step. This appears to solve a central problem in implementing CCD in space and opens the technique to many types of large cell mixtures for which it has not been applicable before due to rapid settling effects. It was determined that electrophoretic migration of the cells, as a possibly disturbing factor, will be of negligible effect. Attenuation of a light beam by scattering generated a signal indicating the course of the phase separation

Countercurrent distribution of biological cells

A neutral polymer phase system consisting of 7.5 percent dextran 40/4.5 percent PEG 6, 0.11 M Na phosphate, 5 percent fetal bovine serum (FBS), pH 7.5, was developed which has a high phase droplet electrophoretic mobility and retains cell viability over many hours. In this and related systems, the drop mobility was a linear function of drop size, at least in the range 4-30 micron diameter. Applications of and electric field of 4.5 v/cm to a system containing 10 percent v/v bottom phase cleared the system more than two orders of magnitude faster than in the absence of the field. At higher bottom phase concentrations a secondary phenomenon intervened in the field driven separations which resulted in an increase in turbidity after clearing had commenced. The increase was associated with a dilution of the phase system in the chamber. The effect depended on the presence of the electric field. It may be due to electroosmotic flow of buffer through the Amicon membranes into the sample chamber and flow of phase system out into the rinse stream. Strategies to eliminate this problem are proposed

Systematic Review of Physiotherapy during Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD)

In COPD patients, acute exacerbations are important events. Reviews of studies investigating treatment during AECOPD focus on medical management, with little discussion of physiotherapy. Therefore a systematic review was undertaken of the studies pertaining to physiotherapy during AECOPD. Methods: Studies were identified by searching databases and scanning reference lists. Appropriate studies were reviewed by two independent investigators. Data were extracted using a standardized form. Where possible, a score was assigned using the PEDro scale for assessment of study quality. HIll, K., Patman, S., & Brooks, D. (2008). Systematic review of physiotherapy during Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD). American Journal of Respiratory and Critical Care Medicine, 177, Abstracts Issue, A137. ISSN: 1073-449

Continuously operating induction plasma accelerator Patent

Continuous operation, single phased, induction plasma accelerator producing supersonic speed

The Future of Particle Physics

After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.Comment: Invited talk given at the International Conference on Fundamental Sciences: Mathematics and Theoretical Physics, Singapore, 13-17 March 200

Is systematic downside beta risk really priced? Evidence in emerging market data

Several studies advocating safety first as a major concern to investors propose downside beta risk as an alternative to the traditional systematic risk-beta. Downside measures are concerned with a subset of the data and therefore the results in the studies that consider the downside beta only may be biased. This study addresses this issue by including downside co-skewness risk in addition to the downside beta risk in the pricing model. In a sample of 27 emerging markets two-stage rolling regression analysis fails to support pricing models with downside risk measures. In a cross-sectional analysis inclusion of downside co-skewness improves model fit. When considered together, downside beta is potential and downside co-skewness is a risk to the rational investor. Even though our results are inconclusive the evidence strongly suggests a need for further investigation of co-skewness risk in pricing models that adopt a downside risk framework.Beta, Downside risk, Emerging markets

Analysis of polarizability measurements made with atom interferometry

We present revised measurements of the static electric dipole polarizabilities of K, Rb, and Cs based on atom interferometer experiments presented in [Phys. Rev. A 2015, 92, 052513] but now re-analyzed with new calibrations for the magnitude and geometry of the applied electric field gradient. The resulting polarizability values did not change, but the uncertainties were significantly reduced. Then we interpret several measurements of alkali metal atomic polarizabilities in terms of atomic oscillator strengths $f_{ik}$, Einstein coefficients $A_{ik}$, state lifetimes $\tau_{k}$, transition dipole matrix elements $D_{ik}$, line strengths $S_{ik}$, and van der Waals $C_6$ coefficients. Finally, we combine atom interferometer measurements of polarizabilities with independent measurements of lifetimes and $C_6$ values in order to quantify the residual contribution to polarizability due to all atomic transitions other than the principal $ns$-$np_J$ transitions for alkali metal atoms.Comment: 23 pages, 9 figures, 6 table

Study of ephemeris accuracy of the minor planets

The current state of minor planet ephemerides was assessed, and the means for providing and updating these emphemerides for use by both the mission planner and the astronomer were developed. A system of obtaining data for all the numbered minor planets was planned, and computer programs for its initial mechanization were developed. The computer based system furnishes the osculating elements for all of the numbered minor planets at an adopted date of October 10, 1972, and at every 400 day interval over the years of interest. It also furnishes the perturbations in the rectangular coordinates relative to the osculating elements at every 4 day interval. Another computer program was designed and developed to integrate the perturbed motion of a group of 50 minor planets simultaneously. Sampled data resulting from the operation of the computer based systems are presented