Optical tweezer for probing erythrocyte membrane deformability

We report that the average rotation speed of optically trapped crenated erythrocytes is direct signature of their membrane deformability. When placed in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The deformation of cells brings in chirality and asymmetry in shape that make them rotate under the scattering force of a linearly polarized optical trap. A change in the deformability of the erythrocytes, due to any internal or environmental factor, affects the rotation speed of the trapped crenated cells. Here we show how the increment in erythrocyte membrane rigidity with adsorption of $Ca^{++}$ ions can be exhibited through this approach.Comment: Published in Appl. Phys. Lett. 95, 233703 (2009); Two supplementary multimedia files are available at the journal page: http://link.aip.org/mm/APPLAB/1.3272269/083949aplv1.mov and http://link.aip.org/mm/APPLAB/1.3272269/083949aplv2.mo

ECONOMICS OF HEIFER RAISING OPTIONS

As dairy farms grow and specialize in milking cows, one enterprise that may be removed from the dairy farm to allow for milk cow herd expansion is heifer raising. Custom heifer raising is increasingly common across the country and purchasing heifers may be preferred to raising heifers. However, these alternatives are not suitable for all dairy farmers. In this article, we examine heifer enterprise costs relative to using a custom raiser or purchasing heifers. We identify factors that should be considered in making the proper decision relative to the heifer enterprise.Livestock Production/Industries,

PROFITABILITY AND PRODUCTION EFFICIENCY OF THE CROP AND LIVESTOCK ENTERPRISES OF MICHIGAN DAIRY OPERATIONS: 1998 SUMMARY AND ANALYSIS

This paper summarizes the 1998 results of the Dairy Profitability and Production Efficiency project. Among the major findings are that the average cost of production was almost exactly equal to the average milk herd revenue on a per hundredweight basis. All eight farms covered variable costs of producing milk. Five of the eight farms showed a profit when all costs of production were included. All six farms that raised their own replacement heifers lost money on the enterprise. With respect to crop production, corn and corn silage were not profitable enterprises. The hay enterprise was profitable for five of the farms.Productivity Analysis,

USING A MULTIPLE PRODUCT AND MULTIPLE INPUT APPROACH TO DAIRY PROFIT MAXIMIZATION: A SIMULATION USING OPERATIONS RESEARCH METHODS

Dairy producers generally take a single output/multiple input approach when making production decisions. Under component pricing, with large variance in individual component prices, a multiple output/multiple input approach maximizes profits. This paper applied our approach to the individual farm milk production decision.Livestock Production/Industries, Productivity Analysis,

Market Segments and Farmer Preferences for Financial Record Systems

farm management, accounting systems, Farm Management,

Uplink Analysis of Large MU-MIMO Systems With Space-Constrained Arrays in Ricean Fading

Closed-form approximations to the expected per-terminal signal-to-interference-plus-noise-ratio (SINR) and ergodic sum spectral efficiency of a large multiuser multiple-input multiple-output system are presented. Our analysis assumes correlated Ricean fading with maximum ratio combining on the uplink, where the base station (BS) is equipped with a uniform linear array (ULA) with physical size restrictions. Unlike previous studies, our model caters for the presence of unequal correlation matrices and unequal Rice factors for each terminal. As the number of BS antennas grows without bound, with a finite number of terminals, we derive the limiting expected per-terminal SINR and ergodic sum spectral efficiency of the system. Our findings suggest that with restrictions on the size of the ULA, the expected SINR saturates with increasing operating signal-to-noise-ratio (SNR) and BS antennas. Whilst unequal correlation matrices result in higher performance, the presence of strong line-of-sight (LoS) has an opposite effect. Our analysis accommodates changes in system dimensions, SNR, LoS levels, spatial correlation levels and variations in fixed physical spacings of the BS array.Comment: 7 pages, 3 figures, accepted for publication in the proceedings of IEEE ICC, to be held in Paris, France, May 201