Review of \u3ci\u3eThe Big Empty: The Great Plains in the Twentieth Century\u3c/i\u3e by R. Douglas Hurt

The Big Empty: The Great Plains in the Twentieth Century endeavors to synthesize a history that is as almost as vast and challenging as the region itself. Not surprisingly, R. Douglas Hurt succeeds most fully when addressing his specialty, agricultural history. Less masterful but still effective are the book\u27s sections concerning energy development, Plains Indians, Latinos, and political economy. The Big Empty has little to say, by contrast, about shifting perceptions of the Plains, the decline of railroads, and the rise of federal highways, while Hurt\u27s insistence on the fundamental stasis of the Plains environment seems to contradict the many cases of environmental change he analyzes

Shallow sea bottom farming: Multicrop system developed at Vizhinjam

Even though marilculture technology for various organisms like mussels, pearl oysters, lobsters and crabs has been developed during the last three decades by the CMFRI and several other institutions in India, there has been considerable practical difficulties for commercialising these programmes in Indian waters due to the rough weather conditions during the two monsoon periods as well as due to the nonavailability of adequate protected bays along the Indian coasts

STEER: Beam Selection for Full-Duplex Millimeter Wave Communication Systems

Modern millimeter wave (mmWave) communication systems rely on beam alignment to deliver sufficient beamforming gain to close the link between devices. We present a novel beam selection methodology for multi-panel, full-duplex mmWave systems, which we call STEER, that delivers high beamforming gain while significantly reducing the full-duplex self-interference coupled between the transmit and receive beams. STEER does not necessitate changes to conventional beam alignment methodologies nor additional over-the-air feedback, making it compatible with existing cellular standards. Instead, STEER uses conventional beam alignment to identify the general directions beams should be steered, and then it makes use of a minimal number of self-interference measurements to jointly select transmit and receive beams that deliver high gain in these directions while coupling low self-interference. We implement STEER on an industry-grade 28 GHz phased array platform and use further simulation to show that full-duplex operation with beams selected by STEER can notably outperform both half-duplex and full-duplex operation with beams chosen via conventional beam selection. For instance, STEER can reliably reduce self-interference by more than 20 dB and improve SINR by more than 10 dB, compared to conventional beam selection. Our experimental results highlight that beam alignment can be used not only to deliver high beamforming gain in full-duplex mmWave systems but also to mitigate self-interference to levels near or below the noise floor, rendering additional self-interference cancellation unnecessary with STEER

Tube choledochoureterostomy: A simple method for bile diversion

A technique of bile diversion by tube choledochoureterostomy has been devised for the purpose of studying the role of bile in the intestinal absorption of drugs. This method was used in six dogs. No technical difficulties or major complications developed, as are inevitable with alternative methods, including external fistula. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted