The recent U.S. trade deficit - no cause for panic

International trade ; Balance of trade

Oil imports and the fall of the dollar

Petroleum industry and trade ; Money supply

Crystallographic Analyses of Ion Channels: Lessons and Challenges

Membrane proteins fascinate at many levels, from their central functional roles in transport, energy transduction, and signal transduction processes to structural questions concerning how they fold and operate in the exotic environments of the membrane bilayer and the water-bilayer interface and to methodological issues associated with studying membrane proteins either in situ or extracted from the membrane. This interplay is beautifully exemplified by ion channels, a collection of integral membrane proteins that mediate the transmembrane passage of ions down their electrochemical potential gradient (for general reviews, see Refs. 1 and 2). Ion channels are key elements of signaling and sensing pathways, including nerve cell conduction, hormone response, and mechanosensation. The characteristic properties of ion channels reflect their conductance, ion selectivity, and gating. Ion channels are often specific for a particular type of ion (such as potassium or chloride) or a class of ions (such as anions) and are typically regulated by conformational switching of the protein structure between "open" and "closed" states. This conformational switching may be gated in response to changes in membrane potential, ligand binding, or application of mechanical forces. Detailed functional characterizations of channels and their gating mechanisms have been achieved, reflecting exquisite methodological advances such as patch clamp methods that can monitor the activities of individual channels (3). Until recently, corresponding information about the three-dimensional structures of channels was not available, reflecting difficulties in obtaining sufficient quantities of membrane proteins for crystallization trials. Happily, this situation has started to change with the structure determinations of the Streptomyces lividans K+ channel (KcsA (4)) and the Mycobacterium tuberculosis mechanosensitive channel (MscL (5)). A variety of reviews (6-12) have appeared recently that discuss functional implications of these channel structures. This review discusses these developments from a complementary perspective, by considering the implications of these structures from within the larger framework of membrane protein structure and function. Because of space restrictions, this review necessarily emphasizes membrane proteins that are composed primarily of alpha-helical bundles, such as KcsA and MscL, rather than beta-barrel proteins, such as porins, typically found in bacterial outer membranes

Do foreigners control the U.S. money supply?

Money supply ; Investments, Foreign

A Buyer\u27s Catalogue of Prepurchase Precautions to Minimize CERCLA Liability in Commercial Real Estate Transactions

Because the cost and incidence of hazardous waste contamination are soaring and because the courts favor broad interpretations of CERCLA\u27s liability provisions, counsel for prospective purchasers of commercial real estate must take certain prepurchase precautions to minimize potential CERCLA liability. This Comment pro- vides practical suggestions as to the aim and form of those precautions. In Part II, this Comment first examines the basic statutory framework and liability scheme of CERCLA. Part III discusses the common law principles of successor liability and their relation to CERCLA\u27s liability mechanism. Finally, in Part IV, this Comment presents a variety of preventive law steps to lessen exposure to hazardous waste liability under CERCLA. Part IV begins by discussing buyers\u27 and sellers\u27 goals when negotiating a real estate purchase and the environmental risks that generally inhere in such a transaction. Part IV then demonstrates in successive subsections how to identify, evaluate, and allocate the risks of a specific purchase. This Comment provides examples of a condition, representations, and an indemnification clause, all of which may serve as protective devices in real estate contracts to allocate these risks. Part IV also considers how courts in four recent cases have responded to buyers\u27 and sellers\u27 attempts to enforce indemnity clauses to avoid CERCLA liability

DO FARM BUSINESSES AND BIG BUSINESSES APPLY DIFFERENT CAPITAL BUDGETING PROCEDURES?

Recent studies of capital budgeting procedures used by business executives suggest increasing use of present value methods. This study compares Massachusetts greenhouse business managers use of capital budgeting procedures to those of Fortune 1000 firms. Results indicate that different capital budgeting procedures are used and that the payback criterion remains the most popular for the farm firms studied. Some implications for Extension finance educators are drawn.Agribusiness,

PC-CUBE: A Personal Computer Based Hypercube

PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation

Design and Validation of an Arterial Pulse Wave Analysis Device

Student Number :9900127Y - MSc (Eng) dissertation - Faculty of Engineering and the Built EnvironmentArterial pulse wave analysis studies the wave shape of the blood pressure pulse. The pulse wave provides more information than the extreme systolic and dia- stolic pressures, measured with a cuff sphygmomanometer. The aim of the research is to investigate the design issues in a pulse wave analysis system, and to compare these to a commercially available system. The system was compared and validated by measuring the pulse wave at the radial artery (wrist) using the non-invasive technique of arterial tonometry. The design conformed to the IEC-601 safety standard to ensure patient safety. The data was compared against the data from the commercial system and analysis was performed in the time and frequency domain. The performance of the design suggests that, in some respects, the design was comparable to the commer- cial system, however, a number of performance characteristics fell short of the commercial system. Suggestions have been made to address these problems in further research