Evaluation of serum gamma-glutamyltransferase activity as a predictor of passive transfer status in crias

OBJECTIVE: To determine the relationship between serum gamma-glutamyltransferase (GGT) activity and serum IgG concentration in neonatal crias. DESIGN: Prospective observational study. ANIMALS: 21 llama and 4 alpaca crias from 0 to 5 days old. PROCEDURE: Serum GGT activity was measured, using a commercially available kit. Serum IgG concentration was determined by use of radial immunodiffusion. With a serum IgG concentration of 1,000 mg/dl (considered adequate passive transfer), specificity and sensitivity of serum GGT activity in the detection of failure of passive transfer were determined. Regression models were developed to determine the relationship between serum GGT activity and serum IgG concentration. RESULTS: Sensitivity ranged from 0.56 to 0.89, and specificity ranged from 0.88 to 0.31, depending on the value of serum GGT activity chosen as a threshold. Proportion of crias correctly classified ranged from 0.76 to 0.52. Regression models failed to demonstrate a significant relationship between serum GGT activity and serum IgG concentration. CLINICAL IMPLICATIONS: Passive transfer status in crias cannot be accurately predicted on the basis of serum GGT activity.     

Coupling and comparing a spatially- and temporally-detailed eutrophication model with an ecosystem network model: An initial application to Chesapeake Bay

Coastal waters are modeled for a variety of purposes including eutrophication remediation and fisheries management. Combining these two approaches provides insights which are not available from either approach independently. Coupling is confounded, however, by differences in model formulations and “currencies.” We present here an initial coupling of a spatially- and temporally-detailed eutrophication model, CE-QUAL-ICM, with a network fisheries model, Ecopath. We list commonalities between the models and present algorithms and software for the exchange of information. The models are applied to the central portion of Chesapeake Bay for a contemporary summer period. After comparison of the representations of Chesapeake Bay by the two models, an illustrative example one-way, off-line, coupling is presented. In an initial examination of a 20% increase in predation on phytoplankton by a small, highly-exploited fish (Atlantic menhaden, Brevoortia tyrannus), computed reduction in phytoplankton biomass is accompanied by increased production due to enhanced nutrient recycling. Minimal impact on the structure of the food web or on biomass of higher-trophic level organisms is computed. The algorithms and software can be adapted to alternate eutrophication models and Ecopath applications and provide the first, necessary, steps for subsequent coupling with the time-variable Ecosim model.     

Enhanced sintering and functional properties of PZT thick films processed using local infrared irradiation

Significantly enhanced functional properties have been observed in lead zirconate titanate thick films when sintered for 1 min using focussed infrared irritation from a halogen bulb. By scanning the heat affected zone similar enhancements in properties were obtained when scan speeds of between 0.06 and 0.16 mm/s were used. Scanning at slower speeds resulted in incomplete sintering while sintering at higher speeds resulted in a degradation of properties. Where enhancements in properties were observed relative permittivity was increased from between 200 and 300 to 600 and 700. Piezoelectric properties (d ₃₃) were observed to increase from 20–30 pC/N to between 60 and 80 pC/N. The enhancement in properties were attributed to the improved densification and grain growth brought about by the high ramp rates and short sintering times achievable using focussed IR irradiation and the ability of the surrounding film to accommodate the sintering strains. Combining multiple scan lines in a rastering pattern failed to yield similar improvements in properties due to effects of stopping and restarting the sintering process in the scan overlap regions and the inability of the film to accommodate the sintering strains across large areas.     

The elastic buckling behaviour of a multi-celled panel under almost pure bending

Observations on the elastic buckling behaviour of a riveted thin-walled three-celled panel under almost pure bending are compared with the output from an efficient finite strip microcomputer program. Results from some preliminary studies using simple channel sections and a box section are also given. The agreement was found to be excellent for the simple sections but only fair for the more complex panel. The possible reasons for this are discussed.     

Analysis of Pseudo-Reliability of a Combat Tank System and its Optimal Design

The effectiveness of an actual combat tank system is analyzed. A measure of effectiveness (called pseudo-reliability) which is the reliability of a system weighted by the relative-performance is introduced. It appears to be a more practical measure of the system effectiveness than reliability whenever the level of performance is of primary concern as is the case for the combat tank system. A model is used to optimize the design of the system in which the system pseudo-reliability is maximized subject to a cost constraint. This model involves nonlinear programming and is solved by the sequential unconstrained minimization technique (SUMT). A numerical example with actual data from the test evaluation of five combat tanks illustrates the model.     

The preparation of very flat surfaces of silicon by electropolishing

Slices of silicon can be very successfully polished by anodic dissolution in a cell using a horizontal rotating disk as cathode, a viscous electrolyte, and a very small anode-cathode spacing (e.g. 150 μ). The surfaces of n-type material of resistivity > 0·05 Ω-cm must be illuminated during polishing, necessitating perforation of the disk to admit a beam of light to them. The optimum cell voltage is always above that for which the differential conductance of the cell is negative, and is usually about 10 V. The dissolution of 50 μ from a surface initially lapped or mechanically polished leaves it very flat and free of all work damage; electron micrographs show the residual local departures from flatness to be <0·01 μ. Material so prepared offers advantages in planar technology and as substrates for epitaxial growth. A full quantitative understanding of the mechanisms involved is still lacking however.     

Biomass cofiring at Seward Station

Sithe Energies, under a cooperative agreement with EPRI, the US Department of Energy, the Biomass Interest Group (BIG) and the Upgraded Coal Interest Group (UCIG), has developed a demonstration of cofiring biomass with pulverized coal at the Seward Generating Station on Boiler #12. This demonstration, constructed and tested by Foster Wheeler Development Corporation (FWDC) included construction of a facility to receive, screen, store and transport sawdust into a front-fired pulverized coal boiler. This facility has several distinctive features including the sawdust receiving system, the silo storage for processed biomass, and the injection system using the centerpipe of the coal burners. The biomass is prepared separately and transported separately from the coal. The wood waste is then injected into the center of the coal flame and burned there for optimum biofuel performance.

This demonstration, involving an extended period of cofiring testing, is based upon successful parametric tests conducted in December, 1996 and July, 1997. These tests documented the impact of cofiring, in the short term, on capacity, efficiency and emissions. Those results are now being evaluated over a long-term period. Additionally, operational and maintenance issues are being addressed with this demonstration and modifications have been made to improve the handling of the fuel. This paper describes the cofiring system, and reviews progress to date with the combustion tests.     

Assessment of plant-available phosphate in limed,acid soils using several soil-testing procedures

A range of soil-testing procedures was used in a factorial glasshouse study to assess the plant-available phosphate (P) status of soils which had been treated with lime and added P. A close 1:1 relationship (r = 0.90^***) was obtained between plant P uptake and resin-extractable soil P. In contrast, Olsen-, Colwell-, Bray (I) and (II)-, and Mehlich-extractable P were only weakly correlated with P uptake. Inclusion of 4 different indices of P-buffer capacity did not improve the relationship between plant P uptake, and extractable P. The difficulty in relating plant P uptake data to extractable-soil P levels is attributed to the problems associated with extracting P from limed soils. There was no useful relationship between plant P uptake and isotopically-exchangeable P in the soils.     

Regulation of enzymatic activity involved in sex pheromone production in the housefly, Musca domestica

Ovarian produced ecdysteroids regulate sex pheromone production in the female housefly, inducing the synthesis of (Z)-9-tricosene (Z9-23:Hy), cis-9,10-epoxytricosane, (Z)-14-tricosen-10-one and methylalkanes. Experiments were performed to gain a detailed understanding of the processes affected by 20-hydroxyecdysone (20-HE) that result in sex pheromone production as the female becomes reproductively mature. A novel microsomal fatty acid synthetase (FAS) is present in the epidermal tissue and plays a role in producing the methyl-branched fatty acid precursors to the methylalkanes. This FAS is released from the microsomes in the presence of 3 M KCl. A major enzyme activity influenced by 20-HE is the fatty acyl-CoA elongation system. A shift in the chain length specificity of the products of the elongation system causes the change in the chain lengths of the alkenes produced to switch from C27 and longer in the previtellogenic female to C23 in the mature female. Data is presented indicating that it is the condensation activity of the elongation system that is affected. Z9-23:Hy arises from a 24 carbon acyl group which is reduced to an aldehyde, and then converted to the hydrocarbon. Data is presented demonstrating that it is the fatty acyl-CoA derivative and not the free fatty acid that is the substrate. There does not appear to be a chain length specificity which regulates the conversion of fatty acyl-CoAs to hydrocarbons as both 24 and 28 carbon fatty acyl-CoAs are converted to hydrocarbon by both males and females of all ages.     

Review of Madhouse and The Lobotomist.

Reviews the books, Madhouse: A Tragic Tale of Megalomania and Modern Medicine by Andrew Scull (see record 2005-06776-000); and The Lobotomist: A Maverick Medical Genius and His Tragic Quest to Rid the World of Mental Illness by Jack El-Hai (see record 2005-02343-000). In both books, the history of experimental clinical psychiatry is laid bare with devastating accounts of the efforts to conquer mental illness by any means necessary. Both books are fascinating reading and may illuminate our current context in which the biological avenues for treating mental disorders continue to traffic in hopes of a one-size-fits-all cure, while psychoanalysis ambivalently struggles with how to conduct rigorous research to demonstrate the efficacy of our treatment. Andrew Scull's book Madhouse offers a well-documented historical account of a bizarre episode in American psychiatric history. The centerpiece of Scull's investigative work is Henry Cotton, MD, the superintendent of the Trenton State Hospital in Trenton, New Jersey, from 1907-1930. Once Cotton arrived at Trenton, he was appalled by the conditions he found and instituted reforms such as eliminating the culture of violence by attendants, removing over 700 pieces of restraining equipment from the hospital, and introducing occupational therapy. Jack El-Hai gives us the next segment of psychiatric surgery in his book The Lobotomist, a biography of the neurologist, turned surgical outlaw, Walter Freeman, MD. Walter Freeman was a neurologist fascinated with science and experimentation. Settling into work at St. Elizabeth's hospital in Washington, DC, in 1924, Freeman eventually joined the faculty of George Washington University where he remained until 1954. At that time neurosyphilis was the scourge of mental hospitals producing thousands of victims who were totally disabled by the neurological sequellae of tertiary illness. Thus lobotomy became an efficient outpatient procedure that could be applied to a larger patient population. Both of these books are important reading. Of all the great medical advances of the last century, surely the one that stands out as perhaps the greatest is the Nuremberg Code of 1947, which requires a competent patient giving informed consent to treatment and to research efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)