A survey of bovine colostrum composition and colostrum management practices on Pennsylvania dairy farms

Colostrum composition and management were surveyed via sample and data collection from 55 dairy farms in Pennsylvania. Colostrum samples were analyzed for fat, protein, lactose, total solids, ash, Ig, lactoferrin, water- and fat-soluble vitamins, and minerals. Mean percentages of fat, protein, and lactose in colostrum were 6.7, 14.9, and 2.5, respectively. Concentrations of IgG₁, IgG₂, IgA, IgM, and lactoferrin were 35.0, 6.0, 1.7, 4.3, and 0.8 mg/mL, respectively. Mean concentrations of fat-soluble vitamins, including retinol, tocopherol, and β-carotene, were 4.9, 2.9, and 0.7 μg/g, respectively. Mean concentrations of water-soluble vitamins were 0.34, 0.90, 4.55, 0.60, 0.15, 0.21, and 0.04 μg/mL for niacin, thiamine, riboflavin, vitamin B₁₂, pyridoxal, pyridoxamine, and pyridoxine, respectively. Mean concentrations (mg/kg) of selected minerals in colostrum were also determined (Ca 4,716; P 4,452; Mg 733; Na 1,058; K 2,845; Zn 38; Fe 5.3; Cu 0.3; S 2,595; and Mn 0.1). The findings of this study revealed that the mean concentrations of most nutrients in colostrum have increased when compared with values previously reported. Results also showed that management practices have improved over time, particularly with regard to colostrum storage and feeding. Additionally, we observed that herd size influenced colostrum management and quality. It can be inferred, based on these findings, that although improvements have been made with regard to colostrum management and quality, there is still a need to educate producers on issues related to storage and timely feeding of colostrum to increase passive transfer and decrease the rate of calf morbidity and mortality.     

A Method for comprehensively Assessing Economic Trade-Offs of New Irrigation Developments

To meet the anticipated increase in global demand for food and fibre products, large areas of land around the world are being cleared and infrastructure constructed to enable irrigation, referred to herein as ‘greenfield irrigation’. One of the challenges in assessing the profitability of a greenfield irrigation development is understanding the impact of variability in climate and water availability and the trade-offs with scheme size, cost and the sensitivity of crop yield to water stress. For example, is it more profitable to irrigate a small area of land most years or a large area once every few years? And, is it more profitable to partially or fully water the crop? This paper presents a new method for efficiently linking a river system model and an agricultural production model to explore the financial trade-offs of different management choices, thereby enabling the optimal scheme area and most appropriate level of farmer risk to be identified. The method is demonstrated for a hypothetical but plausible greenfield irrigation development based around a large dam in the Flinders catchment, northern Australia. It was found that a dam and irrigation development paid for and operated by the same entity is not, under the conditions examined in this analysis, economically sustainable. The method could also be used to explore the impact of different management strategies on the agricultural production and profitability of existing irrigation schemes within a whole of river system context.     

Solar disinfection of contaminated water: a comparison of three small-scale reactors

This paper compares three different collector shapes for the disinfection of water heavily contaminated with Escherichia coli (K-12). Tests were carried out in real sunlight using laboratory scale reactors to determine the performance of different reflector profiles. The reactors were constructed using Pyrex tubing and aluminium reflectors of compound parabolic, parabolic and V-groove profiles. Results have shown that the compound parabolic reflector promoted a more successful inactivation of E. coli than the parabolic and V-groove profiles. Tests were also carried out to assess the improvement to disinfection which could be achieved using TiO₂ coated Pyrex rods fixed within the reactors. This technique, however, yielded a slight enhancement in the compound parabolic reactor but no benefit to overall disinfection performance in either the parabolic or V-groove reactors.These results show that the use of UV sunlight to disinfect contaminated drinking water in a full-scale continuous flow solar reactor is both promising and an appropriate technology for developing countries but that the inclusion of a fixed photocatalyst within the reactor tubes has yet to prove any significant improvement.     

Composition-structure-property (Zn and Ca ion release) evaluation of Si-Na-Ca-Zn-Ce glasses: Potential components for nerve guidance conduits

Bioactive glasses have demonstrated tailored therapeutic ion release, primarily with respect to the augmentation of hard tissues. However, controlled degradation and release of therapeutic ions from biomaterials may also play an important role in soft tissue regeneration such as repair of peripheral nerve discontinuities. In this study, three silica based glasses (0.5SiO₂-0.2CaO-0.13ZnO-XNa₂O-(0.17-X) CeO₂) where, (0.04 < X < 0.14) were synthesised and characterised. The local environment of the ²⁹Si isotope was probed for each glass using ²⁹Si MAS-NMR, whilst the thermal characteristics of each glass were examined using DTA. Following these analyses, ion release profiles for Ca²⁺ and Zn²⁺ were evaluated; an equivalent specific surface area of 1 m² of each glass powder was incubated (37 °C) in 10 ml of citric acid buffer and TRIS-HCI buffer solution (pH 3.0 and pH 7.4 respectively) for incubation periods of up to 30 days. The Zn²⁺ concentration of each filtrate was analysed using flame Atomic Absorption Spectroscopy (Varian AA240FS Fast Sequential AAS) and the Ca²⁺ concentration of each filtrate was determined using Inductively Coupled Plasma-Mass Spectrometer (Varian 820 ICP-MS). Results obtained from the ²⁹Si MAS-NMR spectra indicated Q² structures pervading the network. An analytical model was proposed to analyse the ion release profiles for each glass, and indicated heterogeneous dissolution of glass networks. The ion release data demonstrates that ion release in the range (19.26-3130 ppm) for Ca²⁺ and in the range (5.97-4904 ppm) for Zn²⁺ occurred. Release of such elements, at appropriate levels, from peripheral nerve guidance conduits may be advantageous with respect to the repair of peripheral nerve discontinuities.     

Application of the laser flash diffusivity method to thin high thermal conductivity materials

The evolution of semiconductor devices and the dramatic increases in the power dissipation per unit volume of ever smaller microelectronic devices means electronic packaging technologies must evolve to manage the dissipation of heat. One of the major issues is the development of new packaging materials optimised for heat management. Future packaging will incorporate layers with thermal diffusivities exceeding that of copper in thin, sub-millimetre foils. Metrology techniques are needed to measure the thermal diffusivity of these thin, thermally fast materials. As some new materials are developed only in the form of thin substrates the laser flash technique is limited in its application to these materials. This paper addresses the application of a nanosecond pulsed laser flash instrument to the measurement of thermal diffusivity of thin high thermal conductivity materials and the errors associated with the measurement. An experimental comparison is made with a laser flash instrument where the laser pulse is of higher energy but millisecond pulse duration. Received: 25 October 1997/Accepted: 2 January 1998     

Repeated isolation in the neonatal rat produces alterations in behavior and ventral striatal dopamine release in the juvenile after amphetamine challenge.

Rat pups were isolated from the mother and nest for 1 hr per day from Postnatal Day (PN) 2 to 9. At PN 27, rats were tested for behavioral responsiveness to 2.0 or 7.5 mg/kg amphetamine. Only isolated rats receiving the 7.5 mg/kg dose displayed increased activity scores, compared with nonisolated and nonhandled controls. Their increased activity is attributed to a slower latency to enter into stereotypy. In a second experiment, similarly treated groups were challenged by the 7.5 mg/kg dose during a session in which a microdialysis probe implanted in the ventral striatum was being perfused. The challenge drug elicited a much greater increase in dialysate dopamine in isolated vs nonisolated groups. Results are discussed with regard to dissociation between sensitized and subsensitized responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of training on general practitioners'' use of a brief intervention for excessive drinkers

During recent years the outcome of acute hepatitis A in chronic liver disease has been discussed controversially. Data from large hepatitis A epidemics and surveillance data from the United States suggest a significantly higher risk of fatal outcome in patients with chronic hepatitis B. Patients with chronic active hepatitis or liver cirrhosis seem to be at highest risk, while HBsAg carriers may exhibit a benign course of the disease. Patients with chronic hepatitis C also seem to have a significantly higher risk of fulminant hepatic failure when superinfected with hepatitis A. The recently reported unsuspected coincidence of autoimmune markers with a fulminant course of hepatitis A in those patients needs to be confirmed. Vaccination against hepatitis A in patients with chronic liver disease has been shown to be safe and effective.     

How healthy are the police? A survey of life-style factors

AIMS: To examine the prevalence of five life-style behaviours among New South Wales police. DESIGN: A cross-sectional survey using a self-administered questionnaire. SETTING AND PARTICIPANTS: A total of 852 police were recruited from metropolitan Sydney. MEASUREMENTS: Prevalence related to age and sex of self-reported alcohol consumption, cigarette smoking, inadequate exercise, perception of overweight and stress symptoms. RESULTS: A high level (89%) of participation was achieved in the survey. Almost half (48%) of males and more than two-fifths (40%) of females consumed alcohol excessively including continuous hazardous or harmful consumption and binge drinking. Excessive drinking was more prevalent among younger police. There were 8% of male and 15% of female police who reported that they did not drink alcohol. Over one-quarter (27%) of male and one-third (32%) of female respondents reported smoking. Almost half (46%) of men and women (47%) believed that they were overweight. More than one-fifth (21%) of men and less than one-quarter (24%) of women reported that they did not exercise. Finally, 12% of men and 15% of women reported feeling moderate to severe symptoms of stress. CONCLUSIONS: The police work-force offers an opportunity to screen for a large number of healthy, young and high risk individuals (particularly men) who are hard to reach in other settings and who rarely visit their general practitioner. A sizeable majority (83%) of NSW police had at least one unhealthy life-style behaviour with 19% reporting 3-5 unhealthy factors. The high prevalence of excessive alcohol consumption among police is of particular concern. More active health promotion and provision of brief interventions among police may reduce morbidity and mortality associated with unhealthy life-styles.     

Time-specific extinction and recovery of the rabbit's (Oryctolagus cuniculus) conditioned nictitating membrane response using mixed interstimulus intervals.

Extinguishing a conditioned response (CR) has entailed separating the conditioned stimulus (CS) from the unconditioned stimulus (US). This research reveals that elimination of the rabbit nictitating membrane response occurred during continuous CS-US pairings. Initial training contained a mixture of 2 CS-US interstimulus intervals (ISIs), 150 ms and 500 ms. The CRs showed double peaks, one for each ISI. When the 150-ms ISI was removed, its CR peak showed 2 hallmarks of extinction: a decline across sessions and spontaneous recovery between sessions. When a further stage of training was introduced with a distinctive CS using the 150-ms ISI, occasional tests of the original, extinguished CS revealed another hallmark of extinction, specifically, strong recovery of the 150-ms peak. These results support both abstract and cerebellar models of conditioning that encode the CS into a cascade of microstimuli, while challenging theories of extinction that rely on changes in CS processing, US representations, and contextual control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)