Improved beef production from supplementation of Hereford, Brahman and crossbred cattle grazing low and medium quality pastures in the subtropics of Australia

Subtropical grasslands are low in organic matter digestibility (OMD) (0.60) and nitrogen (N) (15 g/kg) for much of the year and this limits cattle production which is characterized by low calving rates and low weaning weights. Production has been based on Bos taurus British breeds of cattle but this is changing and now many breeding herds comprise B, indicus cows and their crosses. This change has increased some aspects of production, but low calving rates persist. A 4-year study was undertaken with a view to improve calving rates and weaner output by supplementing cows grazing either native or improved pastures with a high protein oilseed meal (cottonseed meal; CSM) on four sites. These sites were subdivided into a total of 36 paddocks to allow for two replications in a 3 breeds X 3 supplementation rates X 2 pastures factorial design. Selected cows (no. = 216) from Hereford (H), Brahman (B) and Brahman X Hereford (BH) breed types were set to graze either native pastures (0.45 to 0.62 OMD, 8 to 15 g N per kg; low quality) or improved pastures (0.47 to 0.67 OA ID, 10 to 22 g N per kg; medium quality). Cows were given either 0, 750 or 1500 g/day of CSM for 130 days from calving until 4 weeks into a 12- to 13-week mating period. The CSM was given as two meals per week. Live weight at mating of cows on the low quality pasture was increased (P < 0.01) over those not supplemented by feeding either 750 g CSM per day (H and B cows) or 1500 g CSM per day tall cows). There was no significant effect of supplementation on the mating weights of B cows grazing the medium quality sites. Calving rate of B cows was not increased by their supplementation on either low (4-year mean 58.3 %) or medium quality pastures (66.8%) but did tend to be higher in H cows when supplemented at 1500 g CSM per day on the low (66.7 v. 78.0 (s.e. 6.09) %; P < 0.1) and medium quality pastures (70.5 v. 93.5 (s.e. 4.72) %). An increased calving rate (65.8 (s.e. 6.6) % to 83.2 (s.e. 5.82) % in supplemented BH cows grazing low quality pastures approached significance (P < 0.1) when given CSM at 1500 g/day but there was no increased trend in calving rate when this breed type was supplemented on medium quality pastures. Weaning weights of calves from and B and BH cows were increased (P < 0.05) by supplementation of their darns at 750 g/day and for calves weaned from H cows supplemented at 1500 g/day of CSM. Supplementation at 1500 g/day on low quality pastures increased weaner output per cow mated by 120% for H, by 65% for BH cows and by 50% for B cows. Weaner output was increased by 34 and 40%, respectively, for B and H cows when supplemented at 750 g/day and grazing medium quality pastures but there teas no significant effect of supplementation on output from BH cows. Responses in many parameters differed between years. These results were interpreted as a response to the protein in the oilseed meal supplement by B, taurus and B. taurus X B. indicus cross cows grazing on the subtropical pastures. The study also highlighted that responses to the meal differed between breed types, between the quality of the grazed pasture and between the years of supplementation.

Selection of a strain of Aspergillus for the production of citric acid from pineapple waste in solid-state fermentation

Aspergillus foetidus ACR I 3996 (=FRR 3558) and three strains of Aspergillus niger ACM 4992 (=ATCC 9142), ACM 4993 (=ATCC 10577), ACM 4994 (=ATCC 12846) were compared for the production of citric acid from pineapple peel in solid-state fermentation. A. niger ACM 4992 produced the highest amount of citric acid, with a yield of 19.4 g of citric acid per 100 g of dry fermented pineapple waste under optimum conditions, representing a yield of 0.74 g citric acid/g sugar consumed. Optimal conditions were 65% (w/w) initial moisture content, 3% (v/w) methanol, 30 degrees C, an unadjusted initial pH of 3.4, a particle size of 2 mm and 5 ppm Fe2+. Citric acid production was best in flasks, with lower yields being obtained in tray and rotating drum bioreactors.

Erosion/productivity modelling of maize farming in the Philippine uplands part III: Economic analysis of alternative farming methods

Two previous papers in this series (Nelson et al., this issue) described the use of the Agricultural Production Systems Simulator (APSIM) to simulate the effect of erosion on maize yields from open-field farming and hedgerow intercropping in the Philippine uplands. In this paper, maize yields simulated with APSIM are used to compare the economic viability of intercropping maize between leguminous shrub hedgerows with that of continuous and fallow open-field farming of maize. The analysis focuses on the economic incentives of upland farmers to adopt hedgerow intercropping, discussing farmers' planning horizons, access to credit and security of land tenure, as well as maize pricing in the Philippines. Insecure land tenure has limited the planning horizons of upland farmers, and high establishment costs reduce the economic viability of hedgerow intercropping relative to continuous and fallow open-field farming in the short term, In the long term, high discount rates and share-tenancy arrangements in which landlords do not contribute to establishment costs reduce the economic viability of hedgerow intercropping relative to fallow open-field farming, (C) 1998 Elsevier Science Ltd. All rights reserved.

Success of surgery for primary aldosteronism judged by residual autonomous aldosterone production

Since February 1996 we have prospectively assessed residual adrenal autonomy by the fludrocortisone suppression test (FST) in 23 patients 3 months after unilateral adrenalectomy for Conn syndrome and in 45 patients after a longer interval. In regard to blood pressure, 36 (53%) patients were cured of hypertension and the remaining 32 (47%) patients had improved hypertension control at the time of their latest postoperative clinical assessment. In regard to the outcome of surgery, patients who achieved normal suppressibility of aldosterone were regarded as cured, and those who had greater suppressibility after surgery were considered improved. Time since surgery for the whole group averaged 26 months. By these biochemical criteria, 42 patients (62%) were cured by surgery, and the rest improved; 16 (76%) of 21 women were cured, and 26 (55%) of 47 men. The women (mean +/- SD age 47 +/- 11 years) were significantly (p < 0.05) younger than the men (52 +/- 9 Sears). Preoperative aldosterone levels before and after FST were similar in the cured and improved groups and fell significantly (p < 0.01) in both groups following surgery. After surgical reduction of autonomous aldosterone production, mean plasma renin activity levels increased sixfold in the cured group and threefold in the improved group. Surgical mortality in this group of 68 patients with Conn syndrome was zero.

A state-contingent production approach to principal-agent problems with an application to point-source pollution control

Two basic representations of principal-agent relationships, the 'state-space' and 'parameterized distribution' formulations, have emerged. Although the state-space formulation appears more natural, analytical studies using this formulation have had limited success. This paper develops a state-space formulation of the moral-hazard problem using a general representation of production under uncertainty. A closed-form solution for the agency-cost problem is derived. Comparative-static results are deduced. Next we solve the principal's problem of selecting the optimal output given the agency-cost function. The analysis is applied to the problem of point-source pollution control. (C) 1998 Published by Elsevier Science S.A. All rights reserved.

Patient matching in treatment for alcohol dependence: is the null hypothesis still alive and well?

In the light of Project MATCH, is it reasonable to accept the null hypothesis that there are no clinically signi® cant matching effects between patient characteristics and cognitive± behaviour therapy (CBT), motivational enhancement therapy (MET) and Twelve-Step facilitation therapy (TSF)? The Project MATCH investigators considered the null hypothesis but preferred the alternative hypothesis that further analysis may reveal combinations of patient and therapist characteristics that show more substantial matching effects than any of the variables that they have examined to date.1

Growth and lactic acid production in batch culture of Lactobacillus rhamnosus in a defined medium

To facilitate metabolic analysis, batch fermentations of Lactobacillus rhamnosus were carried out in a new defined medium. Biomass at 10.5 g/l and lactic acid at 67 g/l with a Y-P/S of 0.84 were achieved. The maximum specific growth rate and the average productivity were 0.49/h and 2.48 g/l.h, respectively. These are comparable to those of this organism and related organisms in complex media. Preliminary amino acid studies were also conducted, highlighting the importance of serine, asparagine, glutamine and cysteine. Kinetic analysis revealed that lactic acid production was predominantly growth-associated with growth associated and non-growth associated lactic acid constants of 0.389 mol/g-cell and 0.0025 mol/g-cell.h, respectively. Finally a kinetic model has been included to describe the fermentation of L. rhamnosus.

Metabolic analysis of poly(3-hydroxybutyrate) production by recombinant Escherichia coli

Poly(3-hydroxybutyrate) (PHB) production by fermentation was examined under both restricted- and ample-oxygen supply conditions in a single fed-batch fermentation. Recombinant Escherichia coli transformed with the PHB production plasmid pSYL107 was grown to reach high cell density (227 g/l dry cell weight) with a high PHB content (78% of dry cell weight), using a glucose-based minimal medium. A simple flux model containing 12 fluxes was developed and applied to the fermentation data. A superior closure (95%) of the carbon mass balance was achieved. When the data were put into use, the results demonstrated a surprisingly large excretion of formate and lactate. Even though periods of severe oxygen limitation coincided with rapid acetate and lactate excretion, PHB productivity and carbon utilization efficiency were not significantly impaired. These results are very positive in reducing oxygen demand in an industrial PHA fermentation without sacrificing its PHA productivity, thereby reducing overall production costs.

Endorsement of CIDI psychosis screening items in the Australian Survey of Mental Health and Well being

This paper presents preliminary analysis of the endorsement of the CIDI Psychosis Screening items in a large Australian community sample. CIDI interviews were completed on a representative sample of 10,641 individuals living in private dwellings in Australia. The items examined constructs related to thought control/interference (G1), ideas of reference (G2), and special powers (G3). If endorsed, each item had a follow-up probe (G1A telepathy; G2A things arranged with special meaning; G3A -- group acceptability). The final item (G4) asked if the respondent had been told that they had schizophrenia. This paper presents the frequency of endorsement, and examines the impact of age and sex on these items. Endorsement of the items was G1 =5.86°/,,, G1A=0.70%, G2=4.84%, G2A=l.31%, G3=3.41%, G3A=2.65%, and G4=0.65%. If screen-positives are defined as two or more 'hits', then 0.41% of the sample met this criterion. Younger participants were significantly more likely to be screen-positive. Items G1, G1A, G2 and G2A were endorsed more frequently by younger participants while there were no significant age effects identified in items G3 or G4. There was a nonsignificant trend for females to endorse item G1 more frequently than males (p = 0.07), but there were no signficant gender differences on the other items. Many individuals who were 'screen-negative' for psychosis endorsed CIDI items related to thought controls, ideas of reference and special powers, suggesting that there may be a 'continuum' of experiences in the population. The impact of age on the distribution of these measures suggests either differential biological vulnerability to these experiences and/or differential cultural factors influencing endorsement of the items. The implications of these findings on our understanding of the symptoms of psychosis will be discussed. The survey was funded by the Commonwealth Dept. of Health and Family Services. The Stanley Foundation supported this project.

Response to price and production risk: The case of Australian wheat

A model of Australian wheat grower supply response was specified under the constraints of price and yield uncertainty, risk aversion, partial adjustment, and quadratic costs. The model was solved to obtain area planted. The results of estimation indicate that risk arising from prices and climate have had a significant influence on producer decision making. The coefficient of relative risk aversion and short-run and long-run elasticities of supply with respect to price were calculated. Wheat growers' risk premium, expected at the start of the season for exposed price and yield risk, was 2.8 percent of revenue or 10.4 percent of profit as measured by producer surplus. (C) 2000 John Wiley & Sons, Inc.

Perceived need for mental health care, findings from the Australian National Survey of Mental Health and Well-being

Background. The Australian National Survey of Mental Health and Well-being was designed to detect and describe psychiatric morbidity, associated disability, service use and perceived need for care. The survey employed a single-phase interview methodology, delivering a field questionnaire to a clustered probability sample of 10641 Australians. Perceived need was sampled with an instrument designed for this survey, the Perceived Need for Care Questionnaire (PNCQ). This questionnaire gathers information about five categories of perceived need, assigning each to one of four levels of perceived need. Reliability and validity studies showed satisfactory performance of the instrument. Methods. Perceived need for mental health care in the Australian population has been analysed using PNCQ data, relating this to diagnostic and service utilization data from the above survey. Results. The survey findings indicate that an estimated 13.8 % of the Australian population have perceived need for mental health care. Those who met interview criteria for a psychiatric diagnosis and also expressed perceived need make up 9.9 % of the population. An estimated 11.0% of the population are cases of untreated prevalence, a minority (3.6% of the population) of whom expressed perceived need for mental health care. Among persons using services, those without a psychiatric diagnosis based on interview criteria (4.4% of the population), showed high levels of perceived met need. Conclusions. The overall rate of perceived need found by this methodology lies between those found in the USA and Canada. The findings suggest that service use in the absence of diagnosis elicited by survey questionnaires may often represent successful intervention. In the survey, untreated prevalence was commonly not accompanied by perceived need for mental health care.

Structured modeling of recombinant protein production in batch and fed-batch culture of baculovirus-infected insect cells

The infection of insect cells with baculovirus was described in a mathematical model as a part of the structured dynamic model describing whole animal cell metabolism. The model presented here is capable of simulating cell population dynamics, the concentrations of extracellular and intracellular viral components, and the heterologous product titers. The model describes the whole processes of viral infection and the effect of the infection on the host cell metabolism. Dynamic simulation of the model in batch and fed-batch mode gave good agreement between model predictions and experimental data. Optimum conditions for insect cell culture and viral infection in batch and fed-batch culture were studied using the model.