Growth and nutrient utilization of Murray cod Maccullochella peelii peelii (Mitchell) fingerlings fed diets with varying levels of soybean meal and blood meal

The Australian native freshwater fish Murray cod, Maccullochella peelii pellii (Mitchell), currently supports a fledgling inland aquaculture industry, which is thought to have considerable growth potential. The aim of this study was to evaluate the suitability of two alternate protein sources [blood meal (BM) and defatted soybean meal (SBM)] as substitutes for fish meal at various levels of inclusion in diets for juvenile Murray cod. The growth performance of juvenile Murray cod in response to nine isonitrogenous and isocalorific diets (50% protein, 14% lipid, 20.2 kJ g⁻¹) consisting of a control diet in which protein was supplied from fish meal, and test diets in which the fish meal protein was substituted at levels of 8%, 16%, 24%, and 32% with BM or SBM was evaluated from a 70-day growth experiment. The per cent apparent dry matter (% ADC_dm) and percentage protein digestibility (% ADC_p) of the test diets were also determined using Cr₂O₃ as a marker. Survival in all the SBM dietary treatments was high but that of fish on the BM dietary treatments was significantly (P < 0.05) lower than in all the other dietary treatments. Specific growth rate (% day−1) of Murray cod fed SBM incorporated diets ranged from 1.63 ± 0.06 to 1.78 ± 0.10 and even at the highest level tested (32% of the dietary protein from SBM) was not significantly different (P > 0.05) from the fish fed the control diet (1.65 ± 0.09). Feed conversion ratios of the SBM dietary treatments ranged from 1.36 ± 0.08 to 1.45 ± 0.07. The protein efficiency ratios and protein conversion efficiencies of Murray cod in the soybean meal treatments were also good and for a majority of the SBM diets were better than those for the control diet. Per cent ADC_dm and ADC_p of the SBM diets tested ranged from 70.6 ± 1.46 to 72.3 ± 1.81% and 88.6 ± 0.57 to 90.3 ± 0.17%, respectively, and was not significantly different (P > 0.05) from the control diet (% ADC_dm 74.3 ± 1.63; % ADC_p 91.3 ± 0.55). The reasons for significantly poor survival and growth of Murray cod reared on BM incorporated diets, and relatively poor digestibility of these diets are discussed. The study shows that for Murray cod diets in which fish meal protein is substituted up to 32% performance or carcass composition is not compromised.

Endurance training in humans leads to fiber type-specific increases in levels of peroxisome proliferator-activated receptor-[gamma] coactivator-1 and peroxisome proliferator-activated receptor-[alpha] in skeletal muscle

The peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1 (PGC-1) can induce mitochondria biogenesis and has been implicated in the development of oxidative type I muscle fibers. The PPAR isoforms α, β/δ, and γ control the transcription of genes involved in fatty acid and glucose metabolism. As endurance training increases skeletal muscle mitochondria and type I fiber content and fatty acid oxidative capacity, our aim was to determine whether these increases could be mediated by possible effects on PGC-1 or PPAR-α, -β/δ, and -γ. Seven healthy men performed 6 weeks of endurance training and the expression levels of PGC-1 and PPAR-α, -β/δ, and -γ mRNA as well as the fiber type distribution of the PGC-1 and PPAR-α proteins were measured in biopsies from their vastus lateralis muscle. PGC-1 and PPAR-α mRNA expression increased by 2.7- and 2.2-fold (P < 0.01), respectively, after endurance training. PGC-1 expression was 2.2- and 6-fold greater in the type IIa than in the type I and IIx fibers, respectively. It increased by 2.8-fold in the type IIa fibers and by 1.5-fold in both the type I and IIx fibers after endurance training (P < 0.015). PPAR-α was 1.9-fold greater in type I than in the II fibers and increased by 3.0-fold and 1.5-fold in these respective fibers after endurance training (P < 0.001). The increases in PGC-1 and PPAR-α levels reported in this study may play an important role in the changes in muscle mitochondria content, oxidative phenotype, and sensitivity to insulin known to be induced by endurance training.

Age-related differences in physical activity levels of young adults.

Purpose: To examine age-related differences in the physical activity behaviors of young adults.

Methods: We examined rates of participation in vigorous- and moderate-intensity leisure-time activity and walking, as well as an index of physical activity sufficient for health benefits in three Australian cross-sectional samples, for the age ranges of 18–19, 20–24, and 25–29 yr. Data were collected in 1991, 1996, and 1997/8.

Results: There was at least a 15% difference in vigorous-intensity leisure-time physical activity from the 18–19 yr to the 25–29 yr age groups, and at least a 10% difference in moderate-intensity leisure-time physical activity. For the index of sufficient activity there was a difference between 9 and 21% across age groups. Differences in rates of walking were less than 8%. For all age groups, males had higher rates of participation for vigorous and moderate-intensity activity than did females, but females had much higher rates of participation in walking than males. Age-associated differences in activity levels were more apparent for males.

Conclusions: Promoting walking and various forms of moderate-intensity physical activities to young adult males, and encouraging young adult females to adopt other forms of moderate-intensity activity to complement walking may help to ameliorate decreases in physical activity over the adult lifespan.

Assessment of three levels of folic acid on serum folate and plasma homocysteine: a randomised placebo-controlled double-blind dietary intervention trial.

Objective: To determine the minimum effective dose of folic acid required to appreciably increase serum folate and to produce a significant reduction in plasma total homocysteine (tHcy).

Design: Double-blind, randomised placebo-controlled intervention trial.

Setting: Community-based project in a New Zealand city.

Subjects: Seventy free living men and women with tHcy10 µmol/l. Mean age (range) was 58 (29-90) y.

Interventions: Daily consumption over 4 weeks of 20 g breakfast cereal either unfortified (placebo) or fortified with 100, 200 or 300 µg folic acid. Dietary intake was determined by weighed diet records and consumption of commercially fortified products was avoided.

Main outcome measures: Plasma tHcy and serum folate concentrations.

Results: Average serum folate concentrations (95% CI) increased significantly in the treatment groups relative to the control group by 28(9-51)%, 60(37-87)% and 79(51-114)% for supplementation with 100, 200 and 300 µg folic acid, respectively. A reduction in tHcy was observed, being 16(8-22)%, 12(4-18)% and 17(9-24)% in the three treatment groups, respectively.

Conclusions: A regular intake of as little as 100 µg folic acid per day was sufficient to lower tHcy in persons at the upper end of the normal range for tHcy. Low-level fortification may also be appropriate for lowering the risk of neural tube defects given that, when aggregated from all sources, the total intake of folic acid may be sufficiently high to adequately improve the folate status of young women.

Growth performance, feed efficiency and fatty acid composition of juvenile Murray cod, Maccullochella peelii peelii, fed graded levels of canola and linseed oil

n two independent experiments, the effects of dietary inclusion of canola and linseed oil were evaluated in juvenile Murray cod (Maccullochella peelii peelii, Mitchell) over a 112-day period. In each experiment, fish received one of five semi-purified diets in which the dietary fish oil was replaced with canola oil (Experiment A) or linseed oil (Experiment B) in graded increments of 25% (0–100%). Murray cod receiving the graded canola and linseed oil diets ranged in final weight from 112.7 ± 7.6 to 73.8 ± 9.9 g and 93.9 ± 3.6 to 74.6 ± 2.2 g, respectively, and exhibited a negative trend in growth as the inclusion level increased. The fatty acid composition of the fillet and liver were modified extensively to reflect the fatty acid composition of the respective diets. Levels of oleic acid (18:1 n-9) and linoleic acid (18:2 n-6) increased with each level of canola oil inclusion while levels of α-linolenic acid (18:3 n-3) increased with each level of linseed oil inclusion. The concentration of n-3 highly unsaturated fatty acids in the fillet and liver decreased as the amount of vegetable oil in the diets increased. It is shown that the replacement of fish oil with vegetable oils in low fish meal diets for Murray cod is possible to a limited extent. Moreover, this study reaffirms the suggestion for the need to conduct ingredient substitution studies for longer periods and where possible to base the conclusions on regression analysis in addition to anova.

Dealing constructively with negatively evaluated emotional situations: the key to understanding the different reactions of teachers with high and low levels of emotional intelligence

Recent work on the distinctive features of emotions appraised as either negative or positive has links to the investigation of differences in levels of emotional intelligence. In a study with experienced teachers as participants, it was found that emotional reactions to positive or negative situations was moderated by level of emotional intelligence. The reactions to positively charged emotional situations involving students and peers were similar for teachers with high and low levels of emotional intelligence, although the low level group showed somewhat lower likelihood of making an “emotionally intelligent” response compared to the high level group. A much sharper contrast in response likelihood was found for negatively charged emotional situations involving students and peers. Teachers with high levels of emotional intelligence responded quite differently to those with low levels of emotional intelligence. The results indicate the prospect of clarifying a neglected area of exploration of differences in the likely behaviour of teachers differing in levels of emotional intelligence.

The sustainability of health promotion interventions for different levels of social organization

In health promotion, enthusiasm for sustainability has frequently overshadowed critical reflection with regard to whether this aim is warranted, let alone feasible. Consequently, the not insubstantial body of literature on sustainability in health promotion is not particularly helpful to decision makers. In this paper we seek to provide some guidance for the development of sustainability for health promotion interventions, arguing that it is necessary to be able to differentiate between (i) levels of social organization which are the focus of change, (ii) the programmes and agencies which are the means employed to achieve change, and (iii) the outcomes or effects that are achieved. Furthermore, funding allocations need to be congruent with programme characteristics if one is serious about achieving sustainability.

Levels of physical activity for colon cancer prevention compared with generic public health recommendations: population prevalence and sociodemographic correlates

Background: The proportion of Australian adults achieving physical activity levels believed to be sufficient for colon cancer prevention was estimated, and sociodemographic correlates (age, gender, educational attainment, occupation, marital status, and children in household) of meeting these levels of activity were analyzed.

Methods: Data from the 2000 National Physical Activity Survey were used to estimate the prevalence of participation in physical activity in relation to three criteria: generic public health recommendations, weekly amount of at least moderate-intensity physical activity currently believed to reduce risk of colon cancer, and weekly amount of vigorous-intensity physical activity believed to reduce risk of colon cancer.

Results: Overall, 46% of adults met the generic public health criterion, 26% met the colon cancer criterion based on participation in at least moderate-intensity physical activity, and 10% met the colon cancer criterion based on vigorous-intensity physical activity. Women were less likely than men to meet the colon cancer criteria. Younger and more educated persons were more likely to meet all three criteria. The most pronounced differences between gender, age, and educational attainment groups were found for meeting the amount of vigorous-intensity physical activity believed to reduce risk of colon cancer.

Conclusions: The population prevalence for meeting proposed physical activity criteria for colon cancer prevention is low and much lower than that related to the more generic public health recommendations. If further epidemiologic studies confirm that high volumes and intensities of activity are required, the public health challenges for colon cancer will be significant.

The need to accumlate human capital across levels of export intensity : activating resources that are increasingly difficult to mobilise

With increasing levels of export intensity, firms begin to face new demands. The first set of resources brought to bear on the issues, and those resources that are most quickly mobilised, are the employees. Indeed, higher levels of exporting require activating relatively less mobile resources through the building of organisational structures and mechanisms for managing repositories of knowledge (particularly organisational specialisation and selectively hiring appropriately skilled staff). This paper explores the management of human capital across different levels of export activity in Australian manufacturing firms. Analyses were based on 90 Australian-headquartered manufacturing exporters that responded to a survey. Overall, the results support the notion that firms need to accumulate knowledge as they internationalise. These results are discussed in terms of their consequences for HRM practices.

Discrimination of educational outcomes between differing levels of critical care programmes by selected

Objective: This study was designed to prioritise educational outcomes for three levels of postgraduate speciality critical care nursing programmes.

Background: Postgraduate speciality education has proliferated within Australia over the past 20 years. However, there is little agreement regarding the expected characteristics, or relevant priorities, of these characteristics of graduates successfully completing these programmes of study.

Method: This study used a mixed-method approach comprising two phases. Initially a survey was mailed to volunteers between March and June 2005 to obtain priorities in educational outcomes for graduates of critical care programmes. This was followed by a stakeholder focus group in May 2006 to refine expected outcomes.

Results: Survey respondents rated educational outcomes that described professional and legal aspects of practice to ensure safe patient care as highest priority for programme graduates. Although most educational outcome statements were considered important for graduates from all levels of courses, increasing levels of practice was described for increasingly higher levels of programmes from Graduate Certificate to Masters Degree.

Conclusion: This study provides an emerging description of the priorities of critical care nursing programmes, with priority given to professional and legal aspects of practice. Further delineation of priorities is necessary to inform ongoing educational development.

Understanding dog owners' increased levels of physical activity : results from RESIDE

We examined the influence of dog ownership on physical activity, independent of demographic, intrapersonal, and perceived environmental factors, in a cross-sectional survey of 1813 adults. Although only 23% of the dog owners walked their dogs 5 or more times per week, the adjusted odds of achieving sufficient physical activity and walking were 57% to 77% higher among dog owners compared with those not owning dogs (P<.05). Dog ownership was independently associated with physical activity and walking. Actively encouraging more dog walking may increase community physical activity levels.

Physiological, morphological and behavioural effects of selecting zebra finches for divergent levels of corticosterone

The effects of environmental stress on the physiology and behaviour of higher vertebrates has become an important avenue of research in recent years. Evidence from recent studies has suggested that the avian stress-related hormone corticosterone (CORT) may play a role in immunocompetence and sexual selection. We tested whether CORT is immunosuppressive by studying humoral and cell-mediated immune responses in populations of captive zebra finches selected for divergent peak levels of CORT. We also investigated whether selection for peak CORT has an effect on the quality of several sexually selected regions of the male zebra finch; in addition we compared morphometric parameters and the dominance ranking in males from the different selection lines. We also tested whether different components of the immune system compete for limited resources. We found that selection for divergent levels of peak CORT had little effect on humoral immunity, male sexual signal quality or dominance ranking. However, contrary to expectations, we did find a positive relationship between CORT titre and cell-mediated immunity, as well as a greater cell-mediated response in the birds selected for high CORT titre than those selected for low CORT titre. Consistent with predictions, significant negative relationships were found between both testosterone and CORT titre on humoral immunity. Birds from the low CORT lines were significantly larger in terms of skeletal size than those from the high CORT lines. Overall, our results suggest that the cell-mediated immune response is associated with a reduction in the humoral response, but only in males, and that there is no simple relationship between peak CORT levels and immune function.

Minimising colonic fermentation of high fructan foods : using food processing techniques to reduce levels of fructans in onion and garlic

Background: Irritable Bowel Syndrome (IBS) is a chronic functional disorder of the bowel, affecting up to 15% of Australian adults. Dietary triggers need to be identified and controlled. Researchers have shown that short chain carbohydrates, fructans (high in onion and garlic) play a major role in triggering IBS symptoms. Current dietary management aims to limit the intake of fructans in the diet. Another approach may be to use simple food processing to reduce fructans in foods.

Objective: To investigate if pickling will reduce fructan levels in garlic and shallots, and if pickled garlic and shallots reduce colonic fermentation, and  abdominal symptoms in human volunteers.

Design: Fructan levels of the garlic and shallots were measured using the Megazyme fructan assay. 18 volunteers (13 healthy and 5 IBS) participated in a single blinded, randomised cross over study. Subjects were randomly assigned to receive a breakfast (potato and salmon patty) that was either high (unprocessed) or low (processed/pickled) in garlic and shallots. Breath hydrogen was measured every hour over a ten hour period, and abdominal symptoms were assessed using validated questionnaires.

Outcomes: Pickling over a 12 day period significantly reduced fructan levels in both garlic (p=.0.00) and shallots (p=0.00). Consumption of the low fructan breakfast resulted in significantly lower breath hydrogen (p=0.05), abdominal pain (p=0.032), and wind (p=0.04).

Conclusion: Pickling results in significantly lowered fructan levels in problem foods- shallots and garlic, and lowered colonic fermentation and abdominal symptoms in both healthy and IBS volunteers. This study provides another dietary strategy for dietetic counselling of patients with IBS.