Skeletal muscle proteins involved in fatty acid transport influence fatty acid oxidation rates observed during exercise.

Several proteins are implicated in transmembrane fatty acid transport. The purpose of this study was to quantify the variation in fatty acid oxidation rates during exercise explained by skeletal muscle proteins involved in fatty acid transport. Seventeen endurance-trained males underwent a (i) fasted, incremental cycling test to estimate peak whole-body fatty acid oxidation rate (PFO), (ii) resting vastus lateralis microbiopsy, and (iii) 2 h of fed-state, moderate-intensity cycling to estimate whole-body fatty acid oxidation during fed-state exercise (FO). Bivariate correlations and stepwise linear regression models of PFO and FO during 0-30 min (early FO) and 90-120 min (late FO) of continuous cycling were constructed using muscle data. To assess the causal role of transmembrane fatty acid transport in fatty acid oxidation rates during exercise, we measured fatty acid oxidation during in vivo exercise and ex vivo contractions in wild-type and CD36 knock-out mice. We observed a novel, positive association between vastus lateralis FATP1 and PFO and replicated work reporting a positive association between FABPpm and PFO. The stepwise linear regression model of PFO retained CD36, FATP1, FATP4, and FABPpm, explaining ~87% of the variation. Models of early and late FO explained ~61 and ~65% of the variation, respectively. FATP1 and FATP4 emerged as contributors to models of PFO and FO. Mice lacking CD36 had impaired whole-body and muscle fatty acid oxidation during exercise and muscle contractions, respectively. These data suggest that substantial variation in fatty acid oxidation rates during exercise can be explained by skeletal muscle proteins involved in fatty acid transport.

Carbohydrate intake before and during high intensity exercise with reduced muscle glycogen availability affects the speed of muscle reoxygenation and performance.

Muscle glycogen state and carbohydrate (CHO) supplementation before and during exercise may impact responses to high-intensity interval training (HIIT). This study determined cardiorespiratory, substrate metabolism, muscle oxygenation, and performance when completing HIIT with or without CHO supplementation in a muscle glycogen depleted state. On two occasions, in a cross-over design, eight male cyclists performed a glycogen depletion protocol prior to HIIT during which either a 6% CHO drink (60 g.hr-1) or placebo (%CHO, PLA) was consumed. HIIT consisted of 5 × 2 min at 80% peak power output (PPO), 3 × 10-min bouts of steady-state (SS) cycling (50, 55, 60% PPO), and a time-to-exhaustion (TTE) test. There was no difference in SS [Formula: see text], HR, substrate oxidation and gross efficiency (GE %) between CHO and PLA conditions. A faster rate of muscle reoxygenation (%. s-1) existed in PLA after the 1st (Δ - 0.23 ± 0.22, d = 0.58, P < 0.05) and 3rd HIIT intervals (Δ - 0.34 ± 0.25, d = 1.02, P < 0.05). TTE was greater in CHO (7.1 ± 5.4 min) than PLA (2.5 ± 2.3 min, d = 0.98, P < 0.05). CHO consumption before and during exercise under reduced muscle glycogen conditions did not suppress fat oxidation, suggesting a strong regulatory role of muscle glycogen on substrate metabolism. However, CHO ingestion provided a performance benefit under intense exercise conditions commenced with reduced muscle glycogen. More research is needed to understand the significance of altered muscle oxygenation patterns during exercise.

Converting avocado seeds into a ready to eat snack and analysing for persin and amygdalin.

Avocado seeds account for 13% of the waste from industrial production of cold-pressed avocado oil (CPAO). Therefore, the aim of this study was to valorise avocado seeds by converting it into an extruded snack product using a friction cooker and comparing their textural and physical characteristics to extruded brown rice and malted barley ready to eat (RTE) snacks. Concentration of toxins; amygdalin and persin were compared in extruded avocado seed and fresh avocado seeds. Avocado seed extrudates were significantly lower in lateral expansion, apparent density, porosity, hardness, and crispiness compared to brown rice extrudates. Antioxidant capacity and total phenolic content (TPC) was highest in freeze-dried avocado seeds. Antioxidant capacity and TPC of avocado seed extrudates were significantly higher than brown rice and malted barley. The concentrations of both amygdalin and persin in the RTE avocado seed snack were present at non-toxic levels (2.6 × 10-6 mg/g and 0.68 mg/g respectively).

Peak fat oxidation is positively associated with vastus lateralis CD36 content, fed-state exercise fat oxidation, and endurance performance in trained males.

PURPOSE: Whole-body fat oxidation during exercise can be measured non-invasively during athlete profiling. Gaps in understanding exist in the relationships between fat oxidation during incremental fasted exercise and skeletal muscle parameters, endurance performance, and fat oxidation during prolonged fed-state exercise. METHODS: Seventeen endurance-trained males underwent a (i) fasted, incremental cycling test to assess peak whole-body fat oxidation (PFO), (ii) resting vastus lateralis microbiopsy, and (iii) 30-min maximal-effort cycling time-trial preceded by 2-h of fed-state moderate-intensity cycling to assess endurance performance and fed-state metabolism on separate occasions within one week. RESULTS: PFO (0.58 ± 0.28 g.min-1) was associated with vastus lateralis citrate synthase activity (69.2 ± 26.0 µmol.min-1.g-1 muscle protein, r = 0.84, 95% CI 0.58, 0.95, P < 0.001), CD36 abundance (16.8 ± 12.6 µg.g-1 muscle protein, rs = 0.68, 95% CI 0.31, 1.10, P = 0.01), pre-loaded 30-min time-trial performance (251 ± 51 W, r = 0.76, 95% CI 0.40, 0.91, P = 0.001; 3.2 ± 0.6 W.kg-1, r = 0.62, 95% CI 0.16, 0.86, P = 0.01), and fat oxidation during prolonged fed-state cycling (r = 0.83, 95% CI 0.57, 0.94, P < 0.001). Addition of PFO to a traditional model of endurance (peak oxygen uptake, power at 4 mmol.L-1 blood lactate concentration, and gross efficiency) explained an additional ~ 2.6% of variation in 30-min time-trial performance (adjusted R2 = 0.903 vs. 0.877). CONCLUSION: These associations suggest non-invasive measures of whole-body fat oxidation during exercise may be useful in the physiological profiling of endurance athletes.

Temperate performance and metabolic adaptations following endurance training performed under environmental heat stress.

Endurance athletes are frequently exposed to environmental heat stress during training. We investigated whether exposure to 33°C during training would improve endurance performance in temperate conditions and stimulate mitochondrial adaptations. Seventeen endurance-trained males were randomly assigned to perform a 3-week training intervention in 18°C (TEMP) or 33°C (HEAT). An incremental test and 30-min time-trial preceded by 2-h low-intensity cycling were performed in 18°C pre- and post-intervention, along with a resting vastus lateralis microbiopsy. Training was matched for relative cardiovascular demand using heart rates measured at the first and second ventilatory thresholds, along with a weekly "best-effort" interval session. Perceived training load was similar between-groups, despite lower power outputs during training in HEAT versus TEMP (p < .05). Time-trial performance improved to a greater extent in HEAT than TEMP (30 ± 13 vs. 16 ± 5 W, N = 7 vs. N = 6, p = .04), and citrate synthase activity increased in HEAT (fold-change, 1.25 ± 0.25, p = .03, N = 9) but not TEMP (1.10 ± 0.22, p = .22, N = 7). Training-induced changes in time-trial performance and citrate synthase activity were related (r = .51, p = .04). A group × time interaction for peak fat oxidation was observed (Δ 0.05 ± 0.14 vs. -0.09 ± 0.12 g·min-1 in TEMP and HEAT, N = 9 vs. N = 8, p = .05). Our data suggest exposure to moderate environmental heat stress during endurance training may be useful for inducing adaptations relevant to performance in temperate conditions.

Optimising the Spray Drying of Avocado Wastewater and Use of the Powder as a Food Preservative for Preventing Lipid Peroxidation.

Avocado wastewater (AWW) is the largest by-product of cold pressed avocado oil. The aim of this study was to valorise AWW by converting it into spray dried powder for use as a lipid peroxidation inhibiting food preservative. To increase the powder yield of AWW, addition of carriers and spray drying parameters (temperature and feed flow rate) were optimised. The highest AWW powder yield was 49%, and was obtained using 5% whey protein concentrate (WPC), with a feed flow rate of 5.8 g/min and an inlet drying temperature of 160 °C. The liquid chromatography mass spectrophotometry (LC-MS) analysis showed that AWW encapsulated with WPC had the highest retention of α-tocopherol (181.6 mg/kg powder). AWW with 5% WPC was tested as a preservative in pork fat cooked at 180 °C for 15 min. Thiobarbaturic acid reactive substances (TBARS) assay showed that the effectiveness of AWW powder was comparable to commercial additives such as butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and sodium erythorbate (E316).

Organisational culture: the hidden operand in clinical laboratories.

PURPOSE: The purpose of this paper is to present organisational cultural determinants that can influence total quality management (TQM) in clinical laboratories. DESIGN/METHODOLOGY/APPROACH: This is a viewpoint paper using evidence provided by a literature research about cultural patterns using Competing Values Framework to explain the relationship between organisational culture and TQM. FINDINGS: Cultural aspects likely to enhance creativity and innovation are considered as incentives in promoting cultural transformation. TQM in the average modern clinical laboratory requires a long overdue transformational change in values, culture and attitude. SOCIAL IMPLICATIONS: Valuing people, making up an organisation, is expected to enhance TQM. ORIGINALITY/VALUE: This paper provokes a shift in thinking among traditional clinical laboratory managers and results in a win-win for both staff and total quality outcomes.

First complete genome sequence of vanilla mosaic strain of Dasheen mosaic virus isolated from the Cook Islands.

We present the first complete genome of vanilla mosaic virus (VanMV). The VanMV genomic structure is consistent with that of a potyvirus, containing a single open reading frame (ORF) encoding a polyprotein of 3139 amino acids. Motif analyses indicate the polyprotein can be cleaved into the expected ten individual proteins; other recognised potyvirus motifs are also present. As expected, the VanMV genome shows high sequence similarity to the published Dasheen mosaic virus (DsMV) genome sequences; comparisons with DsMV continue to support VanMV as a vanilla infecting strain of DsMV. Phylogenetic analyses indicate that VanMV and DsMV share a common ancestor, with VanMV having the closest relationship with DsMV strains from the South Pacific.

Diversity and evolutionary history of lettuce necrotic yellows virus in Australia and New Zealand.

Lettuce necrotic yellows virus (LNYV) is the type member of the genus Cytorhabdovirus, family Rhabdoviridae, and causes a severe disease of lettuce (Lactuca sativa L.). This virus has been described as endemic to Australia and New Zealand, with sporadic reports of a similar virus in Europe. Genetic variability studies of plant-infecting rhabdoviruses are scarce. We have extended a previous study on the variability of the LNYV nucleocapsid gene, comparing sequences from isolates sampled from both Australia and New Zealand, as well as analysing symptom expression on Nicotiana glutinosa. Phylogenetic and BEAST analyses confirm separation of LNYV isolates into two subgroups (I and II) and suggest that subgroup I is slightly older than subgroup II. No correlation was observed between isolate subgroup and disease symptoms on N. glutinosa. The origin of LNYV remains unclear; LNYV may have moved between native and weed hosts within Australia or New Zealand before infecting lettuce or may have appeared as a result of at least two incursions, with the first coinciding with the beginning of European agriculture in the region. The apparent extinction of subgroup I in Australia may have been due to less-efficient dispersal than that which has occurred for subgroup II - possibly a consequence of suboptimal interactions with plant and/or insect hosts. Introduction of subgroup II to New Zealand appears to be more recent. More-detailed epidemiological studies using molecular tools are needed to fully understand how LNYV interacts with its hosts and to determine where the virus originated.