Vertical flow in the Southern Ocean estimated from individual moorings

In this study, we demonstrate that oceanic vertical velocities can be estimated from individual mooring measurements, even for non-stationary flow. This result is obtained under three assumptions: i. weak diffusion (Péclet number ≫1), ii. weak friction (Reynolds number ≫1), and iii. small inertial terms (Rossby number ≪1). The theoretical framework is applied to a set of 4 moorings located in the Southern Ocean. For this site, the diagnosed vertical velocities are highly variable in time, their standard deviation being one-to-two orders of magnitude greater than their mean. We demonstrate that the time-averaged vertical velocities are largely induced by geostrophic flow, and can be estimated from the time-averaged density and horizontal velocities. This suggests that local time-mean vertical velocities are primarily forced by the time-mean ocean dynamics, rather than by e.g. transient eddies or internal waves. We also show that, in the context of these four moorings, the time-mean vertical flow is consistent with stratified Taylor column dynamics in the presence of a topographic obstacle

My heart is racing! Psychophysiological dynamics of skilled racecar drivers

Our purpose was to test the multi-action plan (MAP) model assumptions in which athletes’ psychophysiological patterns differ among optimal and suboptimal performance experiences. Nine professional drivers competing in premier race categories (e.g., Formula 3, Porsche GT3 Cup Challenge) completed the study. Data collection involved monitoring the drivers’ perceived hedonic tone, accuracy on core components of action, posture, skin temperature, respiration rate, and heart rate responses during a 40-lap simulated race. Time marks, gathered at three standardized sectors, served as the performance variable. The A1GP racing simulator (Allinsport, Modena) established a realistic race platform. Specifically, the Barcelona track was chosen due to its inherently difficult nature characterized by intermittent deceleration points. Idiosyncratic analyses showed large individual differences in the drivers’ psychophysiological profile, as well as distinct patterns in regards to optimal and suboptimal performance experiences. Limitations and future research avenues are discussed. Action (e.g., attentional control) and emotion (e.g., biofeedback training) centered applied sport psychology implications are advanced

Modification of turbulent dissipation rates by a deep Southern Ocean eddy

The impact of a mesoscale eddy on the magnitude and spatial distribution of diapycnal ocean mixing is investigated using a set of hydrographic and microstructure measurements collected in the Southern Ocean. These data sampled a baroclinic, mid-depth eddy formed during the disintegration of a deep boundary current. Turbulent dissipation is suppressed within the eddy, but is elevated by up to an order of magnitude along the upper and lower eddy boundaries. A ray-tracing approximation is employed asa heuristic device to elucidate how the internal wave field evolves in the ambient velocity and stratification conditions accompanying the eddy. These calculations are consistent with the observations, suggesting reflection of internal wave energy from the eddy center and enhanced breaking through critical layer processes along the eddy boundaries. These results have important implications for understanding where and how internal wave energy is dissipated in the presence of energetic deep geostrophic flows

Exogenous phytase and xylanase exhibit opposing effects on real-time gizzard pH in broiler chickens

1. The current study was conducted to evaluate the influence of high phytase doses and xylanase, individually and in combination, on performance, blood inositol and real time gastric pH in broilers fed wheat-based diets.  2. In a 42 d experiment, a total of 576 male Ross 308 broiler chicks were allocated to four dietary treatments. Treatments consisted of a 2 × 2 factorial arrangement, with 500 or 2500 FTU/kg phytase and 0 or 16000 BXU/kg xylanase, fed in two phases (starter 0–21; grower 21–42 d). Heidelberg pH capsules were administered to eight birds from each treatment group, pre and post diet phase change, with readings captured over a 5.5 h period.  3. At 21 and 42 d, birds fed 500 FTU/kg phytase without xylanase had on average 127g and 223 g lower weight gain than all other treatments, respectively (P<0.05). At 21 d, FCR was reduced (P<0.01) by 2500 FTU/kg phytase or xylanase, however, 42 d FCR was unaffected by enzyme treatment. Inositol content of plasma was twice that of the erythrocyte (P<0.001), with 2500 FTU/kg phytase tending to increase (P=0.07) inositol content in both blood fractions.  4. Across all treatments, capsule readings ranged from pH 0.54 to 4.84 in the gizzard of broilers. Addition of 2500 FTU/kg phytase to the grower diet reduced (P<0.05) average gizzard pH from 2.89 to 1.69, whilst feeding xylanase increased (P<0.001)gizzard pH from 2.04 to 2.40. In contrast, digital probe measurements showed no effect of xylanase on gizzard pH, while addition of 2500 FTU/kg phytase increased (P=0.05) pH compared to 500 FTU/kg phytase with or without xylanase.  5. These findings suggested that xylanase and high phytase doses have opposite effects on real-time gastric pH, while similarly improving performance of broilers

Exogenous phytase and xylanase exhibit opposing effects on real-time gizzard pH in broiler chickens

1. The current study was conducted to evaluate the influence of high phytase doses and xylanase, individually and in combination, on performance, blood inositol and real time gastric pH in broilers fed wheat-based diets.  2. In a 42 d experiment, a total of 576 male Ross 308 broiler chicks were allocated to four dietary treatments. Treatments consisted of a 2 × 2 factorial arrangement, with 500 or 2500 FTU/kg phytase and 0 or 16000 BXU/kg xylanase, fed in two phases (starter 0–21; grower 21–42 d). Heidelberg pH capsules were administered to eight birds from each treatment group, pre and post diet phase change, with readings captured over a 5.5 h period.  3. At 21 and 42 d, birds fed 500 FTU/kg phytase without xylanase had on average 127g and 223 g lower weight gain than all other treatments, respectively (P<0.05). At 21 d, FCR was reduced (P<0.01) by 2500 FTU/kg phytase or xylanase, however, 42 d FCR was unaffected by enzyme treatment. Inositol content of plasma was twice that of the erythrocyte (P<0.001), with 2500 FTU/kg phytase tending to increase (P=0.07) inositol content in both blood fractions.  4. Across all treatments, capsule readings ranged from pH 0.54 to 4.84 in the gizzard of broilers. Addition of 2500 FTU/kg phytase to the grower diet reduced (P<0.05) average gizzard pH from 2.89 to 1.69, whilst feeding xylanase increased (P<0.001)gizzard pH from 2.04 to 2.40. In contrast, digital probe measurements showed no effect of xylanase on gizzard pH, while addition of 2500 FTU/kg phytase increased (P=0.05) pH compared to 500 FTU/kg phytase with or without xylanase.  5. These findings suggested that xylanase and high phytase doses have opposite effects on real-time gastric pH, while similarly improving performance of broilers

The effectiveness and cost-effectiveness of acupressure for the control and management of chemotherapy-related acute and delayed nausea: Assessment of Nausea in Chemotherapy Research (ANCHoR), a randomised controlled trial

Chemotherapy-induced nausea and vomiting remain difficult symptoms to manage in clinical practice. As standard antiemetic drugs do not fully eliminate these symptoms, it is important to explore the adjuvant role of non-pharmacological and complementary therapies in antiemetic management approaches. Acupressure is one such treatment showing highly suggestive evidence so far of a positive effect, meriting further investigation