SKI SKATING TECHNIQUE CHOICE: MECHANICAL AND PHYSIOLOGICAL FACTORS AFFECTING PERFORMANCE

Ski skating technique choice can potentially influence economy of motion which in turn affects racing performance. Comparisons of skating techniques have demonstrated that uphill slope can influence the relative advantage of one technique versus another. On slopes greater than about 4 to 5 degrees, V1 technique may have physiological advantages over V2 technique. Mechanically this can be explained by positioning differences of skis and poles such that relatively little propulsive force can be generated from the skis using V2. Thus V2 technique demands greater upper body propulsion compared to V1 which produces more propulsive force from each leg's skating stroke. The relatively smaller muscle mass of the upper extremity compared to the legs may explain the greater physiological demands when using V2 skating on uphill terrain

Growth Performance, Nutrient Digestibility, and Retention in Atlantic Salmon, Salmo salar L., Fed Diets with Fermented Sugar Kelp, Saccharina latissima

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Analysis of a sprint ski race and associated laboratory determinants of world-class performance

This investigation was designed to analyze the time-trial (STT) in an international cross-country skiing sprint skating competition for (1) overall STT performance and relative contributions of time spent in different sections of terrain, (2) work rate and kinematics on uphill terrain, and (3) relationships to physiological and kinematic parameters while treadmill roller ski skating. Total time and times in nine different sections of terrain by 12 world-class male sprint skiers were determined, along with work rate and kinematics for one specific uphill section. In addition, peak oxygen uptake (VO2peak), gross efficiency (GE), peak speed (Vpeak), and kinematics in skating were measured. Times on the last two uphill and two final flat sections were correlated to overall STT performance (r = ~−0.80, P < 0.001). For the selected uphill section, speed was correlated to cycle length (r = −0.75, P < 0.01) and the estimated work rate was approximately 160% of peak aerobic power. VO2peak, GE, Vpeak, and peak cycle length were all correlated to STT performance (r = ~−0.85, P < 0.001). More specifically, VO2peak and GE were correlated to the last two uphill and two final flat section times, whereas Vpeak and peak cycle length were correlated to times in all uphill, flat, and curved sections except for the initial section (r = ~−0.80, P < 0.01). Performances on uphill and flat terrain in the latter part were the most significant determinants of overall STT performance. Peak oxygen uptake, efficiency, peak speed, and peak cycle length were strongly correlated to overall STT performance, as well as to performance in different sections of the race

Forskningsetiske retningslinjer for samfunnsvitenskap og humaniora

Den nasjonale forskningsetiske komité for samfunnsvitenskap og humaniora (NESH) er et uavhengig og rådgivende organ, som har ansvar for å utarbeide nasjonale forskningsetiske retningslinjer. Den første utgaven av NESHs retningslinjer ble utgitt i 1993, og de har kommet i reviderte utgaver i 1999, 2006 og 2016. For mer om NESH og retningslinjene, se vedlegg. I denne utgaven har NESH valgt å fremheve og tydeliggjøre de grunnleggende forskningsetiske normene. Formålet er å fremheve NESHs retningslinjer som en selvstendig kilde til forskningsetisk refleksjon og kontinuering diskusjon i forskerfellesskapet. NESH har også presisert hvordan forskning i økende grad er under press, og hvordan ulike aktører som oppdragsgivere, finansiører og samarbeidspartnere har medansvar for å ivareta forskningsetikken. Videre er skillet mellom etikk og juss presisert for å tydeliggjøre grenseflatene mot henholdsvis gransking av vitenskapelig uredelighet og krav om rettsgrunnlag ved behandling av personopplysninger. Høsten 2020 ble det reviderte utkastet til nasjonale retningslinjer sendt på høring. NESH mottok over 60 innspill fra forskere, forskningsinstitusjoner og andre forskningsaktører. En arbeidsgruppe bestående av Elisabeth Staksrud (leder), Ivar Kolstad (nestleder) og Vidar Enebakk (sekretariatsleder) har gått gjennom alle innspill og utarbeidet forslag, som er grundig drøftet og vedtatt av alle medlemmene i komiteen.publishedVersio

Exploring gut microbiota in adult Atlantic salmon (Salmo salar L.): Associations with gut health and dietary prebiotics

Abstract Background The importance of the gut microbiota for physiological processes in mammals is well established, but the knowledge of their functional roles in fish is still limited. The aims of this study were to investigate associations between variation in taxonomical composition of the gut microbiota and gut health status in Atlantic salmon and to explore possible modulatory effects of dietary prebiotics in one net-pen farm in open water. The fish with initial mean body weight of around 240 g were fed diets based on the same basal composition, either without (Ref diet) or with (Test diet) yeast cell wall based-prebiotics, during the marine production phase from December to September the following year. Sampling was conducted at three sampling time points: January, April, and September, with average water temperature of 3.9 ℃, 3.4 ℃ and 9.6 ℃, respectively. Results As the fish progressed towards September, growth, brush border membrane enzyme activities, and the expression in the gut of most of the observed genes involved in immune (e.g., il8, cd4a, myd88, il1b, gilt, tgfb, cd8b and cd3), barrier (e.g., zo1, occludin, ecad, claudin25b and claudin15), and metabolism increased significantly. Lipid accumulation in pyloric enterocytes decreased remarkably, suggesting improvement of gut health condition. The growth of the fish did not differ between dietary treatments. Further, dietary prebiotics affected the gut health only marginally regardless of duration of administration. Regarding gut microbiota composition, a decrease in alpha diversity (Observed species, Pielou and Shannon) over time was observed, which was significantly associated with an increase in the relative abundance of genus Mycoplasma and decrease in 32 different taxa in genus level including lactic acid bacteria (LAB), such as Lactobacillus, Leuconostoc, and Lactococcus. This indicates that developmental stage of Atlantic salmon is a determinant for microbial composition. Multivariate association analysis revealed that the relative abundance of Mycoplasma was positively correlated with gut barrier gene expression, negatively correlated with plasma glucose levels, and that its relative abundance slightly increased by exposure to prebiotics. Furthermore, certain LAB (e.g., Leuconostoc), belonging to the core microbiota, showed a negative development with time, and significant associations with plasma nutrients levels (e.g., triglyceride and cholesterol) and gene expression related to gut immune and barrier function. Conclusions As Atlantic salmon grew older under large-scale, commercial farm settings, the Mycoplasma became more prominent with a concomitant decline in LAB. Mycoplasma abundance correlated positively with time and gut barrier genes, while LAB abundance negatively correlated to time. Dietary prebiotics affected gut health status only marginally

Kinematic and spatiotemporal gait characteristics in pregnant women with pelvic girdle pain, asymptomatic pregnant and non-pregnant women

Background Walking difficulties are common among pregnant women with pelvic girdle pain. This cross-sectional study investigated the influence of pelvic girdle pain, pregnancy and speed on spatiotemporal and trunk, pelvic and hip kinematics during gait in the 2nd trimester of pregnancy. Methods Three-dimensional gait analysis at self-selected speed was performed in 25 pregnant women with pelvic girdle pain, 24 asymptomatic pregnant and 24 non-pregnant women. Linear mixed models were used to investigate between-group differences in gait variables. Adjustment for gait speed was included in the analysis. Correlations between speed and fear of movement, disability and pain were examined using Spearman correlation coefficient (rs). Findings Pregnant women with pelvic girdle pain walked 18% slower (estimated marginal means (95% confidence intervals) 1.18 (1.22, 1.24) meter/s) compared to asymptomatic pregnant women (1.44 (1.38, 1.50) meter/s) (P < 0.001). Moreover, with longer double limb support (5%, P = 0.04), shorter contralateral step length (3%, P = 0.03) and more restricted pelvic and hip kinematics (0.001 ≤ P ≤ 0.01) adjusted for speed. Only stance, double limb support and thoracic rotation (0.001 ≤ P ≤ 0.04) differed between asymptomatic pregnant and non-pregnant women. Speed was negatively correlated with fear of movement (rs = −0.63, P = 0.01) and disability (rs = −0.46, P = 0.03) in the pelvic girdle pain group. Interpretation Gait is primarily influenced by pelvic girdle pain and less by pregnancy. Pregnant women with pelvic girdle pain walked slower and with a more rigid gait pattern compared to asymptomatic pregnant women, presumably related to altered load transfer. Our results may assist clinical evaluation of pelvic girdle pain, as well as direct future research

Trunk, pelvic and hip kinematics during the Stork test in pregnant women with pelvic girdle pain, asymptomatic pregnant and non-pregnant women

Background Pelvic girdle pain is prevalent during pregnancy, and women affected report weight-bearing activities to be their main disability. The Stork test is a commonly used single-leg-stance test. As clinicians report specific movement patterns in those with pelvic girdle pain, we aimed to investigate the influence of both pregnancy and pelvic girdle pain on performance of the Stork test. Methods In this cross-sectional study, 25 pregnant women with pelvic girdle pain, 23 asymptomatic pregnant and 24 asymptomatic non-pregnant women underwent three-dimensional kinematic analysis of the Stork test. Linear mixed models were used to investigate between-group differences in trunk, pelvic and hip kinematics during neutral stance, weight shift, leg lift and single leg stance. Findings Few and small significant between-group differences were found. Pregnant women with pelvic girdle pain had significantly less hip adduction during single leg stance compared to asymptomatic pregnant women (estimated marginal means (95% confidence intervals) -1.1° (−2.4°, 0.3°) and 1.0° (−0.4°, 2.4°), respectively; P = 0.03). Asymptomatic pregnant women had significantly less hip internal rotation compared to non-pregnant women 4.1° (1.6°, 6.7°) and 7.9° (5.4°, 10.4°), respectively (P = 0.04) and greater peak hip flexion angle of the lifted leg in single leg stance 80.4° (77.0°, 83.9°) and 74.1° (70.8°, 77.5°), respectively (P = 0.01). Variation in key kinematic variables was large across participants in all three groups. Interpretation Our findings indicate that trunk, pelvic and hip movements during the Stork test are not specific to pregnancy and/or pelvic girdle pain in the 2nd trimester. Instead, movement strategies appear unique to each individual