261 research outputs found

    Aerodynamics Of Soccer Balls And Volleyballs

    Get PDF
    The purpose of this study was to investigate range, flight time, speed and trajectory of selected official soccer balls and volleyballs in a constant release angle (18 degree) shot by a ball gun with a hydraulic shooting steel leg mechanism in an indoor soccer hall. Five soccer balls (m=0.422 ± 0.010 kg, d=0.108 + 0.002 rn, p=(0.69 + 0.01) x 105 Nm-2) and five volleyballs (m=0.278 ± 0.006 kg, d=0.105 + 0.002 rn, p=(0.69 ±0.01) x 105 Nm-2) were used. Three speeds of the kicking steel leg were applied to the stationary and rotating balls with two constant angular velocities (45.6 and 65.0 radls). All shots of the balls were recorded with two JVC 707 5-VHS camcorders (50 Hz) for kinematic and kinetic motion analysis. An APAS performance analysis system was used for detailed 3D analysis of the release phase of the shot. The range of the ball was measured in x-z coordinates on the Astroturf ground. A Panasonic camcorder with timer was used to measure the flight time of the ball. A 3- way ANOVA was applied in order to study the differences of the balls and their behaviour in the placid air. The release velocities of the stationary soccer balls with three speed categories .were 18.8 + 0.1 ms·1, 23.1 ± 0.1 msand 26.5 ± 0.1 ms-1 and in volleyballs 20.5 ± 0.2 ms-I, 25.6 ± 0.2 ms-1 and 29.4 ± 0.2 ms-1, respectively. The range of the fastest shot off the soccer balls was on average 44.8 m with the lateral deviation of 3.3 degrees. The average range of the volleyballs in the fastest shots without spin was 45.2 m with the lateral deviation of 4.8 degrees. The average ground speeds in the fastest shots of the soccer ball and volleyball were 20.6 ms-1 and 24.7 ms-1, respectively. With the fastest spin and shot the range and deviation of soccer balls and volleyballs were 34.4 m and 38.6 m and 19.7 and 21.4 degrees, respectively. The main effects of the ball type, shot speed and spin were significant (

    Taxon abundance, diversity, co-occurrence and network analysis of the ruminal microbiota in response to dietary changes in dairy cows

    Get PDF
    We thank Mari Talvisilta and the staff in the metabolism unit at Natural Resources Institute Finland for technical support, care of experimental animals and assistance in sample collection. We thank Paula Lidauer for ruminal cannulation surgeries, Richard Hill from Aberystwyth University, UK for performing qPCR and Aurélie Bonin from Laboratoire d'Ecologie Alpine, CNRS, France for preparing archaea amplicon libraries for sequencing. Kevin J. Shingfield passed away before the submission of the final version of this manuscript. Ilma Tapio accepts responsibility for the integrity and validity of the data collected and analyzed. Funding: Study was funded by the Finnish Ministry of Agriculture and Forestry as part of the GreenDairy Project (Developing Genetic and Nutritional Tools to Mitigate the Environmental Impact of Milk Production; Project No. 2908234). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Genomewide transcriptome profiling of milk derived primary bovine mammary epithelial cells after pathogen challenge

    Get PDF
    A method was developed to collect and cultivate primary bovine mammary epithelial cells (pbMECs) from milk samples of healthy lactating cows. Cell cultures from ten Nordic Red cows were used in a pathogen challenge study with two common pathogens, Escherichia coli and Staphylococcus aureus. Transcriptomewide changes in gene expression were monitored at four time points after challenge. We present here preliminary results from two cows, showing that pathogen specific differences in gene expression can be detected in the pbMECs, reflecting differences in the immune responses triggered by each pathogen

    Oral Samples as Non-Invasive Proxies for Assessing the Composition of the Rumen Microbial Community

    Get PDF
    Microbial community analysis was carried out on ruminal digesta obtained directly via rumen fistula and buccal fluid, regurgitated digesta (bolus) and faeces of dairy cattle to assess if non-invasive samples could be used as proxies for ruminal digesta. Samples were collected from five cows receiving grass silage based diets containing no additional lipid or four different lipid supplements in a 5 x 5 Latin square design. Extracted DNA was analysed by qPCR and by sequencing 16S and 18S rRNA genes or the fungal ITS1 amplicons. Faeces contained few protozoa, and bacterial, fungal and archaeal communities were substantially different to ruminal digesta. Buccal and bolus samples gave much more similar profiles to ruminal digesta, although fewer archaea were detected in buccal and bolus samples. Bolus samples overall were most similar to ruminal samples. The differences between both buccal and bolus samples and ruminal digesta were consistent across all treatments. It can be concluded that either proxy sample type could be used as a predictor of the rumen microbial community, thereby enabling more convenient large-scale animal sampling for phenotyping and possible use in future animal breeding programs aimed at selecting cattle with a lower environmental footprint

    The effect of dietary rumen-protected trans-10,cis-12 conjugated linoleic acid or a milk fat-depressing diet on energy metabolism, inflammation, and oxidative stress of dairy cows in early lactation

    Get PDF
    The objective of this study was to determine the effects of milk fat depression induced by supplementing conjugated linoleic acid (CLA; trans-10,cis-12 and cis-9,trans-11 CLA) or feeding a higher starch and oil-containing diet (HSO) on metabolic changes in dairy cows after calving. The main hypothesis was that the 2 strategies to decrease milk fat yield could have different effects on performance, energy balance (EB), and inflammatory status in early lactation. Thirty-three Nordic Red dairy cows were used in a randomized block design from 1 to 112 d of lactation and fed one of the following treatments: control (CON), CLA-supplemented diet, or HSO diet. Dry matter intake and milk yield were measured daily whereas milk composition was measured weekly throughout the experiment. Nutrient digestibility, EB, and plasma hormones and metabolites were measured at 3, 7, 11, and 15 wk of lactation in respiration chambers. The HSO diet led to lower intakes of dry matter, neutral detergent fiber, and gross energy compared with CON and CLA diets. The CLA diet and especially the HSO diet resulted in lower energy-corrected milk yield during the first 7 wk of lactation than those fed CON. The EB was numerically higher for HSO and CLA diets compared with CON at wk 3 and 7. Plasma glucose concentration was higher by the CLA diet at wk 3 and by the HSO diet from wk 3 to 15 compared with CON. Plasma nonesterified fatty acids were higher at wk 3 in the CON group (indicating more lipid mobilization) but decreased thereafter to similar levels with the other groups. The HSO-fed cows had higher plasma ceruloplasmin, paraoxonase, and total bilirubin concentrations in the entire experiment and showed the highest levels of reactive oxygen metabolites. These results suggest an increased inflammatory and oxidative stress state in the HSO cows and probably different regulation of the innate immune system. This study provides evidence that milk fat depression induced by feeding HSO (as well as CLA) decreased milk fat secretion and improved EB compared with CON in early lactation. The increase in plasma glucose and paraoxonase levels with the HSO diet may imply a better ability of the liver to cope with the metabolic demand after parturition. However, the negative effect of HSO on feed intake, and the indication of increased inflammatory and oxidative stress warrant further studies before the HSO feeding strategy could be supported as an alternative to improve EB in early lactation
    corecore