799 research outputs found
Impact of physical activity, sedentary behaviour and muscle strength on bone stiffness in 2-10-year-old children-cross-sectional results from the IDEFICS study
Background: Physical activity (PA), weight-bearing exercises (WBE) and muscle strength contribute to skeletal development, while sedentary behaviour (SB) adversely affects bone health. Previous studies examined the isolated effect of PA, SB or muscle strength on bone health, which was usually assessed by x-ray methods, in children. Little is known about the combined effects of these factors on bone stiffness (SI) assessed by quantitative ultrasound. We investigated the joint association of PA, SB and muscle strength on SI in children.
Methods: In 1512 preschool (2- < 6 years) and 2953 school children (6-10 years), data on calcaneal SI as well as on accelerometer-based sedentary time (SED), light (LPA), moderate (MPA) and vigorous PA (VPA) were available. Parents reported sports (WBE versus no WBE), leisure time PA and screen time of their children. Jumping distance and handgrip strength served as indicators for muscle strength. The association of PA, SB and muscle strength with SI was estimated by multivariate linear regression, stratified by age group. Models were adjusted for age, sex, country, fat-free mass, daylight duration, consumption of dairy products and PA, or respectively SB.
Results: Mean SI was similar in preschool (79.5 +/- 15.0) and school children (81.3 +/- 12.1). In both age groups, an additional 10 min/day in MPA or VPA increased the SI on average by 1 or 2 %, respectively (p = .05). The negative association of SED with SI decreased after controlling for MVPA. LPA was not associated with SI. Furthermore, participation in WBE led to a 3 and 2 % higher SI in preschool (p = 0.003) and school children (p < .001), respectively. Although muscle strength significantly contributed to SI, it did not affect the associations of PA with SI. In contrast to objectively assessed PA, reported leisure time PA and screen time showed no remarkable association with SI.
Conclusion: This study suggests that already an additional 10 min/day of MPA or VPA or the participation in WBE may result in a relevant increase in SI in children, taking muscle strength and SB into account. Our results support the importance of assessing accelerometer-based PA in large-scale studies. This may be important when deriving dose-response relationships between PA and bone health in children
FLEXSELECT: counter-herding device to reduce bycatch in crustacean trawl fisheries
FLEXSELECT is a simple counter-herding device which aims at reducing the bycatch of fish by scaring them away from the trawl path without affecting the catches of the target species. FLEXSELECT was tested in the Norway lobster (Nephrops norvegicus) directed trawl fishery, as this includes bycatch of both roundfish and flatfish. Length-based data were collected for Nephrops, four roundfish species (cod, haddock, whiting and hake) and two flatfish species (plaice and lemon sole) and length-based catch comparisons performed. No significant effect on the target species, Nephrops, was detected, whereas a reduction of 39% (CI: 29-46 %) was obtained for the overall number of fish. Catches of all the six fish species examined were significantly reduced by FLEXSELECT, with the efficiency varying considerably among species and over length classes. No significant diel differences were found for either roundfish or flatfish species. FLEXSELECT prevents bycatch species from interacting with the trawl, thus most likely enhancing their survival and fitness. Moreover, its fast attachment system makes FLEXSELECT a flexible tool, adaptable to different fisheries and catch goals.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Assessing the Efficacy of Nano- and Micro-Sized Magnetic Particles as Contrast Agents for MRI Cell Tracking
Iron-oxide based contrast agents play an important role in magnetic resonance imaging (MRI) of labelled cells in vivo. Currently, a wide range of such contrast agents is available with sizes varying from several nanometers up to a few micrometers and consisting of single or multiple magnetic cores. Here, we evaluate the effectiveness of these different particles for labelling and imaging stem cells, using a mouse mesenchymal stem cell line to investigate intracellular uptake, retention and processing of nano- and microsized contrast agents. The effect of intracellular confinement on transverse relaxivity was measured by MRI at 7 T and in compliance with the principles of the ‘3Rs’, the suitability of the contrast agents for MR-based cell tracking in vivo was tested using a chick embryo model. We show that for all particles tested, relaxivity was markedly reduced following cellular internalisation, indicating that contrast agent relaxivity in colloidal suspension does not accurately predict performance in MR-based cell tracking studies. Using a bimodal imaging approach comprising fluorescence and MRI, we demonstrate that labelled MSC remain viable following in vivo transplantation and can be tracked effectively using MRI. Importantly, our data suggest that larger particles might confer advantages for longer-term imaging
Analysis of Barriers to the Development of Industrial Internet of Things Technology and Ways to Overcome Them
The development of the digital economy requires the compilation of a roadmap for the development of all the end-to-end technologies included in the cluster of technologies that need to be developed to a new level. At the first stage, anticipating decisions on state financing of this cluster, a list of critical end-to-end technologies is compiled. The second step is the preparation of roadmaps for each of the selected critical technologies. As a rule, many experts are involved in drawing up roadmaps, including foreign experts. As a rule, the team of such experts is headed by an organization that has received instructions to develop a roadmap on a competitive basis. Of course, not all the wishes of all experts are taken into account by such an organization; therefore, there may be alternative opinions and alternative roadmaps, or additions to the developed roadmaps. If the roadmap developed by the governing organization is approved, alternative documents are only of perhaps scientific interest. If the roadmap developed by the core team of experts is not approved due to its insufficient completeness, the decision seems to be postponed, and the specified roadmap should be corrected by adding information from alternative documents, which, of course, should be done taking into account the opinion of all experts in the field. Since the approved roadmap for the "Industrial Internet of Things" direction does not yet exist, the authors consider it useful to present their position on this issue
Physical and chemical optimisation of the seedball technology addressing pearl millet under Sahelian conditions
This study deals with the development of the seedball technology in particular for dry sowing under Sahelian conditions and pearl millet as crop. At first, our participatory evaluation in Senegal showed that (i) local materials needed for seedball production are locally available, (ii) the technology conforms to the existing management systems in the Sahel, and (iii) socio-economic conditions do not hinder seedball adoption. Afterwards, seedball was mechanically and chemically optimised. Pearl millet seedlings derived from the seedball variants were grown and compared to the control under greenhouse conditions. Our results showed that the combination of 80 g sand + 50 g loam + 25 ml water is the standard seedball dough, which produces about ten 2 cm diameter-sized seedballs. Either 1 g NPK fertiliser or 3 g wood ash can be added as nutrient additive to enhance early biomass of pearl millet seedlings. Ammonium fertiliser, urea and gum arabic as seedball components hampered seedlings emergence. Seedball + 3 g wood ash and seedball + 1 g NPK-treatments enhanced shoot biomass by 60 % and 75 %, root biomass by 36 % and 94 %, and root length density by 14 % and 28 %, respectively, relative to the control. Shoot nutrient content was not greatly influenced by treatment. However, multiplying biomass yield with nutrient content indicates that nutrient extraction was higher in nutrient-amended seedballs. On-station field tests in Senegal showed over 95 % emergence under real Sahelian conditions. Since early seedlings enhancement is decisive for pearl millet panicle yield under the Sahelian conditions, on-farm trials in the Sahel are recommended
Myopathic lamin mutations impair nuclear stability in cells and tissue and disrupt nucleo-cytoskeletal coupling
Lamins are intermediate filament proteins that assemble into a meshwork underneath the inner nuclear membrane, the nuclear lamina. Mutations in the LMNA gene, encoding lamins A and C, cause a variety of diseases collectively called laminopathies. The disease mechanism for these diverse conditions is not well understood. Since lamins A and C are fundamental determinants of nuclear structure and stability, we tested whether defects in nuclear mechanics could contribute to the disease development, especially in laminopathies affecting mechanically stressed tissue such as muscle. Using skin fibroblasts from laminopathy patients and lamin A/C-deficient mouse embryonic fibroblasts stably expressing a broad panel of laminopathic lamin A mutations, we found that several mutations associated with muscular dystrophy and dilated cardiomyopathy resulted in more deformable nuclei; in contrast, lamin mutants responsible for diseases without muscular phenotypes did not alter nuclear deformability. We confirmed our results in intact muscle tissue, demonstrating that nuclei of transgenic Drosophila melanogaster muscle expressing myopathic lamin mutations deformed more under applied strain than controls. In vivo and in vitro studies indicated that the loss of nuclear stiffness resulted from impaired assembly of mutant lamins into the nuclear lamina. Although only a subset of lamin mutations associated with muscular diseases caused increased nuclear deformability, almost all mutations tested had defects in force transmission between the nucleus and cytoskeleton. In conclusion, our results indicate that although defective nuclear stability may play a role in the development of muscle diseases, other factors, such as impaired nucleo-cytoskeletal coupling, likely contribute to the muscle phenotyp
Saatkugeln als Managementoption zur Verbesserung des Auflaufverhaltens von Perlhirse (Pennisetum glaucum) auf sandigen Böden im Sahel
Für den Perlhirseanbau im Sahel sind die frühen Vegetationsstadien von entscheidender Bedeutung. Die Saatkugeltechnologie kann das Auflaufverhalten und die Biomasseentwicklung in dieser Zeitspanne durch Nährstoffadditive (Holzasche, Mineraldünger) verbessern
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