728 research outputs found
A combination of cherry juice and cold water immersion does not enhance marathon recovery compared to either treatment in isolation: a randomized placebo-controlled trial
Purpose: Cherry juice (CJ) and cold water immersion (CWI) are both effective recovery strategies following strenuous endurance exercise. However, athletes routinely combine recovery interventions and less is known about the impact of a combined CJ and CWI protocol. Therefore, this study investigated the effects of combining CWI and CJ (a “cocktail” (CT)) on inflammation and muscle damage following a marathon.
Methods: A total 39 endurance trained males were randomly assigned to a placebo (PL), CWI, CJ, or CT group before completing a trail marathon run. Muscle damage (creatine kinase (CK)), muscle function (maximal voluntary isometric contraction (MVIC)), and inflammation (interleukin-6 (IL-6); C-reactive protein (CRP)) were measured at baseline, immediately after marathon (only IL-6), 24 h, and 48 h after marathon.
Results: There were no statistically significant differences between groups and no group × time interaction effects for any of the dependent variables. Confidence intervals (CI) illustrated that CT had unclear effects on inflammation (IL-6; CRP) and MVIC, but may have increased CK to a greater extent than PL and CJ conditions.
Conclusion: There is no evidence of an additive effect of CJ and CWI when the treatments are used in conjunction with each other. On the contrary, combining CJ and CWI may result in slightly increased circulating CK
Classical-quantum correspondence in atomic ionization by midinfrared pulses: Multiple peak and interference structures
Atomic ionization by strong and ultrashort laser pulses with frequencies in the midinfrared spectral region have revealed novel features such as the low-energy structures. We have performed fully three-dimensional quantum dynamical as well as classical trajectory Monte Carlo simulations for pulses with wavelengths from λ=2000 to 6000 nm. Furthermore, we apply distorted-wave quantum approximations. This allows to explore the quantum-classical correspondence as well as the (non) perturbative character of the ionization dynamics driven by long-wavelength pulses. We observe surprisingly rich structures in the differential energy and angular momentum distribution which sensitively depend on λ, the pulse duration τp, and the carrier-envelope phase ϕCEP
Accessibility-based reranking in multimedia search engines
Traditional multimedia search engines retrieve results based mostly on the query submitted by the user, or using a log of previous searches to provide personalized results, while not considering the accessibility of the results for users with vision or other types of impairments. In this paper, a novel approach is presented which incorporates the accessibility of images for users with various vision impairments, such as color blindness, cataract and glaucoma, in order to rerank the results of an image search engine. The accessibility of individual images is measured through the use of vision simulation filters. Multi-objective optimization techniques utilizing the image accessibility scores are used to handle users with multiple vision impairments, while the impairment profile of a specific user is used to select one from the Pareto-optimal solutions. The proposed approach has been tested with two image datasets, using both simulated and real impaired users, and the results verify its applicability. Although the proposed method has been used for vision accessibility-based reranking, it can also be extended for other types of personalization context
Fatal venous air embolism in swine during surgical procedure
Η εμβολή με αέρα της φλεβικής κυκλοφορίας είναι ένα σχετικά σπάνιο γεγονός που μπορεί να συμβεί τόσο κατάτην εκτέλεση απλών χειρουργικών χειρισμών όσο και κατά τη διάρκεια μεγάλων χειρουργικών επεμβάσεων. Αν και υπάρχειπληθώρα βιβλιογραφικών αναφορών για τον άνθρωπο, η αναφορά περιστατικών σε ζώα είναι περιορισμένη. Περιγράφεται περιστατικόφλεβικής εμβολής με αέρα, που παρατηρήθηκε κατά τη διάρκεια χειρουργικής επέμβασης, για την τοποθέτηση μοσχεύματοςαπό πολυτετραφλουοροαιθυλένιο μεταξύ κοινής καρωτίδας και έξω σφαγιτιδας φλέβας σε χοίρο. Πριν και μετά τηντοποθέτηση του μοσχεύματος πραγματοποιήθηκε λήψη μετρήσεων της ενδοαγγειακής πίεσης και των μεταβολών της διαμέτρουτης έξω σφαγιτιδας φλέβας, κεντρικά και περιφερικά της αναστόμωσης του μοσχεύματος, καθώς και μετρήσεις των μεταβολώντης ροής τόσο στην κοινή καρωτίδα όσο και στην έξω σφαγιτιδα φλέβα, κεντρικά και περιφερικά των αντίστοιχων αναστομώσεων.Το ζώο παρέμενε σταθερό αιμοδυναμικά για δυο ώρες και σαράντα λεπτά, οπότε αιφνιδίως παρατηρήθηκε ραγδαία πτώσητου κορεσμού του αίματος σε οξυγόνομε ταυτόχρονη μείωση της καρδιακής συχνότητας. Παρά τους χειρισμούς που έγιναν από τη χειρουργική ομάδα, μετά από δέκα λεπτά το ζώο κατέληξε. Κατά τη νεκροτομική εξέταση παρατηρήθηκε συγκέντρωση μεγάλης ποσότητας αέρα στη δεξιά καρδιά, στην πρόσθια και την οπίσθια κοίλη φλέβα, στην πνευμονική αρτηρία, καθώς και στις στεφανιαίες αρτηρίες. Παρόλο που πιθανολογείται ότι η είσοδος του αέρα έγινε από την αναισθητική μηχανή ή το σημείο της αναστόμωσης, ο τρόπος εισόδου παραμένει άγνωστος.Air embolism can occur after minor invasive procedures, as well as during major surgical operations. Reports of air embolism cases in veterinary literature are not very often, although it is considered that it happens more often than it is recognized. During a surgical procedure in swine, for the creation of a fistula of PTFE graft between the right common carotid artery and the right jugular vein under general anaesthesia, the animal died due to massive venous air embolism. Although it is supposed that the air was possibly inserted through the anaesthetic machine or through the anastomosis, the exact mechanism of the air insertion remains unknown
Low-energy peak structure in strong-field ionization by mid-infrared laser-pulses: two-dimensional focusing by the atomic potential
We analyze the formation of the low-energy structure (LES) in above-threshold
ionization spectra first observed by Quan et al.\ \cite{quan09} and Blaga et
al.\ \cite{blaga09} using both quasi-classical and quantum approaches. We show
this structure to be largely classical in origin resulting from a
two-dimensional focusing in the energy-angular momentum plane of the
strong-field dynamics in the presence of the atomic potential. The peak at low
energy is strongly correlated with high angular momenta of the photoelectrons.
Quantum simulations confirm this scenario. Resulting parameter dependences
agree with experimental findings \cite{quan09,blaga09} and, in part, with other
simulations \cite{liu10,yan10,kast11}.Comment: 12 pages, 6 figure
Subependymal Zone-Derived Oligodendroblasts Respond to Focal Demyelination but Fail to Generate Myelin in Young and Aged Mice
wo populations of oligodendrogenic progenitors co-exist within the corpus callosum (CC) of the adult mouse. Local, parenchymal oligodendrocyte progenitor cells (pOPCs) and progenitors generated in the subependymal zone (SEZ) cytogenic niche. pOPCs are committed perinatally and retain their numbers through self-renewing divisions, while SEZ-derived cells are relatively “young,” being constantly born from neural stem cells. We compared the behavior of these populations, labeling SEZ-derived cells using hGFAP:Cre mice, within the homeostatic and regenerating CC of the young-adult and aging brain. We found that SEZ-derived oligodendroglial progenitors have limited self-renewing potential and are therefore not bona fide OPCs but rather “oligodendroblasts” more similar to the neuroblasts of the neurogenic output of the SEZ. In the aged CC their mitotic activity is much reduced, although they still act as a “fast-response element” to focal demyelination. In contrast to pOPCs, they fail to generate mature myelinating oligodendrocytes at all ages studied.This work was supported by a grant from the Biotechnology and Biological Sciences Research Council (UK) ( BB/I013210/1 ) to R.F. and I.K
Utilising carbon dioxide for transport fuels : the economic and environmental sustainability of different Fischer-Tropsch process designs
Producing fuels and chemicals from carbon dioxide (CO2) could reduce our dependence on fossil resources and help towards climate change mitigation. This study evaluates the sustainability of utilising CO2 for production of transportation fuels. The CO2 feedstock is sourced from anaerobic digestion of sewage sludge and the fuels are produced in the Fischer-Tropsch (FT) process. Using life cycle assessment, life cycle costing and profitability analysis, the study considers four different process designs and a range of plant capacities to explore the effect of the economies of scale. For large-scale plants (1,670 t/day), the FT fuels outperform fossil diesel in all environmental impacts across all the designs, with several impacts being net-negative. The only exceptions are ozone depletion, for which fossil diesel is the best option, and global warming potential (GWP), which is lower for fossil diesel for some process designs. Optimising the systems reduces the GWP of FT fuels in the best case by 70% below that of fossil diesel. Assuming a replacement of 9.75–12.4% of fossil diesel consumed in the UK by 2,032, as stipulated by policy, would avoid 2–8 Mt of CO2 eq./yr, equivalent to 2–8% of annual emissions from transportation. However, these fuels are not economically viable and matching diesel pump price would require subsidies of 35–79% per litre. Optimising production yields would allow decreasing the subsidies to 8%. Future research should be aimed at technology improvements to optimise these systems as well as evaluating different policy mechanisms needed to stimulate markets for CO2-derived fuels
Stochastic Models for Solar Power
International audienceIn this work we develop a stochastic model for the solar power at the surface of the earth. We combine a deterministic model of the clear sky irradiance with a stochastic model for the so-called clear sky index to obtain a stochastic model for the actual irradiance hitting the surface of the earth. Our clear sky index model is a 4-state semi-Markov process where state durations and clear sky index values in each state have phase-type distributions. We use per-minute solar irradiance data to tune the model, hence we are able to capture small time scales fluctuations. We compare our model with the on-off power source model developed by Miozzo et al. (2014) for the power generated by photovoltaic panels, and to a modified version that we propose. In our on-off model the output current is frequently resampled instead of being a constant during the duration of the " on " state. Computing the autocorrelation functions for all proposed models, we find that the irradiance model surpasses the on-off models and it is able to capture the multiscale correlations that are inherently present in the solar irradiance. The power spectrum density of generated trajectories matches closely that of measurements. We believe our irradiance model can be used not only in the mathematical analysis of energy harvesting systems but also in their simulation
Linking Auxin with Photosynthetic Rate via Leaf Venation
International audienceLand plants lose vast quantities of water to the atmosphere during photosynthetic gas exchange. In angiosperms, a complex network of veins irrigates the leaf, and it is widely held that the density and placement of these veins determines maximum leaf hydraulic capacity and thus maximum photosynthetic rate. This theory is largely based on interspecific comparisons and has never been tested using vein mutants to examine the specific impact of leaf vein morphology on plant water relations. Here we characterize mutants at the Crispoid (Crd) locus in pea (Pisum sativum), which have altered auxin homeostasis and activity in developing leaves, as well as reduced leaf vein density and aberrant placement of free-ending veinlets. This altered vein phenotype in crd mutant plants results in a significant reduction in leaf hydraulic conductance and leaf gas exchange. We find Crispoid to be a member of the YUCCA family of auxin biosynthetic genes. Our results link auxin biosynthesis with maximum photosynthetic rate through leaf venation and substantiate the theory that an increase in the density of leaf veins coupled with their efficient placement can drive increases in leaf photosynthetic capacity
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