1,306 research outputs found

    Combining Microdialysis and Near-Infrared Spectroscopy for Studying Effects of Low-Load Repetitive Work on the Intramuscular Chemistry in Trapezius Myalgia

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    Epidemiological research provides strong evidence for a link between repetitive work (RW) and the development of chronic trapezius myalgia (TM). The aims were to further elucidate if an accumulation of sensitising substances or impaired oxygenation is evident in painful muscles during RW. Females with TM (n = 14) were studied during rest, 30 minutes RW and 60 minutes recovery. Microdialysate samples were obtained to determine changes in intramuscular microdialysate (IMMD) [glutamate], [PGE2], [lactate], and [pyruvate] (i.e., [concentration]) relative to work. Muscle oxygenation (%StO2) was assessed using near-infrared spectroscopy. During work, all investigated substances, except PGE2, increased significantly: [glutamate] (54%, P < .0001), [lactate] (26%, P < .005), [pyruvate] (19%, P < .0001), while the %StO2 decreased (P < .05). During recovery [PGE2] decreased (P < .005), [lactate] remained increased (P < .001), [pyruvate] increased progressively (P < .0001), and %StO2 had returned to baseline. Changes in substance concentrations and oxygenation in response to work indicate normal increase in metabolism but no ongoing inflammation in subjects with TM

    Fasting leptin is a metabolic determinant of food reward in overweight and obese individuals during chronic aerobic exercise training

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    Changes in food reward have been implicated in exercise-induced compensatory eating behaviour. However, the underlying mechanisms of food reward, and the physiological correlates of exercise-induced changes in food reward, are unknown. Methods. Forty-six overweight and obese individuals completed 12 weeks of aerobic exercise. Body composition, food intake, and fasting metabolic-related hormones were measured at baseline, week six, and postintervention. On separate days, the reward value of high-and-low-fat food (explicit liking and implicit wanting) was also assessed at baseline, week six, and postintervention. Results. Following the intervention, FM, FFM, and V O 2 peak improved significantly, while fasting leptin decreased. However, food intake or reward did not change significantly. Cross-sectional analyses indicated that FM (P = 0.022) and FFM (P = 0.046) were associated with explicit liking for high-fat food, but implicit wanting was associated with FM only (P = 0.005). Fasting leptin was associated with liking (P = 0.023) and wanting (P = 0.021) for high-fat food. Furthermore, a greater exercise-induced decline in fasting leptin was associated with increased liking (P = 0.018). Conclusion. These data indicate that food reward has a number of physiological correlates. In particular, fasting leptin appears to play an active role in mediating food reward during exercise-induced weight loss. © 2014 Mark Hopkins et al

    Reducing Cyclic Dispersion in Autoignition Combustion by Controlling Fuel Injection Timing

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    Abstract-Model-based control design for reducing the cyclic variability (CV) in lean autoignition combustion is presented. The design is based on a recently proposed control-oriented model that captures the experimental observations of CV. The model is extended here to include the effect of the fuel injection timing, which is an effective way of influencing the combustion phasing. This model is only stable for certain amounts of residual gas. For high amounts, runaway behavior occurs where the combustion phasing occurs increasingly earlier. For low amounts, a cascade of period-doubling bifurcations occurs leading to chaotic behavior. This complex dynamics is further complicated with significant levels of noise, which creates a challenging control problem. With the aim at controllers feasible for on-board implementation, a proportional controller and a reduced-order state feedback controller are designed, with feedback from the combustion phasing. The controllers are evaluated by simulations and the results show that the CV can be significantly reduced, in an operating point of engine speed and load, for a wide range of residual gas fractions

    Reducing Cyclic Dispersion in Autoignition Combustion by Controlling Fuel Injection Timing

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    Abstract-Model-based control design for reducing the cyclic variability (CV) in lean autoignition combustion is presented. The design is based on a recently proposed control-oriented model that captures the experimental observations of CV. The model is extended here to include the effect of the fuel injection timing, which is an effective way of influencing the combustion phasing. This model is only stable for certain amounts of residual gas. For high amounts, runaway behavior occurs where the combustion phasing occurs increasingly earlier. For low amounts, a cascade of period-doubling bifurcations occurs leading to chaotic behavior. This complex dynamics is further complicated with significant levels of noise, which creates a challenging control problem. With the aim at controllers feasible for on-board implementation, a proportional controller and a reduced-order state feedback controller are designed, with feedback from the combustion phasing. The controllers are evaluated by simulations and the results show that the CV can be significantly reduced, in an operating point of engine speed and load, for a wide range of residual gas fractions

    UK Criteria for Uterus Transplantation: A Review

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    Absolute Uterine Factor Infertility (AUFI) is the final hurdle for assisted reproductive treatments. Uterus transplant trials are happening worldwide; in order to advance the debate around uterine transplantation (UTx) this article considers selection criteria for clinical trials from a UK perspective and makes recommendations for future selection criteria for UTx treatment. Recommendations advanced include the use of donor eggs, access for single women and women in same-sex relationships, prohibiting participation of women who are already mothers, and a preference for deceased donors and bioengineered uteri. With UTx treatment on the horizon it is important to proactively consider future selection criteria

    Fuel governor augmented control of recompression HCCI combustion during large load transients

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    Abstract-A control strategy designed to track desired combustion phasing for a homogeneous charge compression ignition (HCCI) engine during large load transitions is presented in this work. Three inputs are controlled, namely valve timings, fuel injection amount and fuel injection timing. The valve and fuel injection timings are manipulated to track combustion phasing using a mid-ranging control strategy. A fuel governor is then added on to the compensated system to modify the fuel injection amount by enforcing pointwise-in-time actuator constraints. The fuel governor is shown to improve the transient response of combustion phasing and load during large load transitions, when the possibility of future constraint violations exists. The use of the fuel governor during large load reductions can prevent engine misfire. Moreover, the fuel governor strategy simplifies the overall controller design by decoupling the phasing controller from the constraint enforcing mechanism. System complexity is reduced by approximating the nonlinear fuel governor as a set of linear algebraic expressions. This is solved with very little computational overhead and without incurring a significant loss in performance, as presented in simulations

    Comprehensive genetic and epigenetic analysis of sporadic meningioma for macro-mutations on 22q and micro-mutations within the NF2 locus

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    BACKGROUND: Meningiomas are the most common intracranial neoplasias, representing a clinically and histopathologically heterogeneous group of tumors. The neurofibromatosis type 2 (NF2) tumor suppressor is the only gene known to be frequently involved in early development of meningiomas. The objective of this study was to identify genetic and/or epigenetic factors contributing to the development of these tumors. A large set of sporadic meningiomas were analyzed for presence of 22q macro-mutations using array-CGH in order to identify tumors carrying gene dosage aberrations not encompassing NF2. The NF2 locus was also comprehensively studied for point mutations within coding and conserved non-coding sequences. Furthermore, CpG methylation within the NF2 promoter region was thoroughly analyzed. RESULTS: Monosomy 22 was the predominant finding, detected in 47% of meningiomas. Thirteen percent of the tumors contained interstitial/terminal deletions and gains, present singly or in combinations. We defined at least two minimal overlapping regions outside the NF2 locus that are small enough (~550 kb and ~250 kb) to allow analysis of a limited number of candidate genes. Bialleinactivationo the NF2 gne was detected in 36% of meningiomas. Among the monosomy 22 cases, no additional NF2 mutations could be identified in 35% (17 out of 49) of tumors. Furthermore, the majority of tumors (9 out of 12) with interstitial/terminal deletions did not have any detectable NF2 mutations. Methylation within the NF2 promoter region was only identified at a single CpG site in one tumor sample. CONCLUSION: We confirmed previous findings of pronounced differences in mutation frequency between different histopathological subtypes. There is a higher frequency of biallelic NF2 inactivation in fibroblastic (52%) compared to meningothelial (18%) tumors. The presence of macro-mutations on 22q also shows marked differences between fibroblastic (86%) and meningothelial (39%) subtypes. Thus, inactivation of NF2, often combined with the presence of macro-mutation on 22q, is likely not as important for the development of the meningothelial subtype, as opposed to the fibroblastic form. Analysis of 40 CpG sites distributed within 750 bp of the promoter region suggests that NF2 promoter methylation does not play a major role in meningioma development

    The rp-process and new measurements of beta-delayed proton decay of light Ag and Cd isotopes

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    Recent network calculations suggest that a high temperature rp-process could explain the abundances of light Mo and Ru isotopes, which have long challenged models of p-process nuclide production. Important ingredients to network calculations involving unstable nuclei near and at the proton drip line are β\beta-halflives and decay modes, i.e., whether or not β\beta-delayed proton decay takes place. Of particular importance to these network calculation are the proton-rich isotopes 96^{96}Ag, 98^{98}Ag, 96^{96}Cd and 98^{98}Cd. We report on recent measurements of β\beta-delayed proton branching ratios for 96^{96}Ag, 98^{98}Ag, and 98^{98}Cd at the on-line mass separator at GSI.Comment: 4 pages, uses espcrc1.sty. Proceedings of the 4th International Symposium Nuclei in the Cosmos, June 1996, Notre Dame/IN, USA, Ed. M. Wiescher, to be published in Nucl.Phys.A. Also available at ftp://ftp.physics.ohio-state.edu/pub/nucex/nic96-gs

    Fragmentation of exotic oxygen isotopes

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    Abrasion-ablation models and the empirical EPAX parametrization of projectile fragmentation are described. Their cross section predictions are compared to recent data of the fragmentation of secondary beams of neutron-rich, unstable 19,20,21O isotopes at beam energies near 600 MeV/nucleon as well as data for stable 17,18O beams
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