756 research outputs found
Skeletal Muscle Metabolism in Endurance Athletes with Near-Infrared Spectroscopy
. Purpose: To determine whether near-infrared spectroscopy (NIRS) measurements of muscle mitochondrial function could detect the expected differences between endurance-trained athletes (n = 8) and inactive subjects (n = 8). Methods: Muscle oxygen consumption (mV O 2 ) of the vastus lateralis was measured with continuous-wave NIRS using transient arterial occlusions. The recovery rate of mV O 2 after electrical stimulation was fit to an exponential curve, with the time constant (T c ) used as an index of mitochondrial capacity. Whole-body peak oxygen uptake was determined by indirect calorimetry during a continuous ramp protocol on a cycle ergometer. Results: Whole-body peak oxygen uptake values for endurance-trained and inactive controls were 73.5 T 9.1 and 33.7 T 5.9 mLIkg j1 Imin j1 , respectively (P G 0.001). The recovery rates of mV O 2 after exercise for endurance training were 18.4 T 3.2 and 18.8 T 2.5 s, whereas those for inactive controls were 32.4 T 5.2 and 34.9 T 5.9 s for the shallow and deep channels, respectively (P G 0.001 for comparison between groups). Resting mV O 2 was 0.52%Is j1 T 0.22%Is j1 for endurance athletes and 0.77%Is j1 T 0.82%Is j1 for inactive controls (P = 0.42). Conclusions: The recovery rates of mV O 2 after exercise in endurance athletes were almost twofold faster than inactive subjects measured with NIRS, consistent with previous studies using muscle biopsies and magnetic resonance spectroscopy. Our results support the use of NIRS measurements of the recovery of oxygen consumption to assess muscle oxidative capacity. Key Words: NIRS, MITOCHONDRIAL CAPACITY, ELECTRICAL STIMULATION, OXIDATIVE METABOLISM, ENDURANCE TRAINING, MAXIMAL OXYGEN UPTAKE, COMPETITIVE CYCLISTS O xidative metabolism is the primary method of energy production in skeletal muscle, and changes in oxidative muscle metabolism have been shown to be useful in understanding muscle function in both healthy and diseased conditions MATERIALS AND METHODS Subjects. Sixteen subjects (12 men and 4 women) were tested in this study. Subjects were selected to have either
Wellness and Multiple Sclerosis: The National MS Society Establishes a Wellness Research Working Group and Research Priorities
Background:
People with multiple sclerosis (MS) have identified “wellness” and associated behaviors as a high priority based on “social media listening” undertaken by the National MS Society (i.e. the Society). Objective:
The Society recently convened a group that consisted of researchers with experience in MS and wellness-related research, Society staff members, and an individual with MS for developing recommendations regarding a wellness research agenda. Method:
The members of the group engaged in focal reviews and discussions involving the state of science within three approaches for promoting wellness in MS, namely diet, exercise, and emotional wellness. Results:
That process informed a group-mediated activity for developing and prioritizing research goals for wellness in MS. This served as a background for articulating the mission and objectives of the Society’s Wellness Research Working Group. Conclusion:
The primary mission of the Wellness Research Working Group is the provision of scientific evidence supporting the application of lifestyle, behavioral, and psychosocial approaches for promoting optimal health of mind, body, and spirit (i.e. wellness) in people with MS as well as managing the disease and its consequences
The progenitor and early evolution of the Type IIb SN 2016gkg
We report initial observations and analysis on the Type IIb SN~2016gkg in the
nearby galaxy NGC~613. SN~2016gkg exhibited a clear double-peaked light curve
during its early evolution, as evidenced by our intensive photometric follow-up
campaign. SN~2016gkg shows strong similarities with other Type IIb SNe, in
particular with respect to the \he~emission features observed in both the
optical and near infrared. SN~2016gkg evolved faster than the prototypical
Type~IIb SN~1993J, with a decline similar to that of SN~2011dh after the first
peak. The analysis of archival {\it Hubble Space Telescope} images indicate a
pre-explosion source at SN~2016gkg's position, suggesting a progenitor star
with a mid F spectral type and initial mass \msun, depending on
the distance modulus adopted for NGC~613. Modeling the temperature evolution
within of explosion, we obtain a progenitor radius of
\rsun, smaller than that obtained from the analysis of the
pre-explosion images (\rsun).Comment: 7 pages, 5 figures. Submitted to ApJ Letter
Draft genome sequences of Pseudomonas fluorescens strains SF39a and SF4c, potential plant growth promotion and biocontrol agents
Pseudomonas fluorescens SF4c and SF39a, strains isolated from wheat rhizosphere, have potential applications in plant growth promotion and biocontrol of fungal diseases of crop plants. We report the draft genome sequences of SF4c and SF39a with estimated sizes of 6.5 Mb and 5.9 Mb, respectively.Fil: Ly, Lindsey K.. University of Massachussets; Estados UnidosFil: Underwood, Grace E.. University of Massachussets; Estados UnidosFil: McCully, Lucy M.. University of Massachussets; Estados UnidosFil: Bitzer, Adam S.. University of Massachussets; Estados UnidosFil: Godino, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Bucci, Vanni. University of Massachussets; Estados UnidosFil: Brigham, Christopher J.. University of Massachussets; Estados UnidosFil: Principe, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Fischer, Sonia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Silby, Mark W.. University of Massachussets; Estados Unido
Extensive HST Ultraviolet Spectra and Multi-wavelength Observations of SN 2014J in M82 Indicate Reddening and Circumstellar Scattering by Typical Dust
SN 2014J in M82 is the closest detected Type Ia supernova (SN Ia) in at least
28 years and perhaps in 410 years. Despite its small distance of 3.3 Mpc, SN
2014J is surprisingly faint, peaking at V = 10.6 mag, and assuming a typical SN
Ia luminosity, we infer an observed visual extinction of A_V = 2.0 +/- 0.1 mag.
But this picture, with R_V = 1.6 +/- 0.2, is too simple to account for all
observations. We combine 10 epochs (spanning a month) of HST/STIS ultraviolet
through near-infrared spectroscopy with HST/WFC3, KAIT, and FanCam photometry
from the optical to the infrared and 9 epochs of high-resolution TRES
spectroscopy to investigate the sources of extinction and reddening for SN
2014J. We argue that the wide range of observed properties for SN 2014J is
caused by a combination of dust reddening, likely originating in the
interstellar medium of M82, and scattering off circumstellar material. For this
model, roughly half of the extinction is caused by reddening from typical dust
(E(B-V ) = 0.45 mag and R_V = 2.6) and roughly half by scattering off LMC-like
dust in the circumstellar environment of SN 2014J.Comment: 17 pages (excluding references and tables), 15 figures, accepted to
MNRAS. A high-resolution HST image of SN 2014J in M82 is available upon
reques
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