1,136 research outputs found
Effects of Thyrotoxicosis on Mitochondrial Enzymes of Rat Soleus
Cytochrome oxidase, glycerol-3-phosphate dehydrogenase, and succinate dehydrogenase were measured in mitochondrial fractions obtained from rat soleus muscle of control and 8 week T3 + T4 treated animals. Under these conditions of prolonged treatment, there is a five-fold increase in the specific activities of both cytochrome oxidase and glycerols-3-phosphate dehydrogenase. Significant increases in total cellular mitochondrial content and enzyme activities were observed in T3 + T4 treated animals as compared to controls. These results indicate that thyrotoxicosis can induce selective changes in mitochondrial enzymes in slow twitch red (Type I) muscle fibers
Good Limestone is Pure and Fine
You can\u27t judge the purity of the limestone you buy by simply looking at a sample. But here\u27s how you can
Skeletal Muscle PGC-1β Signaling is Sufficient to Drive an Endurance Exercise Phenotype and to Counteract Components of Detraining in Mice
Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and -1β serve as master transcriptional regulators of muscle mitochondrial functional capacity and are capable of enhancing muscle endurance when overexpressed in mice. We sought to determine whether muscle-specific transgenic overexpression of PGC-1β affects the detraining response following endurance training. First, we established and validated a mouse exercise-training-detraining protocol. Second, using multiple physiological and gene expression end points, we found that PGC-1β overexpression in skeletal muscle of sedentary mice fully recapitulated the training response. Lastly, PGC-1β overexpression during the detraining period resulted in partial prevention of the detraining response. Specifically, an increase in the plateau at which O2 uptake (V̇o2) did not change from baseline with increasing treadmill speed [peak V̇o2 (ΔV̇o2max)] was maintained in trained mice with PGC-1β overexpression in muscle 6 wk after cessation of training. However, other detraining responses, including changes in running performance and in situ half relaxation time (a measure of contractility), were not affected by PGC-1β overexpression. We conclude that while activation of muscle PGC-1β is sufficient to drive the complete endurance phenotype in sedentary mice, it only partially prevents the detraining response following exercise training, suggesting that the process of endurance detraining involves mechanisms beyond the reversal of muscle autonomous mechanisms involved in endurance fitness. In addition, the protocol described here should be useful for assessing early-stage proof-of-concept interventions in preclinical models of muscle disuse atrophy
Assembly and use of new task rules in fronto-parietal cortex
Severe capacity limits, closely associated with fluid intelligence, arise in learning and use of new task rules. We used fMRI to investigate these limits in a series of multirule tasks involving different stimuli, rules, and response keys. Data were analyzed both during presentation of instructions and during later task execution. Between tasks, we manipulated the number of rules specified in task instructions, and within tasks, we manipulated the number of rules operative in each trial block. Replicating previous results, rule failures were strongly predicted by fluid intelligence and increased with the number of operative rules. In fMRI data, analyses of the instruction period showed that the bilateral inferior frontal sulcus, intraparietal sulcus, and presupplementary motor area were phasically active with presentation of each new rule. In a broader range of frontal and parietal regions, baseline activity gradually increased as successive rules were instructed. During task performance, we observed contrasting fronto-parietal patterns of sustained (block-related) and transient (trial-related) activity. Block, but not trial, activity showed effects of task complexity. We suggest that, as a new task is learned, a fronto-parietal representation of relevant rules and facts is assembled for future control of behavior. Capacity limits in learning and executing new rules, and their association with fluid intelligence, may be mediated by this load-sensitive fronto-parietal network
The effect of distance on reaction time in aiming movements
Target distance affects movement duration in aiming tasks but its effect on reaction time (RT) is poorly documented. RT is a function of both preparation and initiation. Experiment 1 pre-cued movement (allowing advanced preparation) and found no influence of distance on RT. Thus, target distance does not affect initiation time. Experiment 2 removed pre-cue information and found that preparing a movement of increased distance lengthens RT. Experiment 3 explored movements to targets of cued size at non-cued distances and found size altered peak speed and movement duration but RT was influenced by distance alone. Thus, amplitude influences preparation time (for reasons other than altered duration) but not initiation time. We hypothesise that the RT distance effect might be due to the increased number of possible trajectories associated with further targets: a hypothesis that can be tested in future experiments
The Ursinus Weekly, March 20, 1961
Peiffer is prom queen; Cub & Key taps 5 men • Men urged to take April SSCQ tests • A pair of lunatics, Curtain Club offering • YWCA worker to speak Monday in Paisley Hall • French Club attends Comedie Francaise • Brownback-Anders hears Ben Hauser, Jeff med student • Bogel wins two posts at meeting • Carolyn Boyer elected into Stars and Players • Ed Myers wins SPSEA regional presidential post • Festival concessions encouraged by WSGA • Students sought for jobs in amusement parks • John Swinton is named as new Weekly editor • Holl to address Young Republicans • Campus Chest figures released • Four seniors placed as high school teachers • Officer nominations invited by YM-YWCA • Father Conran to address Newman Club tonight at 6:30 • Editorial: Thank you • Letters to the editor • Eccentric circles • What does organized labor want? • Chapel commentary • Archaeology and the Bible • Intramural corner • Cindermen boast greater depth • Mermaids lose to Swarthmore, 45-30 • Girl basketballers chalk up 2 more • Norm Bramall to present tennis clinic on Thurs. • Greek gleaningshttps://digitalcommons.ursinus.edu/weekly/1337/thumbnail.jp
The no-spin zone: rotation vs dispersion support in observed and simulated dwarf galaxies
We perform a systematic Bayesian analysis of rotation vs. dispersion support (v_(rot)/σ) in 40 dwarf galaxies throughout the Local Volume (LV) over a stellar mass range 10^(3.5) M_⊙ < M⋆ < 10^8 M_⊙. We find that the stars in ∼90% of the LV dwarf galaxies studied -- both satellites and isolated systems -- are dispersion-supported. In particular, we show that 7/10 *isolated* dwarfs in our sample have stellar populations with v_(rot)/σ<0.6. All have v_(rot)/σ≲2. These results challenge the traditional view that the stars in gas-rich dwarf irregulars (dIrrs) are distributed in cold, rotationally-supported stellar disks, while gas-poor dwarf spheroidals (dSphs) are kinematically distinct in having dispersion-supported stars. We see no clear trend between v_(rot)/σ and distance to the closest L⋆ galaxy, nor between v_(rot)/σ and M⋆ within our mass range. We apply the same Bayesian analysis to four FIRE hydrodynamic zoom-in simulations of isolated dwarf galaxies (10^9M⊙<M_(vir)<10^(10)M⊙) and show that the simulated *isolated* dIrr galaxies have stellar ellipticities and stellar v_(rot)/σ ratios that are consistent with the observed population of dIrrs *and* dSphs without the need to subject these dwarfs to any external perturbations or tidal forces. We posit that most dwarf galaxies form as puffy, dispersion-supported systems, rather than cold, angular momentum-supported disks. If this is the case, then transforming a dIrr into a dSph may require little more than removing its gas
Religious diversity, empathy, and God images : perspectives from the psychology of religion shaping a study among adolescents in the UK
Major religious traditions agree in advocating and promoting love of neighbour as well as love of God. Love of neighbour is reflected in altruistic behaviour and empathy stands as a key motivational factor underpinning altruism. This study employs the empathy scale from the Junior Eysenck Impulsiveness Questionnaire to assess the association between empathy and God images among a sample of 5993 religiously diverse adolescents (13–15 years old) attending state maintained schools in England, Northern Ireland, Scotland, Wales, and London. The key psychological theory being tested by these data concerns the linkage between God images and individual differences in empathy. The data demonstrate that religious identity (e.g. Christian, Muslim) and religious attendance are less important than the God images which young people hold. The image of God as a God of mercy is associated with higher empathy scores, while the image of God as a God of justice is associated with lower empathy scores
Macroscopic fluctuation theory
Stationary non-equilibrium states describe steady flows through macroscopic
systems. Although they represent the simplest generalization of equilibrium
states, they exhibit a variety of new phenomena. Within a statistical mechanics
approach, these states have been the subject of several theoretical
investigations, both analytic and numerical. The macroscopic fluctuation
theory, based on a formula for the probability of joint space-time fluctuations
of thermodynamic variables and currents, provides a unified macroscopic
treatment of such states for driven diffusive systems. We give a detailed
review of this theory including its main predictions and most relevant
applications.Comment: Review article. Revised extended versio
Mapping between dissipative and Hamiltonian systems
Theoretical studies of nonequilibrium systems are complicated by the lack of
a general framework. In this work we first show that a transformation
introduced by Ao recently (J. Phys. A {\bf 37}, L25 (2004)) is related to
previous works of Graham (Z. Physik B {\bf 26}, 397 (1977)) and Eyink {\it et
al.} (J. Stat. Phys. {\bf 83}, 385 (1996)), which can also be viewed as the
generalized application of the Helmholtz theorem in vector calculus. We then
show that systems described by ordinary stochastic differential equations with
white noise can be mapped to thermostated Hamiltonian systems. A steady-state
of a dissipative system corresponds to the equilibrium state of the
corresponding Hamiltonian system. These results provides a solid theoretical
ground for corresponding studies on nonequilibrium dynamics, especially on
nonequilibrium steady state. The mapping permits the application of established
techniques and results for Hamiltonian systems to dissipative non-Hamiltonian
systems, those for thermodynamic equilibrium states to nonequilibrium steady
states. We discuss several implications of the present work.Comment: 18 pages, no figure. final version for publication on J. Phys. A:
Math & Theo
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