1,911 research outputs found

    Physiological and Metabolic Strain Differences in Response to Constant Light in Male Mice

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    Circadian rhythms, located in all organisms, is an innate natural clock system driving daily cycles in behavior and metabolism. This clock entrains to daily cycles via regular exposure to light:dark cycles. When light exposure is altered, it is known to cause alterations behavior and metabolism because of its role in regulating bodily function. Constant light (LL) is emerging as a predominant circadian disruption due to prolonged exposure to light at night during night-shift work, and the use of TVs and smartphones at night and throughout the night. To understand how different organisms respond to constant light, two comparative studies were performed. In each, two genetically similar strains of mice were used to identify strain differences regarding physiologic and metabolic responses to constant light. The first using two strains of C57BL/6 (C57BL6/J and C57BL6/N) mice to establish differences in response to running wheel (RW) access in LL and the second consisted of two CBA (CBA/J and CBA/CaJ) mouse strains to define differences associated with retinal function in LL. Physiologic and metabolic data were collected through behavioral assays including the open field test, the light-dark box (LD Box), and the novel object test. Metabolic assays including the glucose tolerance test (GTT), and thyroid stimulating hormone (TSH), free thyroxine (fT4), brain-derived neurotrophic factor (BDNF), insulin, liver triglyceride, and testosterone enzyme-linked immunosorbent assays (ELISAs) were used. Several baseline differences in the C57BL/6 strains were established including C57BL6/J mice (B6J) experiencing increased locomotor activity compared to C57BL6/N (B6N) mice. In LL, B6J mice also exhibited greater period lengthening and increased anxiety compared to B6N mice. These results demonstrate strain specific differences in behavioral and physiological responses to LL and RW access. Additionally, baseline differences were observed circadian locomotor activity, behavior, and metabolism in the CBA strains. CBA/CaJ (sighted) mice experienced the effects of LL (period lengthening and weight gain) most severely as the CBA/J (blind) mice responded the same regardless of the photoperiod exposed to. These results suggest a clear photoperiod and retinal function connection

    Quasi-periodic attractors, Borel summability and the Bryuno condition for strongly dissipative systems

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    We consider a class of ordinary differential equations describing one-dimensional analytic systems with a quasi-periodic forcing term and in the presence of damping. In the limit of large damping, under some generic non-degeneracy condition on the force, there are quasi-periodic solutions which have the same frequency vector as the forcing term. We prove that such solutions are Borel summable at the origin when the frequency vector is either any one-dimensional number or a two-dimensional vector such that the ratio of its components is an irrational number of constant type. In the first case the proof given simplifies that provided in a previous work of ours. We also show that in any dimension dd, for the existence of a quasi-periodic solution with the same frequency vector as the forcing term, the standard Diophantine condition can be weakened into the Bryuno condition. In all cases, under a suitable positivity condition, the quasi-periodic solution is proved to describe a local attractor.Comment: 10 page

    Acceptance and commitment therapy delivered in a dyad after a severe traumatic brain injury: a feasibility study

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    Objective: There is a high prevalence of complex psychological distress after a traumatic brain injury but limited evidence of effective interventions. We examined the feasibility of Acceptance and Commitment Therapy after a severe traumatic brain injury using the criteria, investigating a therapeutic effect, and reviewing the acceptability of measures, treatment protocol, and delivery method (in a dyad of two clients and a therapist). Method: Two male outpatients with severe traumatic brain injury and associated psychological distress jointly engaged in a seven session treatment program based on Acceptance and Commitment Therapy principles. Pre- and post-treatment measures of mood, psychological flexibility, and participation were taken in addition to weekly measures. Results: The intervention showed a therapeutic effect with one participant, and appeared to be acceptable for both participants with regard to program content, measures, and delivery mode by in a dyad. One participant showed both significant clinical and reliable change across several outcome measures including measures of mood and psychological flexibility. The second participant did not show a reduction in psychological inflexibility, but did show a significant drop in negative affect. Significant changes pre- to post-treatment for measures of participation were not indicated. Qualitatively, both participants engaged in committed action set in accordance with their values. Conclusions: This study suggests that Acceptance and Commitment Therapy may be feasible to be delivered in a dyad with individuals who have a severe traumatic brain injury. A further test of its potential efficacy in a phase II clinical trial is recommended

    Thermal plume entrainment of ichthyoplankton at the VEPCO Surry Nuclear Power Station : progress report, October 1975

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    Plume entrainment studies at Vepco Nuclear Power Plant located near Surry, Virginia were initiated in August, 1975 by the Ichthyology department of Virginia Institute of Marine Science. The program was undertaken to define the amount and kinds of fish eggs and larvae that are. present in the Cobham Bay area of the James River and become entrained by the heated effluent

    How much wind energy will be curtailed on the 2020 Irish power system?

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    This paper describes a model of the 2020 Irish electricity system which was developed and solved in a mixed integer programming, unit commitment and economic dispatch tool called PLEXOS. The model includes all generators on the island of Ireland, a simplified representation of the neighbouring British system including proposed wind capacity and interconnectors between the two systems. The level of wind curtailment is determined under varying levels of three influencing factors. The first factor is the amount of offshore wind, the second is the allowed limit of system non-synchronous penetration (SNSP) and the third is inclusion or exclusion of transmission constraints. A binding constraint, resulting from the 2020 EU renewable energy targets, is that 37% of generation comes from wind. When the SNSP limit was increased from 60% to 75% there was a reduction in wind curtailment from 14% to 7%, with a further reduction when the proportion of wind capacity installed offshore was increased. Wind curtailment in the range of SNSP limit of 70-100% is influenced primarily by the inclusion of transmission constraints. Large changes in the dispatch of conventional generators were also evident due to the imposition of SNSP limits and transmission constraints
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