1,553,785 research outputs found
Blockchain Mining Games with Pay Forward
We study the strategic implications that arise from adding one extra option
to the miners participating in the bitcoin protocol. We propose that when
adding a block, miners also have the ability to pay forward an amount to be
collected by the first miner who successfully extends their branch, giving them
the power to influence the incentives for mining. We formulate a stochastic
game for the study of such incentives and show that with this added option,
smaller miners can guarantee that the best response of even substantially more
powerful miners is to follow the expected behavior intended by the protocol
designer
Role of antioxidant supplementation and exercise regimen in handling oxidative stress from natural PM2.5 exposure due to boreal forest fire
Thesis (M.S.) University of Alaska Fairbanks, 2019Particulate matter 2.5 (PM2.5) exposure induces oxidative stress that causes many negative health outcomes such as cancer, cardiovascular disease and neurodegenerative disease. Research shows that dietary antioxidants and an up-regulated endogenous antioxidant response from exercise play key roles in the antioxidant defense against oxidative stress. This study is the first to use an animal model to investigate the cumulative effects of using lifestyle interventions of antioxidant supplementation (Arthrospira platensis) and exercise regimen on the antioxidant response before, during, and after ambient PM2.5 exposure. In a two-factorial, longitudinal design, sled dogs (n=48) were divided into four groups (exercise and supplemented, exercise, supplemented, and control) to (1) test the effects of exercise and antioxidant regimen on antioxidant response after one month of implemented exercise and supplementation protocol and (2) measure the antioxidant response of all groups during and after a natural forest fire event in 2015. Commercial assays for Total antioxidant Power (TAP) and the enzymatic antioxidant Superoxide Dismutase (SOD) were used as markers for the total antioxidant response and the endogenous response at all time points. During the forest fire, SOD was increased 5-10-fold over pre/post-exposure levels in all groups suggesting potential implication for using SOD as a marker for the acute response to environmental stress. TAP was increased in the exercise groups after one month of exercise protocol implementation, demonstrating the cytoprotective increase of antioxidants after repeated exercise.Chapter 1: Introduction -- 1.1 PM2.5 -- 1.2 Oxidative stress and exercise -- 1.3 Antioxidants -- 1.4 Significance and research hypothesis -- Chapter 2 The effects of spirulina supplementation and exercise regimen on the antioxidant response to PM2.5 exposure in sled dogs -- 2.1 Introduction -- 2.2 Materials and methods -- 2.2.1 Animals -- 2.2.2 Experimental design -- 2.2.4 Exercise -- 2.2.5 Blood sampling -- 2.2.6 Biochemical analyses -- 2.2.7 Statistics -- 2.3 Results -- 2.4 Discussion -- 2.5 Conclusions -- Chapter 3 Conclusions and future directions -- References
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
Saliency of Outside Options in the Lost Wallet Game
This paper reports an experiment designed to shed light on an empirical puzzle observed by Dufwenberg and Gneezy (2000) that the size of the foregone outside option by the first mover does not affect the behavior of the second mover in a lost wallet game. Our conjecture was that the original protocol may not have made the size of the forgone outside option salient to second movers. Therefore, we change two features of the Dufwenberg and Gneezy protocol: (i) instead of the strategy method we implement a direct response method (sequential play) for the decision of the second mover; and (ii) we use paper money certificates that are passed between the subjects rather than having subjects write down numbers representing their decisions. We observe that our procedure yields qualitatively the same result as the Dufwenberg and Gneezy experiment, i.e., the second movers do not respond to the change in the outside option of the first movers.Experimental economics; Lost wallet game; Outside option
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Human Trafficking in the Emergency Department: Improving Our Response to a Vulnerable Population
Human trafficking is a human rights violation affecting millions worldwide. Victims may go unrecognized during their emergency department (ED) visit, and may lose the opportunity to address their complex needs. Using a published toolkit based on existing guidelines and recommendations from experts, and models from other centers, we describe the implementation of an ED response protocol. In following the recommendations of the toolkit, we began with attempts to fully understand the local human trafficking problem and then networked with those working in anti-trafficking efforts. Collaboration with other specialties is highlighted as a key part of this process. Building upon the knowledge gained from these steps, we were able to develop a concise protocol to guide members of our department in more effectively caring for known or suspected victims of human trafficking. The first section of the protocol addresses ways in which providers can identify at-risk patients through both screening questions and general observations. Interviewing techniques are outlined with an emphasis on patient-centered and trauma-informed care. Additionally, the protocol discusses physician responsibility in documenting encounters and legal reporting, which may vary depending on location. We stress the importance of meeting the needs of the patient while prioritizing the safety of all involved. Additionally, the protocol provides a list of resources for the patient beyond medical care such as emergency housing, legal assistance, and food pantries. The overall purpose of this protocol is to provide coordinated response so that all providers may be consistent in caring for this vulnerable population
On the protocol dependence of plasticity in ultra-stable amorphous solids
While perfect crystals may exhibit a purely elastic response to shear all the
way to yielding, the response of amorphous solids is punctuated by plastic
events. The prevalence of this plasticity depends on the number of particles
of the system, with the average strain interval before the first plastic
event, , scaling like with
negative: larger samples are more susceptible to plasticity due to more
numerous disorder-induced soft spots. In this paper we examine this scaling
relation in ultra-stable glasses prepared with the Swap Monte Carlo algorithm,
with regard to the possibility of protocol-dependent scaling exponent, which
would also imply a protocol dependence in the distribution of local yield
stresses in the glass. We show that, while a superficial analysis seems to
corroborate this hypothesis, this is only a pre-asymptotic effect and in fact
our data can be well explained by a simple model wherein such protocol
dependence is absent.Comment: 7 pages, 9 figures; figures improved, implications on the issue of a
static glass lengthscale are discusse
Pilot Testing Behavior Therapy for Chronic Tic Disorders in Neurology and Developmental Pediatrics Clinics
Comprehensive Behavioral Intervention for Tics (CBIT) is an efficacious treatment with limited regional availability. As neurology and pediatric clinics are often the first point of therapeutic contact for individuals with tics, the present study assessed preliminary treatment response, acceptability, and feasibility of an abbreviated version, modified for child neurology and developmental pediatrics clinics. Fourteen youth (9-17) with Tourette disorder across 2 child neurology clinics and one developmental pediatrics clinic participated in a small case series. Clinician-rated tic severity (Yale Global Tic Severity Scale) decreased from pre- to posttreatment, z = –2.0, P \u3c .05, r = –.48, as did tic-related impairment, z = –2.4, P \u3c .05, r = –.57. Five of the 9 completers (56%) were classified as treatment responders. Satisfaction ratings were high, and therapeutic alliance ratings were moderately high. Results provide guidance for refinement of this modified CBIT protocol
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