2,076 research outputs found
INTRODUCTION OF A NOVEL HOME-BASED HIGH-INTENSITY INTERVAL TRAINING PROGRAMME TO IMPROVE CARDIO-METABOLIC HEALTH IN AT-RISK INDIVIDUALS
New strategies are urgently needed to increase physical activity participation in the increasingly sedentary population to combat the rising rates of obesity and metabolic disease. The aim of this thesis was to provide evidence that practical high-intensity interval training (HIT) strategies can remove many of the major exercise barriers for obese individuals and people with type 1 diabetes that could potentially increase physical activity participation. Secondly, this thesis aimed to provide mechanistic evidence to explain the physiological effectiveness of HIT as a means to reduce the risk of cardio-metabolic disease. In Chapters 4 and 5, 32 obese adults with at least 3 additional cardiovascular disease (CVD) risk factors completed one of three 12-week training programmes 3x/week: Home-HIT (n=9); Laboratory-based supervised HIT (Lab-HIT; n=10) or home-based moderate intensity continuous training (Home-MICT; n=13). Changes in V ÌO2peak, insulin sensitivity, body composition, flow-mediated dilation (FMD) and aortic pulse wave velocity (PWV) were assessed. Muscle biopsies were taken to assess changes in capillarisation, mitochondrial density, intramuscular triglyceride (IMTG) content and eNOS and GLUT4 protein expression using quantitative immunofluorescence microscopy. Adherence and compliance (Home-HIT 96±3% & 99±1%; Home-MICT 88±4% & 100±0%; Lab-HIT 97±1% & 100±0%, respectively) to training did not differ between groups. Training increased V ÌO2peak and Matsuda insulin sensitivity index (P<0.05). BMI, body fat percentage and visceral fat decreased (P<0.05). FMD increased and aortic PWV decreased in each group (P<0.05). Immunofluorescence microscopy revealed increased capillarisation, mitochondrial density, IMTG content and eNOS and GLUT4 protein expression (P<0.05). In Chapter 6, 14 people with type 1 diabetes completed a randomised counterbalanced crossover design whereby continuous glucose monitoring was used to assess glycaemic control and risk of hypoglycaemia following a single bout of HIT and moderate-intensity continuous training (MICT) on separate days, compared to a non-exercise control day (CON). In Chapter 7, 14 people with type 1 diabetes (n=7 per group) completed six weeks of HIT or MICT 3x/week and the effect on glucose control and markers of cardio-metabolic health were measured. Chapter 6 showed no difference in the time, incidence or severity of hypoglycaemia over the 24-hour or nocturnal period between the CON, HIT and MICT days. In Chapter 7, six weeks of HIT or MICT improved V ÌO2max by 14% and 15%, respectively and aortic PWV by 12%, with no difference between groups. Therefore, Chapters 6 and 7 demonstrate that HIT is an effective exercise strategy for people with type 1 diabetes that reduces the two major barriers of lack of time and fear of hypoglycaemia. Finally, in Chapter 8, eleven previously sedentary individuals with type 1 diabetes completed 6 weeks of Home-HIT. Blood glucose was monitored before, immediately and 1h after all of the exercise sessions. Perceptions of the program along with attitudes towards exercise, barriers to exercise and previous experiences of exercise were evaluated using an online survey. Training session adherence was 93±2%, with participants achieving their target HR in 99±1% of sessions. Blood glucose was not different from baseline immediately or 1h post HIT exercise. Training increased V ÌO2peak by 8% (P=0.015), but blood pressure was unchanged (P=0.445). The qualitative data showed that the Home-HIT programme was positively received with many benefits. In conclusion, this thesis provides strong evidence that HIT can reduce major barriers to exercise and potentially increase exercise participation in these at-risk populations. Furthermore, Home-HIT was shown to be an effective strategy to improve a wide range of physiological markers indicative of improved cardio-metabolic health. Importantly, Home-HIT not only reduced traditional barriers to exercise, but also the key barrier in people with type 1 diabetes, fear of hypoglycaemia. As such, Home-HIT may represent an effective strategy to improve health in obese individuals with elevated CVD and people with type 1 diabetes by increasing exercise participation. Future research should investigate the effects of Home-HIT on a larger scale using larger cohorts and longer training periods using large-scale randomised controlled trials
Current Trends in High-Grade Gliomas
This is an overview of the current trends in the management of high-grade gliomas based on the current evidence available at the time of compiling this chapter in the first quarter of 2016, by a dedicated, high-volume Neurosurgical Oncology team of clinical and surgical Neuro-Oncologists based in central Pennsylvania
Symmetric informationally complete positive operator valued measure and probability representation of quantum mechanics
Symmetric informationally complete positive operator valued measures
(SIC-POVMs) are studied within the framework of the probability representation
of quantum mechanics. A SIC-POVM is shown to be a special case of the
probability representation. The problem of SIC-POVM existence is formulated in
terms of symbols of operators associated with a star-product quantization
scheme. We show that SIC-POVMs (if they do exist) must obey general rules of
the star product, and, starting from this fact, we derive new relations on
SIC-projectors. The case of qubits is considered in detail, in particular, the
relation between the SIC probability representation and other probability
representations is established, the connection with mutually unbiased bases is
discussed, and comments to the Lie algebraic structure of SIC-POVMs are
presented.Comment: 22 pages, 1 figure, LaTeX, partially presented at the Workshop
"Nonlinearity and Coherence in Classical and Quantum Systems" held at the
University "Federico II" in Naples, Italy on December 4, 2009 in honor of
Prof. Margarita A. Man'ko in connection with her 70th birthday, minor
misprints are corrected in the second versio
Structural effects in UO thin films irradiated with fission-energy Xe ions
Uranium dioxide thin films have been successfully grown on LSAT (AlLaOSrTa) substrates by reactive magnetron sputtering. Irradiation by 92 MeV Xe ions to simulate fission damage that occurs within nuclear fuels caused microstructural and crystallographic changes. Initially flat and continuous thin films were produced by magnetron sputtering with a root mean square roughness of 0.35 nm determined by AFM. After irradiation, this roughness increased to 60-70 nm, with the films developing discrete microstructural features: small grains (~3 m), along with larger circular (up to 40 m) and linear formations with non-uniform composition according to the SEM, AFM and EDX results. The irradiation caused significant restructuring of the UO films that was manifested in significant filmsubstrate mixing, observed through EDX analysis. Diffusion of Al from the substrate into the film in unirradiated samples was also observed.Engineering and Physical Sciences Research Council (Grant ID: EP/ I036400/1), Radioactive Waste Management Ltd (formerly the Radioactive Waste Management Directorate of the UK Nuclear Decommissioning Authority, contract NPO004411A-EPS02), Russian Foundation for Basic Research (projects 13-03-90916), CSAR, Grand AccelĂ©lĂ©rateur National dâIons Lourds (GANIL) Caen France, French Network EMIR, CIMAP-CIRIL, M.V.Lomonosov Moscow State University Program of Development, CKP FMI IPCE RA
The Expanding Fireball of Nova Delphini 2013
A classical nova occurs when material accreting onto the surface of a white
dwarf in a close binary system ignites in a thermonuclear runaway. Complex
structures observed in the ejecta at late stages could result from interactions
with the companion during the common envelope phase. Alternatively, the
explosion could be intrinsically bipolar, resulting from a localized ignition
on the surface of the white dwarf or as a consequence of rotational distortion.
Studying the structure of novae during the earliest phases is challenging
because of the high spatial resolution needed to measure their small sizes.
Here we report near-infrared interferometric measurements of the angular size
of Nova Delphini 2013, starting from one day after the explosion and continuing
with extensive time coverage during the first 43 days. Changes in the apparent
expansion rate can be explained by an explosion model consisting of an
optically thick core surrounded by a diffuse envelope. The optical depth of the
ejected material changes as it expands. We detect an ellipticity in the light
distribution, suggesting a prolate or bipolar structure that develops as early
as the second day. Combining the angular expansion rate with radial velocity
measurements, we derive a geometric distance to the nova of 4.54 +/- 0.59 kpc
from the Sun.Comment: Published in Nature. 32 pages. Final version available at
http://www.nature.com/nature/journal/v515/n7526/full/nature13834.htm
Home-based high-intensity interval training reduces barriers to exercise in people with type 1 diabetes
People with type 1 diabetes (T1D) are recommended to engage in regular exercise for a variety of health and fitness reasons. However, many lead a sedentary lifestyle and fail to meet the physical activity guidelines, in part because of the challenge of managing blood glucose concentration and fear of hypoglycaemia. A number of strategies designed to help people with T1D to manage their blood glucose during and after exercise have been investigated. Although many of these strategies show promise in facilitating blood glucose management during and after exercise, they do not target the many other common barriers to exercise that people with T1D face, such as difficulty with cost and travel time to gyms, limited access to exercise bikes and treadmills, and a possible dislike of exercising in front of others in public places. In this symposium review, we provide an overview of ongoing research into a virtually monitored homeâbased highâintensity interval training (HomeâHIT) programme that is designed to reduce these other common barriers to exercise. The conclusion of this review is that HomeâHIT seems to offer a strategy to reduce fear of hypoglycaemia, while simultaneously removing other known barriers preventing people with T1D from taking up exercise, such as being time efficient, requiring no travel time or costs associated with gym memberships, and giving them the opportunity to exercise in their chosen environment, reducing the embarrassment experienced by some when exercising in public
Emergence of scale-free close-knit friendship structure in online social networks
Despite the structural properties of online social networks have attracted
much attention, the properties of the close-knit friendship structures remain
an important question. Here, we mainly focus on how these mesoscale structures
are affected by the local and global structural properties. Analyzing the data
of four large-scale online social networks reveals several common structural
properties. It is found that not only the local structures given by the
indegree, outdegree, and reciprocal degree distributions follow a similar
scaling behavior, the mesoscale structures represented by the distributions of
close-knit friendship structures also exhibit a similar scaling law. The degree
correlation is very weak over a wide range of the degrees. We propose a simple
directed network model that captures the observed properties. The model
incorporates two mechanisms: reciprocation and preferential attachment. Through
rate equation analysis of our model, the local-scale and mesoscale structural
properties are derived. In the local-scale, the same scaling behavior of
indegree and outdegree distributions stems from indegree and outdegree of nodes
both growing as the same function of the introduction time, and the reciprocal
degree distribution also shows the same power-law due to the linear
relationship between the reciprocal degree and in/outdegree of nodes. In the
mesoscale, the distributions of four closed triples representing close-knit
friendship structures are found to exhibit identical power-laws, a behavior
attributed to the negligible degree correlations. Intriguingly, all the
power-law exponents of the distributions in the local-scale and mesoscale
depend only on one global parameter -- the mean in/outdegree, while both the
mean in/outdegree and the reciprocity together determine the ratio of the
reciprocal degree of a node to its in/outdegree.Comment: 48 pages, 34 figure
Carbohydrate Restriction in Type 1 Diabetes: A Realistic Therapy for Improved Glycaemic Control and Athletic Performance?
Around 80% of individuals with Type 1 diabetes (T1D) in the United States do not achieve glycaemic targets and the prevalence of comorbidities suggests that novel therapeutic strategies, including lifestyle modification, are needed. Current nutrition guidelines suggest a flexible approach to carbohydrate intake matched with intensive insulin therapy. These guidelines are designed to facilitate greater freedom around nutritional choices but they may lead to higher caloric intakes and potentially unhealthy eating patterns that are contributing to the high prevalence of obesity and metabolic syndrome in people with T1D. Low carbohydrate diets (LCD; <130 g/day) may represent a means to improve glycaemic control and metabolic health in people with T1D. Regular recreational exercise or achieving a high level of athletic performance is important for many living with T1D. Research conducted on people without T1D suggests that training with reduced carbohydrate availability (often termed "train low") enhances metabolic adaptation compared to training with normal or high carbohydrate availability. However, these "train low" practices have not been tested in athletes with T1D. This review aims to investigate the known pros and cons of LCDs as a potentially effective, achievable, and safe therapy to improve glycaemic control and metabolic health in people with T1D. Secondly, we discuss the potential for low, restricted, or periodised carbohydrate diets in athletes with T1D
Spontaneous and deliberate future thinking: A dual process account
© 2019 Springer Nature.This is the final published version of an article published in Psychological Research, licensed under a Creative Commons Attri-bution 4.0 International License. Available online at: https://doi.org/10.1007/s00426-019-01262-7.In this article, we address an apparent paradox in the literature on mental time travel and mind-wandering: How is it possible that future thinking is both constructive, yet often experienced as occurring spontaneously? We identify and describe two âroutesâ whereby episodic future thoughts are brought to consciousness, with each of the âroutesâ being associated with separable cognitive processes and functions. Voluntary future thinking relies on controlled, deliberate and slow cognitive processing. The other, termed involuntary or spontaneous future thinking, relies on automatic processes that allows âfully-fledgedâ episodic future thoughts to freely come to mind, often triggered by internal or external cues. To unravel the paradox, we propose that the majority of spontaneous future thoughts are âpre-madeâ (i.e., each spontaneous future thought is a re-iteration of a previously constructed future event), and therefore based on simple, well-understood, memory processes. We also propose that the pre-made hypothesis explains why spontaneous future thoughts occur rapidly, are similar to involuntary memories, and predominantly about upcoming tasks and goals. We also raise the possibility that spontaneous future thinking is the default mode of imagining the future. This dual process approach complements and extends standard theoretical approaches that emphasise constructive simulation, and outlines novel opportunities for researchers examining voluntary and spontaneous forms of future thinking.Peer reviewe
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