96 resultados para intermittent


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Purpose
To examine the effects of four commonly used recovery treatments applied between two bouts of intense endurance cycling on the performance of the second bout in normothermia (~21 °C).

Methods
Nine trained men completed two submaximal exhaustive cycling bouts (Ex1 and Ex2: 5 min at ~50 % V˙O2 peak, followed by 5 min at ~60 % V˙O2 peak and then ~80 % V˙O2 peak to failure) separated by 30 min of (a) cold water immersion at 15 °C (C15), (b) contrast water therapy alternating 2.5 min at 8 °C and 2.5 min at 40 °C (CT), (c) thermoneutral water immersion at 34 °C (T34) and (d) cycling at ~40 % V˙O2 peak (AR).

Results
Exercise performance, cardiovascular and metabolic responses during Ex1 were similar among all trials. However, time to failure (~80 % V˙O2 peak bout) during Ex2 was significantly (P < 0.05) longer in C15 (18.0 ± 1.6) than in CT (14.5 ± 1.5), T34 (12.4 ± 1.4) and AR (10.6 ± 1.0); and it was also longer (P < 0.05) in CT than AR. Core temperature and heart rate were significantly (P < 0.05) lower during the initial ~15 min of Ex2 during C15 compared with all other conditions but they reached similar levels at the end of Ex2.

Conclusions
A 30 min period of C15 was more beneficial in maintaining intense submaximal cycling performance than CT, T34 and AR; and CT was also more beneficial than T34 and AR. These effects were not mediated by the effect of water immersion per se, but by the continuous (C15) or intermittent (CT) temperature stimulus (cold) applied throughout the recovery.

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Wind energy is one of the most promising renewable energy sources due to its availability and climate-friendly attributes. Large-scale integration of wind energy sources creates potential technical challenges due to the intermittent nature that needs to be investigated and mitigated as part of developing a sustainable power system for the future. Therefore, this study developed simulation models to investigate the potential challenges, in particular voltage fluctuations, zone substation, and distribution transformer loading, power flow characteristics, and harmonic emissions with the integration of wind energy into both the high voltage (HV) and low voltage (LV) distribution network (DN). From model analysis, it has been clearly indicated that influences of these problems increase with the increased integration of wind energy into both the high voltage and low voltage distribution network, however, the level of adverse impacts is higher in the LV DN compared to the HV DN.

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This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of ustekinumab for the treatment of moderate to severe psoriasis based upon a review of the manufacturer's submission to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The submission's main evidence came from three randomised controlled trials (RCTs), of reasonable methodological quality and measuring a range of clinically relevant outcomes. Higher proportions of participants treated with ustekinumab (45 mg and 90 mg) than with placebo or etanercept achieved an improvement on the Psoriasis Area and Severity Index (PASI) of at least 75% (PASI 75) after 12 weeks. There were also statistically significant differences in favour of ustekinumab over placebo for PASI 50 and PASI 90 results, and for ustekinumab over etanercept for PASI 90 results. A weight-based subgroup dosing analysis for each trial was presented, but the methodology was poorly described and no statistical analysis to support the chosen weight threshold was presented. The manufacturer carried out a mixed treatment comparison (MTC); however, the appropriateness of some of the methodological aspects of the MTC is uncertain. The incidence of adverse events was similar between groups at 12 weeks and withdrawals due to adverse events were low and less frequent in the ustekinumab than in the placebo or etanercept groups; however, statistical comparisons were not reported. The manufacturer's economic model of treatments for psoriasis compared ustekinumab with other biological therapies. The model used a reasonable approach; however, it is not clear whether the clinical effectiveness estimates from the subgroup analysis, used in the base-case analysis, were methodologically appropriate. The base-case incremental cost-effectiveness ratio for ustekinumab versus supportive care was 29,587 pounds per quality-adjusted life-year (QALY). In one-way sensitivity analysis the model was most sensitive to the number of hospital days associated with supportive care, the cost estimate for intermittent etanercept 25 mg and the utility scores used. In the ERG's scenario analysis the model was most sensitive to the price of ustekinumab 90 mg, the proportion of patients with baseline weight > 100 kg and the relative risk of intermittent versus continuous etanercept 25 mg. In the ERG's probabilistic sensitivity analysis ustekinumab had the highest probability of being cost-effective at conventional NICE thresholds, assuming the same price for the 45-mg and 90-mg doses; however, doubling the price of ustekinumab 90 mg resulted in ustekinumab no longer dominating the comparators. In conclusion, the clinical effectiveness and cost-effectiveness of ustekinumab in relation to other drugs in this class is uncertain. Provisional NICE guidance issued as a result of the STA states that ustekinumab is recommended as a treatment option for adults with plaque psoriasis when a number of criteria are met. Final guidance is anticipated in September 2009.

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 This article presents SOR, a vehicular social network to enable social communications and interactions among users on the road during their highway travels. Motivated by the limited connection to Internet contents and services, the essential goal of SOR is to encourage distributed users on the road to spontaneously contribute as the information producer, assembler, and distributer in order to provide timely and localized infotainments to each other through low-cost inter-vehicle communications. To be specific, SOR enables individual users to maintain a personal blog, similar to one on Facebook and Twitter, over which users can create and share personal content information to the public such as travel blogs with pictures and videos. By accessing each other's SOR blogs and commenting on interesting topics, passengers can exchange messages and initiate social interactions. In the specific highway environment, SOR addresses two challenges in the context of vehicular social communications. First, vehicular social communications tend to be frequently interrupted by diverse vehicle mobility and intermittent intervehicle connections, which is annoying to users. To address this issue, SOR adopts a proactive mechanism by estimating the connection time between peer vehicles, and recommending vehicles with relatively long-lasting and stable intervehicle connections for social communications. Second, as users on the road are typically strangers to each other, they are reluctant to disclose personal information to others. This makes it challenging to identify users of shared interests and accordingly restricts the scale of users' social interactions. To remedy that, SOR provides a secured solution to protect sensitive user information during social communications. Lastly, we use simulations to verify the performance of SOR. © 2015 IEEE.

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Studies conducted in community samples suggest that psychotic-like experiences are common in the general population, leading to suggestions that they are either variations of normal personality or are different expressions of underlying vulnerability to psychotic disorder. Different types of psychotic symptoms may exist, some being normal variants and some having implications for mental health and functioning. The aim of the present study was to determine if different subtypes of psychotic-like experiences could be identified in a community sample of adolescents and to investigate if particular subtypes were more likely to be associated with psychosocial difficulties, that is, distress, depression and poor functioning, than other subtypes. Eight hundred and seventy-five Year 10 students from 34 schools participated in a cross-sectional survey that measured psychotic-like experiences using the Community Assessment of Psychic Experiences; depression using the Centre for Epidemiologic Studies Depression Scale; and psychosocial functioning using the Revised Multidimensional Assessment of Functioning Scale. Factor analysis was conducted to identify any subtypes of psychotic experiences. Four subtypes of psychotic-like experiences were identified: Bizarre Experiences, Perceptual Abnormalities, Persecutory Ideas, and Magical Thinking. Intermittent, infrequent psychotic experiences were common, but frequent experiences were not. Bizarre Experiences, Perceptual Abnormalities and Persecutory Ideas were strongly associated with distress, depression and poor functioning. Magical Thinking was only weakly associated with these variables. Overall these findings may suggest that infrequent psychotic-like experiences are unlikely to be a specific risk factor for onset of a psychotic disorder in community samples. Given that the different subtypes had varying associations with current difficulties it is suggested that not all subtypes confer the same risk for onset of psychotic disorder and poor outcome. Bizarre Experiences, Perceptual Abnormalities and Persecutory Ideas may represent expressions of underlying vulnerability to psychotic disorder, but Magical Thinking may be a normal personality variant.

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Travellers in vehicles often have strong willingness to share their travel experience and exchange information to each other through social networks2, such as Facebook and Twitter. This, however, can be costly due to the limited connections to Internet on the road. In this paper we develop Verse to facilitate the social communications among vehicle travellers on highways. Verse enables passengers on-board vehicles to share the content information, such as travel blogs with pictures, among each other using the impromptu wireless inter-vehicle communications. Unlike traditional online social networks, which are built upon the reliable IP networks, vehicular social networks face fundamental challenges in that: 1) users are anonymous and strangers to each other and hard to identify potential friends of shared interests, and 2) users communicate through intermittent and unreliable inter-vehicle connections. On addressing the two challenges, Verse implements a friend recommendation function, which helps passengers efficiently identify potential social friends with both shared interests and relatively reliable wireless connections. In addition, Verse is equipped with a social-aware rate control scheme towards efficient utilization of network bandwidth. Using extensive simulations, we show that the friend recommendation function of Verse can effectively predict the mobility of vehicles to assist the social communication, and the social-aware rate control scheme quickly and efficiently adapts the vehicle’s transmission rate according to their social impacts.

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The recent advances in wireless communication techniques have made it possible for fast-moving vehicles to download data from the roadside communications infrastructure [e.g., IEEE 802.11b Access Point (AP)], namely, Drive-thru Internet. However, due to the high mobility, harsh, and intermittent wireless channels, the data download volume of individual vehicle per drive-thru is quite limited, as observed in real-world tests. This would severely restrict the service quality of upper layer applications, such as file download and video streaming. On addressing this issue, in this paper, we propose ChainCluster, a cooperative Drive-thru Internet scheme. ChainCluster selects appropriate vehicles to form a linear cluster on the highway. The cluster members then cooperatively download the same content file, with each member retrieving one portion of the file, from the roadside infrastructure. With cluster members consecutively driving through the roadside infrastructure, the download of a single vehicle is virtually extended to that of a tandem of vehicles, which accordingly enhances the probability of successful file download significantly. With a delicate linear cluster formation scheme proposed and applied, in this paper, we first develop an analytical framework to evaluate the data volume that can be downloaded using cooperative drive-thru. Using simulations, we then verify the performance of ChainCluster and show that our analysis can match the simulations well. Finally, we show that ChainCluster can outperform the typical studied clustering schemes and provide general guidance for cooperative content distribution in highway vehicular communications.

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To compare the effect of 7 h of prolonged sitting on resting blood pressure with a similar duration of sitting combined with intermittent brief bouts of light-intensity or moderate-intensity physical activity.

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In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010) to assess the longer-term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1) remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus) and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006-2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human-made dispersal barriers downstream need to be identified and ameliorated, to allow native fish to fulfil their life cycles in these headwater streams.

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The abundance, availability, and climate-friendly characteristics of solar photovoltaic (PV) energy encourage nations around the globe to adopt it to assist in overcoming global warming as well as build a sustainable society for the future. The intermittent nature of solar energy generation and the associated power electronic inverters with connected consumer loads creates a number of potential challenges in integrating large-scale PV into the grid that affects power quality of the distribution networks. This paper investigates the impacts of varying PV integration into the grid through experimental and simulation studies. Initially, several experiments were conducted with varying PV penetration and load conditions using the Renewable Energy Integration Facility at CSIRO, Newcastle, Australia. Later, a simulation model was developed that mimics the experimental facility used at CSIRO to investigate the adverse impacts on integrating large-scale PV into the grid using the power system simulation software PSS Sincal. Experimental and simulation analyses clearly indicate that integration of PV into the grid causes power quality issues such as voltage instability, harmonic injection, and low power factor into the networks and the level of these impacts increases with the increase of PV penetration. © 2014 AIP Publishing LLC.

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The advancement in solar photovoltaic (PV) technology, the cost and efficiency of PVs have encouraged users worldwide to adopt more and more PVs as it is free from greenhouse gas emissions and unlimited in nature. Integration of roof-top solar PV systems is currently emerging rapidly in Australia as the governments are giving attractive incentives and encouraging households to build a sustainable climate-friendly society for the future. The key major barriers to the integration of roof-top solar PV systems are the uncertainties in the performance of the low voltage distribution network due to the intermittent nature of solar PV sources. In this paper, a model was developed to investigate the potential technical impacts of integrating roof-top solar PV systems into the low voltage distribution network in a subtropical climate. The results show that integration of roof-top solar PV in the customer premises causes uncertainties such as voltage fluctuations, phase unbalance, distribution transformer overloading, reactive power compensation, and harmonic injections that detract the overall power quality of the typical distribution network. © 2014 AIP Publishing LLC.

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Increased concern about global warming coupled with the escalating demand of energy has driven the conventional power system to be more reliable one by integrating Renewable Energies (RE) in to grid. Over the recent years, integration of solar PV forming a gridconnected PV is considered as one of the most promisingtechnologies to the developed countries like Australia to meet the growing demand of energy. This rapid increase in grid connected photovoltaic (PV) systems has made the supply utilities concerned about the drastic effects that have to be considered on the distribution network in particular voltage fluctuations, harmonic distortions and the Power factor for sustainable power generation. However, irrespective of thefact that the utility grid can accommodate the variability of load or irregular solar irradiance, it is essential to study the impact of grid connected PV systems during higher penetration levels as the intermittent nature of solar PV adversely effects the grid characteristics in meeting the load demand. Hence, keeping this in track, this paper examines the grid-connected PV system considering a residential network of Geelong region (38◦.09' S and 144◦.21’ E) and explores the level of impacts considering summer load profile with a change in the level of integrations. Initially, a PV power system network model is developed in Matlab-Simulink environment and the simulations are carried out to explore the impacts of solar PV penetration at low voltage distribution network considering power quality (PQ) issues such as voltage fluctuations, harmonics distortion at different load conditions.

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Lectrides varians (Mosely) is a large, ecologically-important, caddisfly found in perennial and intermittent streams throughout much of eastern Australia. We conducted a population genetic analysis to investigate the dispersal potential of L. varians, building on previous works that have assessed life-history traits associated with drought resistance. Genetic analyses of L. varians from the Grampians region of Victoria, based on mitochondrial DNA sequence data, revealed extensive gene flow and a lack of genetic structure across the sample range (ΦST = 0.04). This suggests that the species is a strong disperser and is likely to be resilient to increased drying and habitat fragmentation under climate change considering other known resistance traits. However, during this study, two divergent genotypes were identified, indicating a potential species complex. A comprehensive phylogenetic analysis of L. varians across its current range was subsequently performed, confirming the species is indeed paraphyletic, consisting of one lineage that is restricted to the Grampians National Park and the other being widespread throughout south-eastern Australia. Further analyses revealed consistent morphological differences between these lineages supporting the notion that L. varians is a species complex. We discuss the implications of these findings with regard to conservation and taxonomy of this important invertebrate group.

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This chapter seeks to extend earlier works on Mesopotamian democracy to a civilisation that is not only typically excluded from such discussions of democracy in the ancient Near East, but generally considered to be among the region’s most bloodthirsty and bellicose: the Assyrians. On the one hand it cannot be denied that the Assyrians went through periods of aggressive expansion, that they were cruel to at least some of their enemies and that the more militant Assyrian kings struck fear into the hearts of men and women across the region (I:106-110, 113; II:1, 54-6 in: Grayson 1991: 201). On the other hand, however, it is peculiar that the intermittent war-mongering of the Assyrians is seen not only as ‘a modern myth exaggerated beyond all proportion’ (Parpola 2003: 1060), but also seen to exclude them from practicing any form of democracy. This is starkly inconsistent with the contemporary assessment of other societies of the ancient world, such as the Greeks or Romans who were both belligerent and at least nominally democratic. To give one example of this double standard, Jana Pecirkova argues that while the Greek polis enabled the birth of science, philosophy and the rule of law, the Assyrians were not able to distinguish ‘between the rational and the irrational, between reality and illusion’ (Pecirkova 1985: 155). The reason for this, according to Pecrikova, is simple: their ‘only alternative to monarchy … was anarchy … Political decisions were arbitrary in character and not governed by any laws or generally acknowledged and accepted rules’ and the ‘people were the passive subjects of political decision-making’ (Pecirkova 1985: 166-8). This chapter, while cautious not to over-state the democratic tendencies of the Assyrians, takes Pecirkova’s argument to task by examining the complex functioning of power and politics, the checks and balances on monarchical authority, the rule of law and the sophisticated intellectual scene of the three key epochs of ancient Assyrian civilisation.

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Cloud services to smart things face latency and intermittent connectivity issues. Fog devices are positioned between cloud and smart devices. Their high speed Internet connection to the cloud, and physical proximity to users, enable real time applications and location based services, and mobility support. Cisco promoted fog computing concept in the areas of smart grid, connected vehicles and wireless sensor and actuator networks. This survey article expands this concept to the decentralized smart building control, recognizes cloudlets as special case of fog computing, and relates it to the software defined networks (SDN) scenarios. Our literature review identifies a handful number of articles. Cooperative data scheduling and adaptive traffic light problems in SDN based vehicular networks, and demand response management in macro station and micro-grid based smart grids are discussed. Security, privacy and trust issues, control information overhead and network control policies do not seem to be studied so far within the fog computing concept.