306 research outputs found

    Two-dimensional imaging of edge-localized modes in KSTAR plasmas unperturbed and perturbed by n=1 external magnetic fields

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    The temporal evolution of edge-localized modes (ELMs) has been studied using a 2-D electron cyclotron emission imaging system in the KSTAR tokamak. The ELMs are observed to evolve in three distinctive stages: the initial linear growth of multiple filamentary structures having a net poloidal rotation, the interim state of regularly spaced saturated filaments, and the final crash through a short transient phase characterized by abrupt changes in the relative amplitudes and distance among filaments. The crash phase, typically consisted of multiple bursts of a single filament, involves a complex dynamics, poloidal elongation of the bursting filament, development of a fingerlike bulge, and fast localized burst through the finger. Substantial alterations of the ELM dynamics, such as mode number, poloidal rotation, and crash time scale, have been observed under external magnetic perturbations with the toroidal mode number n = 1. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694842]X1125sciescopu

    The effect of pressure on DNA deposition by touch

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    Casework exhibits are routinely examined for DNA that might have been deposited by touch, although the success of downstream profiling can vary. Many variables affect DNA deposition by touch, such as ‘shedder status’, surface type, and nature of contact. This may include pressure, which has been shown to increase the transfer of DNA between two surfaces, although whether pressure can impact DNA deposition directly from skin has yet to be examined. Therefore, this study uses a novel method to investigate whether pressure can affect the amount and quality of DNA directly deposited by touch. With the fingertips of one hand, volunteers exerted pressure for one minute onto a DNA-free polycarbonate board placed on top of a balance; all five fingermarks were then swabbed and combined as one sample for DNA extraction, quantification and profiling. For each hand, the area of the combined fingertips was used to determine the weight value to which to push the balance to give pressures of 4, 21 or 37 kPa. Volunteers used both their right and left hands at each pressure in a randomised order on each day of three non-consecutive days. Increasing the pressure between skin and surface significantly increased the amount of DNA deposited, which resulted in the detection of more alleles, from both the donor and unknown sources. No significant differences were observed in the amounts of DNA deposited between hands and among different days for each volunteer. DNA amounts significantly varied between individuals at 21 and 37 kPa, but not at 4 kPa. These findings provide insights into the impact of pressure on touch DNA deposition, and suggest that pressure is a key variable for crime scene investigators and forensic examiners to consider when prioritising items/surfaces that are likely to produce successful touch DNA results during a criminal investigation

    Appearance and Dynamics of Helical Flux Tubes under Electron Cyclotron Resonance Heating in the Core of KSTAR Plasmas

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    Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n = 1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n = 1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two currentcarrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.X112217Ysciescopu

    On the stability of high-speed milling with spindle speed variation

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    Spindle speed variation is a well-known technique to suppress regenerative machine tool vibrations, but it is usually considered to be effective only for low spindle speeds. In this paper, the effect of spindle speed variation is analyzed in the high-speed domain for spindle speeds corresponding to the first flip (period doubling) and to the first Hopf lobes. The optimal amplitudes and frequencies of the speed modulations are computed using the semidiscre- tization method. It is shown that period doubling chatter can effectively be suppressed by spindle speed variation, although, the technique is not effective for the quasiperiodic chatter above the Hopf lobe. The results are verified by cutting tests. Some special cases are also discussed where the practical behavior of the system differs from the predicted one in some ways. For these cases, it is pointed out that the concept of stability is understood on the scale of the principal period of the system—that is, the speed modulation period for variable spindle speed machining and the tooth passing period for constant spindle speed machining

    Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model

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    Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions

    Aerobic Exercise Training and In Vivo Akt Activation Counteract Cancer Cachexia by Inducing a Hypertrophic Profile through eIF-2α Modulation

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    Cancer cachexia is a multifactorial and devastating syndrome characterized by severe skeletal muscle mass loss and dysfunction. As cachexia still has neither a cure nor an effective treatment, better understanding of skeletal muscle plasticity in the context of cancer is of great importance. Although aerobic exercise training (AET) has been shown as an important complementary therapy for chronic diseases and associated comorbidities, the impact of AET on skeletal muscle mass maintenance during cancer progression has not been well documented yet. Here, we show that previous AET induced a protective mechanism against tumor-induced muscle wasting by modulating the Akt/mTORC1 signaling and eukaryotic initiation factors, specifically eIF2-α. Thereafter, it was determined whether the in vivo Akt activation would induce a hypertrophic profile in cachectic muscles. As observed for the first time, Akt-induced hypertrophy was able and sufficient to either prevent or revert cancer cachexia by modulating both Akt/mTORC1 pathway and the eIF-2α activation, and induced a better muscle functionality. These findings provide evidence that skeletal muscle tissue still preserves hypertrophic potential to be stimulated by either AET or gene therapy to counteract cancer cachexia

    Technical and Clinical Outcome of Talent versus Endurant Endografts for Endovascular Aortic Aneurysm Repair

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    The technical evolution of endografts for the interventional management of infrarenal abdominal aortic aneurysms (AAA) has allowed a continuous expansion of indications. This study compares the established Talent endograft with its successor, the Endurant endograft, taking individual aortoiliac anatomy into account.From June 2007 to December 2010, 35 patients with AAA were treated with a Talent endograft (33 men) and 36 patients with an Endurant endograft (34 men). Aortoiliac anatomy was evaluated in detail using preinterventional computed tomography angiography. The 30-day outcome of both groups were compared regarding technical and clinical success as well as complications including endoleaks.The Endurant group included more patients with unfavorable anatomy (kinking of pelvic arteries, p = 0.017; shorter proximal neck, p = 0.084). Primary technical success was 91.4% in the Talent group and 100% in the Endurant group (p = 0.115). Type 1 endoleaks occurred in 5.7% of patients in the Talent group and in 2.8% of those in the Endurant group (p = 0.614). Type 3 endoleaks only occurred in the Talent group (2.9% of patients; p = 0.493). Type 2 endoleaks were significantly less common in the Endurant group than in the Talent group (8.3% versus 28.6%; p = 0.035). Rates of major and minor complications were not significantly different between both groups. Primary clinical success was significantly better in the Endurant group (97.2%) than in the Talent group (80.0%) (p = 0.028).Endurant endografts appear to have better technical and clinical outcome in patients with difficult aortoiliac anatomy, significantly reducing the occurrence of type 2 endoleaks

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Right-Wing Politicians Prefer the Emotional Left

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    Physiological research suggests that social attitudes, such as political beliefs, may be partly hard-wired in the brain. Conservatives have heightened sensitivity for detecting emotional faces and use emotion more effectively when campaigning. As the left face displays emotion more prominently, we examined 1538 official photographs of conservative and liberal politicians from Australia, Canada, the United Kingdom and the United States for an asymmetry in posing. Across nations, conservatives were more likely than liberals to display the left cheek. In contrast, liberals were more likely to face forward than were conservatives. Emotion is important in political campaigning and as portraits influence voting decisions, conservative politicians may intuitively display the left face to convey emotion to voters
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