1,216 research outputs found

    Developing New Methods to Quantify Stress in Wildlife Using Liquid Chromatography Tandem Mass Spectrometry

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    Stress levels in wildlife species are an accurate indicator of an animal’s well-being and can reflect decreases in habitat quality. Stress levels can be measured by the presence of the stress response hormones cortisol, cortisone, and corticosterone. Analysis of these stress hormones in fecal samples has been widely used because feces can be easily obtained and non-invasively collected in the field. Methods of detecting stress levels from fecal samples of wildlife species are currently limited to enzyme immunoassay testing. This method uses antibodies to bind to target stress hormones. However, immunoassay testing can be time consuming and very expensive2. We propose that Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) offers a new method to quantify levels of the stress hormones from fecal samples that is less expensive and time consuming than traditional immunoassays1. As part of the Idaho Science Talent Expansion Program (STEP), we are developing a simple, accurate, and relatively inexpensive method to detect stress hormones in fecal samples from free-ranging pygmy rabbits (Brachylagus idahoensis) and sage grouse (Centrocercus urophasianus) using LC-MS/MS

    Real-time Automatic M-mode Echocardiography Measurement with Panel Attention from Local-to-Global Pixels

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    Motion mode (M-mode) recording is an essential part of echocardiography to measure cardiac dimension and function. However, the current diagnosis cannot build an automatic scheme, as there are three fundamental obstructs: Firstly, there is no open dataset available to build the automation for ensuring constant results and bridging M-mode echocardiography with real-time instance segmentation (RIS); Secondly, the examination is involving the time-consuming manual labelling upon M-mode echocardiograms; Thirdly, as objects in echocardiograms occupy a significant portion of pixels, the limited receptive field in existing backbones (e.g., ResNet) composed from multiple convolution layers are inefficient to cover the period of a valve movement. Existing non-local attentions (NL) compromise being unable real-time with a high computation overhead or losing information from a simplified version of the non-local block. Therefore, we proposed RAMEM, a real-time automatic M-mode echocardiography measurement scheme, contributes three aspects to answer the problems: 1) provide MEIS, a dataset of M-mode echocardiograms for instance segmentation, to enable consistent results and support the development of an automatic scheme; 2) propose panel attention, local-to-global efficient attention by pixel-unshuffling, embedding with updated UPANets V2 in a RIS scheme toward big object detection with global receptive field; 3) develop and implement AMEM, an efficient algorithm of automatic M-mode echocardiography measurement enabling fast and accurate automatic labelling among diagnosis. The experimental results show that RAMEM surpasses existing RIS backbones (with non-local attention) in PASCAL 2012 SBD and human performances in real-time MEIS tested. The code of MEIS and dataset are available at https://github.com/hanktseng131415go/RAME

    Non-ideal optical isotropy of blue phase liquid crystal

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    Since 1981, blue phase liquid crystal (BPLC) was regarded as optical isotropy and high contrast ratio (CR) should be achieved easily. However, low CR of BPLC display was reported in all literatures. Here, we show BPLC is non-ideal optical isotropy which leads to poor CR. In our report, BPLC not only revealed primary structure of double-twist cylinder and secondary structure of lattice but also revealed tertiary structure of self-alignment on electrode surface. This finding will be useful to improve CR and inspire researches in display industry and academics

    Quantum Field Theoretical Description of Unstable Behavior of Trapped Bose-Einstein Condensates with Complex Eigenvalues of Bogoliubov-de Gennes Equations

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    The Bogoliubov-de Gennes equations are used for a number of theoretical works on the trapped Bose-Einstein condensates. These equations are known to give the energies of the quasi-particles when all the eigenvalues are real. We consider the case in which these equations have complex eigenvalues. We give the complete set including those modes whose eigenvalues are complex. The quantum fields which represent neutral atoms are expanded in terms of the complete set. It is shown that the state space is an indefinite metric one and that the free Hamiltonian is not diagonalizable in the conventional bosonic representation. We introduce a criterion to select quantum states describing the metastablity of the condensate, called the physical state conditions. In order to study the instability, we formulate the linear response of the density against the time-dependent external perturbation within the regime of Kubo's linear response theory. Some states, satisfying all the physical state conditions, give the blow-up and damping behavior of the density distributions corresponding to the complex eigenmodes. It is qualitatively consistent with the result of the recent analyses using the time-dependent Gross-Pitaevskii equation.Comment: 29 page

    Designing physical activity environments to accrue physical and psychological effects

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    Understanding how best to accrue benefits from designing physical activity and exercise programmes is needed to tackle global health problems related to physical inactivity and poor mental health. Some studies have implicated an important role for green exercise and physical activity, but there is a lack of clarity in current research. Therefore, more work is needed to understand how to design green physical activity and exercise environments that afford (invite) physical and psychological benefits to individuals. We examined whether exercising while viewing a dynamic or static image of a scene from nature would offer different affordances (invitations for behaviours to emerge), compared to the common conditions of self-selected entertainment. For this purpose, 30 participants (18 males and 12 females; age 27.5 ± 9 yrs; mass 67.6 ± 11.1 kg; stature 173.7 ± 8.2 cm) exercised in three experimental conditions in a counterbalanced design while: (i) viewing a video of a green environment, (ii) viewing a single static image of the green environment; and (iii), when using typical self-selected entertainment without viewing images of nature. A twenty-minute treadmill run was undertaken at the participants’ own self-selected speed in a laboratory while energy expenditure and psychological states (using PANAS) were assessed. Results showed no differences in energy expenditure (p > .05) or negative affect (p > .05) between conditions. However, data revealed significant differences in positive affect when participants ran with a static image and their own entertainment compared to running with a dynamic image. Results revealed how differences in affordances designed into physical activity environments can shape psychological states that emerge during exercise. Further research is needed on affordance design in physical activity and exercise by engineers, designers, planners and psychologists to explore effects of a range of simulated environments, with different target groups, such as fit and unfit individuals, elderly and children

    Stabilization and pumping of giant vortices in dilute Bose-Einstein condensates

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    Recently, it was shown that giant vortices with arbitrarily large quantum numbers can possibly be created in dilute Bose-Einstein condensates by cyclically pumping vorticity into the condensate. However, multiply quantized vortices are typically dynamically unstable in harmonically trapped nonrotated condensates, which poses a serious challenge to the vortex pump procedure. In this theoretical study, we investigate how the giant vortices can be stabilized by the application of a Gaussian potential peak along the vortex core. We find that achieving dynamical stability is feasible up to high quantum numbers. To demonstrate the efficiency of the stabilization method, we simulate the adiabatic creation of an unsplit 20-quantum vortex with the vortex pump.Comment: 8 pages, 6 figures; to be published in J. Low Temp. Phys., online publication available at http://dx.doi.org/10.1007/s10909-010-0216-

    Synthesis and characterization of new fluorescent two-photon absorption chromophores{

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    A series of dipolar and quadrupolar type two-photon absorption (TPA) compounds has been synthesized and TPA cross sections (s) were measured by Ti:sapphire femtosecond laser excitation fluorescence (l = 800 nm). Among them, the compound ) can be achieved. One quadrupolar molecule (13) possessing an arylamine donor and a pyridazine acceptor has both a high s value (1442 GM) and s/MW (1.97 GM/g)

    Vortices in polariton OPO superfluids

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    This chapter reviews the occurrence of quantised vortices in polariton fluids, primarily when polaritons are driven in the optical parametric oscillator (OPO) regime. We first review the OPO physics, together with both its analytical and numerical modelling, the latter being necessary for the description of finite size systems. Pattern formation is typical in systems driven away from equilibrium. Similarly, we find that uniform OPO solutions can be unstable to the spontaneous formation of quantised vortices. However, metastable vortices can only be injected externally into an otherwise stable symmetric state, and their persistence is due to the OPO superfluid properties. We discuss how the currents charactering an OPO play a crucial role in the occurrence and dynamics of both metastable and spontaneous vortices.Comment: 40 pages, 16 figure
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