1,337 research outputs found

    Microfluidic Electrical Impedance Spectroscopy

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    The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were introduced into the device, where changes in impedance were seen across multiple frequencies, indicating that the device is capable of detecting the presence of biologic elements within a system. Cell measurements were performed using NIH-3T3 fibroblasts

    CDS wide slit time-series of EUV coronal bright points

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    Wide slit (90" x 240" ) movies of four Extreme Ultraviolet coronal bright points (BPs) obtained with the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SoHO) have been inspected. The wavelet analysis of the He I 584.34 Å, O V 629.73 Å and Mg VII/IX 368 Å time-series confirms the oscillating nature of the BPs, with periods ranging between 600 and 1100 s. In one case we detect periods as short as 236 s. We suggest that these oscillations are the same as those seen in the chromospheric network and that a fraction of the network bright points are most likely the cool footpoints of the loops comprising coronal bright points. These oscillations are interpreted in terms of global acoustic modes of the closed magnetic structures associated with BPs

    Excited states in lattice QCD with the stochastic LapH method

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    Progress in computing the spectrum of excited baryons and mesons in lattice QCD is described. Results in the zero-momentum bosonic I=1/2, S=1, T1u symmetry sector of QCD using a correlation matrix of 58 operators are presented. All needed Wick contractions are efficiently evaluated using a stochastic method of treating the low-lying modes of quark propagation that exploits Laplacian Heaviside quark-field smearing. Level identification using probe operators is discussed.Comment: 4 pages, 3 figures, talk presented at the 13th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU 2013), Sept 30 - Oct 4, 2013, Rome, Ital

    The Yield of Essential Oils in Melaleuca alternifolia (Myrtaceae) Is Regulated through Transcript Abundance of Genes in the MEP Pathway

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    Medicinal tea tree (Melaleuca alternifolia) leaves contain large amounts of an essential oil, dominated by monoterpenes. Several enzymes of the chloroplastic methylerythritol phosphate (MEP) pathway are hypothesised to act as bottlenecks to the production of monoterpenes. We investigated, whether transcript abundance of genes encoding for enzymes of the MEP pathway were correlated with foliar terpenes in M. alternifolia using a population of 48 individuals that ranged in their oil concentration from 39 -122 mg x g DM(-1). Our study shows that most genes in the MEP pathway are co-regulated and that the expression of multiple genes within the MEP pathway is correlated with oil yield. Using multiple regression analysis, variation in expression of MEP pathway genes explained 87% of variation in foliar monoterpene concentrations. The data also suggest that sesquiterpenes in M. alternifolia are synthesised, at least in part, from isopentenyl pyrophosphate originating from the plastid via the MEP pathway.The work was funded by an Australian Research Council Linkage grant to W.J.F. (LP110100184) with the active partnership of the Australian Tea Tree Industry Association (ATTIA) and a supplementary grant from the Rural Industries Research and Development Corporation. The funders had no role is study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Two-Legged Hopping in Autism Spectrum Disorders

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    Sensory processing deficits are common within autism spectrum disorders (ASD). Deficits have a heterogeneous dispersion across the spectrum and multimodal processing tasks are thought to magnify integration difficulties. Two-legged hopping in place in sync with an auditory cue (2.3, 3.0 Hz) was studied in a group of six individuals with expressive language impaired ASD (ELI-ASD) and an age-matched control group. Vertical ground reaction force data were collected and discrete Fourier transforms were utilized to determine dominant hopping cadence. Effective leg stiffness was computed through a mass-spring model representation. The ELI-ASD group were unsuccessful in matching their hopping cadence (2.21 ± 0.30 hops·s−1, 2.35 ± 0.41 hops·s−1) to either auditory cue with greater deviations at the 3.0 Hz cue. In contrast, the control group was able to match hopping cadence (2.35 ± 0.06 hops·s−1, 3.02 ± 0.10 hops·s−1) to either cue via an adjustment of effective leg stiffness. The ELI-ASD group demonstrated a varied response with an interquartile range (IQR) in excess of 0.5 hops·s−1 as compared to the control group with an IQR \u3c 0.03 hops·s−1. Several sensorimotor mechanisms could explain the inability of participants with ELI-ASD to modulate motor output to match an external auditory cue. These results suggest that a multimodal gross motor task can (1) discriminate performance among a group of individuals with severe autism, and (2) could be a useful quantitative tool for evaluating motor performance in individuals with ASD individuals

    Gait Analysis of Teenagers and Young Adults Diagnosed with Autism & Severe Verbal Communication Disorders

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    Both movement differences and disorders are common within autism spectrum disorders (ASD). These differences have wide and heterogeneous variability among different ages and sub-groups all diagnosed with ASD. Gait was studied in a more homogeneously identified group of nine teenagers and young adults who scored as “severe” in both measures of verbal communication and overall rating of Autism on the Childhood Autism Rating Scales (CARS). The ASD individuals were compared to a group of typically developing university undergraduates of similar ages. All participants walked a distance of 6-meters across a GAITRite (GR) electronic walkway for six trials. The ASD and comparison groups differed widely on many spatiotemporal aspects of gait including: step and stride length, foot positioning, cadence, velocity, step time, gait cycle time, swing time, stance time, and single and double support time. Moreover, the two groups differed in the percentage of the total gait cycle in each of these phases. The qualitative rating of “Body Use” on the CARS also indicated severe levels of unusual body movement for all of the ASD participants. These findings demonstrate that older teens and young adults with “severe” forms of Verbal Communication Impairments and Autism differ widely in their gait from typically developing individuals. The differences found in the current investigation are far more pronounced compared to previous findings with younger and/or less severely involved individuals diagnosed with ASD as compared to typically developing controls. As such, these data may be a useful anchor-point in understanding the trajectory of development of gait specifically and motor functions generally.

    Accuracy of Voice-Announcement Pedometers for Youth with Visual Impairment

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    Thirty-five youth with visual impairments (13.5 plus or minus 2.1 yrs, 13 girls and 22 boys) walked four 100-meter distances while wearing two units (right and left placement) of three brands of voice-announcement (VA) pedometers (Centrios[TM] Talking Pedometer, TALKiNG Pedometer, and Sportline Talking Calorie Pedometer 343) and a reference pedometer (NL2000). Registered pedometer steps for each trial were recorded, compared to actual steps assessed via digital video. Inter-unit agreement between right and left VA pedometer placement was low (ICC range 0.37 to 0.76). A systematic error was observed for the VA pedometers on the left placement (error range 5.6% to 12.2%), while right placement VA pedometers were at or below plus or minus 3% from actual steps (range 2.1% to 3.3%). The reference pedometer was unaffected by placement (ICC 0.98, error approximately 1.4%). Overall, VA pedometers demonstrated acceptable accuracy for the right placement, suggesting this position is necessary for youth with visual impairments. (Contains 3 tables and 2 figures.
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