403 research outputs found

    A Reanalysis of the Osteological and Cultural Remains from Ausmus Burial Cave, Claiborne County, Tennessee (3CE20)

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    Few excavations or analyses of remains from burial caves have been published. Those that are reported are frequently cited without considering context of the original excavations and analyses. This consideration is important, because previously collected data would be interpreted differently using modern approaches. This study is a reanalysis of Ausmus Burial Cave (3CE20), Claiborne County, Tennessee. The site was excavated in the 1930\u27s, and the authors\u27 methodology, conclusion, and conjectures reflect this time. Their hypothesis was that the skeletons represented intruders in the area, they were killed in battle, and their bodies were dropped unceremoniously in the pit cave. This reanalysis: (1) describes the data more completely and from current perspectives, (2) responds to questions concerning human interment in pit caves, and (3) includes additional skeletal material, discovered in 1975. It is concluded that at least 25 Late Woodland/Early Mississippian individuals were recovered from 3CE20. They represent both genders and all age groups, except fetal. There is no statistical difference in age distribution between 3CE20 and other Norris Basin sites of the same time period. The same results are found when 3CE20 individuals are compared to the Late Woodland Hamilton component individuals of Hiwassee Island (42MG31, 46MG31, 47MG31, 73MG31, 78MG31). Statistically significant differences in gender exist between 3CE20 and a 50:50 ratio. However, this result may be spurious. The paleopathological analysis reveals that several pathologies were undetected in the original report or were misdiagnosed. These findings are significant and place serious doubt upon the original interpretation

    Experimental realization of an achromatic magnetic mirror based on metamaterials

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    Our work relates to the use of metamaterials engineered to realize a meta-surface approaching the exotic properties of an ideal object not observed in nature, a ‘magnetic mirror’. Previous realizations were based on resonant structures which implied narrow bandwidths and large losses. The working principle of our device is ideally frequency-independent, it does not involve resonances and it does not rely on a specific technology. The performance of our prototype, working at millimetre wavelengths, has never been achieved before and it is superior to any other device reported in the literature, both in the microwave and optical regions. The device inherently has large bandwidth (144%), low losses (<1 %) and is almost independent of incidence-angle and polarization-state and thus approaches the behaviour of an ideal magnetic mirror. Applications of magnetic mirrors range from low-profile antennas, absorbers to optoelectronic devices. Our device can be realised using different technologies to operate in other spectral regions

    Gene expression profiling in the lungs of pigs with different susceptibilities to Glässer's disease.

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    BACKGROUND: Haemophilus parasuis is the causative agent of Glässer's disease in pigs. Currently, little is known about the molecular mechanisms that contribute to disease susceptibility. This study used a porcine oligonucleotide microarray to identify genes that were differentially expressed (DE) in the lungs of colostrum-deprived animals previously characterized as being either 'Fully Resistant' (FR) or 'Susceptible' to infection by H. parasuis in a bacterial challenge experiment. RESULTS: Gene expression profiles of 'FR' and 'Susceptible' animals were obtained by the identification of genes that were differentially expressed between each of these groups and mock-inoculated 'Control' animals. At 24 hours post-inoculation, a total of 21 and 58 DE genes were identified in 'FR' and 'Susceptible' animals respectively. At 72 hours, the numbers of genes were 20 and 347 respectively. 'FR' animals at 24 hours exhibited an increased expression of genes encoding extracellular matrix and TGF-beta signalling components, possibly indicative of tissue repair following the successful early resolution of infection. The gene expression profile of 'FR' animals at 72 hours supported the hypothesis that higher levels of antibacterial activity were responsible for the 'FR' phenotype, possibly due to an increase in natural immunoglobulin A and decrease in signalling by the immunoregulatory transcription factor peroxisome proliferator-activated receptor gamma (PPAR-gamma). The expression profile of 'Susceptible' animals at both time-points was characterized by an imbalance in signalling between pro and anti-inflammatory cytokines and an increased expression of genes involved in biological processes associated with inflammation. These include the pro-inflammatory cytokine genes resistin (RETN) and interleukin 1-beta (IL1B). At 72 hours, a reduction in the expression of genes involved in antigen presentation by both MHC class I and II molecules was observed, which could have contributed to the inability of 'Susceptible' animals to clear infection. CONCLUSIONS: This study is the first to have identified discrete sets of DE genes in pigs of differing susceptibility to H. parasuis infection. Consequently, several candidate genes and pathways for disease resistance or susceptibility phenotypes have been identified. In addition, the findings have shed light on the molecular pathology associated with Glässer's disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Gene expression profiling in the lungs of pigs with different susceptibilities to Glässer's disease

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    <p>Abstract</p> <p>Background</p> <p><it>Haemophilus parasuis </it>is the causative agent of Glässer's disease in pigs. Currently, little is known about the molecular mechanisms that contribute to disease susceptibility. This study used a porcine oligonucleotide microarray to identify genes that were differentially expressed (DE) in the lungs of colostrum-deprived animals previously characterized as being either 'Fully Resistant' (FR) or 'Susceptible' to infection by <it>H. parasuis </it>in a bacterial challenge experiment.</p> <p>Results</p> <p>Gene expression profiles of 'FR' and 'Susceptible' animals were obtained by the identification of genes that were differentially expressed between each of these groups and mock-inoculated 'Control' animals. At 24 hours post-inoculation, a total of 21 and 58 DE genes were identified in 'FR' and 'Susceptible' animals respectively. At 72 hours, the numbers of genes were 20 and 347 respectively. 'FR' animals at 24 hours exhibited an increased expression of genes encoding extracellular matrix and TGF-β signalling components, possibly indicative of tissue repair following the successful early resolution of infection. The gene expression profile of 'FR' animals at 72 hours supported the hypothesis that higher levels of antibacterial activity were responsible for the 'FR' phenotype, possibly due to an increase in natural immunoglobulin A and decrease in signalling by the immunoregulatory transcription factor peroxisome proliferator-activated receptor gamma (PPAR-γ). The expression profile of 'Susceptible' animals at both time-points was characterized by an imbalance in signalling between pro and anti-inflammatory cytokines and an increased expression of genes involved in biological processes associated with inflammation. These include the pro-inflammatory cytokine genes resistin (<it>RETN</it>) and interleukin 1-beta (<it>IL1B</it>). At 72 hours, a reduction in the expression of genes involved in antigen presentation by both MHC class I and II molecules was observed, which could have contributed to the inability of 'Susceptible' animals to clear infection.</p> <p>Conclusions</p> <p>This study is the first to have identified discrete sets of DE genes in pigs of differing susceptibility to <it>H. parasuis </it>infection. Consequently, several candidate genes and pathways for disease resistance or susceptibility phenotypes have been identified. In addition, the findings have shed light on the molecular pathology associated with Glässer's disease.</p

    Transmission Properties of Subwavelength Planar Fractals for THz Wavelengths

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    We investigate the transmission properties of planar H fractal structures in THz range. 3D EM simulations using HFSS are used to design the parameters of the fractals and to evaluate the optical properties. We observe the transmission spectra with pass bands and stop bands, which show the subwavelength transmission through the non-metallic gaps. This unique transmission property through subwavelength apertures makes it potentially useful frequency selective components in THz region. We experimentally demonstrate its behavior by designing and fabricating four prototype planar fractals in the range of 0-1.5THz and characterize using a polarizing Fourier transform spectrometer. We find good agreement between the models and measurements

    The Simons Observatory: Science goals and forecasts

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    The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping ≈ 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of σ(r)=0.003. The large aperture telescope will map ≈ 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources

    Super-capacitive patches and their use in low-pass filters and artificial dielectrics

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    The use of capacitive metal meshes consisting of square patches is well established in the design of millimeter-wave optical devices such as filters, half-wave plates, and graded-index lenses. The main property of these meshes, the capacitance, is controlled by the size of the square patch in the mesh’s unit cell up to a limit imposed by the minimum feature size of the manufacturing process. We report the results of a study into the feasibility of increasing the capacitance beyond this limit by extending fingers into the adjacent unit cell. This is shown to increase the range of admittance characteristics available with the meshes and how this might be useful for the implementation of low-pass filters and artificial dielectrics is demonstrated

    Mesh low-pass filters for millimeter-wave applications: is the square capacitive shape optimal?

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    The use of mesh filters for millimeter-wave applications using capacitive and inductive grids is well known, and they are widely used in cosmic microwave background instrumentation. We report on an investigation into whether the capacitive square shape typically used in low-pass filter designs could be improved. The microgenetic algorithm and the finite-difference time-domain, and electromagnetic modeling method were used to look for shape variations to the standard square shape. Any shape changes discovered were then analyzed to establish which variations had the most effect. We show that improvements found using pixelated patterns evolved by the genetic algorithm were somewhat mixed

    Exploring cosmic origins with CORE: survey requirements and mission design

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    Future observations of cosmic microwave background (CMB) polarisation have the potential to answer some of the most fundamental questions of modern physics and cosmology. In this paper, we list the requirements for a future CMB polarisation survey addressing these scientific objectives, and discuss the design drivers of the CORE space mission proposed to ESA in answer to the "M5" call for a medium-sized mission. The rationale and options, and the methodologies used to assess the mission's performance, are of interest to other future CMB mission design studies. CORE is designed as a near-ultimate CMB polarisation mission which, for optimal complementarity with ground-based observations, will perform the observations that are known to be essential to CMB polarisation scienceand cannot be obtained by any other means than a dedicated space mission

    Mapping the hot gas temperature in galaxy clusters using X-ray and Sunyaev-Zel'dovich imaging

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    We propose a method to map the temperature distribution of the hot gas in galaxy clusters that uses resolved images of the thermal Sunyaev-Zel’dovich (tSZ) effect in combination with X-ray data. Application to images from the New IRAM KIDs Array (NIKA) and XMM-Newton allows us to measure and determine the spatial distribution of the gas temperature in the merging cluster MACS J0717.5+3745, at z = 0.55. Despite the complexity of the target object, we find a good morphological agreement between the temperature maps derived from X-ray spectroscopy only – using XMM-Newton (TXMM) and Chandra (TCXO) – and the new gas-mass-weighted tSZ+X-ray imaging method (TSZX). We correlate the temperatures from tSZ+X-ray imaging and those from X-ray spectroscopy alone and find that TSZX is higher than TXMM and lower than TCXO by ~ 10% in both cases. Our results are limited by uncertainties in the geometry of the cluster gas, contamination from kinetic SZ (~10%), and the absolute calibration of the tSZ map (7%). Investigation using a larger sample of clusters would help minimise these effects
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