107 research outputs found

    Description of a new approach for great auricular and auriculotemporal nerve blocks: A cadaveric study in foxes and dogs

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    Otitis externa is a painful condition that may require surgical intervention in dogs. A balanced analgesia protocol should combine systemic analgesic agents and local anaesthesia techniques. The aim of the study was to find anatomical landmarks for the great auricular and the auriculotemporal nerves that transmit nociceptive information from the ear pinna and to develop the optimal technique for a nerve block. The study consisted of two phases. In phase I, one fox cadaver was used for dissection and anatomical localization of the auricular nerves to derive landmarks for needle insertion. Eight fox cadavers were subsequently used to evaluate the accuracy of the technique by injecting methylene blue bilaterally. In phase II findings from phase I were applied in four Beagle canine cadavers. A block was deemed successful if more than 0.6 cm of the nerve's length was stained. Successful great auricular nerve block was achieved by inserting the needle superficially along the wing of the atlas with the needle pointing towards the jugular groove. For the auriculotemporal nerve block the needle was inserted perpendicular to the skin at the caudal lateral border of the zygomatic arch, close to the temporal process. The overall success rate was 24 out of 24 (100%) and 22 out of 24 (91%) for the great auricular and the auriculotemporal nerves, respectively, while the facial nerve was stained on three occasions. Our results suggest that it is feasible to achieve a block of the auricular nerves, based on anatomical landmarks, without concurrently affecting the facial nerv

    Balmer-dominated shocks in Tycho's SNR: omnipresence of CRs

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    We present wide-field, spatially and highly resolved spectroscopic observations of Balmer filaments in the northeastern rim of Tycho's supernova remnant in order to investigate the signal of cosmic-ray (CR) acceleration. The spectra of Balmer-dominated shocks (BDSs) have characteristic narrow (FWHM \sim 10 kms1^{-1}) and broad (FWHM \sim 1000 kms1^{-1}) Hα\alpha components. CRs affect the Hα\alpha-line parameters: heating the cold neutrals in the interstellar medium results in broadening of the narrow Hα\alpha-line width beyond 20 kms1^{-1}, but also in reduction of the broad Hα\alpha-line width due to energy being removed from the protons in the post-shock region. For the first time we show that the width of the narrow Hα\alpha line, much larger than 20 kms1^{-1}, is not a resolution or geometric effect nor a spurious result of a neglected intermediate (FWHM \sim 100 kms1^{-1}) component resulting from hydrogen atoms undergoing charge exchange with warm protons in the broad-neutral precursor. Moreover, we show that a narrow line width \gg 20 kms1^{-1} extends across the entire NE rim, implying CR acceleration is ubiquitous, and making it possible to relate its strength to locally varying shock conditions. Finally, we find several locations along the rim, where spectra are significantly better explained (based on Bayesian evidence) by inclusion of the intermediate component, with a width of 180 kms1^{-1} on average.Comment: Proceeding for contributed talk at the IAU Symposium No. 331: "SN 1987A, 30 years later - Cosmic Rays and Nuclei from Supernovae and their Aftermaths", 2017, La Reunion Island; References correcte

    Balmer filaments in Tycho's supernova remnant: an interplay between cosmic-ray and broad-neutral precursors

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    We present Hα\alpha spectroscopic observations and detailed modelling of the Balmer filaments in the supernova remnant Tycho. We used Galaxy Hα\alpha Fabry-P\'erot Spectrometer on the William Herschel Telescope with a 3.4'×\times3.4' field-of-view, 0.2" pixel scale and \sigma_\rm{instr}=8.1 km/s resolution at 1" seeing for 10\sim10 hours, resulting in 82 spatial-spectral bins that resolve the narrow Hα\alpha line in the entire Tycho's northeastern rim. For the first time, we can mitigate artificial line broadening from unresolved differential motion, and probe Hα\alpha emission parameters in varying shock and ambient medium conditions. Broad Hα\alpha line remains unresolved within spectral coverage of 392 km/s. We employed Bayesian inference to obtain reliable parameter confidence intervals, and quantify the evidence for models with multiple line components. The median Hα\alpha narrow-line full-width at half-maximum of all bins and models is W_\rm{NL}=(54.8\pm1.8) km/s at the 95%95\% confidence level, varying within [35, 72] km/s between bins and clearly broadened compared to the intrinsic (thermal) 20\approx20 km/s. Possible line splits are accounted for, significant in 18%\approx18\% of the filament, and presumably due to remaining projection effects. We also find wide-spread evidence for intermediate-line emission of a broad-neutral precursor, with median W_\rm{IL}=(180\pm14) km/s (95%95\% confidence). Finally, we present a measurement of the remnant's systemic velocity, V_\rm{LSR}=-34 km/s, and map differential line-of-sight motions. Our results confirm the existence and interplay of shock precursors in Tycho's remnant. In particular, we show that suprathermal narrow-line emission is near-universal in Tycho and that, in absence of an alternative explanation, collisionless supernova remnant shocks constitute a viable acceleration source for Galactic TeV Cosmic-Ray protons.Comment: 36 pages, 17 figures, 5 tables, Paper accepted for publication in the Astrophysical Journal; References correcte

    Human fetal neuroblast and neuroblastoma transcriptome analysis confirms neuroblast origin and highlights neuroblastoma candidate genes

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    BACKGROUND: Neuroblastoma tumor cells are assumed to originate from primitive neuroblasts giving rise to the sympathetic nervous system. Because these precursor cells are not detectable in postnatal life, their transcription profile has remained inaccessible for comparative data mining strategies in neuroblastoma. This study provides the first genome-wide mRNA expression profile of these human fetal sympathetic neuroblasts. To this purpose, small islets of normal neuroblasts were isolated by laser microdissection from human fetal adrenal glands. RESULTS: Expression of catecholamine metabolism genes, and neuronal and neuroendocrine markers in the neuroblasts indicated that the proper cells were microdissected. The similarities in expression profile between normal neuroblasts and malignant neuroblastomas provided strong evidence for the neuroblast origin hypothesis of neuroblastoma. Next, supervised feature selection was used to identify the genes that are differentially expressed in normal neuroblasts versus neuroblastoma tumors. This approach efficiently sifted out genes previously reported in neuroblastoma expression profiling studies; most importantly, it also highlighted a series of genes and pathways previously not mentioned in neuroblastoma biology but that were assumed to be involved in neuroblastoma pathogenesis. CONCLUSION: This unique dataset adds power to ongoing and future gene expression studies in neuroblastoma and will facilitate the identification of molecular targets for novel therapies. In addition, this neuroblast transcriptome resource could prove useful for the further study of human sympathoadrenal biogenesis

    Access to primary care for socio-economically disadvantaged older people in rural areas: A realist review

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    Objective: The aim of this review is to identify and understand the contexts that effect access to high quality primary care for socio-economically disadvantaged older people in rural areas. Design: A realist review Data sources: MEDLINE and EMBASE electronic databases and grey literature (from inception to Dec 2014). Eligibility criteria for selecting studies: Broad inclusion criteria were used to allow articles which were not specific, but might be relevant to the population of interest to be considered. Studies meeting the inclusion criteria were assessed for rigour and relevance and coded for concepts relating to context, mechanism or outcome. Analysis: An overarching patient pathway was generated and used as the basis to explore contexts, causal mechanisms and outcomes. Results: 162 articles were included. Most were from the USA or UK, cross sectional in design and presented subgroup data by age, rurality or deprivation. From these studies a patient pathway was generated which included seven steps (problem identified, decision to seek help, actively seek help, obtain appointment, get to appointment, primary care interaction and outcome). Important contexts were stoicism, education status, expectations of ageing, financial resources, understanding the health care system, access to suitable transport, capacity in primary care, the booking system and experience of health care. Prominent causal mechanisms were health literacy, perceived convenience, patient empowerment and responsiveness of the practice. Conclusions: Socio-economically disadvantaged older people in rural areas face personal, community and health care barriers that limit their access to primary care. Initiatives should be targeted at local contextual factors to help individuals recognise problems, feel welcome, navigate the health care system, book appointments easily, access appropriate transport and have sufficient time with professional staff to improve their experience of health care; all of which will require dedicated primary care resources

    Balmer Filaments in Tycho's Supernova Remnant: An Interplay between Cosmic-ray and Broad-neutral Precursors

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    We present H alpha spectroscopic observations and detailed modeling of the Balmer filaments in the supernova remnant (SNR) Tycho (SN 1572). We used GH alpha FaS (Galaxy H alpha Fabry-Perot Spectrometer) on the William Herschel Telescope with a 3'.4 x 3'.4 field of view, 0 ''.2 pixel scale, and sigma(instr) = 8.1 km s(-1) resolution at 1 '' seeing for similar to 10. hr, resulting in 82 spatial-spectral bins that resolve the narrow H alpha line in the entire SN 1572 northeastern rim. For the first time, we can therefore mitigate artificial line broadening from unresolved differential motion and probe H alpha emission parameters in varying shock and ambient medium conditions. Broad H alpha line remains unresolved within spectral coverage of 392 km s-1. We employed Bayesian inference to obtain reliable parameter confidence intervals and to quantify the evidence for models with multiple line components. The median H alpha narrow-line (NL) FWHM of all bins and models is W-NL = (54.8 +/- 1.8) km s(-1) at the 95% confidence level, varying within [35, 72] km s(-1) between bins and clearly broadened compared to the intrinsic (thermal) approximate to 20 km s(-1). Possible line splits are accounted for, significant in approximate to 18% of the filament, and presumably due to remaining projection effects. We also find widespread evidence for intermediate-line emission of a broad-neutral precursor, with a median W-IL =(180 +/- 14) km s(-1) (95% confidence). Finally, we present a measurement of the remnant's systemic velocity, V-LSR = -34 km s(-1), and map differential line-of-sight motions. Our results confirm the existence and interplay of shock precursors in Tycho's remnant. In particular, we show that suprathermal NL emission is near-universal in SN 1572, and that, in the absence of an alternative explanation, collisionless SNR shocks constitute a viable acceleration source for Galactic TeV cosmic-ray protons

    Potential for anthropogenic disturbances to influence evolutionary change in the life history of a threatened salmonid

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    Although evolutionary change within most species is thought to occur slowly, recent studies have identified cases where evolutionary change has apparently occurred over a few generations. Anthropogenically altered environments appear particularly open to rapid evolutionary change over comparatively short time scales. Here, we consider a Pacific salmon population that may have experienced life-history evolution, in response to habitat alteration, within a few generations. Historically, juvenile fall Chinook salmon (Oncorhynchus tshawytscha) from the Snake River migrated as subyearlings to the ocean. With changed riverine conditions that resulted from hydropower dam construction, some juveniles now migrate as yearlings, but more interestingly, the yearling migration tactic has made a large contribution to adult returns over the last decade. Optimal life-history models suggest that yearling juvenile migrants currently have a higher fitness than subyearling migrants. Although phenotypic plasticity likely accounts for some of the change in migration tactics, we suggest that evolution also plays a significant role. Evolutionary change prompted by anthropogenic alterations to the environment has general implications for the recovery of endangered species. The case study we present herein illustrates the importance of integrating evolutionary considerations into conservation planning for species at risk

    The Supercam Instrument Suite on the NASA Mars 2020 Rover: Body Unit and Combined System Tests

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    The SuperCam instrument suite provides the Mars 2020 rover, Perseverance, with a number of versatile remote-sensing techniques that can be used at long distance as well as within the robotic-arm workspace. These include laser-induced breakdown spectroscopy (LIBS), remote time-resolved Raman and luminescence spectroscopies, and visible and infrared (VISIR; separately referred to as VIS and IR) reflectance spectroscopy. A remote micro-imager (RMI) provides high-resolution color context imaging, and a microphone can be used as a stand-alone tool for environmental studies or to determine physical properties of rocks and soils from shock waves of laser-produced plasmas. SuperCam is built in three parts: The mast unit (MU), consisting of the laser, telescope, RMI, IR spectrometer, and associated electronics, is described in a companion paper. The on-board calibration targets are described in another companion paper. Here we describe SuperCam’s body unit (BU) and testing of the integrated instrument. The BU, mounted inside the rover body, receives light from the MU via a 5.8 m optical fiber. The light is split into three wavelength bands by a demultiplexer, and is routed via fiber bundles to three optical spectrometers, two of which (UV and violet; 245–340 and 385–465 nm) are crossed Czerny-Turner reflection spectrometers, nearly identical to their counterparts on ChemCam. The third is a high-efficiency transmission spectrometer containing an optical intensifier capable of gating exposures to 100 ns or longer, with variable delay times relative to the laser pulse. This spectrometer covers 535–853 nm (105–7070 cm−1 Raman shift relative to the 532 nm green laser beam) with 12 cm−1 full-width at half-maximum peak resolution in the Raman fingerprint region. The BU electronics boards interface with the rover and control the instrument, returning data to the rover. Thermal systems maintain a warm temperature during cruise to Mars to avoid contamination on the optics, and cool the detectors during operations on Mars. Results obtained with the integrated instrument demonstrate its capabilities for LIBS, for which a library of 332 standards was developed. Examples of Raman and VISIR spectroscopy are shown, demonstrating clear mineral identification with both techniques. Luminescence spectra demonstrate the utility of having both spectral and temporal dimensions. Finally, RMI and microphone tests on the rover demonstrate the capabilities of these subsystems as well

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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