Publications by authors named "Demers D"

A heavy ion beam probe (HIBP) diagnostic is being developed for studies of plasma equilibrium and turbulence in the optimized Wendelstein 7-X (W7-X) stellarator. Operation of W7-X has experimentally demonstrated that its optimized magnetic field results in improved neoclassical particle confinement and, as a result, turbulence is the predominant cause of energy transport. The HIBP will have the unique ability to provide experimental data needed to complement models of both neoclassical and turbulent transport.

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This article describes the current state of the design of the heavy ion beam probe (HIBP) for Wendelstein 7-X (W7-X). It will be the first HIBP diagnostic on an optimized stellarator and is designed to study electric fields and ion scale turbulence in all W7-X reference magnetic configurations. The use of an existing 2 MV accelerator, located outside of the torus hall, results in the need for a circuitous primary beamline.

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Dry eye is a common cause of ocular pain. The aim of this study was to investigate corneal innervation, ongoing pain, and alterations in corneal afferent phenotypes in a mouse model of severe aqueous tear deficiency. Chronic dry eye was produced by ipsilateral excision of the extra- and intraorbital lacrimal glands in male and female mice.

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A technique for more accurately modeling and improving the spatial resolution of heavy ion beam probe measurements is described. We use a set of particle trajectories to numerically determine the focusing properties of a complicated three-dimensional magnetic field and characterize these properties with a transfer matrix. We then modify the transfer matrix approach of traditional ion optics to include a parameter that describes the ionization location of the detected ions.

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Lacrimal gland excision (LGE) induced dry eye produces more severe corneal damage in female mice, yet signs of LGE-induced ocular pain and anxiety in male and female mice have not been characterized. Excision of either the extraorbital gland (single LGE), or both the extraorbital and intraorbital glands (double LGE) was performed in male and female C57BL/6J mice to induce moderate and severe dry eye. Ongoing pain was assessed by quantifying palpebral opening and evoked nociceptive responses after corneal application of capsaicin and menthol.

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Contemporary speech and language interventions are not limited to disabilities but embrace the pragmatics of communication behaviors from the perspective of functional social participation. Accordingly, current speech and language therapies for deaf and hard-of-hearing children include a broad spectrum of approaches and techniques. This paper explores contemporary approaches and techniques for speech and oral language interventions for deaf and hard-of-hearing children using hearing devices, evidence of efficacy and how they are implemented in diverse clinical practices.

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This study compared the effects of yoga and mindfulness meditation on self-compassion, mindfulness, and perceived stress in college students; and explored mind-body mechanisms and predictors of stress reduction. Student participants ( = 92) were enrolled in either yoga or mindfulness meditation classes at a college in the southern United States from August through May of 2015-2016. Students participated in 50-minute classes twice a week for 10 weeks, completing self-report questionnaires during the 1st and 10th week.

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Purpose The purpose of this systematic review is to identify and evaluate the available scientific evidence on the effectiveness of rehabilitation approaches proposed to children with severe-to-profound prelinguistic deafness on the hearing, speech, and language skills development. Method Databases (PubMed, CINHAL, PsycInfo, Cochrane, ERIC, and EMBASE) were searched with relevant key words (children, deafness, rehabilitation approach, auditory, speech, and language). Studies published between 2000 and 2017 were included.

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Purpose: Lacrimal gland excision (LGE) has been utilized in several studies to model aqueous tear deficiency, yet sex as a biological variable has not been factored in to these reports. This study compared corneal pathology in male and female mice following LGE-induced dry eye.

Methods: An LGE of either the extraorbital lacrimal gland (single LGE) or both the extraorbital and intraorbital lacrimal glands (double LGE) was performed in male and female C57BL/6J and Balb/cJ mice to produce dry eye of graded severity.

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The goal of this work was to develop and normalise an international French version of the AzBio sentence test. A corpus of 1000 sentences was generated. These sentences were recorded with four talkers and processed through a four-channel cochlear implant simulation.

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Sialic acid-binding Ig-like lectin 8 (Siglec-8) is expressed on the surface of human eosinophils, mast cells, and basophils-cells that participate in allergic and other diseases. Ligation of Siglec-8 by specific glycan ligands or antibodies triggers eosinophil death and inhibits mast cell degranulation; consequences that could be leveraged as treatment. However, Siglec-8 is not expressed in murine and most other species, thus limiting preclinical studies in vivo.

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We have developed an ion current measurement instrument with a direct view of a plasma that reduces the particle and radiation-induced noise current it detects by over three orders of magnitude, from tens of microamps to tens of nanoamps. This is accomplished using electric fields, magnetic fields, and physical shielding that limit the flux of particles and radiation into the instrument and suppress the secondary electrons produced within it by particle and radiation impact. Operation of this detector in various configurations, without an ion beam, has allowed identification of the sources of noise current.

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Article Synopsis
  • There is a pressing need for new treatments for infectious diseases, prompting a screening of mangrove-derived endophytic fungi as potential sources of antibiotics.
  • The screening assessed the fungi's effectiveness against various bacterial pathogens and eukaryotic infectious agents, revealing that over 60% of active extracts targeted a single type of pathogen.
  • The study also showed that nearly half of the fungi producing effective extracts did so only after being treated with epigenetic modulators that inhibit histone deacetylases or DNA methyltransferases.
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Secondary electrons emitted when an ion beam impacts a detector can amplify the ion beam signal, but also introduce errors if electrons from one detector propagate to another. A potassium ion beam and a detector comprised of ten impact wires, four split-plates, and a pair of biased electrodes were used to demonstrate that a low-voltage, positive electrode can be used to maintain the beneficial amplification effect while greatly reducing the error introduced from the electrons traveling between detector elements.

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In an axisymmetric plasma, the conservation of canonical angular momentum constrains heavy ion beam probe (HIBP) trajectories such that measurement of the toroidal velocity component of secondary ions provides a localized determination of the poloidal flux at the volume where they originated. We have developed a prototype detector which is designed to determine the beam angle in one dimension through the detection of ion current landing on two parallel planes of detecting elements. A set of apertures creates a pattern of ion current on wires in the first plane and solid metal plates behind them; the relative amounts detected by the wires and plates determine the angle which beam ions enter the detector, which is used to infer the toroidal velocity component.

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The performance of many diagnostic and control systems within fusion and other fields of research are often detrimentally affected by spurious noise signals. This is particularly true for those (such as radiation or particle detectors) working with very small signals. Common sources of radiated and conducted noise in experimental fusion environments include the plasma itself and instrumentation.

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The cytokine gamma interferon (IFN-γ), with antimicrobial and immunoregulatory functions, can be produced by T cells following stimulation through their T cell receptors (TCRs) for antigen. The innate cytokines type 1 IFNs and interleukin-12 (IL-12) can also stimulate IFN-γ production by natural killer (NK) but not naive T cells. High basal expression of signal transducer and activator of transcription 4 (STAT4), used by type 1 IFN and IL-12 to induce IFN-γ as well as CD25, contributes to the NK cell responses.

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Most health research with American Indian and Alaska Native (AI/AN) people has focused on tribal communities on reservation lands. Few studies have been conducted with AI/AN people living in urban settings despite their documented health disparities compared with other urban populations. There are unique considerations for working with this population.

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Heavy ion beam probes have been installed on a variety of toroidal devices, but the first and only application on a reversed field pinch is the diagnostic on the Madison Symmetric Torus. Simultaneous measurements of spatially localized equilibrium potential and fluctuations of density and potential, previously inaccessible in the core of the reversed field pinch (RFP), are now attainable. These measurements reflect the unique strength of the heavy ion beam probe (HIBP) diagnostic.

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The expression of acidic mammalian chitinase (AMCase) is associated with Th2-driven respiratory disorders. To investigate the potentially pathological role of AMCase in allergic airway disease (AAD), we sensitized and challenged mice with ovalbumin or a combination of house dust mite (HDM) plus cockroach allergen. These mice were treated or not treated with small molecule inhibitors of AMCase, which significantly reduced allergen-induced chitinolytic activity in the airways, but exerted no apparent effect on pulmonary inflammation per se.

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Unlabelled: Natural killer (NK) cells are equipped to innately produce the cytokine gamma interferon (IFN-γ) in part because they basally express high levels of the signal transducer and activator of transcription 4 (STAT4). Type 1 interferons (IFNs) have the potential to activate STAT4 and promote IFN-γ expression, but concurrent induction of elevated STAT1 negatively regulates access to the pathway. As a consequence, it has been difficult to detect type 1 IFN stimulation of NK cell IFN-γ during viral infections in the presence of STAT1 and to understand the evolutionary advantage for maintaining the pathway.

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Operation of a heavy ion beam probe (HIBP) on a reversed field pinch is unique from other toroidal applications because the magnetic field is more temporal and largely produced by plasma current. Improved confinement, produced through the transient application of a poloidal electric field which leads to a reduction of dynamo activity, exhibits gradual changes in equilibrium plasma quantities. A consequence of this is sweeping of the HIBP trajectories by the dynamic magnetic field, resulting in motion of the sample volume.

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The unit covers Variable Numbers of Tandem Repeats (VNTR) based paternity analysis as well as the newer methods relying on PCR to analyze sequence-specific polymorphisms and microsatellite regions. The discussion of data analysis and probability calculations has been expanded to address a number of special circumstances, such as the lack of sample from an alleged father, motherless cases, and more.

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A magnetic field mapping technique via heavy ion beam trajectory imaging is being developed on the Madison Symmetric Torus reversed field pinch. This paper describes the computational tools created to model camera images of the light emitted from a simulated ion beam, reconstruct a three-dimensional trajectory, and estimate the accuracy of the reconstruction. First, a computer model is used to create images of the torus interior from any candidate camera location.

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