1,239 research outputs found
Meteoroid impact flash analyzer Final report
Micrometeoroid mass, velocity, and composition from impact flash signature by spectroscopic analysi
On the smallest scale for the incompressible Navier-Stokes equations
It is proven that for solutions to the two- and three-dimensional incompressible Navier-Stokes equations the minimum scale is inversely proportional to the square root of the Reynolds number based on the kinematic viscosity and the maximum of the velocity gradients. The bounds on the velocity gradients can be obtained for two-dimensional flows, but have to be assumed to be three-dimensional. Numerical results in two dimensions are given which illustrate and substantiate the features of the proof. Implications of the minimum scale result to the decay rate of the energy spectrum are discussed
Computer and internet interventions to optimize listening and learning for people with hearing loss: accessibility, use, and adherence
Purpose: The aim of this research forum article was to examine accessibility, use, and adherence to computerized and online interventions for people with hearing loss. Method: Four intervention studies of people with hearing loss were examined: 2 auditory training studies, 1 working memory training study, and 1 study of multimedia educational support.
Results: A small proportion (approximately 15%) of participants had never used a computer, which may be a barrier to the accessibility of computer and Internet based interventions. Computer competence was not a factor in intervention use or adherence. Computer skills and Internet access influenced participant preference for the delivery method of the multimedia educational support program.
Conclusions: It is important to be aware of current barriers to computer and Internet-delivered interventions for people with hearing loss. However, there is a clear need to develop and future-proof hearing-related applications for online delivery
Un comentario al texto Coneixences de les monedes de los Memoriales de Pere Miquel Carbonell
Published studies assessing the association between cognitive performance and speech-in-noise perception examine different aspects of each, test different listeners, and often report quite variable associations. By examining the published evidence base using a systematic approach, we aim to identify robust patterns across studies and highlight any remaining gaps in knowledge. We limit our assessment to adult non-hearing aid users with audiometric profiles ranging from normal hearing to moderate hearing loss. A total of 253 articles were independently assessed by two researchers, with 25 meeting the criteria for inclusion. Included articles assessed cognitive measures of attention, memory, executive function, IQ and processing speed. Speech-in-noise measures varied by target (phonemes/syllables, words, sentences) and masker type (unmodulated noise, modulated noise, multi (n>2) talker babble, and n<2 talker babble). The overall association between cognitive performance and speech-in-noise perception was r=0.31. For component cognitive domains, the association with (pooled) speech-in-noise perception were; processing speed (r=0.39), inhibitory control (r=0.34), working memory (r=0.28), episodic memory (r=0.26) and crystalized IQ (r=0.18). Similar associations were shown for the different speech target and masker types. This review suggests a general association of r≈0.3 between cognitive performance and speech perception, although some variability in association appeared to exist depending on cognitive domain and speech-in-noise target or masker assessed. Where assessed, degree of unaided hearing loss did not play a major moderating role. We identify a number of cognitive performance and speech-in-noise perception combinations that have not been tested, and whose future investigation would enable further finer-grained analyses of these relationships
Darier-White Disease with Sensorineural Hearing Loss – A Case Report
Darier-White disease (keratosis follicularis) is a rare autosomal dominant genodermatosis characterized by hyperkeratotic papules and plaques in seborrheic areas, often presenting with nail abnormalities and occasionally mucous membrane changes.It has been associated with neurocognitive/psychiatric disorders, ankylosing spondylitis, hidradenitis suppurativa and nephritis. Affected individuals also have an increased tendency to cutaneous infections.
However, a thorough literature search showed no association with sensorineural hearing loss. We herein report the case of a 34-year-old Nigerian man with disfiguring Darier-White disease (DWD) associated with spondyloarthropathy and sensorineural hearing loss. We affirm that early diagnosis, prompt and appropriate therapy and adequate patient education can avert undesirable outcomes
Systems of Systems Engineering Thesaurus Approach: From Concept to Realisation
The developing discipline of Systems of Systems Engineering (SoSE) is gaining attention in an increasingly broad range of domains; however, each domain comes with its own set of terms and concepts so that there may be confusion between different domains ostensibly engaged in similar challenges. SoSE is faced with concept multiplicity (one term, more than one concept) and term multiplicity (one concept, more than one term). It is unrealistic to expect long-established domains to simply change ontology to match with other domains, but a means of recognising related concepts and terms across domains and across industrial sectors will enable more rapid progress to be made in the development of SoSE. The approach taken to generating a thesaurus, through which such relationships can be documented, is presented. The approach is essentially consultative among SoSE experts and the current version of the thesaurus is available online. A combination of problem statement definition and logical decomposition has been used; the method is described and application is illustrated using well-known terms
GAUSSPY+: A fully automated Gaussian decomposition package for emission line spectra
Our understanding of the dynamics of the interstellar medium is informed by the study of the detailed velocity structure of emission line observations. One approach to study the velocity structure is to decompose the spectra into individual velocity components; this leads to a description of the data set that is significantly reduced in complexity. However, this decomposition requires full automation lest it become prohibitive for large data sets, such as Galactic plane surveys. We developed GAUSSPY+, a fully automated Gaussian decomposition package that can be applied to emission line data sets, especially large surveys of HI and isotopologues of CO. We built our package upon the existing GAUSSPY algorithm and significantly improved its performance for noisy data. New functionalities of GAUSSPY+ include: (i) automated preparatory steps, such as an accurate noise estimation, which can also be used as stand-alone applications; (ii) an improved fitting routine; (iii) an automated spatial refitting routine that can add spatial coherence to the decomposition results by refitting spectra based on neighbouring fit solutions. We thoroughly tested the performance of GAUSSPY+ on synthetic spectra and a test field from the Galactic Ring Survey. We found that GAUSSPY+ can deal with cases of complex emission and even low to moderate signal-to-noise values
Meshfree finite differences for vector Poisson and pressure Poisson equations with electric boundary conditions
We demonstrate how meshfree finite difference methods can be applied to solve
vector Poisson problems with electric boundary conditions. In these, the
tangential velocity and the incompressibility of the vector field are
prescribed at the boundary. Even on irregular domains with only convex corners,
canonical nodal-based finite elements may converge to the wrong solution due to
a version of the Babuska paradox. In turn, straightforward meshfree finite
differences converge to the true solution, and even high-order accuracy can be
achieved in a simple fashion. The methodology is then extended to a specific
pressure Poisson equation reformulation of the Navier-Stokes equations that
possesses the same type of boundary conditions. The resulting numerical
approach is second order accurate and allows for a simple switching between an
explicit and implicit treatment of the viscosity terms.Comment: 19 pages, 7 figure
Differential Gene Expression and Protein Abundance Evince Ontogenetic Bias toward Castes in a Primitively Eusocial Wasp
Polistes paper wasps are models for understanding conditions that may have characterized the origin of worker and queen castes and, therefore, the origin of paper wasp sociality. Polistes is “primitively eusocial” by virtue of having context-dependent caste determination and no morphological differences between castes. Even so, Polistes colonies have a temporal pattern in which most female larvae reared by the foundress become workers, and most reared by workers become future-reproductive gynes. This pattern is hypothesized to reflect development onto two pathways, which may utilize mechanisms that regulate diapause in other insects. Using expressed sequence tags (ESTs) for Polistes metricus we selected candidate genes differentially expressed in other insects in three categories: 1) diapause vs. non-diapause phenotypes and/or worker vs. queen differentiation, 2) behavioral subcastes of worker honey bees, and 3) no a priori expectation of a role in worker/gyne development. We also used a non-targeted proteomics screen to test for peptide/protein abundance differences that could reflect larval developmental divergence. We found that foundress-reared larvae (putative worker-destined) and worker-reared larvae (putative gyne-destined) differed in quantitative expression of sixteen genes, twelve of which were associated with caste and/or diapause in other insects, and they also differed in abundance of nine peptides/proteins. Some differentially-expressed genes are involved in diapause regulation in other insects, and other differentially-expressed genes and proteins are involved in the insulin signaling pathway, nutrient metabolism, and caste determination in highly social bees. Differential expression of a gene and a peptide encoding hexameric storage proteins is especially noteworthy. Although not conclusive, our results support hypotheses of 1) larval developmental pathway divergence that can lead to caste bias in adults and 2) nutritional differences as the foundation of the pathway divergence. Finally, the differential expression in Polistes larvae of genes and proteins also differentially expressed during queen vs. worker caste development in honey bees may indicate that regulatory mechanisms of caste outcomes share similarities between primitively eusocial and advanced eusocial Hymenoptera
Spin readout via spin-to-charge conversion in bulk diamond nitrogen-vacancy ensembles
We demonstrate the optical readout of ensembles of nitrogen-vacancy (NV) center spins in a bulk diamond sample via spin-to-charge conversion. A high power 594 nm laser is utilized to selectively ionize these paramagnetic defects in the mS=0 spin state with a contrast of up to 12%. In comparison to the conventional 520 nm spin readout, the spin-to-charge-conversion-based readout provides a higher signal-to-noise ratio, with tenfold sensing measurement speedup for millisecond long pulse sequences. This level of performance was achieved for an NV− ionization of only 25%, limited by the ionization and readout laser powers. These observations pave the way to a range of high-sensitivity metrology applications where the use of NV− ensembles in bulk diamond has proven useful, including sensing and imaging of target materials overlaid on the diamond surface
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