4,731 research outputs found
Incorporating Over-the-Counter Hearing Aids into Private Audiology Practice
Over-the-counter (OTC) hearing aids are a new category of hearing aid devices designed to help adults with mild to moderate sensorineural hearing loss. This new category of devices was created with the aim to provide increased access to hearing aids for millions of Americans. Their advent has created significant change for hearing healthcare within the United States as they can be purchased without consulting an audiologist or medical professional. As a result of these changes, private audiology practice owners must choose how they will react. Moving forward they must decide if they will integrate OTC hearing aids into their practices, and if they do, how that integration would work for both the practice owner/audiologist and the consumer/patient. The advantages and disadvantages of incorporating OTC hearing aids into private audiology practice are discussed along with three different models of integration that could be utilized. The hybrid model is proposed as the most advantageous option. Little to no scholarly research on OTC hearing aids currently exists. As such, directions for future research and other needs are considered to better understand the impact that these devices will certainly have
Eye Movement Monitoring Reveals Differential Influences of Emotion on Memory
Research shows that memory for emotional aspects of an event may be enhanced at the cost of impaired memory for surrounding peripheral details. However, this has only been assessed directly via verbal reports which reveal the outcome of a long stream of processing but cannot shed light on how/when emotion may affect the retrieval process. In the present experiment, eye movement monitoring (EMM) was used as an indirect measure of memory as it can reveal aspects of online memory processing. For example, do emotions modulate the nature of memory representations or the speed with which such memories can be accessed? Participants viewed central negative and neutral scenes surrounded by three neutral objects and after a brief delay, memory was assessed indirectly via EMM and then directly via verbal reports. Consistent with the previous literature, emotion enhanced central and impaired peripheral memory as indexed by eye movement scanning and verbal reports. This suggests that eye movement scanning may contribute and/or is related to conscious access of memory. However, the central/peripheral tradeoff effect was not observed in an early measure of eye movement behavior, i.e., participants were faster to orient to a critical region of change in the periphery irrespective of whether it was previously studied in a negative or neutral context. These findings demonstrate emotion's differential influences on different aspects of retrieval. In particular, emotion appears to affect the detail within, and/or the evaluation of, stored memory representations, but it may not affect the initial access to those representations
Quantum rotor theory of spinor condensates in tight traps
In this work, we theoretically construct exact mappings of many-particle
bosonic systems onto quantum rotor models. In particular, we analyze the rotor
representation of spinor Bose-Einstein condensates. In a previous work it was
shown that there is an exact mapping of a spin-one condensate of fixed particle
number with quadratic Zeeman interaction onto a quantum rotor model. Since the
rotor model has an unbounded spectrum from above, it has many more eigenstates
than the original bosonic model. Here we show that for each subset of states
with fixed spin F_z, the physical rotor eigenstates are always those with
lowest energy. We classify three distinct physical limits of the rotor model:
the Rabi, Josephson, and Fock regimes. The last regime corresponds to a
fragmented condensate and is thus not captured by the Bogoliubov theory. We
next consider the semiclassical limit of the rotor problem and make connections
with the quantum wave functions through use of the Husimi distribution
function. Finally, we describe how to extend the analysis to higher-spin
systems and derive a rotor model for the spin-two condensate. Theoretical
details of the rotor mapping are also provided here.Comment: 10 pages, 2 figure
Quantum Cosmological Relational Model of Shape and Scale in 1-d
Relational particle models are useful toy models for quantum cosmology and
the problem of time in quantum general relativity. This paper shows how to
extend existing work on concrete examples of relational particle models in 1-d
to include a notion of scale. This is useful as regards forming a tight analogy
with quantum cosmology and the emergent semiclassical time and hidden time
approaches to the problem of time. This paper shows furthermore that the
correspondence between relational particle models and classical and quantum
cosmology can be strengthened using judicious choices of the mechanical
potential. This gives relational particle mechanics models with analogues of
spatial curvature, cosmological constant, dust and radiation terms. A number of
these models are then tractable at the quantum level. These models can be used
to study important issues 1) in canonical quantum gravity: the problem of time,
the semiclassical approach to it and timeless approaches to it (such as the
naive Schrodinger interpretation and records theory). 2) In quantum cosmology,
such as in the investigation of uniform states, robustness, and the qualitative
understanding of the origin of structure formation.Comment: References and some more motivation adde
Emergent Semiclassical Time in Quantum Gravity. I. Mechanical Models
Strategies intended to resolve the problem of time in quantum gravity by
means of emergent or hidden timefunctions are considered in the arena of
relational particle toy models. In situations with `heavy' and `light' degrees
of freedom, two notions of emergent semiclassical WKB time emerge; these are
furthermore equivalent to two notions of emergent classical
`Leibniz--Mach--Barbour' time. I futhermore study the semiclassical approach,
in a geometric phase formalism, extended to include linear constraints, and
with particular care to make explicit those approximations and assumptions
used. I propose a new iterative scheme for this in the cosmologically-motivated
case with one heavy degree of freedom. I find that the usual semiclassical
quantum cosmology emergence of time comes hand in hand with the emergence of
other qualitatively significant terms, including back-reactions on the heavy
subsystem and second time derivatives. I illustrate my analysis by taking it
further for relational particle models with linearly-coupled harmonic
oscillator potentials. As these examples are exactly soluble by means outside
the semiclassical approach, they are additionally useful for testing the
justifiability of some of the approximations and assumptions habitually made in
the semiclassical approach to quantum cosmology. Finally, I contrast the
emergent semiclassical timefunction with its hidden dilational Euler time
counterpart.Comment: References Update
A simultaneous search for prompt radio emission associated with the short GRB 170112A using the all-sky imaging capability of the OVRO-LWA
We have conducted the most sensitive low frequency (below 100 MHz) search to
date for prompt, low-frequency radio emission associated with short-duration
gamma-ray bursts (GRBs), using the Owens Valley Radio Observatory Long
Wavelength Array (OVRO-LWA). The OVRO-LWA's nearly full-hemisphere
field-of-view (, square degrees) allows us to search for
low-frequency (sub- MHz) counterparts for a large sample of the subset of
GRB events for which prompt radio emission has been predicted. Following the
detection of short GRB 170112A by Swift, we used all-sky OVRO-LWA images
spanning one hour prior to and two hours following the GRB event to search for
a transient source coincident with the position of GRB 170112A. We detect no
transient source, with our most constraining flux density limit of
for frequencies spanning . We
place constraints on a number of models predicting prompt, low-frequency radio
emission accompanying short GRBs and their potential binary neutron star merger
progenitors, and place an upper limit of on the fraction of energy released in the prompt radio
emission. These observations serve as a pilot effort for a program targeting a
wider sample of both short and long GRBs with the OVRO-LWA, including bursts
with confirmed redshift measurements which are critical to placing the most
constraining limits on prompt radio emission models, as well as a program for
the follow-up of gravitational wave compact binary coalescence events detected
by advanced LIGO and Virgo.Comment: 14 pages, 5 figures, ApJ submitte
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Making Change: Diffusion of Technological, Relational, and Cultural Innovation in the Newsroom
Diffusion of innovations theory typically has been applied to the spread of a particular technology or practice rather than the interplay of a cluster of innovations. This case study of a news company undergoing significant change seeks to offer a deeper understanding of multifaceted industry upheaval by considering the diffusion of three interdependent yet distinct changes. Findings suggest technological change faces the fewest hurdles, as journalists recognize the need to adapt their practices to newer capabilities. Changes to audience relationships face greater resistance, while responses to changes to the professional culture of journalism remain the most tepid
Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence
Bis-(3 ',5 ') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K-d similar to 2 mu M). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence
Geodesic motions versus hydrodynamic flows in a gravitating perfect fluid: Dynamical equivalence and consequences
Stimulated by the methods applied for the observational determination of
masses in the central regions of the AGNs, we examine the conditions under
which, in the interior of a gravitating perfect fluid source, the geodesic
motions and the general relativistic hydrodynamic flows are dynamically
equivalent to each other. Dynamical equivalence rests on the functional
similarity between the corresponding (covariantly expressed) differential
equations of motion and is obtained by conformal transformations. In this case,
the spaces of the solutions of these two kinds of motion are isomorphic. In
other words, given a solution to the problem "hydrodynamic flow in a perfect
fluid", one can always construct a solution formally equivalent to the problem
"geodesic motion of a fluid element" and vice versa. Accordingly, we show that,
the observationally determined nuclear mass of the AGNs is being overestimated
with respect to the real, physical one. We evaluate the corresponding
mass-excess and show that it is not always negligible with respect to the mass
ofthe central dark object, while, under circumstances, can be even larger than
the rest-mass of the circumnuclear gas involved.Comment: LaTeX file, 22 page
Phylogeny of the Sepia pharaonis species complex (Cephalopoda: Sepiida) based on analyses of mitochondrial and nuclear DNA sequence data
The pharaoh cuttlefish, Sepia pharaonis Ehrenberg, 1831, is a commercially fished species found from
Japan to East Africa. Previous morphological and genetic work (the latter based on the 16S rRNA
mitochondrial gene) suggested that S. pharaonis is a species complex, but relationships within the
complex remained unresolved. To clarify these relationships, we have sequenced an additional mitochondrial
gene region (cytochrome oxidase subunit I) and a nuclear gene region (rhodopsin) from
over 50 specimens from throughout the range of S. pharaonis. We have also added sequence data from
two specimens of Sepia ramani Neethiselvan, 2001, collected in southeastern India. Sepia ramani is a
species that is morphologically very similar to S. pharaonis, and there is some question regarding its
status as a distinct species. Phylogenetic analyses of a dataset comprising all three-gene regions
revealed a monophyletic S. pharaonis complex consisting of a western Indian Ocean clade, a northeastern
Australia clade, a Persian Gulf/Arabian Sea (‘Iranian’) clade, a western Pacific clade and a
central Indian Ocean clade. Relationships among these clades remain somewhat poorly supported
except for a clade comprising the Iranian clade, the western Pacific clade and the central Indian
Ocean clade. One S. pharaonis specimen was collected in the Arabian Sea, but was found to be a
member of the western Indian Ocean clade, suggesting that gene flow between these regions has
either occurred recently or is ongoing. Both specimens of S. ramani are members of the S. pharaonis
complex, but their mtDNA haplotypes are not closely related – one is a member of the central
Indian Ocean clade, while the other is rather distantly related to the northeastern Australia clade.
We suggest that ‘S. pharaonis’ may consist of several species, but morphological work is needed to
clarify species-level taxonomy within this complex
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