301 research outputs found
Effects of cochlear implantation on binaural hearing in adults with unilateral hearing loss
A FDA clinical trial was carried out to evaluate the potential benefit of cochlear implant (CI) use for adults with unilateral moderate-to-profound sensorineural hearing loss. Subjects were 20 adults with moderate-to-profound unilateral sensorineural hearing loss and normal or near-normal hearing on the other side. A MED-EL standard electrode was implanted in the impaired ear. Outcome measures included: (a) sound localization on the horizontal plane (11 positions, −90° to 90°), (b) word recognition in quiet with the CI alone, and (c) masked sentence recognition with the target at 0° and the masker at −90°, 0°, or 90°. This battery was completed preoperatively and at 1, 3, 6, 9, and 12 months after CI activation. Normative data were also collected for 20 age-matched control subjects with normal or near-normal hearing bilaterally. The CI improved localization accuracy and reduced side bias. Word recognition with the CI alone was similar to performance of traditional CI recipients. The CI improved masked sentence recognition when the masker was presented from the front or from the side of normal or near-normal hearing. The binaural benefits observed with the CI increased between the 1- and 3-month intervals but appeared stable thereafter. In contrast to previous reports on localization and speech perception in patients with unilateral sensorineural hearing loss, CI benefits were consistently observed across individual subjects, and performance was at asymptote by the 3-month test interval. Cochlear implant settings, consistent CI use, and short duration of deafness could play a role in this result
Design and Synthesis of a Novel Alpha-Methylene Lactone Chemotherapeutic Agent
Goniothalamin, a natural product isolated from the dried stem bark of Malaysian plants of the genus Goniothalamus, has been shown to induce apoptosis in cancer cells. The bioactivity of this molecule is though to be due to its ability to react with thiols. One mechanism involves its reaction with glutathione, a natural antioxidant found in all cells. Using a four step synthetic sequence, a novel gamma-lactone analogue of goniothalamin has been prepared that replaces the endocylic double bond in goniothalamin\u27s lactone core with an exocyclic double bond. It is anticipated that this alteration will allow the compound to react more rapidly with thiols and therefore increase its cytotoxicity towards cancer cells
Festschrift Symposium: Honoring Professor Samuel Pillsbury
The Loyola of Los Angeles Law Review is pleased to publish this Festschrift Symposium Honoring Professor Samuel Pillsbury. The following is an edited transcript of the live symposium held at LMU Loyola Law School on Friday, March 25, 2022
Active optical system for spaceborne telescopes Final report
Active optical system for spaceborne, orbiting telescope
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Analysis of Abrupt Transitions in Ecological Systems
The occurrence and causes of abrupt transitions, thresholds, or regime shifts between ecosystem states are of great concern and the likelihood of such transitions is increasing for many ecological systems. General understanding of abrupt transitions has been advanced by theory, but hindered by the lack of a common, accessible, and data-driven approach to characterizing them. We apply such an approach to 30–60 years of data on environmental drivers, biological responses, and associated evidence from pelagic ocean, coastal benthic, polar marine, and semi-arid grassland ecosystems. Our analyses revealed one case in which the response (krill abundance) linearly tracked abrupt changes in the driver (Pacific Decadal Oscillation), but abrupt transitions detected in the three other cases (sea cucumber abundance, penguin abundance, and black grama grass production) exhibited hysteretic relationships with drivers (wave intensity, sea-ice duration, and amounts of monsoonal rainfall, respectively) through a variety of response mechanisms. The use of a common approach across these case studies illustrates that: the utility of leading indicators is often limited and can depend on the abruptness of a transition relative to the lifespan of responsive organisms and observation intervals; information on spatiotemporal context is useful for comparing transitions; and ancillary information from associated experiments and observations aids interpretation of response-driver relationships. The understanding of abrupt transitions offered by this approach provides information that can be used to manage state changes and underscores the utility of long-term observations in multiple sentinel sites across a variety of ecosystems.Organismic and Evolutionary Biolog
The Compound Action Potential in Subjects Receiving a Cochlear Implant
The compound action potential (CAP) is a purely neural component of the cochlea’s response to sound, and may provide information about the existing neural substrate in cochlear implant (CI) subjects that can help account for variance in speech perception outcomes
Construction of Precision sMDT Detector for ATLAS Muon Spectrometer Upgrade
This paper describes the small-diameter monitored drift-tube detector
construction at the University of Michigan as a contribution to the ATLAS Muon
Spectrometer upgrade for the high-luminosity Large Hadron Collider at CERN.
Measurements of the first 30 chambers built at Michigan show that the drift
tube wire position accuracy meets the specification of 20 microns. The
positions of the platforms for alignment and magnetic field sensors are all
installed well within the required precision. The cosmic ray test measurements
show single wire tracking resolution of 100 +- 7 microns with an average
detection efficiency above 99 %. The infrastructure, tooling, techniques, and
procedures for chamber production are described in detail. The results from the
chamber quality control tests of the first 30 constructed chambers are
reported.Comment: 35 pages, 41 figure
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A compilation of observation[s] from moored current meters, thermographs, and wind instrument. Vol. 4. Peru continental shelf March-April 1969
A summary of moored instrument measurements over the continental
shelf of Peru is presented. Measurements of variables were made in an
upwelling zone between Pisco and San Juan, from 28 March to 9 April, 1969.
Time series of temperature and horizontal current and wind velocities were
obtained at several depths and locations by an array of moored, recording
instruments. Supplementary hydrographic and drogue measurements were
also made
Influence of Age at Revision Cochlear Implantation on Speech Perception Outcomes
IMPORTANCE: This study reviewed whether advanced age should be a consideration when revision cochlear implantation is warranted.
OBJECTIVE: To examine whether age at revision cochlear implantation is related to postrevision speech perception performance.
DESIGN, SETTING, AND PARTICIPANTS: A retrospective analysis was performed in an academic tertiary care center. Participants included 14 younger adults (<65 years) and 15 older adults (≥65 years) who underwent revision cochlear implantation.
INTERVENTION: Revision cochlear implantation.
MAIN OUTCOMES AND MEASURES: Speech perception performance, as measured with consonant-nucleus-consonant [CNC] words in quiet, at the best prerevision interval as well as the 3- and 6-month postrevision intervals were compared between the 2 cohorts. The CNC word test consists of 10 lists of 50 phonemically balanced monosyllabic words, scored with a range of 0% to 100% correct.
RESULTS: Both cohorts experienced a restoration in speech perception scores after revision cochlear implantation compared with their best performance before the revision (mean [SD] CNC word test scores for the younger cohort: 43.9% [25.6%] before revision and 47.7% [21.3%] at 3 months and 47.6% [19.8%] at 6 months after revision; for the older cohort: 36.3% [19.1%] before revision and 35.3% [17.2%] at 3 months and 39.9% [16.3%] at 6 months after revision; F₂,₅₄= 0.93; P = .40). There was no interaction between age at revision surgery and speech perception performance at each assessment interval (F₂,₅₄= 0.51; P = .60).
CONCLUSIONS AND RELEVANCE: In this study, age at revision cochlear implantation was not related to postrevision speech perception performance. Advanced age should not be considered a contraindication to revision cochlear implantation
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