Ear and hearing health in Aboriginal and Torres Strait Islander people aged 15 years and older: A scoping review.

OBJECTIVE: Review empirical research investigating the prevalence, experiences and management of hearing loss and ear disease in Aboriginal and Torres Strait Islander adults. DESIGN: Scoping review. STUDY SAMPLES: Searches of four electronic databases, Advanced Google, and key webpages identified 16,373 studies - 21 met inclusion criteria: original research relating to hearing/ear health and Aboriginal and Torres Strait Islander adults. RESULTS: Fourteen studies measured prevalence of hearing loss or middle-ear dysfunction, with a rate of hearing loss at an estimated 50% (reports ranging from 8% to 100%). Five studies reported views, attitudes, and experiences of hearing loss, with results showing hearing loss negatively impacted individual experiences in health and justice systems, and health professionals had limited understanding of the socioeconomic risk factors of middle ear disease. No articles directly reported on hearing loss management. CONCLUSIONS: There is a lack of research into the hearing health of Aboriginal and Torres Strait Islander adults, despite its critical importance in addressing health and social inequities. Given the widely varying and imprecise estimated rates of hearing loss detected, urgent action is needed to obtain accurate prevalence estimates and, in partnership with Aboriginal and Torres Strait Islander communities, identify the best methods of screening and managing hearing loss.

Student perceptions of two simulated learning environments in paediatric audiology.

Objective: To determine audiology student perceptions of two simulated learning environments (SLE) in paediatric audiology.Design: A one-shot case study design.Study sample: Fifteen audiology students who completed questionnaires after participating in two SLEs, one simulating auditory brainstem response (ABR) assessments of neonates in a hospital ward and one simulating visually reinforced orientation audiometry (VROA) assessments of young children in an audiology clinic.Results: The students responded positively to 11/11 areas of audiometric testing and client interaction in both SLEs, to 7/7 aspects of their interactions with the mannequins in both SLEs, and to 8/8 aspects of their interactions with fellow students playing the role of parent in the ABR SLE and 7/8 of these aspects in the VROA SLE. The students reported low levels of anxiety towards both SLEs but rated the ABR SLE more highly than the VROA SLE in areas of preparedness, effectiveness, realism, pre-SLE training, reinforcement of lecture content, and overall usefulness.Conclusions: The participating students responded positively to almost all aspects of both SLEs. Further research is warranted using research designs capable of determining if these SLEs directly improve student abilities as they transition from academic settings to clinical placements in paediatric audiology.

NetRaVE: constructing dependency networks using sparse linear regression.

UNLABELLED: NetRaVE is a small suite of R functions for generating dependency networks using sparse regression methods. Such networks provide an alternative to interpreting 'top n lists' of genes arising out of an analysis of microarray data, and they provide a means of organizing and visualizing the resulting information in a manner that may suggest relationships between genes. AVAILABILITY: NetRaVE is freely available for academic use and has been tested in R 2.10.1 under Windows XP, Linux and Mac OS X. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Discovery of hydroxyl radio emission from infrared stars.

Radio spectral line emission from hydroxyl radicals has been detected from four infrared stars. The emission from the infrared star NML Cygni at 1612 megahertz is the strongest radio emission line yet detected. Sixteen other stars with infrared excesses showed no detectable hydroxyl radio emission.

Microwave measurement of mesospheric carbon monoxide.

Ground-based observation of atmospheric absorption of solar radiation at a wavelength of 2.6 millimeters has provided the first measurement of mesospheric carbon monoxide. The measurement agrees with photochemical predictions of a carbon monoxide source in the lower thermosphere due to dissociation of carbon dioxide by solar radiation, and has implications for the magnitude of vertical transport in the mesosphere.

Venus: microwave detection of carbon monoxide.

The 115-gigahertz microwave line of carbon monoxide has been detected in the spectrum of Venus. The measurement proves that the carbon monoxide mixing ratio increases above an altitude of 85 kilometers in the Venus stratosphere and provides quantitative information on carbon monoxide in the altitude region from 80 to 110 kilometers. This altitude region is well above that which has been previously sensed.

Mars: microwave detection of carbon monoxide.

The 115-gigahertz microwave line of carbon monoxide has been detected in the spectrum of Mars. The measurement is sensitive to carbon monoxide between the surface and an altitude of approximately 50 kilometers in the martian atmosphere. This extends the altitude region to well above that previously sensed.

Mercury: observations of the 3.4-millimeter radio emission.

Observations of the 3.4-millimeter radio emission from Mercury during 1965 and 1966 yielded the following relationship between average brightness temperature T(B) of the disk and the planetocentric phase angle i: T(B) = 277 (+/- 12) + 97 (+/- 17) cos [i + 29 deg (+/- 10 deg)] degrees K The errors are statistical standard; the phase shift corresponds to a phase lag-that is, the maximum and minimum of insolation lag the maximum and minimum of planetary radiation.

On the dual structure of the auditory brainstem response in dogs.

OBJECTIVE: To use the over-complete discrete wavelet transform (OCDWT) to further examine the dual structure of auditory brainstem response (ABR) in the dog. METHODS: ABR waveforms recorded from 20 adult dogs at supra-threshold (90 and 70dBnHL) and threshold (0-15dBSL) levels were decomposed using a six level OCDWT and reconstructed at individual scales (frequency ranges) A6 (0-391Hz), D6 (391-781Hz), and D5 (781-1563Hz). RESULTS: At supra-threshold stimulus levels, the A6 scale (0-391Hz) showed a large amplitude waveform with its prominent wave corresponding in latency with ABR waves II/III; the D6 scale (391-781Hz) showed a small amplitude waveform with its first four waves corresponding in latency to ABR waves I, II/III, V, and VI; and the D5 scale (781-1563Hz) showed a large amplitude, multiple peaked waveform with its first six waves corresponding in latency to ABR waves I, II, III, IV, V, and VI. At threshold stimulus levels (0-15dBSL), the A6 scale (0-391Hz) continued to show a relatively large amplitude waveform, but both the D6 and D5 scales (391-781 and 781-1563Hz, respectively) now showed relatively small amplitude waveforms. CONCLUSIONS: A dual structure exists within the ABR of the dog, but its relative structure changes with stimulus level. SIGNIFICANCE: The ABR in the dog differs from that in the human both in the relative contributions made by its different frequency components, and the way these components change with stimulus level.

Utilization of the Denny-Brown collection: differential recovery of forelimb and hind limb stepping after extensive unilateral cerebral lesions.

The Denny-Brown collection of primate lesion material was used to test the hypothesis that there is a difference in the rate of forelimb and hind limb recovery of locomotor movements after major unilateral cerebral ablation (pre/postcentral gyrus, decortication or hemispherectomy). The results indicate that, following major cerebral injury, hind limb recovery precedes that of the forelimb in adolescent and adult primates, but not in infants. This suggests that there is an underlying physiological basis to the widely-held belief that, in humans, lower limb recovery after stroke is generally more complete than that of the upper limb.

The relationship between the auditory brain-stem response and its reconstructed waveforms following discrete wavelet transformation.

OBJECTIVE: To examine the relationship between the auditory brain-stem response (ABR) and its reconstructed waveforms following discrete wavelet transformation (DWT), and to comment on the resulting implications for ABR DWT time-frequency analysis. METHODS: ABR waveforms were recorded from 120 normal hearing subjects at 90, 70, 50, 30, 10 and 0 dBnHL, decomposed using a 6 level discrete wavelet transformation (DWT), and reconstructed at individual wavelet scales (frequency ranges) A6, D6, D5 and D4. These waveforms were then compared for general correlations, and for patterns of change due to stimulus level, and subject age, gender and test ear. RESULTS: The reconstructed ABR DWT waveforms showed 3 primary components: a large-amplitude waveform in the low-frequency A6 scale (0-266.6 Hz) with its single peak corresponding in latency with ABR waves III and V; a mid-amplitude waveform in the mid-frequency D6 scale (266.6-533.3 Hz) with its first 5 waves corresponding in latency to ABR waves I, III, V, VI and VII; and a small-amplitude, multiple-peaked waveform in the high-frequency D5 scale (533.3-1066.6 Hz) with its first 7 waves corresponding in latency to ABR waves I, II, III, IV, V, VI and VII. Comparisons between ABR waves I, III and V and their corresponding reconstructed ABR DWT waves showed strong correlations and similar, reliable, and statistically robust changes due to stimulus level and subject age, gender and test ear groupings. Limiting these findings, however, was the unexplained absence of a small number (2%, or 117/6720) of reconstructed ABR DWT waves, despite their corresponding ABR waves being present. CONCLUSIONS: Reconstructed ABR DWT waveforms can be used as valid time-frequency representations of the normal ABR, but with some limitations. In particular, the unexplained absence of a small number of reconstructed ABR DWT waves in some subjects, probably resulting from 'shift invariance' inherent to the DWT process, needs to be addressed. SIGNIFICANCE: This is the first report of the relationship between the ABR and its reconstructed ABR DWT waveforms in a large normative sample.

On wavelet analysis of auditory evoked potentials.

OBJECTIVE: To determine a preferred wavelet transform (WT) procedure for multi-resolution analysis (MRA) of auditory evoked potentials (AEP). METHODS: A number of WT algorithms, mother wavelets, and pre-processing techniques were examined by way of critical theoretical discussion followed by experimental testing of key points using real and simulated auditory brain-stem response (ABR) waveforms. Conclusions from these examinations were then tested on a normative ABR dataset. RESULTS: The results of the various experiments are reported in detail. CONCLUSIONS: Optimal AEP WT MRA is most likely to occur when an over-sampled discrete wavelet transformation (DWT) is used, utilising a smooth (regularity >or=3) and symmetrical (linear phase) mother wavelet, and a reflection boundary extension policy. SIGNIFICANCE: This study demonstrates the practical importance of, and explains how to minimize potential artefacts due to, 4 inter-related issues relevant to AEP WT MRA, namely shift variance, phase distortion, reconstruction smoothness, and boundary artefacts.

Nucleus accumbens inhibits specific motor but not nonspecific classically conditioned responses.

A classical leg flexion conditioning paradigm was used to elicit specific motor responses, as well as nonspecific responses requiring less involvement of the motor system, in cats. Stimulating and lesioning the nucleus accumbens differentially affected these two types of responses. The specific conditioned responses, leg flexion and vocalization, were suppressed by stimulation and enhanced by lesions of the nucleus accumbens. The nonspecific responses, changes in respiration rate and amplitude, and in heart rate, were affected inconsistently or not at all. This suggests a role for the nucleus accumbens in the inhibition of motor components of learned emotional responses, and is consistent with hypotheses holding that the nucleus accumbens gates the access of the limbic system to motor systems.

Intraoperative autologous transfusion in revision total hip arthroplasty.

The records of ninety-eight patients (100 hips) who had revision total hip arthroplasty were reviewed to evaluate the efficacy of intraoperative autologous transfusion in reducing homologous blood-transfusion requirements. In the fifty hips in the study group, a mean of 685 milliliters of autologous blood, or 47 per cent of the estimated loss of blood, was transfused intraoperatively. During the entire course of hospitalization, the mean of the total homologous blood-transfusion requirements was 795 milliliters in thirty-nine study-group patients, compared with 1160 milliliters in forty-six control-group patients who did not have autologous transfusion. This difference was statistically significant (p less than 0.029). Eleven patients in the study group and four patients in the control group did not receive homologous blood. Over-all, the use of intraoperative autologous transfusion was directly responsible for a 42 per cent reduction in the total amount of homologous blood that was transfused.

Combined reconstruction of the anterior cruciate ligament in competitive athletes.

Fifty-eight professional and competitive amateur athletes had a combined reconstruction of the anterior cruciate ligament, with use of the semitendinosus tendon for the intra-articular portion of the reconstruction and a strip of iliotibial band for the extra-articular augmentation. Thirty patients (thirty-two knees) were evaluated two to seven years postoperatively to assess the results and the ability to return to athletics. Follow-up consisted of an interview, clinical and roentgenographic examinations, and testing with an arthrometer. Six patients (20 per cent) had a rating of excellent; twenty-two (73 per cent), good; and two (7 per cent), fair. There were no poor results. Of the thirty-two knees, twenty had an associated injury: twenty meniscal tears in eighteen knees, three tears of the medial collateral ligament, four osteochondral fractures of the lateral femoral condyle, and two loose bodies. Combined reconstruction of the anterior cruciate ligament resulted in improved stability of the knee in these patients whose goal of treatment was to be able to resume sports at a highly competitive level.

Antibody to hepatitis C virus increases with time on hemodialysis.

We studied whether chronic hemodialysis is associated with an increased risk of exposure to hepatitis C virus. Utilizing a first generation Elisa assay (C-100 Elisa, Ortho Diagnostic Systems, Raritan, NJ) and the Chiron RIBA HCV second generation assay (RIBA, Chiron, Emeryville, CA and Ortho Diagnostic Systems, Raritan, NJ), antibody to HCV was found in 31 of 87 hemodialysis patients (36%). Patients on hemodialysis less than 2 years had an antibody incidence of 15% (n = 46), as contrasted with a 59% incidence for patients on dialysis greater than or equal to 2 years (n = 41). We were unable to demonstrate a correlation of HCV-antibody positivity with history of blood transfusion. The overall incidence is higher than previously reported for hemodialysis patients in the United States. The very high incidence found in patients on dialysis greater than or equal to 2 years suggests that factors in the hemodialysis unit might contribute to the spread of virus.

Pharmacological manipulations of the nucleus accumbens: effects on classically conditioned responses and locomotor activity in the cat.

Agonists and antagonists of dopamine, acetylcholine, and glutamate were injected bilaterally into the nucleus accumbens in 5 adult cats, and their effects on classically conditioned responses and locomotor activity were observed. Dopamine reduced conditioned consummatory responses (leg flexion and vocalization) and conditioned changes in respiration rate, but did not affect other conditioned preparatory responses (changes in heart rate and respiration amplitude). The cholinergic agonist oxotremorine reduced both conditioned and unconditioned leg flexion. The glutamatergic agonist and antagonist had no effect on any of the conditioned responses. All drugs except haloperidol increased the cats locomotor activity in an open field setting. The results suggest that dopaminergic input to the nucleus accumbens is involved in the inhibition of consummatory conditioned responses, and that the behavioral effect of dopamine in the nucleus accumbens might be dependent on the emotional state of the animal.

Ventral tegmental area lesions differentially affect responses controlled by CS-US contiguity and response-reinforcer contingency in the rat.

Rats with electrolytic lesions of the ventral tegmental area (VTA, n = 32), or sham lesions (n = 32), were tested in four behavioral paradigms in a shuttlebox. The paradigms were designed to assess the motivational influence of CS-US contiguity and response-reinforcer contingency. The VTA lesion increased the number of shuttle responses in the paradigms involving contiguity between a warning signal and a shock, without affecting responses controlled by the contingency between shuttling and shock avoidance. Escape latency was reduced by the lesion, but the general locomotor activity of the rats was not increased.The data suggest that the VTA normally acts to inhibit behavior motivated by classically conditioned fear. The results are discussed in terms of the hypothesis that the dopaminergic projection from the VTA to the nucleus accumbens plays a role in the inhibition of emotionally motivated motor responses.

Cholinergic manipulations and passive avoidance in the rat: effects on acquisition and recall.

A review of the literature concerning cholinergic manipulations and passive avoidance reveals that state-dependency is usually not controlled adequately, nor is acquisition of the passive avoidance task ascertained before retention is tested. These problems make interpretation of results difficult. We report three experiments on 129 rats, controlling both of these factors, in which scopolamine and pilocarpine impaired both acquisition and retention of a passive avoidance response. Lesions of the nucleus basalis magnocellularis had no effect on this task. The results suggest that an optimal level of central cholinergic activity exists for learning and memory, and that deviations from this optimal level impair acquisition and retention.