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The ActiPed (FitLinxx) is a uniaxial accelerometer, which objectively measures physical activity, uploads the data wirelessly to a website, allowing participants and researchers to view activity levels remotely. The aim was to validate ActiPed's step count, distance travelled and activity time against direct observation. Further, to compare against pedometer (YAMAX), accelerometer (ActiGraph) and manufacturer's guidelines. 22 participants, aged 28±7 years, undertook 4 protocols, including walking on different surfaces and incremental running protocol (from 2 mph to 8 mph). Bland-Altman plots allowed comparison of direct observation against ActiPed estimates. For step count, the ActiPed showed a low % bias in all protocols: walking on a treadmill (-1.30%), incremental treadmill protocol (-1.98%), walking over grass (-1.67%), and walking over concrete (-0.93%). When differentiating between walking and running step count the ActiPed showed a % bias of 4.10% and -6.30%, respectively. The ActiPed showed >95% accuracy for distance and duration estimations overall, although underestimated distance (p<0.01) for walking over grass and concrete. Overall, the ActiPed showed acceptable levels of accuracy comparable to previous validated pedometers and accelerometers. The accuracy combined with the simple and informative remote gathering of data, suggests that the ActiPed could be a useful tool in objective physical activity monitoring.

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Previously studies have shown that nature improves mood and self-esteem and reduces blood pressure. Walking within a natural environment has been suggested to alter autonomic nervous system control, but the mechanisms are not fully understood. Heart rate variability (HRV) is a non-invasive method of assessing autonomic control and can give an insight into vagal modulation. Our hypothesis was that viewing nature alone within a controlled laboratory environment would induce higher levels of HRV as compared to built scenes. Heart rate (HR) and blood pressure (BP) were measured during viewing different scenes in a controlled environment. HRV was used to investigate alterations in autonomic activity, specifically parasympathetic activity. Each participant lay in the semi-supine position in a laboratory while we recorded 5 min (n = 29) of ECG, BP and respiration as they viewed two collections of slides (one containing nature views and the other built scenes). During viewing of nature, markers of parasympathetic activity were increased in both studies. Root mean squared of successive differences increased 4.2 ± 7.7 ms (t = 2.9, p = 0.008) and natural logarithm of high frequency increased 0.19 ± 0.36 ms(2) Hz(-1) (t = 2.9, p = 0.007) as compared to built scenes. Mean HR and BP were not significantly altered. This study provides evidence that autonomic control of the heart is altered by the simple act of just viewing natural scenes with an increase in vagal activity.

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Postmortem examination may be useful in establishing the cause of sudden unexpected death. In many instances, however, limitations of staffing, budget, and time may force the pathologist to triage cases to external examination rather than autopsy. A rapid assay for cardiac troponin T (cTnT) to document suspected cardiac-related deaths may optimize the use of the time and resources of the autopsy pathologist. Peripheral blood was sampled percutaneously before each of 40 autopsies and placed in the well of the Cardiac T Rapid Assay unit in accordance with the included instructions, and the results were read after 15 minutes. The assay result, decedent age, postmortem interval, and evidence of cardiopulmonary resuscitation were tabulated and subsequently correlated with the cause of death. On final sign-out of each of the autopsies, the cause of death was determined to be cardiac-related (n = 20) versus the cause in non-cardiac control subjects (n = 20). This determination was made while the investigators were blinded to the cTnT assay result. Of the 20 cardiac deaths, 17 (85%) showed positive results for cTnT compared with 6 (30%) false-positive results among the 20 control cases; this result was statistically significant according to the chi-square test. In the over-50 age group, the sensitivity of this assay in detecting cardiac-related death was 91%, with a specificity of 86%. Perimortem cardiopulmonary resuscitation did not appear to result in false-positive results. In the appropriate setting, this rapid assay for cTnT can provide valuable data supportive of a cardiac-related death. This inexpensive test may best be used in triaging sudden deaths in persons over 50 to external examination versus complete autopsy.

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The managed care movement emphasizes the rationalization of health care delivery through fixed price or capitation of service and the utilization of a preferred physician or health gatekeeper. These features are advanced as measures of cost control in health care delivery. This approach presents the aging network, established under the Older Americans Act, with a number of daunting challenges which are particularly acute to service providers in rural areas. How this network responds will determine its future efficacy in the delivery of health and long-term care services. This article examines these concerns among eight rurally based senior centers and two Area Agencies on Aging in Southern West Virginia. Issues of management capacity, present and future positioning, and receptivity to managed care are emphasized. These providers stand on the strengths of a long tradition of serving clients, knowledge of their needs and face-to-face interactions with them--capabilities managed care organizations do not have. However, little outreach to managed care in these areas has occurred.

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Distortion product otoacoustic emission (DPOAE) measurements are becoming popular in the clinical realm because they have been shown to reflect cochlear function. The primary tones used to evoke the DPOAE are important in determining the amplitude of the emission recorded in the ear canal. This study examined the ratio of the primaries necessary to determine the maximum amplitude emission as a function of development, stimulus level and frequency. Optimum f(2)/f(1) ratios were measured utilizing the f(1)-sweep technique from 105 neonates between 30-42 weeks conceptional age (CA) and 40 adults. No significant difference for optimum ratio was shown between the neonatal and the adult groups. Primary tone frequency had a significant effect on optimum ratio for both neonates and adults. Low f(2) frequencies (<4 kHz) were associated with higher optimum ratios than high f(2) frequencies (>4 kHz). The adult group was used to investigate the effect of stimulus level on the optimum f(2)/f(1) ratio for f(2) frequencies from 1.7 to 10 kHz. Regression analysis showed significant differences across levels of the primaries at all frequencies except for f(2)=3.4 and 7.0 kHz. These differences in f(2)/f(1) ratio across stimulus frequency and level may be attributed to the change in the shape of the excitation profiles along the basilar membrane.

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This study examined gender differences in f(1)- and f(2)-sweep distortion product otoacoustic emission (DPOAE) phase delay measures in 60 normal-hearing human adults. Phase delay measures were obtained at six different f(2) frequencies ranging from 1.1 to 6.0 kHz (f(2)/f(1) ratios were 1.1-1.3). Primary levels for f(2) were 45 and 50 dB SPL (f(1)f(2)). Gender differences have been observed in normal-hearing human adults in both auditory brainstem response (ABR) and f(1)-sweep DPOAE studies. Gender differences in delay have been attributed to differences in the average length of the cochlea, where female cochleas are 13% shorter than male cochleas. Previously, the authors have proposed that the f(1)-sweep phase delay estimate is predominantly composed of a level-independent transport time to the site of DPOAE generation and a small proportion of the level and frequency-dependent filter build-up time. The f(2)-sweep delay also contains the transport time, however, it is predominantly composed of the filter build-up time. Therefore, delay differences between stimulation paradigms are equal to a proportion of the filter build-up time. In this study, mean f(1)- and f(2)-sweep delays were significantly longer in male ears than female ears at 1.1 kHz (45 and 50 dB). At 50 dB, f(1)-sweep phase delay measures were 18% longer in male ears (6.5 ms) than female ears (5.5 ms). Mean f(2)-sweep delays were 23% longer in male ears (10.0 ms) than female ears (8.1 ms). This gender difference was not observed when the isolated filter build-up time was calculated from the DPOAE phase delay difference. These observations may therefore be attributed to a gender-related anatomical difference in cochlear length.

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Pathologists frequently examine victims of sudden cardiac death. In some cases, a firm diagnosis of cardiac-related death can be made based on conclusive gross and histologic findings. In many other cases, we find evidence supportive of, but not diagnostic of, cardiac death (e.g., atherosclerotic coronary artery disease, cardiomegaly, myocardial scarring). A final cohort consists of cases of sudden death with minimal to mild cardiac disease, no other significant pathology, and negative toxicologic studies. This prospective study compared 38 cardiac-related deaths with 52 control cases with respect to concentrations of pericardial cardiac troponin I (cTnI), heart weight, evidence of old and/or recent myocardial injury, and presence of significant coronary artery disease. The influence of documented chest trauma and/or perimortem cardiopulmonary resuscitation (CPR) on levels of cTnI was also analyzed. Even though median cTnI levels were significantly higher in cardiac deaths than in controls (p = .003), cTnI was not found to be a significant predictor of cardiac deaths, as determined by discriminant analysis (p = .52). Heart weight >500 g, evidence of old and recent myocardial injury, and significant coronary artery disease were seen statistically more often in cardiac deaths than in controls (p < or = .005 in each case), and median age was significantly higher in cardiac deaths than in controls (p = .001). Based on a stepwise logistic regression model, significant coronary artery disease, old and recent myocardial injury, and heart weight >500 g were found to contribute significantly to the prediction of cardiac death. Finally, neither chest injury nor CPR significantly affected concentrations of cTnI in pericardial fluid. These data confirm that the presence of acute and remote myocardial injury, significant coronary artery disease, and cardiomegaly (heart weight >500 g) strongly supports the diagnosis of a cardiac-related death. In contrast to a recently published report, we do not find that elevated concentrations of cTnI in pericardial fluid are strong indicators of cardiac-related deaths using our methodology.

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This study examined cochlear filter response properties derived from f1- and f2-sweep phase delay difference measures in 60 normal hearing human adults. Seven different f2 frequencies ranging from 1.1 to 9.2 kHz were presented (f2/f1 ratios of 1.1-1.3). F2 intensity level was varied in 5 dB steps from 30 to 50 dB SPL (the level of f1 was 15 dB above the level of f2). DPOAE delay estimates in a f2-sweep paradigm are longer than in a f1-sweep paradigm at the same frequency and intensity. This indicates that the f2-sweep DPOAE phase delay is composed of a greater proportion of the filter response time at the site of DPOAE generation than the f1-sweep delay. This proportion was isolated by subtracting f1-sweep DPOAE delays from f2-sweep delays at similar f2 frequencies and intensities. Under the assumption of linearity and minimum phase the impulse response of the filter at each f2 stimulus level was calculated from the mean phase delay difference. Frequency response properties were calculated by Fourier transformation of the impulse response at each f2 frequency and intensity. High frequency low intensity impulse responses had longer response times and narrower frequency bandwidths than low frequency high intensity responses. The Q10dB values of DPOAE derived tuning curves ranged from 2.4 (1.5 kHz) to 7.3 (8.5 kHz).

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Phase measurements of distortion product otoacoustic emissions (DPOAE) provide an estimate of round-trip travel times in the cochlea. This study examined differences in f1- and f2-sweep round-trip delays estimated from DPOAE phase responses in 20 normal-hearing adult human subjects as a function of f2 frequency and sound intensity. Eight different f2 frequencies ranging from 1.1-13 kHz were presented. For both the f1- and the f2-sweep stimulation conditions the f2/f1 ratios were between 1.1 and 1.3. Primary intensity levels for f2 were varied in 5-dB steps from 30-50 dB SPL (where f1 was 15 dB > f2). Delays in the f2-sweep condition were equal to or longer than travel times in the f1-sweep condition. Round-trip delays showed a significant intensity dependence in both the f1- and f2-sweep conditions (p < or = 0.01). In both conditions, the delay increased as stimulus intensity decreased. Delay estimates in the f2-sweep condition were more strongly intensity dependent than estimates in the f1-sweep condition at f2 frequencies above 1.6 kHz. The mean difference in f2- and f1-sweep delays at low intensities ranged from 15.9 periods at the 9.2 kHz f2 place, to 2.5 periods at the 1.6 kHz f2 place. The intensity dependence of round-trip delay estimates in both conditions may be attributed to intensity-dependent changes in the cochlear filter response time related to the sharpness of tuning of DPOAE responses. The steeper intensity dependence and longer delays observed in the f2-sweep condition may similarly be attributed to a greater proportion of the f2-sweep response being composed of the filter response time.

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Managed care which emphasizes the rationalization of the way health care is financed, the devolution movement which shifts greater program responsibility to the state and local levels, and the restructuring of Medicaid along the lines of a block grant program, are issues presenting providers of aging services with a daunting set of challenges and opportunities. Providers of aging services will need to build on existing strengths, while developing new strategies, to succeed under an environment of managed care and state and local funding control.

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OBJECTIVE: To determine whether the source of age-dependent latency changes for ABR wave I results from cochlear mechanics or the haircell-neuron synapse. DESIGN: Cochlear traveling wave delays were estimated on the basis of derived ABR response latencies and DPOAE phase delays. The difference in travel time between adjacent one octave-separated frequencies was calculated for four age groups: 30 to 33 wk old, 34 to 37 wk old, 38 to 42 wk old (term), and young adults. RESULTS: We found that there were essentially no travel time differences between newborns in the 34 to 37 and the 38 to 42 wk conceptional age (CA) groups as estimated from DPOAE phase delays. For the 30- to 33-wk-olds, DPOAE travel times were increased at all frequencies, likely due to mild (about 10 to 15 dB) conductive hearing losses. Differences in travel times between adjacent bands, however, were not different from the other neonatal groups. Estimates on basis of wave I latency showed delays for the high-frequency region, 6 to 11 kHz, that were still immature at term. CONCLUSIONS: A comparison of frequency-dependent travel times calculated for wave I and DPOAE data in comparable age groups suggests mature cochlear functioning at 35 wk CA and a delayed maturation for the haircell-auditory nerve synapses relative to the preneural components for the basal turn with center frequencies above 6 kHz.

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Airbags have become an increasingly accepted automobile safety feature that can reduce the morbidity and mortality associated with motor vehicle collisions. We present the following case report of an unusual fatality with multiple internal injuries from a minor mechanism motor vehicle collision. The cause of injuries was determined to be secondary to the deployment of a driver's side airbag without the concomitant use of a lap-shoulder belt.

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Neurological manifestations of HIV disease occur in most adults and children with AIDS. Many of those affected will inevitably suffer clinical neurological deficits involving mental function, movement, and sensation. Surprisingly, there are not as yet adequate monitoring systems to predict the onset and/or progression of HIV infection of the CNS. Neurological, neuropsychological, CSF, and magnetic resonance imaging (MRI) analyses cannot accurately detect mental deterioration during advancing HIV disease. Reports suggest that in vivo proton MR spectroscopy (1H MRS) of the brain could be a predictor of virus-induced neurological deterioration. H MRS can measure N-acetylaspartate (NAA), a metabolite present only in neurons. Decreased NAA reflects neuronal loss seen during HIV infection of brain. To uncover possible associations between NAA levels and HIV-induced neurological disease we performed serial 1H MRS brain tests in HIV-infected patients with or at risk for encephalopathy. Serial testing, for 1 year, of 10 patients showed that brain NAA levels decreased in all HIV-infected subjects. The most severe NAA reductions were associated with progressive neurological impairment. These findings suggest that NAA can be used as a noninvasive measure of neuronal loss in patients with HIV disease. Most important, the results suggest that 1H MRS could be used to monitor therapeutics directed against HIV infection within the CNS.

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Distortion product emission (DPE) growth functions, demographic data, and pure tone thresholds were recorded in 229 normal-hearing and hearing-impaired ears. Half of the data set (115 ears) was used by a discriminant analysis routine to classify DPE and demographic features into either a normal pure tone threshold (PTT) group or an impaired PTT group (PTT greater than 30 dB SPL) at six frequencies in the audiometric range. The six discriminant functions developed from this classification process were then used to predict pure tone threshold group membership in the remaining 114-ear data set. Frequency-specific prediction accuracy varied from 71% (correct classification of hearing impairment at 1025 Hz) to 92% (correct classification of normal hearing at 2050 Hz). Of the 45 DPE and demographic variables evaluated, the DPE amplitude associated with an f2 of moderate level (50 dB SPL) and a frequency corresponding to pure tone threshold was generally most predictive. DPE level was found to be weakly correlated with subject age and perhaps for this reason age was frequently included in discriminant functions. For our data, discriminant functions with one variable, two variables, or 5-10 variables showed no differences in predictive performance. This research suggests that DPE measures can reliably categorize pure tone thresholds as normal or impaired in large populations with varied cochlear hearing status.

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A method is presented here in which cochlear traveling wave delays are estimated through the measurement of distortion product emission phase (DPE) responses. This method assumes that the site of generation of DPEs is at the f2 place. Eighteen adult female and 18 adult male human ears, all with normal hearing, underwent DPE testing. For each ear, DPE phase responses were computed for eight values of f2 varying from 10 to 0.78 kHz. Linear DPE phase versus DPE frequency relationships were found. Estimates of traveling wave delay from the ear canal to the f2 place varied from about 1 ms for the 10-kHz place to 3.5 ms for the 0.78-kHz place. These estimates agree well with previous traveling wave delay estimates using electrocochleography. Test-retest comparisons of delay estimates were generally within 0.25 ms. In addition, within-subject interaural delay differences were smaller than between-subject interaural differences. Within-subject interaural delay differences were generally less than 0.5 ms. Male ears, when grouped together, had significantly longer delays (8%) to the 0.78-kHz place in comparison to female ears. The effect of DPE stimulus level on delay is presented for stimulus levels between 15 and 60 dB SPL. These data support the use of DPE phase responses as estimates of cochlear traveling wave delay. In comparison with electrophysiological and psychophysical techniques this method is purely cochlear-based and has the advantage of being rapid and noninvasive.

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We conducted two field studies using a behavioral consultation approach to reduce children's problem behaviors in public school settings. The first study consisted of a descriptive analysis in which the students and their teachers were observed during naturally occurring classroom activities. The results of the descriptive analysis provided hypotheses regarding the operant function of the students' problem behaviors. The hypotheses were tested in the second experiment directly through a modified experimental analysis and indirectly through an evaluation of the treatment effects. The interventions were designed to disrupt the inappropriate response-reinforcer relation by discontinuing contingent reinforcement (i.e., extinction), providing the reinforcer contingent on appropriate play behaviors, and teaching the students verbal skills functionally equivalent to the inappropriate response. The classroom teachers were trained to implement the interventions and conduct the experimental analyses during classroom activities in which the problem behaviors occurred most frequently. The interventions were effective in decreasing the students' problem behaviors while concurrently increasing their appropriate verbal skills.

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