Detector-Agnostic Phase-Space Distributions

The representation of quantum states via phase-space functions constitutes an intuitive technique to characterize light. However, the reconstruction of such distributions is challenging as it demands specific types of detectors and detailed models thereof to account for their particular properties and imperfections. To overcome these obstacles, we derive and implement a measurement scheme that enables a reconstruction of phase-space distributions for arbitrary states whose functionality does not depend on the knowledge of the detectors, thus defining the notion of detector-agnostic phase-space distributions. Our theory presents a generalization of well-known phase-space quasiprobability distributions, such as the Wigner function. We implement our measurement protocol, using state-of-the-art transition-edge sensors without performing a detector characterization. Based on our approach, we reveal the characteristic features of heralded single- and two-photon states in phase space and certify their nonclassicality with high statistical significance.

Quantum-enhanced interferometry with large heralded photon-number states

Quantum phenomena such as entanglement can improve fundamental limits on the sensitivity of a measurement probe. In optical interferometry, a probe consisting of N entangled photons provides up to aN enhancement in phase sensitivity compared to a classical probe of the same energy. Here, we employ high-gain parametric down-conversion sources and photon-number-resolving detectors to perform interferometry with heralded quantum probes of sizes up to N = 8 (i.e. measuring up to 16-photon coincidences). Our probes are created by injecting heralded photon-number states into an interferometer, and in principle provide quantum-enhanced phase sensitivity even in the presence of significant optical loss. Our work paves the way towards quantum-enhanced interferometry using large entangled photonic states.

Interobserver reliability of the gross motor performance measure: preliminary results

Although assessment of the quality of movement in children with cerebral palsy (CP) is difficult, the development of the Gross Motor Performance Measure (GMPM) has facilitated this process. In order to determine the interobserver reliability of the GMPM, 36 children with spastic neuromuscular disorders (mean age 7 years, range 4 to 15 years) were evaluated using four of the five dimensions of the GMPM. Percent Agreement, Intraclass Correlations, and Kappas were calculated by both dimension and attribute to determine reliability. In addition, reliability measures were evaluated over time to determine whether reliability improved with continual use of the GMPM. Overall, interobserver reliability was in the 'fair to good' category regardless of the reliability measure used in the analysis. Reliability scores improved over time with a greater number of individual item scores moving from the 'fair to good' category to the 'excellent' category. Results from this study indicate that it is possible to assess reliably the quality of movement in children with CP.

An individualized, sensitive frequency range for early detection of ototoxicity

OBJECTIVE

The aim of this study was to identify auditory frequencies at which serial threshold testing would provide the greatest sensitivity for early detection of ototoxicity. The overall objective is to develop a more time-efficient ototoxicity monitoring protocol.

DESIGN

Threshold data were analyzed from 370 hospitalized patients treated with aminoglycoside antibiotics (AMGs) or cisplatin (CDDP) who received serial auditory monitoring before, during, and after treatment at conventional (0.25 to 8 kHz) and high (9 to 20 kHz) frequencies.

RESULTS

For patients showing hearing changes due to ototoxicity, a frequency range was identified for its apparent high sensitivity to initial ototoxicity. This sensitive range is identified according to an individual's hearing threshold configuration, and is, therefore, unique for each patient. The range consists of five frequencies, generally separated by 1/6 octave, e.g., 8, 9, 10, 11.2, and 12.5 kHz. To determine frequencies and combinations of frequencies that were most often involved in ototoxicity detection, threshold data in the sensitive range were analyzed in detail. This analysis suggests that patients receiving treatment with AMG or CDDP can be monitored for hearing thresholds at only five frequencies, resulting in an 84% detection rate for AMG and 94% for CDDP compared with monitoring at all conventional and high frequencies.

CONCLUSIONS

This comprehensive analysis supports earlier observations that a sensitive, limited frequency range exists in which serial threshold monitoring will provide early warning of ototoxicity before effects in the speech frequency range. This finding is now being evaluated in a prospective investigation.

School-age children's and adolescents' adjustment when a parent has cancer

PURPOSE/OBJECTIVES

To describe school-age children's and adolescents' adjustment to parental cancer.

DESIGN

Retrospective population control.

SETTING

Screening cancer registries identified subjects at four Midwestern hospitals, including urban and rural settings of community and tertiary hospitals. All families were interviewed at home one time.

SAMPLE

A convenience sample of 116 school-age children (6-10 years) and adolescents (11-18 years) living in the home of a parent with cancer.

METHODS

Data were collected using two forms of the Child Behavior Checklist and an investigator-developed demographic form. The ill parent, the partner, and the adolescent rated the adjustment. This study's data were compared with population data, and comparisons were made among raters and with the existing literature.

MAIN RESEARCH VARIABLES

School-age children's and adolescents' adjustment.

FINDINGS

School-age children and adolescents of a parent with cancer have significantly more behavioral problems than were expected. The significant agreement among raters is of a modest magnitude but as strong as rater agreement reported in the literature.

CONCLUSIONS

Most school-age children and adolescents of a parent with cancer are well-adjusted, but a significant subset of youngsters is at risk for behavioral problems.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to assess ill parents' concerns about their youngsters, provide information to parents, adolescents, and school-age children, and institute appropriate referrals.

Culture and systems of oppression in abused women's lives

Women's experiences of abuse are shaped by the social and cultural contexts in which they live. Recognition of the complex ways in which culture and systems of oppression interact, creating qualitatively different abuse experiences, is important nursing knowledge. Of particular concern are the ways in which women are constrained in their efforts to combat abuse as they experience the harsh and alienating effects of racism, sexism, classism, and other forms of social injustice. An understanding of the ways in which race and ethnicity, class, language and citizenship, religion, and culture intersect and shape women's experiences of abuse is critical to the provision of culturally competent nursing care. This understanding is the springboard from which more effective assessment and intervention strategies with vulnerable abused women of diverse backgrounds can emerge.

Intrasubject reliability of high-frequency (9-14 kHz) thresholds: tested separately vs. following conventional-frequency testing

Retrospective analysis of hearing-threshold data from a multisite ototoxicity monitoring study identified an individualized range of predominantly high frequencies (> 8 kHz) that appeared to be highly sensitive to early threshold changes caused by ototoxicity. This suggested the potential for a limited-frequency monitoring protocol that could be conducted rapidly without compromising sensitivity to ototoxicity. Such testing would require high-frequency thresholds to be obtained independently, that is, without prior testing at conventional frequencies (0.25-8 kHz). This study was conducted to determine the test-retest reliability of isolated threshold testing in a "target" frequency range of high frequencies (9, 10, 11.2, 12.5, and 14 kHz) that represented a shortened ototoxicity monitoring test. Twenty normal-hearing subjects were evaluated over five sessions. During each session, subjects were tested in each of two conditions: (1) conventional frequencies (0.25-8 kHz) tested first, followed by target frequencies; and (2) target frequencies tested alone (isolation condition). Depending on test frequency, reliability of high-frequency thresholds was either unchanged or improved in the isolation condition. Although these results cannot be generalized to ill hospitalized patients, who may also have pre-existing hearing loss, they lay the groundwork for development of a time-saving limited-frequency test to monitor for ototoxicity in these patients.

Retrieval of famous names on a Rebus Riddle task by middle-aged and older subjects

This study compared the performances of 20 middle-aged and 20 older subjects on a Rebus Riddle task that required they retrieve the names of famous persons. Older subjects solved significantly more riddles and responded to prompts designed to aid riddle-solving efforts with significantly greater success than middle-aged subjects. Older subjects also had nonsignificantly faster riddle-solving times than middle-aged subjects. Similar riddles were difficult or easy for both groups. Superior performance of the older group appeared to be related to the age of the subject at the time the persons in the riddles had become famous.

Health status of bereaved parents

Forty-seven mothers and 33 fathers, representing 48 families, participated in a propective longitudinal study of the effects on family members of a child's dying. The purpose of this article is to describe parents' health during the terminal illness of their child and during the first year following their child's death from cancer. The Duke-UNC Health Profile was used to examine parents' health prior to and at three points in thime after the child's death. The bereavedparents' general health was compared to the health of normative sample of adults. The findings indicate that parents' health is not adversely affected by a child's death from cancer.

Morphological modeling via isosurfacing: the laryngeal skeleton of gekkonid lizards as a test case

A novel technique for modeling microscopic anatomical structures in three dimensions was developed as part of a survey of gekkonid laryngeal skeletal morphology (Reptilia: Gekkonidae). Excised larynges were transversely sectioned at 10 microns and stained using standard procedures. With a projection microscope, outline drawings of the sectioned laryngeal cartilages were made at regular intervals, depending on the rate and degree of structural change observed while sampling. The drawing set was digitized with a flatbed scanner, and aligned using 'NIH Image' for Macintosh computers. Physical connectivity between successive outlines was provided by inserting one or more artificial slices between those that had been digitized, and draping a skin of rendered contours over all of the interstitial spaces present in the template. The Application Visualization System, a general purpose visualization package for UNIX-based computer systems, was used to visualize and render the resulting 'isosurfaces', which appear as solid three-dimensional objects and can be viewed from any perspective. Since isosurfaced reconstructions can be based on as little as 20% of the cross-sections available, this procedure has the potential to be a valuable research tool for future morphological work at the microscopic level.

Reliability of auditory brainstem responses from sequenced high-frequency (> or = 8 kHz) tonebursts

An auditory brainstem response method is described for evoking responses to 4 high-frequency (8, 10, 12 and 14 kHz) tonebursts in the same amount of time normally required to obtain responses to single tonebursts. Reliability of responses to high-frequency toneburst stimuli presented in the conventional manner (one at a time) has been previously documented. In the present study, high-frequency tonebursts were presented to 20 normal-hearing subjects singly and in a 4-stimulus sequence. The reliability of resulting responses did not differ significantly between single- and multiple-stimulus test conditions. It is concluded that this sequenced-stimulus concept could be developed for use in serial monitoring of individuals receiving ototoxic agents as well as being broadly applicable to clinical situations in which patients cannot or will not respond voluntarily.

High-frequency toneburst-evoked ABR latency-intensity functions in sensorineural hearing-impaired humans

The latency-intensity functions (LIFs) of ABRs elicited by high-frequency (8, 10, 12, and 14 kHz) toneburst stimuli were evaluated in 20 subjects with confirmed 'moderate' high-frequency sensorineural hearing loss. Wave V results from clicks and tonebursts revealed all intra- and intersession data to be reliable (p > 0.05). Linear regression curves were highly significant (p < or = 0.0001), indicating linear relationships for all stimuli analyzed. Comparisons between the linear regression curves from a previously reported normal-hearing subject group and this sensorineural hearing-impaired group showed no significant differences. This study demonstrated that tonebursts at 8, 10, and 12 kHz evoked ABRs which decreased in latency as a function of increasing intensity and that these LIFs were consistent and orderly (14 kHz was not determinable). These results will contribute information to facilitate the establishment of change criteria used to predict change in hearing during treatment with ototoxic medications.

High-frequency audiometric monitoring strategies for early detection of ototoxicity

Therapeutic drugs such as the aminoglycoside antibiotics (AMG) and the chemotherapy agent cisplatin (CDDP) are known to cause irreversible hearing loss, typically affecting highest frequency hearing first with progression of loss to the lower frequency regions. Conventional (0.25-8 kHz) and high-frequency (9-20 kHz) serial hearing threshold monitoring was done in 123 hospitalized patients (222 ears) administered AMG or CDDP. Of ears showing a decrease in sensitivity corresponding with treatment, 62.5% demonstrated initial hearing loss solely in the high-frequency range, 13.5% first showed loss only in the conventional-frequency range, and 24.0% showed loss in both frequency ranges concurrently. Thus, if only high frequencies had been monitored, early change in auditory sensitivity would have been detected in 86.5% of these patients. Further analysis revealed a range of five frequencies, specific to each individual's hearing threshold configuration, in which initial ototoxicity appeared most likely to be detected. Testing only these five frequencies would have identified 89.2% of ears that showed change. The results of this study confirm the need to serially monitor auditory thresholds, especially in the high-frequency range, of patients receiving ototoxic drugs. A shortened five-frequency monitoring protocol is presented and suggested for use with patients unable to tolerate lengthy audiometric testing procedures.

The long-term effects of polymethylmethacrylate contact lens wear on the corneal endothelium

PURPOSE

The purpose of this study is to determine the long-term effects of polymethylmethacrylate (PMMA) contact lens wear on the corneal endothelium. The authors had noted previously advanced polymegethism and decreased cell densities in a few long-term PMMA contact lens wearers. They evaluated a large group of such lens wearers to determine the prevalence of polymegethism and reduced endothelial cell density within this lens-wearing population.

METHODS

The authors examined the morphologic characteristics of the corneal endothelium in 162 PMMA contact lens wearers or age-matched controls. Eighty-one subjects had worn contact lenses for more than 20 years.

RESULTS

Patients showed advanced polymegethism and pleomorphism compared with controls. Mean cell density in the contact lens-wearing group was not different from controls, but a significantly greater percentage of contact lens wearers (11%, 9 of 81 patients) had cell densities less than 2000 cells/mm2 compared with controls (2.5%, 2 of 81 patients), and were also significantly more likely to have severe polymegethism (coefficient of variation, > 0.60) and severe pleomorphism (frequency of hexagons < 40%).

CONCLUSION

This study is unique, in that it notes a subgroup of PMMA contact lens wearers who are more susceptible to significant morphometric changes and reduced endothelial cell densities with long-term contact lens use.

Reliability of histologic scoring for lupus nephritis: a community-based evaluation

OBJECTIVE

To determine the reliability of the National Institutes of Health (NIH)-modified semiquantitative histologic scoring system for lupus nephritis.

DESIGN

Cross-sectional study, repeated after 8 to 9 months.

SETTING

Four community hospitals and one university medical center.

PARTICIPANTS

Five pathologists, all experienced in reading renal biopsy specimens, assessed 25 specimens that had been obtained from patients with a clinical diagnosis of systemic lupus erythematosus and showed diffuse proliferative glomerulonephritis.

MEASUREMENTS

Biopsy specimens were scored independently and blindly by pathologists for components of nephritis chronicity and activity. Reliability was measured by percentage agreement, intraclass correlation coefficient or kappa statistic, and individual reader effect on the group arithmetic mean.

RESULTS

As scored by the readers, the mean chronicity index score varied from 2.3 to 4.8 on a 12-point scale (P = 0.001) and the mean activity index score varied from 5.8 to 11.4 on a 24-point scale (P = 0.0001). Pairs of readers gave scores within 1 point for the chronicity index and within 2 points for the activity index in 50% of cases, and risk group assignments based on chronicity index (three strata) and activity index (two strata) were concordant in 59% and 76% of cases, respectively. Intraclass correlation coefficients for inter-reader agreement were 0.58 for the chronicity index (P < 0.01) and 0.52 for the activity index (P < 0.01). Intrareader agreement was uniformly higher than inter-reader agreement, but mean intraclass correlation coefficients exceeded 0.70 for only 1 of the 10 index components. Repeated readings yielded chronicity index scores that were more than 1 point discordant in 45% of cases and activity index scores that were more than 2 points discordant in 43% of cases. Risk group assignment changed on the basis of chronicity index and activity index in 36% and 21% of cases, respectively.

CONCLUSIONS

In a nonreferral setting, the NIH-modified scoring system for lupus nephritis is only moderately reproducible and, if used to prognosticate renal outcome, may result in erroneous predictions of risk for renal failure and response to therapy.

The interval nature of an ordinal scale for measuring the marginal fracture of amalgam

The clinical performance of amalgam alloys over time has been assessed by measuring the extent of marginal fracture of restorations made from these alloys. Scales of photographs of restorations exhibiting varying degrees of marginal fracture have been used to make these assessments. The purpose of this study was to determine the relationship between the ordinal scale numbers of five photographs composing a commonly used scale (Mahler and Marantz, 1979) and the average width in micrometers of marginal fracture of the restorations in the photographs of this scale. In addition, a comparison was made between parametric and non-parametric statistical methods when applied to marginal fracture data. The results showed that four of the five photographs of this scale demonstrated a significant linear regression with marginal fracture width (R2 = 0.997; p = 0.002). The last photograph of the scale, which proved to be an outlier, was not used in the regression and was accommodated by an extrapolation procedure. Using previously gathered clinical data on the marginal fracture behavior of five amalgam alloys, the use of parametric statistical procedures (ANOVA and Scheffé's multiple comparison test) proved to be more discriminatory than the use of nonparametric procedures (Kruskal-Wallis and Dunn's Multiple comparison test) when tested at the same overall confidence level. Thus, having a photographic scale of an interval nature removes any doubt about using the more powerful technique of parametric statistics to evaluate the marginal fracture behavior of dental amalgams.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of evoked responses to high-frequency (8-14 kHz) tone bursts

Instrumentation to evaluate the auditory brainstem response to high-frequency (8-14 kHz) tone bursts has been developed in the Auditory Research Laboratory, Portland, Oregon VA Medical Center. This system is intended to monitor the audition of patients receiving ototoxic drugs who are unresponsive to behavioral test procedures. The reliability of responses obtained with the high-frequency tone-burst system was studied in 30 normal ears. Intrasubject variability of intersession data from response waves I, III, and V to tone bursts of frequencies 8, 10, 12, and 14 kHz was not significantly different from click response variability. The results of this study demonstrate the reliability of the ABR to these high-frequency tone-burst stimuli. This technique may provide early identification of hearing loss in unresponsive subjects receiving treatment with potentially ototoxic agents, thus allowing alternative treatments to minimize or prevent communicative handicap.

Variables affecting the auditory brainstem response: audiogram, age, gender and head size

Correlations between the ABR (auditory brainstem response) and the variables of hearing loss, gender, head size and age were determined in simple and multiple regression analyses in 334 ears. The stepwise multiple regression analyses for waves I, III and V of the ABR was used to determine the relative importance of the variables. Regression equations were calculated for the latency of each wave. Wave I latency for all subjects is best predicted by hearing threshold at 8 kHz, gender and age, in that order. Wave III latency depends upon hearing threshold at 4 kHz, age and gender. The latency of wave V is best predicted by gender, age and head diameter with threshold at 4 kHz being of minor importance. The I-V interval depends upon head diameter and threshold at 8 and 4 kHz with age of minor importance. Hearing loss at 8 kHz would shorten the I-V interval, while a loss at 4 kHz would be expected to lengthen the interval. Correlations of these variables with the amplitude of I, III and V are also described. Latency and amplitude are correlated with different subject variables suggesting differences in their generation.

The relative importance of head size, gender and age on the auditory brainstem response

Correlations between the ABR (auditory brainstem response) and subject characteristics of gender, age, and head diameter were established in simple and multiple regression analyses of normal hearing individuals. The simple regression tests demonstrated that head diameter and gender were significantly correlated with the latencies and amplitudes of waves I, III, and V and the I-V and III-V interpeak intervals. In nearly all cases, head diameter correlated more highly with the ABR waves than did gender. Males had longer latencies than females with comparable head diameter, suggesting that factors other than head size are differentiating them. Age was significantly correlated only with the latency of wave III. All significant subject variables also were compared simultaneously in a multiple regression analysis to determine their order of significance and relative contributions to the ABR wave latencies. This permitted the establishment of regression equations for each wave latency to predict the ABR with measurable subject characteristics.

Genetic differences in avoidance learning by Rattus norvegicus: escape/avoidance responding, sensitivity to electric shock, discrimination learning, and open-field behavior

The behaviors of rats selectively bred for either good or poor shuttle box avoidance learning were studied. The results of Experiment 1 indicated that the phenotypic difference in avoidance learning is not associated with differences in speed of escape or avoidance responding. Differences between the lines in frequency of intertrial responses (ITRs), which appear during training but not during pretest, suggest that ITRs in animals of the low-avoidance (SLA) line are more suppressed by electric shock than in animals of the high-avoidance (SHA) line. This result suggests that SLA animals may be more emotionally responsive than SHA animals. Experiment 2 demonstrated that the animals of the two lines do not differ in absolute sensitivity to electric shock, and Experiment 3 showed that the poor performance of the SLA line is not due to an inability to learn. Experiment 3 also provided evidence which suggests that the poor avoidance learning by SLA animals is due to their emotional reactivity. Observations of open-field behavior in Experiment 4 are consistent with this hypothesis. The major consistent correlate of the phenotypic difference in avoidance learning is greater emotionality or emotional reactivity in SLA than in SHA animals.

Prognosis for improved verbal communication in aphasic stroke patients

Information for predicting to what degree a patient will recover from aphasia has not been available to the physician. This study examined the role of 10 selected prognostic variables in relation to recovery of verbal communication in a homogeneous sample of treated aphasic patients. Terminal speech performance (TSP) could be discriminated 86% of the time by 6 variables; (1) initial severity of aphasia, (2) number of months after stroke, (3) auditory comprehension ability, (4) age, (5) speech fluency, and (6) general health. The predictive value of these variables was slightly higher (91.2%) for patients with good TSP than for those with poor TSP (82.6%).

Aphasic patients in a rehabilitation program: scheduling speech and language services

Eleven 10-item tests from the Porch Index of Communicative Ability (PICA), were administered to 14 aphasic adults participating in a rehabilitation program. Tests were given once in the morning and once in the afternoon. Results indicate that overall communicative functioning was significantly higher for morning assessments, although some individual patients did better in the afternoon. The primary implication of these results is the importance of consistency in scheduling patient contacts when measuring the effects of treatments rendered. Considerations in determining optimum schedules and aiding individual patients in compensating for reduced efficiency due to time of day are discussed.

Effects of scheduling on the communicative assessment of aphasic patients

This study determined the influence of morning and afternoon scheduling on the assessment of communicative skills of aphasic patients. Eight short-term (3 to 9 months post-onset) and eight long-term (12 or more months post-onset) aphasic subjects were administered 11 tests from the Porch Index of Communicative Ability (PICA) at specified times in the morning (A.M.) and afternoon (P.M.). Order of scheduling (A.M. first, P.M. second; P.M. first, A.M. second) was determined randomly but balanced between groups. Results indicated an absence of significant main effects for onset, scheduling, and test order; however, significant interactions between the scheduling and test-order factors were evidenced on the naming and auditory identification tests and on all overall measures. Analyses of these interactions revealed that patients scheduled first in the A.M. decreased their mean scores when assessed a second time in the P.M., whereas those scheduled first in the P.M., increased their scores when seen a second time in the A.M. Findings suggest that aphasic patients can be expected to do better on morning than afternoon assessments regardless of the order in which they are scheduled. Clinically, this indicates a need for consistency in the scheduling of periodic assessments for individual aphasic patients.

Ear lobe creases and heart disease

In 50 patients with coronary heart disease (CHD) and 38 controls, comparative data on age, sex, serum cholesterol level, hypertension, obesity, diabetes, smoking habits, and ear-lobe creases were analyzed statistically. After adjustment for age differences, the factors which chiefly distinguished the two groups were the incidences of smoking, obesity, diabetes, and ear-lobe creases. Of these, the ear-lobe crease seemed to be correlated best with CHD, and may prove to be a useful diagnostic sign.

Unit activity in posterior association cortex of cat

1. "Association" neurons in the posterior middle suprasylvian gyrus of cat were found to be predominantly polysensory, with 82% of the units in the chloralose-anesthetized preparation responding to auditory, visual, and somatic stimuli. There was no evidence of response differentiation associated with cortical depth distribution. Most units responded with a short-latency response (median 35-60 ms) to all stimulus modalities, with the response to visual stimulation occurring at the shortest latency. Among polysensory cells, almost half responded with equal probability to auditory, visual, and somatic stimulation. The visual stimulus was the most potent for those cells responding with a higher probability to a single modality. Varying degrees of response complexity were noted in some cells in terms of changes in responsivity over time, discharge to stimulus offset, and inhibition of spontaneous activity. The unitary discharge was seen to occur on the negative peak and slope of the locally recorded evoked potential. When only the larger amplitude spikes were analyzed, most of the unitary activity occurred on the negative peak of the evoked potential. Almost half of trimodally responsive cells displayed similar phase relationships between unitary activity and evoked potentials for all three modalities. The absolute refractory period for most cells was from 200 to 300 ms, with relative refractory periods extending up to 30 s...