Longitudinal findings from the Normative Aging Study: III. Personality, individual health trajectories, and mortality.

Individual differences in physical and psychological health trajectories were examined in 1,515 Normative Aging Study men. Mean age at baseline was 47.15 years (range = 28-80), and average follow up was 18.55 years (range = 8-25). Both linear and nonlinear growth curves were estimated with random-effects models and then clustered to identify patterns of change. Men whose physical health trajectories were characterized by high, increasing symptoms were higher in hostility and anxiety, were overweight, and smoked. Those whose trajectories were characterized by low symptoms were emotionally stable, educated, nonsmokers, and thin. Men with high, stable psychological trajectories had high hostility; those with low, stable trajectories had high emotional stability; those with moderate anxiety levels had nonlinear trajectories with peaks in psychological symptoms at different life stages. Personality had life-long effects on health trajectories, but these effects varied across traits and health outcomes.

Certification of the methylmercury content in SRM 2977 mussel tissue (organic contaminants and trace elements) and SRM 1566b oyster tissue.

The methylmercury content in two new marine bivalve mollusk tissue Standard Reference Materials (SRMs) has been certified using results of analyses from the National Institute of Standards and Technology (NIST) and two other laboratories. The certified concentrations of methylmercury were established based on the results from four and six different (independent) analytical methods, respectively, for SRM 1566b Oyster Tissue (13.2 +/- 0.7 microg/kg) and SRM 2977 Mussel Tissue (organic contaminants and trace elements) (36.2 +/- 1.7 microg/kg). The certified concentration of methylmercury in SRM 1566b is among the lowest in any certified reference material (CRM).

Estimating the root mean square of a wave front and its uncertainty.

The root mean square (rms) of the surface departure or wave-front deformation is an important value to extract from an optical test. The rms may be a tolerance that an optical fabricator is trying to meet, or it may be a parameter used by an optical designer to evaluate optical performance. Because the calculation of a rms involves a squaring operation, the rms of the measured data map is higher on average than the rms of the true surface or wave-front deformation, even if the noise is zero on average. The bias becomes significant as the scale of the noise becomes comparable to the true surface or wave-front deformation, as can be the case in the testing of ultraprecision optics. We describe and demonstrate a simple data analysis method to arrive at an unbiased estimate of the rms and a means to determine the measurement uncertainty.

A Careful Consideration of the Calibration Concept.

This paper presents a detailed discussion of the technical aspects of the calibration process with emphasis on the definition of the measurand, the conditions under which the calibration results are valid, and the subsequent use of the calibration results in measurement uncertainty statements. The concepts of measurement uncertainty, error, systematic error, and reproducibility are also addressed as they pertain to the calibration process.

Standard Reference Material (SRM 1990) For Single Crystal Diffractometer Alignment.

An international project was successfully completed which involved two major undertakings: (1) a round-robin to demonstrate the viability of the selected standard and (2) the certification of the lattice parameters of the SRM 1990, a Standard Reference Material(®) for single crystal diffractometer alignment. This SRM is a set of ≈3500 units of Cr-doped Al2O3, or ruby spheres [(0.420.011 mole fraction % Cr (expanded uncertainty)]. The round-robin consisted of determination of lattice parameters of a pair of crystals: the ruby sphere as a standard, and a zeolite reference to serve as an unknown. Fifty pairs of crystals were dispatched from Hauptman-Woodward Medical Research Institute to volunteers in x-ray laboratories world-wide. A total of 45 sets of data was received from 32 laboratories. The mean unit cell parameters of the ruby spheres was found to be a=4.7608 ű0.0062 Å, and c=12.9979 ű0.020 Å (95 % intervals of the laboratory means). The source of errors of outlier data was identified. The SRM project involved the certification of lattice parameters using four well-aligned single crystal diffractometers at (Bell Laboratories) Lucent Technologies and at NRC of Canada (39 ruby spheres), the quantification of the Cr content using a combined microprobe and SEM/EDS technique, and the evaluation of the mosaicity of the ruby spheres using a double-crystal spectrometry method. A confirmation of the lattice parameters was also conducted using a Guinier-Hägg camera. Systematic corrections of thermal expansion and refraction corrections were applied. These rubies- are rhombohedral, with space group [Formula: see text]. The certified mean unit cell parameters are a=4.76080±0.00029 Å, and c=12.99568 ű0.00087 Å (expanded uncertainty). These certified lattice parameters fall well within the results of those obtained from the international round-robin study. The Guinier-Hägg transmission measurements on five samples of powdered rubies (a=4.7610 ű0.0013 Å, and c = 12.9954 ű0.0034 Å) agreed well with the values obtained from the single crystal spheres.

Certification by the Karl Fischer method of the water content in SRM 2890, Water Saturated 1-Octanol, and the analysis of associated interlaboratory bias in the measurement process.

The calibration of Karl Fischer instruments and reagents and the compensation for instrumental bias are essential to the accurate measurement of trace levels of water in organic and inorganic chemicals. A stable, nonhygroscopic standard, Water Saturated Octanol, which is compatible with the Karl Fischer reagents, has been prepared. This material, Standard Reference Material (SRM) 2890, is homogeneous and is certified to contain 39.24 +/- 0.85 mg water/mL (expanded uncertainty) of solution (47.3 +/- 1.0 mg water/g solution, expanded uncertainty) at 21.5 degrees C. The solubility of water in -octanol has been shown to be nearly constant between 10 degrees C and 30 degrees C (i.e., within 1% of the value at 21.5 degrees C). The results of an interlaboratory comparison exercise illustrate the utility of SRM 2890 in assessing the accuracy and bias of Karl Fischer instruments and measurements.

An Approach to Combining Results From Multiple Methods Motivated by the ISO GUM.

The problem of determining a consensus value and its uncertainty from the results of multiple methods or laboratories is discussed. Desirable criteria of a solution are presented. A solution motivated by the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM) is introduced and applied in a detailed worked example. A Bayesian hierarchical model motivated by the proposed solution is presented and compared to the solution.

Frequency-switched heterodyne cavity ringdown spectroscopy.

When the frequency of light coupled into a cavity is suddenly shifted, the radiation emanating from the input port of the previously excited cavity can beat with the reflection of the frequency-shifted input on the surface of a photodetector. When the beat frequency is stable, the time decay of the resulting optical heterodyne signal can be used to measure intracavity absorption spectra with near quantum-limited sensitivity.

Methods of teaching stapedectomy.

OBJECTIVES: Establish a better method of teaching residents stapes surgery, with the goal of improving surgical outcome. STUDY DESIGN: A stapes surgery teaching module was developed with specific criteria to evaluate resident performance. A prospective study of stapes surgery performed by teaching module trained residents was compared with a retrospective review of stapes surgery performed by non-teaching module trained residents. METHODS: Four residents naive to stapes surgery were assigned to a stapes surgery teaching module. Stapedectomy of 20 temporal bones per resident, with six 3-hour laboratory sessions, was performed. Laser (CO2 and argon) as well as mechanical techniques were used. Specific scoring criteria were applied to measure performance. Results of actual stapes surgery of teaching module trained residents were compared with those of a comparable group of non-teaching module trained residents. RESULTS: Laser techniques in the laboratory resulted in statistically significantly better scores by defined criteria than mechanical techniques. Results of actual stapes surgery performed by teaching module trained residents demonstrated a trend toward better surgical results, although this was not statistically significant. CONCLUSIONS: Graded operative experience and standard temporal bone surgery courses may not adequately prepare residents for stapes surgery. A teaching module with criteria to evaluate performance better prepares residents for this delicate procedure. Lasers provide a significant advantage in the laboratory model and should be used by residents at surgery. Residents not wishing to perform stapes surgery because of career pathway should be encouraged to turn over their cases to fellow residents.

Endoscopic/Microscopic approach to sphenopetroclival complex: an anatomical study.

A dilemma presents itself to the otoneurologist and neurosurgeon when determining the least invasive surgical approach to giant cholesterol cysts (GCC) of the petrous apex of the temporal bone. These lesions can be diagnosed with a fair degree of certainty with imaging studies. Transmastoid and subcochlear approaches may be inadequate to access these lesions, and the transcochlear approach results in the sacrifice of hearing. A minimally invasive, combined microscopic and endoscopic sublabial transsphenoid approach to drain and marsupalize these lesions has been chosen by the authors in those cases that are anatomically possible. The purpose of this article is to establish the feasibility of exenterating anterior petrous apex cells by way of this approach, and to better conceptualize the anatomy of the Spheno-Petro-Clival Complex (SPC). Ten Fresh cadaveric "whole head" specimens were dissected with, endoscopic/microscopic control, through midline, sublabial, transseptal, and transsphenoidal routes to the petrous apex. The three-dimensional relationships of the sphenoid sinus, petrous apex, and the clivus were further demonstrated by dissections of the same specimens from the posterior fossa. Sagittal cut sections were also performed. After confirming the feasibility of this approach by dissections, the technique was adopted for performing drainage of GCC of the petrous apex in clinical cases.

Age, cohort and period effects on alcohol consumption and problem drinking: findings from the Normative Aging Study.

OBJECTIVE: We examined whether alcohol consumption and problem drinking decreased with age or if the reported declines were actually cohort and/or period effects. METHOD: We utilized data from the Normative Aging Study, assessing 1,267 men three times over an 18-year period (1973, 1982, 1991). Men were divided into five 9-year birth cohorts; age ranged from 46 to 72. RESULTS: Sequential analyses using repeated measures ANOVAs showed significant age, cohort and period effects. Although there was a tendency for alcohol consumption to decline with age, this was not true for all cohorts. Men born between 1910 and 1918 increased from an average of 350 to 440 drinks per year from their fifties to their sixties. The younger cohorts tended to report both more consumption and more problems. However, period had the most consistent effect in this study. There was an increase in problems and in consumption during the 1970s but a decrease in the 1980s, with the exception of the youngest cohort (1937-1945) who reported more problems in the 1991 assessment despite lower consumption. CONCLUSIONS: Age-related change in both consumption and problems varied depending upon which cohort or time period was assessed. Thus, drinking patterns are a complex amalgam of individual aging and societal change.

Calculation of Measurement Uncertainty Using Prior Information.

We describe the use of Bayesian inference to include prior information about the value of the measurand in the calculation of measurement uncertainty. Typical examples show this can, in effect, reduce the expanded uncertainty by up to 85 %. The application of the Bayesian approach to proving workpiece conformance to specification (as given by international standard ISO 14253-1) is presented and a procedure for increasing the conformance zone by modifying the expanded uncertainty guard bands is discussed.

Continuous-wave frequency tripling and quadrupling by simultaneous three-wave mixings in periodically poled crystals: application to a two-step 1.19-10.71-microm frequency bridge.

We observed cw third-harmonic generation in a periodically poled LiNbO(3) crystal by cascading optimally phase-matched second-harmonic and sum-frequency generation. Other processes, such as fourth-harmonic generation, are allowed by the flexibility of quasi-phase matching. We demonstrate a divide-by-nine (1.19- 10.71-microm) frequency chain that uses only two lasers.

DNA analysis of human cholesteatomas.

HYPOTHESIS: The hypothesis tested in this article is that if cholesteatomas are a low-grade squamous cell neoplasm, then evidence of genetic instability, in the form of abnormal or aneuploid amounts of DNA, should be evident. BACKGROUND: Cholesteatoma is a destructive lesion of the middle ear and/or mastoid process that produces complications by erosion of the temporal bone. The clinical hallmarks of cholesteatomas, namely invasion, migration, uncoordinated proliferation, altered differentiation, aggressiveness, and recidivism, are traits typically associated with the neoplastic cell. However, there is little evidence to support or refute the speculation that cholesteatomas are a low-grade squamous cell neoplasm. the existence of defects in the genetic complement of the major cellular constituents comprising a cholesteatoma, fibroblasts and keratinocytes, would support the speculation that cholesteatomas are a neoplasm, since cancers commonly manifest quantitative and qualitative alterations in the normal euploid complement of genetic information, resulting in a cell that has an abnormal or aneuploid amount of DNA. METHODS: DNA content (ploidy) within cholesteatoma tissues was measured by flow cytometry and image analysis. RESULTS: The DNA content of 11 human cholesteatomas and nine postauricular skin specimens was analyzed using flow cytometry, while the DNA content of 10 cholesteatoma specimens was analyzed using image analysis. Interpretable data was obtained from 10 cholesteatoma specimens and six postauricular skin specimens. One cholesteatoma specimen demonstrated an abnormal aneuploid DNA content, whereas the remaining nine cholesteatomas and the six postauricular skin specimens demonstrated a normal euploid DNA content. CONCLUSIONS: We conclude that, due to the lack of overt genetic instability, as evidenced by the presence of a normal euploid DNA content, cholesteatomas are not low-grade neoplasms.

Free-induction decay in molecular iodine measured with an extended-cavity diode laser.

The free-induction decay (FID) technique combined with broadly tunable lasers offers a convenient way to survey molecular dephasing times. We measured FID's in molecular iodine by frequency switching an extended-cavity diode laser with a small current modulation. These decay times provide valuable information on the Doppler-free linewidths for frequency-standard applications.

Canalplasty.

Canal stenosis and atresia can result from a number of causes, including congenital, inflammatory, neoplastic and iatrogenic pathologic conditions. Canalplasty is an eclectic collection of techniques designed to recreate a patent and trouble-free external canal. Despite the large number of etiologies, the principles of canalplasty are the same. The goal is the creation of a widely patent and physiologically intact canal wall. Both the bony and cartilaginous portions must be addressed surgically. Care should be taken to preserve the normal skin and adnexa for lining the canal, but if this is not adequate, skin grafts should be used to prevent healing by secondary intent. Overcorrection of stenosis is advised. We have presented our basic technique for canalplasty and discussed its alteration for specific disorders.

Beta-2 transferrin: limitations of use as a clinical marker for perilymph.

Beta-2 transferrin is a protein marker that can be used in the clinical setting to reliably identify the presence of cerebrospinal fluid (CSF). Recent literature has suggested that beta-2 transferrin can also be used as a clinical marker for perilymph. This study investigates the use of a beta-2 transferrin assay as a method to identify the presence of perilymph. Twenty-two patients were enrolled in the study. Fluid samples were obtained intraoperatively and tested for the presence of beta-2 transferrin. As expected, four CSF samples collected were positive for beta-2 transferrin; however, four known perilymph samples collected from patients undergoing cochlear implantation were negative for beta-2 transferrin, seven of nine known perilymph samples obtained during stapedectomies were negative for beta-2 transferrin, and four of five samples collected during middle ear explorations for fistula were negative for beta-2 transferrin. With current methodology beta-2 transferrin does not appear to be a reliable clinical marker for perilymph in the operative setting.

Assessing psychopathic attributes in a noninstitutionalized population.

The present study examined antisocial dispositions in 487 university students. Primary and secondary psychopathy scales were developed to assess a protopsychopathic interpersonal philosophy. An antisocial action scale also was developed for purposes of validation. The primary, secondary, and antisocial action scales were correlated with each other and with boredom susceptibility and disinhibition but not with experience seeking and thrill and adventure seeking. Secondary psychopathy was associated with trait anxiety. Multiple regression analysis revealed that the strongest predictors of antisocial action were disinhibition, primary psychopathy, secondary psychopathy, and sex, whereas thrill and adventure seeking was a negative predictor. This argues against a singular behavioral inhibition system mediating both antisocial and risk-taking behavior. These findings are also consistent with the view that psychopathy is a continuous dimension.