The effects of demographics, functioning, and perceptions on the relationship between self-reported and objective measures of driving exposure and patterns among older adults.

The exploratory study reported here was intended to examine: how strongly subjectively reported driving avoidance behaviors (commonly referred to as self-regulation) and exposure were related to their objectively measured counterparts and whether it depended on the specific behavior; the extent to which gender and age play a role in the association between subjectively reported driving avoidance behaviors and exposure and their objectively measured counterparts; and the extent to which demographics, health and functioning, driving-related perceptions, and cognition influence the association between subjective and objective driving avoidance behaviors overall. The study used data from the Longitudinal Research on Aging Drivers (LongROAD) study, a multisite, prospective cohort study designed to generate empirical data for understanding the role of medical, behavioral, environmental, and technological factors in driving safety during the process of aging. Objective driving measures were derived from GPS/datalogger data from 2131 LongROAD participants' vehicles. The corresponding subjective measures came from a comprehensive questionnaire administered to participants at baseline that asked them to report on their driving exposure, patterns, and other aspects of driving. Several other variables used in the analyses came from the comprehensive questionnaire and an inperson clinical assessment administered to participants at baseline. A series of simple linear and logistic models were fitted to examine the relationship between the subjective and objective driving measures of interest, and a multivariable analysis was conducted to examine the potential role of selected factors in the relationship between objective and subjective driving avoidance behaviors. Results of the models are presented and overall findings are discussed within the context of the existing research literature.

Task-specific resistance training to improve the ability of activities of daily living-impaired older adults to rise from a bed and from a chair.

OBJECTIVES: To determine the effect of a 12-week intervention to improve the ability of disabled older adults to rise from a bed and from a chair. DESIGN: Subjects were randomly allocated to either a 12-week task-specific resistance-training intervention (training in bed- and chair-rise subtasks, such as sliding forward to the edge of a chair with the addition of weights) or a control flexibility intervention. SETTING: Seven congregate housing facilities. PARTICIPANTS: Congregate housing residents age 65 and older (n = 161, mean age 82) who reported requiring assistance (such as from a person, equipment, or device) in performing at least one of the following mobility-related activities of daily living: transferring, walking, bathing, and toileting. MEASUREMENTS: At baseline, 6 weeks, and 12 weeks, subjects performed a series of bed- and chair-rise tasks where the rise task demand varied according to height of the head of the bed, chair seat height, and use of hands. Outcomes were able or unable to rise and, if able, the time taken to rise. Logistic regression for repeated measures was used to test for differences between tasks in the ability to rise. Following log transformation of rise time, a linear effects model was used to compare rise time between tasks. RESULTS: Regarding the maximum total number of bed- and chair-rise tasks that could be successfully completed, a significant training effect was seen at 12 weeks (P = .03); the training effect decreased as the total number of tasks increased. No statistically significant training effects were noted for rise ability according to individual tasks. Bed- and chair-rise time showed a significant training effect for each rise task, with analytic models suggesting a range of approximately 11% to 20% rise-time (up to 1.5 seconds) improvement in the training group over controls. Training effects were also noted in musculoskeletal capacities, particularly in trunk range of motion, strength, and balance. CONCLUSIONS: Task-specific resistance training increased the overall ability and decreased the rise time required to perform a series of bed- and chair-rise tasks. The actual rise-time improvement was clinically small but may be useful over the long term. Future studies might consider adapting this exercise program and the focus on trunk function to a frailer cohort, such as in rehabilitation settings. In these settings, the less challenging rise tasks (such as rising from an elevated chair) and the ability to perform intermediate tasks (such as hip bridging) may become important intermediate rehabilitation goals.

Chair and bed rise performance in ADL-impaired congregate housing residents.

OBJECTIVES: To examine the ability of activity of daily living (ADL)-impaired older adults to successfully rise, and, when successful, the time taken to rise, from a bed and chair under varying rise task demands. SETTING: Seven congregate housing facilities SUBJECTS: Congregate housing residents (n = 116, mean age 82) who admitted to requiring assistance (such as from a person, equipment, or device) in performing at least one of the following mobility-related ADLs: transferring, walking, bathing, and toileting. METHODS: Subjects performed a series of bed and chair rise tasks where the rise task demand varied according to the head of bed (HOB) height, chair seat height, and use of hands. Bed rise tasks included supine to sit-to-edge, sit up in bed with hand use, and sit up in bed without hands, all performed from a bed where the HOB was adjusted to 0, 30, and 45 degrees elevations; roll to side-lying then rise (HOB 0 degrees); and supine to stand (HOB 0 degrees). Chair seat heights were adjusted according to the percent of the distance between the floor and the knee (% FK), and included rises (1) with hands and then without hands at 140, 120, 100, and 80% FK; (2) from a reclining (105 degrees at chair back) and tilting (seat tilted 10 degrees posteriorly) chair (100% FK); and (3) from a 80% FK seat height with a 4-inch cushion added, with and then without hands. Logistic regression for repeated measures was used to test for differences between tasks in the ability to rise. After log transformation of rise time, a linear effects model was used to compare rise time between tasks. RESULTS: The median total number of tasks successfully completed was 18 (range, 3-21). Nearly all subjects were able to rise from positions where the starting surface was elevated as long as hand use was unlimited. With the HOB at 30 or 45 degrees essentially all subjects could complete supine to sit-to-edge and sit up with hands. Essentially all subjects could rise from a seat height at 140, 120, and 100% FK as long as hand use was allowed. A small group (8-10%) of subjects was dependent upon hand use to perform the least challenging tasks, such as 140% FK without hands chair rise and 45 degrees sit up without hands. This dependency upon hand use increased significantly as the demand of the task increased, that is, as the HOB or seat height was lowered. Approximately three-quarters of the sample could not rise from a flat (0 degrees HOB elevation) bed or low (80% FK) chair when hand use was not allowed. Similar trends were seen in rise performance time, that is, performance times tended to increase as the HOB or chair seat elevation declined and as hand use was limited. Total self-reported ADL disability, compared to the single ADL transferring item, was a stronger predictor of rise ability and timed rise performance, particularly for chair rise tasks. CONCLUSIONS: Lowering HOB height and seat height increased bed and chair rise task difficulty, particularly when hand use was restricted. Restricting hand use in low HOB height or lowered seat height conditions may help to identify older adults with declining rise ability. Yet, many of those who could not rise under "without hands" conditions could rise under "with hands" conditions, suggesting that dependency on hand use may be a marker of progressive rise impairment but may not predict day-to-day natural milieu rise performance. Intertask differences in performance time may be statistically significant but are clinically small. Given the relationship between self-reported ADL disability and rise performance, impaired rise performance may be considered a marker for ADL disability. These bed and chair rise tasks can serve as outcomes for an intervention to improve bed and chair rise ability and might also be used in future studies to quantify improvements or declines in function over time, to refine physical therapy protocols, and to examine the effect of bed and chair design modifications on bed and chai

The age of the carbonates in martian meteorite ALH84001.

The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 +/- 0.04 billion years by rubidium-strontium (Rb-Sr) dating and 4.04 +/- 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as approximately 5 percent), whitlockite (trace), and orthopyroxene (approximately 95 percent). The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites. Therefore, this age does not distinguish between aqueous and impact origins for the carbonates.

Asteroidal water within fluid inclusion-bearing halite in an H5 chondrite, Monahans (1998)

Crystals of halite and sylvite within the Monahans (1998) H5 chondrite contain aqueous fluid inclusions. The fluids are dominantly sodium chloride-potassium chloride brines, but they also contain divalent cations such as iron, magnesium, or calcium. Two possible origins for the brines are indigenous fluids flowing within the asteroid and exogenous fluids delivered into the asteroid surface from a salt-containing icy object.

Calcium metabolism before, during, and after a 3-mo spaceflight: kinetic and biochemical changes.

The loss of bone during spaceflight is considered a physiological obstacle for the exploration of other planets. This report of calcium metabolism before, during, and after long-duration spaceflight extends results from Skylab missions in the 1970s. Biochemical and endocrine indexes of calcium and bone metabolism were measured together with calcium absorption, excretion, and bone turnover using stable isotopes. Studies were conducted before, during, and after flight in three male subjects. Subjects varied in physical activity, yet all lost weight during flight. During flight, calcium intake and absorption decreased up to 50%, urinary calcium excretion increased up to 50%, and bone resorption (determined by kinetics or bone markers) increased by over 50%. Osteocalcin and bone-specific alkaline phosphatase, markers of bone formation, increased after flight. Subjects lost approximately 250 mg bone calcium per day during flight and regained bone calcium at a slower rate of approximately 100 mg/day for up to 3 mo after landing. Further studies are required to determine the time course of changes in calcium homeostasis during flight to develop and assess countermeasures against flight-induced bone loss.

Determining dental checkup frequency.

BACKGROUND: The authors assessed the dental checkup frequency of adults living in the Detroit tricounty area and identified demographic, access and subjective factors associated with visits to a dentist made not because of a dental problem. METHODS: Data are from a 1994 probability-based sample of adults who were interviewed and received an in-home oral examination. The authors used the variables of age, sex, education level, income level, dental insurance status, usual place for care, objective measures of oral health, and subjective assessments of health, pain and dental anxiety to predict the frequency of dental checkups. RESULTS: The authors found that differences in dental checkup behavior were related to demographics, access to dental care, subjective ratings of oral and general health and other self-assessments, and clinical parameters of oral health. In multiple logistic regression analysis considering all variables simultaneously, sex, income, having a usual place for care and level of dental care anxiety were found to be associated with having dental checkups. The authors determined the statistical significance level at P < .05. CONCLUSIONS: A total of 69.7 percent of the study population reported having had a dental checkup at least once a year in the past five years. The authors found that four factors associated with infrequent dental checkups: being male, having lower income levels, not having a usual place for care and being anxious about receiving dental care. PRACTICE IMPLICATIONS: Dental health professionals should consider the correlates of dental checkup frequency identified in this study and the usefulness of proposed strategies to increase and sustain regular preventive visitation patterns in their own patient populations.

Daily boron intake from the American diet.

Interest in boron as a naturally occurring trace element nutrient from the food supply is increasing. Mounting evidence suggests that boron is essential to human beings. This study explores the major food and beverage contributors of boron and estimates of daily boron intake from the American diet. Previous estimates in the literature of dietary boron consumption are based on limited foods and population segments. In this study we provide a more comprehensive assessment of boron consumption by the US population. A boron nutrient database of 1,944 individual foods was developed. These foods represent 95.3% by weight of all foods consumed in the US Department of Agriculture 1989-1991 Continuing Survey of Food Intakes by Individuals (1989-1991 CSFII). The Boron Nutrient Database (version 1.0) was then linked to the 3-day food records of 11,009 respondents to the 1989-1991 CSFII to generate the average daily boron intake for each person. The weighted 5th percentile, median, mean, and 95th percentile boron intakes, respectively, are 0.43, 1.02, 1.17 and 2.42 mg/day for men; 0.33, 0.83, 0.96 and 1.94 mg/day for women; and 0.40, 0.86, 1.01 and 2.18 mg/day for pregnant women. For vegetarian adults, these intakes are 0.46, 1.30, 1.47 and 2.74 mg/day for men and 0.33, 1.00, 1.29 and 4.18 mg/day for women. The top 2 boron contributors, coffee and milk, are low in boron, yet they make up 12% of the total boron intake by virtue of the volume consumed. Among the top 50 boron contributors, peanut butter, wine, raisins, peanuts, and other nuts are high in boron. As more data become available on daily boron requirements, the results of this study may be used to assess whether Americans' daily intake of boron is adequate.

Factors associated with dental anxiety.

This study assessed dental anxiety in adults living in the Detroit tricounty area and identified factors associated with it. The prevalence of dental anxiety was 10.0 percent. Regression analysis revealed six factors associated with dental anxiety: unfavorable attitudes toward dentists, infrequent checkups, dissatisfaction with one's month, small numbers of filled surfaces, being female and lower income. Dentists should be aware of these factors when assessing dental anxiety in their patient populations.

Multicountry estimation of dietary boron intake.

Dietary Reference Intakes are not yet established for boron (B), a naturally occurring trace element in the human diet. Estimated dietary B intakes provide useful information for planning and assessing diets in healthy populations. The countries selected for this study represent a wide variety of dietary patterns and have adequate nutrient databases (with the exception of B) and food consumption data. Large-scale nationwide survey data were provided by the US (1989-1991) and Germany (1985-1989). Survey data from rural agricultural communities of Mexico and Kenya were provided by the Human Nutrition Collaborative Research Support Program (1983-1986). A B nutrient database was created to include B concentrations for the foods consumed in each country. It incorporates B analytical data from various sources in the US, Finland, UK, Italy, Japan, and China. Each person's average daily B intake was estimated by linking the B database with the survey food records. Average dietary intake estimates were then generated for various age and sex groups. The estimates for adults in the US, Germany, Mexico and Kenya, respectively, are 1.11, 1.72, 2.12, and 1.95 mg B/d for males and 0.89, 1.62, 1.75, and 1.80 mg B/d for females. Foods that are major contributors to the B intake of each country were also identified.

Adult age-group differences in recall for the literal and interpretive meanings of narrative text.

This study examined age differences in recall for the literal and interpretive meanings of narrative text. Following presentation of one of two stories rich in both literal and interpretive content, younger (mean age = 19.2 years) and older (mean age = 72.2 years) adults were asked to retell and to interpret the story. Response task order was counterbalanced across participants. When asked to retell a story as close to the original as possible, the younger adults recalled more of the literal propositional content than did the older adults in the retell-first, although not in the interpret-first, condition. In addition, both older and younger adults recalled more of the main ideas (gist) relative to the details. When asked to interpret the same story, more older than younger adults produced deep and synthetic representations of the story's interpretive meanings. In addition, there was a clear preference among the older age group for deep-synthetic responding. Although more younger than older adults produced analytic interpretations, within the younger group there was no clear preference for either an analytic or a deep-synthetic style.

Evaluation and use of an index of oral health status.

OBJECTIVES: The goals of this investigation were (1) to evaluate the Oral Health Status Index in relation to demographic characteristics, socioeconomic status, and preventive behaviors of an adult population; and (2) to understand how individual index components performed as indicators of oral health status compared to the composite index. METHODS: The Oral Health Status Index (OHSI) was used on a probability sample of adults, aged 18-93 years, living in the Detroit tricounty area. Data were collected on 509 subjects via in-home dental examinations. Bivariate and multivariate analyses were used to compare the OHSI and its components, including decayed, missing, and replaced teeth, free ends, and moderate and severe periodontal disease measures. RESULTS: The mean OHSI score for subjects was 77.3 (SE = 1.83) with a range of -8.0 to 100.0. In regression analyses, OHSI scores were positively correlated with subjects' education level, self-rated oral health scores, and frequency of dental checkups and negatively correlated with age, nonwhite race, and smoking. Of the index components, missing teeth performed well as an indicator of oral health status. Missing teeth were positively correlated with age, nonwhite race, and smoking and negatively correlated with education level, self-rated oral health, and use of Medicaid. About 53 percent of variance in OHSI scores was explained by the multivariate models, compared to 46 percent for missing teeth. CONCLUSIONS: Choosing an indicator of oral health status likely will depend upon the characteristics of the population to be studied. As a composite measure of oral health status, the OHSI performed acceptably; however, missing teeth, an index component, also worked well. Continued evaluation of the OHSI is warranted.

Calcium kinetics with microgram stable isotope doses and saliva sampling.

Studies of calcium kinetics require administration of tracer doses of calcium and subsequent repeated sampling of biological fluids. This study was designed to develop techniques that would allow estimation of calcium kinetics by using small (micrograms) doses of isotopes instead of the more common large (mg) doses to minimize tracer perturbation of the system and reduce cost, and to explore the use of saliva sampling as an alternative to blood sampling. Subjects received an oral dose (133 micrograms) of 43Ca and an i.v. dose (7.7 micrograms) of 46Ca. Isotopic enrichment in blood, urine, saliva and feces was well above thermal ionization mass spectrometry measurement precision up to 170 h after dosing. Fractional calcium absorptions determined from isotopic ratios in blood, urine and saliva were similar. Compartmental modeling revealed that kinetic parameters determined from serum or saliva data were similar, decreasing the necessity for blood samples. It is concluded from these results that calcium kinetics can be assessed with micrograms doses of stable isotopes, thereby reducing tracer costs and with saliva samples, thereby reducing the amount of blood needed.

Control of red blood cell mass during spaceflight.

NASA: Data are reviewed from twenty-two astronauts from seven space missions in a study of red blood cell mass. The data show that decreased red cell mass in all astronauts exposed to space for more than nine days, although the actual dynamics of mass changes varies with flight duration. Possible mechanisms for these changes, including alterations in erythropoietin levels, are discussed.^ieng

Rapid accretion and early differentiation of Mars indicated by 142Nd/144Nd in SNC meteorites.

Small differences in the ratio of neodymium-142 to neodymium-144 in early formed mantle reservoirs in planetary bodies are the result of in situ decay of the extinct radionuclide samarium-146 and can be used to constrain early planetary differentiation and therefore the time scale of planetary accretion. The martian meteorite Nakhla (approximately 1.3 billion years old), the type sample of the nakhlite subgroup of the Shergottite-Nakhlite-Chassigny (SNC) meteorites, exhibits a 59 +/- 13 parts per million excess in the ratio of neodymium-142 to neodymium-144 relative to normal neodymium. This anomaly records differentiation in the martian mantle before 4539 million years ago and implies that Mars experienced no giant impacts at any time later than 27 million years after the origin of the solar system.

Specificity of the American Urological Association voiding symptom index: comparison of unselected and selected samples of both sexes.

The American Urological Association voiding symptom index questionnaire for benign prostatic hypertrophy was administered to an elderly unselected sample and a selected urology clinic sample of both sexes to investigate the ability of this instrument to identify prostatic pathological conditions. The female subjects in these cohorts provided a control. In the large unselected sample the male subjects scored statistically higher in only 2 categories, weak stream (487 subjects) and strain (507) (p < 0.05 for both categories). The clinical significance of these scores is questionable, however, since they were low (less than 2 of 5). In the selected group (145 subjects) the female subjects showed a higher total mean score due to the contribution of statistically higher irritative scores (p < 0.05). We conclude that the American Urological Association voiding symptom index does not specifically identify prostatic pathological conditions, and that elderly men and women have similar voiding symptom scores. Therefore, treatment that results in improvement in symptom scores may not specifically affect the prostate. Other factors, such as an aging detrusor, changes in physiological production of urine or other unknown factors, may contribute to the symptoms.

Relationships between self-reported physical and mental health and intelligence performance across adulthood.

One hundred and twenty-seven adults between 20 and 90 years of age were tested on the Wechsler Adult Intelligence Scale for their digit span memory (forward and backward), fluid intelligence (block design and digit symbol), and crystallized intelligence (vocabulary and information), as well as assessed for self-reported health (Cornell Medical Index, Zung Depression Scale, health habits, and self-ratings of physical and mental health). As expected, across the entire age range there was no correlation between age and digit span memory (r = .03), a strong negative correlation between age and fluid intelligence (r = -.78), and a modest positive correlation between age and crystallized intelligence (r = .27). In addition, older adults reported more physical (r = .36) and mental (r = .32) health problems than did younger adults. Of special interest was the finding that both self-reported physical and mental health accounted for significant variance in intelligence performance, particularly in older adults. Moreover, self-reported health accounted for a considerable portion of observed variance, even when age differences in self-reported health were statistically controlled.

Isotopic composition of rare gases in lunar samples.

Data from total melt and step-by-step heating experiments on the Apollo 11 lunar samples suggest a close affinity between lunar and meteoritic rare gases. Trapped neon-20/neon-22 ratios range from 11.5 to approximately 15, resembling those for the gas-rich meteorites. Trapped krypton and xenon in the lunar fines and in the carbonaceous chondrites are similar except for an interesting underabundance of the heavy isotopes in both lunar gases which suggests that the fission component found in carbonaceous chondrites is depleted in lunar material. Spallation gases are in most cases quite close to meteoritic spallation gases in isotopic composition.