Inter- and intra-individual variation in applied force when listening at a surface, and resulting variation in earprints.

We aimed to explore the level of inter- and intra-individual variation in applied force when listening at a surface, and assess the resulting variation in earprints. We further intended to identify possible sources of this variation. Forty subjects each listened twenty-four times at a surface while applied force was recorded. In between efforts the level and frequency of the target sound, and the level of ambient noise were varied. Each listening effort was characterized by two values: the mean of a series of force recordings ('functional force') and the highest force reading of the effort ('peak value'). A mixed model analysis of variance revealed that repetition during multiple efforts of listening and the level of the target sound significantly affected both values for applied force. The frequency of the target sound affected the peak value, but we assume this was due to confounding effects. The level of ambient noise did not affect applied force. To explore the correlation between values for applied force of various efforts by single ear, the intra-class correlation coefficient was calculated. For functional force it was 0.80; for the peak value it was 0.79. To study intra-individual variation in earprints, five prints from each ear were lifted and studied. Variation in prints is discussed.

One-leg standing balance and functional status in an elderly community-dwelling population in northeast Italy.

BACKGROUND AND AIMS: Development of simple and accurate indicators of frailty is an important research goal in aging societies. One-leg standing balance (OLSB) has been proposed as a component of a clinical index of frailty. METHODS: We analyzed relationships between results of OLSB testing and multiple health risk factors and impairment/disability indicators in a sample of elderly subjects (N=102) participating in the Anchyses Project. Subjects were aged >65, lived in a home for the aged in Rovigo, Italy, and had no ADL dependencies or recent acute illnesses. RESULTS: More than half (53%) failed the OLSB test while 36% were able to balance without difficulty. Significant differences were observed among OLSB performance groups in forced vital capacity (p=0.025), dynamometry (p=0.001), age, physical activity, and IADL dependency (all p<0.001). CONCLUSIONS: OLSB performance is a marker of frailty and thus a potentially useful predictor of functional decline.

Palaeodemography of the Nasca valley: reconstruction of the human ecology in the southern Peruvian coast.

This study is based on skeletons and mummies belonging to 582 individuals excavated at sites of Pueblo Viejo, Cahuachi, Estaqueria and Atarco in the Nasca valley, South Coast of Peru. Archaeological evidence distinguishes three cultural phases: Nasca (400 BC-550 AD), Wari (600-1100 AD) and Chincha (1100-1412 AD). Since the Chincha human remains were too exiguous (27 individuals), only Nasca and Wari were considered. For the Nasca population, sex ratio was 113 men to 100 women (53% of males); for the Wari population, sex ratio was 117 men to 100 women (54% of males). The palaeodemographic data show that the infant mortality rate was 33@1000 for Nasca and 105@1000 for Wari. Life expectancy was 38-43 years for Nasca and 31-36 years for Wari. Death percentages in all the age groups increased from Nasca to Wari phase. ANOVA and t-test for paired comparison were applied in order to examine if dental and bone ages were statistically different. Long bones and teeth showed an allometric development, and the age estimated from the tooth formation and eruption was generally higher than the age estimated from the maximum lengths of long bones. The anthropological study of the Nasca valley skeletal populations confirmed the archaeological hypothesis of worse conditions of the Wari population in comparison with the previous Nasca people.

The coronal pulp cavity index: a biomarker for age determination in human adults.

The correlation between reduction of the coronal pulp cavity and chronological age was examined in a sample of 846 intact teeth from 433 individuals of known age and sex. Panoramic (rotational) radiography was used to measure the height (mm) of the crown (CH = coronal height) and the height (mm) of the coronal pulp cavity (CPCH = coronal pulp cavity height) of 425 premolars and 421 molars from 213 males and 220 females. The tooth-coronal index (TCI) after Ikeda et al. [1985] Jpn. J. For. Med. 39:244-250) was computed for each tooth and regressed on real age. The correlation coefficients ranged from -0.92 (molars, combined sample, right side) to -0.87 (female molars), with an S.E. of the estimate ranging from 5.88-6.66 years. Correlations were slightly higher in males than females. The equations obtained allowed estimation of age in a sample of 100 teeth from both sexes (not used for the regression) with an error of +/- 5 years in 81.4% of cases for male molars. The regression formulae for estimating age obtained from the recent sample were tested on a historical sample of 100 teeth from 100-year-old skeletons with an error of +/- 5 years in 70.3% of cases for male molars. This study illustrates the potential value of a little-known aging method which can be easily applied to estimate age in both living individuals and skeletal material of unknown age.

Age estimation from teeth using soft X-ray findings.

Soft X-ray photos of 68 premolars and 98 molars from 102 males and 64 females were taken to measure the length (mm) of the corona (CL) and the length of coronal pulp cavity (CPCL). Then the coronal index CI = CPCL x 100/CL after Ikeda et al. (1985) was computed for each tooth and regressed on the actual age of the individuals to obtain equations that allow estimation of age in unknown bodies and isolated teeth. The correlation coefficients ranged from -0.73 (female molars) to -0.89 (female premolars). No significant differences were observed in age estimation using sex-specific equations.