Multivariate assessments of activity-related skeletal changes: Interpreting Bell Beaker specialized male archery and social organization in Central Europe

Objectives

The Bell Beaker period witnessed the rise of individual inhumations with “wealthy” burial contexts containing archery-related grave goods, leading archaeologists to label the individuals in these tombs as “archers.” This study looks to (1) compare the skeletons from male “archer” burials with those from male “non-archer” burials—those not having archery-related grave goods—in order to assess a possible link between burial context and physical activity, and (2) apply a biomechanics profile to evaluate whether the individuals associated with these “archer” burials practiced specialized archer activity.

Materials and Methods

The corpus (males only) included 46 “archers” and 40 “non-archers” from Bell Beaker individual inhumations. Osteological data included measurements, scores of entheseal changes, and a diagnosis of certain pathologies. Data analyses involved visual observations, hypothesis tests, dimension reduction, and MANOVA, with approaches aimed at exploring the treatment of data missingness.

Results

Measurement data revealed no differences between the two groups. Evaluations of entheseal changes found that “non-archers” had consistently more instances of bone surface modifications than “archers.” Individual assessments of specialized archer occupation identified 11 possible specialized archers.

Discussion

These findings indicate a possible labor differentiation represented through the presence of a probably prestigious “archer” burial context. This suggests a link between grave good presence and labor, but not between a Bell Beaker archery occupation and an “archer” burial context. Data analyses support the application of biomechanics to osteological analyses in order to assess specialized activity on the skeleton.     

Functional plasticity of the human humerus: Shape,rigidity, and muscular entheses

The relationship between the mechanical loading undergone by a bone and its form has been widely assumed as a premise in studies aiming to reconstruct behavioral patterns from skeletal remains. Nevertheless, this relationship is complex due to the existence of many factors affecting bone structure and form, and further research combining structural and shape characteristics is needed. Using two‐block PLS, which is a test to analyze the covariance between two sets of variables, we aim to investigate the relationship between upper‐limb entheseal changes, cross‐sectional properties, and contour shape of the humeral diaphysis. Our results show that individuals with strongly marked entheseal changes have increased diaphyseal rigidities. Bending rigidities are mainly related to entheseal changes of muscles that cross the shoulder. Moreover, the entheseal changes of muscles that participate in the rotation of the arm are related to mediolaterally flatter and ventrodorsally broader humeral shapes in the mid‐proximal diaphysis. In turn, this diaphyseal shape is related to diaphyseal rigidity, especially to bending loadings. The shape of the diaphysis of the rest of the humerus does not covary either with rigidity or with entheseal changes. The results indicate that large muscular scars, such as those found in the mid‐proximal diaphyses, seem to be related to diaphyseal shape, whereas this relationship is not seen for areas with less direct influences of powerful muscles. Am J Phys Anthropol 150:609–617, 2013. © 2013 Wiley Periodicals, Inc.     

The influence of sex, age and heritability on human skeletal muscle carnosine content

The dipeptide carnosine is found in high concentrations in human skeletal muscle and shows large inter-individual differences. Sex and age are determining factors, however, systematic studies investigating the sex effects on muscle carnosine content throughout the human lifespan are lacking. Despite the large inter-individual variation, the intra-individual variation is limited. The question may be asked whether the carnosine content is a muscle characteristic which may be largely genetically determined. A total of 263 healthy male and female subjects of 9-83 years were divided into five different age groups: prepubertal children (PC), adolescents (A), young adults (YA), middle adults (MA) and elderly (E). We included 25 monozygotic and 22 dizygotic twin pairs among the entire study population to study the heritability. The carnosine content was measured non-invasively in the gastrocnemius medialis and soleus by proton magnetic resonance spectroscopy (1H-MRS). In boys, carnosine content was significantly higher (gastrocnemius 22.9%; soleus 44.6%) in A compared to PC, while it did not differ in girls. A decrease (~16%) was observed both in males and females from YA to MA. However, elderly did not have lower carnosine levels in comparison with MA. Higher correlations were found in monozygotic (r=0.86) compared to dizygotic (r=0.51) twins, in soleus muscle, but not in gastrocnemius. In conclusion, this study found an effect of puberty on muscle carnosine content in males, but not in females. Muscle carnosine decreased mainly during early adulthood and hardly from adulthood to elderly. High intra-twin correlations were observed, but muscle-dependent differences preclude clear conclusions toward heritability.     

Decline of tactile acuity in aging: a study of body site,blood flow,and lifetime habits of smoking and physical activity

Tactile acuity of 60 older subjects (≥?65 years) and 19 younger subjects (18–28 years) was assessed by two-point gap thresholds at the upper and lower surfaces of the forefinger, at the upper and lower surfaces of the feet, and at the volar surface of the forearm. The older subjects were assigned to one of four groups of 15 subjects each, depending on reported lifetime habits of physical activity and smoking: (1) active smokers, (2) active nonsmokers, (3) inactive smokers, and (4) inactive nonsmokers. Peripheral blood flow was assessed at the forefinger, foot, and forearm by means of laser-Doppler imaging and skin temperature recordings, under resting conditions and during and after a 5-min exposure to mild cooling (28°C). Consistent with previous studies, tactile acuity thresholds in the foot and finger averaged about 80% higher in the older subjects than in the younger subjects, but only about 22% higher in the forearm. Although the upper surface of the fingertip was more sensitive than the lower surface in both younger and older subjects, the age-related decline in tactile acuity was nearly identical on both sides of the finger and foot. The latter finding refutes the hypothesis that the larger effect of aging in the extremities results from greater physical wear and tear on the contact surfaces of the hands and feet. Self-reported lifetime histories of physical activity and smoking were not significantly associated with measures of cutaneous blood flow or tactile thresholds. Possible reasons for this lack of association are discussed, including the inherent limitations of testing only healthy older subjects, and the concept of “successful aging”.     

Proteasomal activity in skeletal muscle: A matter of assay design, muscle type, and age

The ubiquitin-proteasome system (UPS) is a major degradation system for regulatory and misfolded proteins. UPS function has been implicated to exert a central role in the pathogenesis of various human diseases. Because biochemical analyses are often hampered by the amount of available diseased tissue, we report on the establishment and validation of a luminescence-based proteasomal activity assay applicable to 5-mg quantities of skeletal muscle. We demonstrate that the specific proteasomal activity differs in individual muscle groups and decreases with aging. These findings warrant the use of appropriate controls and a careful interpretation of results in mammalian skeletal muscle pathologies.     

Hematocrit,age, and survival in a wild vertebrate population

Understanding trade‐offs in wild populations is difficult, but important if we are to understand the evolution of life histories and the impact of ecological variables upon them. Markers that reflect physiological state and predict future survival would be of considerable benefit to unraveling such trade‐offs and could provide insight into individual variation in senescence. However, currently used markers often yield inconsistent results. One underutilized measure is hematocrit, the proportion of blood comprising erythrocytes, which relates to the blood's oxygen‐carrying capacity and viscosity, and to individual endurance. Hematocrit has been shown to decline with age in cross‐sectional studies (which may be confounded by selective appearance/disappearance). However, few studies have tested whether hematocrit declines within individuals or whether low hematocrit impacts survival in wild taxa. Using longitudinal data from the Seychelles warbler (Acrocephalus sechellensis), we demonstrated that hematocrit increases with age in young individuals (<1.5 years) but decreases with age in older individuals (1.5–13 years). In breeders, hematocrit was higher in males than females and varied relative to breeding stage. High hematocrit was associated with lower survival in young individuals, but not older individuals. Thus, while we did not find support for hematocrit as a marker of senescence, high hematocrit is indicative of poor condition in younger individuals. Possible explanations are that these individuals were experiencing dehydration and/or high endurance demands prior to capture, which warrants further investigation. Our study demonstrates that hematocrit can be an informative metric for life‐history studies investigating trade‐offs between survival, longevity, and reproduction.     

Effect of age, sex, and smoking on serum catalase activity

In selected hospitalized patients (9294) with normal serum catalase activity, 7.58 per cent higher (p less than 0.001) serum catalase activity was detected in males than in females. With age, serum catalase activity decreased (slope-0.0683) in males, increased (slope 0.101) in females and did not change in all patients (slope 0.049). Cigarette smoking did not influence serum catalase activity (p greater than 0.05).     

The effects of sex hormones,prolactin, and chorionic gonadotropin on pineal electrical activity in guinea pigs

Microelectrophoretic application of sex hormones onto pineal cells in guinea pigs has shown different responses in pregnant females as compared to males. In pregnant females estrone caused excitation in 74% of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells. In contrast, in males estrone caused excitation of only 19% but inhibition of 37%. A smaller percentage of cells was inhibited by progesterone, while the predominant response to testosterone was excitation. These results suggest that the pineal gland may be under a feedback control.This work was supported by the Volkswagenwerk-Stiftung, Grant I/35472.Visiting scientist supported by grant from the Deutsche Forschungsgemeinschaft and the Royal Society.