External ballistics of Pleistocene hand-thrown spears: experimental performance data and implications for human evolution

The appearance of weaponry - technology designed to kill - is a critical but poorly established threshold in human evolution. It is an important behavioural marker representing evolutionary changes in ecology, cognition, language and social behaviours. While the earliest weapons are often considered to be hand-held and consequently short-ranged, the subsequent appearance of distance weapons is a crucial development. Projectiles are seen as an improvement over contact weapons, and are considered by some to have originated only with our own species in the Middle Stone Age and Upper Palaeolithic. Despite the importance of distance weapons in the emergence of full behavioral modernity, systematic experimentation using trained throwers to evaluate the ballistics of thrown spears during fight and at impact is lacking. This paper addresses this by presenting results from a trial of trained javelin athletes, providing new estimates for key performance parameters. Overlaps in distances and impact energies between hand-thrown spears and spearthrowers are evidenced, and skill emerges as a signifcant factor in successful use. The results show that distance hunting was likely within the repertoire of hunting strategies of Neanderthals, and the resulting behavioural flexibility closely mirrors that of our own specie

C-reactive protein levels: a prognostic marker for patients with head and neck cancer?

BACKGROUND: Recent advances in understanding complex tumor interactions have led to the discovery of an association between inflammation and cancer, in particular for colon and lung cancer, but only a very few have dealt with oral cancer. Therefore, the aim of the current study was to investigate the significance of preoperative C-reactive protein (CRP) levels as a parameter for development of lymph node metastases or recurrence. MATERIALS AND METHODS: In 278 patients with oral cancer, preoperative CRP levels were compared with development of recurrence and metastasis. RESULTS: In 27 patients from the normal CRP group, and in 21 patients from the elevated CRP group, local recurrence was observed. Concerning lymph node metastases, 37 patients were in the normal group and 9 patients in the elevated CRP group. No significant correlation could be found between elevated CRP levels and metastasis (p = 0.468) or recurrence (p = 0.137). CONCLUSION: Our findings do not appear to support a correlation between preoperative CRP levels and development of recurrence or metastases. In further studies, CRP levels in precancerous lesions and in Human Papilloma Virus (HPV) positive patients with oral squamous cell carcinoma (SCC) should be studied

Validity of the 3D VECTRA photogrammetric surface imaging system for cranio-maxillofacial anthropometric measurements

PURPOSE: The use of three-dimensional (3D) photography for anthropometric measurements is of increasing interest, especially in the cranio-maxillofacial field. Before standard implementation, accurate determination of the precision and accuracy of each system is mandatory. METHODS: A mannequin head was labelled with 52 landmarks, and 28 three-dimensional images were taken using a commercially available five-pod 3D photosystem (3D VECTRA; Canfield, Fairfield, NJ) in different head positions. Distances between the landmarks were measured manually using a conventional calliper and compared with the digitally calculated distances acquired from labelling by two independent observers. The experimental set-up accounted for clinical circumstances by varying the positioning (vertical, horizontal, sagittal) of the phantom. RESULTS: In the entire calliper measurement data set (n = 410), a significant difference (p = 0.02) between the directly measured and corresponding virtually calculated distances was found. The mean aberration between both modalities covering all data was 7.96 mm. No differences (p = 0.94) between the two groups were found using a cut-off of 10 % (leaving n = 369 distances) due to considerable errors in direct measurements and the necessary manual data translation. The mean diversity of both measurement modalities after cut-off was 1.33 mm (maximum, 6.70 mm). Inter-observer analysis of all 1,326 distances showed no difference (p = 0.99; maximal difference, 0.58 mm) in the digital measurements. CONCLUSION: The precision and accuracy of this five-pod 3D photosystem suggests its suitability for clinical applications, particularly anthropometric studies. Three-hundred-and-sixty degree surface-contour mapping of the craniofacial region within milliseconds is particularly useful in paediatric patients. Proper patient positioning is essential for high-quality imaging