The traumatic potential of a projectile shot from a sling.

Herein, we analyze the energy parameters of stones of various weights and shapes shot from a sling and based on this data evaluate its traumatic potential. Four police officers proficient in the use of a sling participated in the trials. The following projectile types, shot using an overhead technique at a target 100m away were: round steel balls of different sizes and weights (24mm, 57g; 32mm, 135g; 38mm, 227g); different shaped stones weighing 100-150g and 150-200g and a golf ball (47g). Our data indicated that projectiles shot from unconventional weapons such as a sling, have serious traumatic potential for unprotected individuals and can cause blunt trauma of moderate to critical severity such as fractures of the trunk, limb, and facial skull bone, depending on the weight and shape of the projectile and the distance from the source of danger. Asymmetrically shaped projectiles weighing more than 100g were the most dangerous. Projectiles weighing more than 100g can cause bone fractures of the trunk and limbs at distances of up to 60m from the target and may cause serious head injuries to an unprotected person (Abbreviated Injury Scale 4-5) at distances up to 200m from the target. Due to the traumatic potential of projectiles shot from a sling, the police must wear full riot gear and keep at a distance of at least 60m from the source of danger in order to avoid serious injury. Furthermore, given the potential for serious head injuries, wearing a helmet with a visor is mandatory at distances up to 200m from the source of danger.

Adaptive Changes in Basal Metabolic Rate in Humans in Different Eco-Geographical Areas.

Our aim was to establish whether the human basal metabolic rate (BMR) shifts towards the reduction of vital functions as an adaptation response to extreme environmental conditions. Data was collected in arid and Extreme North zones. The arid zone samples included Bedouins living in the Sinai Peninsula in Egypt, Turkmen students, the Pedagogical University of Chardzhou, Turkmenistan born Russians and Russian soldiers. Soldiers were divided into 3 groups according to the length of their tour of duty in the area: 1st group: up to six months, 2nd group: up to 2 years and the 3rd group: 3-5 years. The Extreme North samples comprised Chukchi natives, 1st generation Russian immigrants born in the area and 3 groups of soldiers comparable to the soldiers from Turkmenistan. BMR values of the new recruits had the highest values of total and relative BMR (1769 ± 16 and 28.3 ± 0.6, correspondingly). The total and relative BMR tended to decrease within a longer adaptation period. The BMR values of officers who served >3 years in Turkmenistan were very similar to the Turkmenistan born Russians (1730 ± 14 vs. 1726 ± 18 and 26.5 ± 0.6 vs. 27.3 ± 0.7, correspondingly). Similarly, in Chukotka, the highest relative BMR was found in the new recruits, serving up to 6 months (28.1 ± 0.7) and was significantly (p < 0.05) lower in the Russians serving in Chukotka over 1.5 years (27.1 ± 0.3). The BMR was virtually similar in Russian officers serving > 3 years, compared to the middle-aged Chukchi or Chukotka-born Russians (25.8 ± 0.5 vs. 25.6 ± 0.5 and 25.5 ± 0.6, correspondingly). The BMR parameters demonstrated a stronger association with body weight than with age. In extreme environmental conditions, migrant populations showed a decrease in BMR, thus reducing its vital functions. The BMR reduction effect with the adequate adaptive transformation is likely to be the key strategy for developing programs to facilitate human and animal adaptation to extreme factors. This process is aimed at preserving the optimum energy balance and homeostasis while minimizing stress on the body's vital functions.

Morpho-physiological features of human populations in the context of climatic--geographical conditions.

This paper is based on the data obtained in the course of population studies conducted in 33 geographical regions of the former USSR territory by the faculty of the Anuchin Research Institute and Museum of Anthropology, Lomonosov Moscow State University, between 1961 and 1991. The data resulting from study of 4386 male and 4626 female subjects aged 17 to 99 include head and body morphology, bone mineral density, blood oxygen saturation and blood biochemistry. We aimed at studying the link between the traits of a population and the climatic conditions of the area inhabited by this population. Individual characteristics of the subjects were normalized by age and sex, and factor analysis was used to reduce the number of cross-correlating features. As a result, several integral characteristics (factors) were identified: five body morphology-related factors, two head morphology-related factors, one bone mineral density-related factor, one blood oxygen saturation-related factor and three blood biochemistry-related factors. These factors explained 79.3%, 78.38%, 63.51%, 74.4% and 66.77% of the trait groups' variability, respectively. The correlation analysis between these factors and climatic indicators demonstrated that chest dimensions were the least tolerant to the climatic conditions among the morphological characteristics studied. Hemoglobin-protein ratios, as well as the factor that includes total cholesterol, were the most climate-dependent among the biochemical parameters. As far as our data show, blood serum oxygen saturation--the key factor determining the performance of the cardiovascular and respiratory systems--is also climate-dependent.

Middle ear pathology in ancient and modern populations: incudal osteoma.

CONCLUSIONS: Osteomas of the incus were found in surprisingly high numbers in ancient and modern populations. The coexistence of osteoma formation and unique vascularization on the medial surface of the incus alludes to a relationship between the two findings. OBJECTIVE: Osteomas involving the middle ear ossicles are rare. The aim of this study was to compare the incudal pathology of ancient and recent periods using the recent literature. MATERIAL AND METHODS: Pathologies encountered in 1170 human incudes belonging to different populations from ancient and recent periods were studied. Most of the ossicles were found in the middle ear of dry skulls or during dissection. The observations were done with a binocular microscope and a Nikon Profile Projector. RESULTS: A total of 47 incudes (4.01%) presented with a variety of pathologies, osteomas being found in 19 cases (1.62%). The osteomas were noted only on the medial surface of the incus. Other findings, including prominent erosions, multiple nutrient foramina and pitting, were also found on the medial side of the incus. The incidence of osteoma was found to be more common in ancient populations (1.88%) and most prevalent among Bedouins (4.55%).