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Forensic experts often have to assess injury and fatality risks in the context of violent blunt force trauma. Maximum striking velocities in one- and two-handed strikes with a rod-like implement can be of particular interest. Current literature lacks studies addressing this problem. The purpose of this study was therefore to measure and analyse maximum striking velocities in one-handed and two-handed strikes in female and male volunteers. We hypothesised higher striking velocities in two-handed strikes compared to one-handed strikes. Fifty volunteers performed one- and two-handed strikes from top to bottom using a steel rod of 65 cm length and 1000 g weight. A Qualisys™ Motion Analysis system registered displacements of reflecting markers fixed to the rod as well as to the volunteer's body. In one-handed strikes, the mean maximum striking velocity was 17.2 m/s in the female sample and 23.9 m/s in the male sample. Statistically not significantly different maximum striking velocities were found in two-handed strikes with mean values of 18.3 m/s in the female sample and 24.2 m/s in the male sample. Female and male volunteers also yielded similar mean maximum striking velocities in two-handed strikes comparing 'overhead' and 'overshoulder' striking techniques. In conclusion, the striking technique did not relevantly influence maximum striking velocities in our setup.

In blunt force trauma to the head caused by attacks with blunt instruments, contact forces can be estimated based on the conservation of momentum if impact velocities are known. The aims of this work were to measure maximum striking velocities and to examine the influence of rod parameters such as rod mass and length as well as volunteer parameters such as sex, age, body height, body mass, body mass index and the average amount of physical exercise. Steel rods with masses of 500, 1000 and 1500 g as well as lengths of 40, 65 and 90 cm were exemplarily tested as blunt instruments. Twenty-nine men and 22 women participated in this study. Each volunteer performed several vertical strikes with the steel rods onto a passive immobile target. Maximum striking velocities were measured by means of a Qualisys motion capture system using high-speed cameras and infrared light. Male volunteers achieved maximum striking velocities between 14.0 and 35.5 m/s whereas female volunteers achieved values between 10.4 and 28.3 m/s. Results show that maximum striking velocities increased with smaller rod masses and less consistently with higher rod lengths. Statistically significant influences were found in the volunteers' sex and average amount of physical exercise.

Background Respiratory tract infection is leading causes of death among patients infected with human immunodeficiency virus in Vietnam. Identification the agents caused RTIs is very important to give specific treatment and to reduce mortality rate among HIV/AIDS patients suffering from RTI. Methods We conducted a cross-sectional study of 170 HIV/AIDS patients with signs and symptoms (clinical manifestations and/or broncho aveolar lesions through X-ray chest film) of respiratory tract to indentify the common agents by analysing bronchoaveolarlavage (BAL). Results A total of 170 HIV/AIDS patients (138 male and 32 female) involved in the study and 170 BAL samples had been taken to identify the common agents caused RTIs. 148/170 (87.1%) patients had been diagnosed RTIs with following agents: Mycobacterium tuberculosis 79/148 (53.4%), PJP 12/148 (8.1%), bacteria 59/148 (39.9%), fungi 54/148 (36.5%) and CMV 2/148 (1.4%). 52/148 (35.1%) patients had been isolated 2 differential agents at a moment. Most patients have very low CD4+ count (80.4% ≤ 100cells/mm3; mean = 74.6; SD = 118.7; median = 22). The more common bacteria are: Pseudomonas (P.aeruginosa, P.putida, P.pneumotropica) 15/59 (25.4%), Streptococcus (S.pneumoniae, S.pyogene) 11/59 (18.6%), Acinobacter (Aci.baumani, Aci.juni, Aci.minimus) 6/59 (10.2%), E.coli 3/59 (5.1%) and S.aureus 3/59 (5.1%). Other include: H.influenza 2/59 and each following spp have 1: Achromobacter xylosoxidans, K.pneumoniae, Enterobacter clocae, Moraxella catarhalis, and Rhodococcus equi. Isolated fungal spp include: Candida albicans 32/54 (59.2%), Penicillium marneffei 14/54 (25.9%), Aspergilus spp 4 (7.4%), Candida spp 3/54 (5.6%) and Cryptococcus neoformans 1/54 (1.9%). The common complex infections are MTB-Fungi (16 patients), MTB-Bacteria (14 patients) and Bacteria-Fungi (11patients). Conclusion Mycobacterium tuberculosis, bacteria (P.aeruginosa, P.putida, P.pneumotropica, S.pneumoniae, S.pyogene, and Aci.baumani) and fungi (Candida albicans and Penicillium marneffei) are the more common in HIV/AIDS patients who have RTIs. Because of advanced immune depression, patients may have complex infections in a moment.