Strategic interactions: Games of the Ju|'hoan.

Three strategic games played by the Ju|'hoan-a board, a card, and a gesture game-complicate the rhetorics that suggest an evolutionary or psychological significance of play. They are mostly played by adults, although every individual adult does not necessarily engage in each game. The Ju|'hoan card and board game practices were transmitted through contact across large parts of Botswana and Namibia, while the gesture game n!àì has been known in other San communities. It suggests that the significance of strategic games is more likely found in its potential for social interaction (i.e., allowing to overcome cultural divides) than in evolution and psychology. Within the anthropological literature, strategy games were thought to be absent in egalitarian societies, such as that of the Ju|'hoan. Here, the roles of power, competition, and winning were thought to be disruptive and unwanted. A closer examination of the details behind the Ju|'hoan games shows that not only were strategy games adopted and adapted from neighboring societies but that the game of n!àì was developed by the Ju|'hoan into a competitive one. The evolutionary or psychological significance of play is informed by studies on individual play, children's play, and games with informal rules. When considering strategic games throughout history, it is their role of facilitator rather than the playing practice itself that makes games relevant across languages, cultural divides, and sociopolitical boundaries.

Indian Ocean crossroads: human genetic origin and population structure in the Maldives.

The Maldives are an 850 km-long string of atolls located centrally in the northern Indian Ocean basin. Because of this geographic situation, the present-day Maldivian population has potential for uncovering genetic signatures of historic migration events in the region. We therefore studied autosomal DNA-, mitochondrial DNA-, and Y-chromosomal DNA markers in a representative sample of 141 unrelated Maldivians, with 119 from six major settlements. We found a total of 63 different mtDNA haplotypes that could be allocated to 29 mtDNA haplogroups, mostly within the M, R, and U clades. We found 66 different Y-STR haplotypes in 10 Y-chromosome haplogroups, predominantly H1, J2, L, R1a1a, and R2. Parental admixture analysis for mtDNA- and Y-haplogroup data indicates a strong genetic link between the Maldive Islands and mainland South Asia, and excludes significant gene flow from Southeast Asia. Paternal admixture from West Asia is detected, but cannot be distinguished from admixture from South Asia. Maternal admixture from West Asia is excluded. Within the Maldives, we find a subtle genetic substructure in all marker systems that is not directly related to geographic distance or linguistic dialect. We found reduced Y-STR diversity and reduced male-mediated gene flow between atolls, suggesting independent male founder effects for each atoll. Detected reduced female-mediated gene flow between atolls confirms a Maldives-specific history of matrilocality. In conclusion, our new genetic data agree with the commonly reported Maldivian ancestry in South Asia, but furthermore suggest multiple, independent immigration events and asymmetrical migration of females and males across the archipelago.

Go-around accidents and general aviation safety.

INTRODUCTION: Changes in General Aviation (GA) accident rates, specifically in the go-around phase, are examined by comparing the number of accidents, the proportion of fatal accidents, and the proportion of certain causes of accidents over time. METHODS: Two sets of accidents from 2000 to 2004 and from 2013 to 2017 were extracted from the National Transportation Safety Board (NTSB) online database. RESULTS: Although the total number of GA accidents per landing significantly decreased over time, the proportion of fatal accidents in the go-around phase increased. Fatalities most often occurred in instrument meteorological conditions. CONCLUSION: Advances in technology and training show improvements in GA accident rates, but not for accidents in the go-around phase. PRACTICAL APPLICATIONS: Scenario-based learning is recommended to include specific instruction concerning the timing of go-around procedures in unstable flights.

Gyroplane accidents 1985-2005: epidemiological analysis and pilot factors in 223 events.

INTRODUCTION: Gyroplanes (autogyros) are regarded as a relatively safe and stable type of general-aviation aircraft. The U.S. Federal Aviation Administration categorizes them as sport pilot/light sport aircraft, and reports of gyroplane accidents are included in a publicly available database. We hypothesized that issues related to pilot experience and aircraft maintenance would affect the severity of accidents as indicated by aircraft damage and fatalities. METHODS: A search of the National Transportation Safety Board database for the period 1985-2005 yielded 223 reports of gyroplane accidents. Information from those reports was compiled and cross-referenced with pilot performance breakdowns and contextual information. The data was then analyzed using the Human Factors Analysis and Classification System. RESULTS: There was a strong effect of pilot experience on crash outcomes; compared to more experienced pilots, crashes involving pilots with less than 40 flight hours in the same make/model gyroplane were five times more likely to involve loss of control, twice as likely to destroy the aircraft, and four times more likely to involve fatalities. On the other hand, crashes involving pilots with more than 40 make/model hours were more likely to be related to perception-based performance breakdown. Maintenance issues were not found to play a significant role in this sample of crashes. CONCLUSION: The results support the hypothesis that pilot experience is a significant predictor of accident fatality in gyroplanes. Training that is adapted to the experience level of pilots as implemented in new FAA regulations for sport pilot and light sport aircraft (2004) may help to reduce the frequency and seriousness of gyroplane accidents.

Emergency Highway Landings in General Aviation and the Possible Role of Media Reports.

BACKGROUND: To examine the causes and factors of airplane landings on highways and the dangers to occupants of vehicles on the ground. METHODS: The U.S. National Transportation Safety Board online database provided 133 accidents involving a highway landing dating from 2000 to 2013. Supplemental information was sought in online media archives, which reported on 53 of these accidents. Collisions with highway-related objects, other options for landing, and witness accounts were added categories extracted from the narrative statements and media reports. RESULTS: Highway landings occur mostly due to mechanical failures, ineffective preflight or in-flight planning, and fuel exhaustion, in addition to a lack of alternate landing options for a pilot of a fixed-wing aircraft. Most of the landings (N = 108) lead to minor or no injuries at all. A significant proportion of 7 out of 19 collisions with powerlines resulted in a fatality, as opposed to other types of accidents. Collisions with motor vehicles (N = 29) caused minor (N = 23) and serious (N = 2) injuries to people on the ground. Main online media archives covered less than half of all accidents (39.8%). DISCUSSION: While highway landings are not a recommended landing alternative, mitigation strategies should include a focus on avoiding powerlines and vehicles on the ground. Unfortunately, online media archives are not yet a consistent source of information for general aviation accidents.Holzman E, de Voogt A. Emergency highway landings in general aviation and the possible role of media reports. Aerosp Med Hum Perform. 2017; 88(5):497-499.