Discover the most talked about and latest scientific content & concepts.

Concept: Cannon


In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data.

Concepts: Scientific method, Epidemiology, Statistics, Mathematics, Firearm, Gun, Cannon, Firearms


Gun theft is an important source of guns used by criminals. Yet no empirical work has focused on the characteristics of gun owners that distinguish those who have had their guns stolen from those who have not. In this study, we examine the demographics and behavioral characteristics of gun owners who report having had a gun stolen.

Concepts: Gun, Cannon, Howitzer


Medieval European urbanization presents a line of continuity between earlier cities and modern European urban systems. Yet, many of the spatial, political and economic features of medieval European cities were particular to the Middle Ages, and subsequently changed over the Early Modern Period and Industrial Revolution. There is a long tradition of demographic studies estimating the population sizes of medieval European cities, and comparative analyses of these data have shed much light on the long-term evolution of urban systems. However, the next step-to systematically relate the population size of these cities to their spatial and socioeconomic characteristics-has seldom been taken. This raises a series of interesting questions, as both modern and ancient cities have been observed to obey area-population relationships predicted by settlement scaling theory. To address these questions, we analyze a new dataset for the settled area and population of 173 European cities from the early fourteenth century to determine the relationship between population and settled area. To interpret this data, we develop two related models that lead to differing predictions regarding the quantitative form of the population-area relationship, depending on the level of social mixing present in these cities. Our empirical estimates of model parameters show a strong densification of cities with city population size, consistent with patterns in contemporary cities. Although social life in medieval Europe was orchestrated by hierarchical institutions (e.g., guilds, church, municipal organizations), our results show no statistically significant influence of these institutions on agglomeration effects. The similarities between the empirical patterns of settlement relating area to population observed here support the hypothesis that cities throughout history share common principles of organization that self-consistently relate their socioeconomic networks to structured urban spaces.

Concepts: Scientific method, Middle Ages, Europe, Italy, Renaissance, Dark Ages, Age of Discovery, Cannon


Using previous research, we examined the impact of 4 handgun laws (waiting periods, universal background checks, gun locks, and open carrying regulations) on suicide rates.

Concepts: Regulation, Suicide, Firearm, Gun, Cannon, Handgun


Intimate partner homicide (IPH) is a critical public health and safety issue in the USA. In this study, we determine the prevalence and correlates of perpetrator suicide and additional homicides following intimate partner homicide (IPH) in a large, diverse state with high quality data. We extract IPHs from the North Carolina Violent Death Reporting System for 2004-2013 and identify suicides and other homicides that were part of the same incidents. We analyze the likelihood (in odds ration form) of perpetrator suicide and additional homicides using logistic regression analysis. Almost all IPH-suicide cases were by men with guns (86.6%). Almost one-half of IPHs committed by men with guns ended with suicide. Male-perpetrated IPH incidents averaged 1.58 deaths if a gun was used, and 1.14 deaths otherwise. It is well-known that gun access increases the chance that a violent domestic relationship will end in death. The current findings demonstrate that gun IPH is often coupled with additional killings. As suicidal batterers will not be deterred from IPH by threat of punishment, the results underline the importance of preemption by limiting batterers' access to guns.

Concepts: Regression analysis, Logistic regression, Death, Suicide, Homicide, Gun, Cannon, Nelson Erazo


Populations from two medieval sites in Central Poland, Stary Brześć Kujawski-4 (SBK-4) and Gruczno, represented high level of lactase persistence (LP) as followed by the LCT-13910*T allele’s presence (0.86 and 0.82, respectively). It was twice as high as in contemporaneous Cedynia (0.4) and Śródka (0.43), both located outside the region, higher than in modern inhabitants of Poland (0.51) and almost as high as in modern Swedish population (0.9). In an attempt to explain the observed differences its frequency changes in time were followed between the Middle Neolithic and the Late Middle Ages in successive dairying populations on a relatively small area (radius ∼60km) containing the two sites. The introduction of the T allele to Kuyavia 7.4 Ka BP by dairying LBK people is not likely, as suggested by the obtained data. It has not been found in any of Neolithic samples dated between 6.3 and 4.5 Ka BP. The identified frequency profile indicates that both the introduction and the beginning of selection could have taken place approx. 4 millennia after first LBK people arrived in the region, shifting the value of LP frequency from 0 to more than 0.8 during less than 130 generations. We hypothesize that the selection process of the T allele was rather rapid, starting just after its introduction into already milking populations and operated via high rates of fertility and mortality on children after weaning through life-threatening conditions, favoring lactose-tolerant individuals. Facing the lack of the T allele in people living on two great European Neolithization routes, the Danubian and Mediterranean ones, and based on its high frequency in northern Iberia, its presence in Scandinavia and estimated occurrence in Central Poland, we propose an alternative Northern Route of its spreading as very likely. None of the successfully identified nuclear alleles turned out to be deltaF508 CFTR.

Concepts: Middle Ages, Europe, Black Death, Neolithic, Renaissance, Cannon, Serfdom


All people share a need for safety. Yet, people’s pursuit of safety can conflict when it comes to guns, where some people perceive guns as a means to safety and others perceive guns as a threat to safety. We examined this conflict on a United States college campus that prohibits guns. We distinguished between people (N = 11,390) who (a) own a gun for protection, (b) own a gun exclusively for reasons other than protection (e.g., collecting, sports), and © do not own a gun. Protection owners felt less safe on campus, supported allowing guns on campus, and reported that they and others would feel safer and that gun violence would decrease if they carried a gun on campus. Non-owners and non-protection owners felt the reverse. The findings suggest that protection concerns, rather than gun-ownership per se, account for diverging perceptions and attitudes about guns and gun control.

Concepts: Psychology, Firearm, Weapon, Gun, Cannon, Howitzer


Mass public shootings are typically followed by a spike in gun sales as well as calls for stricter gun control laws. What remains unclear is whether the spike in gun sales is motivated by increased threat perceptions or by concerns about gun control, or whether the sales are mainly driven by non-owners purchasing guns or gun owners adding to their collection. Two surveys of gun owners and non-owners, conducted immediately before and after the Orlando shooting, allowed us to assess its impact on threat perceptions and on gun-purchasing intentions. Although there was a minor impact on threat perceptions of non-owners, neither group reported any increased gun-purchasing intentions or an increased need of a gun for protection and self-defense. We suggest that these responses are representative for the majority of Americans and, therefore, people who are influenced by mass shootings to buy guns are probably an atypical minority.

Concepts: United States, Firearm, Weapon, Gun, Cannon, Firearms, Gun politics in the United States, Howitzer


One way that guns get into the wrong hands is via gun sales without a background check. While the large majority of Americans support laws requiring universal background checks, no prior study has assessed whether Americans think it is acceptable behaviour to sell a gun to a stranger without a background check, whether or not there is a law against it.

Concepts: Law, Sales, Law of the United States, Gun, Cannon, Identity theft, Selling, Howitzer


Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring.

Concepts: Wound, Pelvis, Acetabulum, Pubis, Cannon, Superior pubic ramus, Rifling, Breech-loading weapon