OBJECTIVE To determine gun storage practices in gun-owning households with children. DESIGN National random digit-dial telephone survey of 2521 households conducted in March 1999 through July 1999. This study uses a subsample of 434 households with children <18 years old in which a respondent reported either: 1) personally owning a gun, or 2) living in a gun-owning household but not owning a ...

the track stiffness experienced by a train will vary along the track. sometimes the stiffness variation may be very large within a short distance. one example is when an unsupported sleeper is hanging in the rail. track stiffness is then, locally at that sleeper, very low. at insulated joints the bending stiffness of the rail has a discontinuity implying a discontinuity also of the track stiffn...

One rare and interesting species collected from Seorak-san, Inje-gun; Yeonyeop-san, Hongcheon-gun; Daeam-san, Yanggu-gun, Gangwon-do; Pocheon-gun, Gyeonggi-do; Songni-san, Boeun-gun; Joryeong-san, Goesan-gun, Chungcheongbuk-do and Sobaeksan, Yeongju-si, Gyeongsangbuk-do is described and illustrated in detail. The species "Protodaedalea hispida Imazeki" and genus "Protodaedalea Iamzeki" has not ...

Gun violence is a leading cause of premature deaths in the United States. Evidence has linked higher levels of firearm ownership to an increased risk for violent crimes perpetrated with a firearm. Given that connection, the goal of this study is to use mathematical modeling techniques to better understand how different social conditions may impact gun-ownership rate. To accomplish that goal, we...

Rail inspection is an important task in railway maintenance. The speed and loads of trains have been increasing greatly in recent years, and these factors inevitably raise the risk of producing rail defects. Mainly the discrete surface defects impact the riding quality and safety of a railway system. However, it is a challenge to inspect such defects in a vision system because of illumination i...

A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, se...

Rail joints have a shorter service life than most other railway track components. The discontinuity between rail ends turns the rail joint into a weak spot, and consequently, into a track component demanding more frequent maintenance measures, which result in high maintenance costs. Moreover, difficulties are often found when assessing the damage condition of rail joints since damage conditions...

OBJECTIVE Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. METHOD The most recent data from the American National Election Study, a large representative US sample, ...

This paper provides new estimates of the effect of household gun prevalence on homicide rates, and infers the marginal external cost of handgun ownership. The estimates utilize a superior proxy for gun prevalence, the percentage of suicides committed with a gun, which we validate. Using countyand state-level panels for 20 years, we estimate the elasticity of homicide with respect to gun prevale...

This paper examines the merit of two propositions at the center of the debate on gun control in the aftermath of mass shootings in the United States: (1) gun violence and mass shootings are a cultural artifact (gun enthusiast perspective); (2) gun violence and mass shootings are more prevalent due to lax regulations (pro-gun control perspective). To evaluate the value of each proposition, the s...