Connection Between Time- and Frequency-Domain Three-Dimensional Inverse Problems for the Schrödinger Equation

The use of inverse scattering methods in electromagnetic remote sensing, seismic exploration and ultrasonic imaging is rapidly expanding. For these cases which involve classical wave equations with variable velocity,1 no exact inversion methods exists for general three-dimensional (3d) scatterers. However, exact inversion methods (for example, those based on the Born series2 and the Newton-Marchenko equation2) do exist for the 3d Schrödinger equation. In this paper, these inversion methods for Schrödinger’s equation will be rewritten in a form which brings out certain analogies with classical wave equations. It is hoped these analogies will eventually contribute to a common exact inversion method for both types of equations

The Case for Enhanced Data Collection of Gun Type

Background: National surveillance systems have differentiated long guns into rifles and shotguns but fail to do so for handgun type. We sought to determine whether specific gun type data could be collected and whether knowledge of specific gun types (rifle, shotgun, pistol, revolver) could be used to distinguish gun homicide victims with respect to important injury parameters such as number of wounds. Methods: Data on gun fatalities over a 5-year period in three communities were abstracted from medical examiner/coroner, police, and crime laboratory records. Results: Gun type was obtained for 92% of 490 guns linked to 405 gun homicides. Handguns were associated with more wounds per gun than long guns (p = 0.001) and more entry wounds per gun than long guns (p = 0.002). Among handguns, pistols were associated with more wounds per gun (p \u3c 0.001) and entry wounds per gun (p = 0.001) than revolvers. These same associations were not found among specific long gun types (i.e., rifles and shotguns). Conclusion: Our findings demonstrate that information about gun type can be obtained and that significant differences exist in wounds per gun between long guns and handguns and between pistols and revolvers. Classification of long guns into rifles and shotguns and handguns into pistols and revolvers should be included in local, regional, and national data collection systems

A Perturbation Method for Inverse Scattering in Three-Dimensions Based on the Exact Inverse Scattering Equations

The detection and characterization of macroscopic flaws, such as cracks in solids are fundamental goals of nondestructive evaluation. Many inspection methods use scattered electromagnetic or ultrasonic waves. These methods rely explicitly on the development of inverse scattering theory. This theory seeks to determine the geometrical and material properties of flaws from scattering data

Recruitment of Community-Residing Youth Into Studies on Aggression

Recruitment of community-based youth into studies is challenging. We examined access issues, minority status, and personal costs of participation for a study of children with aggressive behaviors, designed to identify which ones are at risk for future violent behaviors, to identify protective factors, and to test interventions to reduce aggression. Of 1,038 contacts, 112 declined, 239 could not be re-contacted, and 124 were ineligible. Three hundred and fifty of 563 scheduled child-parent dyads completed intake assessment. Most were recruited through targeted mailings (33%) and community flyers (22%), 12% through regional news advertisement, 8% by Craigslist, and 5% through healthcare providers/clinics. Factors contributing to enrollment rates by zip code showed the percentage of Black residents per zip code and targeted mailings positively contributed (Beta = .200 & .419, respectively) and estimated transit travel time negatively contributed (Beta =.299) to enrollment rates (R2 = 0.562). Targeted mailings proved to be the most efficient strategy in successful recruitment

Effective Trauma Center Partnerships to Address Firearm Injury: A New Paradigm

Background: Firearm violence is the second leading cause of injury-related death. This study examined the use of local trauma centers as lead organizations in their communities to address firearm injury. Methods: Three trauma centers in cities with populations less than 100,000 were linked with a university-based firearm injury research center. A trauma surgeon director and coordinator partnered with communities, recruited and directed advisory boards, established a local firearm injury surveillance system, and informed communities using community-specific profiles. Primary process and outcome measures included completeness of data, development of community-specific profiles, number of data-driven consumer media pieces, number of meetings to inform policy makers, and an analysis of problems encountered. Results: Local trauma centers in smaller communities implemented a firearm injury surveillance system, produced community-specific injury profiles, and engaged community leaders and policy makers to address firearm injury. Community-specific profiles demonstrated consistent firearm suicide rates (6.58–6.82 per 100,000) but variation in firearm homicide rates (1.08–12.5 per 100,000) across sites. There were 63 data-driven media pieces and 18 forums to inform community leaders and policy makers. Completeness of data elements ranged from 57.1% to 100%. Problems experienced were disconnected data sources, multiple data owners, potential for political fallout, limited trauma center data, skills sets of medical professionals, and sustainability. Conclusion: Trauma centers, when provided resources and support, with the model described, can function as lead organizations in partnering with the community to acquire and use community-specific data for local firearm injury prevention

Mapping the epithelial-cell-binding domain of the Aggregatibacter actinomycetemcomitans autotransporter adhesin Aae

The Gram-negative periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) binds selectively to buccal epithelial cells (BECs) of human and Old World primates by means of the outer-membrane autotransporter protein Aae. We speculated that the exposed N-terminal portion of the passenger domain of Aae would mediate binding to BECs. By using a series of plasmids that express full-length or truncated Aae proteins in Escherichia coli, we found that the BEC-binding domain of Aae was located in the N-terminal surface-exposed region of the protein, specifically in the region spanning amino acids 201–284 just upstream of the repeat region within the passenger domain. Peptides corresponding to amino acids 201–221, 222–238 and 201–240 were synthesized and tested for their ability to reduce Aae-mediated binding to BECs based on results obtained with truncated Aae proteins expressed in E. coli. BEC-binding of E. coli expressing Aae was reduced by as much as 50 % by pre-treatment of BECs with a 40-mer peptide (201–240; P40). Aae was also shown to mediate binding to cultured human epithelial keratinocytes (TW2.6), OBA9 and TERT, and endothelial (HUVEC) cells. Pre-treatment of epithelial cells with P40 resulted in a dose-dependent reduction in binding and reduced the binding of both full-length and truncated Aae proteins expressed in E. coli, as well as Aae expressed in Aa. Fluorescently labelled P40 peptides reacted in a dose-dependent manner with BEC receptors. We propose that these proof-of-principle experiments demonstrate that peptides can be designed to interfere with Aa binding mediated by host-cell receptors specific for Aae adhesins