Materials for phantoms for terahertz pulsed imaging

Phantoms are commonly used in medical imaging for quality assurance, calibration, research and teaching. They may include test patterns or simulations of organs, but in either case a tissue substitute medium is an important component of the phantom. The aim of this work was to identify materials suitable for use as tissue substitutes for the relatively new medical imaging modality terahertz pulsed imaging. Samples of different concentrations of the candidate materials TX151 and napthol green dye were prepared, and measurements made of the frequency-dependent absorption coefficient (0.5 to 1.5 THz) and refractive index (0.5 to 1.0 THz). These results were compared qualitatively with measurements made in a similar way on samples of excised human tissue (skin, adipose tissue and striated muscle). Both materials would be suitable for phantoms where the dominant mechanism to be simulated is absorption (similar to ∼100 cm(-1) at 1 THz) and where simulation of the strength of reflections from boundaries is not important; for example, test patterns for spatial resolution measurements. Only TX151 had a frequency-dependent refractive index close to that of tissue, and could therefore be used to simulate the layered structure of skin, the complexity of microvasculature or to investigate frequency-dependent interference effects that have been noted in terahertz images

New Mexico Youth Risk & Resiliency 2015 Survey Results Report: Housing Instability and Health

In 2015, for the first time, the NM-YRRS questionnaire included a question on homelessness, or housing status. The question mirrored the homelessness definition of the McKinney-Vento Act, which is used by the New Mexico Public Education Department to identify homeless students. For the purposes of this report, students identified as homeless will be referred to as students in unstable housing. Students living in unstable housing were at significantly increased risk for facing violence, using alcohol, tobacco, and other drugs, suicidal behaviors and other mental health issues and other serious challenges

New Mexico Youth Risk & Resiliency 2013 Survey Results Report: Tobacco Use and Related Behaviors

Te negative effects of tobacco use are well documented: cigarette smoking has been linked to cancer, heart disease, and chronic obstructive pulmonary disease (COPD). The earlier a person initiates smoking, the greater their risk for long-term health problems and nicotine addiction. The Centers for Disease Control and Prevention (CDC) estimates that 1 in 5 high school students currently uses some form of tobacco. NM-YRRS measures tobacco use, attitudes, and behaviors among New Mexico students in grades 6–12

New Mexico Youth Risk & Resiliency 2015 Survey Results Report: Alcohol Use and Related Behaviors.

Alcohol is the most commonly used and abused drug by youth in the United States. Youth who drink alcohol before age 15 are six times more likely to develop alcohol dependence or abuse later in life than those who begin drinking at age 21 or older. Binge drinking (5 or more drinks on a single occasion) accounts for about 90% of the alcohol consumed by youth 12–20 years of age in the United States. The New Mexico Youth Risk & Resiliency Survey (NM-YRRS) includes questions about alcohol use, access, attitudes, and behaviors as well as protective (resiliency) factors that can help reduce these risky behaviors

New Mexico Youth Risk & Resiliency 2015 Survey Results Report: Drug Use and Related Behaviors.

New Mexico Youth Risk & Resiliency 2015 Survey Results Report: Drug Use and Related Behaviors. Epidemiology and Response Division, New Mexico Department of Health, School and Family Support Bureau, New Mexico Public Education Department, and the University of New Mexico Prevention Research Center

New Mexico Youth Risk & Resiliency 2015 Survey Results Report: Tobacco Use and Related Behaviors

Tobacco use remains the leading cause of preventable disease in the US. Tobacco use and nicotine addiction typically begin during adolescence and young adulthood, and nicotine exposure during adolescence can lead to addiction, may harm brain development, and could lead to sustained tobacco use among youths. The New Mexico Youth Risk & Resiliency Survey includes questions about tobacco use and other risk behaviors as well as protective (resiliency) factors that can help reduce these risk behaviors

A comparison of single-cycle versus multiple-cycle proof testing strategies

An evaluation of single-cycle and multiple-cycle proof testing (MCPT) strategies for SSME components is described. Data for initial sizes and shapes of actual SSME hardware defects are analyzed statistically. Closed-form estimates of the J-integral for surface flaws are derived with a modified reference stress method. The results of load- and displacement-controlled stable crack growth tests on thin IN-718 plates with deep surface flaws are summarized. A J-resistance curve for the surface-cracked configuration is developed and compared with data from thick compact tension specimens. The potential for further crack growth during large unload/reload cycles is discussed, highlighting conflicting data in the literature. A simple model for ductile crack growth during MCPT based on the J-resistance curve is used to study the potential effects of key variables. The projected changes in the crack size distribution during MCPT depend on the interactions between several key parameters, including the number of proof cycles, the nature of the resistance curve, the initial crack size distribution, the component boundary conditions (load vs. displacement control), and the magnitude of the applied load or displacement. The relative advantages of single-cycle and multiple-cycle proof testing appear to be specific, therefore, to individual component geometry, material, and loading