Identification of barriers and beliefs influencing engagement by adult and teen Mexican-Americans in oral health behaviors

OBJECTIVE: To identify barriers and beliefs influencing oral health and dental care-seeking among Mexican-Americans. RESEARCH DESIGN: Interviews and Likert-scale survey questions were utilized to explore urgent and preventive dental care-seeking, oral hygiene habits and lifestyle practices. Thirty-three interviews were conducted with 16 adults (ages 33-52), and 17 adolescents (ages 14-19). RESULTS: Teens identified the same main barriers to accessing dental care as adults: high cost, financial limitations and lack of insurance. Most Mexican-Americans agreed with the belief that everyone will need urgent dental treatment and the majority believed that going to a dentist in private practice instead of the Emergency Room was important. Although adults recognized the importance of preventive dental care, half reported being unlikely to seek such care while half of teens reported that they were likely to do so. Adults reported relying equally on themselves and on peers to make dental care decisions, while teens mostly depended on others to make decisions about urgent and preventive care. Virtually all respondents believed regular brushing to be important and many flossing too. A major barrier to flossing was being unsure of the proper technique. Another barrier to better oral health was not having seen messages encouraging changes in lifestyle. CONCLUSIONS: This study found that Mexican-American teens and adults may experience oral health similarly. Teens do not have more positive oral health beliefs and encounter mostly the same barriers to care as adults

The characterization of Vicker`s microhardness indentations and pile-up profiles as a strain-hardening microprobe

Microhardness measurements have long been used to examine strength properties and changes in strength properties in metals, for example, as induced by irradiation. Microhardness affords a relatively simple test that can be applied to very small volumes of material. Microhardness is nominally related to the flow stress of the material at a fixed level of plastic strain. Further, the geometry of the pile-up of material around the indentation is related to the strain-hardening behavior of a material; steeper pile-ups correspond to smaller strain-hardening rates. In this study the relationship between pile-up profiles and strain hardening is examined using both experimental and analytical methods. Vickers microhardness tests have been performed on a variety of metal alloys including low alloy, high Cr and austenitic stainless steels. The pile-up topology around the indentations has been quantified using confocal microscopy techniques. In addition, the indentation and pile-up geometry has been simulated using finite element method techniques. These results have been used to develop an improved quantification of the relationship between the pile-up geometry and the strain-hardening constitutive behavior of the test material

Atom probe characterisation of segregation driven Cu and Mn-Ni-Si co-precipitation in neutron irradiated T91 tempered-martensitic steel

The T91 grade and similar 9Cr tempered-martensitic steels (also known as ferritic-martensitic) are leading candidate structural alloys for fast fission nuclear and fusion power reactors. At low temperatures (300 to 400 $^\circ$C) neutron irradiation hardens and embrittles these steels, therefore it is important to investigate the origin of this mode of life limiting property degradation. T91 steel specimens were separately neutron irradiated to 2.14 dpa at 327 $^\circ$C and 8.82 dpa at 377 $^\circ$C in the Idaho National Laboratory Advanced Test Reactor. Atom probe tomography was used to investigate the segregation driven formation of Mn-Ni-Si-rich (MNSPs) and Cu-rich (CRP) co-precipitates. The precipitates increase in size and, slightly, in volume fraction at the higher irradiation temperature and dose, while their corresponding compositions were very similar, falling near the Si(Mn,Ni) phase field in the Mn-Ni-Si projection of the Fe-based quaternary phase diagram. While the structure of the precipitates has not been characterized, this composition range is distinctly different than that of the typically cited G-phase. The precipitates are composed of CRP with MNSP appendages. Such features are often observed in neutron irradiated reactor pressure vessel (RPV) steels. However, the Si, Ni, Mn, P and Cu solutes concentrations are lower in the T91 than in typical RPV steels. Thus, in T91 precipitation primarily takes place in solute segregated regions of line and loop dislocations. These results are consistent with the model for radiation induced segregation driven precipitation of MNSPs proposed by Ke et al. Cr-rich alpha prime ($\alpha$') phase formation was not observed.Comment: Pre-print (not peer reviewed

Plasmas and Controlled Nuclear Fusion

Contains reports on thirteen research projects split into three sections.National Science Foundation (Grant GK-2581

Plasmas and Controlled Nuclear Fusion

Contains research objectives and reports on three research projects.National Science Foundation (Grant GK-1165

Plasmas and Controlled Nuclear Fusion

Contains research objectives and reports on three research projects.National Science Foundation (Grant GK-1165)National Science Foundation (Grant GK-57

Astrocytic Ion Dynamics: Implications for Potassium Buffering and Liquid Flow

We review modeling of astrocyte ion dynamics with a specific focus on the implications of so-called spatial potassium buffering, where excess potassium in the extracellular space (ECS) is transported away to prevent pathological neural spiking. The recently introduced Kirchoff-Nernst-Planck (KNP) scheme for modeling ion dynamics in astrocytes (and brain tissue in general) is outlined and used to study such spatial buffering. We next describe how the ion dynamics of astrocytes may regulate microscopic liquid flow by osmotic effects and how such microscopic flow can be linked to whole-brain macroscopic flow. We thus include the key elements in a putative multiscale theory with astrocytes linking neural activity on a microscopic scale to macroscopic fluid flow.Comment: 27 pages, 7 figure

Neurophysiology

Contains reports on twenty research projects.Bell Laboratories (Grant)National Institutes of Health (Grant 5 R01 EY01149-03S2)National Institutes of Health (Grant 5 TO1 EY00090-04)National Institutes of Health (Grant 5 RO1 NS12307-03)National Institutes of Health (Grant K04 NS00010)National Multiple Sclerosis Society (Grant RG-1133-A-1)Health Sciences Fund (Grant 78-10