Hold the Cracks

My medicine has its own special place in our downstairs bathroom. It rests on a little metal shelf by the shower, standing among the bright orange bottles of multivitamins, B12, vitamin C, and calcium chews. My mother is obsessed with natural healing practices – she slathers on bitter goldenseal for infections, feeds us capsules of powdery white willow bark for headaches, and strange clay mixed with water for stomach aches. My little bottle of pink goo looks lost and confused amidst the hand-written labels and bottles of earth-colored liquids. I feel guilty taking it, but almost proud at the same time. It feels so official, taking “real” medicine. It\u27s like the feeling of eating “real” cereal, as opposed to the hot mush my mother always makes when we’re home. It’s like going to tae kwon do class and being a “real” student as opposed to one who learns everything at home. I never felt quite real, quite normal. I knew that I wasn\u27t. As I swallow the thick, candy-flavored substance, I try to block out the voices seeping in from the kitchen. There is nothing more upsetting than those voices – the low, fearful, angry ones that mean they are either displeased with us (my siblings and I), or talking about money

Reactor power systems for manned earth orbital applications

Design requirements for reactor power system of manned earth orbital space statio

Human Genetic Isolation and Population Structure of Hancock County, Tennessee

A study of the population structure of Hancock County, Tennessee, was conducted in order to determine the degree of genetic isolation, and the likelihood of random genetic drift, experienced by the county population. Genealogical information for the study was obtained from a random sample of the population utilizing two series of questionnaires. In all, data were obtained for 275 couples from all areas of Hancock County. Four main analytical steps were taken with these data to determine: (1) the amount of inbreeding, through a surname isonymy study, (2) the effective population size, (3) the patterns of human movement, primarily marital movement, and its main components--distribution, orientation, and diffusion, and (4) the coefficient of breeding isolation, the indicator of human genetic isolation. The surname isonymy study indicated a much greater amount of inbreeding in the population in the past with a tendency toward breakdown during the last generation due to increased mobility of the population. This increased movement, moreover, was found to exhibit distinct orientations corresponding closely to the main avenues into and out of the county, and also to be limited somewhat in space to an area of approximately 20 miles around Hancock County. The coefficient of breeding isolation, the product of the effective population size and the effective immigration rate, was found to be in agreement with the indications of the inbreeding study. Although it was found to be of too great a magnitude during the last generation for the degree of isolation necessary for the development of genetic diversification, all indications are that as recently as only one generation back genetic isolation experienced by the county population was much greater. When the gene frequencies of the Melungeons, one segment of the Hancock County population, were compared with those of other populations of the United States and England they were found to fall outside the range of these other populations in all but one case. From this it can be concluded that a degree of genetic isolation necessary for random genetic drift was almost assuredly experienced by the Hancock County population in the past, and that this isolation has resulted in altered gene frequencies for this population

Inlet spillage drag tests and numerical flow-field analysis at subsonic and transonic speeds of a 1/8-scale, two-dimensional, external-compression, variable-geometry, supersonic inlet configuration

Accurate spillage drag and pressure data are presented for a realistic supersonic inlet configuration. Results are compared with predictions from a finite-differencing, inviscid analysis computer procedure. The analytical technique shows good promise for the evaluation of inlet drag, but necessary refinements were identified. A detailed description of the analytical procedure is contained in the Appendix

Environmental impact of various kayak core materials

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 26).This thesis compares the environmental impact of fiberglass, Kevlar, carbon fiber, and cork. A kayak company is interested in using cork as a core material, and would like to claim that it is the most environmentally friendly of the four materials listed above. The efficacy of that claim is evaluated by modeling the manufacturing process, generating an input - output model and performing an exergy analysis. The environmental impact of kayak core material construction on the over impact of kayak construction is nominal. Beyond that, the comparison of core materials results in a qualitative ranking from least to most impact, which is fiberglass, cork, carbon fiber then Kevlar. The diversity of impact, from noxious gases, energy use, volatile liquids, land use and toxic wastes necessitates a qualitative analysis when full exergy data wasn't available. Because of this, the comparison was quantitatively based on the energy use and qualitatively based on each chemicals material safety data.by David R. Kirkland.S.B

Outstanding Educational Performance Awards: Highlighting Top Achieving Arkansas Schools, 2009

Since our founding in 2003, the mission of the Office for Education Policy has been to look at pressing issues through the lens of academic research and disseminate our findings to educators, policymakers, and other stakeholders around Arkansas. Every once in a while, however, we think it is okay to stray from issue analysis and simply share some good news! So, in this Arkansas Education Report (AER) we merely aim to highlight excellent performance and give our congratulations. To that end, we are happy to highlight the top performing schools around the state in an annual AER entitled the Outstanding Educational Performance Awards

Strategies towards statistically robust interpretations of in situ U–Pb zircon geochronology

Zircon U–Pb geochronology has become a keystone tool across Earth science, arguably providing the gold standard in resolving deep geological time. The development of rapid in situ analysis of zircon (via laser ablation and secondary ionization mass spectrometry) has allowed for large amounts of data to be generated in a relatively short amount of time and such large volume datasets offer the ability to address a range of geological questions that would otherwise remain intractable (e.g. detrital zircons as a sediment fingerprinting method). The ease of acquisition, while bringing benefit to the Earth science community, has also led to diverse interpretations of geochronological data. In this work we seek to refocus U–Pb zircon geochronology toward best practice by providing a robust statistically coherent workflow. We discuss a range of data filtering approaches and their inherent limitations (e.g. discordance and the reduced chi-squared; MSWD). We evaluate appropriate mechanisms to calculate the most geologically appropriate age from both 238U/206Pb and 207Pb/206Pb ratios and demonstrate the cross over position when chronometric power swaps between these ratios. As our in situ analytical techniques become progressively more precise, appropriate statistical handing of U–Pb datasets will become increasingly pertinent