Assessment of Health Needs in Rural America: A Comparison of Amish and Non-Amish Families

This study examines a state-sponsored initiative to identify the primary health needsin rural areas so that the appropriateness of existing programs and services could bedetermined, and the development of new ones could be planned. Data were collectedthrough a survey of 200 families, 50 of whom were Amish. Relatively few differencesexisted between Amish and non-Amish families on health status and use of biomedicalservices; however, Amish families reported more behavioral risk factors and usedmore alternative therapies. Benefits from this assessment and planning process wereincreased public awareness about county health problems, and increased cooperationbetween the formal biomedical care system and the Amish community

THE STOPPING POWER OF WATER: ARE MARITIME STATES MORE LIKELY TO BUCK-PASS THAN LAND POWERS?

While most countries in East Asia have moved closer to the United States to balance against a People’s Republic of China that is increasingly flexing its military capability, several island nations of the Western Pacific have remained relatively passive and have carefully avoided picking sides in this nascent Sino-American competition. Vietnam, which shares a land border with China, is a regional actor that has made remarkable efforts to balance against China. The thesis explores the issue of whether land powers are more likely to balance against Chinese military capabilities than island nations; it is intended to determine if the differences in strategic behavior are related to the geographic setting of various states. The thesis asks if maritime states are more likely to pursue a buck-passing strategy than continental nations. The thesis conducts a comparative study between the strategic behavior of Vietnam as a nation connected to China by a land border and the behavior of Malaysia and the Philippines, which are separated by a maritime obstacle from China. It finds that continental states tend to see “common” threats as more dangerous than do maritime nations. In the language of international relations theory, land powers tend to balance while maritime powers tend to buck-pass. The thesis offers the refinement that as maritime capabilities grow and the “stopping power of water” diminishes, the less viable a buck-passing strategy becomes for island nations.Outstanding ThesisOberstleutnant i.G., German ArmyApproved for public release. Distribution is unlimited

Universality of Electron Mobility in LaAlO3_3/SrTiO3_3 and bulk SrTiO3_3

Metallic LaAlO$_3$/SrTiO$_3$ (LAO/STO) interfaces attract enormous attention, but the relationship between the electron mobility and the sheet electron density, $n_s$, is poorly understood. Here we derive a simple expression for the three-dimensional electron density near the interface, $n_{3D}$, as a function of $n_s$ and find that the mobility for LAO/STO-based interfaces depends on $n_{3D}$ in the same way as it does for bulk doped STO. It is known that undoped bulk STO is strongly compensated with $N \simeq 5 \times 10^{18}~\rm{cm^{-3}}$ background donors and acceptors. In intentionally doped bulk STO with a concentration of electrons $n_{3D} < N$ background impurities determine the electron scattering. Thus, when $n_{3D} < N$ it is natural to see in LAO/STO the same mobility as in the bulk. On the other hand, in the bulk samples with $n_{3D} > N$ the mobility collapses because scattering happens on $n_{3D}$ intentionally introduced donors. For LAO/STO the polar catastrophe which provides electrons is not supposed to provide equal number of random donors and thus the mobility should be larger. The fact that the mobility is still the same implies that for the LAO/STO the polar catastrophe model should be revisited.Comment: 4 pages and 1 figur

The stator complex of the A1A0-ATP synthase--structural characterization of the E and H subunits.

Archaeal ATP synthase (A-ATPase) is the functional homolog to the ATP synthase found in bacteria, mitochondria and chloroplasts, but the enzyme is structurally more related to the proton-pumping vacuolar ATPase found in the endomembrane system of eukaryotes. We have cloned, overexpressed and characterized the stator-forming subunits E and H of the A-ATPase from the thermoacidophilic Archaeon, Thermoplasma acidophilum. Size exclusion chromatography, CD, matrix-assisted laser desorption ionization time-of-flight mass spectrometry and NMR spectroscopic experiments indicate that both polypeptides have a tendency to form dimers and higher oligomers in solution. However, when expressed together or reconstituted, the two individual polypeptides interact with high affinity to form a stable heterodimer. Analyses by gel filtration chromatography and analytical ultracentrifugation show the heterodimer to have an elongated shape, and the preparation to be monodisperse. Thermal denaturation analyses by CD and differential scanning calorimetry revealed the more cooperative unfolding transitions of the heterodimer in comparison to those of the individual polypeptides. The data are consistent with the EH heterodimer forming the peripheral stalk(s) in the A-ATPase in a fashion analogous to that of the related vacuolar ATPase

Quantization of Hall Resistance at the Metallic Interface between an Oxide Insulator and SrTiO3_{3}

The two-dimensional metal forming at the interface between an oxide insulator and SrTiO3 provides new opportunities for oxide electronics. However, the quantum Hall effect, one of the most fascinating effects of electrons confined in two dimensions, remains underexplored at these complex oxide heterointerfaces. Here, we report the experimental observation of quantized Hall resistance in a SrTiO3 heterointerface based on the modulation-doped amorphous-LaAlO$_{3}$/SrTiO$_{3}$ heterostructure, which exhibits both high electron mobility exceeding 10000 cm$^{2}$/Vs and low carrier density on the order of ~10$^{12}$ cm$^{-2}$. Along with unambiguous Shubnikov-de Haas oscillations, the spacing of the quantized Hall resistance suggests that the interface is comprised of a single quantum well with ten parallel conducting two-dimensional subbands. This provides new insight into the electronic structure of conducting oxide interfaces and represents an important step towards designing and understanding advanced oxide devices

Grain size analysis in permanent magnets from Kerr microscopy images using machine learning techniques

Understanding the relationships between composition, structure, processing and properties helps in the development of improved materials for known applications as well as for new applications. Materials scientists, chemists and physicists have researched these relationships for many years, until the recent past, by characterizing the bulk properties of functional materials and describing them with theoretical models. Magnets are widly used in electric vehicles (EV), hybrid electric vehicles (HEV), data storage, power generation and transmission, sensors etc. The search for novel magnetic phases requires an efficient quantitative microstructure analysis of microstructural information like phases, grain distribution and micromagnetic structural information like domain patterns, and correlating the information with intrinsic magnetic parameters of magnet samples. The information out of micromagnetic domains helps in obtaining the optimized microstructures in magnets that have good intrinsic magnetic properties. This paper is aimed at introducing the use of a traditional machine learning (ML) model with a higher dimensional feature set and a deep learning (DL) model to classify various regions in sintered NdFeB magnets based on Kerr-microscopy images. The obtained results are compared against reference data, which is generated manually by subject experts. Additionally, the results were compared against the approach for grain analysis, which is based on the electron backscatter diffraction (EBSD) technique. Further, the challenges faced by the traditional machine learning model for classifying microstructures in Kerr micrographs are discussed

Evidence of weak superconductivity at the room-temperature grown LaAlO₃/SrTiO₃ interface

The two-dimensional electron gas at the crystalline LaAlO3/SrTiO3 (c-LAO/STO) interface has sparked large interest due to its exotic properties, including an intriguing gate-tunable superconducting phase. While there is growing evidence of pronounced spatial inhomogeneity in the conductivity at STO-based interfaces, the consequences for superconductivity remain largely unknown. We study interfaces based on amorphous LAO top layers grown at room temperature (a-LAO/STO) and demonstrate a superconducting phase similar to c-LAO/STO, however, with a gate-tunable critical temperature of 460 mK. The dependence of the superconducting critical current on temperature, magnetic field, and back-gate-controlled doping is found to be consistently described by a model of a random array of Josephson-coupled superconducting domains

Patterning of high mobility electron gases at complex oxide interfaces

Oxide interfaces provide an opportunity for electronics. However, patterning of electron gases at complex oxide interfaces is challenging. In particular, patterning of complex oxides while preserving a high electron mobility remains underexplored and inhibits the study of quantum mechanical effects where extended electron mean free paths are paramount. This letter presents an effective patterning strategy of both the amorphous-LaAlO$_3$/SrTiO$_3$ (a-LAO/STO) and modulation-doped amorphous- LaAlO$_3$/La$_{7/8}$Sr$_{1/8}$MnO$_3$/SrTiO$_3$ (a-LAO/LSM/STO) oxide interfaces. Our patterning is based on selective wet etching of amorphous-LSM (a-LSM) thin films which acts as a hard mask during subsequent depositions. Strikingly, the patterned modulation-doped interface shows electron mobilities up to ~8,700 cm$^2$/Vs at 2 K, which is among the highest reported values for patterned conducting complex oxide interfaces that usually are ~1,000 cm$^2$/Vs at 2 K