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Spectroscopic data from a var iety of analyt ical techniques such as x-ray diffraction (XRD), infrared (IR) and Raman spectroscopies, secondary ion mass spectrometry (SIMS) and energy dispersive X-ray analysis (EDX) can be obtained from small areas of samples (< 1 mm2) through the use of microscope sampling accessories. If provisions are made to scan or translate the sample, then a spectrum that is characteristic of each region of interest can be obtained. Alternatively, selective area detectors eliminate the requirement for scanning the sample. Extract ion of information about a specific energy band from each spectrum allows elucidat ion of the spatial distribution of the feature giving rise to that band. For example, the distribution of a compound could be imaged by extracting the intensity of an IR band or XRD peak due to that compound. Peak posit ion and peak width are other parameters that can be extracted as a function of posit ion. Similarly, elemental distributions could be obtained using SIMS and EDX.
Non-communicable diseases are projected to become the most common causes of death in Africa by 2030. The impact on health of epidemiological and nutritional transitions in sub-Saharan Africa remains unclear. To assess the trends of dietary fatty acids over time in Uganda, we examined fatty acids in serum collected from individuals in rural south-west Uganda, at three time points over two decades. Independent cross-sectional samples of 915 adults and children were selected from the general population cohort in 1990 (n 281), 2000 (n 283) and 2008 (n 351). Serum phospholipid fatty acids were measured by GC. Multivariate regression analyses were performed to compare the geometric means of fatty acids by time period. Serum fatty acid profiling showed high proportions of SFA, cis-MUFA and industrial trans-fatty acids (iTFA), likely to be biomarkers of high consumption of palm oil and hydrogenated fats. In contrast, proportions of n-6 and n-3 PUFA from vegetable oils and fish were low. From 1990 to 2008, serum phospholipids showed increases in absolute amounts of SFA (17·3 % increase in adults and 26·4 % in children), MUFA (16·7 % increase in adults and 16·8 % in children) and n-6:n-3 PUFA (40·1 % increase in adults and 39·8 % in children). The amount of elaidic acid, iTFA from hydrogenated fats, increased in children (60·1 % increase). In this rural Ugandan population, we show evidence of unfavourable trends over time of dietary fatty acids.
Background: Approximately 12-15% of patients with intracranial aneurysms (IA) have affected first-degree relatives, and are considered to have familial intracranial aneurysms (FIA). Individuals with FIA are at higher risk for aneurysm formation and subarachnoid hemorrhage. THSD1 is the only gene to be associated with nonsyndromic FIA at this time. Our study aims to find rare DNA variants that are major risk factors for FIA in our cohort of patients. Methods: To date we have enrolled 37 affected and 31 unaffected people from 16 families. We have done exome or genome sequencing on at least 1 person from each of 12 families. Results: A rare p.(R686W) variant in THSD1 was found in 1/12 families, but did not cosegregate fully with disease. While less attractive as the primary cause of FIA, we cannot rule out the potential modifying effects of THSD1 p.(R686W) in this family. A second candidate, an extracellular matrix gene within a chromosomal region previously implicated by familial mapping studies, contains rare variants in 4/12 of our families. All four variants are predicted to be damaging. Conclusions: Alongside environmental risk factors, individual FIA families may also have complex rare variant contributions to their disease, such as digenic and multi-locus contributions.
We have mapped cold atomic gas in 21cm line H i self-absorption (HISA) at arcminute resolution over more than 90% of the Milky Way's disk. To probe the formation of H2 clouds, we have compared our HISA distribution with CO J = 1-0 line emission. Few HISA features in the outer Galaxy have CO at the same position and velocity, while most inner-Galaxy HISA has overlapping CO. But many apparent inner-Galaxy HISA-CO associations can be explained as chance superpositions, so most inner-Galaxy HISA may also be CO-free. Since standard equilibrium cloud models cannot explain the very cold H i in many HISA features without molecules being present, these clouds may instead have significant CO-dark H2.
Common pharmacological treatments of mood disorders aim to modulate serotonergic neurotransmission and enhance serotonin levels in the brain. Brain serotonin levels are dependent on the availability of its food-derived precursor essential amino acid tryptophan (Trp). We tested the hypothesis that delivery of Trp via food may serve as an alternative treatment, and examined the effects of a Trp-rich, bioavailable dietary supplement from egg protein hydrolysate on cognitive and emotional functions, mood state, and sleep quality. In a randomised, placebo-controlled, parallel trial, fifty-nine mentally and physically healthy women aged 45–65 years received placebo (n 30) or the supplement (n 29) (both as 0·5 g twice per d) for 19 d. Emotional processing was significantly changed by supplementation, exhibiting a shift in bias away from negative stimuli. The results for the Affective Go/No-Go Task exhibited a slowing of responses to negative words, suggesting reduced attention to negative emotional stimuli. The results for the Facial Emotional Expression Rating Task also supported a shift away from attention to negative emotions and a bias towards happiness. An increase in arousal-like symptoms, labelled ‘high energy’, shorter reaction times and a slight benefit to sustained attention were observed in the treated subjects. Finally, when the supplement was taken 60–90 min before bedtime, a feeling of happiness before going to bed was consistently reported. In summary, daily consumption of a low-dose supplement containing bioavailable Trp may have beneficial effects on emotional and cognitive functions.
This study aimed to determine the potential role and guidelines for implementation of skill-based peer mentoring for radiotherapy planning education.
After four weekly mentoring sessions, both Year 3 mentors (n=9) and Year 2 mentees (n=9) were invited to complete a short online questionnaire relating to the impact of the initiative. The tool contained a mixture of Likert-style questions concerning student enjoyment and perceived usefulness of the initiative as well as more qualitative open questions that gathered perceptions of the peer mentoring process, implementation methods and potential future scope.
Several key discussion themes related to benefits to each stakeholder group, challenges arising, improvements and potential future directions. There were high levels of enjoyment and perceived value of the mentoring from both sides with 100% of the 18 respondents enjoying the experience. The informal format encouraged further learning, while mentors reported acquisition of valuable skills and gains in knowledge.
Peer mentoring has a valuable and enjoyable role to play in radiotherapy planning training and helps consolidate theoretical understanding for experienced students. An informal approach allows for students to adopt the most appropriate mentoring model for their needs while providing them with a free space to engender additional discussion.
We are engaged in a study of the current and past condition of party organizations in the United States. The research examines parties within an institutional framework and seeks to measure the strength of party organizations at the national, state, and local levels. But in order to compare parties over time it is necessary to have longitudinal data. The purpose of this note is to ask interested researchers to share with us documented data on state party central committee staff and annual operating budgets or expenditures for the period 1960–1978. We would also appreciate suggestions for sources of such data for any of the state parties.
Table 1 presents the state party central committee budget and staff data collected to date. The 21-year period 1960–1980 yields 2,100 possible data points for the 100 state party organizations. We have collected budget data for 964 (45.9 percent) and staff data for 1,000 (47.6 percent) of the data points. These data have come from a variety of sources:
1. interviews with state party officials in 27 sample states (states selected for analysis in the cross-sectional portion of our research;
2. questionnaires sent to 556 former state party chairmen;
3. surveys by Roland H. Ebel, Cornelius P. Cotter, and Bernard C. Hennessy;
4. data collected and generously made available by William J. Crotty;
5. Jerome M. Mileur's 1977 survey of state party central committees;
6. Robert J. Huckshorn's collection of state party data;
7. surveys conducted by the Democratic National Committee in 1962, the Republican National Committee in 1968–69, and by the president of the Association of State Democratic Chairmen in 1974.
The Dominion Radio Astrophysical Observatory (DRAO) is carrying out a survey as part of an international collaboration to image the northe, at a common resolution, in emission from all major constituents of the interstellar medium; the neutral atomic gas, the molecular gas, the ionised gas, dust and relativistic plasma. For many of these constituents the angular resolution of the images (1 arcmin) will be more than a factor of 10 better than any previous studies. The aim is to produce a publicly-available database of high resolution, high-dynamic range images of the Galaxy for multi-phase studies of the physical states and processes in the interstellar medium. We will sketch the main scientific motivations as well as describe some preliminary results from the Canadian Galactic Plane Survey/Releve Canadien du Plan Galactique (CGPS/RCPG).
The Magellanic System represents one of the best places to study the formation and evolution of galaxies. Photometric surveys of various depths, areas and wavelengths have had a significant impact on our understanding of the system; however, a complete picture is still lacking. VMC (the VISTA near-infrared YJKs survey of the Magellanic System) will provide new data to derive the spatially resolved star formation history and to construct a three-dimensional map of the system. These data combined with those from other ongoing and planned surveys will give us an absolutely unique view of the system opening up the doors to truly new science!
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Self-organized Ge-dots on (001)-oriented Si-substrates have been studied using two-dimensionally resolved high resolution x-ray diffraction and reflectivity. The degree of the vertical correlation of the dot positions ("stacking") has been derived as well as a lateral ordering of the dots in a (disordered) square array with main axes parallel to ]100] and ]010].
ZnSe/GaAs heterojunctions were investigated by contactless electroreflectance and photoreflectance techniques. Negative surface charge densities on the order of 1012 cm-2 were observed for films grown on n-type GaAs indicating a large contribution to the conduction band barrier between the materials due to band bending. The conduction band offset was also measured using a new photoreflectance technique involving a tunable pump laser.
Three important oxidation regimes have been identified in the temporal evolution of the wet thermal oxidation of AlxGa1-xAs (1 ≥ x ≥ 0.90) on GaAs: 1) oxidation of Al and Ga in the AlxGa1-xAs alloy to form an amorphous oxide layer, 2) oxidative formation and elimination of elemental As (both crystalline and amorphous) and of amorphous As2O3, and 3) crystallization of the oxide film. Residual As can result in up to a 100-fold increase in leakage current and a 30% increase in the dielectric constant and produce strong Fermi-level pinning and high leakage currents at the oxidized AlxGa1-xAs/GaAs interface. The presence of thermodynamically-favored interfacial As may impose a fundamental limitation on the application of AlGaAs wet oxidation for achieving MIS devices in the GaAs material system.
The use of thiourea/ammonia pre-treatments on (100) InP, followed by chemical bath deposition (CBD) of CdS thin films (∼ 30 Å), with low-temperature, low-pressure chemical vapor deposited SiO2 has been shown to produce metal-insulator-semiconductor (MIS) samples with near-ideal capacitance-voltage (C-V) response. Here, we report on x-ray photoelectron spectroscopy (XPS) analysis of the near-surface of InP following pre-treatment and CdS deposition. The pre-treatment was shown by XPS to form an indium sulfide layer and effectively remove native oxides from the InP surface. The subsequent deposition of CdS on a sulfur-passivated surface forms a stable layer which protects the substrate from oxidation during SiO2 chemical vapor deposition. MIS samples prepared using the pre-treatment without CdS deposition showed improved C- V response, while samples prepared with both the pre-treatment and CdS deposition showed a dramatic reduction in the density of interface states.
In this study the SCP (Surface Charge Profiling) method, based on non-contact, small-signal ac-SPV measurement is used to study thermal activation of boron in the near surface region of p-type Si wafers. Boron tends to form pairs with impurities such as hydrogen, iron and copper in the near surface region of Si substrates which render it inactive. During device processing, activation of boron may take place resulting in uncontrolled variations in active boron concentration in the near surface region.
In this work, both boron doped, polished CZ wafers and wafers with boron doped epitaxial layers are studied. In the former case, the concentration of active boron in the near surface region was initially up to an order of magnitude less than the bulk concentration determined from four-probe measurements, but increased with the temperature of an anneal in ambient air and approached the bulk value. In contrast, the wafers with epitaxial layers showed no consistent variations of surface dopant concentration with temperature. These results confirmed previous findings that the near surface region of the polished wafers is contaminated with metals introduced during polishing operations. The SCP method was found to be very effective in monitoring variations in active boron concentration in the near-surface region.