Recoil Implantation Using Gas-Phase Precursor Molecules

Ion implantation underpins a vast range of devices and technologies that require precise control over the physical, chemical, electronic, magnetic and optical properties of materials. A variant termed “recoil implantation” – in which a precursor is deposited onto a substrate as a thin film and implanted via momentum transfer from incident energetic ions – has a number of compelling advantages, particularly when performed using an inert ion nano-beam [Fröch et al., Nat. Commun., 2020, 11, 5039]. However, a major drawback of this approach is that the implant species are limited to the constituents of solid thin films. Here we overcome this limitation by demonstrating recoil implantation using gas-phase precursors. Specifically, we fabricate nitrogen-vacancy (NV) color centers in diamond using an Ar+ ion beam and the nitrogen-containing precursor gases N2, NH3 and NF3. Our work expands the applicability of recoil implantation with the potential to be suitable to a larger portion of the periodic table, and to applications in which thin film deposition/removal is impractical

Accuracy of telepsychiatric assessment of new routine outpatient referrals

<p>Abstract</p> <p>Background</p> <p>Studies on the feasibility of telepsychiatry tend to concentrate only on a subset of clinical parameters. In contrast, this study utilises data from a comprehensive assessment. The main objective of this study is to compare the accuracy of findings from telepsychiatry with those from face to face interviews.</p> <p>Method</p> <p>This is a primary, cross-sectional, single-cluster, balanced crossover, blind study involving new routine psychiatric referrals. Thirty-seven out of forty cases fulfilling the selection criteria went through a complete set of independent face to face and video assessments by the researchers who were blind to each other's findings.</p> <p>Results</p> <p>The accuracy ratio of the pooled results for DSM-IV diagnoses, risk assessment, non-drug and drug interventions were all above 0.76, and the combined overall accuracy ratio was 0.81. There were substantial intermethod agreements for Cohen's kappa on all the major components of evaluation except on the Risk Assessment Scale where there was only weak agreement.</p> <p>Conclusion</p> <p>Telepsychiatric assessment is a dependable method of assessment with a high degree of accuracy and substantial overall intermethod agreement when compared with standard face to face interview for new routine outpatient psychiatric referrals.</p

Atomistic model of diopside–K-jadeite (CaMgSi2O6–KAlSi2O6) solid solution

Atomistic model was proposed to describe the thermodynamics of mixing in the diopside–K-jadeite solid solution (CaMgSi2O6–KAlSi2O6). The simulations were based on minimization of the latticeenergies of 800 structures within a 2 × 2 × 4 supercell of C2/c diopside with the compositions betweenCaMgSi2O6 and KAlSi2O6 and with variable degrees of order/disorder in the arrangement of Ca/K cations in M2 site and Mg/Al in Ml site. The energy minimization was performed with the help of a force-field model. The results of the calculations were used to define a generalized Ising model, which included 37 pair interaction parameters. Isotherms of the enthalpy of mixing within the range of 273–2023 K were calculated with a Monte Carlo algorithm, while the Gibbs free energies of mixing were obtained by thermodynamic integration of the enthalpies of mixing. The calculated T–X diagram for the system CaMgSi2O6–KAlSi2O6 at temperatures below 1000 K shows several miscibility gaps, which are separated by intervals of stability of intermediate ordered compounds. At temperatures above 1000 K a homogeneous solid solution is formed. The standard thermodynamic properties of K-adeite (KAlSi2O6) evaluated from quantum mechanical calculations were used to determine location of several mineral reactions with the participation of the diopside–K-jadeite solid solution. The results of the simulations suggest that the low content of KalSi2O6 in natural clinopyroxenes is not related to crystal chemical factors preventing isomorphism, but is determined by relatively high standard enthalpy of this end member

Null Mutations in EphB Receptors Decrease Sharpness of Frequency Tuning in Primary Auditory Cortex

Primary auditory cortex (A1) exhibits a tonotopic representation of characteristic frequency (CF). The receptive field properties of A1 neurons emerge from a combination of thalamic inputs and intracortical connections. However, the mechanisms that guide growth of these inputs during development and shape receptive field properties remain largely unknown. We previously showed that Eph family proteins help establish tonotopy in the auditory brainstem. Moreover, other studies have shown that these proteins shape topography in visual and somatosensory cortices. Here, we examined the contribution of Eph proteins to cortical organization of CF, response thresholds and sharpness of frequency tuning. We examined mice with null mutations in EphB2 and EphB3, as these mice show significant changes in auditory brainstem connectivity. We mapped A1 using local field potential recordings in adult EphB2−/−;EphB3−/− and EphB3−/− mice, and in a central A1 location inserted a 16-channel probe to measure tone-evoked current-source density (CSD) profiles. Based on the shortest-latency current sink in the middle layers, which reflects putative thalamocortical input, we determined frequency receptive fields and sharpness of tuning (Q20) for each recording site. While both mutant mouse lines demonstrated increasing CF values from posterior to anterior A1 similar to wild type mice, we found that the double mutant mice had significantly lower Q20 values than either EphB3−/− mice or wild type mice, indicating broader tuning. In addition, we found that the double mutants had significantly higher CF thresholds and longer onset latency at threshold than mice with wild type EphB2. These results demonstrate that EphB receptors influence auditory cortical responses, and suggest that EphB signaling has multiple functions in auditory system development

Localization of type 1 diabetes susceptibility to the MHC class I genes HLA-B and HLA-A

The major histocompatibility complex (MHC) on chromosome 6 is associated with susceptibility to more common diseases than any other region of the human genome, including almost all disorders classified as autoimmune. In type 1 diabetes the major genetic susceptibility determinants have been mapped to the MHC class II genes HLA-DQB1 and HLA-DRB1 (refs 1-3), but these genes cannot completely explain the association between type 1 diabetes and the MHC region. Owing to the region's extreme gene density, the multiplicity of disease-associated alleles, strong associations between alleles, limited genotyping capability, and inadequate statistical approaches and sample sizes, which, and how many, loci within the MHC determine susceptibility remains unclear. Here, in several large type 1 diabetes data sets, we analyse a combined total of 1,729 polymorphisms, and apply statistical methods - recursive partitioning and regression - to pinpoint disease susceptibility to the MHC class I genes HLA-B and HLA-A (risk ratios >1.5; Pcombined = 2.01 × 10-19 and 2.35 × 10-13, respectively) in addition to the established associations of the MHC class II genes. Other loci with smaller and/or rarer effects might also be involved, but to find these, future searches must take into account both the HLA class II and class I genes and use even larger samples. Taken together with previous studies, we conclude that MHC-class-I-mediated events, principally involving HLA-B*39, contribute to the aetiology of type 1 diabetes. ©2007 Nature Publishing Group

Fate of nitrate in seepage from a restored wetland receiving agricultural tailwater

Constructed and restored wetlands are a common practice to filter agricultural runoff, which often contains high levels of pollutants, including nitrate. Seepage waters from wetlands have potential to contaminate groundwater. This study used soil and water monitoring and hydrologic and nitrogen mass balances to document the fate and transport of nitrate in seepage and surface waters from a restored flow-through wetland adjacent to the San Joaquin River, California. A 39% reduction in NO3-N concentration was observed between wetland surface water inflows (12.87±6.43mgL-1; mean±SD) and outflows (7.87±4.69mgL-1). Redox potentials were consistently below the nitrate reduction threshold (~250mV) at most sites throughout the irrigation season. In the upper 10cm of the main flowpath, denitrification potential (DNP) for soil incubations significantly increased from 151 to 2437mgNO3-Nm-2d-1 when nitrate was added, but showed no response to carbon additions indicating that denitrification was primarily limited by nitrate. Approximately 72% of the water entering the wetland became deep seepage, water that percolated beyond 1-m depth. The wetland was highly effective at removing nitrate (3866kgNO3-N) with an estimated 75% NO3-N removal efficiency calculated from a combined water and nitrate mass balance. The mass balance results were consistent with estimates of NO3-N removed (5085kgNO3-N) via denitrification potential. Results indicate that allowing seepage from wetlands does not necessarily pose an appreciable risk for groundwater nitrate contamination and seepage can facilitate greater nitrate removal via denitrification in soil compared to surface water transport alone

Proceedings of the Fourth Caldwell Conference, St. Catherines Island, Georgia, March 27-29, 2009.

391 p. : ill. (chiefly col.), maps (chiefly col.) ; 26 cm. "Issued March 23, 2011."This edited volume addresses the geoarchaeology of St. Catherines Island (Georgia). The field of geoarchaeology has typically been defined as either geology pursued within an archaeological framework or (sometimes the reverse) as archaeology framed with the help of geological methodology. Either way, the formalized objectives of geoarchaeology define a broad range of pursuits, from placing archaeological sites into relative and absolute temporal context through the application of stratigraphic principles and absolute dating techniques, to understanding the natural processes of site formation, to reconstructing the landscapes that existed around a site or group of sites at the time of occupation. The editors of this volume have generally followed the lead of G.R. Rapp and C.L. Hill (2006, Geoarchaeology : the earth-science approach to archaeological interpretation) by stressing the importance of multiple viewpoints and methodologies in applying geoscience techniques to evaluate the archaeological record. In the broadest sense, then, Geoarchaeology of St. Catherines Island applies multiple earth science concepts, techniques, or knowledge bases to the known archaeological record and the processes that created that record. This volume consists of 16 papers presenting the newest research on the stratigraphic and geomorphological evolution of the St. Catherines Island landscape. Of particular interest are presentations addressing the relative timing and nature of sedimentation, paleobiology, sea level change, stream capture, hydrology, and erosional patterning evident on St. Catherines Island (and to some degree the rest of the Georgia Bight). These papers were initially presented at the Fourth Caldwell Conference, cosponsored by the American Museum of Natural History and the St. Catherines Island Foundation, held on St. Catherines Island (Georgia), March 27-29, 2009. Table of contents: Why this archaeologist cares about geoarchaeology : some pasts and futures of St. Catherines Island / David Hurst Thomas -- Evolution of late Pleistocene-Holocene climates and environments of St. Catherines Island and the Georgia Bight / Fredrick J. Rich, Anthony Vega, and Frank J. Vento -- Geoarchaeological research at St. Catherines Island : defining the geological foundation / Gale A. Bishop, Brian K. Meyer, R. Kelly Vance, and Fredrick J. Rich -- Development of a late Pleistocene-Holocene genetic stratigraphic framework for St. Catherines Island : archaeological implications / Frank J. Vento and Patty A. Stahlman -- Ichnological diagnosis of ancient storm-washover fans, Yellow Banks Bluff, St. Catherines Island / Anthony J. Martin and Andrew K. Rindsberg -- Quaternary vegetation and depositional history of St. Catherines Island / Fredrick J. Rich and Robert K. Booth -- Recent shoreline erosion and vertical accretion patterns, St. Catherines Island / Donald B. Potter Jr. -- Role of storm events in beach ridge formation, St. Catherines Island / Harold B. Rollins, Kathi Beratan, and James E. Pottinger -- Drainage changes at Ossabaw, St. Catherines, and Sapelo sounds and their influence on island morphology and spit building on St. Catherines Island / Timothy M. Chowns -- Vibracores and vibracore transects : constraining the geological and cultural history of St. Catherines Island / Gale A. Bishop, David Hurst Thomas, Matthew C. Sanger, Brian K. Meyer, R. Kelly Vance, Robert K. Booth, Fredrick J. Rich, Donald B. Potter, and Timothy Keith-Lucas -- Application of ground penetrating radar to investigations of the stratigraphy, structure, and hydrology of St. Catherines Island / R. Kelly Vance, Gale A. Bishop, Fredrick J. Rich, Brian K. Meyer, and Eleanor J. Camann -- Postsettlement dispersal and dynamic repopulation of estuarine habitats by adult Mercenaria mercenaria, St. Catherines Island / Robert S. Prezant, Harold B. Rollins, and Ronald B. Toll -- The foundation for sea turtle geoarchaeology and zooarchaeology : morphology of recent and ancient sea turtle nests, St. Catherines Island, Georgia, and Cretaceous Fox Hills Sandstone, Elbert County, Colorado / Gale A. Bishop, Fredric L. Pirkle, Brian K. Meyer, and William A. Pirkle -- Sea turtle habitat deterioration on St. Catherines Island : defining the modern transgression / Gale A. Bishop and Brian K. Meyer -- Modeling indigenous hunting and harvesting of sea turtles and their eggs on the Georgia Coast / Gale A. Bishop, David Hurst Thomas, and Brian K. Meyer -- Geomorphology, sea level, and marine resources : St. Catherines Island / Harold B. Rollins and David Hurst Thomas -- Appendix 1. Noncultural radiocarbon record from St. Catherines Island : a compendium -- Appendix 2. Vibracore record from St. Catherines Island : a compendium.Conference sponsored by the American Museum of Natural History and the St. Catherines Island Foundation