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Chemical bonding in native oxides of GaAs, before and after etching, is detected by X-Ray Photoelectron Spectroscopy (XPS). It is correlated with surface energy engineering (SEE), measured via Three Liquid Contact Angle Analysis (3LCAA), and oxygen coverage, measured by High Resolution Ion Beam Analysis (HR-IBA).
Before etching, GaAs native oxides are found to be hydrophobic with an average surface energy, γT, of 33 ± 1 mJ/m2, as measured by 3LCAA. After dilute NH4OH etching, GaAs becomes highly hydrophilic and its surface energy, γT, increases by a factor 2 to a reproducible value of 66 ± 1 mJ/m2. Using HR-IBA, oxygen coverage on GaAs is found to decrease from 7.2 ± 0.5 monolayers (ML) to 3.6 ± 0.5 ML. The 1.17 ratio of Ga to As, measured by HR-IBA, remains constant after etching.
XPS is used to measure oxidation of Ga and As, as well as surface stoichiometry on two locations of several GaAs(100) wafers before and after etching. The relative proportions of Ga and As are unaffected by adventitious carbon contamination. The 1.16 Ga:As ratio, measured by XPS, matches HR-IBA analysis. The proportions of oxidized Ga and As do not change significantly after etching. However, the initial ratio of As2O5 to As2O3, within the oxidized As, significantly decreases after etching from approximately 3:1 to 3:2.
Absolute oxygen coverage, as a function of surface processing, is determined within 0.5 ML by HR-IBA. XPS offers insight into these modifications by detecting electronic states and phase composition changes of GaAs oxides. The changes in surface chemistry are correlated to changes in hydro-affinity and surface energies measured by 3LCAA.
Background: SMA1 is a neurodegenerative disease caused by bi-allelic survival motor neuron 1 gene (SMN1) deletion/mutation. In the phase 1 study, SMN GRT onasemnogene abeparvovec (AVXS-101) improved outcomes of symptomatic SMA1 patients. We report preliminary data of STR1VE, a pivotal study (NCT03306277) evaluating efficacy and safety of a one-time intravenous AVXS-101 infusion. Methods: STR1VE is a phase 3, multicenter, open-label, single-arm study in SMA1 patients aged <6 months (bi-allelic SMN1 loss, 2xSMN2). Primary outcomes: independent sitting for ≥30 seconds (18 months) and survival (14 months). Secondary outcomes: ability to thrive and ventilatory support (18 months). Exploratory outcomes: CHOP-INTEND and Bayley Scales of Infant and Toddler Development scores. Results: Enrollment is complete with 22 patients dosed. Mean age at symptom onset, genetic diagnosis, and enrollment was 1.9 (0–4.0), 2.1 (0.5–4.0), and 3.7 (0.5–5.9) months. At baseline, no patient required ventilatory/nutritional support, and all exclusively fed by mouth. Mean baseline CHOP-INTEND score was 32.6 (17.0–52.0), which increased 6.9 (-4.0–16.0, n=20), 10.4 (2.0–18.0, n=12), and 11.6 (-3.0–23.0, n=9) points at 1, 2, and 3 months; updates provided at congress. Conclusions: Preliminary data from STR1VE show rapid motor function improvements in SMA1 patients, paralleling phase 1 findings.
Background: SMA is characterized by reduced levels of survival of motor neuron (SMN) protein from deletions and/or mutations of the SMN1 gene. While SMN1 produces full-length SMN protein, a second gene, SMN2, produces low levels of functional SMN protein. Risdiplam (RG7916/RO7034067) is an investigational, orally administered, centrally and peripherally distributed small molecule that modulates pre-mRNA splicing of SMN2 to increase SMN protein levels. Methods: FIREFISH (NCT02913482) is an ongoing, multicenter, open-label operationally seamless study of risdiplam in infants aged 1–7 months with Type 1 SMA and two SMN2 gene copies. Exploratory Part 1 (n=21) assesses the safety, tolerability, pharmacokinetics and pharmacodynamics of different risdiplam dose levels. Confirmatory Part 2 (n=40) is assessing the safety and efficacy of risdiplam. Results: In a Part 1 interim analysis (data-cut 09/07/18), 93% (13/14) of babies had ≥4-point improvement in CHOP-INTEND total score from baseline at Day 245, with a median change of 16 points. The number of infants meeting HINE-2 motor milestones (baseline to Day 245) increased. To date (data-cut 09/07/18), no drug-related safety findings have led to patient withdrawal. No significant ophthalmological findings have been observed. Conclusions: In FIREFISH Part 1, risdiplam improved motor function in infants with Type 1 SMA.
Virtual Reconstruction is a powerful tool broadly suited to a diverse array of archaeological heritage applications. In practice, however, reconstruction has largely focused on grand and monumental sites. Here we present two case studies–one from southern Oklahoma, the other from western Nebraska–to explore the use of this technology for more common heritage applications. The goal of this article is to advertise the dilemma we faced with communicating information on ephemeral sites and how we, as nonspecialists, solved the issue using affordable and accessible digital tools. Our workflow makes use of common tools (GIS) and open source software and online tutorials provide step by step instruction to support its replication. In presenting our experiences and the results of these efforts, we hope to spur similar applications in the use of Virtual Reconstruction to communicate information on archaeological heritage more broadly.
Photoelectric diodes with aluminum photocathod.es have been calibrated in the energy range from 0.1 keV to 1 keV with a multielement Henke X-ray tube system using regenerative monochromatic filters. The calibration is performed at six energies: (1) Be - (0.109 keV) , (2) C - Kα (0.277 keV), (3) Ti – Lα1, 2 (0.452 keV) , (4) Fe – Lα1, 2 (0.705 keV), (5) Cu – Lα1, 2 (0.930 keV), and (6) Al – Kαl, 2 (1.487 keV). Several different 99.9%, (1000 series) aluminum foils were calibrated for use as cathodes. In addition, the average energy per electron ion pair, W, has been measured for methane at these same energies.
Analysis of the total surface energy γT and its three components as established by the van Oss-Chaudhury-Good Theory (vOCG) is conducted via Three Liquid Contact Angle Analysis (3LCAA). γT is correlated with the composition of the top monolayers (ML) obtained from High-Resolution Ion Beam Analysis (HR-IBA). Control of γT enables surface engineering for wafer bonding (Nano-BondingTM) and/or epitaxial growth. Native oxides on boron-doped p-Si(100) are found to average γT of 53 ± 1.4 mJ/m2) and are always hydrophilic. An HF in methanol or aqueous HF etch for 60 s always renders Si(100) hydrophobic. Its γT decreases by 20% to 44 ± 3 mJ/m2 in HF in methanol etch and by 10% to 48 ± 3 mJ/m2 in aqueous HF. On the contrary, GaAs(100) native oxides are found to always be hydrophobic. Tellurium n+-doped GaAs(100) yields an average of γT of 37 ± 2 mJ/m2, 96% of which is due to the Lifshitz-Van der Waals molecular interactions (γLW = 36 ± 1 mJ/m2). However, hydrophobic GaAs(100) can be made highly hydrophilic. After etching, γT increases by almost 50% to 66 ± 1.4 mJ/m2. 3LCAA shows that the γT increase is due to electron acceptor and donor interactions, while the Lifshitz-van der Waals energy γLW remains constant. IBA combining the 3.039 ± 0.01 MeV oxygen nuclear resonance with <111> channeling, shows that oxygen on Si(100) decreases by 10% after aqueous HF etching, from 13.3 ± 0.3 monolayers (ML) to 11.8 ± 0.4 ML 1 hour after etch.Te-doped GaAs(100) exhibits consistent oxygen coverage of 7.2 ± 1.4 ML, decreasing by 50% after etching to a highly hydrophilic surface with 3.6 ± 0.2 oxygen ML. IBA shows that etching does not modify the GaAs surface stoichiometry to within 1% . Combining 3LCAA with HR-IBA provides a quantitative metrology to measure how GaAs and Si surfaces can be altered to a different hydroaffinity and surface termination.
The effects of crystal orientation and doping on the surface energy, γT, of native oxides of Si(100) and Si(111) are measured via Three Liquid Contact Angle Analysis (3LCAA) to extract γT, while Ion Beam Analysis (IBA) is used to detect Oxygen. During 3LCAA, contact angles for three liquids are measured with photographs via the “Drop and Reflection Operative Program (DROP™). DROP™ removes subjectivity in image analysis, and yields reproducible contact angles within < ±1°. Unlike to the Sessile Drop Method, DROP can yield relative errors < 3% on sets of 20-30 drops. Native oxides on 5 x 1013 B/cm3 p- doped Si(100) wafers, as received in sealed, 25 wafer teflon boats continuously stored in Class 100/ISO 5 conditions at 24.5°C in 25% controlled humidity, are found to be hydrophilic. Their γT, 52.5 ± 1.5 mJ/m2, is reproducible between four boats from three sources, and 9% greater than γT of native oxides on n- doped Si(111), which averages 48.1 ± 1.6 mJ/m2 on four 4” Si(111) wafers. IBA combining 16O nuclear resonance with channeling detects 30% more oxygen on native oxides of Si(111) than Si(100). While γT should increase on thinner, more defective oxides, Lifshitz-Van der Waals interactions γLW on native oxides of Si(100) remain at 36 ± 0.4 mJ/m2, equal to γLW on Si(111), 36 ± 0.6 mJ/m2, since γLW arises from the same SiO2 molecules. Native oxides on 4.5 x 1018 B/cm3 p+ doped Si(100) yield a γT of 39 ± 1 mJ/m2, as they are thicker per IBA. In summary, 3LCAA and IBA can detect reproducibly and accurately, within a few %, changes in the surface energy of native oxides due to thickness and surface composition arising from doping or crystal structure, if conducted in well controlled clean room conditions for measurements and storage.
Cucumber powdery mildew is a destructive foliar disease caused by Podosphaera xanthii (formerly known as Sphaerotheca fuliginea) that substantially damages the yield and quality of crops. The control of this disease primarily involves the use of chemical pesticides that cause serious environmental problems. Currently, numerous studies have indicated that some plant extracts or products potentially have the ability to act as natural pesticides to control plant diseases. It has been reported that turmeric (Curcuma longa L.) and its extract can be used in agriculture due to their insecticidal and fungicidal properties. However, the most effective fungicidal component of this plant is still unknown. In the current study, the crude extract of C. longa L. was found to have a fungicidal effect against P. xanthii. Afterwards, eight fractions (Fr.1–Fr.8) were gradually separated from the crude extract by column chromatography. Fraction 1 had the highest fungicidal effect against this pathogen among the eight fractions. The active compound, (+)-(S)-ar-turmerone, was separated from Fr 1 by semi-preparative high-performance liquid chromatography and identified based on its 1H nuclear magnetic resonance (NMR) and 13C NMR spectrum data. The EC50 value of (+)-(S)-ar-turmerone was found to be 28.7 µg/ml. The compound also proved to have a curative effect. This is the first study to report that the compound (+)-(S)-ar-turmerone has an effect on controlling this disease. These results provide a basis for developing a new phytochemical fungicide from C. longa L. extract.
Multiple human immunodeficiency virus (HIV)-1 genotypes in China were first discovered in Yunnan Province before disseminating throughout the country. As the HIV-1 epidemic continues to expand in Yunnan, genetic characteristics and transmitted drug resistance (TDR) should be further investigated among the recently infected population. Among 2828 HIV-positive samples newly reported in the first quarter of 2014, 347 were identified as recent infections with BED-captured enzyme immunoassay (CEIA). Of them, 291 were successfully genotyped and identified as circulating recombinant form (CRF)08_BC (47.4%), unique recombinant forms (URFs) (18.2%), CRF01_AE (15.8%), CRF07_BC (14.4%), subtype C (2.7%), CRF55_01B (0.7%), subtype B (0.3%) and CRF64_BC (0.3%). CRF08_BC and CRF01_AE were the predominant genotypes among heterosexual and homosexual infections, respectively. CRF08_BC, URFs, CRF01_AE and CRF07_BC expanded with higher prevalence in central and eastern Yunnan. The recent common ancestor of CRF01_AE, CRF07_BC and CRF08_BC dated back to 1983.1, 1992.1 and 1989.5, respectively. The effective population sizes (EPS) for CRF01_AE and CRF07_BC increased exponentially during 1991–1999 and 1994–1999, respectively. The EPS for CRF08_BC underwent two exponential growth phases in 1994–1998 and 2001–2002. Lastly, TDR-associated mutations were identified in 1.8% of individuals. These findings not only enhance our understanding of HIV-1 evolution in Yunnan but also have implications for vaccine design and patient management strategies.
We investigate the class of bipartite Borel graphs organized by the order of Borel homomorphism. We show that this class is unbounded by finding a jump operator for Borel graphs analogous to a jump operator of Louveau for Borel equivalence relations. The proof relies on a nonseparation result for iterated Fréchet ideals and filters due to Debs and Saint Raymond. We give a new proof of this fact using effective descriptive set theory. We also investigate an analogue of the Friedman-Stanley jump for Borel graphs. This analogue does not yield a jump operator for bipartite Borel graphs. However, we use it to answer a question of Kechris and Marks by showing that there is a Borel graph with no Borel homomorphism to a locally countable Borel graph, but each of whose connected components has a countable Borel coloring.
Athetis lepigone (Möschler) (Lepidoptera: Noctuidae) is a new outbreak pest in China. Consequently, it is unclear whether the emergence and spread of the outbreak of this pest are triggered by rapid in situ population size increases in each outbreak area, or by immigrants from a potential source area in China. In order to explore the outbreak process of this pest through a population genetics approach, we developed ten novel polymorphic expressed sequence tags (EST)-derived microsatellites. These new microsatellites had moderately high levels of polymorphism in the tested population. The number of alleles per locus ranged from 3 to 19, with an average of 8.6, and the expected heterozygosity ranged from 0.269 to 0.783. A preliminary population genetic analysis using these new microsatellites revealed a lack of population genetic structure in natural populations of A. lepigone. The estimates of recent migration rate revealed strong gene flow among populations. In conclusion, our study developed the first set of EST-microsatellite markers and shed a new light on the population genetic structure of this pest in China.
The mixing of unfamiliar sows at weaning forces the establishment of dominance hierarchies, which frequently involves aggression (Kay et al, 1999). The objective of this study was to determine whether different stocking densities and pen shapes would reduce the incidence of aggression and levels of skin damage. The ultimate aim was to design a mixing pen which could be used to enhance the welfare of groups of newly-weaned sows.
The mixing of unfamiliar sows at weaning leads to aggression whilst dominance hierarchies within the group are established (Kay et al, 1999). The objective of this study was to determine whether the presence of a boar would reduce the incidence of aggression and level of skin damage of newly mixed sows. The overall aim of the project was to improve welfare by designing a suitable strategy for mixing groups of newly-weaned sows
Weaning is associated with a dramatic change in the nutritional status of young animals, and many neonates experience a lag in their normal trajectory of growth post-weaning because they have little experience of ingesting solid food. In the wild, animals are able to learn which foods are ‘safe’ through the mammary transfer of volatile flavours present in the maternal diet. This mechanism could be harnessed in a commercial environment by the use of flavour imprinting, a technique where a characteristic flavour is included both in the maternal and weanling's diet (for pilot data see Campbell, 1976). The use of this method could be associated with considerable increases in the profitability of animal production, however, the whole area is poorly understood. The objective of this experiment was to enhance our understanding of the effect of flavour imprinting on the acceptability of solid food, and hence our ability to predict the diet selection and food intake of newly weaned animals.
Recent years have seen several new and important applications of matching procedures in practical applications, including school assignments in New York and Boston and new designs for life-saving organ exchanges. The mechanisms that have been adopted, and sometimes even the runner-up mechanisms, are stable matching mechanisms. Recall that stable matches are matches with the property that no individual can do better by staying unmatched and no pair can both do better by matching to one another. Since pairs are the only significant coalitions in this theory, stable matches are a kind of core allocation. Stable matching mechanisms are direct mechanisms that select a stable match with respect to the reported preferences; the definition does not require that the mechanism be incentive-compatible.
Evidence suggesting that stable matching mechanisms remain in use long after unstable mechanisms have been abandoned is found both in empirical studies (Roth and Xing 1994) and in laboratory experiments (Kagel and Roth 2000). If stable mechanisms actually lead to stable matches, then these mechanisms have the important practical advantage that no couple that would prefer to renege after the mechanism is run in favor of some alternative pairing, because no such agreement can be better for both members of the couple than the outcome of a stable matching mechanism. Even for a stable mechanism, with enough uncertainty, there might be pairs that could increase their expected payoffs by matching in advance, but the resulting unstable match would be vulnerable to defections by parties who might find a better alternative.
A similar analysis applies to core-selecting auction mechanisms. An individually rational outcome is in the core of an auction game if and only if there is no group of bidders who would strictly prefer an alternative deal that is also strictly better for seller. Consequently, an auction mechanism that delivers core allocations has the advantages that there is no individual or group that would want to renege after the auction is run in favor of some allocation that is feasible for it and any non-core agreement made before the auction is vulnerable to defections, as the seller attracts better offers afterwards.
Many snow models have been developed for various applications such as hydrology, global atmospheric circulation models and avalanche forecasting. The degree of complexity of these models is highly variable, ranging from simple index methods to multi-layer models that simulate snow-cover stratigraphy and texture. In the framework of the Snow Model Intercomparison Project (SnowMIP), 23 models were compared using observed meteorological parameters from two mountainous alpine sites. The analysis here focuses on validation of snow energy-budget simulations. Albedo and snow surface temperature observations allow identification of the more realistic simulations and quantification of errors for two components of the energy budget: the net short- and longwave radiation. In particular, the different albedo parameterizations are evaluated for different snowpack states (in winter and spring). Analysis of results during the melting period allows an investigation of the different ways of partitioning the energy fluxes and reveals the complex feedbacks which occur when simulating the snow energy budget. Particular attention is paid to the impact of model complexity on the energy-budget components. The model complexity has a major role for the net longwave radiation calculation, whereas the albedo parameterization is the most significant factor explaining the accuracy of the net shortwave radiation simulation.
The WAIS (West Antarctic Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending 50 m above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity. The climate record developed from this core is therefore likely to be continuous and robust. Measured grain-growth rates, recrystallization characteristics, and grain-size response at climate transitions fit within current understanding. Significant impurity control on grain size is indicated from correlation analysis between impurity loading and grain size. Bubble-number densities and bubble sizes and shapes are presented through the full extent of the bubbly ice. Where bubble elongation is observed, the direction of elongation is preferentially parallel to the trace of the basal (0001) plane. Preferred crystallographic orientation of grains is present in the shallowest samples measured, and increases with depth, progressing to a vertical-girdle pattern that tightens to a vertical single-maximum fabric. This single-maximum fabric switches into multiple maxima as the grain size increases rapidly in the deepest, warmest ice. A strong dependence of the fabric on the impurity-mediated grain size is apparent in the deepest samples.
During 2016 February, CSIRO Astronomy and Space Science and the Max-Planck-Institute for Radio Astronomy installed, commissioned, and carried out science observations with a phased array feed receiver system on the 64-m diameter Parkes radio telescope. Here, we demonstrate that the phased array feed can be used for pulsar observations and we highlight some unique capabilities. We demonstrate that the pulse profiles obtained using the phased array feed can be calibrated and that multiple pulsars can be simultaneously observed. Significantly, we find that an intrinsic polarisation leakage of −31 dB can be achieved with a phased array feed beam offset from the centre of the field of view. We discuss the possibilities for using a phased array feed for future pulsar observations and for searching for fast radio bursts with the Parkes and Effelsberg telescopes.