725 research outputs found
High density p-type Bi0.5Sb1.5Te3 nanowires by electrochemical templating through ion-track lithography
High density p-type Bi0.5Sb1.5Te3 nanowire arrays are produced by a combination of electrodeposition and ion-track lithography technology. Initially, the electrodeposition of p-type wBi(0.5)Sb(1.5)Te(3) films is investigated to find out the optimal conditions for the deposition of nanowires. Polyimide-based Kapton foils are chosen as a polymer for ion track irradiation and nanotemplating Bi0.5Sb1.5Te3 nanowires. The obtained nanowires have average diameters of 80 nm and lengths of 20 mu m, which are equivalent to the pore size and thickness of Kapton foils. The nanowires exhibit a preferential orientation along the {110} plane with a composition of 11.26 at.% Bi, 26.23 at.% Sb, and 62.51 at.% Te. Temperature dependence studies of the electrical resistance show the semiconducting nature of the nanowires with a negative temperature coefficient of resistance and band gap energy of 0.089 +/- 0.006 eV
Prediction-based classification for longitudinal biomarkers
Assessment of circulating CD4 count change over time in HIV-infected subjects
on antiretroviral therapy (ART) is a central component of disease monitoring.
The increasing number of HIV-infected subjects starting therapy and the limited
capacity to support CD4 count testing within resource-limited settings have
fueled interest in identifying correlates of CD4 count change such as total
lymphocyte count, among others. The application of modeling techniques will be
essential to this endeavor due to the typically nonlinear CD4 trajectory over
time and the multiple input variables necessary for capturing CD4 variability.
We propose a prediction-based classification approach that involves first stage
modeling and subsequent classification based on clinically meaningful
thresholds. This approach draws on existing analytical methods described in the
receiver operating characteristic curve literature while presenting an
extension for handling a continuous outcome. Application of this method to an
independent test sample results in greater than 98% positive predictive value
for CD4 count change. The prediction algorithm is derived based on a cohort of
HIV-1 infected individuals from the Royal Free Hospital, London who
were followed for up to three years from initiation of ART. A test sample
comprised of individuals from Philadelphia and followed for a similar
length of time is used for validation. Results suggest that this approach may
be a useful tool for prioritizing limited laboratory resources for CD4 testing
after subjects start antiretroviral therapy.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS326 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Fabrication of (Mn,Co)3O4 Surface Coatings onto Alloy Substrates
Ferritic stainless steels are promising candidates for IT-SOFC interconnect applications due to their low cost and resistance to oxidation at SOFC operating temperatures. However, several challenges remain, including long term electrical conductivity and surface stability under interconnect exposure conditions and chromia scale evaporation. One means of extending interconnect lifetime and improving performance is to apply a protective coating, such as (Mn,Co)3O4 spinel, to the cathode side of the interconnect. These coatings have proven effective in reducing scale growth kinetics and Cr volatility. This report describes several procedures developed at PNNL for fabricating (Mn,Co)3O4 spinel coatings onto ferritic stainless steels
First Report of Phaeoacremonium minimum Associated with Grapevine Trunk Diseases in China
Grapevine trunk diseases (GTDs) are a complex of diseases that strongly affect grape productivity, wine quality, and vineyard longevity worldwide. GTDs occur in diverse regions, and in some areas disease agents are present in up to 100% of vines (Pintos et al. 2018). Recently, species belonging to Botryosphaeria and Diaporthe were identified as pathogens associated with GTDs in China (Dissanayake et al. 2015; Yan et al. 2013). During 2017 to 2018, interveinal leaf necrosis and wood white decay surrounded by brown necrosis in longitudinal section and black spots in cross section were observed in several grapevines (Cabernet) in Huailai County, Hebei Province, China. Disease incidence was up to 2 to 3% of the vineyard. Diseased samples (whole trunk and roots of 19-year-old vines) were collected and taken to the laboratory. Woody samples were cut into small chips, surface sterilized in 1.5% NaOCl for 3 min followed by 70% ethanol for 30 s, and rinsed three times with sterile distilled water (SDW). Once the samples were dried, they were placed onto PDA plates amended with ampicillin (0.1 g/liter). Plates were incubated at 25Ā°C under dark conditions. After 14 days of incubation, hyphal tips of fungi growing from wood pieces were transferred onto new PDA plates and incubated until they produced conidia. One type of colony was consistently isolated from the discolored tissue, with honey brown mycelium, and producing a yellow pigment on PDA. Conidia were ellipsoid to allantoid, 3.8 to 6.2 Ī¼m long, and 1.6 to 3.2 Ī¼m wide (n = 50). Morphologically these isolates resembled species belonging to Phaeoacremonium (Mostert et al. 2006). For species confirmation, genomic DNA of three representative isolates (JZB3190001, JZB3190003, and JZB3190005) was extracted. PCR amplification was performed using two phylogenetic markers (actin and Ī²-tubulin) amplified with primers ACT-513F/ACT-783R (Carbone and Kohn 1999) and T1/Bt2b (Glass and Donaldson 1995). The sequences obtained were deposited in GenBank under the accession numbers MK994188 to MK994193. Phylogenetic analysis was conducted using maximum likelihood in RAxML, which was accomplished using RAxML-HPC2 on XSEDE in the CIPRES Science Gateway platform (http://www.phylo.org/). In the phylogenetic tree, the isolates from the present study clustered together with Phaeoacremonium minimum (CBS 246.91), with 100 bootstrap values. Based on morphological characters and phylogenetic results, the species isolated in this study was identified as P. minimum (Tul. & C. Tul.) D. Gramaje, L. Mostert & Crous (Gramaje et al. 2015). The pathogenicity test was conducted on healthy, 2-month-old, rooted 'Furcal' grapevines that were grown in an inoculation chamber. Roots were washed using flow water and rinsed with SDW. The ends of SDW-treated roots (roughly 1 cm) were cut with sterilized scissors, and the roots and trunk base of Furcal vines were dipped in a 10ā¶/ml P. minimum spore suspension for 30 min. Inoculated plants were immediately planted in individual pots, and 10 ml of spore suspension was added to the soil per pot. SDW was used as a control. Two P. minimum isolates (JZB3190001 and JZB3190003) were used to do the pathogenicity test, and 10 plants were inoculated with each isolate and the control water. Temperature of the inoculation chamber was controlled between 24 and 25Ā°C, and humidity was maintained at 60%. After 114 days of inoculation, the inoculated plants developed black necrosis at the base of wood but did not show leaf necrosis, whereas the control plants showed no symptoms both in wood and leaves. Koch's postulates were confirmed by reisolating and identification based on cultural and morphological characters of the inoculated isolates. To our knowledge, this is the first report of P. minimum associated with GTDs in China. The results of this study will enhance the capability of controlling GTDs in China by correct identification of the causal organism
Multi-band remote sensing based retrieval model and 3D analysis of water depth in Hulun Lake, China
Hulun Lake, a large lake located on the cold and arid Hulunbeir grassland in the Inner
Mongolia Autonomous Region, is the fifth largest in China and the largest in the north of
the country. However, the information on the lakeās characteristics (e.g., water depth versus
surface area) is scarce in literature. Based on the lakeās physiographic features, this study
developed and used a model that merges the sunlight reflection band with the thermal
infrared radiation band to simulate the lakeās characteristics. The model verification and
error analysis indicated an optimal model structure of logarithm. Thus, this logarithmic
model was selected to analyze the spectral data. The results indicated that the model did a
good job in reproducing observed water depths and accurately predicted the depths on 24
September 2007. This showed that this model can be reliably applied to the cold and arid
region. Subsequently, the results were used to generate a triangular irregular network (TIN)
model, which in turn was used to compute the functional relations between water level,
surface area, and volume. The correlation between water level and volume is superior to
that between water level and area. The regression equation developed in this study can be
used to estimate the volume when water elevation is knowninfo:eu-repo/semantics/publishedVersio
Recommended from our members
Radiocarbon Dating of Charcoal and Bone Collagen Associated with Early Pottery at Yuchanyan Cave, Hunan Province, China
Yuchanyan Cave in Daoxian County, Hunan Province (People's Republic of China), yielded fragmentary remains of 2 or more ceramic vessels, in addition to large amounts of ash, a rich animal bone assemblage, cobble and flake artifacts, bone tools, and shell tools. The artifacts indicate that the cave was a Late Paleolithic foragers' camp. Here we report on the radiocarbon ages of the sediments based on analyses of charcoal and bone collagen. The best-preserved charcoal and bone samples were identified by prescreening in the field and laboratory. The dates range from around 21,000 to 13,800 cal BP. We show that the age of the ancient pottery ranges between 18,300 and 15,430 cal BP. Charcoal and bone collagen samples located above and below one of the fragments produced dates of around 18,000. These ceramic potsherds therefore provide some of the earliest evidence for pottery making in China.Anthropolog
Recommended from our members
Importance of different parameterization changes for the updated dust cycle modeling in the Community Atmosphere Model (version 6.1)
The Community Atmosphere Model (CAM6.1), the atmospheric component of the Community Earth System Model (CESM; version 2.1), simulates the life cycle (emission, transport, and deposition) of mineral dust and its interactions with physio-chemical components to quantify the impacts of dust on climate and the Earth system. The accuracy of such quantifications relies on how well dust-related processes are represented in the model. Here we update the parameterizations for the dust module, including those on the dust emission scheme, the aerosol dry deposition scheme, the size distribution of transported dust, and the treatment of dust particle shape. Multiple simulations were undertaken to evaluate the model performance against diverse observations, and to understand how each update alters the modeled dust cycle and the simulated dust direct radiative effect. The modelāobservation comparisons suggest that substantially improved model representations of the dust cycle are achieved primarily through the new more physically-based dust emission scheme. In comparison, the other modifications induced small changes to the modeled dust cycle and modelāobservation comparisons, except the size distribution of dust in the coarse mode, which can be even more influential than that of replacing the dust emission scheme. We highlight which changes introduced here are important for which regions, shedding light on further dust model developments required for more accurately estimating interactions between dust and climate.</p
- ā¦