1,707 research outputs found
Implementation of Epidemic Routing with IP Convergence Layer in ns-3
We present the Epidemic routing protocol implementation in ns-3. It is a
full-featured DTN protocol in that it supports the message abstraction and
store-and-haul behavior. We compare the performance of our Epidemic routing
ns-3 implementation with the existing implementation of Epidemic in the ONE
simulator, and discuss the differences
Sequentially evaporated thin Y-Ba-Co-O superconducting films on microwave substrates
The development of high T sub c superconducting thin films on various microwave substrates is of major interest in space electronic systems. Thin films of YBa2Cu3O(7-Delta) were formed on SrTiO3, MgO, ZrO2 coated Al2O3, and LaAlO3 substrates by multi-layer sequential evaporation and subsequent annealing in oxygen. The technique allows controlled deposition of Cu, BaF2 and Y layers, as well as the ZrO buffer layers, to achieve reproducibility for microwave circuit fabrication. The three layer structure of Cu/BaF2/Y is repeated a minimum of four times. The films were annealed in an ambient of oxygen bubbled through water at temperatures between 850 C and 900 C followed by slow cooling (-2 C/minute) to 450 C, a low temperature anneal, and slow cooling to room temperature. Annealing times ranged from 15 minutes to 5 hrs. at high temperature and 0 to 6 hr. at 450 C. Silver contacts for four probe electrical measurements were formed by evaporation followed with an anneal at 500 C. The films were characterized by resistance-temperature measurements, energy dispersive X-ray spectroscopy, X-ray diffraction, and scanning electron microscopy. Critical transition temperatures ranged from 30 K to 87 K as a function of the substrate, composition of the film, thicknesses of the layers, and annealing conditions. Microwave ring resonator circuits were also patterned on these MgO and LaAlO3 substrates
Stabilization of the Ī³-Sn phase in tin nanoparticles and nanowires
Structures of Sn nanoparticles and nanowires are studied using density
functional theory in conjunction with thermodynamic considerations. Besides
the low-temperature Ī± and room-temperature Ī² phases, the high-temperature Ī³
phase is considered. Results show that at ambient temperatures for sizes
smaller than 50ānm, metallic Ī²- and Ī³-Sn nanoparticles are more stable than
semimetallic Ī±-Sn ones because of their lower surface energies. Moreover, very
small Sn nanostructures, exemplified by nanowires, are expected to exhibit the
Ī³ phase even at 0āK
Mitochondrial hyperpolarization in iPSC-derived neurons from patients of FTDP-17 with 10+16 MAPT mutation leads to oxidative stress and neurodegeneration
Tau protein inclusions are a frequent hallmark of a variety of neurodegenerative disorders. The 10+16 intronic mutation in MAPT gene, encoding tau, causes frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), by altering the splicing of the gene and inducing an increase in the production of 4R tau isoforms, which are more prone to aggregation. However, the molecular mechanisms linking increased 4R tau to neurodegeneration are not well understood. Here, we have used iPSC-derived neurons from patients of FTDP-17 carrying the 10+16 mutation to study the molecular mechanisms underlying neurodegeneration. We show that mitochondrial function is altered in the neurons of the patients. We found that FTDP-17 neurons present an increased mitochondrial membrane potential, which is partially maintained by the F1Fo ATPase working in reverse mode. The 10+16 MAPT mutation is also associated with lower mitochondrial NADH levels, partially supressed complex I-driven respiration, and lower ATP production by oxidative phosphorylation, with cells relying on glycolysis to maintain ATP levels. Increased mitochondrial membrane potential in FTDP-17 neurons leads to overproduction of the ROS in mitochondria, which in turn causes oxidative stress and cell death. Mitochondrial ROS overproduction in these cells is a major trigger for neuronal cell death and can be prevented by mitochondrial antioxidants
Comparing The Effect Of Overspeed Training On NCAA Division III Lacrosse Athletes
Please view abstract in the attached PDF file
Balanced sensitivity and specificity on unbalanced data using support vector machine re-thresholding
Support vector machine (SVM) classifiers use multivariate patterns to separate two groups by a hyperplane with maximal margin. This strategy tends to obtain good generalisation accuracy on even very high dimensional applications. However, SVMs are not well suited to unbalanced data with very different numbers of cases in each group. In this work we implement a properly cross-validated method for altering the SVM threshold (also known as the bias or cut-point) to re-balance the sensitivity and specificity
Cardiovascular safety of growth hormone treatment in Noonan syndrome: real-world evidence
OBJECTIVE: To assess cardiovascular (CV) safety of growth hormone (GH) treatment in patients with Noonan syndrome (NS) in clinical practice. DESIGN: Two observational, multicentre studies (NordiNetĀ® IOS and the ANSWER Program) evaluating long-term effectiveness and safety of GH in >38,000 paediatric patients, of which 421 had NS. METHODS: Serious adverse events, serious adverse reactions (SARs), and non-serious adverse reactions (NSARs) were reported by the treating physicians. CV comorbidities at baseline and throughout the studies were also recorded. RESULTS: The safety analysis set comprised 412 children with NS (29.1% females), with a mean (standard deviation) baseline age of 9.29 (3.88) years, treated with an average GH dose of 0.047 (0.014) mg/kg/day during childhood. CV comorbidities at baseline were reported in 48 (11.7%), most commonly pulmonary valve stenosis and atrial septal defects. Overall, 22 (5.3%) patients experienced 34 safety events. The most common were the NSARs: headache (eight events in seven patients) and arthralgia (five events in three patients). Two SARs occurred in one patient (brain neoplasm and metastases to spine). No CV safety events were recorded in patients with NS. Five CV comorbidities in five patients were reported after initiation of GH treatment: three cases of unspecified CV disease, one ruptured abdominal aortic aneurysm and one pulmonary valve stenosis. CONCLUSIONS: GH treatment had a favourable safety profile in patients with NS, including those with CV comorbidities. Prospective studies are warranted to systematically assess the safety of GH treatment in patients with Noonan syndrome and CV disease
Rapid Communication: Genetic Linkage and Physical Mapping of the Porcine Androgen Receptor (AR) Gene
Source and Description of Primers. Primers were designed from published bovine and human androgen receptor (AR) sequences (GenBank accession number Z75315 and M27430, respectively). These primers were used to obtain a porcine sequence (submitted to GenBank: accession number AF079783). A total of 247 bp out of the entire 793-bp PCR product shared 90.3% identity with sections of exons 7 and 8 of the human AR gene. Porcine specific primers (AR-3 and AR-4) were then designed to amplify a 160-bp fragment in intron 7 of the AR gene region from porcine genomic DNA
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