Bottom‐Up Tailoring of Plasmonic Nanopeapods Making Use of the Periodical Topography of Carbon Nanocoil Templates

Au nanoparticle chains embedded in helical Al₂O₃ nanotubes (“nanopeapods”) are synthesized by annealing carbon nanocoils coated with Au by sputtering and Al₂O₃ by atomic layer deposition. Regular spacing between nanoparticles with a sharp size distribution is achieved by fragmentation of the Au coating in agreement with the pitch of the nanocoils arising from three‐dimensional periodical topography of the carbon nanocoil templates. A strong plasmonic resonance behavior of the fabricated nanopeapods manifests itself in confocal laser scanning microscopy by a clear polarization contrast at red wavelengths, which is absent in the blue. Numerical simulations confirm an incisive resonance enhancement for longitudinal polarization and suggest the nanopeapods as promising candidates for highly efficient, ultrathin waveguides. The waveguiding properties of the nanopeapods are investigated by electron energy‐loss spectroscopy and energy‐filtered TEM imaging.     

A second look at Faster,Better, Cheaper

“Faster, Better, Cheaper” (FBC) was a systems development methodology used by NASA in the 1990s. While usually a deprecated practice, we find that, with certain caveats, it is a viable approach. To determine this we utilized a stochastic AI tool to determine the behavior of FBC for several case studies. In these case studies we compare results of using FBC with that of other optimization policies. In our tests, FBC is as advantageous a policy to use with projects as other policies, while avoiding their apparent downfalls.     

Efficient data dissemination in cooperative vehicular networks

Vehicular networks are drawing the attention of both research community and automotive industry because they provide intelligent transportation systems as well as drivers and passengers’ assistant services. However, the industrialization of such networks faces a number of challenges, in particular, the high cost of the infrastructure to deploy. To overcome this problem, an effective solution is to rely on cooperative vehicle‐to‐vehicle communication to minimize the deployed infrastructure. Because a large number of cooperative vehicle‐to‐vehicle applications are broadcasting by nature, we proposed an efficient dissemination protocol: Road‐Oriented Dissemination (ROD). ROD consists in two modules: (i) Optimized Distance Defer Transfer Module and (ii) Store‐and‐Forward Module. We compare our protocol with other dissemination protocols and analyze its performance by simulations, on‐road tests and analytically. Performance study shows interesting results of ROD compared with the other existing solutions. ROD is able to provide a low end‐to‐end delay, high delivery ratios, and a minimum bandwidth usage because only a limited number of vehicles are involved in the broadcast scheme. Copyright © 2011 John Wiley & Sons, Ltd.     

TILLING-by-Sequencing+ to Decipher Oil Biosynthesis Pathway in Soybeans: A New and Effective Platform for High-Throughput Gene Functional Analysis

Reverse genetic approaches have been widely applied to study gene function in crop species; however, these techniques, including gel-based TILLING, present low efficiency to characterize genes in soybeans due to genome complexity, gene duplication, and the presence of multiple gene family members that share high homology in their DNA sequence. Chemical mutagenesis emerges as a genetically modified-free strategy to produce large-scale soybean mutants for economically important traits improvement. The current study uses an optimized high-throughput TILLING by target capture sequencing technology, or TILLING-by-Sequencing⁺ (TbyS⁺), coupled with universal bioinformatic tools to identify population-wide mutations in soybeans. Four ethyl methanesulfonate mutagenized populations (4032 mutant families) have been screened for the presence of induced mutations in targeted genes. The mutation types and effects have been characterized for a total of 138 soybean genes involved in soybean seed composition, disease resistance, and many other quality traits. To test the efficiency of TbyS⁺ in complex genomes, we used soybeans as a model with a focus on three desaturase gene families, GmSACPD, GmFAD2, and GmFAD3, that are involved in the soybean fatty acid biosynthesis pathway. We successfully isolated mutants from all the six gene family members. Unsurprisingly, most of the characterized mutants showed significant changes either in their stearic, oleic, or linolenic acids. By using TbyS⁺, we discovered novel sources of soybean oil traits, including high saturated and monosaturated fatty acids in addition to low polyunsaturated fatty acid contents. This technology provides an unprecedented platform for highly effective screening of polyploid mutant populations and functional gene analysis. The obtained soybean mutants from this study can be used in subsequent soybean breeding programs for improved oil composition traits.     

Extreme-value-theoretic estimation of local intrinsic dimensionality

This paper is concerned with the estimation of a local measure of intrinsic dimensionality (ID) recently proposed by Houle. The local model can be regarded as an extension of Karger and Ruhl’s expansion dimension to a statistical setting in which the distribution of distances to a query point is modeled in terms of a continuous random variable. This form of intrinsic dimensionality can be particularly useful in search, classification, outlier detection, and other contexts in machine learning, databases, and data mining, as it has been shown to be equivalent to a measure of the discriminative power of similarity functions. Several estimators of local ID are proposed and analyzed based on extreme value theory, using maximum likelihood estimation, the method of moments, probability weighted moments, and regularly varying functions. An experimental evaluation is also provided, using both real and artificial data.     

In situ nanoscale mapping of the chemical composition of surfaces and 3D nanostructures by photoelectron spectromicroscopy

We propose a novel approach to extract quantitative chemical maps of surfaces with nanoscale resolution, from the analysis of data from x-ray photoemission electron microscopy, which is a minimally invasive technique. Our formulation allows us to extract chemical maps from the raw data even in cases when not all experimental parameters are well known or controlled. We illustrate our concept by the analysis of a ternary alloy with a nanoscale pattern, to achieve chemical maps of unprecedented quality.     

Gold-catalyzed oxide nanopatterns for the directed assembly of Ge island arrays on Si

The heteroepitaxial growth of Ge on Au-patterned Si(001) is investigated using in situ spectromicroscopy. Patterning of a hydrogen-terminated Si surface with a square array of Au dots followed by brief exposure to air leads to the spontaneous, local oxidation of Si. The resulting oxide nanopattern limits the surface migration of Au during annealing up to 600 degrees C, resulting in complete preservation of the Au pattern. Subsequent deposition of Ge induces a redistribution of Au across the surface even as the oxide nanopattern persists. As a result, the oxide pattern drives the growth of Ge islands into an ordered assembly, while Au decorates the surfaces of the Ge islands and modifies their shape.     

Factors affecting virtual team performance in telecommunication support environment

Over the past two decades, many organizations have been taking advantage of globalization, outsourcing, and communication technology advances to enter new markets and compete wherever and whenever possible (Copeland, 2006). Telecommunication companies are among those companies that strive most to expand their customer base globally. Telecommunication industry is expected to grow on a worldwide basis to $2.7 trillion in 2017 (RCR Wireless, 2012). This global growth necessitates comparable expansion of support teams to service an expanded and distributed global customer base. Support function in the telecommunication industry has unique provisions and complex activities associated with troubleshooting customers’ networks. According to Williamson et al. (2004), troubleshooting customers’ networks involves complex activities such as making real-time traffic affecting decisions. Hence, identifying challenges that may face leaders in such complex and fast growing industry and factors that may influence the performance of support teams is critical. In addition, understanding the role and influence of leaders in virtual settings can help organizations in allocating resources and sorting teams’ priorities. In this study, we investigated factors that affect virtual team performance; factors considered include communication tools, cohesion and collaboration, leadership, trust, the location of team members and team size. One-hundred-twenty professionals in high-technology telecommunication industry participated in a survey to reveal the importance of how factors affecting virtual team performance. The findings indicated that support professionals perceived reliable communication tools and cohesion among team members as more significant performance factors than leadership.