Detailed Design of the Rigidizable Inflatable Get-Away-Special Experiment

The Rigidizable Inflatable Get-Away-Special Experiment is a Space Shuttle experiment that will study the effects of the zero-gravity space environment on the deployment and modal analysis of three inflatable and rigidizable tubes using a sub-Tg rigidization technique. In 2004, RIGEX was transitioned from the Space Shuttle\u27s Get-Away-Special (GAS) canister to its Canister for All Payload Ejections (CAPE), requiring several modifications to the design. The results of these modifications, along with further refinements made to previous efforts, combine to form the detailed design of the experiment. In addition to the design modifications, analyses were conducted to determine the containment capabilities of a shroud for the experiment, as well as to identify and implement potential improvements to the modal testing methods

Airline Networks: A Comparison of Hub-and-Spoke and Point-to-Point Systems

The disparity between the relative success of low-cost and network carriers since 2001 has often been attributed to the difference in route system architecture. This paper compares the economic and operational characteristics of point-to-point and hub-and-spoke route systems. It also argues that the emphasis placed on route structure obscures other differences in business models. Although U.S. low-cost-carriers are frequently characterized as operating point-to-point systems, few actually do so. As network airlines simplify their domestic products and the low-cost-carriers diversify theirs, the distinction between the two is rapidly fading

Seasonal-adjustment Based Feature Selection Method for Large-scale Search Engine Logs

Search engine logs have a great potential in tracking and predicting outbreaks of infectious disease. More precisely, one can use the search volume of some search terms to predict the infection rate of an infectious disease in nearly real-time. However, conducting accurate and stable prediction of outbreaks using search engine logs is a challenging task due to the following two-way instability characteristics of the search logs. First, the search volume of a search term may change irregularly in the short-term, for example, due to environmental factors such as the amount of media or news. Second, the search volume may also change in the long-term due to the demographic change of the search engine. That is to say, if a model is trained with such search logs with ignoring such characteristic, the resulting prediction would contain serious mispredictions when these changes occur. In this work, we proposed a novel feature selection method to overcome this instability problem. In particular, we employ a seasonal-adjustment method that decomposes each time series into three components: seasonal, trend and irregular component and build prediction models for each component individually. We also carefully design a feature selection method to select proper search terms to predict each component. We conducted comprehensive experiments on ten different kinds of infectious diseases. The experimental results show that the proposed method outperforms all comparative methods in prediction accuracy for seven of ten diseases, in both now-casting and forecasting setting. Also, the proposed method is more successful in selecting search terms that are semantically related to target diseases.Comment: The 25th ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD '19

A REVISED STONEMAN FOR DISTRIBUTED ADA SUPPORT ENVIRONMENTS

This paper extends the conceptual model of the "STONEMAN" document to more completely model the interfaces and protocols that exist in the Ada Programming Support Environment (APSE). A previous extension to the STONEMAN model is reviewed and critiqued, the guidelines for the APSE set forth in STONEMAN are reviewed, and an updated model is proposed. The new model is shown to meet the guidelines set forth in STONEMAN, and to include subsequent ideas as well. The new model is then applied to the problem of user communication with an APSE, and it is shown how the new model extends to include distributed APSEs as well as single host APSEs. The issue of security enforcement, as a necessary subset of dynamic verification, is also included in the new model

The distribution and evolutionary history of the PRP8 intein

BACKGROUND: We recently described a mini-intein in the PRP8 gene of a strain of the basidiomycete Cryptococcus neoformans, an important fungal pathogen of humans. This was the second described intein in the nuclear genome of any eukaryote; the first nuclear encoded intein was found in the VMA gene of several saccharomycete yeasts. The evolution of eukaryote inteins is not well understood. In this report we describe additional PRP8 inteins (bringing the total of these to over 20). We compare and contrast the phylogenetic distribution and evolutionary history of the PRP8 intein and the saccharomycete VMA intein, in order to derive a broader understanding of eukaryote intein evolution. It has been suggested that eukaryote inteins undergo horizontal transfer and the present analysis explores this proposal. RESULTS: In total, 22 PRP8 inteins have been detected in species from three different orders of euascomycetes, including Aspergillus nidulans and Aspergillus fumigatus (Eurotiales), Paracoccidiodes brasiliensis, Uncinocarpus reesii and Histoplasma capsulatum (Onygales) and Botrytis cinerea (Helotiales). These inteins are all at the same site in the PRP8 sequence as the original Cryptococcus neoformans intein. Some of the PRP8 inteins contain apparently intact homing endonuclease domains and are thus potentially mobile, while some lack the region corresponding to the homing endonuclease and are thus mini-inteins. In contrast, no mini-inteins have been reported in the VMA gene of yeast. There are several examples of pairs of closely related species where one species carries the PRP8 intein while the intein is absent from the other species. Bio-informatic and phylogenetic analyses suggest that many of the ascomycete PRP8 homing endonucleases are active. This contrasts with the VMA homing endonucleases, most of which are inactive. CONCLUSION: PRP8 inteins are widespread in the euascomycetes (Pezizomycota) and apparently their homing endonucleases are active. There is no evidence for horizontal transfer within the euascomycetes. This suggests that the intein is of ancient origin and has been vertically transmitted amongst the euascomycetes. It is possible that horizontal transfer has occurred between the euascomycetes and members of the basidiomycete genus Cryptococcus

Isolation, characterization, and genome sequence of the first representative of a novel class within the Chloroflexi that is abundant in some U.S. Great Basin hot springs and may play important roles in N and C cycling

A thermophilic, facultatively microaerophilic, heterotrophic bacterium, designated strain JAD2, was isolated from sediments of Great Boiling Spring (GBS), an ~80oC, circumneutral hot spring in the Great Basin GB). The strain grew anaerobically on yeast extract or peptone with an optimal growth temperature of 70-75oC. Growth was stimulated by addition of 0.01 atm O2 to the culture vessel headspace, but was inhibited by higher concentrations (0.2 atm). Cells of JAD2 formed non-motile filaments ranging from 10 to \u3e300 μm in length, which typically decreased in length during stationary phase. 16S rRNA gene-targeted pyrotag sequencing and clone library data suggest that close relatives of this isolate are prominent members of the sediment communities in GBS. Shotgun sequencing of the JAD2 genome produced an assembly consisting of ~3.2 Mbp with an average G+C content of 67.3%. Phylogenies inferred from the 16S rRNA gene and predicted amino acid sequences of various conserved proteins indicate that JAD2 is the first cultivated representative of the GAL35 group, a new class within the Chloroflexi. Predicted genes in the draft genome encoding a putative carbon monoxide dehydrogenase (coxMSL), nitrite reductase (nrfHA) and nitrous oxide reductase (nosZ) suggest that this isolate may play important roles in N and C cycling in GBS sediments