The missing links in the BGP-based AS connectivity maps

PAM2003 - The Passive and Active Measurement Workshop(http://www.pam2003.org), San Diego, USA, April 2003PAM2003 - The Passive and Active Measurement Workshop(http://www.pam2003.org), San Diego, USA, April 2003PAM2003 - The Passive and Active Measurement Workshop(http://www.pam2003.org), San Diego, USA, April 2003A number of recent studies of the Internet topology at the autonomous systems level (AS graph) are based on the BGP-based AS connectivity maps (original maps). The so-called extended maps use additional data sources and contain more complete pictures of the AS graph. In this paper, we compare an original map, an extended map and a synthetic map generated by the Barabasi-Albert model. We examine the recently reported rich-club phenomenon, alternative routing paths and attack tolerance. We point out that the majority of the missing links of the original maps are the connecting links between rich nodes (nodes with large numbers of links) of the extended maps. We show that the missing links are relevant because links between rich nodes can be crucial for the network structure

Antennal transcriptome profiles of anopheline mosquitoes reveal human host olfactory specialization in Anopheles gambiae

BACKGROUND: Two sibling members of the Anopheles gambiae species complex display notable differences in female blood meal preferences. An. gambiae s.s. has a well-documented preference for feeding upon human hosts, whereas An. quadriannulatus feeds on vertebrate/mammalian hosts, with only opportunistic feeding upon humans. Because mosquito host-seeking behaviors are largely driven by the sensory modality of olfaction, we hypothesized that hallmarks of these divergent host seeking phenotypes will be in evidence within the transcriptome profiles of the antennae, the mosquito's principal chemosensory appendage. RESULTS: To test this hypothesis, we have sequenced antennal mRNA of non-bloodfed females from each species and observed a number of distinct quantitative and qualitative differences in their chemosensory gene repertoires. In both species, these gene families show higher rates of sequence polymorphisms than the overall rates in their respective transcriptomes, with potentially important divergences between the two species. Moreover, quantitative differences in odorant receptor transcript abundances have been used to model potential distinctions in volatile odor receptivity between the two sibling species of anophelines. CONCLUSION: This analysis suggests that the anthropophagic behavior of An. gambiae s.s. reflects the differential distribution of olfactory receptors in the antenna, likely resulting from a co-option and refinement of molecular components common to both species. This study improves our understanding of the molecular evolution of chemoreceptors in closely related anophelines and suggests possible mechanisms that underlie the behavioral distinctions in host seeking that, in part, account for the differential vectorial capacity of these mosquitoes

Ensembles related to the rich-club coefficient for non-evolving networks

15 pages, 7 figures15 pages, 7 figures15 pages, 7 figuresIn complex networks the rich nodes are the subset of nodes with high degree. These well connected nodes tend to dominate the organisation of the network's structure. In non-evolving networks, a reference network has been used to detect if the connectivity between the rich nodes is due to chance or caused by an unknown mechanism. Chance is represented as a reference network obtained from an ensemble of networks. When compared with the original network the reference network discounts suggests the existence of a well connected rich club beyond structural constraints. Here we revise some of the properties of the ensemble obtained by conserving only the degree distribution and introduce two new reference networks to study the importance of the rich nodes as organisers of the network structure. The first reference network is obtained from an ensemble of networks where all the members of the ensemble have the same rich--club coefficient. The reference network obtained from the ensemble is assortative. We propose that this reference network can be used to study networks where assortativness is a fundamental property, a common case in many social networks. The second reference network is obtained from an ensemble where the members of the ensemble all have the same probability degree distribution and rich-club coefficient. The reference network obtained from this ensemble has a very similar structure to the original network. This ensemble can be used to quantify correlations between the rich nodes and pinpoint which links are the backbone of the network's structure

Endothelin receptor a blockade is an ineffective treatment for adriamycin nephropathy

Endothelin is a vasoconstricting peptide that plays a key role in vascular homeostasis, exerting its biologic effects via two receptors, the endothelin receptor A (ETA) and endothelin receptor B (ETB). Activation of ETA and ETB has opposing actions, in which hyperactive ETA is generally vasoconstrictive and pathologic. Selective ETA blockade has been shown to be beneficial in renal injuries such as diabetic nephropathy and can improve proteinuria. Atrasentan is a selective pharmacologic ETA blocker that preferentially inhibits ETA activation. In this study, we evaluated the efficacy of ETA blockade by atrasentan in ameliorating proteinuria and kidney injury in murine adriamycin nephropathy, a model of human focal segmental glomerulosclerosis. We found that ETA expression was unaltered during the course of adriamycin nephropathy. Whether initiated prior to injury in a prevention protocol (5 mg/kg/day, i.p.) or after injury onset in a therapeutic protocol (7 mg/kg or 20 mg/kg three times a week, i.p.), atrasentan did not significantly affect the initiation and progression of adriamycin-induced albuminuria (as measured by urinary albumin-to-creatinine ratios). Indices of glomerular damage were also not improved in atrasentan-treated groups, in either the prevention or therapeutic protocols. Atrasentan also failed to improve kidney function as determined by serum creatinine, histologic damage, and mRNA expression of numerous fibrosis-related genes such as collagen-I and TGF-β1. Therefore, we conclude that selective blockade of ETA by atrasentan has no effect on preventing or ameliorating proteinuria and kidney injury in adriamycin nephropathy. © 2013 Tan et al

Increased collagen synthesis rate during wound healing in muscle

Wound healing in muscle involves the deposition of collagen, but it is not known whether this is achieved by changes in the synthesis or the degradation of collagen. We have used a reliable flooding dose method to measure collagen synthesis rate in vivo in rat abdominal muscle following a surgical incision. Collagen synthesis rate was increased by 480% and 860% on days 2 and 7 respectively after surgery in the wounded muscle compared with an undamaged area of the same muscle. Collagen content was increased by approximately 100% at both day 2 and day 7. These results demonstrate that collagen deposition during wound healing in muscle is achieved entirely by an increase in the rate of collagen synthesis

An Introduction to SPEARS (Spectrum Education Awareness)

This presentation provides an overview of the SPectrum Education AwaRenesS (SPEARS) initiative developed by the NASA Spectrum Office under HEO/SCaN. SPEARS is a strategic initiative that is comprised of fourteen (14) activities/tasks targeted for various stakeholders within and external to NASA and from the spectrum and non-spectrum communities. These activities will also facilitate fostering partnerships and enhance the regulatory and policy understanding with international spectrum regulators and other space agencies. Further, SPEARS will institute several activities geared to promote spectrum management and to gain the interest of the next and future generations of spectrum managers, through Science, Technology, Engineering, and Mathematics (STEM) outreach

Protecting Future Personal Computing: Challenging Traditional Network Security Models

The Internet is a notoriously two-way street. If multiple computers can communicate sensitive data across the internet, malicious entities can access the network and collect this data also. The range and number of connected devices is increasing dramatically and with this expansion so is the security risk. Collection of ever rising quantities of data, especially sensitive and personal data, raises many challenges and questions about the suitability of current security. The key problem our research investigates is how we can adapt traditional security models to enhance it both current and future deployment. The work is not aimed to replace existing security although it builds upon it to complement it and enhance existing methods. We utilise the timeliness of the Internet of Things as a focus to develop and experiment with our work. In this paper we present our novel framework and introduce our initial work to prove the concept is feasible. Our initial results are encouraging as to the impact the framework could have on future security. Keywords- Network security; mobile security; smartphone; malware detection; in-network; Collaborative; Internet of Thing

Lightweight Forensics Application: Lightweight Approach to Securing Mobile Devices

Physical objects with the addition of sensors, actuators and a connection to the internet form devices which can collect, process and communicate data to each other. Devices may not have been designed with connectivity in mind and adding it as an afterthought is problematic. This provides a significant technical challenge concerning securing the devices, as they are all of a sudden open to a wide range of attacks whilst providing more opportunities for malicious users and increases the chances of device compromise. The key aim of this research is to address limitations in current security solutions on mobile devices by defining a novel approach which will sustain future advances in mobile technology. Using combined security techniques our proposed solution will work with existing security technology to create a more effective and successful security implementation that will be suitable for a wide range of mobile devices. Keywords- Lightweight security; mobile device; smartphone; digital forensics; malware detection; in-network; Collaborative; Internet of Thing

Rapid publication-ready MS-Word tables for one-way ANOVA

© 2014, Assaad et al.; licensee Springer. Conclusions: Our new and user-friendly software to perform statistical analysis and generate publication-ready MS-Word tables for one-way ANOVA are expected to facilitate research in agriculture, biomedicine, and other fields of life sciences.Background: Statistical tables are an important component of data analysis and reports in biological sciences. However, the traditional manual processes for computation and presentation of statistically significant results using a letter-based algorithm are tedious and prone to errors.Results: Based on the R language, we present two web-based software for individual and summary data, freely available online, at http://shiny.stat.tamu.edu:3838/hassaad/Table_report1/ and http://shiny.stat.tamu.edu:3838/hassaad/SumAOV1/, respectively. The software are capable of rapidly generating publication-ready tables containing one-way analysis of variance (ANOVA) results. No download is required. Additionally, the software can perform multiple comparisons of means using the Duncan, Student-Newman-Keuls, Tukey Kramer, and Fisher’s least significant difference (LSD) tests. If the LSD test is selected, multiple methods (e.g., Bonferroni and Holm) are available for adjusting p-values. Using the software, the procedures of ANOVA can be completed within seconds using a web-browser, preferably Mozilla Firefox or Google Chrome, and a few mouse clicks. Furthermore, the software can handle one-way ANOVA for summary data (i.e. sample size, mean, and SD or SEM per treatment group) with post-hoc multiple comparisons among treatment means. To our awareness, none of the currently available commercial (e.g., SPSS and SAS) or open-source software (e.g., R and Python) can perform such a rapid task without advanced knowledge of the corresponding programming language