An Experimental Evaluation of the Computational Cost of a DPI Traffic Classifier

A common belief in the scientific community is that traffic classifiers based on deep packet inspection (DPI) are far more expensive in terms of computational complexity compared to statistical classifiers. In this paper we counter this notion by defining accurate models for a deep packet inspection classifier and a statistical one based on support vector machines, and by evaluating their actual processing costs through experimental analysis. The results suggest that, contrary to the common belief, a DPI classifier and an SVM-based one can have comparable computational costs. Although much work is left to prove that our results apply in more general cases, this preliminary analysis is a first indication of how DPI classifiers might not be as computationally complex, compared to other approaches, as we previously though

Comparing P2PTV Traffic Classifiers

Peer-to-Peer IP Television (P2PTV) applications represent one of the fastest growing application classes on the Internet, both in terms of their popularity and in terms of the amount of traffic they generate. While network operators require monitoring tools that can effectively analyze the traffic produced by these systems, few techniques have been tested on these mostly closed-source, proprietary applications. In this paper we examine the properties of three traffic classifiers applied to the problem of identifying P2PTV traffic. We report on extensive experiments conducted on traffic traces with reliable ground truth information, highlighting the benefits and shortcomings of each approach. The results show that not only their performance in terms of accuracy can vary significantly, but also that their usability features suggest different effective aspects that can be integrate

Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

BACKGROUND: Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. METHODS: Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. RESULTS: 1) CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2) this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3) CAP binding to HIV-1 virions impairs their infectivity; 4) these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. CONCLUSIONS: These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection

Africa in the click stream: audience metrics and foreign correspondents in africa

Digital technologies have transformed the relationship between news outlets, journalists and their audiences. Notably, editors can now monitor their websites and discern the exact news preferences of their readers. Research suggests that some editors are using this data to help them produce more popular, ‘click friendly’ content. To date, research on this phenomenon has focused on journalists working within newsrooms. This article adds to the literature by exploring the relationship of foreign correspondents in Africa with their audiences, and asks whether readership metrics are influencing the journalists’ selection and development of news stories. Drawing on 67 interviews with foreign correspondents in East and West Africa, the article identifies three different approaches to audience metrics: correspondents who are 1) data-driven; 2) data informed; and 3) data denialists. The article discusses the implications of these approaches for the media image of Africa that is distributed around the globe

About females and males: continuity and discontinuity in flies

Through the decades of relentless and dedicated studies in Drosophila melanogaster, the pathway that governs sexual development has been elucidated in great detail and has become a paradigm in understanding fundamental cell-fate decisions. However, recent phylogenetic studies show that the molecular strategy used in Drosophila deviates in some important aspects from those found in other dipteran flies and suggest that the Drosophila pathway is likely to be a derivative of a simpler and more common principle. In this essay, I will discuss the evolutionary plasticity of the sex-determining pathway based on studies in the common housefly, Musca domestica. Diversification appears to primarily arise from subtle differences in the regulation of the key switch gene transformer at the top of the pathway. On the basis of these findings I propose a new idea on how the Drosophila pathway may have evolved from a more archetypal system such as in M. domestica. In essence, the arrival of an X counting mechanism mediated by Sex-lethal to compensate for X linked gene dose differences set the stage for an intimate coupling of the two pathways. Its precedent recruitment to the dosage compensation pathway allowed for an intervention in the regulation of transformer where it gradually and eventually' completely substituted for a need of transformer autoregulation

Innovative multi‐scale approach to study the phenotypic variation of seedling leaves in four weedy Amaranthus species

Plant phenotyping on morpho‐anatomical traits through image analysis, from microscope images to large‐scale acquisitions through remote sensing, represents a low‐invasive tool providing insight into physiological and structural trait variation, as well as plant–environment interactions. High phenotype diversity in the genus Amaranthus includes annual weed species with high invasiveness and impact on important summer crops, and nutritive grain or vegetable crops. Identification of morpho‐anatomical leaf characters at very young stages across weedy amaranths could be useful for better understanding their performance in agroecosystems. We used an innovative multi‐scale approach with phenotype analyses of about 20 single‐leaf morphometric traits of four Amaranthus species through processing confocal microscopy and camera acquisitions. The results highlight that determination of leaf traits at different investigation levels highlight species‐specific traits at a juvenile stage, which are crucial for plant development, competition and establishment. Specifically, leaf circularity and hairiness Aspect Ratio better discriminated A. tuberculatus from other species. Also, leaf DW, hairiness area and perimeter variables allowed identification of dioecious amaranth species as distinct from monoecious species. The methodology used here provides a promising, reliable and low‐impact approach for the functional characterization of phylogenetically related species and for statistical quantification of traits involved in taxonomy and biodiversity studies

Evaluation of the BovineSNP50 genotyping array in four South African cattle populations

The BovineSNP50 genotyping array is a product with a wide range of applications in cattle such as genome-wide association studies, identification of copy number variation and investigation of genetic relationships among cattle breeds. It also holds potential for genomic selection, especially for traits that are expensive and difficult to measure. The successfulness of this chip for any of these applications depends on the degree of polymorphisms in the cattle breeds. The SNP50 array has not been validated in any South African cattle population and this could lead to overestimating the number of polymorphic SNPs available for application in it. This study is a first attempt to evaluate the Bovine64SNP50 genotyping array in the South African cattle population. Ninety six bovine samples, consisting of 45 Holstein, 29 Nguni, 12 Angus and 10 Nguni x Angus crossbred animals, were genotyped with the BovineSNP50 infinium assay. The results of this study demonstrated that 40 555 SNPs were polymorphic (MAF >0.05) in these breeds and indicate potential for application in South African cattle populations. Genomic information generated from the BovineSNP50 can now be applied in genetic prediction, genetic characterization and genome-wide association studies.The authors would like to thank the ARC-Biotechnology Platform for making their laboratory resources available for genotyping samples. Financial support from the ARC is greatly appreciated. Provision of semen on Holstein bulls by Taurus Co-operative is also acknowledged.http://www.sasas.co.za/am201

Genetic diversity and population structure in South African, French and Argentinian angora goats from genome-wide SNP data

The Angora goat populations in Argentina (AR), France (FR) and South Africa (SA) have been kept geographically and genetically distinct. Due to country-specific selection and breeding strategies, there is a need to characterize the populations on a genetic level. In this study we analysed genetic variability of Angora goats from three distinct geographical regions using the standardized 50k Goat SNP Chip. A total of 104 goats (AR: 30; FR: 26; SA: 48) were genotyped. Heterozygosity values as well as inbreeding coefficients across all autosomes per population were calculated. Diversity, as measured by expected heterozygosity (HE) ranged from 0.371 in the SA population to 0.397 in the AR population. The SA goats were the only population with a positive average inbreeding coefficient value of 0.009. After merging the three datasets, standard QC and LD-pruning, 15 105 SNPs remained for further analyses. Principal component and clustering analyses were used to visualize individual relationships within and between populations. All SA Angora goats were separated from the others and formed a well-defined, unique cluster, while outliers were identified in the FR and AR breeds. Apparent admixture between the AR and FR populations was observed, while both these populations showed signs of having some common ancestry with the SA goats. LD averaged over adjacent loci within the three populations per chromosome were calculated. The highest LD values estimated across populations were observed in the shorter intervals across populations. The Ne for the Angora breed was estimated to be 149 animals ten generations ago indicating a declining trend. Results confirmed that geographic isolation and different selection strategies caused genetic distinctiveness between the populations.S1 Fig. Admixture plots for K = 2–4 showing population structure of different Angora subpopulations.The authors thank Margarita Cano (supplying Argentinean Angora DNA samples), Hector Taddeo (for historical information on the Argentinian Angora breed) and Capgenes (supplying French Angora DNA samples and historical information on the French Angora breed).The Argentinian part (MP) of the project was financially supported by Instituto Nacional de Tecnologia Agropecuaria PNBIO1131033 project. The South African researchers acknowledge the National Research Foundation (grants KIC14011761093 (CV) and TP13073024535 (EVMK)) and the University of Pretoria Genomics Research Institute (CV) for financial support.http://www.plosone.orgam2016Animal and Wildlife Science