RC-NDN: Raptor Codes Enabled Named Data Networking

Information-centric networking (ICN) has been proposed to cope with the drawbacks of the Internet Protocol, namely scalability and security. The majority of research efforts in ICN have focused on routing and caching in wired networks, while little attention has been paid to optimizing the communication and caching efficiency in wireless networks. In this work, we study the application of Raptor codes to Named Data Networking (NDN), which is a popular ICN architecture, in order to minimize the number of transmitted messages and accelerate content retrieval times. We propose RC-NDN, which is a NDN compatible Raptor codes architecture. In contrast to other coding-based NDN solutions that employ network codes, RC-NDN considers security architectures inherent to NDN. Moreover, different from existing network coding based solutions for NDN, RC-NDN does not require significant computational resources, which renders it appropriate for low cost networks. We evaluate RC-NDN in mobile scenarios with high mobility. Evaluations show that RC-NDN outperforms the original NDN significantly. RC-NDN is particularly efficient in dense environments, where retrieval times can be reduced by 83% and the number of Data transmissions by 84.5% compared to NDN.

Labour Migration, Trade and Investment: From Fragmentation to Coherence

Trade, investment and migration are strongly intertwined, being three key factors in international production. Yet, law and regulation of the three has remained highly fragmented. Trade is regulated by the WTO on the multilateral level, and through preferential trade agreements on the regional and bilateral levels – it is fragmented and complex in its own right. Investment, on the other hand, is mainly regulated through bilateral investment treaties with no strong links to the regulation of trade or migration. And, finally, migration is regulated by a web of different international, regional and bilateral agreements which focus on a variety of different aspects of migration ranging from humanitarian to economic. The problems of institutional fragmentation in international law are well known. There is no organizational forum for coherent strategy-making on the multilateral level covering all three areas. Normative regulations may thus contradict each other. Trade regulation may bring about liberalization of access for service providers, but eventually faces problems in recruiting the best people from abroad. Investors may withdraw investment without being held liable for disruptions to labour and to the livelihood and infrastructure of towns and communities affected by disinvestment. Finally, migration policies do not seem to have a significant impact as long as trade policies and investment policies are not working in a way that is conducive to reducing migration pressure, as trade and investment are simply more powerful on the regulatory level than migration. This chapter addresses the question as to how fragmentation of the three fields could be reme-died and greater coherence between these three areas of factor allocation in international economic relations and law could be achieved. It shows that migration regulation on the international level is lagging behind that on trade and investment. Stronger coordination and consideration of migration in trade and investment policy, and stronger international cooperation in migration, will provide the foundations for a coherent international architecture in the field.

Contribution of APOBEC3G/F Activity to the Development of Low-Abundance Drug-Resistant HIV-1 variants.

Plasma drug-resistant minority HIV-1 variants (DRMV) increase the risk of virological failure to first-line NNRTI antiretroviral therapy (ART). The origin of DRMVs in ART-naive patients, however, remains unclear. In a large pan-European case-control study investigating the clinical relevance of pre-existing DRMVs using 454 pyrosequencing, the six most prevalent plasma DRMVs detected corresponded to G-to-A nucleotide mutations (V90I, V106I, V108I, E138K, M184I and M230I). Here, we evaluated if such DRMVs could have emerged from APOBEC3G/F activity. Out of 236 ART-naïve evaluated subjects, APOBEC3G/F hypermutation signatures were detected in plasma viruses of 14 (5.9%) individuals. Samples with minority E138K, M184I, and M230I mutations, but not those with V90I, V106I, or V108I were significantly associated with APOBEC3G/F activity (Fisher's p<0.005), defined as presence of >0.5% of sample sequences with an APOBEC3G/F signature. Mutations E138K, M184I and M230I co-occurred in the same sequence as APOBEC3G/F signatures in 3/9 (33%), 5/11 (45%) and 4/8 (50%) of samples, respectively; such linkage was not found for V90I, V106I or V108I. In-frame STOP codons were observed in 1.5% of all clonal sequences; 14.8% of them co-occurred with APOBEC3G/F signatures. APOBEC3G/F-associated E138K, M184I and M230I appeared within clonal sequences containing in-frame STOP codons in 2/3 (66%), 5/5 (100%) and 4/4 (100%) of the samples. In a reanalysis of the parent case-control study, presence of APOBEC3G/F signatures was not associated with virological failure. In conclusion, the contribution of APOBEC3G/F editing to the development of DRMVs is very limited and does not affect the efficacy of NNRTI ART.

Twenty years' experience with the Swiss data registry for assisted reproductive medicine: outcomes, key trends and recommendations for improved practice.

QUESTIONS UNDER STUDY The impact of assisted reproductive technology (ART) on Swiss demography was quantified. From 1993 to 2012 the number of deliveries, including multiples, generated by ART was compared with overall delivery numbers. Swiss experts in ART collaborated in a consensus to increase successful outcomes, to reduce the incidence of complications of ART and to validate recommendations through statistical review of available data. METHODS Data generated between 1993 and 2012 and published by the Federal Office of Statistics (BfS) were compared with the Swiss database on ART (FIVNAT-CH) as organised by the Swiss Society of Reproductive Medicine (SGRM). From these analyses a panel of Swiss experts in ART extracted recommendations to improve current practice, to prevent complications related to ART and to recommend changes in current Swiss legislation dealing with ART. RESULTS Since 1993 the age of women giving birth rose together with the number of women asking for ART. This demographic trend was reflected in a rise in the number of deliveries generated by ART (in 2012: 2.2%) and the proportion of multiple births (in 2012: 17.6%). The outcome of ART was most negatively influenced by the age of the treated patient. The number of retrieved oocytes decisively impacted the likelihood of delivery, the risk of multiple births and the incidence of ovarian hyperstimulation syndrome. CONCLUSIONS Optimal ovarian stimulation should be designed for the retrieval of 10 to 15 oocytes per treatment. Swiss legislation should enable and stimulate a policy of elective single embryo transfer to avoid multiple births.

Time-dependent supraimplant mucosa changes: short communication

PURPOSE The aim of this short communication was to analyze time-dependent changes of the supraimplant mucosa architecture in the esthetic zone. MATERIALS AND METHODS Five patients underwent single-tooth replacement with implant crowns in the anterior maxilla. The supraimplant soft tissue was conditioned with fixed provisional crowns. Quadrantlike digital impressions were taken with an intraoral optical scanning device at three time points: t0, immediately after removal of the provisional (baseline); t1, after 5 minutes; and t2, after 10 minutes. To analyze time-dependent mucosal changes, the corresponding digital files were superimposed for each patient, and baseline (t0) scans were compared with t1 and t2 scans, respectively. Wilcoxon rank sum tests were used for statistical calculations with a strict level of significance at P < .01. RESULTS Mean values for supraimplant soft tissue changes were statistically significantly different after 5 minutes (5.5%; standard deviation ± 0.3%) in comparison to the results after 10 minutes (21.7%; standard deviation ± 1.8%). The direction of mucosa shrinkage showed a trend toward palatal sites. CONCLUSION Based on the findings of this analysis, changes in supraimplant mucosa architecture seem to be affected only slightly during the first 5 minutes after removal of soft tissue support.

NOVEL PHANTOMS AND POST-PROCESSING FOR DIFFUSION SPECTRUM IMAGING

High Angular Resolution Diffusion Imaging (HARDI) techniques, including Diffusion Spectrum Imaging (DSI), have been proposed to resolve crossing and other complex fiber architecture in the human brain white matter. In these methods, directional information of diffusion is inferred from the peaks in the orientation distribution function (ODF). Extensive studies using histology on macaque brain, cat cerebellum, rat hippocampus and optic tracts, and bovine tongue are qualitatively in agreement with the DSI-derived ODFs and tractography. However, there are only two studies in the literature which validated the DSI results using physical phantoms and both these studies were not performed on a clinical MRI scanner. Also, the limited studies which optimized DSI in a clinical setting, did not involve a comparison against physical phantoms. Finally, there is lack of consensus on the necessary pre- and post-processing steps in DSI; and ground truth diffusion fiber phantoms are not yet standardized. Therefore, the aims of this dissertation were to design and construct novel diffusion phantoms, employ post-processing techniques in order to systematically validate and optimize (DSI)-derived fiber ODFs in the crossing regions on a clinical 3T MR scanner, and develop user-friendly software for DSI data reconstruction and analysis. Phantoms with a fixed crossing fiber configuration of two crossing fibers at 90° and 45° respectively along with a phantom with three crossing fibers at 60°, using novel hollow plastic capillaries and novel placeholders, were constructed. T2-weighted MRI results on these phantoms demonstrated high SNR, homogeneous signal, and absence of air bubbles. Also, a technique to deconvolve the response function of an individual peak from the overall ODF was implemented, in addition to other DSI post-processing steps. This technique greatly improved the angular resolution of the otherwise unresolvable peaks in a crossing fiber ODF. The effects of DSI acquisition parameters and SNR on the resultant angular accuracy of DSI on the clinical scanner were studied and quantified using the developed phantoms. With a high angular direction sampling and reasonable levels of SNR, quantification of a crossing region in the 90°, 45° and 60° phantoms resulted in a successful detection of angular information with mean ± SD of 86.93°±2.65°, 44.61°±1.6° and 60.03°±2.21° respectively, while simultaneously enhancing the ODFs in regions containing single fibers. For the applicability of these validated methodologies in DSI, improvement in ODFs and fiber tracking from known crossing fiber regions in normal human subjects were demonstrated; and an in-house software package in MATLAB which streamlines the data reconstruction and post-processing for DSI, with easy to use graphical user interface was developed. In conclusion, the phantoms developed in this dissertation offer a means of providing ground truth for validation of reconstruction and tractography algorithms of various diffusion models (including DSI). Also, the deconvolution methodology (when applied as an additional DSI post-processing step) significantly improved the angular accuracy of the ODFs obtained from DSI, and should be applicable to ODFs obtained from the other high angular resolution diffusion imaging techniques.

Investigación en el campo del arte : Presentación de un caso y niveles de anclaje

Muchas veces en la investigación en el campo del arte los términos son ambiguos si no se los precisa. Retomamos la distinción entre cuestiones ontológicas (tipos de objetos de investigación), epistemológicas (conocimientos producidos) y metodológicas propiamente dichas (discusiones en torno de los vínculos con las Ciencias Sociales). A su vez distinguimos la investigación en el campo del arte de la investigación artística (IENA) propiamente dicha, reservando para esta última los sentidos de un tipo de indagación estética creativa en la incorporación de nuevos lenguajes y modalidades de obras. El trabajo busca ser una excusa para que, presentando una exploración en curso dentro de la casa/museo El fogón de los arrieros, podamos actualizar brevemente un debate sobre dos concepciones vinculadas: la IENA y la investigación sobre objetos artísticos. Además de arriesgar una propuesta de abordaje con matriz de datos para estratificar los niveles de análisis, dejando interrogantes para sucesivos planteos que contengan los rasgos propios de la pesquisa teórica y práctica sobre artes.

Belleza y Felicidad en la vorágine del 2001 : Algunas percepciones contemporáneas sobre las condiciones de un arte político

Muy discutida en su momento, la producción de Belleza y Felicidad, y especialmente los debates que generó en torno suyo, permite iluminar retrospectivamente los conceptos y valoraciones subyacentes en las discusiones sobre arte y poesía de fines de los noventa y principios de la década del dos mil. Este artículo recorre, desde esta premisa, tres textos críticos publicados en el período por Martín Prieto y Daniel García Helder, César Aira y Mario Ortiz, en los que a propósito de la lectura crítica de Belleza y Felicidad, se ordenan ciertos modos posibles de la vinculación entre poesía y política.

La representación contemporánea del cuerpo desnudo : El objeto sexual en el cambio de siglo XX al XXI

Los cambios que el pensamiento feminista ha producido en nuestra personalidad como sociedad, en nuestra manera de conducirnos y expresarnos, invitan a trabajar sobre ellos en profundidad. En estas líneas se analizan algunos trabajos de artistas feministas y 'post-feministas', relacionándolos con la tradición de representación del cuerpo humano en la historia del arte. La denominación objeto sexual no es un calificativo que se aplique hoy únicamente al sexo femenino. Imágenes femeninas y masculinas son utilizadas por la sociedad de consumo para vender sus productos como reclamo. Las particulares formas de entender y presentar el cuerpo humano como desperdicio, consumible o despojo, no son tampoco patrimonio de un solo sexo. Desde la perspectiva de la representación del cuerpo humano se deben analizar las nuevas estrategias nacidas a partir del compromiso de respeto hacia los derechos sociales de las mujeres

'Lo español' en la arquitectura de las primeras décadas del siglo XX : Miradas e imágenes a ambas orillas del Atlántico

En el marco de un ya concluido proyecto de investigación titulado: 'Imágenes de España en la arquitectura rioplatense' analizamos las impresiones del célebre arquitecto argentino Martín Noel en su libro de viajes España vista otra vez, escrito y publicado en la Península mientras dirigía en Sevilla las obras del Pabellón Argentino en la Exposición Iberoamericana de 1929. Estábamos por abocarnos a otros temas, cuando encontramos casualmente un raro libro español de la época prologado por Noel. Nos referimos al volumen Casas de campo españolas, de Alfredo Baeschlin, arquitecto suizo residente en España. El libro reúne cincuenta proyectos originales de viviendas 'típicas' de las diversas regiones de España con profusión de planos, perspectivas y una memoria escrita en la que se destacan tanto sus virtudes funcionales como su respeto al carácter 'español'. Pensamos pues que dicho azaroso hallazgo constituye una oportunidad para analizar qué se entendía por 'lo español' en la arquitectura de los años veinte, a ambas orillas del Atlántico, estudiando las miradas cruzadas del autor europeo y el prologuista americano con la particularidad de que, pese a ser ambos entusiastas estudiosos de lo hispano, ninguno de ellos era español

Investigación en el campo del arte : Presentación de un caso y niveles de anclaje

Muchas veces en la investigación en el campo del arte los términos son ambiguos si no se los precisa. Retomamos la distinción entre cuestiones ontológicas (tipos de objetos de investigación), epistemológicas (conocimientos producidos) y metodológicas propiamente dichas (discusiones en torno de los vínculos con las Ciencias Sociales). A su vez distinguimos la investigación en el campo del arte de la investigación artística (IENA) propiamente dicha, reservando para esta última los sentidos de un tipo de indagación estética creativa en la incorporación de nuevos lenguajes y modalidades de obras. El trabajo busca ser una excusa para que, presentando una exploración en curso dentro de la casa/museo El fogón de los arrieros, podamos actualizar brevemente un debate sobre dos concepciones vinculadas: la IENA y la investigación sobre objetos artísticos. Además de arriesgar una propuesta de abordaje con matriz de datos para estratificar los niveles de análisis, dejando interrogantes para sucesivos planteos que contengan los rasgos propios de la pesquisa teórica y práctica sobre artes.

Investigación en el campo del arte : Presentación de un caso y niveles de anclaje

Muchas veces en la investigación en el campo del arte los términos son ambiguos si no se los precisa. Retomamos la distinción entre cuestiones ontológicas (tipos de objetos de investigación), epistemológicas (conocimientos producidos) y metodológicas propiamente dichas (discusiones en torno de los vínculos con las Ciencias Sociales). A su vez distinguimos la investigación en el campo del arte de la investigación artística (IENA) propiamente dicha, reservando para esta última los sentidos de un tipo de indagación estética creativa en la incorporación de nuevos lenguajes y modalidades de obras. El trabajo busca ser una excusa para que, presentando una exploración en curso dentro de la casa/museo El fogón de los arrieros, podamos actualizar brevemente un debate sobre dos concepciones vinculadas: la IENA y la investigación sobre objetos artísticos. Además de arriesgar una propuesta de abordaje con matriz de datos para estratificar los niveles de análisis, dejando interrogantes para sucesivos planteos que contengan los rasgos propios de la pesquisa teórica y práctica sobre artes.

Belleza y Felicidad en la vorágine del 2001 : Algunas percepciones contemporáneas sobre las condiciones de un arte político

Muy discutida en su momento, la producción de Belleza y Felicidad, y especialmente los debates que generó en torno suyo, permite iluminar retrospectivamente los conceptos y valoraciones subyacentes en las discusiones sobre arte y poesía de fines de los noventa y principios de la década del dos mil. Este artículo recorre, desde esta premisa, tres textos críticos publicados en el período por Martín Prieto y Daniel García Helder, César Aira y Mario Ortiz, en los que a propósito de la lectura crítica de Belleza y Felicidad, se ordenan ciertos modos posibles de la vinculación entre poesía y política.