Inside Dropbox: Understanding Personal Cloud Storage Services

Personal cloud storage services are gaining popularity. With a rush of providers to enter the market and an increasing of- fer of cheap storage space, it is to be expected that cloud storage will soon generate a high amount of Internet traffic. Very little is known about the architecture and the perfor- mance of such systems, and the workload they have to face. This understanding is essential for designing efficient cloud storage systems and predicting their impact on the network. This paper presents a characterization of Dropbox, the leading solution in personal cloud storage in our datasets. By means of passive measurements, we analyze data from four vantage points in Europe, collected during 42 consecu- tive days. Our contributions are threefold: Firstly, we are the first to study Dropbox, which we show to be the most widely-used cloud storage system, already accounting for a volume equivalent to around one third of the YouTube traffic at campus networks on some days. Secondly, we characterize the workload typical users in different environments gener- ate to the system, highlighting how this reflects on network traffic. Lastly, our results show possible performance bot- tlenecks caused by both the current system architecture and the storage protocol. This is exacerbated for users connected far from control and storage data-center

On the Adoption of the Elliptic Curve Digital Signature Algorithm (ECDSA) in DNSSEC

The Domain Name System Security Extensions (DNSSEC) are steadily being deployed across the Internet. DNSSEC extends the DNS protocol with two vital security properties, authenticity and integrity, using digital signatures. While DNSSEC is meant to solve security issues in the DNS, it also introduces a new one: the digital signatures significantly increase DNS packet sizes, making DNSSEC an attractive vector to abuse in amplification denial-of-service attacks. By default, DNSSEC uses RSA for digital signatures. Earlier work has shown that alternative signature schemes, based on elliptic curve cryptography, can significantly reduce the impact of signatures on DNS response sizes. In this paper we study the actual adoption of ECDSA by DNSSEC operators, based on longitudinal datasets covering over 50% of the global DNS namespace over a period of 1.5 years. Adoption is still marginal, with just 2.3% of DNSSEC-signed domains in the .com TLD using ECDSA. Nevertheless, use of ECDSA is growing, with at least one large operator leading the pack. And adoption could be up to 42% higher. As we demonstrate, there are barriers to deployment that hamper adoption. Operators wishing to deploy DNSSEC using current recommendations (with ECDSA as signing algorithm) must be mindful of this when planning their deployment

The Internet of Names: A DNS Big Dataset - Actively Measuring 50% of the Entire DNS Name Space, Every Day

The Domain Name System (DNS) is part of the core infrastructure of the Internet. Tracking changes in the DNS over time provides valuable information about the evolution of the Internet’s infrastructure. Until now, only one large-scale approach to perform these kinds of measurements existed, passive DNS (pDNS). While pDNS is useful for applications like tracing security incidents, it does not provide sufficient information to reliably track DNS changes over time. We use a complementary approach based on active measurements, which provides a unique, comprehensive dataset on the evolution of DNS over time. Our high-performance infrastructure performs Internet-scale active measurements, currently querying over 50% of the DNS name space on a daily basis. Our infrastructure is designed from the ground up to enable big data analysis approaches on, e.g., a Hadoop cluster. With this novel approach we aim for a quantum leap in DNS-based measurement and analysis of the Internet

Consistency of maternal cognitions and principles across the first five months following preterm and term deliveries.

The aims of this study were to examine and compare the development of parenting cognitions and principles in mothers following preterm and term deliveries. Parenting cognitions about child development, including thinking that is restricted to single causes and single outcomes (categorical thinking) and thinking that takes into account multiple perspectives (perspectivist thinking), have been shown to relate to child outcomes. Parenting principles about using routines (structure) or infant cues (attunement) to guide daily caregiving have been shown to relate to caregiving practices. We investigated the continuity and stability of parenting cognitions and principles in the days following birth to 5 months postpartum for mothers of infants born term and preterm. All parenting cognitions were stable across time. Categorical thinking increased at a group level across time in mothers of preterm, but not term, infants. Perspectivist thinking increased at a group level for first-time mothers (regardless of birth status) and tended to be lower in mothers of preterm infants. Structure at birth did not predict later structure (and so was unstable) in mothers of preterm, but not term, infants and neither group changed in mean level across time. Attunement was consistent across time in both groups of mothers. These results indicate that prematurity has multiple, diverse effects on parenting beliefs, which may in turn influence maternal behavior and child outcomes.Alice Winstanley was supported by a National Institutes of Health–Wellcome Trust four-year PhD studentship (084911/Z/08/Z), and Rebecca Sperotto was supported by a PhD studentship from the Waterloo Foundation and School of Psychology, Cardiff University. Diane L. Putnick and Marc H. Bornstein were supported by the intramural program of the NIH, NICHD.This is the final published version. It was originally published by Elsevier at http://www.sciencedirect.com/science/article/pii/S0163638314000939#

Mesoscopic Simulations of Biological Membranes

Se realiza una revisión bibliográfica sobre el plan de comunicación en un contexto en el que los medios propios coexisten con los pagados y ganados y una propuesta de plan de comunicación integrada.Faz-se uma revisão bibliográfica sobre o plano de comunicação em um contexto no qual os meios próprios coexistem com os pagos e vencidos e uma proposta de plano de comunicação integrado.A bibliographic review is made about communications plan in a context in which the own means coexist with paid and won ones. A proposal of integrated communication plan is discussed