The Topology of Music Recommendation Networks

We study the topology of several music recommendation networks, which rise from relationships between artist, co-occurrence of songs in playlists or experts' recommendation. The analysis uncovers the emergence of complex network phenomena in this kind of recommendation networks, built considering artists as nodes and their resemblance as links. We observe structural properties that provide some hints on navigation and possible optimizations on the design of music recommendation systems. Finally, the analysis derived from existing music knowledge sources provides a deeper understanding of the human music similarity perceptions.Comment: 15 pages, 3 figure

The Social Network of Contemporary Popular Musicians

In this paper we analyze two social network datasets of contemporary musicians constructed from allmusic.com (AMG), a music and artists' information database: one is the collaboration network in which two musicians are connected if they have performed in or produced an album together, and the other is the similarity network in which they are connected if they where musically similar according to music experts. We find that, while both networks exhibit typical features of social networks such as high transitivity, several key network features, such as degree as well as betweenness distributions suggest fundamental differences in music collaborations and music similarity networks are created.Comment: 7 pages, 2 figure

Iron homeostasis in plants - a brief overview

Iron plays a crucial role in biochemistry and is an essential micronutrient for plants and humans alike. Although plentiful in the Earth's crust it is not usually found in a form readily accessible for plants to use. They must therefore sense and interact with their environment, and have evolved two different molecular strategies to take up iron in the root. Once inside, iron is complexed with chelators and distributed to sink tissues where it is used predominantly in the production of enzyme cofactors or components of electron transport chains. The processes of iron uptake, distribution and metabolism are overseen by tight regulatory mechanisms, at the transcriptional and post-transcriptional level, to avoid iron concentrations building to toxic excess. Iron is also loaded into seeds, where it is stored in vacuoles or in ferritin. This is important for human nutrition as seeds form the edible parts of many crop species. As such, increasing iron in seeds and other tissues is a major goal for biofortification efforts by both traditional breeding and biotechnological approaches

Sensor-Based Seeds for a Chaotic Stream Cipher

In this paper we have used a surface micromachined capacitive accelerometer in order to generate seeds that are suitable for secure communications between wireless smart sensors for IoT networks. These seeds have then been used in a chaotic stream cipher based on a Modified Logistic Map and a Linear Feedback Shift Register. The sequences generated by the chaotic stream cipher have been subjected to the randomness NIST tests. All the tests have been passed, proving that the proposed approach could be used for secure communications

Rotura espontánea del aparato extensor secundaria a artrosis de la articulación radiocubital distal

ResumenObjetivoPresentar los resultados funcionales de pacientes no reumáticos, intervenidos por roturas del aparato extensor con artrosis de la articulación radiocubital distal. Valorar la influencia de la varianza y la luxación dorsal del cúbito en estos pacientes.Material y métodoEstudio retrospectivo de los casos de rotura atraumática del aparato extensor a nivel de la articulación radio-cubital distal intervenidos en el periodo 2002-2012. Se recogen variables sociodemográficas, estudio radiológico centrado en análisis de factores desencadenantes: artropatía, morfología de la articulación, presencia de subluxación de la cabeza cubital y varianza cubital. Se descarta la enfermedad reumática mediante estudio analítico. Se detalla la técnica quirúrgica realizada según la presencia de factores desencadenantes y el número de tendones afectos. Se valora el resultado funcional por medio de la escala TAM, Quick-DASH y el dolor según la escala EVA.ResultadosSe identifican 8 casos de rotura espontánea del aparato extensor por artrosis en la articulación radio-cubital distal. Media de edad 73 años (66-81). Seguimiento medio 5 años (2-12). En 7 casos se observa afectación tendinosa múltiple, principalmente los encargados de los dedos medio, anular y meñique. En el estudio radiológico destaca la presencia de una varianza cubital minus en 3 casos. Resultado funcional según escala TAM: bueno en 5 casos y regular en 3 casos. EVA media de 2. Quick-DASH 21.7.ConclusionesLos pacientes presentan a medio-largo plazo un resultado funcional aceptable utilizando la escala TAM y el cuestionario Quick-DASH, con un dolor residual leve según la escala EVA. Todos los pacientes mantienen o mejoran su TAM comparados con su exploración preoperatoria, obteniendo un resultado bueno en el 62.5% de los casos. No es necesaria la presencia de una varianza plus o subluxación de la cabeza para desencadenar la rotura puesto que se observan 3 casos con varianza minus y sin subluxación.AbstractObjectiveTo present functional outcomes of surgery for ruptures of the extensor apparatus with osteoarthritis of the distal radio-ulnar joint in non rheumatic patients. To evaluate the influence of ulnar variance and dorsal dislocation of the ulna in these patients.Material and methodA retrospective study of atraumatic rupture of the extensor apparatus at the distal radio-ulnar joint in the period 2002-2012. Radiological study focused on analyzing trigger factors were performed. The surgical technique was performed taking into account number of affected tendons and joint disease. Functional outcome and pain is assessed by the TAM, Quick-DASH, VAS scale.Results8 cases of spontaneous rupture of extensor mechanism were identified due to osteoarthritis distal radio-ulnar joint. Mean age 73 years (66-81). Mean follow-up five years (2-12). In 7 cases multiple tendon involvement, mainly those responsible for the middle, ring and little fingers were seen. In the radiological study it was found the presence of an ulnar minus variance in 3 cases. Functional outcomes in the TAM scale were good in 5 cases and fair in 3 cases. EVA 2. Quick-DASH 21.7.ConclusionsAll patients reflect an acceptable functional outcome following TAM and Quick-DASH questionnaire, with a slight pain according to the visual analog scale. All patients maintained or improved their TAM scale compared with preoperative examination, obtaining a good result in 62.5% of cases. The presence of a variance plus or subluxation of the head to trigger the break is not required due to 3 patients with variance minus and without subluxation suffered tendon rupture

Self-synchronized Encryption for Physical Layer in 10Gbps Optical Links

In this work a new self-synchronized encryption method for 10 Gigabit optical links is proposed and developed. Necessary modifications to introduce this kind of encryption in physical layers based on 64b/66b encoding, such as 10GBase-R, have been considered. The proposed scheme encrypts directly the 64b/66b blocks by using a symmetric stream cipher based on an FPE (Format Preserving Encryption) block cipher operating in PSCFB (Pipelined Statistical Cipher Feedback) mode. One of the main novelties in this paper is the security analysis done for this mode. For the first time, an expression for the IND-CPA (Indistinguishability under Chosen-Plaintext Attack) advantage of any adversary over this scheme has been derived. Moreover, it has been concluded that this mode can be considered secure in the same way of traditional modes are. In addition, the overall system has been simulated and implemented in an FPGA (Field Programmable Gate Array). An encrypted optical link has been tested with Ethernet data frames, concluding that it is possible to cipher traffic at this level, getting maximum throughput and hiding traffic pattern from passive eavesdroppers

A New Approach to Analysis the Security of Compensated Measuring PUFs

In this paper we perform an entropy analysis and probability distribution analysis over simulated PUFs operating under a compensated measuring digitization scheme. The behavior of the PUFs have been simulated by generating a set of pseudorandom numbers uniformly distributed, which simulate the measured parameters, using the definition of the so called "topology of the PUF", i.e. the way in which different parameter measurements are compared to obtain a digital binary output. At this respect, we prove the existence of a shortcoming in the most commonly used PUF topologies. as well as provide some guidelines to overcome it

Chaotic Encryption Applied to Optical Ethernet in Industrial Control Systems

In the past decades, Ethernet has become an alternative technology for the field buses traditionally used in industrial control systems and distributed measurement systems. Among different transmission media in Ethernet standards, optical fiber provides the best bandwidth, excellent immunity to electromagnetic interference, and less signal loses than other wired media. Due to the absence of a standard that provides security at the physical layer of optical Ethernet links, the main motivation of this paper is to propose and implement the necessary modifications to introduce encryption in Ethernet 1000Base-X standard. This has consisted of symmetric streaming encryption of the 8b10b symbols flow at physical coding sublayer level, thanks to a keystream generator based on chaotic algorithm. The overall system has been implemented and tested in an field programmable gate array and Ethernet traffic has been encrypted and transmitted over an optical link. The experimental results show that it is possible to cipher traffic at this level and hide the complete Ethernet traffic pattern from passive eavesdroppers. In addition, no space overhead is introduced in data frames during encryption, achieving the maximum throughput

A new simple technique for improving the random properties of chaos-based cryptosystems

A new technique for improving the security of chaos-based stream ciphers has been proposed and tested experimentally. This technique manages to improve the randomness properties of the generated keystream by preventing the system to fall into short period cycles due to digitation. In order to test this technique, a stream cipher based on a Skew Tent Map algorithm has been implemented on a Virtex 7 FPGA. The randomness of the keystream generated by this system has been compared to the randomness of the keystream generated by the same system with the proposed randomness-enhancement technique. By subjecting both keystreams to the National Institute of Standards and Technology (NIST) tests, we have proved that our method can considerably improve the randomness of the generated keystreams. In order to incorporate our randomness-enhancement technique, only 41 extra slices have been needed, proving that, apart from effective, this method is also efficient in terms of area and hardware resources

Introduction to Physically Unclonable Fuctions: Properties and Applications

During the last years, Physically Unclonable Functions (PUFs) have become a very important research area in the field of hardware security due to their capability of generating volatile secret keys as well as providing a low-cost authentication. In this paper, an introduction to Physically Unclonable Functions is given, including their definition, properties and applications. Finally, as an example of how to design a PUF, the general structure of a ring oscillator PUF is presented