A Vocabulary for Growth: Topic Modeling of Content Popularity Evolution

In this paper, we present a novel method to predict the long-term popularity of user-generated content (UGC). At first, the method clusters the dynamics of UGC popularity into a vocabulary of growth in popularity (sequence) by using a mixture model. Eventually, the method assigns to each sequence a topic model to describe the dynamics of the sequence in a compact way. We then use this topic model to identify similar patterns of growth in popularity of newly observed UGC. The proposed method has two key features: First, it considers the historical dynamics of the UGC popularity, and second it provides long-term popularity prediction. Results on the real dataset of UGC show that the proposed method is flexible, and able to accurately forecast the complete growth in popularity of a given UGC

The impact of particle radiotherapy on the functioning of cardiac implantable electronic devices: a systematic review of in vitro and in vivo studies according to PICO criteria

The number of oncological patients who may benefit from proton beam radiotherapy (PBT) or carbon ion radiotherapy (CIRT), overall referred to as particle radiotherapy (RT), is expected to strongly increase in the next future, as well as the number of cardiological patients requiring cardiac implantable electronic devices (CIEDs). The management of patients with a CIED requiring particle RT deserves peculiar attention compared to those undergoing conventional photon beam RT, mostly due to the potential generation of secondary neutrons by particle beams interactions. Current consensus documents recommend managing these patients as being at intermediate/high risk of RT-induced device malfunctioning regardless of the dose on the CIED and the beam delivery method used, despite the last one significantly affects secondary neutrons generation (very limited neutrons production with active scanning as opposed to the passive scattering technique). The key issues for the current review were expressed in four questions according to the Population, Intervention, Control, Outcome criteria. Three in vitro and five in vivo studies were included. Based on the available data, PBT and CIRT with active scanning have a limited potential to interfere with CIED that has only emerged from in vitro study so far, while a significant potential for neutron-related, not severe, CIED malfunctions (resets) was consistently reported in both clinical and in vitro studies with passive scattering

Pantethine treatment is effective in recovering the disease phenotype induced by ketogenic diet in a pantothenate kinase-associated neurodegeneration mouse model

Pantothenate kinase-associated neurodegeneration, caused by mutations in the PANK2 gene, is an autosomal recessive disorder characterized by dystonia, dysarthria, rigidity, pigmentary retinal degeneration and brain iron accumulation. PANK2 encodes the mitochondrial enzyme pantothenate kinase type 2, responsible for the phosphorylation of pantothenate or vitamin B5 in the biosynthesis of co-enzyme A. A Pank2 knockout (Pank2(−/−)) mouse model did not recapitulate the human disease but showed azoospermia and mitochondrial dysfunctions. We challenged this mouse model with a low glucose and high lipid content diet (ketogenic diet) to stimulate lipid use by mitochondrial beta-oxidation. In the presence of a shortage of co-enzyme A, this diet could evoke a general impairment of bioenergetic metabolism. Only Pank2(−/−) mice fed with a ketogenic diet developed a pantothenate kinase-associated neurodegeneration-like syndrome characterized by severe motor dysfunction, neurodegeneration and severely altered mitochondria in the central and peripheral nervous systems. These mice also showed structural alteration of muscle morphology, which was comparable with that observed in a patient with pantothenate kinase-associated neurodegeneration. We here demonstrate that pantethine administration can prevent the onset of the neuromuscular phenotype in mice suggesting the possibility of experimental treatment in patients with pantothenate kinase-associated neurodegeneration

Antidepressant and antipsychotic use in an Italian pediatric population

<p>Abstract</p> <p>Background</p> <p>The safety and effectiveness of psychotropic drug use in the paediatric population is widely debated, in particular because of the lack of data concerning long term effects.</p> <p>In Italy the prevalence of psychotropic drug prescriptions increased in the early 2000s and decreased afterwards. In such a context, a study with the aim to estimate the incidence and prevalence of psychotropic drug prescription in the paediatric population and to describe diagnostic and therapeutic approaches was performed.</p> <p>Methods</p> <p>The study population was composed of 76,000 youths less than 18 years and living in the area covered by the local health unit of Verona, Italy. The data source was the Verona local health unit's administrative prescription database. Prevalence and incidence of antidepressant and/or antipsychotic drug prescriptions in the 2004-2008 period were estimated. Children and adolescents receiving antidepressant and/or antipsychotic drug prescriptions between 1 January 2005 and 31 December 2006 were identified and questionnaires were sent to the prescribers with the aim to collect data concerning diagnostic and therapeutic approaches, and care strategies.</p> <p>Results</p> <p>The prevalence of psychotropic drug prescriptions did not change in the 2004-2008 period, while incidence slightly increased (from 7.0 in 2005 to 8.3 per 10,000 in 2008). Between 1 January 2005 and 31 December 2006, 111 youths received at least one psychotropic drug prescription, 91 of whom received antidepressants. Only 28 patients attended child and adolescent psychiatry services. Information concerning diagnostic and therapeutic approaches, and care strategies was collected for 52 patients (47%). Anxiety-depressive syndrome and attention disorders were the diseases for which psychotropic drugs were most commonly prescribed. In all, 75% youths also received psychological support and 20% were prescribed drugs for 2 or more years.</p> <p>Conclusions</p> <p>Despite the low drug prescription prevalence, the finding that most children were not cared for by child and adolescent psychiatric services is of concern and calls for a systematic, continuous monitoring of psychopharmacological treatments.</p

Estimating Routing Symmetry on Single Links by Passive Flow Measurements

The assumption of routing symmetry is often embedded into traffic analysis and classification tools. This paper uses passively captured network data to estimate the amount of traffic actually routed symmetrically on a specic link. We propose a Flow-Based Symmetry Estimator (FSE) a set of metrics to assess symmetry in terms of flows, packets and bytes, which disregards inherently asymmetrical traffic such as UDP, ICMP and TCP background radiation. This normalized metric allows fair comparison of symmetry across different links. We evaluate our method on a large heterogeneous dataset, and confirm anecdotal reports that routing symmetry typically does not hold for non-edge Internet links, and decreases as one moves toward core backbone links, due to routing policy complexity. Our proposed metric for traffic asymmetry induced by routing policies will help the community improve traffic characterization techniques and formats, but also support quantitative formalization of routing policy effects on links in the wild

Estimating Routing Symmetry on Single Links by Passive Flow Measurements

The assumption of routing symmetry is often embedded into traffic analysis and classification tools. This paper uses passively captured network data to estimate the amount of traffic actually routed symmetrically on a specic link. We propose a Flow-Based Symmetry Estimator (FSE) a set of metrics to assess symmetry in terms of flows, packets and bytes, which disregards inherently asymmetrical traffic such as UDP, ICMP and TCP background radiation. This normalized metric allows fair comparison of symmetry across different links. We evaluate our method on a large heterogeneous dataset, and confirm anecdotal reports that routing symmetry typically does not hold for non-edge Internet links, and decreases as one moves toward core backbone links, due to routing policy complexity. Our proposed metric for traffic asymmetry induced by routing policies will help the community improve traffic characterization techniques and formats, but also support quantitative formalization of routing policy effects on links in the wild

Detecting HTTP Tunnels with Statistical Mechanisms

Abstract — Application Level Gateways and firewalls are commonly used to enforce security policies at network boundaries, especially in large-sized business networks. However, several mechanisms can be used to circumvent these policies and bypass the whole security infrastructure: for example, tunneling an (otherwise blocked) application layer protocol into another one allowed by the policy, such as HTTP. In this paper we propose the application of a statistically-based traffic classification technique to solve this problem. By the analysis of inter–arrival time, size and order of the packets crossing a gateway, we show that it is possible to detect with high accuracy whether an observed flow is carrying a legitimate HTTP session, or the flow is being used to tunnel another protocol. This paper describes how this technique can be used effectively to enhance Application Level Gateways and firewalls, helping to better apply network security policies. I

Traffic Classification through Simple Statistical Fingerprinting

The classification of IP flows according to the application that generated them is at the basis of any modern network management platform. However, classical techniques such as the ones based on the analysis of transport layer or application layer information are rapidly becoming ineffective. In this paper we present a flow classification mechanism based on three simple properties of the captured IP packets: their size, inter-arrival time and arrival order. Even though these quantities have already been used in the past to define classification techniques, our contribution is based on new structures called protocol fingerprints, which express such quantities in a compact and efficient way, and on a simple classification algorithm based on normalized thresholds. Although at a very early stage of development, the proposed technique is showing promising preliminary results from the classification of a reduced set of protocols

Analysis of UDP Traffic Usage on Internet Backbone Links

It is still an accepted assumption that Internet traffic is dominated by TCP. However, the rise of new streaming applications (e.g. IPTV such as PPStream, PPLive) and new P2P protocols (e.g. uTP) trying to avoid traffic shaping techniques (such as RST packet injection) are expected to increase the usage of UDP as transport protocol. Since UDP lacks congestion-control, this could potentially raise serious concerns about fairness and stability in the Internet. The goal of this paper is to shed some lights on the assumption that TCP is the dominant transport protocol on the Internet. We evaluate the amount of UDP and TCP traffic, in terms of flows, packets and bytes, on traces collected in the period 2002-2009 on several backbone links located in the US and Sweden. According to our best available data,the use of UDP as transport protocol is gaining popularity in the recent years, especially in terms of flow numbers. A first analysis suggests that most UDP flows use random high ports and carry few packets and little data. This indicates that the recent increases in UDP traffic are a side product of the general increase of P2P traffic, using random ports in order to evade detection and utilizing UDP as signaling traffic for establishing P2P overlay networks