Adaptive filtering of MPEG system streams in IP networks

Congestion and large differences in available link bandwidth create challenges for the design of applications that want to deliver high quality video over the Internet. We present an efficient adaptive filter for MPEG System streams that can be placed in the network (e.g., as an active service). This filter adjusts the bandwidth demands of an MPEG System stream to the available bandwidth without transcoding while maintaining synchronization between the streams embedded in the MPEG System. The filter is network-friendly: it is fair with respect to other (TCP) competing streams and it avoids generating bursty traffic. This paper presents the system architecture and an evaluation of our implementation in three different operating environments: a networking testbed in a laboratory environment, a home-user scenario (DSL line with 640Kbit/s), and a wide area network covering the Atlantic (server in Europe, client in the US). Moreover we examine the network-friendliness of the adaptation protocol and the relationship between the quality of the received continuous media and the protocol's aggressiveness. Our architecture is based on efficient MPEG System filtering to achieve high-quality video over best-effort network

SketchLib: enabling efficient sketch-based monitoring on programmable switches

CNS-2107086 - National Science Foundation; CNS-2106946 - National Science FoundationPublished versio

Can User-Level Probing Detect and Diagnose Common Home-WLAN Pathologies?

Common WLAN pathologies include low signal-to-noise ratio, congestion, hidden terminals or interference from non-802.11 devices and phenomena. Prior work has focused on the detection and diagnosis of such problems using layer-2 information from 802.11 devices and special-purpose access points and monitors, which may not be generally available. Here, we investigate a userlevel approach: is it possible to detect and diagnose 802.11 pathologies with strictly user-level active probing, without any cooperation from, and without any visibility in, layer-2 devices? In this paper, we present preliminary but promising results indicating that such diagnostics are feasible

A scalable Peer-to-Peer System for Music Content and Information Retrieval

Currently a large percentage of internet traffice consists of music files, typically stored in MP3 compressed audio format, shared and exchanged over Peer-to-Peer (P2P) networks. Searching for music is performed by specifying keywords and naive string matching techniques. In the past years the emerging research area of Music Information Retrieval (MIR) has produced a variety of new ways of looking at the problem of music search. Such MIR techniques can significantly enhance the ways users search for music over P2P networks. In order for that to happen there are two main challenges that need to be addressed: 1) scalability to large collections and number of peers 2) richer set of search semantics that can support MIR especially when retrieval is content-based. In this paper, we describe a scalable P2P system that uses Rendezvouz Points (RPs) for music metadata registration and query resolution, that supports atribute-value search semantics as well as content-based retrieval. The performance of the system has been evaluated in large scale usage scenarios using "real" automatically calculated musical content descriptors

An ambispective cohort study on treatment outcomes of patients with epilepsy in a tertiary epilepsy center in Rwanda and recommendations for improved epilepsy care

\u3cp\u3eObjective: Because outcome data inform and drive healthcare decisions and improvement of patient care, this study aimed to gain a deep understanding of sociodemographic profiles and treatment outcomes of newly presenting and recently diagnosed persons living with epilepsy (PwE) at a tertiary epilepsy center in Rwanda. Methods: In June 2016 (T1), as a first stage of this single-center cohort study, an ambispective chart review was conducted on baseline sociodemographic and disease characteristics of PwE using a structured questionnaire. Missing data were obtained by phone interview. In 2017, follow-up data were collected by phone interview on treatment outcomes after 15-months (T2). Results: Of 406 PwE screened, 235 were included at T1 and outcomes on 166 PwE were obtained at T2. More than 70% were <20 years of age, with a male preponderance. A high number of patients were aged ≥20 years, were single (67.4%), unemployed (41.5%), and had no formal education or primary level education (53.9%), possibly reflecting stigma. A mean delay in diagnosis since first seizure increased with age at first seizure, amounting to 3 years for patients aged ≥20 years. At T2, 69.6% of 166 patients who could be contacted reported no seizures in the previous month. Valproate monotherapy was the most frequently prescribed treatment. At T2, 47% had discontinued treatment, which was often not recommended by a physician, despite medical insurance coverage in >90% of patients. Only 19% reported an adverse event. Marked and partial improvement in quality of life (QoL) was reported by, respectively, 50.9% and 32.7% of patients. Significance: Encouraging results on improved seizure control and QoL were observed at follow-up. The treatment gap remains high due to loss to follow-up and treatment discontinuation. In this article, we discuss needs and recommendations for improving patient care, requiring concerted efforts of stakeholders at all levels of the healthcare system.\u3c/p\u3

Placental growth factor inhibition modulates the interplay between hypoxia and unfolded protein response in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality. We previously showed that the inhibition of placental growth factor (PlGF) exerts antitumour effects and induces vessel normalisation, possibly reducing hypoxia. However, the exact mechanism underlying these effects remains unclear. Because hypoxia and endoplasmic reticulum stress, which activates the unfolded protein response (UPR), have been implicated in HCC progression, we assessed the interactions between PlGF and these microenvironmental stresses. Methods: PlGF knockout mice and validated monoclonal anti-PlGF antibodies were used in a diethylnitrosamine-induced mouse model for HCC. We examined the interactions among hypoxia, UPR activation and PlGF induction in HCC cells. Results: Both the genetic and pharmacological inhibitions of PlGF reduced the chaperone levels and the activation of the PKR-like endoplasmic reticulum kinase (PERK) pathway of the UPR in diethylnitrosamine-induced HCC. Furthermore, we identified that tumour hypoxia was attenuated, as shown by reduced pimonidazole binding. Interestingly, hypoxic exposure markedly activated the PERK pathway in HCC cells in vitro, suggesting that PlGF inhibition may diminish PERK activation by improving oxygen delivery. We also found that PlGF expression is upregulated by different chemical UPR inducers via activation of the inositol-requiring enzyme 1 pathway in HCC cells. Conclusions: PlGF inhibition attenuates PERK activation, likely by tempering hypoxia in HCC via vessel normalisation. The UPR, in turn, is able to regulate PlGF expression, suggesting the existence of a feedback mechanism for hypoxia-mediated UPR that promotes the expression of the angiogenic factor PlGF. These findings have important implications for our understanding of the effect of therapies normalising tumour vasculature