489 research outputs found

    Multi-threaded Simulation of 4G Cellular Systems within the LTE-Sim Framework

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    Nowadays, an always increasing number of researchers and industries are putting a large effort in the design and the implementation of protocols, algorithms, and network architectures targeted at the the emerging 4G cellular technology. In this context, multi-core/multi-processor simulation tools can accelerate their activities by drastically reducing the time required to simulate complex scenarios. Unfortunately, today's available tools are mostly single-threaded and they cannot exploit the performance gain offered by parallel programming approaches. To bridge this gap, we have significantly upgraded the LTE-Sim framework by implementing a concurrent scheduling algorithm, namely the Multi-Master Scheduler, aimed at efficiently handling events in a parallel manner, while guaranteeing the correct execution of the simulation itself. Experimental results will demonstrate the effectiveness of our proposal and the performance gain that can be achieved with respect to other classical event scheduling algorithms

    Molecular dissection of Phaseolus vulgaris polygalacturonase-inhibiting protein 2 reveals the presence of hold/release domains affecting protein trafficking toward the cell wall

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    The plant endomembrane system is massively involved in the synthesis, transport and secretion of cell wall polysaccharides and proteins; however, the molecular mechanisms underlying trafficking toward the apoplast are largely unknown. Besides constitutive, the existence of a regulated secretory pathway has been proposed. A polygalacturonase inhibitor protein (PGIP2), known to move as soluble cargo and reach the cell wall through a mechanism distinguishable from default, was dissected in its main functional domains (A, B, C, D), and C sub-fragments (C1–10), to identify signals essential for its regulated targeting. The secretion patterns of the fluorescent chimeras obtained by fusing different PGIP2 domains to the green fluorescent protein (GFP) were analyzed. PGIP2 N-terminal and leucine-rich repeat domains (B and C, respectively) seem to operate as holding/releasing signals, respectively, during PGIP2 transit through the Golgi. The B domain slows down PGIP2 secretion by transiently interacting with Golgi membranes. Its depletion leads, in fact, to the secretion via default (Sp2-susceptible) of the ACD-GFP chimera faster than PGIP2. Depending on its length (at least the first 5 leucine-rich repeats are required), the C domain modulates B interaction with Golgi membranes allowing the release of chimeras and their extracellular secretion through a Sp2 independent pathway. The addition of the vacuolar sorting determinant Chi to PGIP2 diverts the path of the protein from cell wall to vacuole, suggesting that C domain is a releasing rather than a cell wall sorting signal

    Vacuolar system distribution in Arabidopsis tissues, visualized using GFP fusion proteins

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    Green fluorescent protein (GFP) allows the direct visualization of gene expression and the subcellular localization of fusion proteins in living cells. The localization of different GFP fusion proteins in the secretory system was studied in stably transformed Arabidopsis plants cv. Wassilewskaja. Secreted GFP (SGFP) and GFP retained in the ER (GFP‐KDEL) confirmed patterns already known, but two vacuolar GFPs (GFP‐Chi and Aleu‐GFP) labelled the Arabidopsis vacuolar system for the first time, the organization of which appears to depend on cell differentiation. GFP stability in the vacuoles may depend on pH or degradation, but these vacuolar markers can, nevertheless, be used as a tool for physiological studies making these plants suitable for mutagenesis and gene‐tagging experiment

    Spontaneous Resorption of an Occipital Meningocele: Computed Tomography and Magnetic Resonance Imaging Evaluation

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    Cranial meningocele is a very rare variant of encephalocele. Meningocele can be associated with other disorders and may cause complications. Therapy is usually based on surgical treatment. To our knowledge, we describe the first case of spontaneous resorption of an occipital meningocele in a full-term newborn boy. A full-term newborn was noted to have a large non-skin covered, semitransparent cystic lump in the occipital bone. He underwent computed tomography and a diagnosis of meningocele was proposed. After a few hours, the cystic lump spontaneously readsorbed. After 1 week the patient underwent magnetic resonance. Histology confirmed the diagnosis

    Epoetin alfa increases frataxin production in Friedreich's ataxia without affecting hematocrit.

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    Objective of the study was to test the efficacy, safety, and tolerability of two single doses of Epoetin alfa in patients with Friedreich's ataxia. Ten patients were treated subcutaneously with 600 IU/kg for the first dose, and 3 months later with 1200 IU/kg. Epoetin alfa had no acute effect on frataxin, whereas a delayed and sustained increase in frataxin was evident at 3 months after the first dose (+35%; P < 0.05), and up to 6 months after the second dose (+54%; P < 0.001). The treatment was well tolerated and did not affect hematocrit, cardiac function, and neurological scale. Single high dose of Epoetin alfa can produce a considerably larger and sustained effect when compared with low doses and repeated administration schemes previously adopted. In addition, no hemoglobin increase was observed, and none of our patients required phlebotomy, indicating lack of erythropoietic effect of single high dose of erythropoietin. © 2010 Movement Disorder Society

    Multicast and Broadcast Services Over Mobile Networks: A Survey on Standardized Approaches and Scientific Outcomes

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    Due to the increasing demand for pervasive video and broadcast-like applications, multicast and broadcast communications are expected to assume an important role in upcoming 5G systems. The current research trend is trying to reuse, extend, or adapt reference transmission strategies already designed for the conventional 4G technology. Nevertheless, apart the two reference and standardized methodologies, i.e., multimedia broadcast/multicast service and single cell-point to multipoint, many technical extensions and novel solutions were published in the literature so far. Therefore, in order to provide a clear overview on available solutions (already standardized or simply extending conventional approaches), the present work provides a comprehensive survey on network architectures, communication protocols, transmission strategies, and optimization algorithms to improve the performance of multicast communications over mobile radio systems. The core of the conducted study represents a structured taxonomy, able to properly classify scientific contributions based on their reference standard, targeted goal, addressed methodology, considered application domain, and obtained results. Taking into account this taxonomy, more than one hundred of scientific contributions are presented, classified, and reviewed. The study of the state-of-the-art is further enhanced with the discussion on important lessons learned, which clearly highlight the pros and cons of any investigated approach. A focus is also provided on the main issues on long term evolution multicasting that need to be better investigated, and determine the possible future research directions on this subject. The final goal of this paper is to support research activities devoted to the identification of promising methodologies, that efficiently support the delivery of real-time and on-demand video contents in a TV-like fashion

    Design of Coordinated HeNB Deployments

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    Uncoordinated deployment of HeNBs has been widely considered, in the research community. However, due to economic or physical constraints, a coordinated deployment of HeNBs can also be considered. This work studies a selected examples of HeNB deployment. We consider the deployment of four Enterprise HeNB which serve up to 8 simultaneous users, in a building, with a geometry of 5x5 apartments. From the theoretical study on the average SINR, we have learned that the smaller the apartment areas are the higher the values for the average SINR are. The performance evolution of the system focuses on the values obtained for the average goodput, Packet Loss Ratio (PLR) and delay for the Proportional Fair, Frame Level Scheduler (FLS) and Exponential Rule (EXPRule) schedulers, with users using a video and a best effort flows at the same time. For the video flows the maximum average goodput was obtained with the FLS scheduler, but when the PLR is taken into account the EXPRule present a slight advantage. In the case of the BE flows, the EXPRule present the best performance. But the main lesson learned is that it is possible to operate a coordinated HeNB deployments without setting the transmitter power of the HeNBs to the maximum value, which can be a step to achieve a greener system.info:eu-repo/semantics/publishedVersio

    Folk medicine used to heal malaria in Calabria (southern Italy)

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    In Italy, malaria was an endemic disease that was eradicated by the mid-20th century. This paper evaluates the prophylactic and therapeutic remedies used by folk medicine to cure malaria in Calabria (southern Italy)

    Performance Evaluation and Packet Scheduling in HeNB Deployments

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    The unsupervised and chaotic deployment of Home eNBs (HeNBs) is leading to high levels of interference. To understand the behaviour of the interference of these uncoordinated deployments is vital to reach significant capacity improvement and also to explore opportunities to save energy. This paper considers high and middle interference level scenarios, with a maximum of four users per cell. HeNBs indoor deployed is considered within building. We theoretically analyse the traffic performance of this scenario through the study of the Signal-to-Interference-plus-Noise-Ratio (SINR). Through the use of the LTE-Sim simulator one obtains the quality indicators for two flows that are being utilised by the users. Video and best effort are studied, while varying the transmitter power and the areas of the apartments. The achieved SINR is higher (around 10 dBm) when the area of the cells is smaller. The variation of the transmitter power of the HeNBs does not present any significant impact. Noticeable throughout the simulations is observed that is possible to operate the system without setting the transmitter power of HeNBs to the maximum value at both interference levels. Simulation results also show that with the considered flows is possible to serve the maximum number of four users per HeNB with high quality. This statement is confirmed by the maximum achieved Packet Loss Ratio for video with a value of value of 1.6 %, which is lower than the maximum of 2 % indicated by the 3GPP. Taking into account the obtained results it is possible to promote a reduction in energy consumption of the HeNBs without penalizing the service quality.info:eu-repo/semantics/publishedVersio
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