Structural properties of optimal coordinate-convex policies for CAC with nonlinearly-constrained feasibility regions

Necessary optimality conditions for Call Admission Control (CAC) problems with nonlinearly-constrained feasibility regions and two classes of users are derived. The policies are restricted to the class of coordinate-convex policies. Two kinds of structural properties of the optimal policies and their robustness with respect to changes of the feasibility region are investigated: 1) general properties not depending on the revenue ratio associated with the two classes of users and 2) more specific properties depending on such a ratio. The results allow one to narrow the search for the optimal policies to a suitable subset of the set of coordinate-convex policies

Detection and Combining Techniques for Asynchronous Random Access with Time Diversity

Asynchronous random access (RA) protocols are particularly attractive for their simplicity and avoidance of tight synchronization requirements. Recent enhancements have shown that the use of successive interference cancellation (SIC) can largely boost the performance of these schemes. A further step forward in the performance can be attained when diversity combining techniques are applied. In order to enable combining, the detection and association of the packets to their transmitters has to be done prior to decoding. We present a solution to this problem, that articulates into two phases. Non-coherent soft-correlation as well as interference-aware soft-correlation are used for packet detection. We evaluate the detection capabilities of both solutions via numerical simulations. We also evaluate numerically the spectral efficiency achieved by the proposed approach, highlighting its benefits.Comment: 6 pages, 7 figures. Work has been submitted to the 11th International ITG Conference on Systems, Communications and Coding 201

A Source Routing Algorithm Based on CGR for DTN-Nanosatellite Networks

The number of nanosatellites orbiting around the Earth is increasing year after year. Nanosatellite constellations can be deployed to cover even larger areas. However, data exchange among nanosatellites is not trivial, especially due to the required hardware components related to the limited size and weight. Moreover, in some cases, contacts between nanosatellites and ground stations cannot always be guaranteed. The Delay and Disruption Tolerant Networking (DTN) paradigm allows storing data in nanosatellite and ground station buffers until the contact with the next hop is available. Routing in this kind of network is a crucial aspect. Delivery times are larger compared to a \u201cclassical\u201d network due to the time that data have to wait inside intermediate node buffers and to the limitation of available resources, especially on-board nanosatellites. The adoption of a smart routing strategy can contribute relieving this gap. In this paper, we propose S-CGR, a Source routing algorithm based on the Contact Graph Routing (CGR). It computes a routing path from source to destination nodes for each bundle, which is the data unit in DTN networks. S-CGR considers static and known a priori information about contacts (begin times, end times, and overall contact volumes) and dynamic information about nanosatellite buffer occupancies and available contact volumes. The complete source/destination paths are stored in the bundles. Intermediate nodes read the routin

SatSel: A Satellite Selection Algorithm to reduce delivery time in DTN-Nanosatellite Networks for Internet Access in Rural Areas.

There are some different ways to connect rural areas to the Internet. One of these provides the use of a nanosatellite constellation. This type of network allows people in rural areas to enjoy all services the Internet can offer keeping low the cost of Internet access. One of the critical aspect is related to the delivery time, because LEO satellite links are not always up. This means that the system must be able to deal with periodic disruptions and high delays in the path from the source to the destination, considering that data could be stored in nanosatellite, Internet gateway (also called hot spot), and rural gateway (also called cold spot) buffers also for several seconds or minutes waiting to be forwarded. In the path from rural areas to the Internet, it is possible to reduce data delivery time acting on rural gateways. We propose SatSel: a selection algorithm which allows the cold spots to choose the nanosatellite to whom upload data in order to reduce the data delivery tim

Expression of non-visual opsins Opn3 and Opn5 in the developing inner retinal cells of birds. Light-responses in Müller Glial Cells

The avian retina is composed of different types of photoreceptors responsible for image and non-image forming tasks: the visual photoreceptor cells (cones and rods), the melanopsin-expressing intrinsically photoresponsive retinal ganglion cells (ipRGCs) and horizontal cells. Furthermore, the non-visual opsins Opn3 (encephalopsin/panaopsin) and Opn5 (neuropsin) have been shown to be expressed in the vertebrate inner retina, responding to blue (BL) and UV light, respectively. Here we investigated the expression and localization of Opn3 and Opn5 in the developing chick retina at different embryonic days (E) as well as in primary cultures of retinal Müller glial cells (MCs). Opn3 and Opn5 mRNAs and proteins appeared as early as E10 although traces of Opn3- and Opn5-like proteins were seen earlier by E7 in the forming RGC layer and in glial cells extending throughout the developing nuclear layer. Later on, at postnatal days 1–10 (PN1–10) a significant expression of Opn3 was observed in inner retinal cells and processes in plexiform layers, together with expression of the glial markers glutamine synthetase (GS) and the glial fibrillary acidic protein (GFAP). Opn3 and Opn5 were found to be expressed in primary MC cultures prepared at E8 and kept for 2 weeks. In addition, significant effects of BL exposure on Opn3 expression and subcellular localization were observed in MCs as BL significantly increased its levels and modified its nuclear location when compared with dark controls, through a mechanism dependent on protein synthesis. More importantly, a subpopulation of MCs responded to brief BL pulses by increasing intracellular Ca2+ levels; whereas light-responses were completely abolished with the retinal bleacher hydroxylamine pretreatment. Taken together, our findings show that these two opsins are expressed in inner retinal cells and MCs of the chicken retina at early developmental phases and remain expressed in the mature retina at PN days. In addition, the novel photic responses seen in MCs may suggest another important role for the glia in retinal physiology.Fil: Rios, Maximiliano Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Marchese, Natalia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Guido, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentin

Nanosatellite-5G Integration in the Millimeter Wave Domain: A Full Top-Down Approach

This paper presents a novel network architecture for an integrated nanosatellite (nSAT)-5G system operating in the millimeter-wave (mmWave) domain. The architecture is realized adopting a delay/disruption tolerant networking (DTN) approach allowing end users to adopt standard devices. A buffer aware contact graph routing algorithm is designed to account for the buffer occupancy of the nSATs and for the connection planning derived from their visibility periods. At the terrestrial uplink, a coded random access is employed to realize a high-capacity interface for the typically irregular traffic of 5G users, while, at the space uplink, the DTN architecture is combined with the contention resolution diversity slotted Aloha protocol to match the recent update of the DVB-RCS2 standard. To achieve a reliable testing of the introduced functionalities, an accurate analysis of the statistic of the signal to interference-plus-noise ratio and of the capture probability at each mmWave link is developed by including interference, shadowing, fading, and noise. The application of the designed architecture to data transfer services in conjunction with possible delay reduction strategies, and an extension to inter-satellite communication, are finally presented by estimating the resulting loss/delay performance through a discrete-time discrete-event platform based on the integration of Matlab with Network Simulator 3

Lights and shadows of schizophrenia therapy research : Lessons from oral risperidone and olanzapine

Peer reviewedPostprintPostprin

A 15-Year-Old Boy with Anterior Chest Pain, Progressive Dyspnea, and Subcutaneous Emphysema of the Neck

We describe the case of an adolescent who was admitted to the hospital because of sudden occurrence of chest pain, dyspnea and subcutaneous emphysema. On admission, physical examination revealed subcutaneous crepitations in the superior part of the rib cage, and auscultation of the chest showed widespread wheezing. The radiological assessment confirmed the diagnosis of pneumomediastinum and pneumothorax. A follow-up CT scan performed one week after the admission showed almost complete resolution of the radiological alterations. At the following visits, the patient was asymptomatic, but reported to have suffered from frequent episodes of rhinorrea, sneezing, nasal blockage, and sometimes, chest tightness, especially during exposure to pets and/or windy weather. Skin prick testing showed sensitivities to dermatophagoides pteronyssinus and farinae, grass pollen and dog dander. Spirometry documented significant improvement in lung function after short-acting bronchodilator, allowing for the diagnosis of asthma to be made. Although pneumomediastinum may be a complication of various respiratory diseases, including asthma, it has never been reported as the first presentation of underlying bronchial asthma. Herein, the physiopathological mechanisms, the diagnostic procedures and treatment of pneumomediastinum in asthma are discussed. We suggest that the diagnosis of asthma should be considered in the differential diagnosis of pneumomediastinum in adolescence