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(Auto)Biografia de um bairro rural paulista: mistérios, olvidos, segredos = (Auto)Biography of a rural district in S o Paulo: mysteries, forgettings, secrets
Vangelista, Chiara
Educa??o , 2011,
Abstract: Mediante o cruzamento do caderno de campo com as entrevistas produzidas ao longo de uma pesquisa de história oral conduzida num bairro rural de Vale do Ribeira (SP), nos anos oitenta do século passado, o ensaio se apresenta como uma série de apontamentos sobre o vivido de uma pesquisadora no seu trabalho, os desentendimentos possíveis ocasionados pela presen a de um pesquisador numa comunidade camponesa, além dos olvidos e segredos que est o inseridos na trama da constru o de uma (auto)biografia no seio de uma coletividade. By crossing the field notebook with interviews produced along an oral history research conducted in a rural neighborhood of Vale do Ribeira (SP) in the eighties of last century, the essay brings up a series of notes concerning the experience of a researcher in her work, the friction caused by the possible presence of a researcher in a peasant community, and on the overlooked and the secrets that are embedded in the plot of the building of a collective (auto)biography within a collectivity.
A Distributed Approach to Interference Alignment in OFDM-based Two-tiered Networks
Marco Maso,Merouane Debbah,Lorenzo Vangelista
Mathematics , 2013, DOI: 10.1109/TVT.2013.2245516
Abstract: In this contribution, we consider a two-tiered network and focus on the coexistence between the two tiers at physical layer. We target our efforts on a long term evolution advanced (LTE-A) orthogonal frequency division multiple access (OFDMA) macro-cell sharing the spectrum with a randomly deployed second tier of small-cells. In such networks, high levels of co-channel interference between the macro and small base stations (MBS/SBS) may largely limit the potential spectral efficiency gains provided by the frequency reuse 1. To address this issue, we propose a novel cognitive interference alignment based scheme to protect the macro-cell from the cross-tier interference, while mitigating the co-tier interference in the second tier. Remarkably, only local channel state information (CSI) and autonomous operations are required in the second tier, resulting in a completely self-organizing approach for the SBSs. The optimal precoder that maximizes the spectral efficiency of the link between each SBS and its served user equipment is found by means of a distributed one-shot strategy. Numerical findings reveal non-negligible spectral efficiency enhancements with respect to traditional time division multiple access approaches at any signal to noise (SNR) regime. Additionally, the proposed technique exhibits significant robustness to channel estimation errors, achieving remarkable results for the imperfect CSI case and yielding consistent performance enhancements to the network.
Critical analysis of the manoeuvres proposed for the diagnosis of the tunnel carpal syndrome
R. Ramonda,L. Punzi,T. Vangelista,S. Todesco
Reumatismo , 2011, DOI: 10.4081/reumatismo.2002.156
Abstract: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. It is mainly due to the compression of median nerve at the wrist and it may be idiopathic or secondary to different rheumatic or non rheumatic diseases, including occupational activities. Since signs and symptoms of CTS are characteristic, a careful examination of the affected patient may be very satisfactory for the diagnosis, in particular by mean of some manoeuvres. In this review we described and commented the tests considered most useful in the diagnosis of CTS. We also analysed the diagnostic values of electromiography, the most important electrodiagnostic study for the CTS.
Role and Redirection of IgE against Cancer
Elisa A. Nigro,Antonio G. Siccardi,Luca Vangelista
Antibodies , 2013, DOI: 10.3390/antib2020371
Abstract: IgE is a highly elusive antibody class, yet a tremendously powerful elicitor of immune reactions. Despite huge efforts spent on the characterization and understanding of the IgE system many questions remain either unanswered or only marginally addressed. One above all relates to the role of IgE. A common doubt is based on whether IgE mode of action should only be relegated to anti-parasite immunity and allergic manifestations. In search for a hidden role of IgE, reports from several laboratories are described herein in which a natural IgE link to cancer or the experimental redirection of IgE against cancer have been investigated. Epidemiological and investigational studies are trying to elucidate a possible direct intervention of endogenous IgE against cancer, raising thus far no definitive evidence. Conversely, experimental approaches implementing several strategies and engineered IgE formats built up a series of convincing results indicating that cancer might be tackled by the effector functions of this immunoglobulin class. Because of its peculiar immune features, IgE may present a superior anti-tumor performance as compared to IgG. However, extreme care should be taken on how IgE-based anti-tumor approaches should be devised. Overall, IgE appears as a promising resource, likely destined to enrich the anti-cancer arsenal.
Cognitive Orthogonal Precoder for Two-tiered Networks Deployment
Marco Maso,Leonardo S. Cardoso,Merouane Debbah,Lorenzo Vangelista
Mathematics , 2013,
Abstract: In this work, the problem of cross-tier interference in a two-tiered (macro-cell and cognitive small-cells) network, under the complete spectrum sharing paradigm, is studied. A new orthogonal precoder transmit scheme for the small base stations, called multi-user Vandermonde-subspace frequency division multiplexing (MU-VFDM), is proposed. MU-VFDM allows several cognitive small base stations to coexist with legacy macro-cell receivers, by nulling the small- to macro-cell cross-tier interference, without any cooperation between the two tiers. This cleverly designed cascaded precoder structure, not only cancels the cross-tier interference, but avoids the co-tier interference for the small-cell network. The achievable sum-rate of the small-cell network, satisfying the interference cancelation requirements, is evaluated for perfect and imperfect channel state information at the transmitter. Simulation results for the cascaded MU-VFDM precoder show a comparable performance to that of state-of-the-art dirty paper coding technique, for the case of a dense cellular layout. Finally, a comparison between MU-VFDM and a standard complete spectrum separation strategy is proposed. Promising gains in terms of achievable sum-rate are shown for the two-tiered network w.r.t. the traditional bandwidth management approach.
Cognitive Interference Alignment for OFDM Two-tiered Networks
Marco Maso,Leonardo S. Cardoso,Merouane Debbah,Lorenzo Vangelista
Mathematics , 2013, DOI: 10.1109/SPAWC.2012.6292902
Abstract: In this contribution, we introduce an interference alignment scheme that allows the coexistence of an orthogonal frequency division multiplexing (OFDM) macro-cell and a cognitive small-cell, deployed in a two-tiered structure and transmitting over the same bandwidth. We derive the optimal linear strategy for the single antenna secondary base station, maximizing the spectral efficiency of the opportunistic link, accounting for both signal sub-space structure and power loading strategy. Our analytical and numerical findings prove that the precoder structure proposed is optimal for the considered scenario in the face of Rayleigh and exponential decaying channels.
Time-varying Clock Offset Estimation in Two-way Timing Message Exchange in Wireless Sensor Networks Using Factor Graphs
Aitzaz Ahmad,Davide Zennaro,Erchin Serpedin,Lorenzo Vangelista
Mathematics , 2012,
Abstract: The problem of clock offset estimation in a two-way timing exchange regime is considered when the likelihood function of the observation time stamps is exponentially distributed. In order to capture the imperfections in node oscillators, which render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed using a factor graph representation of the posterior density. Message passing using the max-product algorithm yields a closed form expression for the Bayesian inference problem.
A Factor Graph Approach to Clock Offset Estimation in Wireless Sensor Networks
Aitzaz Ahmad,Davide Zennaro,Erchin Serpedin,Lorenzo Vangelista
Mathematics , 2012,
Abstract: The problem of clock offset estimation in a two way timing message exchange regime is considered when the likelihood function of the observation time stamps is Gaussian, exponential or log-normally distributed. A parametrized solution to the maximum likelihood (ML) estimation of clock offset, based on convex optimization, is presented, which differs from the earlier approaches where the likelihood function is maximized graphically. In order to capture the imperfections in node oscillators, which may render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed by using a factor graph representation of the posterior density. Message passing using the max-product algorithm yields a closed form expression for the Bayesian inference problem. Several lower bounds on the variance of an estimator are derived for arbitrary exponential family distributed likelihood functions which, while serving as stepping stones to benchmark the performance of the proposed clock offset estimators, can be useful in their own right in classical as well Bayesian parameter estimation theory. To corroborate the theoretical findings, extensive simulation results are discussed for classical as well as Bayesian estimators in various scenarios. It is observed that the performance of the proposed estimators is fairly close to the fundamental limits established by the lower bounds.
Long-Range Communications in Unlicensed Bands: the Rising Stars in the IoT and Smart City Scenarios
Marco Centenaro,Lorenzo Vangelista,Andrea Zanella,Michele Zorzi
Computer Science , 2015,
Abstract: Connectivity is probably the most basic building block of the Internet of Things (IoT) paradigm. Up to know, the two main approaches to provide data access to the \emph{things} have been based either on multi-hop mesh networks using short-range communication technologies in the unlicensed spectrum, or on long-range, legacy cellular technologies, mainly 2G/GSM, operating in the corresponding licensed frequency bands. Recently, these reference models have been challenged by a new type of wireless connectivity, characterized by low-rate, long-range transmission technologies in the unlicensed sub-GHz frequency bands, used to realize access networks with star topology which are referred to a \emph{Low-Power Wide Area Networks} (LPWANs). In this paper, we introduce this new approach to provide connectivity in the IoT scenario, discussing its advantages over the established paradigms in terms of efficiency, effectiveness, and architectural design, in particular for the typical Smart Cities applications.
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