1,528 research outputs found
Distributed AOA-based source positioning in NLOS with sensor networks
©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper focuses on the problem of positioning a
source using angle-of-arrival measurements taken by a wireless
sensor network in which some of the nodes experience non lineof-sight
(LOS) propagation conditions. In order to mitigate the
errors induced by the nodes in NLOS, we derive an algorithm
that combines the expectation-maximization algorithm with a
weighted least-squares estimation of the source position so that
the nodes in NLOS are eventually identified and discarded.
Moreover, a distributed version of this algorithm based on a
diffusion strategy that iteratively refines the position estimate
while driving the network to a consensus is presented.Peer ReviewedPostprint (author's final draft
Behavioral aspects and predation of seeds of Cardiospermum grandiflorum Swartz (Sapindaceae) by Cissoanthonomus tuberculipennis Hustache (Coleoptera: Curculionidae)
For the first time in Brazil, the weevil Cissoanthonomus tuberculipennis Hustache, 1939 (Coleoptera: Curculionidae) are reported preying on seeds of Cardiospermum grandiflorum Swartz (Sapindaceae). Observations are presented on oviposition and larval behavior, pupation site, and adult emergence. Photos of host plant, egg, larva, pupa and adult are provided
The underlying structure of the Personality Inventory for DSM-5 (PID-5): a general factor of personality psychopathology
BACKGROUND: The psychopathology of personality is currently undergoing a paradigm shift from a categorical to a dimensional approach. This work aimed to study the underlying structure of pathological personality traits of the DSM-5 Alternative Model for Personality Disorders (AMPD). For this purpose, the internal structure of a version of the Personality Inventory for the DSM-5 [PID-5] was examined by a Confirmatory Factor Analysis. This version assesses the five higher-order pathological personality domains (Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism) and the 25 lower-order pathological personality facets through a reduced number of items. Four alternative models were compared: five-factor oblique; second-order (five first-order factors and one second-order factor); bifactor (five specific factors and a general factor), and one-factor. PARTICIPANTS AND PROCEDURE: We worked with an Argentinean sample of n= 525 subjects from the general population who answered the Argentine version of the PID-5. RESULTS: The five-factor model was slightly superior to the second order model, and the bifactor model presented the best fit. CONCLUSIONS: These findings, while preliminary, suggest that the PID-5 facets could reflect five specific pathological personality traits (which correspond to AMPD domains) but also a general factor (which would reflect a general propensity for psychopathology).Fil: Montes, Silvana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Psicología Básica, Aplicada y Tecnología. Universidad Nacional de Mar del Plata. Facultad de Psicología. Instituto de Psicología Básica, Aplicada y Tecnología.; ArgentinaFil: Sanchez, Roberto Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Psicología Básica, Aplicada y Tecnología. Universidad Nacional de Mar del Plata. Facultad de Psicología. Instituto de Psicología Básica, Aplicada y Tecnología.; Argentin
Interpreting Encoding and Decoding Models
Encoding and decoding models are widely used in systems, cognitive, and
computational neuroscience to make sense of brain-activity data. However, the
interpretation of their results requires care. Decoding models can help reveal
whether particular information is present in a brain region in a format the
decoder can exploit. Encoding models make comprehensive predictions about
representational spaces. In the context of sensory systems, encoding models
enable us to test and compare brain-computational models, and thus directly
constrain computational theory. Encoding and decoding models typically include
fitted linear-model components. Sometimes the weights of the fitted linear
combinations are interpreted as reflecting, in an encoding model, the
contribution of different sensory features to the representation or, in a
decoding model, the contribution of different measured brain responses to a
decoded feature. Such interpretations can be problematic when the predictor
variables or their noise components are correlated and when priors (or
penalties) are used to regularize the fit. Encoding and decoding models are
evaluated in terms of their generalization performance. The correct
interpretation depends on the level of generalization a model achieves (e.g. to
new response measurements for the same stimuli, to new stimuli from the same
population, or to stimuli from a different population). Significant decoding or
encoding performance of a single model (at whatever level of generality) does
not provide strong constraints for theory. Many models must be tested and
inferentially compared for analyses to drive theoretical progress.Comment: 19 pages, 2 figures, author preprin
Archive, management of documents and information
A gestão de documentos arquivísticos é um procedimento fundamental na vida de uma
empresa pública ou privada. Para tomar decisões, recuperar a informação e preservar a memória institucional é preciso estabelecer um conjunto de práticas que garanta a organização e preservação dos arquivos. Este artigo aborda os principais aspectos, teóricos e práticos, que devem ser levados em consideração na implantação da gestão de documentos e os desafios que as instituições brasileiras, públicas ou privadas, ainda precisam enfrentar para gerenciar e preservar seus acervos documentais.
_____________________________________________________________________________________ ABSTRACTThe management of documents is a fundamental procedure in public or private enterprises. To take decisions, to recuperate informations and to preserve the institutional memory is necessary to establish a combined practice that can guaranty the organization and preservation of the archives. This article analyses the most important aspects of theory and practice, that must be considerate in implanting the management of documents and the challenges that Brazilian institutions, publics or private, still must confront for manage and preserve their amounts of documents
Aliskiren, a renin inhibitor, downregulates TNF-α-induced tissue factor expression in HUVECS
Angiotensin (Ang)II, the effector arm of the locally active renin—angiotensin system (RAS), modulates Tissue Factor (TF), the principal initiator of blood coagulation and a key promoter of atherothrombotic events. Consistent with that knowledge, previous data showed inhibitory properties of angiotensin-converting enzyme inhibitor (ACEI)s and angiotensin II type-1 receptor blocker (ARB)s, but no data are available about the effect of renin inhibition. We aimed to evaluate whether aliskiren, a direct renin inhibitor (DRI), modulates TNF-α-stimulated TF expression in cultured human umbilical vein endothelial cells (HUVECs). Zofenopril, an ACEI, and olmesartan, an ARB, were the controls. HUVECs were incubated with experimental drugs (1 nM) 30 min prior to TNF-α stimulation (0.1 ng/ml × 4 h). Main evaluation variables were procoagulant activity (single-stage clotting assay), TF antigen (ELISA) and mRNA expression (real-time polymerase chain reaction) in cell lysates. TNF-α stimulated procoagulant activity and increased TF antigen and mRNA expression. Aliskiren inhibited TNF-α-mediated TF stimulation; zofenopril and olmesartan exerted a comparable effect. We conclude that aliskiren, a DRI, downregulates TNF-α-stimulated TF expression in HUVECs, possibly as a reflection of endothelial renin activation by the cytokine
Parameter estimation in wireless sensor networks with faulty transducers: a distributed EM approach
We address the problem of distributed estimation of a vector-valued parameter performed by a wireless sensor network in the presence of noisy observations which may be unreliable due to faulty transducers. The proposed distributed estimator is based on the Expectation-Maximization (EM) algorithm and combines consensus and diffusion techniques: a term for information diffusion is gradually turned off, while a term for updated information averaging is turned on so that all nodes in the network approach the same value of the estimate. The proposed method requires only local exchanges of information among network nodes and, in contrast with previous approaches, it does not assume knowledge of the a priori probability of transducer failures or the noise variance. A convergence analysis is provided, showing that the convergent points of the centralized EM iteration are locally asymptotically convergent points of the proposed distributed scheme. Numerical examples show that the distributed algorithm asymptotically attains the performance of the centralized EM method.Peer ReviewedPreprin
Mamelucos (São Paulo y São Vicente, siglos XVI y XVII)
El artículo analiza los mamelucos (mestizos de indios derivados de la mezcla con los portugueses) de São Paulo y São Vicente, del Estado de Brasil, durante los siglos XVI y XVII. Basado sobre todo en crónicas e informes de viajeros, subraya que los mamelucos fueron identificados por terceros y que las formas de identificación de los mamelucos siguieron criterios religiosos, políticos y familiares. Eran un grupo heterogéneo y cambiante en el tiempo y el espacio. La fluidez de las formas de identificación del grupo debe entenderse en su dimensión relacional y en razón de los enunciados.The article analyzes the Mameluks (mixed race individuals with an Indian mother and a Portuguese father) of São Paulo and São Vicente, Brazil, during the 16th and 17th centuries. Based mainly on chronicles and traveler reports, it highlights that the Mameluks were identified as a social category by other social agents and that the forms of identification followed religious, political and kinship criteria. They were a heterogeneous and mutant group in time and space. The fluidity of the forms of group identification must be understood in its relational dimension and according to each discourse.L'article analyse les Mamelouks (métis indiens issue du métissage avec les Portugais) de São Paulo et São Vicente, dans l'État du Brésil, au cours des XVIe et XVIIe siècles. Basé principalement sur des chroniques et des rapports de voyageurs, il souligne que les Mamelouks ont été identifiés par des tiers et que les formes d'identification ont suivi des critères religieux, politiques et familiaux. Ils formaient un groupe hétérogène, changeant dans le temps et l'espace. La fluidité des formes d'identification du groupe doit être comprise dans sa dimension relationnelle et en raison des déclarations
Improvement in Hemodynamic Responses to Metaboreflex Activation after One Year of Training in Spinal Cord Injured Humans
Spinal cord injured (SCI) individuals show an altered hemodynamic response to metaboreflex activation due to a reduced capacity to vasoconstrict the venous and arterial vessels below the level of the lesion. Exercise training was found to enhance circulating catecholamines and to improve cardiac preload and venous tone in response to exercise in SCI subjects. Therefore, training would result in enhanced diastolic function and capacity to vasoconstrict circulation. The aim of this study was to test the hypothesis that one year of training improves hemodynamic response to metaboreflex activation in these subjects. Nine SCI individuals were enrolled and underwent a metaboreflex activation test at the beginning of the study (T0) and after one year of training (T1). Hemodynamics were assessed by impedance cardiography and echocardiography at both T0 and T1. Results show that there was an increment in cardiac output response due to metaboreflex activity at T1 as compared to T0 (545.4 ± 683.9 mL · min(-1) versus 220.5 ± 745.4 mL · min(-1), P < 0.05). Moreover, ventricular filling rate response was higher at T1 than at T0. Similarly, end-diastolic volume response was increased after training. We concluded that a period of training can successfully improve hemodynamic response to muscle metaboreflex activation in SCI subjects
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