Lobby index as a network centrality measure

We study the lobby index (l-index for short) as a local node centrality measure for complex networks. The l-inde is compared with degree (a local measure), betweenness and Eigenvector centralities (two global measures) in the case of biological network (Yeast interaction protein-protein network) and a linguistic network (Moby Thesaurus II). In both networks, the l-index has poor correlation with betweenness but correlates with degree and Eigenvector. Being a local measure, one can take advantage by using the l-index because it carries more information about its neighbors when compared with degree centrality, indeed it requires less time to compute when compared with Eigenvector centrality. Results suggests that l-index produces better results than degree and Eigenvector measures for ranking purposes, becoming suitable as a tool to perform this task.Comment: 11 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1005.480

Step frequency waveform design and analysis using the ambiguity function

This thesis investigates the use of the step frequency waveform, its design and analysis using the ambiguity function. The step frequency waveform consists of a series of N pulses each with a pulse width of z, and whose frequency is increased from pulse to pulse in steps of delta f. A design procedure for detection of small targets with a surface (land or sea) based step frequency radar employing a high pulse repetition frequency (PRF) waveform is developed. The proposed method determines the waveform parameters of given radar specifications. A simple graphical implementation as well as a computer implementation are presented. The theoretical dimensions of the step frequency waveform are defined and verified for some waveforms with parameters similar to the waveform of interest. Finally, the ambiguity function is used to analyze the step frequency waveform.http://archive.org/details/stepfrequencywav00soarLieutenant, Portuguese Nav

Mapas conceituais Com Erros: Uma Abordagem Prática e Rápida Para a Avaliação Diagnóstica

This article proposes an innovative approach to diagnostic assessment. It employs concept maps with errors as an alternative to overcome challenges often faced by teachers when requesting students to create their own maps. These challenges include students’ lack of training in concept mapping, simplified planning of assessment activities with concept maps, and delays in feedback delivery by teachers. Grounded in the Cognitive Load Theory and considering operational aspects related to teachers’ time availability, the article introduces, discusses, and tests the proposal of concept maps with errors, wherein the teacher creates the map on the subject under study and intentionally includes errors. A practical application during the emergency remote teaching validates this alternative, even under challenging conditions. Diagnostic assessment with concept maps with errors emerges as a practical, fast, and robust solution, appealing for overcoming obstacles and providing significant benefits in pedagogical practice.Este artigo propõe uma abordagem inovadora para a avaliação diagnóstica. Ela utiliza mapas conceituais com erros como alternativa para superar desafios frequentemente enfrentados pelos professores ao solicitarem que os alunos elaborem seus próprios mapas. Esses desafios incluem a falta de treinamento dos alunos na técnica de mapeamento conceitual, o planejamento simplificado das atividades avaliativas com mapas e a demora na entrega de devolutivas por parte dos professores. Fundamentando-se na Teoria da Carga Cognitiva e considerando os aspectos operacionais relacionados à disponibilidade de tempo dos professores, o artigo apresenta, discute e testa a proposta dos mapas conceituais com erros, na qual o professor cria o mapa sobre o tema em estudo e inclui erros intencionalmente. Uma aplicação prática durante o ensino remoto emergencial valida essa alternativa, mesmo em condições desafiadoras. A avaliação diagnóstica com mapas conceituais com erros emerge como uma solução prática, rápida e robusta. Ela é atraente para superar obstáculos e proporcionar benefícios significativos na prática pedagógica

A theta projection model for compressive creep behaviour of refractories at high temperature: application to alumina-spinel

Thermomechanical loads are normally applied to refractory materials throughout their service life whichever is their practical use (e.g. steel ladle, rotary kiln furnaces). Among all the phenomena that the refractories are exposed to, the influence of creep behaviour is essential in determining their performance. Creep of refractories is usually represented by simple creep laws such as Norton-Bailey, which lack the capacity for generalization. The theta projection creep method, on the other hand, was proposed in the twentieth century to predict the creep of metals and alloys across different temperatures and stresses. The model is represented by one exponential equation capable of representing the complete creep curve, and coefficients that are temperature and stress-dependent, thus enabling the representation of complex nonlinear creep behaviour. Since refractories have similar creep responses to metals, the theta projection creep model is validated to characterize the compressive creep behaviour of alumina-spinel refractories at temperatures between 1200 and 1500 °C. Creep data from steady-state and transient temperature creep tests are used to calibrate the model. A regression by the least square method is applied to calculate the model’s parameters. The model shows good flexibility in fitting the test data of the alumina-spinel refractory over the three creep stages. A temperature and stress dependence model is derived for the theta coefficients, reducing the number of material parameters necessary to describe the material's behaviour. The experimental creep curves are presented, as well as the curves resulting from the identified parameters. The implications of the chosen creep data set on the definition of the model and its adequacy for this novel application are discussed.This work was supported by the funding scheme of the European Commission, Marie SkłodowskaCurie Actions Innovative Training Networks in the frame of the project ATHOR—Advanced THermomechanical multi scale mOdelling of Refractory linings 764987 Grant. This work was partly fnanced by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB / 04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020. The authors acknowledge the colleagues from Montanuniversitaet in Leoben, S. Samadi and D. Gruber for the meaningful discussions. The authors would like to thank the reviewer for the insightful comments and suggestions, and the valuable discussion proposed, which helped to improve the quality of the manuscrip

Polyvinylpyrrolidone Nanofibers Incorporating Mesoporous Bioactive Glass for Bone Tissue Engineering

Publisher Copyright: © 2023 by the authors.Composite biomaterials that combine osteoconductive and osteoinductive properties are a promising approach for bone tissue engineering (BTE) since they stimulate osteogenesis while mimicking extracellular matrix (ECM) morphology. In this context, the aim of the present research was to produce polyvinylpyrrolidone (PVP) nanofibers containing mesoporous bioactive glass (MBG) 80S15 nanoparticles. These composite materials were produced by the electrospinning technique. Design of experiments (DOE) was used to estimate the optimal electrospinning parameters to reduce average fiber diameter. The polymeric matrices were thermally crosslinked under different conditions, and the fibers’ morphology was studied using scanning electron microscopy (SEM). Evaluation of the mechanical properties of nanofibrous mats revealed a dependence on thermal crosslinking parameters and on the presence of MBG 80S15 particles inside the polymeric fibers. Degradation tests indicated that the presence of MBG led to a faster degradation of nanofibrous mats and to a higher swelling capacity. The assessment of in vitro bioactivity in simulated body fluid (SBF) was performed using MBG pellets and PVP/MBG (1:1) composites to assess if the bioactive properties of MBG 80S15 were kept when it was incorporated into PVP nanofibers. FTIR and XRD analysis along with SEM–EDS results indicated that a hydroxy-carbonate apatite (HCA) layer formed on the surface of MBG pellets and nanofibrous webs after soaking in SBF over different time periods. In general, the materials revealed no cytotoxic effects on the Saos-2 cell line. The overall results for the materials produced show the potential of the composites to be used in BTE.publishersversionpublishe

A tree-based approach for modelling interception loss from evergreen oak Mediterranean savannas

Evaporation of rainfall intercepted by tree canopies is usually an important part of the overall water balance of forested catchments and there have been many studies dedicated to measuring and modelling rainfall interception loss. These studies have mainly been conducted in dense forests; there have been few studies on the very sparse forests which are common in dry and semi-arid areas. Water resources are scarce in these areas making sparse forests particularly important. Methods for modelling interception loss are thus required to support sustainable water management in those areas. In very sparse forests, trees occur as widely spaced individuals rather than as a continuous forest canopy. We therefore suggest that interception loss for this vegetation type can be more adequately modelled if the overall forest evaporation is derived by scaling up the evaporation from individual trees. The evaporation rate for a single tree can be estimated using a simple Dalton-type diffusion equation for water vapour as long as its surface temperature is known. From theory, this temperature is shown to be dependent upon the available energy and windspeed. However, the surface temperature of a fully saturated tree crown, under rainy conditions, should approach the wet bulb temperature as the radiative energy input to the tree reduces to zero. This was experimentally confirmed from measurements of the radiation balance and surface temperature of an isolated tree crown. Thus, evaporation of intercepted rainfall can be estimated using an equation which only requires knowledge of the air dry and wet bulb temperatures and of the bulk tree-crown aerodynamic conductance. This was taken as the basis of a new approach for modelling interception loss from savanna-type woodland, i.e. by combining the Dalton-type equation with the Gash’s analytical model to estimate interception loss from isolated trees. This modelling approach was tested using data from two Mediterranean savanna-type oak woodlands in southern Portugal. For both sites, simulated interception loss agreed well with the observations indicating the adequacy of this new methodology for modelling interception loss by isolated trees in savanna-type ecosystems. Furthermore, the proposed approach is physically based and requires only a limited amount of data. Interception loss for the entire forest can be estimated by scaling up the evaporation from individual trees accounting for the number of trees per unit area.info:eu-repo/semantics/publishedVersio

Analysis of familial incidence of non-syndromic cleft lip and palate in a Brazilian population

Background: The purpose of this study is to follow the familial incidence of non-syndromic or isolated cleft lip, with or without cleft palate (NSCL/P), and to analyze the relationships between the type of NSCL/P in the affected individual and his/her parent, looking at children in the first grade. Material and Methods: To investigate the familial incidence of NSCL/P we analyzed the records of 185 patients from 2004-2008, retrospectively. Detailed histories were collected regarding the familial incidence of NSCL/P. For the 185 individuals, the relationship between the type of NSCL/P and the sociodemographic and personal characteristics of the affected person and her/his cleft relatives was obtained. Results: The individuals were 42 carriers of CL, 109 with CLP (joined in one group) and 34 with CP (p<0.001). Of the total of participants, 65 (35.13%) presented a positive history of cleft in their families and 120 (64.86%) presented a negative history (p<0.001). There were differences between the cleft groups according to types of cleft and positive familial history (p<0.001). In both groups, the relatives with higher incidence of NSCL/P were cousins, with the same pattern of distribution between the two groups (p=0.175). Conclusions: Most frequently, fissures result from CL/CLP with no familial history. However, CL/CLP was found in familial cases and cousins were the relative type more likely to be affected

The neural correlates of obsessive-compulsive disorder: a multimodal perspective

Obsessive-compulsive disorder (OCD) is one of the most debilitating psychiatric conditions. An extensive body of the literature has described some of the neurobiological mechanisms underlying the core manifestations of the disorder. Nevertheless, most reports have focused on individual modalities of structural/functional brain alterations, mainly through targeted approaches, thus possibly precluding the power of unbiased exploratory approaches. Eighty subjects (40 OCD and 40 healthy controls) participated in a multimodal magnetic resonance imaging (MRI) investigation, integrating structural and functional data. Voxel-based morphometry analysis was conducted to compare between-group volumetric differences. The whole-brain functional connectome, derived from resting-state functional connectivity (FC), was analyzed with the network-based statistic methodology. Results from structural and functional analysis were integrated in mediation models. OCD patients revealed volumetric reductions in the right superior temporal sulcus. Patients had significantly decreased FC in two distinct subnetworks: the first, involving the orbitofrontal cortex, temporal poles and the subgenual anterior cingulate cortex; the second, comprising the lingual and postcentral gyri. On the opposite, a network formed by connections between thalamic and occipital regions had significantly increased FC in patients. Integrative models revealed direct and indirect associations between volumetric alterations and FC networks. This study suggests that OCD patients display alterations in brain structure and FC, involving complex networks of brain regions. Furthermore, we provided evidence for direct and indirect associations between structural and functional alterations representing complex patterns of interactions between separate brain regions, which may be of upmost relevance for explaining the pathophysiology of the disorder