Universidade Federal Fluminense
  • Niterói, Rio de Janeiro, Brazil
Recent publications
In this chapter, the question of how to integrate the software component with the rest of the product is answered through a simple implementation method. A technique that facilitates fast tracking of hardware and software development activities is also presented.
This chapter presents the process for the Design of Innovative Products (DIP), starting with its rationale and other considerations and techniques that comprise its cognitive foundation. DIP smoothly integrates the three previously summarized product design methodologies plus the management of the knowledge assets that are created during the product design process.
This chapter is dedicated to introducing the design methodologies used as a basis for the process presented in this book, as well as introducing the techniques related to the management of intellectual assets.
This work presents the strategies used in the development of the teaching of the subject of Architecture Project III of the School of Architecture and Urbanism of the Federal Fluminense University from the return to classes during the period of the Covid-19 Coronavirus pandemic which started in 2020. The course was carried out in the online teaching system mediated by technology. Considering the complexity that the teaching of architecture design requires in the fourth semester of the course, and given the conditions imposed by the pandemic, the development of technology-mediated design teaching was a challenge faced by the teachers of the subject. The teaching project theme is complex and extensive and considers a mixed-use high-rise building, with residential and commercial units in a consolidated urban environment, oriented towards the design and development of open and closed spaces, as well as public, collective and private spaces. This article covers the experiences, the strategies adopted, the difficulties and the results obtained in the teaching of architectural design from September 2020 until February 10, 2022.
The intention of this work is to show a simple and efficient way to compute the deforestation area using Landsat 8 satellite images. It considers only its best band and segmentation based on thresholding. The described approach is simple to be used in public available images of this type (http://www.dgi.inpe.br/catalogo/), can be easy implemented in any computed language or downloaded in this public repository: https://github.com/rmparanhos/analise-imagens. Maybe the most complex aspect on processing this type of imaging is due to the great numbers of pixels and band (or channel) that compose each mosaic and each real area to be studied. The presented material can be useful due the difficulty of finding benchmarks to allow comparison among results.
In this paper we introduce the notion of lk-convexity, a natural restriction of the monophonic convexity. Let G be a graph and k≥2 an integer. A subset S⊆V(G) is lk-convex if and only if for any pair of vertices x,y of S, each induced path of length at most k connecting x and y is completely contained in the subgraph induced by S. The lk-convexity consists of all lk-convex subsets of G. In this work, we characterize lk-convex geometries (graphs that are convex geometries with respect to the lk-convexity) for k∈{2,3}. We show that a graph G is an l2-convex geometry if and only if G is a chordal P4-free graph, and an l3-convex geometry if and only if G is a chordal graph with diameter at most three such that its induced gems satisfy a special “solving” property. As far as the authors know, the class of l3-convex geometries is the first example of a non-hereditary class of convex geometries.
Objective: To examine the relationships between sociodemographic characteristics, student academic information, social support, sense of coherence, anxiety, lifestyle, and quality of life among dental students. Methods: A cross-sectional study among 233 dental students in Brazil. We captured data on sociodemographic and socioeconomic characteristics, social support through Social Support Appraisal, psychosocial factors (sense of coherence and anxiety based on SOC-13 and Depression, Anxiety and Stress Scale-21 - anxiety subscale, respectively), lifestyle as per individual Lifestyle Profile and quality of life based on VERAS-Q. Data was analysed through Structural Equation Modelling. Results: Greater social support, higher sense of coherence, lower anxiety, better lifestyle directly predicted better quality of life. Male gender, city of origin did not differ from the city of the campus, higher social support and greater sense of coherence were indirectly linked with better quality of life via better lifestyle. Lower academic semester and higher social support indirectly predicted better quality of life via lower anxiety. Conclusion: Social support, sense of coherence, anxiety, and lifestyle were relevant factors directly associated with dental student's quality of life. Indirect pathways were observed between gender, moved home to attend dental course, academic semester, social support, sense of coherence, and quality of life.
Background Birdshot retinochoroiditis (BRC) is a rare and chronic bilateral uveitis mostly found in Caucasians. As few data are available about the clinical course of BRC in Hispanic patients, we aimed to report the clinical findings and the evolution of BRC in Brazilian patients. Methods This retrospective cohort multicenter nationwide study was performed by analyzing the records of patients with BRC diagnoses from Brazilian ophthalmological centers from April 1995 to May 2020. Results Forty patients (80 eyes) with a diagnosis of BRC were evaluated. The mean age was 53 years, and there was no sex predominance. All tested patients (34/40) were positive for HLA-A29. The diagnosis of BRC was made following the Levinson et al. criteria, and all ancillary tests were performed to exclude differential diagnoses. Clinical signs and symptoms, such as complications and treatment, were described. Conclusions BRC evolution in Brazilian patients seems to have some peculiarities that diverge from the published literature available about Caucasians, as AS inflammation is higher in this population.
Objective To provide guidelines on the coronavirus disease 2019 (COVID-19) vaccination in patients with immune-mediated rheumatic diseases (IMRD) to rheumatologists considering specific scenarios of the daily practice based on the shared-making decision (SMD) process. Methods A task force was constituted by 24 rheumatologists (panel members), with clinical and research expertise in immunizations and infectious diseases in immunocompromised patients, endorsed by the Brazilian Society of Rheumatology (BSR), to develop guidelines for COVID-19 vaccination in patients with IMRD. A consensus was built through the Delphi method and involved four rounds of anonymous voting, where five options were used to determine the level of agreement (LOA), based on the Likert Scale: (1) strongly disagree; (2) disagree, (3) neither agree nor disagree (neutral); (4) agree; and (5) strongly agree. Nineteen questions were addressed and discussed via teleconference to formulate the answers. In order to identify the relevant data on COVID-19 vaccines, a search with standardized descriptors and synonyms was performed on September 10th, 2021, of the MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and LILACS to identify studies of interest. We used the Newcastle–Ottawa Scale to assess the quality of nonrandomized studies. Results All the nineteen questions-answers (Q&A) were approved by the BSR Task Force with more than 80% of panelists voting options 4—agree—and 5—strongly agree—, and a consensus was reached. These Guidelines were focused in SMD on the most appropriate timing for IMRD patients to get vaccinated to reach the adequate covid-19 vaccination response. Conclusion These guidelines were developed by a BSR Task Force with a high LOA among panelists, based on the literature review of published studies and expert opinion for COVID-19 vaccination in IMRD patients. Noteworthy, in the pandemic period, up to the time of the review and the consensus process for this document, high-quality evidence was scarce. Thus, it is not a substitute for clinical judgment.
We performed a cross-sectional study in 212 PLHIV under antiretroviral therapy. Bone mass was compromised in 36.5% of relatively young sample and associated with hypogonadism, older age, higher PTH levels, and metabolic syndrome. Hypovitaminosis D was present in 85%, especially those on NNRTI. Purpose: Previous studies have reported an increased prevalence of bone demineralization among people living with the human immunodeficiency virus (PLHIV). We aimed to assess bone mineral density (BMD), vitamin D levels, and associated risk factors in Brazilian PLHIV. Methods: Cross-sectional study with 212 patients in a specialized assistance service. Clinical and demographic information were registered. Laboratory tests were performed, and BMD was measured at the lumbar spine, total hip/femoral neck, and forearm by dual-energy X-ray absorptiometry. Participants were classified into "with low bone mass (wLBM)" and "without low bone mass (woLBM)." Those wLBM encompasses osteoporosis, osteopenia, and below the expected range for age as recommended by the World Health Organization. Results: One hundred and eighty-seven patients were included. Median age was 46.3 years (interquartile range (IQR) 40-52) and duration of HAART exposure was 11.2 years (IQR 7-15). Plasma viral load was undetectable in 79%. Hypovitaminosis D (< 30 ng/mL) was present in 85% and LBM in 36.5%. Men wLBM were more likely to have testosterone deficiency and had higher PTH levels than those woLBM. LBM in women was associated with older age, menopause, and metabolic syndrome. Conclusion: This study showed a high frequency of LBM in a relatively young sample, and suggests a detrimental effect of hypogonadism, older age, higher PTH levels, and metabolic syndrome. Hypovitaminosis D was frequent, especially those on non-nucleoside reverse transcriptase inhibitor, higher body mass index, and abdominal circumference.
Purpose To evaluate the impact of a paediatric radiological protection campaign, implemented in the emergency units of a healthcare provider network in Brazil. This campaign aimed to promote awareness among emergency department physicians, regarding justification of paediatric X-ray referrals for paranasal sinus, chest and CT exams, as a strategy to reduce exposure to ionising radiation. Method Frequency analysis of common paediatric imaging referrals from 19 emergency departments was performed for a 3-year period (2015–2018) to coincide with before, during and after the implementation of the radiation protection campaign. The campaign was multifaceted and involved dissemination of educational materials and imaging referral guidelines along with quarterly meetings with participating centres' leaderships. Additionally, patient dose cards were distributed to patients/carers. The Chi-Square test was used to examine the association between the type of examination and the patient's age group. Exact-Fisher test was performed to check for an association between participant engagement and the existence of the radiation protection committee. Results Referrals reduced by 25% following the campaign with no reports of misdiagnosis. Many referrals in the youngest age groups. In 15 units, a radiological protection committee was created to raise awareness and to create a multi professional team to communicate the risks and benefits of radiological procedure in children. Conclusion The campaign resulted in a substantial reduction in radiological referrals while promoting a radiation protection culture. Simple education initiatives can contribute to savings in both finances and radiation doses, particularly important in radiosensitive cohorts.
The Muaco and Taima-Taima sites, in Falcón State of northwestern Venezuela, are among the earliest sites of human occupation in South America containing artifacts associated with preserved megafaunal remains and dating between 19,810 and 15,780 calybp. Here we report novel visual and CT scanning analysis of six glyptodont skulls of Glyptotherium cf. cylindricum from these sites, of which four exhibit distinct and similar patterns of breakages in the fronto-parietal region that suggest intentional blows by direct percussion by humans, with fractures not being diagenetic but instead antemortem or transmortem. This hypothesized and unreported hunting technique focused in an area of the skull where the cephalic shield becomes thin, thus increasing the effectiveness of the blow. From Taima-Taima other glyptodont remains included an inverted carapace, also previously reported as probable evidence of human–glyptodont interaction during the latest Pleistocene. We estimated that roughly 150-170 Kg of potentially accessible muscles and fat of an adult Glyptotherium cylindricum could be used as food sources.
Loneliness has emerged as a public health concern. Previous research has reported its deleterious effects on physical and mental health; however, some specific psychophysiological mechanisms in healthy adults remain to be elucidated. The aim of the current study is to investigate whether self-reported social support and social touch (giving and receiving social touch), as well as resting heart rate variability (HRV), are significant negative predictors of loneliness in healthy adults. The study sample consists of 120 healthy students (50% female) with a mean age of 21.85 years old (DP= 2.21). The students were asked to complete a psychiatric screening questionnaire utilizing loneliness, social support, and social touch scales. HRV was derived from an electrocardiographic signal recorded for 15 min, with the participant relaxed in a supine position. Linear regression analyses were conducted to evaluate loneliness as a function of social support, social touch (giving or receiving touch), and resting HRV. The results show that social support ( p < 0.001) and social touch, specifically receiving touch ( p < 0.002), accounted for a significant proportion of the variance in loneliness. However, neither giving touch nor resting HRV was a significant predictor of loneliness. The current study highlights specific psychosocial factors in healthy adults that should be considered as promising pathways in order to reduce or work toward preventing loneliness, thus promoting better health and well-being.
We study the Yamabe equation in the Euclidean half-space. We prove that any sign-changing solution has at least twice the energy of a standard bubble. Moreover, a sharper energy lower bound of the sign-changing solution set is also established via the method of moving planes. This bound increases the energy range for which Palais–Smale sequences of related variational problem has a non-trivial weak limit.
Electric power systems influences on nearby structures have been widely investigated in the last decades. Generally, the practical projects contemplate simplified studies that calculate just part of the system. The literature is vague regarding whether this standard procedure may cause a difference in the calculated results. This paper investigates inductive and conductive influences along a buried pipeline from an overhead transmission line during normal load operation and fault conditions. Two situations are compared: only part of the pipeline stretch near the interfering system and its total length. A case study investigates the influences from an overhead transmission line on a buried pipeline for parallelism and crossing approaches by proposing an accessible methodology, whose results are compared with commercial programs widely used by design engineers and with good accuracy. The main focus of this work is to show that the most common practice of considering only the region where an overhead line is closest to the pipeline may lead to underestimating the induced voltage. Instead, to correctly assess pipeline-induced voltage, one may need to represent in detail the whole pipeline. High deviations indicate that a pipeline may suffer corrosion and put personal safety at risk if mitigation measures are not implemented. Computations considering the whole pipeline path are essential for structural and personal integrity. Besides, the proposed accessible methodology is useful, given alternatives to the few commercially available software.
Morphological, morphometric, and chemical analysis of otoliths have proven to be useful tools for intraspecific comparison and identification of fish stocks. In the present study, we used otolith silhouette and morphometric analysis (n = 103) in addition to chemical signatures (n = 20) to test the hypothesis of a single stock unit of skipjack tuna (Katsuwonus pelamis) in the Southwest Atlantic Ocean (20–34°S). No significant differences were found between sexes (t-test p > 0.05), enabling analyses for all study specimens to be grouped. Cluster analysis using Fourier coefficients (30 first harmonics) differentiated three otolith morphotypes within South (28–34°S) and Southeast (20–28°S) regions of the study area. Harmonic principal component analysis using the first two significant axes showed no pattern of spatial separation by region. Among the seven shape descriptors examined, only circularity and form factor showed significant differences between the morphotypes (A and B). Microchemistry analysis (LA/ICP-MS) applied to the core portion of fish otoliths showed significant differences in Ba, Mn and Mg concentrations between the two regions and morphotypes (p < 0.05). These results support that the Katsuwonus pelamis population in the Southwest Atlantic Ocean belong to a single stock unit with a probable common area of origin. Specimens captured in the South and Southeast regions of Brazil had heterogeneous phenotypic attributes regarding otolith shape, probably determined by a temporal equilibrium selection process.
Given a finite, simple, and undirected graph G=(V,E), a P3-convex set of G is a set S⊆V(G) such that every vertex of V(G)∖S has at most one neighbor in S, and the P3-convex hull of a vertex subset S′ of G is the smallest P3-convex set containing S′. The P3-hull number h(G) is the cardinality of the smallest set of vertices whose P3-convex hull is V(G). In this paper, we establish some bounds on the P3-hull number of graphs with diameter two. Particularly, for a biconnected diameter-two graph G it holds that h(G)≤⌈log(Δ(G)+1)⌉+1, while a non-biconnected diameter-two graph G has h(G)=cc(G−v), where v is a cut vertex of G and cc(G−v) is the number of connected components of G[V∖{v}]. In addition, we show that the P3-hull number of biconnected C6-free diameter-two graphs is at most 4, while for strongly regular graphs G=G(n,k,b,c) it holds that h(G)≤min{⌈k1+b⌉+1,⌈logc+1(k.c+1)⌉+1}. Finally, we consider the P3-interval number, which is the cardinality of the smallest set S of vertices such that every vertex not in S has two neighbors in this set. We show that computing the P3-interval number on diameter-two split graphs is NP - complete.
This work presents the starting of a trapped flux superconducting motor considering two drive methods: direct starting (using an AC power source) and soft starting (using a frequency inverter). These two methods present different characteristics that are expected to affect the behavior of the superconducting motor. For the direct starting, there is inrush current but no harmonics. On the contrary, for soft starting, there are harmonics but no inrush current. To understand the impacts of the starting current or the harmonics on the performance of superconducting motors, different tests were carried out on a superconducting motor prototype under the aforementioned drive methods. This prototype, using commercial Rare-Earth Barium Copper Oxide (REBCO) tapes, was first connected to a frequency inverter (harmonics tests), and then to an AC power source (starting current tests) and tested at 77 K in liquid nitrogen. The torque under load variations, the mechanical power, the losses, and the harmonics content of the machine were assessed. Key results showed that the motor losses increase due to a high content of harmonics during the soft starting. Consequently, the torque and the mechanical power decreased significantly compared to the direct starting. Nevertheless, the latter may present some risks for the physical integrity of the rotor as a large transient current can flow in the winding accompanied by higher mechanical stresses. For industrial motors of more outstanding power ratings with a wide range of applications requiring one or the other starting methods, it is necessary to further mature the design with machines of increasing rated power if such devices ought to be used reliably in the industry (in the kW range and above).
We study Birkhoff averages along trajectories of smooth reparameterizations of irrational linear flows of the two torus with two stopping points, say p and q, of quadratic order. The limiting behaviour of such averages is independent of the starting point in a set of full Haar-Lebesgue measure and depends in an intricate way on the Diophantine properties of both the slope α of the linear flow as well as the relative position of p and q. In particular, if α is Diophantine, then Birkhoff limits diverge almost everywhere (historic behaviour) and if α is sufficiently Liouville, then there exists some p and q such that the Birkhoff averages converge almost everywhere (unique physical measure).
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13,137 members
Monica Diuana Calasans-Maia
  • Faculdade de Odontologia
Helder Gomes Costa
  • Departamento de Engenharia de Produção (TEP)
Marcio Zamboti Fortes
  • Departamento de Engenharia Elétrica (TEE)
Gabriel Martins
  • Departamento de Microbiologia e Parasitologia (MIP)
Rua Miguel de Frias, 9 , 24020-091, Niterói, Rio de Janeiro, Brazil
Head of institution
Prof. Antonio Claudio Lucas da Nóbrega