3,186 research outputs found
Spatio-temporal conjecture for diffusion
We present here a conjecture about the equivalence between the noise density
of states of a system governed by a generalized Langevin equation and the
fluctuation in the energy density of states in a Hamiltonian system. We present
evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica
Genotypic and phenotypic differences between nosocomial and commensal Staphylococcus epidermidis isolates from northern Portugal
Staphylococcus epidermidis is a common causative agent of relapsing and persistent hospital-acquired infections, not only because this bacterium belongs to the patientsâ microbiota(causing autoinfection) but also because it is easily transmitted by healthcare workers (causing cross-infections). The goal of the present study was to characterize, for the first time, the biofilm-forming ability and virulence associated traits of several S. epidermidis strains circulating in a Portuguese hospital, as well as in the Portuguese community (northern region). To achieve that, bacteria were isolated from October 2011 to January 2013 and identified by biochemical tests and rpoB sequencing. Confirmed S. epidermidis strains were then tested for biofilm formation, antimicrobial resistance and carriage of biofilm-associated genes. The majority of clinical and skin isolates were resistant to erythromycin followed by penicillin. Regarding the presence of virulence-associated genes there was an equal distribution between the clinical and commensal isolates. The aap gene was the most prevalent (48% and 50%, respectively) followed by ica operon (37% and 33%, respectively) and bhp gene (15% and 17%, respectively). These results are in agreement with the ones obtained for the biofilm formation. Our results highlight slight differences between isolates obtained from the hospital setting and those obtained from the community. The emergence of antibiotic resistance and the frequent presence of virulence-associated genes among commensal Portuguese strains, reported in this study, raises serious clinical implications and should be considered to re-evaluate preventive measures against nosocomial infections
Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions
Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme ÏGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: LonnĂ©, MarĂa Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de QuĂmica; BrasilFil: Costa, PatrĂcia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, FĂ©lix A.. Universidade Federal de Santa Maria. Departamento de QuĂmica; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de LujĂĄn. Departamento de Ciencias BĂĄsicas; ArgentinaFil: Monserrat, JosĂ© MarĂa. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de CiĂȘncia e Tecnologia de Nanomateriais de Carbono; Brasi
A dynamic approach to teaching LSS at universities
Alongside the European Students of Industrial Engineering and Management (ESTIEM) a team of students from the University of Minho, in cooperation with a corporate partner, developed a free and scalable Lean Six Sigma (LSS) Green-Belt level course for Engineering students. Purpose: The authors aim to depict how free access to LSS Green-Belt knowledge before graduation can positively impact both engineering education and the students when in real-life projects. The purpose is not to build on existing literature, but to provide a practical teaching structure. Methodology: The authors chose to follow the hypothetico-deductive method which consists of formulating hypotheses and comparing them with real-life brought up from their personal experiences while teaching the course. Findings: This case study found a positive impact on both the students responsible for facilitating the training sessions, as well as the ones receiving practical and theoretical knowledge. With more than 60 course graduates, this model is generating positive results in growing awareness for LSS methods. Practical implications: This paper describes a practical application of a novel approach to teaching LSS in Universities along the obstacles surpassed to design it, blending it in the course curricula. It aims to foster similar implementations in other institutions. Originality: A teaching system built with students for students is scalable, low-cost, and highly engaging. Its deployment not only shows how it is possible to advance education by blending an existing LSS course structure but also how students can greatly benefit from a deeper LSS knowledge before their graduation.(undefined
Isothermal omega assisted alpha phase precipitation and microstructural evolution of an aged Ti-30Nb-3Fe alloy
The mechanical behavior of metastable ÎČ Ti alloys can be controlled through heat treatments. Thus, the relationship between the precipitation of α phase and the mechanical properties of these alloys is of special interest. In this work, the microstructure evolution of Ti-30Nb-3Fe alloy during aging heat treatments was evaluated using optical microscopy, scanning electron microscopy and X-ray diffraction. Moreover, Vickers hardness and elastic modulus were measured as a function of aging time. Finally, the ultimate strength and ductility of the alloy aged at 500 °C was assessed by tensile tests. In comparison to a Ti-30Nb alloy, the addition of Fe lowered the ÎČ-transus temperature, decreased the martensite start temperature to a value below room temperature, increased the precipitation temperature and reduced the dissolution temperature of Ï phase, and lastly, decreased the α phase precipitation temperature. Low heating rates enabled isothermal Ï phase precipitation and growth, providing favorable conditions for α phase precipitation and increasing the amount of α phase precipitates. Compared to the solution heat-treated and water-quenched condition, aging heat-treated Ti-30Nb-3Fe alloy presented higher Vickers hardness and mechanical strength, without significant loss of ductility233CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQCOORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP405054/2016-588887.357955/2019-002016/24693-3The authors gratefully acknowledge the LNNano (National Nanotechnology Laboratory) at the CNPEM (National Center for Research on Energy and Materials) for allowing access to its SEM facilities. We also acknowledge the financial support of the Brazilian research funding agencies FAPESP (State of SĂŁo Paulo Research Foundation) for Grant #2016/24693-3, CNPq (National Council for Scientific and Technological Development) for Grant #405054/2016-5, and CAPES/PNPD (Coordination for the Improvement of Higher Education Personnel) for Grant #88887.357955/2019-00. We thank the Brazilian Niobium Mining and Processing Company CBMM for supplying the Nb used in this stud
A compilation of experimental data on the mechanical properties and microstructural features of Ti-alloys
The present work depicts a compilation of mechanical properties of 282 distinct multicomponent Ti-based alloys and their respective microstructural features. The dataset includes the chemical composition (in at.%), phase constituents, Young modulus, hardness, yield strength, ultimate strength, and elongation. Each entry is associated with a high-quality experimental work containing a complete description of the processing route and testing setup. Furthermore, we incorporated flags to the dataset indicating (a) the use of high-resolution techniques for microstructural analysis and (b) the observation of non-linear elastic responses during mechanical testing. Oxygen content and average grain size are presented whenever available. The selected features can help material scientists to adjust the data to their needs concerning materials selection and discovery. Most alloys in the dataset were produced via an ingot metallurgy route, followed by solubilization and water quench (â58%), which is considered a standard condition for ÎČ-Ti alloys. The database is hosted and maintained up to date in an open platform. For completeness, a few graphical representations of the dataset are included.publishersversionpublishe
Atlantic mammal traits: a dataset of morphological traits of mammals in the atlantic forest of south America
Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species, but also within species. Mammals are an interesting group for investigating trait-based approaches because they play diverse and important ecological functions (e.g., pollination, seed dispersal, predation, grazing) that are correlated with functional traits. Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from â5.83 to â29.75 decimal degrees of latitude and â34.82 to â56.73 decimal degrees of longitude in the Atlantic forest of South America. We present trait information from 16,840 individuals of 181 species of non-volant mammals (Rodentia, Didelphimorphia, Carnivora, Primates, Cingulata, Artiodactyla, Pilosa, Lagomorpha, Perissodactyla) and from 23,010 individuals of 98 species of volant mammals (Chiroptera). The traits reported include body mass, age, sex, reproductive stage, as well as the geographic coordinates of sampling for all taxa. Moreover, we gathered information on forearm length for bats and body length and tail length for rodents and marsupials. No copyright restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.Fil: Gonçalves, Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Bovendorp, Ricardo S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Beca, Gabrielle. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Bello, Carolina. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Costa Pereira, Raul. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Muylaert, Renata L.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rodarte, Raisa R.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Villar, Nacho. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Souza, Rafael. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Graipel, MaurĂcio E.. Universidade Federal de Santa Catarina; BrasilFil: Cherem, Jorge J.. Caipora Cooperativa, Florianopolis; BrasilFil: Faria, Deborah. Universidade Estadual de Santa Cruz; BrasilFil: Baumgarten, Julio. Universidade Estadual de Santa Cruz; BrasilFil: Alvarez, MartĂn R.. Universidade Estadual de Santa Cruz; BrasilFil: Vieira, Emerson M.. Universidade do BrasĂlia; BrasilFil: CĂĄceres, Nilton. Universidade Federal de Santa MarĂa. Santa MarĂa; BrasilFil: Pardini, Renata. Universidade de Sao Paulo; BrasilFil: Leite, Yuri L. R.. Universidade Federal do EspĂrito Santo; BrasilFil: Costa, Leonora Pires. Universidade Federal do EspĂrito Santo; BrasilFil: Mello, Marco Aurelio Ribeiro. Universidade Federal de Minas Gerais; BrasilFil: Fischer, Erich. Universidade Federal do Mato Grosso do Sul; BrasilFil: Passos, Fernando C.. Universidade Federal do ParanĂĄ; BrasilFil: Varzinczak, Luiz H.. Universidade Federal do ParanĂĄ; BrasilFil: Prevedello, Jayme A.. Universidade do Estado de Rio do Janeiro; BrasilFil: Cruz-Neto, Ariovaldo P.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Carvalho, Fernando. Universidade do Extremo Sul Catarinense; BrasilFil: Reis Percequillo, Alexandre. Universidade de Sao Paulo; BrasilFil: Paviolo, Agustin Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș; ArgentinaFil: Duarte, JosĂ© M. B.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil. FundaciĂłn Oswaldo Cruz; BrasilFil: Bernard, Enrico. Universidade Federal de Pernambuco; BrasilFil: Agostini, Ilaria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș; ArgentinaFil: Lamattina, Daniela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentina. Ministerio de Salud de la NaciĂłn; ArgentinaFil: Vanderhoeven, Ezequiel Andres. Ministerio de Salud de la NaciĂłn; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentin
Acoustics reflex abnormalities in auditory processing disorder
Introduction: The acoustic reflex threshold is defined as the lowest sound intensity capable of starting the middle ear protection mechanism due to intense sounds (Metz, 1952; Jerger, 1970), being necessary the structural and functional integrity of the periferic and central auditory system. These structures are also responsable for the central processing of auditory information. Aim: We intend to verify whether acoustic reflex abnormalities can also appear in auditory processing (AP) disorders, resulting in symptoms related to speech and language disorders. Study design: Prospective randomized. Material and method: Data were analyzed from one hundred AP assessments, using Pereira (1997) method. Patients, male and female, with ages ranging from 07 to 18 years, had normal hearing thresholds and normal tympanograms patterns. The difference between the acoustic reflex and hearing thresholds defined the acoustic reflex level (ARL), considered normal between 70-90dB and altered when above of this range or when absent in one or more frequencies (Carvallo, 1996; 1997; Metz, 1952). Results: Disorders of AP were found in 97% of the patients. In this group, 62% showed ARL abnormalities, being statistically significant. Furthermore, patients with AP disorders showed ARL alterations, more frequently on severe degree disorders, on patients with combined auditory gnosis impairments and on patients with more than one auditory ability altered. Conclusion: Patients with acoustic reflex alterations and normal audiometry should perform the AP assessment, as these symptoms could unmask pathologies of the central nervous system.Introdução: O limiar do reflexo acĂșstico corresponde Ă menor intensidade de um som capaz de desencadear o mecanismo de proteção da orelha mĂ©dia frente a sons intensos (Metz, 1952; Jerger, 1970), sendo necessĂĄria a integridade estrutural e funcional do sistema auditivo perifĂ©rico e central em nĂvel de tronco encefĂĄlico. Algumas dessas estruturas sĂŁo tambĂ©m responsĂĄveis pelo processamento central da informação auditiva. Objetivo: Procuramos verificar se alteraçÔes do reflexo acĂșstico tambĂ©m estariam presentes na Desordem do Processamento Auditivo Central (DPA), levando a queixas relacionadas aos distĂșrbios da comunicação. Forma de estudo: Prospectivo randomizado. Material e mĂ©todo: Foram analisados cem protocolos de avaliaçÔes do Processamento Auditivo Central (PAC), realizadas segundo Pereira (1997), de indivĂduos dos sexos masculino e feminino, de 7 a 18 anos, com limiares de audibilidade normais e timpanograma tipo A. A diferença entre os limiares do reflexo acĂșstico e os de audibilidade forneceu os nĂveis de reflexos acĂșsticos (NRA), considerados normais entre 70-90dB e alterados quando acima deste intervalo ou quando ocorreu ausĂȘncia em uma ou mais freqĂŒĂȘncias (Carvallo, 1996; 1997; Metz, 1952). Resultados: Das crianças avaliadas 97% apresentaram algum tipo de DPA. Destas, 62% tiveram NRA alterados, numa relação estatisticamente significante. AlĂ©m disso, pacientes com DPA mostraram NRA alterados, mais freqĂŒentemente, nas desordens de grau severo, naquelas com prejuĂzos gnĂłsicos auditivos combinados e naquelas com mais de uma habilidade auditiva alterada. ConclusĂŁo: Assim, indivĂduos com alteraçÔes no reflexo acĂșstico e sem alteraçÔes audiomĂ©tricas devem submeter-se a provas de PAC, jĂĄ que esses sintomas podem ser manifestaçÔes patolĂłgicas do sistema nervoso central.UNIFESP-EPM OtorrinolaringologiaUNIFESP-EPMUNIFESP, EPM, OtorrinolaringologiaUNIFESP, EPMSciEL
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Effectiveness of Insecticide Spraying and Culling of Dogs on the Incidence of Leishmania infantum Infection in Humans: A Cluster Randomized Trial in Teresina, Brazil
Background: To evaluate the effect of insecticide spraying for vector control and elimination of infected dogs on the incidence of human infection with L. infantum, a randomized community intervention trial was carried out in the city of Teresina, Brazil. Methods/Principal Findings Within each of ten localities in the city, four blocks were selected and randomized to 4 interventions: 1) spraying houses and animal pens with insecticide; 2) eliminating infected dogs; 3) combination of spraying and eliminating dogs, and 4) nothing. The main outcome is the incidence of infection assessed by the conversion of the Montenegro skin test (MST) after 18 months of follow-up in residents aged â„1 year with no previous history of visceral leishmaniasis (VL). Reactions were measured at 48â72 h, induration of â„5 mm considered positive. Interventions were executed after the baseline interview and repeated 6 and 12 months later. The effects of each type of intervention scheme on the incidence of infection were assessed by calculating relative risks and 95% confidence intervals using Poisson population-averaged regression models with robust variance. Among the 1105 participants, 408 (37%) were MST positive at baseline. Of the 697 negatives, only 423 (61%) were reexamined at the end of the follow-up; 151 (36%) of them converted to a positive MST. Only dog culling had some statistically significant effect on reducing the incidence of infection, with estimates of effectiveness varying between 27% and 52%, depending on the type of analysis performed. Conclusions/Significance: In light of the continuous spread of VL in Brazil despite the large scale deployment of insecticide spraying and dog culling, the relatively low to moderate effectiveness of dog culling and the non-significant effect of insecticide spraying on the incidence of human infection, we conclude that there is an urgent need for revision of the Brazilian VL control program
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