Multiscale Fractal Descriptors Applied to Nanoscale Images

This work proposes the application of fractal descriptors to the analysis of nanoscale materials under different experimental conditions. We obtain descriptors for images from the sample applying a multiscale transform to the calculation of fractal dimension of a surface map of such image. Particularly, we have used the}Bouligand-Minkowski fractal dimension. We applied these descriptors to discriminate between two titanium oxide films prepared under different experimental conditions. Results demonstrate the discrimination power of proposed descriptors in such kind of application

Characterization of nanostructured material images using fractal descriptors

This work presents a methodology to the morphology analysis and characterization of nanostructured material images acquired from FEG-SEM (Field Emission Gun-Scanning Electron Microscopy) technique. The metrics were extracted from the image texture (mathematical surface) by the volumetric fractal descriptors, a methodology based on the Bouligand-Minkowski fractal dimension, which considers the properties of the Minkowski dilation of the surface points. An experiment with galvanostatic anodic titanium oxide samples prepared in oxalyc acid solution using different conditions of applied current, oxalyc acid concentration and solution temperature was performed. The results demonstrate that the approach is capable of characterizing complex morphology characteristics such as those present in the anodic titanium oxide.Comment: 8 pages, 5 figures, accepted for publication Physica

Paleogene calcareous nannofossil biostratigraphic updates from equatorial Indian Ocean

Biostratigrafia e paleoceanografia di sedimenti provenienti dall'Oceano indiano equatorial

Magnetic properties of sedimentary greigite (Fe3S4): an update

Greigite (Fe3S4) is an authigenic ferrimagnetic mineral that grows as a precursor to pyrite during early diagenetic sedimentary sulfate reduction. It can also grow at any time when dissolved iron and sulfide are available during diagenesis. Greigite is important in paleomagnetic, environmental, biological, biogeochemical, tectonic, and industrial processes. Much recent progress has been made in understanding its magnetic properties. Greigite is an inverse spinel and a collinear ferrimagnet with antiferromagnetic coupling between iron in octahedral and tetrahedral sites. The crystallographic c-axis is the easy axis of magnetization, with magnetic properties dominated by magnetocrystalline anisotropy. Robust empirical estimates of the saturation magnetization, anisotropy constant, and exchange constant for greigite have been obtained recently for the first time, and the first robust estimate of the low-field magnetic susceptibility is reported here. The Curie temperature of greigite remains unknown, but must exceed 350°C. Greigite lacks a low-temperature magnetic transition. Based on preliminary micromagnetic modeling, the size range for stable single domain behavior is 17-200 nm for cubic crystals and 17-500 nm for octahedral crystals. Gradual variation in magnetic properties is observed through the pseudo-single domain size range. We systematically document the known magnetic properties of greigite (at high, ambient and low temperatures, and with alternating and direct fields) and illustrate how grain size variations affect magnetic properties. Recognition of this range of magnetic properties will aid identification and constrain interpretation of magnetic signals carried by greigite, which is increasingly proving to be environmentally important and responsible for complex paleomagnetic records, including widespread remagnetizations

IDIOPATHIC PARTIAL EPILEPSY WITH AUDITORY FEATURES (IPEAF): A CLINICAL AND GENETIC STUDY OF 53 SPORADIC CASES

The purpose of our study was to describe the clinical characteristics of sporadic (S) cases of partial epilepsy with auditory features (PEAF) and pinpoint clinical, prognostic and genetic differences with respect to previously reported familial (F) cases of autosomal dominant partial epilepsy with auditory features (ADPEAF). We analysed 53 patients (24 females and 29 males) with PEAF diagnosed according to the following criteria: partial epilepsy with auditory symptoms, negative family history for epilepsy and absence of cerebral lesions on NMR study. All patients underwent a full clinical, neuroradiological and neurophysiological examination. Forty patients were screened for mutations in LGI1/epitempin, which is involved in ADPEAF. Age at onset ranged from 6 to 39 years (average 19 years). Secondarily generalized seizures were the most common type of seizures at onset (79%). Auditory auras occurred either in isolation (53%) or associated with visual, psychic or aphasic symptoms. Low seizure frequency at onset and good drug responsiveness were common, with 51% of patients seizure-free. Seizures tended to recur after drug withdrawal. Clinically, no major differences were found between S and F patients with respect to age at onset, seizure frequency and response to therapy. Analysis of LGI1/epitempin exons failed to disclose mutations. Our data support the existence of a peculiar form of non-lesional temporal lobe epilepsy closely related to ADPEAF but without a positive family history. This syndrome, here named IPEAF, has a benign course in the majority of patients and could be diagnosed by the presence of auditory aura. Although LGI1 mutations have been excluded, genetic factors may play an aetiopathogenetic role in at least some of these S cases

Validity and reliability of self-report instruments for measuring physical activity in adolescents: a systematic review

Realizou-se revisão sistemática de estudos de reprodutibilidade e validade de instrumentos de medida da atividade física do tipo self-report - medidas subjetivas, em adolescentes (10-19 anos). Buscas foram realizadas em bases de dados (MEDLINE, PsycInfo, SportsDiscus, Scopus, Web of Science, SciELO, Lilacs) e nas referências dos artigos localizados. Sessenta e seis estudos atenderam aos critérios de inclusão. A maioria deles foi realizada em países da América do Norte, apenas cinco no Brasil. Identificaram-se 52 instrumentos diferentes: 42 questionários, 6 diários e 4 entrevistas. A reprodutibilidade "teste-reteste" variou de 0,20 a 0,98; a maioria (28/50) dos coeficientes apresentou valores < 0,70. Os coeficientes de validade apresentaram ampla variação (-0,13 a 0,88), sendo a maioria deles (64/84) < 0,50. Apenas três instrumentos apresentaram correlações &gt; 0,70. Diversos instrumentos foram testados em adolescentes, especialmente questionários. Em geral, tais instrumentos demonstraram melhor reprodutibilidade "teste-reteste" do que validade.This was a systematic review of studies on the reliability and validity of self-report instruments for measuring physical activity, or subjective measurements, in adolescents (10-18 years). Searches were conducted in databases (MEDLINE, PsycInfo, SportsDiscus, Scopus, Web of Science, SciELO, Lilacs) and in the references of the retrieved articles. Sixty-six studies met the inclusion criteria. The majority were from North America, with only 5 from Brazil. Fifty-two different instruments were identified: 42 questionnaires, 6 diaries or logs, and 4 interviews. "Test-retest" reliability varied from 0.20 to 0.98; the majority (28/50) of the coefficients showed values < 0.70. Validity coefficients showed wide variation (-0.13 to 0.88), with the majority (64/84) < 0.50. Only 3 instruments displayed correlations &gt; 0.70. Various instruments were tested in adolescents, especially questionnaires. These instruments generally showed better "test-retest" reliability than validity.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Tectonics and fluvial dynamism affecting the Tiber River in prehistoric Rome

Open access funding provided by Istituto Nazionale di Geofisica e Vulcanologia within the CRUI-CARE Agreement. Research funding was provided by Loeb Classical Library Foundation, Gerda Henkel Foundation, American Philosophical Society, Etruscan Foundation, Fondazione Lemmermann, University of Michigan, University of St Andrews, and the Leverhulme Trust.Geomorphological investigations in Rome’s river valley are revealing the dynamism of the prehistoric landscape. It is becoming increasingly apparent that paleogeographic conditions that defined Rome in the historical era are the product of changes since the Bronze Age, which may be the result of local fault activity in addition to fluvial dynamism. Through a dedicated borehole chronostratigraphic study, integrated by 14C and archaeological dates, and paleomagnetic investigations, we offer here new evidence for fault displacement since ca. 4500 years/BP. We present the failure of the sedimentary fabric of a clay horizon caused by liquefaction processes commonly linked with seismic shaking, interpreting an (ca. 4 m) offset to signify the existence of a fault line located at the foot of the Capitoline Hill. In addition, we show evidence for another (ca. 1 m) offset affecting a stratigraphic horizon in the river channel, occurring along another hypothesized fault line crossing through the Tiber Valley. Movement along this fault may have contributed to a documented phase of fast overflooding dated to the sixth century BCE which eventually led to the birth of the Tiber Island. The most plausible scenario implies progressive deformation, with an average tectonic rate of 2 mm/year, along these inferred fault lines. This process was likely punctuated with moderate earthquakes, but no large event necessarily occurred. Together, the available evidence suggests that during the early centuries of sedentary habitation at the site of Rome, active fault lines contributed to significant changes to the Tiber River valley, capable of challenging lowland activities.Publisher PDFPeer reviewe

Identifying plant species using architectural features of leaf microscopy images

This work proposes an analytical method to identify plant species based on microscopy images of the midrib cross-section of leaves. Unlike previous shape-based approaches based on the individual shape of external contours and cells, an architectural analysis is proposed, where the midrib is semi-automatically segmented and partitioned into histologically relevant structures composed of layers of cells and vascular structures. Using a sequence of morphological operations, a set of geometrical measures from the cells in each layer is extracted to produce a vector of features for species categorization. The method applied to a database containing 10 species of plants from the Brazilian flora achieved a success rate of 91.7%, outperforming other classical shape-based approaches published in the literature.Fil: Florindo, Joao Batista. Universidade de Sao Paulo; BrasilFil: Bruno, Odemir Martinez. Universidade de Sao Paulo; BrasilFil: Rossatto, Davi Rodrigo. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Kolb, Rosana Marta. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Gómez, María Cecilia. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Landini, Gabriel. University Of Birmingham; Reino Unid