Image Segmentation by Image Foresting Transform with Non-smooth Connectivity Functions

Abstract-Image segmentation, such as to extract an object from a background, is very useful for medical and biological image analysis. In this work, we propose new methods for interactive segmentation of multidimensional images, based on the Image Foresting Transform (IFT), by exploiting for the first time non-smooth connectivity functions (NSCF) with a strong theoretical background. The new algorithms provide global optimum solutions according to an energy function of graph cut, subject to high-level boundary constraints (polarity and shape), or consist in a sequence of paths' optimization in residual graphs. Our experimental results indicate substantial improvements in accuracy in relation to other state-of-the-art methods, by allowing the customization of the segmentation to a given target object

Straightforward synthesis of isoellipticine by palladium‐catalysed coupling reactions

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOOur novel synthetic route to isoellipticine featured palladium‐catalyzed intramolecular reactions for the construction of the B ring of the pyridocarbazole nucleus. The adequate palladium‐catalyzed reaction depended upon the oxidation conditions that were32436439FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO14/25770‐6SEM INFORMAÇÃOSEM INFORMAÇÃOThis work was supported by a grant from the State of São Paulo Research Foundation, FAPESP (grant number 14/25770‐6). The Chemistry Institute of UNICAMP is deeply acknowledged for the provided analytical facilities. J. A. M. C., F. F. N. and B. K. S. tha

Image Segmentation by Image Foresting Transform with Non-smooth Connectivity Functions

Abstract-In the framework of the Image Foresting Transform (IFT), there is a class of connectivity functions that were vaguely explored, which corresponds to the non-smooth connectivity functions (NSCF). These functions are more adaptive to cope with the problems of field inhomogeneity, which are common in MR images of 3 Tesla. In this work, we investigate the NSCF from the standpoint of theoretical and experimental aspects. We formally classify several non-smooth functions according to a proposed diagram representation. Then, we investigate some theoretical properties for some specific regions of the diagram. Our analysis reveals that many NSCFs are, in fact, the result of a sequence of optimizations, each of them involving a maximal set of elements, in a well-structured way. Our experimental results indicate that substantial improvements can be obtained by NSCFs in the 3D segmentation of MR images of 3 Tesla, when compared to smooth connectivity functions

Influence of micro-textures on cutting insert heat dissipation

Metal machining is one of the most important manufacturing processes in today’s production sector. The tools used in machining have been developed over the years to improve their performance, by reducing the cutting forces, the friction coefficient, and the heat generated during the cutting process. Several cooling systems have emerged as an effective way to remove the excessive heat generated from the chip-tool contact region. In recent years, the introduction of nano and micro-textures on the surface of tools has allowed to further improve their overall performance. However, there is not sufficient scientific data to clearly show how surface texturing can contribute to the reduction of tool temperature and identify its mechanisms. Therefore, this work proposes an experimental setup to study the tool surface characteristics’ impact on the heat transfer rate from the tools’ surface to the cooling fluid. Firstly, a numerical model is developed to mimic the heat energy flow from the tool. Next, the design variables were adjusted to get a linear system response and to achieve a fast steady-state thermal condition. Finally, the experimental device was implemented based on the optimized numerical model. A good agreement was obtained between the experimental tests and numerical simulations, validating the concept and the implementation of the experimental setup. A square grid pattern of 100 μm × 100 μm with grooves depths of 50, 100, and 150 μm was introduced on cutting insert surfaces by laser ablation. The experimental results show that there is a linear increase in heat transfer rate with the depth of the grooves relatively to a standard surface, with an increase of 3.77% for the depth of 150 μm. This is associated with the increase of the contact area with the coolant, the generation of greater fluid turbulence near the surface, and the enhancement of the surface wettability.This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant 2020.07155.BD and by the project POCI-01-0145-FEDER-030353 (SMARTCUT). Additionally, this work was supported by FCT national funds, under the national support to R&D units grant, through the reference projects UIDB/04436/2020 and UIDP/04436/2020

Hippocampal Astrocytes in Migrating and Wintering Semipalmated Sandpiper

Seasonal migratory birds return to the same breeding and wintering grounds year after year, and migratory long-distance shorebirds are good examples of this. These tasks require learning and long-term spatial memory abilities that are integrated into a navigational system for repeatedly locating breeding, wintering, and stopover sites. Previous investigations focused on the neurobiological basis of hippocampal plasticity and numerical estimates of hippocampal neurogenesis in birds but only a few studies investigated potential contributions of glial cells to hippocampal-dependent tasks related to migration. Here we hypothesized that the astrocytes of migrating and wintering birds may exhibit significant morphological and numerical differences connected to the long-distance flight. We used as a model the semipalmated sandpipe

Investigating the seismic response of URM walls with irregular opening layout through different modeling approaches

TThe façade and internal walls of unreinforced masonry (URM) buildings often present an irregular opening layout, due to architectural reasons or modifications to the structure, which make the expected seismic damage pattern less predictable a priori. Therefore, the discretization of the walls in structural components is not standardized, conversely to cases with a regular opening layout for which the available modeling methods are corroborated by seismic damage surveys reporting recurrent failure patterns. The structural component discretization is a relevant step for the code-conforming seismic assessment, typically based on comparing the internal forces and drifts of each component to strength criteria and drift thresholds. Therefore, the lack of well-established approaches can significantly influence the assessment. The issue is even more evident when the structural components must be identified a priori in the modeling stage, namely for equivalent frame models. The applicability of available methods for discretization of URM walls with irregular opening layout has been already investigated in literature, but a conclusive judgment requires further studies. In this context, this paper presents an overview of the preliminary results addressing the numerical modeling of this type of walls within the framework of the DPC-ReLUIS 2022-2024 project (Subtask 10.3), funded by the Italian Department of Civil Protection. The Subtask aims to propose consensus-based recommendations for researchers and practitioners which can contribute to harmonize the use of different modeling approaches. Seven research groups are involved in the research, adopting different modeling approaches and computer codes, but similar assumptions and the same analysis method (pushover) are used. The benchmark URM structure illustrated in the paper is a two-story wall from which four configurations with increasing irregularity of opening layout were derived. The results of four modeling approached are presented. Three of them reproduce the mechanical response of masonry at the material scale by means of FE models implemented in OpenSees, DIANA and Abaqus software, while the remaining approach describes the mechanical response of masonry at the macro-element scale in 3DMacro software. Results were compared in terms of capacity curves, predicted failure mechanisms and evolution of internal forces in piers. The adoption of consistent assumptions among the different approaches led to an overall agreement of predictions at both wall and pier scales, particularly in terms of damage pattern with higher concentration of damage at the ground story. Despite that, differences on the pushover curves have been highlighted. They are mainly due to some deviations of the internal forces in squat piers deriving from a complex load flow in these elements.DPC - Dipartimento della Protezione Civile, Presidenza del Consiglio dei Ministri(LA/P/0112/2020

The ITRAX core scanner, a useful tool to distinguish anthropic vs. climatic influences in lagoon of Aveiro (N Portugal)

The main goal of this work is to distinguish anthropic and climatic influences in sediments from the lagoon of Aveiro (Portugal). This study is based on a core (240-cm long) collected in Murtosa Channel. Optical and X-radiographic images and high-resolution elemental profiles were acquired with ITRAX micro-X-ray fluorescence (XRF) core scanner. Samples collected at each ≈3 cm along the core were analysed for grain size and total organic carbon. Furthermore, the fine fraction of selected layers was subjected to geochemical analysis by ICP-MS, after total acid digestion of the sediments, and mineralogical analysis, by XRD techniques. A radiocarbon age was determined by AMS, using molluscs shells collected at a depth of 90 cm. Sediments along the core are composed by fine and medium sand, with several mud layers. Sediments composing the first 100-cm may have been deposited after 1950, as it is indicated by the radiocarbon data, the increasing trend of Zn/Al, Pb/Al and Cu/Al and total concentrations of Zn, Pb, Cu, V, Cr, As and Ni in this interval that therefore might be linked with industrial activities of Chemical Complex of Estarreja. The progressive increase of Si/Al, Cl/Al, Rb/Al, K/Al and Br/Al and reduced Al concentrations, from the base to the top of this core, are interpreted as being related to higher marine influence and greater differences in tidal currents with longer exposition to air of the sediments with the consequent formation of brines favouring minerals precipitation in the area (e.g. anhydrite). These results seem to be a consequence of several works developed over time like: i) dredging to improve the navigation access to the harbour, located in the external sector of the lagoon; ii) the control of the course of some rivers influencing the supply of sediments. The tendency of sea level rise may have also emphasized the gradual increase of marine influence in this area. Fine-grained sections, related to an increase in Al, phyllosilicates, organic matter, pyrite and siderite contents would be attributed to phases of greater supply of fine-sediments during heavy rainfall events by the nearby Antuã river and other streams during negative phases of North Atlantic Oscillation. Higher deposition of organic matter enhanced diagenetic changes with pyrite and siderite formation. In the bottom of the core another record of pollution was unveiled to mining activities at the beginning of 20th century.FCT de Portugal - C/CTE/UI4035/2011CNPq - 401803/2010-

Development of a Cyclic Voltammetry-Based Method for the Detection of Antigens and Antibodies as a Novel Strategy for Syphilis Diagnosis

54/2017). Publisher Copyright: © 2022 by the authors.The improvement of laboratory diagnosis is a critical step for the reduction of syphilis cases around the world. In this paper, we present the development of an impedance-based method for detecting T. pallidum antigens and antibodies as an auxiliary tool for syphilis laboratory diagnosis. We evaluate the voltammetric signal obtained after incubation in carbon or gold nanoparticle-modified carbon electrodes in the presence or absence of Poly-L-Lysine. Our results indicate that the signal obtained from the electrodes was sufficient to distinguish between infected and non-infected samples immediately (T0′) or 15 min (T15′) after incubation, indicating its potential use as a point-of-care method as a screening strategy.publishersversionpublishe