Chaotic properties of an FIR filtered H\'enon map

When chaotic signals are used in practical communication systems, it is essential to control and eventually limit the spectral bandwidth occupied by these signals. One way to achieve this goal is to insert a discrete-time filter into a nonlinear map that generates chaotic signals. However, this can completely change the dynamic properties of the original map. Considering this situation, this paper presents a series of numerical experiments aimed at obtaining the Lyapunov exponents of the signals generated by the two-dimensional H\'enon map with a set of prototypical finite impulse response (FIR) filters added in the feedback loop. Our results show that the number of filter coefficients and the location of the zeros have a significant and complex impact on the behavior of the generated signals. Therefore, FIR filters should be carefully designed to preserve or suppress chaos in practical applications.Comment: Published at Communications in Nonlinear Science and Numerical Simulation (Elsevier) https://doi.org/10.1016/j.cnsns.2024.10784

O sistemismo de Bunge como base teórico-metodológica para pesquisa em Ciência da Informação

This paper aims at bringing Mario Bunge's theoretical contributions to the scientific enterprise into the realm of Information Science. The study is justified by the area's interdisciplinary nature and its constant need for interaction with other knowledge areas. It is a theoretical essay based on the analysis of information science concepts and on Bunge's systemism. We further extend the study with the application of fundamentals of systemism in two related studies, one descriptive, other explanatory, on institutional repositories, thus exemplifying research conduction under the fundamental epistemic operation in systemism: the reduction to the system

O sistemismo de Bunge como base teórico-metodológica para pesquisa em Ciência da Informação

This paper aims at bringing Mario Bunge's theoretical contributions to the scientific enterprise into the realm of Information Science. The study is justified by the area's interdisciplinary nature and its constant need for interaction with other knowledge areas. It is a theoretical essay based on the analysis of information science concepts and on Bunge's systemism. We further extend the study with the application of fundamentals of systemism in two related studies, one descriptive, other explanatory, on institutional repositories, thus exemplifying research conduction under the fundamental epistemic operation in systemism: the reduction to the system

Global systematic map of research on bats in agricultural systems

Introduction: The conversion of natural habitats to agricultural systems is one of the main global threats to bats. Here, we aimed to develop a systematic mapping to identify publication trends and research gaps in studying bats and agricultural systems. Methods: We reviewed 309 studies published between 1990 and 2021 that sampled bats in agricultural systems or evaluated the effect of these systems on these animals. Results: We found that most studies were conducted in the Palearctic and Neotropical regions (55.3%) and forest biomes (66.0%). Grassland-cropland systems (50.2%) and forest plantations that do not require cutting during the extraction of their products (47.9%) were more studied than forest plantations that require cutting (19.7%). Additionally, acoustic recordings (41.1%) and mist nets (34.3%) were the primary sampling methods used, with few studies combining these methods (7.1%). Also, most studies were conducted on a local scale (77.7%). The number of landscape-scale studies was smaller (34.3%) and concentrated in the Palearctic region (39.6%). Most studies assessed how agricultural systems affect biodiversity (62.1%). However, the phylogenetic and functional dimensions and b-diversity were little explored, with 2.5% and 23.3% of the biodiversity studies, respectively. Of the proposed mitigation measures, the most cited was including natural/semi-natural/potential bat habitats in cultivated landscapes (59.5%). Discussion: In summary, our findings highlight the need for attention to the Afrotropic and Indo-Malaysia regions; predominantly non-forested biomes; plantations that require cutting during the extraction of their products; combined use of different sampling methods, as well as other methods as telemetry; use of multiple biodiversity descriptors and others biological descriptors, such as ecological services; landscape-scale studies and the role of conservation policies in promoting their conservation and raising awareness of their importance among producers and local communities. Filling these knowledge gaps is necessary to understand the factors influencing bat survival in cultivated landscapes. This is the only way to develop management and conservation strategies in these landscapes.info:eu-repo/semantics/publishedVersio

Chemical Composition and Botanical Origin of Red Propolis, a New Type of Brazilian Propolis

Red propolis is a new type of Brazilian propolis. This material, as well as the secretions of 20 plant species that are often mentioned as its probable botanical source, have been investigated by RP-HPTLC. Phytochemical evidence based on UV-VIS spectra, RP-HPLC and GC-MS, showed Dalbergia ecastophyllum (L.) Taub. to be the main source of red propolis in Alagoas state. The propolis and plant resin showed high relative percentages of the isoflavonoids 3-Hydroxy-8,9-dimethoxypterocarpan and medicarpin. To our knowledge this is the first report of the secretion of a leguminous species being the source of propolis

Physicochemical properties and cell viability of shrimp chitosan films as affected by film casting solvents. I-potential use as wound dressing

: Chitosan solubility in aqueous organic acids has been widely investigated. However, most of the previous works have been done with plasticized chitosan films and using acetic acid as the film casting solvent. In addition, the properties of these films varied among studies, since they are influenced by different factors such as the chitin source used to produce chitosan, the processing variables involved in the conversion of chitin into chitosan, chitosan properties, types of acids used to dissolve chitosan, types and amounts of plasticizers and the film preparation method. Therefore, this work aimed to prepare chitosan films by the solvent casting method, using chitosan derived from Litopenaeus vannamei shrimp shell waste, and five different organic acids (acetic, lactic, maleic, tartaric, and citric acids) without plasticizer, in order to evaluate the effect of organic acid type and chitosan source on physicochemical properties, degradation and cytotoxicity of these chitosan films. The goal was to select the best suited casting solvent to develop wound dressing from shrimp chitosan films. Shrimp chitosan films were analyzed in terms of their qualitative assessment, thickness, water vapor permeability (WVP), water vapor transmission rate (WVTR), wettability, tensile properties, degradation in phosphate buffered saline (PBS) and cytotoxicity towards human fibroblasts using the resazurin reduction method. Regardless of the acid type employed in film preparation, all films were transparent and slightly yellowish, presented homogeneous surfaces, and the thickness was compatible with the epidermis thickness. However, only the ones prepared with maleic acid presented adequate characteristics of WVP, WVTR, wettability, degradability, cytotoxicity and good tensile properties for future application as a wound dressing material. The findings of this study contributed not only to select the best suited casting solvent to develop chitosan films for wound dressing but also to normalize a solubilization protocol for chitosan, derived from Litopenaeus vannamei shrimp shell waste, which can be used in the pharmaceutical industry.info:eu-repo/semantics/publishedVersio

Análise dos riscos de segurança nos laboratórios de Química da rede pública e particular de ensino em Caruaru-PE.

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Battery-like behavior of Ni-ceria based systems: synthesis, surface defects and electrochemical assessment

NiO, CeO2 and respective composites are extensively used in energy storage devices due to mostly their high electrochemical activity. However, the assessment of battery-like behavior of Ni-ceria based systems comprising (Ni or Gd)-doped ceria combined with NiO seems to be neglected in the literature. In this work, NiO and ceria-based solid solutions composite powders were obtained by a co-precipitation synthesis method. The structure and particle size of the calcined powders were investigated by X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM), respectively. Oxidative states of composites were inspected by X-ray photoelectron spectroscopy (XPS). The electrochemical performance of powders was evaluated by cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy. Refinement of the XRD patterns showed that powders have nanosized crystallites and mean size of particles within 20 – 70 nm were revealed by FESEM. The improved specific capacity of the NiO-CeO2 electrode material (about 2.5 times higher than that of NiO-CGO at 5 mV s−1) is due to an increase in Faradic reactions taken place on its surface with a higher fraction of defects (namely Ni3+, Ce3+ and oxygen vacancies), as determined by XPS. The superior electrochemical performance of the NiO-CeO2 electrode is also confirmed by electrochemical impedance spectroscopy.publishe

Agronomic biofortification of cowpea with selenium: effects of selenate and selenite applications on selenium and phytate concentrations in seeds

BACKGROUNDSelenium (Se) is a nutrient for animals and humans, and is considered beneficial to higher plants. Selenium concentrations are low in most soils, which can result in a lack of Se in plants, and consequently in human diets. Phytic acid (PA) is the main storage form of phosphorus in seeds, and it is able to form insoluble complexes with essential minerals in the monogastric gut. This study aimed to establish optimal levels of Se application to cowpea, with the aim of increasing Se concentrations. The efficiency of agronomic biofortification was evaluated by the application of seven levels of Se (0, 2.5, 5, 10, 20, 40, and 60 g ha−1) from two sources (selenate and selenite) to the soil under field conditions in 2016 and 2017.RESULTSApplication of Se as selenate led to greater plant Se concentrations than application as selenite in both leaves and grains. Assuming human cowpea consumption of 54.2 g day−1, Se application of 20 g ha−1 in 2016 or 10 g ha−1 in 2017 as selenate would have provided a suitable daily intake of Se (between 20 and 55 μg day−1) for humans. Phytic acid showed no direct response to Se application.CONCLUSIONSelenate provides greater phytoavailability than selenite. The application of 10 g Se ha−1 of selenate to cowpea plants could provide sufficient seed Se to increase daily human intake by 13–14 μg d−1. © 2019 Society of Chemical Industr

A fáscia transversal e o colágeno na hérnia inguinal direta

OBJECTIVE: The main objective os the present work is to identify the constitutive elements of 23 samples of tranversalis fascia from direct inguinal hernia patients compairing to 22 fascia from corpses.MATERIAL AND METHODS: The samples were obtained at the moment of videolaparospic repair. They were stained for haematoxiline-eosine and immunohistochemistry with collagen type I monoclonal antibody.RESULTS: The dense connective tissue was the principal constitutive element in both groups, although less present in the patient one, followed by adipose tissue. We were able to identify, by immunohistochemistry, the type I collagen as the main protein.CONCLUSION: The authors conclude that transversalis fascia is mainly formed by type I collagen and suggest to use hernia repair technics that increase the collagen deposition in fascia, like when using mesh.OBJETIVO: O objetivo do presente estudo é o de identificar os elementos histológicos constituintes da fáscia transversal em 23 pacientes com hérnia inguinal direta, comparando-os com a fáscia de 22 cadáveres sem esta doença.MATERIAIS E MÉTODOS: As biópsias dos pacientes foram obtidas no momento da correção videolaparoscópica. As fáscias foram estudadas histologicamente, sendo empregadas as técnicas de coloração de hematoxilina-eosina e anticorpo monoclonal para colágeno tipo I.RESULTADOS: O tecido conjuntivo denso foi o principal elemento constitutivo das fáscias de pacientes e controles, embora em menor presença nos primeiros, seguido do tecido adiposo. Identificamos, através da técnica de imuno-histoquímica, o colágeno tipo I como sendo a principal proteína das fáscias.CONCLUSÃO: Os autores concluem que a fáscia transversal é constituída principalmente por colágeno tipo I e sugerem o uso de técnicas de correção de hérnia inguinal que aumentem a deposição de colágeno na fáscia, como quando do uso de próteses