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Copyright of Revista de la Biblioteca Nacional Jose Marti is the property of Biblioteca Nacional de Cuba Jose Marti and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Didasc@lia: Didáctica y Educación is the property of Universitaria de Las Tunas, Centro de Estudios de Didactica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main objective of the work presented here is to speed up artificial neural network training using parallel processing. Backpropagation neural network was selected for this research, since it has attracted most interest among neural network researchers. This article describes the implementations and experiments undertaken for selected model of neural network. The parallel program can execute efficiently for a large range of neural applications. One real neural application has been used in this work to test the implemented parallel algorithm on workstation cluster. The results show that it is beneficial to use parallel processing for neural network training, obtaining better performance on a large system than on a small one. [ABSTRACT FROM AUTHOR]

There are few studies dedicated to species of the Order Parmales all over the world. All 12 taxa described are part of the marine ultraplankton (less than 5 μm). Analysis of filtered samples from the Gulf of Tehuantepec yielded specimens of two taxa of the group. One is a new species, belonging to the genus T etraparma . T etraparma insecta sp. nov. is solitary and spherical (2.8–3.8 μm diameter), and all plates lack ornamentations or knobs, the walls are smooth, and only the plate junctions are seen. The shield plates are convex and show a conspicuous rim, some of them with an indentation. This species shows superficial similarities with T etraparma pelagica , the other species described of the genus, and is very similar to siliceous forms, previously found, with no formal name. The other species is the taxon Triparma laevis form mexicana (Kosman) stat. nov., earlier described for Mexican waters, which has an irregular ala, the shield plates have knobs at the center, the triradiate plates show a “Y”-shaped keel, and the walls of plates and ala show minute granules. T etraparma insecta was distributed widely in the study area and was relatively abundant, reaching a density of 4 × 104 ·L-1 , with an evident preference for subsurface waters (10–20 m depth), whereas T. laevis form mexicana was rare and scarce. Both species seem to be restricted to tropical–subtropical waters. We discuss the taxonomy of Parmales, especially concerning the category of subspecies within the group. Parmales is a widespread group in cold and tropical waters. [ABSTRACT FROM AUTHOR]

There are few studies dedicated to species of the Order Parmales all over the world. All 12 taxa described are part of the marine ultraplankton (less than 5 μm). Analysis of filtered samples from the Gulf of Tehuantepec yielded specimens of two taxa of the group. One is a new species, belonging to the genus T etraparma . T etraparma insecta sp. nov. is solitary and spherical (2.8–3.8 μm diameter), and all plates lack ornamentations or knobs, the walls are smooth, and only the plate junctions are seen. The shield plates are convex and show a conspicuous rim, some of them with an indentation. This species shows superficial similarities with T etraparma pelagica , the other species described of the genus, and is very similar to siliceous forms, previously found, with no formal name. The other species is the taxon Triparma laevis form mexicana (Kosman) stat. nov., earlier described for Mexican waters, which has an irregular ala, the shield plates have knobs at the center, the triradiate plates show a “Y”-shaped keel, and the walls of plates and ala show minute granules. T etraparma insecta was distributed widely in the study area and was relatively abundant, reaching a density of 4 × 104 ·L-1 , with an evident preference for subsurface waters (10–20 m depth), whereas T. laevis form mexicana was rare and scarce. Both species seem to be restricted to tropical–subtropical waters. We discuss the taxonomy of Parmales, especially concerning the category of subspecies within the group. Parmales is a widespread group in cold and tropical waters. [ABSTRACT FROM AUTHOR]

The present work deals with the use of biphasic codes for their application as an exciting signal in pulse compression radars. Its main characteristics are exposed and the digital design of sections for modulation, reception and compression is described. Very High-Speed Integrated Circuit Hardware Description Language (VHDL) was used for its implementation and MATLAB® for simulation, modelling and synthesis in VHDL of functional blocks. A 32-bits code is used with witch a 20.56 dB Peak to Sidelobe Level Ratio (PSR) is guaranteed. The contribution of the proposal lies in the demonstration of two convolution synthesis methods for the BPSK signal. Is presented and described its finite difference equation that define both of the convolution methods and also presented main resources used for their synthesis on DE10-Standard Development Kit. [ABSTRACT FROM AUTHOR]

Background: Available data regarding clinical profile and management of elderly patients with atrial fibrillation (AF) according to dependency, fragility and cognitive impairment are scarce. The objective of the study was to analyze the biodemographic data, clinical profile and antithrombotic treatment according to dependency, fragility and cognitive impairment in elderly AF patients., Methods: Cross-sectional and multi-center study performed in consecutive AF patients ≥ 75 years treated with oral anticoagulants ≥ 3 months attended in Internal Medicine Departments in Spain., Results: A total of 837 patients (83.0 ± 5.0 years; CHA 2 DS 2 -VASc: 5.0 ± 1.4; HAS-BLED: 2.1 ± 0.9) were included. 44.4% of patients had some degree of dependency, 43.3% were fragile, and 32.3% had cognitive impairment. Patients with any of these conditions were older, had a worse clinical profile, with more comorbidities and higher risks of thromboembolic and bleeding events. All these conditions were independently associated among them. Overall, 70.8% of patients were taking vitamin K antagonists, the remaining 29.2% direct oral anticoagulants and 9.7% oral antiplatelets. This distribution was independent of the presence of dependency or fragility, but there was a trend to a higher prescription of vitamin K antagonists in those patients with cognitive impairment (75.2% vs . 68.8%; P = 0.05)., Conclusions: Approximately 32%-44% of elderly anticoagulated AF patients attended have some degree of dependency, fragility and/or cognitive impairment. Patients with any of these conditions are older and have a worse clinical profile. Approximately 71% of patients are taking vitamin K antagonists, regardless dependency or frailty, but with a trend to higher prescription in patients with cognitive impairment.

The phytoflagellates are a heterogeneous group of autotrophic, heterotrophic and mixothrophic flagellates of trophic importance in several ecosystems. As in the rest of Latin America, the phytoflagellates that occur in the Mexican Pacific coasts are virtually unknown except for a few records. Their study require complicated collection and analysis methods, a probable cause for the scarce knowledge of this group in tropical and subtropical areas. Material recently collected from various localities along the Mexican Pacific coasts was used to study phytoflagellates, including toxic and potentially toxic species. Plankton samples were treated by gravity and pump filtration, using different methods for fixation and analysis. The phyla Euglenophyta, Heterokontophyta and Haptophyta were found. They occur as plankton in oceanic and shallow coastal waters.