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1.
One Health ; 17: 100586, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37415721

RESUMEN

Wild birds have emerged as novel reservoirs and potential spreaders of antibiotic-resistant priority pathogens, being proposed as sentinels of anthropogenic activities related to the use of antimicrobial compounds. The aim of this study was to investigate the occurrence and genomic features of extended-spectrum ß-lactamase (ESBL)-producing bacteria in wild birds in South America. In this regard, we have identified two ESBL (CTX-M-55 and CTX-M-65)-positive Escherichia coli (UNB7 and GP188 strains) colonizing Creamy-bellied Thrush (Turdus amaurochalinus) and Variable Hawk (Geranoaetus polyosoma) inhabiting synanthropic and wildlife environments from Brazil and Chile, respectively. Whole-genome sequence (WGS) analysis revealed that E. coli UNB7 and GP188 belonged to the globally disseminated clone ST602, carrying a wide resistome against antibiotics (ß-lactams), heavy metals (arsenic, copper, mercury), disinfectants (quaternary ammonium compounds), and pesticides (glyphosate). Additionally, E. coli UNB7 and GP188 strains harbored virulence genes encoding hemolysin E, type II and III secretion systems, increased serum survival, adhesins and siderophores. SNP-based phylogenomic analysis, using an international genome database, revealed genomic relatedness (19-363 SNP differences) of GP188 with livestock and poultry strains, and genomic relatedness (61-318 differences) of UNB7 with environmental, human and livestock strains (Table S1), whereas phylogeographical analysis confirmed successful expansion of ST602 as a global clone of One Health concern. In summary, our results support that ESBL-producing E. coli ST602 harboring a wide resistome and virulome have begun colonizing wild birds in South America, highlighting a potential new reservoir of critical priority pathogens.

2.
Sensors (Basel) ; 23(11)2023 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-37300040

RESUMEN

By enabling multiple non-orthogonal transmissions, power domain non-orthogonal multiple access (PD-NOMA) potentially increases a system's spectral efficiency. This technique can become an alternative for future generations of wireless communication networks. The efficiency of this method fundamentally depends on two previous processing steps: an appropriate grouping of users (transmission candidates) as a function of the channel gains and the choice of power levels that will be used to transmit each signal. Thus far, the solutions presented in the literature to address the problems of user clustering and power allocation do not consider the dynamics of communication systems, i.e., the temporal variation in the number of users and the channel conditions. In order to consider these dynamic characteristics in the clustering of users in NOMA systems, this work proposes a new clustering technique based on a modification of the DenStream evolutionary algorithm, chosen for its evolutionary capacity, noise robustness and online processing. We evaluated the performance of the proposed clustering technique considering, for simplicity, the use of an already widely known power allocation strategy called improved fractional strategy power allocation (IFSPA). The results show that the proposed clustering technique can follow the system dynamics, clustering all users and favoring the uniformity of the transmission rate between the clusters. Compared to orthogonal multiple access (OMA) systems, the proposed model's gain was approximately 10%, obtained on a challenging communication scenario for NOMA systems since the channel model adopted does not favor a large difference in the channel gains between users.


Asunto(s)
Noma , Humanos , Algoritmos , Evolución Biológica , Análisis por Conglomerados , Registros
3.
Zookeys ; 1092: 63-77, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35586292

RESUMEN

Petalacmis Olivier, 1908 is a poorly known genus of firefly endemic to South America and is currently the only member of the subfamily Lampyrinae, tribe Lampyrini known to occur on the continent. Here, we describe a new species, Petalacmistriplehorni sp. nov. from Bolivia and compare it to the two other described species in the genus. A key to Petalacmis species based on male traits, as well as illustrations of morphological features, are given in detail for the first time. We present unique, previously neglected traits of Petalacmis species and compare them to other Lampyrinae.

4.
Zookeys ; 1114: 131-166, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36761699

RESUMEN

Amydetinae is an exclusively Neotropical subfamily of fireflies, distributed among three genera: Amydetes Illiger, 1807, Magnoculus McDermott, 1964, and Memoan Silveira & Mermudes, 2013. Here, we describe three new species of Amydetinae: two belonging to Amydetes (A.alexi sp. nov. and A.marolae sp. nov.) and one to the previously monotypic Memoan (Me.conani sp. nov.). All three species are known only from the Atlantic Forest in southeastern Brazil. Endoskeletal structures of Memoan and Magnoculus species are described and compared with those of Amydetes for the first time. After studying the type material, Photinusfruhstorferi Pic, 1942 is transferred to Memoan, generating Memoanfruhstorferi comb. nov., and Me.ciceroi Silveira & Mermudes, 2013 syn. nov. is placed as a junior synonym. We also redescribe Magnoculusobscurus Olivier, 1885 and compare it to other species of genus and to other amydetine taxa to identify potential new diagnostic traits for the Amydetinae and its constituting genera. We provide an updated diagnosis for Memoan, illustrations for all four species, and a distribution map for the three new species, as well as a key to adult males of the three amydetine genera, and an updated key to Amydetes species based on males.

5.
Zootaxa ; 4585(1): zootaxa.4585.1.4, 2019 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-31716182

RESUMEN

Here, we propose Uanauna gen. nov. (Lampyridae: Photinini), a new monotypic genus of fireflies endemic to the Brazilian Atlantic Forest. Uanauna angaporan sp. nov. occurs in Submontane and Montane forest habitats at the Serra do Mar mountain range, in the Southern Fluminense region (Rio de Janeiro State, Southeastern Brazil). The new species was recorded both on the mainland, at the municipality of Itaguaí and Rio de Janeiro, and at the continental island of Ilha Grande, in Angra dos Reis, at the Rio de Janeiro State. An occurrence map and illustrations of diagnostic features are given for the new taxa, as well as a key to Lucidotina genera in Brazil.


Asunto(s)
Luciérnagas , Animales , Brasil , Ecosistema , Bosques
6.
Sensors (Basel) ; 19(19)2019 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-31569389

RESUMEN

This work presents a novel spectral sensing method for the detection of signals presenting nonlinear phase variation over time. The introduced method is based on the angle-time cyclostationarity theory, which applies transformations to the signal to be sensed in order to mitigate the effects of nonlinear phase variation. The architecture is employed for sensing binary phase shift keying (BPSK) signals, being also compared with time cyclostationarity. The obtained simulation results clearly demonstrate the efficiency of the proposed approach, while presenting improved performance in terms of the detection rate of primary users increased by about 8 dB.

7.
Zootaxa ; 4413(1): 173-186, 2018 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-29690126

RESUMEN

Luciuranus Silveira, Khattar Mermudes, 2016 is a firefly genus whose species bear an intricate, species-specific lock-and-key mechanism of reproductive isolation. Here we propose four new species, Luciuranus magnoculus sp. nov., L. desideratus sp. nov., L. takiyae sp. nov. and L. carioca sp. nov., and provide illustrations of their diagnostic features and an updated key to species. As previously reported for their congenerics, each of the four new species have stereotypical morphology of both male and female terminalia, and are regarded as prima facie endemics of single massifs of the Serra da Mantiqueira and Serra do Mar, in the Brazilian Atlantic Rainforest.


Asunto(s)
Luciérnagas , Estructuras Animales , Animales , Brasil , Escarabajos , Femenino , Masculino , Bosque Lluvioso
8.
Sensors (Basel) ; 17(12)2017 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-29236048

RESUMEN

Wireless control systems can sense, control and act on the information exchanged between the wireless sensor nodes in a control loop. However, the exchanged information becomes susceptible to the degenerative effects produced by the multipath propagation. In order to minimize the destructive effects characteristic of wireless channels, several techniques have been investigated recently. Among them, wavelet coding is a good alternative for wireless communications for its robustness to the effects of multipath and its low computational complexity. This work proposes an adaptive wavelet coding whose parameters of code rate and signal constellation can vary according to the fading level and evaluates the use of this transmission system in a control loop implemented by wireless sensor nodes. The performance of the adaptive system was evaluated in terms of bit error rate (BER) versus E b / N 0 and spectral efficiency, considering a time-varying channel with flat Rayleigh fading, and in terms of processing overhead on a control system with wireless communication. The results obtained through computational simulations and experimental tests show performance gains obtained by insertion of the adaptive wavelet coding in a control loop with nodes interconnected by wireless link. These results enable the use of this technique in a wireless link control loop.

9.
Sensors (Basel) ; 17(9)2017 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-28869536

RESUMEN

We propose an approach for the synchronization of video streams using correntropy. Essentially, the time offset is calculated on the basis of the instantaneous transfer rates of the video streams that are extracted in the form of a univariate signal known as variable bit-rate (VBR). The state-of-the-art approach uses a window segmentation strategy that is based on consensual zero-mean normalized cross-correlation (ZNCC). This strategy has an elevated computational complexity, making its application to synchronizing online data streaming difficult. Hence, our proposal uses a different window strategy that, together with the correntropy function, allows the synchronization to be performed for online applications. This provides equivalent synchronization scores with a rapid offset determination as the streams come into the system. The efficiency of our approach has been verified through experiments that demonstrate its viability with values that are as precise as those obtained by ZNCC. The proposed approach scored 81 % in time reference classification against the equivalent 81 % of the state-of-the-art approach, requiring much less computational power.

10.
Aust Endod J ; 37(2): 70-2, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21771186

RESUMEN

The aim of this study was to analyse in vivo the accuracy of two apex locators, Root ZX and Novapex, to determine the position of the apical constriction. Twenty-three human single-rooted teeth to be extracted for periodontal reasons constituted the experiment. Endodontic access was obtained and the apical constriction was determined by one of the apex locators after initial crown-down preparation. When the electronic marker indicated that the tip of the endodontic file was at the apical constriction, the teeth were filled with composite and then surgically removed. The presence of the endodontic file tip at the apical constriction was evaluated stereomicroscopically (30×) and confirming radiographs were exposed. The accuracy of Root ZX and Novapex was 91.7% and 81.8% respectively. Within the limits of this study, the evaluated apex locators have a similar clinical performance for the apical constriction location.


Asunto(s)
Cavidad Pulpar/anatomía & histología , Odontometría/instrumentación , Ápice del Diente/anatomía & histología , Diente Premolar/anatomía & histología , Diente Canino/anatomía & histología , Cavidad Pulpar/diagnóstico por imagen , Equipos y Suministros Eléctricos/normas , Humanos , Incisivo/anatomía & histología , Odontometría/normas , Radiografía , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/diagnóstico por imagen
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