Polyphasic delimitation of a filamentous marine genus, Capillus gen. nov. (Cyanobacteria, Oscillatoriaceae) with the description of two Brazilian species

Caires, Taiara A.,Lyra, Goia de M.,Hentschke, Guilherme S.,da Silva, Aaron Matheus S.,de Araujo, Valter L.,Sant'Anna, Celia L.,Nunes, Jose Marcos de C. The Korean Society of Phycology 2018 ALGAE Vol.33 No.4

Lyngbya C. Agardh ex Gomont is a nonheterocytous cyanobacterial genus whose evolutionary history is still poorly known. The traditionally defined Lyngbya has been demonstrated to be polyphyletic, including at least five distinct clades, some of which have been proposed as new genera. Intraspecific diversity is also clearly underestimated in Lyngbya due to the lack of unique morphological characters to differentiate species. In this study, we describe the new genus Capillus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes from benthic marine environments, including two new Brazilian species (here described as C. salinus T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes, and C. tropicalis T. A. Caires, C. L. Sant'Anna et J. M. C. Nunes), and two species yet to be described, one of them from India (Capillus sp. 2.1), and the other from United States of America, based on strain PCC 7419. Capillus species presented cross-wise diagonal fragmentation, assisted or not by necridic cells, which has not been previously mentioned for Lyngbya. Ultrastructural analyses showed that C. salinus and C. tropicalis have numerous gas vesicles, which are rarely described for benthic marine species. The new genus formed a well-supported clade, and the D1-D1' and Box B secondary structures of internal transcribed spacer also supported the proposal of its new species. These findings help to clarify the diversity of species in the Lyngbya complex and the taxonomy of the group, and highlight the need of further floristic surveys in tropical coastal environments, which remain poorly studied.

Polyphasic delimitation of a filamentous marine genus, Capillus gen. nov. (Cyanobacteria, Oscillatoriaceae) with the description of two Brazilian species

Taiara A. Caires,Goia de M. Lyra,Guilherme S. Hentschke,Aaron Matheus S. da Silva,Valter L. de Araújo,Célia L. Sant’Anna,José Marcos de C. Nunes 한국조류학회I 2018 ALGAE Vol.33 No.4

Lyngbya C. Agardh ex Gomont is a nonheterocytous cyanobacterial genus whose evolutionary history is still poorlyknown. The traditionally defined Lyngbya has been demonstrated to be polyphyletic, including at least five distinctclades, some of which have been proposed as new genera. Intraspecific diversity is also clearly underestimated in Lyngbyadue to the lack of unique morphological characters to differentiate species. In this study, we describe the new genusCapillus T. A. Caires, C. L. Sant’Anna et J. M. C. Nunes from benthic marine environments, including two new Brazilianspecies (here described as C. salinus T. A. Caires, C. L. Sant’Anna et J. M. C. Nunes, and C. tropicalis T. A. Caires, C. L. Sant’Anna et J. M. C. Nunes), and two species yet to be described, one of them from India (Capillus sp. 2.1), and the otherfrom United States of America, based on strain PCC 7419. Capillus species presented cross-wise diagonal fragmentation,assisted or not by necridic cells, which has not been previously mentioned for Lyngbya. Ultrastructural analyses showedthat C. salinus and C. tropicalis have numerous gas vesicles, which are rarely described for benthic marine species. Thenew genus formed a well-supported clade, and the D1-D1′ and Box B secondary structures of internal transcribed spaceralso supported the proposal of its new species. These findings help to clarify the diversity of species in the Lyngbya complexand the taxonomy of the group, and highlight the need of further floristic surveys in tropical coastal environments,which remain poorly studied.

High Efficiency Binding Aptamers for a Wide Range of Bacterial Sepsis Agents

( Ana Claudia Graziani ),( Maria Isabel Stets ),( Ana Luisa Kalb Lopes ),( Pedro Henrique Caires Schluga ),( Soledad Marton ),( Ieda Mendes Ferreira ),( Antero Silva Ribeiro De Andrade ),( Marco Aurel 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.4

Sepsis is a major health problem worldwide, with an extremely high rate of morbidity and mortality, partly due to delayed diagnosis during early disease. Currently, sepsis diagnosis requires bacterial culturing of blood samples over several days, whereas PCR-based molecular diagnosis methods are faster but lack sensitivity. The use of biosensors containing nucleic acid aptamers that bind targets with high affinity and specificity could accelerate sepsis diagnosis. Previously, we used the systematic evolution of ligands by exponential enrichment technique to develop the aptamers Antibac1 and Antibac2, targeting the ubiquitous bacterial peptidoglycan. Here, we show that these aptamers bind to four gram-positive and seven gram-negative bacterial sepsis agents with high binding efficiency. Thus, these aptamers could be used in combination as biological recognition elements in the development of biosensors that are an alternative to rapid bacteria detection, since they could provide culture and amplification-free tests for rapid clinical sepsis diagnosis.

A Submandibular Retropharyngeal Approach Improves Surgical Exposure

Henri Salle,François Caire 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Asymptotic Ergodic Capacity Analysis for MIMO Amplify-and-Forward Relay Networks

Kyoung-Jae Lee,Jin-Sung Kim,Caire, Giuseppe,Inkyu Lee IEEE 2010 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.9 No.9

<P>In this letter, we analyze asymptotic ergodic capacity of MIMO amplify-and-forward (AF) relaying systems which employ linear processing at the relay. By exploiting the asymptotic results for eigenvalue distributions, we derive the ergodic capacity in various asymptotic antenna regimes as a closed-form expression with arbitrary system parameters. The analyzed results demonstrate that increasing the number of source antennas causes the capacity shrink phenomenon which is analogous to the channel hardening effect in multi-user MIMO systems. Although we assume asymptotically large antennas to obtain the closed-form expressions, simulation results show that our derived expressions are surprisingly accurate even with the moderate number of antennas, and thus can serve for analyzing practical MIMO relay networks.</P>

Joint Spatial Division and Multiplexing—The Large-Scale Array Regime

Adhikary, Ansuman,Junyoung Nam,Jae-Young Ahn,Caire, Giuseppe IEEE 2013 IEEE transactions on information theory Vol.59 No.10

<P>We propose joint spatial division and multiplexing (JSDM), an approach to multiuser MIMO downlink that exploits the structure of the correlation of the channel vectors in order to allow for a large number of antennas at the base station while requiring reduced-dimensional channel state information at the transmitter (CSIT). JSDM achieves significant savings both in the downlink training and in the CSIT uplink feedback, thus making the use of large antenna arrays at the base station potentially suitable also for frequency division duplexing (FDD) systems, for which uplink/downlink channel reciprocity cannot be exploited. In the proposed scheme, the multiuser MIMO downlink precoder is obtained by concatenating a prebeamforming matrix, which depends only on the channel second-order statistics, with a classical multiuser precoder, based on the instantaneous knowledge of the resulting reduced dimensional “effective” channel matrix. We prove a simple condition under which JSDM incurs no loss of optimality with respect to the full CSIT case. For linear uniformly spaced arrays, we show that such condition is approached in the large number of antennas limit. For this case, we use Szego's asymptotic theory of Toeplitz matrices to show that a DFT-based prebeamforming matrix is near-optimal, requiring only coarse information about the users angles of arrival and angular spread. Finally, we extend these ideas to the case of a 2-D base station antenna array, with 3-D beamforming, including multiple beams in the elevation angle direction. We provide guidelines for the prebeamforming optimization and calculate the system spectral efficiency under proportional fairness and max-min fairness criteria, showing extremely attractive performance. Our numerical results are obtained via asymptotic random matrix theory, avoiding lengthy Monte Carlo simulations and providing accurate results for realistic (finite) number of antennas and users.</P>

Performance Analysis of Massive MIMO for Cell-Boundary Users

Yeon-Geun Lim,Chan-Byoung Chae,Caire, Giuseppe IEEE 2015 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.14 No.12

<P>In this paper, we consider massive multiple-input-multiple-output systems for both downlink and uplink scenarios, where three radio units connected via one digital unit support multiple user equipments at the cell-boundary through the same radio resource, i.e., the same time-frequency slot. For downlink transmitter options, the study considers zero forcing (ZF) and maximum ratio transmission (MRT), whereas for uplink receiver options, it considers ZF and maximum ratio combining (MRC). For the sum rate of each of these, we derive simple closed-form formulas. In the simple but practically relevant case where uniform power is allocated to all downlink data streams, we observe that, for the downlink, vector normalization is better for ZF whereas matrix normalization is better for MRT. For a given antenna and user configuration, we also analytically derive the signal-to-noise-ratio level below which MRC should be used instead of ZF. Numerical simulations confirm our analytical results.</P>

Wireless Multihop Device-to-Device Caching Networks

Jeon, Sang-Woon,Hong, Song-Nam,Ji, Mingyue,Caire, Giuseppe,Molisch, Andreas F. IEEE 2017 IEEE transactions on information theory Vol.63 No.3

<P>We consider a wireless device-to-device network, where n nodes are uniformly distributed at random over the network area. We let each node caches M files from a library of size m >= M. Each node in the network requests a file from the library independently at random, according to a popularity distribution, and is served by other nodes having the requested file in their local cache via (possibly) multihop transmissions. Under the classical 'protocol model' of wireless networks, we characterize the optimal per-node capacity scaling law for a broad class of heavy-tailed popularity distributions, including Zipf distributions with exponent less than one. In the parameter regime of interest, i.e., m = o(nM), we show that a decentralized random caching strategy with uniform probability over the library yields the optimal per-node capacity scaling of Theta(root M/m) for heavy-tailed popularity distributions. This scaling is constant with n, thus yielding throughput scalability with the network size. Furthermore, the multihop capacity scaling can be significantly better than for the case of single-hop caching networks, for which the per-node capacity is Theta(M/m). The multihop capacity scaling law can be further improved for a Zipf distribution with exponent larger than some threshold >1, by using a decentralized random caching uniformly across a subset of most popular files in the library. Namely, ignoring a subset of less popular files (i.e., effectively reducing the size of the library) can significantly improve the throughput scaling while guaranteeing that all nodes will be served with high probability as n increases.</P>

Laccase Induced Maize Bran Arabinoxylan Gels

Claudia M. Berlanga-Reyes,Elizabeth Carvajal-Millan,Graciela Caire Juvera,Agustin Rascon-Chu,Jorge A. Marquez-Escalante,Ana Luisa Martinez-Lopez 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.4

The aim of this research was to study the structural and rheological properties of gels formed by ferulated maize bran arabinoxylans (MBAX) at different concentrations. MBAX was cross-linked by a laccase leading to the formation of dimers and trimers of ferulic acid (di-FA, tri-FA) as covalent cross-link. An increase in MBAX gels elasticity (from 11 to 20 ㎩) as well as lower mesh size (from 80 to 48 ㎚) were obtained by augmenting the MBAX concentration from 2.5 to 3.5%(w/v), respectively, but no increase in di-FA and tri-FA content was obtained (0.03 and 0.014 ㎍/㎎ MBAX, respectively).