End-to-end deep learning of geometric shaping for unamplified coherent systems.

With the increasing data rate requirements on short-reach links, the recent standardization of unamplified coherent optical systems is paving the way for a cost and power-effective solution, targeting a massive deployment in the near future. However, unamplified systems are introducing new challenges. Particularly, the performance is highly dependent on the peak-to-average power ratio (PAPR) of the transmitted signal, which puts at question the use of the typical constellation formats. In this work, we use an end-to-end deep learning framework to optimize the geometry of different constellation sizes, ranging from 8- to 128-ary constellations. In general, it is shown that the performance of these systems is maximized with constellations whose outer symbols are disposed in a square shape, owing to the minimization of the real-valued PAPR. Following this premise, we experimentally demonstrate that odd-bit constellations can be significantly optimized for unamplified coherent links, achieving power budget gains in the range of 0.5-3 dB through the geometric optimization of 8-, 32- and 128-ary constellations.

Resposta hematológica do cascudo ornamental amazônico Peckoltia oligospila ao estresse de transporte / Hematological response of Amazonian ornamental Peckoltia oligospila subjected to stress by transportation

O objetivo deste trabalho foi avaliar as respostas hematológicas do acari-bola Peckoltia oligospila submetido ao estresse de transporte. Variações nos parâmetros de sangue foram analisadas às zero, seis, 24, 48, 72 e 96 horas após o transporte. Respostas ao estresse foram observadas entre zero e seis horas do transporte, mas a maioria dos parâmetros retornou aos valores basais em 24 horas. O tempo de zero hora (momento imediato após transporte) foi o mais crítico, com valores elevados de glicemia, eritrócitos e eritroblastos. Respostas secundárias tardias foram observadas para a proteína plasmática total, o volume corpuscular médio (VCM) e a hemoglobina corpuscular média (HCM) em seis horas após o transporte dos peixes, retornando aos valores basais após esse período. O número de leucócitos não sofreu alterações após o transporte. O estresse de transporte não comprometeu a fisiologia de P. oligospila, o que indica que esse peixe é resistente ao estresse se comparado com outras espécies. Porém, recomenda-se que não se realize qualquer outro procedimento estressante durante pelo menos 24 horas da recuperação dos peixes após transporte, para garantir a saúde e a sobrevivência dos animais transportados.(AU)

The objective of this work was to evaluate the hematological responses of bola-pleco (Peckoltia oligospila) undergoing the stress of transportation. Variations on blood parameters were analyzed at 0, 6, 24, 48, 72 and 96h after transportation. Responses to stress were detected from 0 to 6h after the transportation of fish, however, most parameters returned to baselines values within 24h of transportation. The moment of 0h was the most critical, presenting higher values of glycemia, erythroblasts and erythrocytes. Late secondary responses were observed to total plasmatic protein, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) at 6h, returning to baselines values after this time. Leukocyte number was not affected by stress of transportation. The stress by transportation was not severe to influence the health of P. oligospila, indicating that fish is resistant to stress if compared to other species. However, we recommended no stressful procedures for at least 24 hours for recovery, in order to ensure health and survival of fish.(AU)

Prevention of suicide phenomenon in aeromonads.

Clinical isolates of Aeromonas (13 Aeromonas caviae), 8 Aeromonas hydrophila, 3 Aeromonas spp., and 2 Aeromonas media recovered from diarrheal feces of children were submitted to the suicide phenomenon test and investigated at intervals of 24 h for up to 120 h. The same isolates were also stimulated by repeated passages in broth for ten days before the test. After the bacterial stimulus, a decreases in the number of aeromonads with suicidal capacity was observed. The suicide phenomenon was expressed after 72 h of incubation in only some isolates. The results show that the suicide phenomenon can be prevented by stimulation of bacterial metabolism.

Aeromonas species exhibit aggregative adherence to HEp-2 cells.

Clinical and environmental isolates of Aeromonas species (five A. hydrophila isolates, three A. caviae isolates, and two A. sobria isolates) were tested for their adherence to HEp-2 cells. Clinical isolates of A. hydrophila and A. sobria exhibited aggregative adherence similar to that presented by enteroadherent-aggregative Escherichia coli. Bacterial aggregates adhered to cells with a typical "stacked-brick" appearance. In contrast, A. caviae strains showed a diffuse adherence pattern.

Production of enterotoxin and cytotoxin by Aeromonas veronii.

Fourteen strains of Aeromonas veronii were isolated from salt and fresh water in Rio de Janeiro and investigated for the presence of virulence factors. Eleven (79%) A. veronii strains were positive for enterotoxin by the suckling-mouse test and thirteen (93%) produced hemolysin. Of the 13 A. veronii strains that produced hemolysin, seven were investigated for cytotoxin production using Vero cells as indicator cells and all of them were positive.

Production of enterotoxin and cytotoxin by aeromonas veronii

Fourteen strains of Aeromonas veronii were isolated from salt and fresh water in Rio de Janeiro and investigated for the presence of birulence factors. Eleven (79%) A. veronii strains were positive for enterotoxin by the suckling-mouse test and thirteen (93%) produced hemolysin. Of the 13 A. veronii strains that produced hemolysin, seven were investigated for cytotoxin production using Vero cells as indicator cells and all of them were positive