Enhanced optical gain clamping for upstream packet based traffic on hybrid WDM/TDM-PON using fiber bragg grating

In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An mprovement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 d

Phoma sp. (sect. Peyronellaea), as causal agent of leaf spot on Paspalum atratum in Brazil

Phoma sp. (sect. Peyronellaea) foi consistentemente isolado de plantas de Paspalum atratum cv. Pojuca (capim Pojuca) com sintomas de manchas foliares em uma população no Distrito Federal, em 2002. Os conídios mostraram-se hialinos, predominantemente elípticos, unicelulares, gutulados, medindo entre 2,50-5,25 mim de largura e 10,25-17,25 mim de comprimento. Os picnídios mostraram-se escuros, medindo entre 100-310 mim de diâmetro, com pescoço curto, na maioria são globosos e solitários. Clamidósporos multicelulares, freqüentemente semelhantes a conídios de Alternaria foram observados nas colônias. Testes de patogenicidade em casa de vegetação e o ubsequente reisolamento do fungo confirmaram a hipótese de que Phoma sp. é o agente etiológico das manchas foliares de capim Pojuca. Os primeiros sintomas apareceram em todas as plântulas inoculadas, quatro a cinco dias após a inoculação. Sete outras espécies de gramíneas foram suscetíveis ao fungo. A ocorrência de manchas foliares de capim Pojuca causadas por Phoma sp. é relatada pela primeira vez no Brasil.The fungus Phoma sp. (sect. Peyronellaea) was consistently isolated from infected Paspalum atratum cv. Pojuca (Pojuca grass) plants with leaf spot symptoms in the Federal District, Brazil, in 2002. Conidia were hyaline, usually ellyptical, unicellular, gutullate, 2,50-5,25 x 10,25-17,25 mum. Pycnidia were mostly solitary, 100-310 mum diameter, globose, usually with a short neck. Multicellular chlamidospores often resembling conidia of Alternaria were present in the colonies. Pathogenicity tests under greenhouse conditions and subsequent reisolations of Phoma sp. from artificially inoculated Pojuca seedlings confirmed the hypothesis that this fungus was the causal agent of the disease. Symptoms of leaf spot appeared four to five days after inoculation in 100% of the inoculated Pojuca grass plants. All seven species of grasses evaluated were susceptible to this fungus. The occurrence of leaf spots of Pojuca grass caused by Phoma sp. is reported for the first time in Brazil

Occurrence of Bipolaris maydis causing leaf spot in Paspalum atratum cv. ojuca in Brazil

Bipolaris maydis foi consistentemente isolado de plantas de Paspalum atratum cv. Pojuca com sintomas de manchas foliares em 100% das plantas de uma população no Cerrado, em 2002. Testes de patogenicidade em casa de vegetação e o subseqüente reisolamento do fungo confirmaram a hipótese de que B. maydis é o agente etiológico da mancha foliar de P. atratum cv. Pojuca. Os primeiros sintomas apareceram em todas as mudas inoculadas, quatro a cinco dias após a inoculação. Sete outras espécies de gramíneas foram suscetíveis ao fungo. A ocorrência de manchas foliares de Pojuca causadas por B. maydis é relatada pela primeira vez no Brasil.Bipolaris maydis was consistently isolated from infected Paspalum atratum cv. Pojuca plants showing leaf spot symptoms in the Cerrado of Brazil, in 2002. Pathogenicity tests under greenhouse conditions and subsequent reisolations of B. maydis from artificially inoculated Pojuca seedlings confirmed the hypothesis that this fungus was the causal agent of the disease. Symptoms of leaf spot appeared four days after inoculation in 100% of the inoculated Pojuca plants. All seven species of grasses evaluated were susceptible to B. maydis. The occurrence of leaf spot of Pojuca caused by B. maydis is reported for the first time in Brazil

"Sustainable Cellulose Nanofibers-Mediated Synthesis of Uniform Spinel Zn-Ferrites Nanocorals for High Performances in Supercapacitors"

Spinel ferrites are versatile, low-cost, and abundant metal oxides with remarkable electronic and magnetic properties, which find several applications. Among them, they have been considered part of the next generation of electrochemical energy storage materials due to their variable oxidation states, low environmental toxicity, and possible synthesis through simple green chemical processing. However, most traditional procedures lead to the formation of poorly controlled materials (in terms of size, shape, composition, and/or crystalline structure). Thus, we report herein a cellulose nanofibers-mediated green procedure to prepare controlled highly porous nanocorals comprised of spinel Zn-ferrites. Then, they presented remarkable applications as electrodes in supercapacitors, which were thoroughly and critically discussed. The spinel Zn-ferrites nanocorals supercapacitor showed a much higher maximum specific capacitance (2031.81 F g−1 at a current density of 1 A g−1) than Fe2O3 and ZnO counterparts prepared by a similar approach (189.74 and 24.39 F g−1 at a current density of 1 A g−1). Its cyclic stability was also scrutinized via galvanostatic charging/discharging and electrochemical impedance spectroscopy, indicating excellent long-term stability. In addition, we manufactured an asymmetric supercapacitor device, which offered a high energy density value of 18.1 Wh kg−1 at a power density of 2609.2 W kg−1 (at 1 A g−1 in 2.0 mol L−1 KOH electrolyte). Based on our findings, we believe that higher performances observed for spinel Zn-ferrites nanocorals could be explained by their unique crystal structure and electronic configuration based on crystal field stabilization energy, which provides an electrostatic repulsion between the d electrons and the p orbitals of the surrounding oxygen anions, creating a level of energy that determines their final supercapacitance then evidenced, which is a very interesting property that could be explored for the production of clean energy storage devices

The role of anthropogenic habitats in freshwater mussel conservation

Anthropogenic freshwater habitats may provide undervalued prospects for long-term conservation as part of species conservation planning. This fundamental, but overlooked, issue requires attention considering the pace that humans have been altering natural freshwater ecosystems and the accelerated levels of biodiversity decline in recent decades. We compiled 709 records of freshwater mussels (Bivalvia, Unionida) inhabiting a broad variety of anthropogenic habitat types (from small ponds to large reservoirs and canals) and reviewed their importance as refuges for this faunal group. Most records came from Europe and North America, with a clear dominance of canals and reservoirs. The dataset covered 228 species, including 34 threatened species on the IUCN Red List. We discuss the conservation importance and provide guidance on how these anthropogenic habitats could be managed to provide optimal conservation value to freshwater mussels. This review also shows that some of these habitats may function as ecological traps owing to conflicting management practices or because they act as a sink for some populations. Therefore, anthropogenic habitats should not be seen as a panacea to resolve conservation problems. More information is necessary to better understand the trade-offs between human use and the conservation of freshwater mussels (and other biota) within anthropogenic habitats, given the low number of quantitative studies and the strong biogeographic knowledge bias that persists.This publication is based upon work from COST Action CA18239, supported by COST (European Cooperation in Science and Technology). A.M.L. was financed by the Institute of Environmental Sciences Jagiellonian University (N18/DBS/000003) and K.N. by the Aragón Government. The authors acknowledge Jarosław Andrzejewski, Bartosz Czader, Anna Fica, Marcin Horbacz, Tomasz Jonderko, Steinar Kålås, Tomasz Kapela, Bjørn Mejdell Larsen, Maciej Pabijan, Katarzyna Pawlik, Ilona Popławska, Joanna Przybylska, Tomasz Przybył, Mateusz Rybak, Kjell Sandaas, Jarosław Słowikowski, Tomasz Szczasny, Michał Zawadzki and Paweł Zowada for providing detailed information on specific examples concerning freshwater mussels in anthropogenic habitats. We thank the editor and two anonymous referees for the valuable suggestions made, which increased the clarity of our manuscript.info:eu-repo/semantics/publishedVersio