Estudo palinológico dos sedimentos Devonianos, Bacia do Paraná: perfil Ponta Grossa - Campo Largo

The present communication deals with the palynological observations on the Devoniam sediments from Parana Basin, Paraná State, Brazil. This is the first of a series of research work under study and records observations on the paleoecology and biostratigraphy of this region. Though the assemblage is not very rich it has some characteristic spores along with acritarchs which suggests a lower Denovian age (Emsian) to the sediments studied. General comments based on palynological assemblage are also attempted.Este trabalho apresenta algumas observações sobre os palinomorfos dos sedimentos devonianos da Bacia do Paraná, no Estado do Paraná. Trata-se do primeiro de uma série de estudos que estão em andamento, visando melhor compreensão da bioestratigrafia e paleoecologia do Devoniano naquele Estado. A assembléia palinológica por nós estudada e identificada, embora escassa, conte'm esporos e acritarcas que comparados com os de palinozonas devonianas de outras regiões, sugerem uma idade, preliminar, devoniana inferior (Emsiano)

Preliminary identification of the bioremediation limiting factors of a clay bearing soil contaminated with crude oil

Bioremediation is an attractive alternative to treat soils contaminated with petroleum hydrocarbons. However, the effectiveness of biodegradation process can be limited by both contaminant characteristics and its bioavailability in soil. This work aims at establishing a preliminary procedure to identify the main factor (hydrocarbon recalcitrance or its bioavailability) that impairs the biodegradation, possibly resulting in low remediation efficiencies. Tests in soil microcosms were carried out applying biostimulation and bioaugmentation techniques. Similar experiments were conducted using liquid medium containing crude oil and microorganisms, both of them extracted from a weathered contaminated soil sample, nutrients and microbial inoculum constituted of Rhodoturula glutinis and Nocardia nova. After 30 days, highest microcosms biodegradation levels (98.8%) were obtained with bioaugmentation in liquid medium, pointing out that the main problem of petroleum hydrocarbon utilization by microorganisms was associated to its availability and not only to the intrinsic recalcitrancy of remaining pollutants

The silent extinction of freshwater mussels in Portugal

Freshwater mussels are one of the most threatened animal groups in the world. In the European Union, threatened and protected mussel species are not adequately monitored, while species considered to be common and widespread receive even less attention. This is particularly worrying in the Mediterranean region, where species endemism is high and freshwater habitats are severely affected by water scarcity. In the absence of hard data on population trends, we report here a long-term comparison of freshwater mussel assemblages at 132 sites covering 15 different hydrological basins in Portugal. This study reveals a widespread decline of 60 % in the number of sites and 67 % in the overall abundance of freshwater mussels across Portugal over the last 20 years, indicating that all species are rapidly declining and threatened with extinction. These results show that current legislation and conservation measures are largely ineffective and highlight the importance of updating the Habitats Directive to enforce standard monitoring protocols for threatened species in the European Union and to extend monitoring to other freshwater species thought to be common and widespread. Efficient water management, restrictions on irrigation expansion in important biodiversity areas, mitigation of hydrological changes and loss of aquatic habitat connectivity caused by physical alterations are urgently needed to reverse these declining population trends. For the severely endangered species Margaritifera margaritifera, Potomida littoralis, and Unio tumidiformis, where populations are now critically low, more urgent action is needed, such as ex-situ conservation, protection of remaining populations and large-scale habitat restoration.We would like to thank Jake Dimon, José Tourais, Filipe Rolo, and Elza Fonseca for their help in the surveys. This research was developed under the project EdgeOmics - Freshwater Bivalves at the edge: Adaptation genomics under climate-change scenarios (PTDC/CTA-AMB/3065/2020) funded by the Portuguese Foundation for Science and Technology (FCT) through national funds. FCT also funded MLL under contract 2020.03608.CEECIND, EF under contract CEECINST/00027/2021/CP2789/CT0003, AGS under the grants SFRH/BD/137935/2018 and COVID/DB/152933/2022, and JGN under the grant 2020.04637. BD. The baseline survey was funded by the project “Documentos Estruturantes” (POA 1.100021) of the Instituto da Conservaçã da Natureza

Genome-wide signatures of complex introgression and adaptive evolution in the big cats.

The great cats of the genus Panthera comprise a recent radiation whose evolutionary history is poorly understood. Their rapid diversification poses challenges to resolving their phylogeny while offering opportunities to investigate the historical dynamics of adaptive divergence. We report the sequence, de novo assembly, and annotation of the jaguar (Panthera onca) genome, a novel genome sequence for the leopard (Panthera pardus), and comparative analyses encompassing all living Panthera species. Demographic reconstructions indicated that all of these species have experienced variable episodes of population decline during the Pleistocene, ultimately leading to small effective sizes in present-day genomes. We observed pervasive genealogical discordance across Panthera genomes, caused by both incomplete lineage sorting and complex patterns of historical interspecific hybridization. We identified multiple signatures of species-specific positive selection, affecting genes involved in craniofacial and limb development, protein metabolism, hypoxia, reproduction, pigmentation, and sensory perception. There was remarkable concordance in pathways enriched in genomic segments implicated in interspecies introgression and in positive selection, suggesting that these processes were connected. We tested this hypothesis by developing exome capture probes targeting ~19,000 Panthera genes and applying them to 30 wild-caught jaguars. We found at least two genes (DOCK3 and COL4A5, both related to optic nerve development) bearing significant signatures of interspecies introgression and within-species positive selection. These findings indicate that post-speciation admixture has contributed genetic material that facilitated the adaptive evolution of big cat lineages

Soil nitrogen absorption by corn as affected by crop residues addition

Avaliou-se o efeito da incorporação da leguminosa feijão-bravo-do-Ceará (Canavalia brasiliensis) e do capim-colonião (Panicum maximum) sobre o conteúdo de C, N e frações da matéria orgânica de um solo Podzólico Vermelho-Amarelo e sobre a produção de matéria seca e acúmulo de N em milho, cultivado em casa de vegetação por 102 dias. Os tratamentos constaram da adição de diferentes doses (20, 40 e 60 t.ha-1) de feijão-bravo e capim-colonião, além de N-mineral e do controle. Observou-se incrementos lineares de 0,088 e 0,068 mg C.g-1 solo, proporcionados pela incorporação de uma tonelada de feijão-bravo e capim-colonião, respectivamente. O conteúdo de C das frações alcalino-solúveis do material húmico não foi alterado, o que não se verificou na fração humina e matéria orgânica livre, com aumento no conteúdo, principalmente nos tratamentos com feijão-bravo. O conteúdo de N aumentou linearmente com a incorporação de feijão-bravo e colonião, correspondendo, respectivamente, a 0,0103 e 0,004 mg N.g-1 solo para cada tonelada do material, detectando-se um aumento na fração ácido fúlvico livre com a incorporação de 40 e 60 t.ha-1 de feijão-bravo, quando comparado ao controle. A incorporação de feijão-bravo aumentou o teor de N do solo, proporcionando maior produção e acúmulo de N no milho, semelhante à obtida com a aplicação de 560 kg.ha-1 de N.Various levels of Canavalia brasiliensis and Panicum maximum (20, 40 and 60 t.ha-1) were incorporated into a red-yellow podzolic soil, which was planted with corn. After 102 days in the greenhouse, the C, N, and organic matter fractions content of the soil and the N level dry matter of the plants were measured. One ton of Canavalia brasiliensis or Panicum maximum produced a linear increase of 0.088 or 0.068 mg C.g-1 soil, respectively. The C content of the alkali-soluble soil fraction of the humic fraction was unaltered, but was increased in the humin and free organic material fractions, especially by Canavalia brasiliensis. Nitrogen content increased linearly with the application of one ton of Canavalia brasiliensis or Panicum maximum to 0.0103 or 0.004 mg N.g-1 soil, respectively. There was a rise in the free fulvic acid fraction in soil treated with 40 and 60 t.ha-1 of Canavalia brasiliensis, compared with the control. Canavalia brasiliensis increased the N content of the soil and enhanced the N content of the corn to a level equivalent to that obtained with the application of 560 kg.ha-1 of N

Jejunal Diverticular Perforation due to Enterolith

Jejunal diverticulosis is a rare entity with variable clinical and anatomical presentations. Although there is no consensus on the management of asymptomatic jejunal diverticular disease, some complications are potentially life-threatening and require early surgical treatment. Small bowel perforation secondary to jejunal diverticulitis by enteroliths is rare. The aim of this study was to report a case of small intestinal perforation caused by a large jejunal enterolith. An 86-year-old woman was admitted with signs of diffuse peritonitis. After initial fluid recovery the patient underwent emergency laparotomy. The surgery showed that she had small bowel diverticular disease, mainly localized in the proximal jejunum. The peritonitis was due to intestinal perforation caused by an enterolith 12 cm in length, localized inside one of these diverticula. The intestinal segment containing the perforated diverticulum with the enterolith was removed and an end-to-end anastomosis was done to reconstruct the intestinal transit. The patient recovered well and was discharged from hospital on the 5th postoperative day. There were no signs of abdominal pain 1 year after the surgical procedure. Although jejunal diverticular disease with its complications, such as formation of enteroliths, is difficult to suspect in patients with peritonitis, it should be considered as a possible source of abdominal infection in the elderly patient when more common diagnoses have been excluded