Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto

About: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto is a based out in . It is known for research contribution in the topics: Population & Catalysis. The organization has 2143 authors who have published 3674 publications receiving 71071 citations. The organization is also known as: FFCLRP & FFCLRP-USP.

Weighted -Asymptotically -Periodic Solutions of a Class of Fractional Differential Equations

Abstract: We study the existence of weighted -asymptotically -periodic mild solutions for a class of abstract fractional differential equations of the form , where is a linear sectorial operator of negative type.

Recent demographic history of cactophilic Drosophila species can be related to Quaternary palaeoclimatic changes in South America

Abstract: Aim The aim of this paper is to investigate the influence and extent of past climatic changes on South American biota. To this end, we establish phylogeographical hypotheses for a monophyletic group of four cactophilic species of Drosophila (the Drosophila serido haplogroup) found in xeromorphic vegetation in Brazil. The effects of Quaternary palaeoclimatic oscillations on the demographic fluctuations of our biological model and its sister group Drosophila antonietae are investigated. Location Areas of eastern Brazil with open vegetation, including seasonally dry tropical forest (SDTF) areas and montane savannas, which are disjunctly distributed in eastern Brazil. We also analysed populations of sand dune vegetation from littoral areas in Brazil. Methods Nucleotide information from 630 bp of the cytochrome c oxidase subunit I gene from 441 individuals was used to perform a series of statistical analyses to infer a phylogeographical hypothesis for each species and to date the divergence time between the D. serido and D. antonietae haplogroups. Results All of the analysed species experienced population expansion during the Pleistocene, probably following the historical migratory routes that have been proposed for the expansion of SDTFs in Brazil. A bottleneck event in the Holocene was inferred for Drosophila seriema, probably due to ecological factors related to the geographical distribution of the host plant. The divergence time for the D. serido and D. antonietae haplogroups was calculated to have occurred during the early Pleistocene. Main conclusions Geographical and chronological evidence suggests that the major vicariant events between the D. serido and D. antonietae haplogroups, as well as the demographic fluctuations in each of the species within these lineages, could be related to the causal effects of Quaternary palaeoclimatic changes on the spatial dynamics of the SDTFs in Brazil.

RNA-sequencing analysis of Trichophyton rubrum transcriptome in response to sublethal doses of acriflavine

Abstract: The dermatophyte Trichophyton rubrum is an anthropophilic filamentous fungus that infects keratinized tissues and is the most common etiologic agent isolated in human dermatophytoses. The clinical treatment of these infections is challenging because only few antifungal drugs are commercially available. To understand the mode of action of cytotoxic drugs against fungi, we evaluated the time-dependent effects of acriflavine on T. rubrum transcriptome using high-throughput RNA-sequencing (RNA-seq) technology. RNA-seq analysis generated approximately 200 million short reads that were mapped to the Broad Institute's Dermatophyte Comparative Database before differential gene expression analysis was performed. By employing a stringent cut-off threshold of −1.5 and 1.5 log2-fold changes in gene expression, a subset of 490 unique genes were found to be modulated in T. rubrum in response to acriflavine exposure. Among the selected genes, 69 genes were modulated at all exposure time points. Functional categorization indicated the putative involvement of these genes in various cellular processes such as oxidation-reduction reaction, transmembrane transport, and metal ion binding. Interestingly, genes putatively involved in the pathogenicity of dermatophytoses were down-regulated suggesting that this drug interferes with the virulence of T. rubrum. Moreover, we identified 159 novel putative transcripts in intergenic regions and two transcripts in intron regions of T. rubrum genome. The results provide insights into the molecular events underlying the stress responses of T. rubrum to acriflavine, revealing that this drug interfered with important molecular events involved in the establishment and maintenance of fungal infection in the host. In addition, the identification of novel transcripts will further enable the improvement of gene annotation and open reading frame prediction of T. rubrum and other dermatophyte genomes.