REGISTERS OF SEMIOTIC REPRESENTATIONS AIDING THE LEARNING OF COMBINATORIAL SITUATIONS

In order to analyze advances in the resolution of combinatorial situations, due to the identification, conversion and treatment of semiotic registers, two studies were carried out. In the first study, 5th grade students identified, from problems in natural language, registers in trees of possibilities, lists and numerical expressions. The second study, carried out with 5th, 7th and 9th grade students, was configured as an intervention study in which trees or lists were used as an intermediate representation of the departure register (natural language) to the arrival register (numerical expression). The results of the studies confirmed the hypothesis that the conversion to numerical expression is more complex than the conversion to trees or lists. It was also confirmed that trees are more congruent, than lists, with registers in numerical expression. It is concluded that the use of intermediate representations, such as trees or systematic lists, is a good teaching strategy for advances in the combinatorial reasoning of students in the early and middle years of schooling

Construindo árvores de possibilidades para compreensão de relações combinatórias

No presente artigo, defende-se que o uso de árvores de possibilidades pode ser um rico meio de entendimento de diferentes situações combinatórias. Apresenta-se um software que constrói árvores, permitindo que os alunos reflitam sobre importantes relações combinatórias, deescolha e de ordenação de elementos, nos diferentes problemas de produto cartesiano, per-mutação, arranjo e combinação. Árvores de possibilidades são, portanto, representações váli-das para diferentes tipos de problemas combinatórios e podem ser uma ferramenta para ampliação do conhecimento matemático dos estudantes, em particular, no desenvolvimento de seus raciocínios combinatórios

Perfil epidemiológico e terapêutico de pacientes com criptococose atendidos em hospital escola de Santa Maria/RS

Cryptococcosis is a fungal disease caused by yeasts of the complex Cryptococcus neoformans and Cryptococcus gattii. The infection usually occurs by inhaling the basidiospores of the fungus present in the environment. Severe cases occur due to infection of the central nervous system. The disease has a worldwide distribution, mainly associated to the immunocompromised individuals with human immunodeficiency virus (HIV). This study aimed to verify the epidemiological profile and therapeutic protocols of patients diagnosed with cryptococcosis at the Hospital Universitário de Santa Maria (Santa Maria, RS), from March 2010 to March 2017. A total of 46 clinical records were evaluated, the profile of the patients was predominantly Caucasian, aged between 31 and 50 years, with HIV, presenting a CD4 + cell count <100 cells / μL and with a prevalent clinical form neurocryptococcosis. The combination of amphotericin B and fluconazole was the therapeutic protocol adopted in the majority of patients studied.Criptococose é uma doença fúngica causada por leveduras do complexo Cryptococcus neoformans e Cryptococcus gattii. A infecção geralmente ocorre através da inalação dos basidiósporos do fungo presente no ambiente. Casos graves ocorrem devido à infecção do sistema nervoso central. A enfermidade possui distribuição mundial, associada principalmente aos indivíduos imunocomprometidos, portadores do vírus da imunodeficiência humana (HIV). Este estudo objetivou verificar o perfil epidemiológico e os protocolos terapêuticos dos pacientes diagnosticados com criptococose no Hospital Universitário de Santa Maria (Santa Maria, RS), no período de março de 2010 a março de 2017. Avaliaram-se 46 prontuários clínicos, sendo que o perfil dos pacientes observados foi predominantemente do sexo masculino, etnia branca, faixa etária de 31 a 50 anos, portadores de HIV, apresentando taxa de células CD4+<100 células/µL e com forma clínica prevalente, a neurocriptococose. A associação de anfotericina B e fluconazol foi o protocolo terapêutico adotado na maioria dos pacientes estudados

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

Efficient differentiation of Corynebacterium striatum, Corynebacterium amycolatum and Corynebacterium xerosis clinical isolates by multiplex PCR using novel species-specific primers

A multiplex-PCR (mPCR) assay was designed with species-specific primers which generate amplicons of 226 bp, 434 bp and 106 bp for differentiating the species C. striatum, C. amycolatum, and C. xerosis, respectively. mPCR results were 100% in agreement with identifications achieved by 16S rRNA and rpoB gene sequencing and by VITEK-MS.This work was supported by grants from FAPESB (JCB0031/2013) and CAPES (PROCAD 071/2013)

Extended Spectrum Beta-Lactamase-Producing Gram-Negative Bacteria Recovered From an Amazonian Lake Near the City of Belém, Brazil

Aquatic systems have been described as antibiotic resistance reservoirs, where water may act as a vehicle for the spread of resistant bacteria and resistance genes. We evaluated the occurrence and diversity of third generation cephalosporin-resistant gram-negative bacteria in a lake in the Amazonia region. This water is used for human activities, including consumption after appropriate treatment. Eighteen samples were obtained from six sites in October 2014. Water quality parameters were generally within the legislation limits. Thirty-three bacterial isolates were identified as Escherichia (n = 7 isolates), Acinetobacter, Enterobacter, and Klebsiella (n = 5 each), Pseudomonas (n = 4), Shigella (n = 3), and Chromobacterium, Citrobacter, Leclercia, Phytobacter (1 isolate each). Twenty nine out of 33 isolates (88%) were resistant to most beta-lactams, except carbapenems, and 88% (n = 29) were resistant to antibiotics included in at least three different classes. Among the beta-lactamase genes inspected, the blaCTX–M was the most prevalent (n = 12 positive isolates), followed by blaTEM (n = 5) and blaSHV (n = 4). blaCTX–M–15 (n = 5), blaCTX–M–14 (n = 1) and blaCTX–M–2 (n = 1) variants were detected in conserved genomic contexts: blaCTX–M–15 flanked by ISEcp1 and Orf477; blaCTX–M–14 flanked by ISEcp1 and IS903; and blaCTX–M–2 associated to an ISCR element. For 4 strains the transfer of blaCTX–M was confirmed by conjugation assays. Compared with the recipient, the transconjugants showed more than 500-fold increases in the MICs of cefotaxime and 16 to 32-fold increases in the MICs of ceftazidime. Two isolates (Escherichia coli APC43A and Acinetobacter baumannii APC25) were selected for whole genome analysis. APC43A was predicted as a E. coli pathogen of the high-risk clone ST471 and serotype O154:H18. blaCTX–M–15 as well as determinants related to efflux of antibiotics, were noted in APC43A genome. A. baumannii APC25 was susceptible to carbapenems and antibiotic resistance genes detected in its genome were intrinsic determinants (e.g., blaOXA–208 and blaADC–like). The strain was not predicted as a human pathogen and belongs to a new sequence type. Operons related to metal resistance were predicted in both genomes as well as pathogenicity and resistance islands. Results suggest a high dissemination of ESBL-producing bacteria in Lake Água Preta which, although not presenting characteristics of a strongly impacted environment, contains multi-drug resistant pathogenic strains

Evidence of contamination by oil and oil products in the Santos-Sao Vicente estuary, Sao Paulo, Brazil

Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/Sao Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatao city and of another of low anthropogenic influence (Cananeia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/Sao Vicente estuary.CAPES (Brazilian Agency for Science and Technology); Oceanographic Institute of Sao Paulo University; Laboratory of Ecotoxicology and Environmental Chemistry of the University of Algarve; CAPES-PDEE [BEX 2176/07-6]info:eu-repo/semantics/publishedVersio

Granulocyte-Colony Stimulating Factor-Overexpressing Mesenchymal Stem Cells Exhibit Enhanced Immunomodulatory Actions Through the Recruitment of Suppressor Cells in Experimental Chagas Disease Cardiomyopathy

Genetic modification of mesenchymal stem cells (MSCs) is a promising strategy to improve their therapeutic effects. Granulocyte-colony stimulating factor (G-CSF) is a growth factor widely used in the clinical practice with known regenerative and immunomodulatory actions, including the mobilization of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs). Here we evaluated the therapeutic potential of MSCs overexpressing G-CSF (MSC_G-CSF) in a model of inflammatory cardiomyopathy due to chronic Chagas disease. C57BL/6 mice were treated with wild-type MSCs, MSC_G-CSF, or vehicle (saline) 6 months after infection with Trypanosoma cruzi. Transplantation of MSC_G-CSF caused an increase in the number of circulating leukocytes compared to wild-type MSCs. Moreover, G-CSF overexpression caused an increase in migration capacity of MSCs to the hearts of infected mice. Transplantation of either MSCs or MSC_G-CSF improved exercise capacity, when compared to saline-treated chagasic mice. MSC_G-CSF mice, however, were more potent than MSCs in reducing the number of infiltrating leukocytes and fibrosis in the heart. Similarly, MSC_G-CSF-treated mice presented significantly lower levels of inflammatory mediators, such as IFNγ, TNFα, and Tbet, with increased IL-10 production. A marked increase in the percentage of Tregs and MDSCs in the hearts of infected mice was seen after administration of MSC_G-CSF, but not MSCs. Moreover, Tregs were positive for IL-10 in the hearts of T. cruzi-infected mice. In vitro analysis showed that recombinant hG-CSF and conditioned medium of MSC_G-CSF, but not wild-type MSCs, induce chemoattraction of MDSCs in a transwell assay. Finally, MDSCs purified from hearts of MSC_G-CSF transplanted mice inhibited the proliferation of activated splenocytes in a co-culture assay. Our results demonstrate that G-CSF overexpression by MSCs potentiates their immunomodulatory effects in our model of Chagas disease and suggest that mobilization of suppressor cell populations such as Tregs and MDSCs as a promising strategy for the treatment of chronic Chagas disease. Finally, our results reinforce the therapeutic potential of genetic modification of MSCs, aiming at increasing their paracrine actions