A utilização das Tic's no Ensino de História

Vivemos atualmente em um mundo com diversas tecnologias digitais, o que ocasiona mudanças no nosso modo de relacionamento, trabalho, comunicação e estudo. A escola não fica imune a essas mudanças e as Tecnologias de Informação e Comunicação (TIC’s), chegam também no espaço escolar. Compreendemos que os recursos tecnológicos podem auxiliar na prática pedagógica, motivando os alunos na construção do conhecimento histórico. Considerando tal afirmação este artigo faz uma breve retrospectiva sobre o Ensino de História no Brasil e uma revisão bibliográfica sobre o tema. Julgamos este estudo relevante, tendo em vista o reconhecimento, por parte dos professores, sobre a potencialidade das Tic’s como ferramenta auxiliar ao processo de ensino e aprendizagem. Ainda assim, percebemos algumas barreiras que precisam ser superadas, como a falta de formação continuada para que o professor utilize esse recurso e a falta de infraestrutura adequada nas escolas. Pretendemos, com este estudo, colaborar com o debate acerca da utilização das tecnologias no Ensino de História, suas possibilidades e desafios na contemporaneidade

A história do ensino de História no Brasil

O presente artigo faz uma reflexão sobre a constituição da disciplina de História no contexto educacional brasileiro. Abordamos a trajetória do Ensino de História, com ênfase nos períodos de maior discussão sobre os conteúdos curriculares. Dentre eles destacamos o Império, a ditadura militar e os tempos atuais. Recorremos à bibliografia já produzida sobre o Ensino de História no Brasil e concluímos que a História ensinada nas escolas ainda está alicerçada no paradigma de uma históriatradicional que supervaloriza os heróis, as datas comemorativas e a memorização dos fatos. Contrariando assim a perspectiva teórica que a História assume atualmente como campo de conhecimento, o que nos indica uma variação no tempo do Ensino da História, em relação ao tempo de reflexão e produção do campo de conhecimento

Association between Duffy blood group system variants and susceptibility and resistance to malaria in the Brazilian Amazon

The interaction between Duffy blood group proteins and Plasmodium vivax is necessary for the establishment of the erythrocytic phase of malaria, because these molecules act as receptors for the protozoan. This study showed significant associations between Duffy blood group variants and susceptibility and resistance to vivax malaria. In the present study, Duffy blood group genotyping and phenotyping were carried out for 244 individuals living in a Brazilian area where malaria is endemic and P. vivax identification was performed by thick blood smears. Our results showed that 80 individuals were positive and 164 were negative to P. vivax. We registered a high frequency of genotype FYAFYB (47.5%), followed by FYBFY (15.6%), FYAFYA (14.3%), FYBFYB (11.5%), FYAFY (8.6%), and FYFY (2.5%). The frequencies of FYA, FYB, and FY alleles were 55%, 38.8%, and 6.3% in infected individuals, respectively, whereas in non-infected ones they were 36.3%, 45.1%, and 18.6%, respectively. These results demonstrate that FYA allele is more frequent in individuals infected with vivax malaria. The null genotype was not found in infected subjects, but was present in 3.7% of the non-infected individuals. We also found 11.5% discordance between genotype and phenotype. The estimated genetic frequency proved that the population participating in the study did not show genetic balance according to Hardy-Weinberg

Stress conditions in the host induce persister cells and influence biofilm formation by Staphylococcus epidermidis RP62A

INTRODUCTION: Studies have demonstrated that pathogens react to the harsh conditions in human tissues by inducing mechanisms that promote survival. METHODS: Persistence and biofilm-forming ability were evaluated during stress conditions that mimic those in the host. RESULTS: Carbon-source availability had a positive effect on Staphylococcus epidermidis RP62A adhesion during hypoxia, accompanied by a decrease in pH. In contrast, iron limitation led to decreased surface-adherent biomass, accompanied by an increase medium acidification and lactate levels. Interestingly, iron starvation and hypoxia induced persister cells in planktonic culture. CONCLUSIONS: These findings highlight the role of host stress in the virulence of S. epidermidis

A new Kunitz trypsin inhibitor from Erythrina poeppigiana exhibits antimicrobial and antibiofilm properties against bacteria

Erythrina poeppigiana belongs to Fabaceae family (subfamily Papillionoideae) and is commonly found in tropical and subtropical regions in Brazil. Herein, we described the purification and characterization of a new Kunitz-type inhibitor, obtained from E. poeppigiana seeds (EpTI). EpTI is composed by three isoforms of identical aminoterminal sequences with a molecular weight ranging from 17 to 20 kDa. The physicochemical features showed by EpTI are common to Kunitz inhibitors, including the dissociation constant (13.1 nM), stability against thermal (37–100 ◦C) and pH (2–10) ranging, and the presence of disulfide bonds stabilizing its reactive site. Furthermore, we investigated the antimicrobial, anti-adhesion, and anti-biofilm properties of EpTI against Grampositive and negative bacteria. The inhibitor showed antimicrobial activity with a minimum inhibitory concentration (MIC, 5–10 μM) and minimum bactericidal concentration (MBC) of 10 μM for Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus haemolyticus. The combination of EpTI with ciprofloxacin showed a marked synergistic effect, reducing the antibiotic concentration by 150%. The increase in crystal violet uptake for S. aureus and K. pneumoniae strains was approximately 30% and 50%, respectively, suggesting that the bacteria plasma membrane is targeted by EpTI. Treatment with EpTI at 1x and 10 x MIC significantly reduced the biofilm formation and prompted the disruption of a mature biofilm. At MIC/2, EpTI decreased the bacterial adhesion to polystyrene surface within 2 h. Finally, EpTI showed low toxicity in animal model Galleria mellonella. Given its antimicrobial and anti-biofilm properties, the EpTI sequence might be used to design novel drug prototypes

Sublethal necroptosis signaling promotes inflammation and liver cancer

It is currently not well known how necroptosis and necroptosis responses manifest in vivo. Here, we uncovered a molecular switch facilitating reprogramming between two alternative modes of necroptosis signaling in hepatocytes, fundamentally affecting immune responses and hepatocarcinogenesis. Concomitant necrosome and NF-κB activation in hepatocytes, which physiologically express low concentrations of receptor-interacting kinase 3 (RIPK3), did not lead to immediate cell death but forced them into a prolonged "sublethal" state with leaky membranes, functioning as secretory cells that released specific chemokines including CCL20 and MCP-1. This triggered hepatic cell proliferation as well as activation of procarcinogenic monocyte-derived macrophage cell clusters, contributing to hepatocarcinogenesis. In contrast, necrosome activation in hepatocytes with inactive NF-κB-signaling caused an accelerated execution of necroptosis, limiting alarmin release, and thereby preventing inflammation and hepatocarcinogenesis. Consistently, intratumoral NF-κB-necroptosis signatures were associated with poor prognosis in human hepatocarcinogenesis. Therefore, pharmacological reprogramming between these distinct forms of necroptosis may represent a promising strategy against hepatocellular carcinoma

The association between frailty and MRI features of cerebral small vessel disease

Abstract: Frailty is a common syndrome in older individuals that is associated with poor cognitive outcome. The underlying brain correlates of frailty are unclear. The aim of this study was to investigate the association between frailty and MRI features of cerebral small vessel disease in a group of non-demented older individuals. We included 170 participants who were classified as frail (n = 30), pre-frail (n = 85) or non-frail (n = 55). The association of frailty and white matter hyperintensity volume and shape features, lacunar infarcts and cerebral perfusion was investigated by regression analyses adjusted for age and sex. Frail and pre-frail participants were older, more often female and showed higher white matter hyperintensity volume (0.69 [95%-CI 0.08 to 1.31], p = 0.03 respectively 0.43 [95%-CI: 0.04 to 0.82], p = 0.03) compared to non-frail participants. Frail participants showed a non-significant trend, and pre-frail participants showed a more complex shape of white matter hyperintensities (concavity index: 0.04 [95%-CI: 0.03 to 0.08], p = 0.03; fractal dimensions: 0.07 [95%-CI: 0.00 to 0.15], p = 0.05) compared to non-frail participants. No between group differences were found in gray matter perfusion or in the presence of lacunar infarcts. In conclusion, increased white matter hyperintensity volume and a more complex white matter hyperintensity shape may be structural brain correlates of the frailty phenotype